Abstract
PS06-001
Poster Viewing Session VI
Impairment of neurovascular coupling after subarachnoid hemorrhage in vivo
1University of Munich Medical Center, Institute for Stroke and Dementia (ISD), Munich, Germany
2Ludwig-Maximilians University (LMU), Graduate School of Systemic Neurosciences (GSN), Munich, Germany
3University of Vermont, Department of Pharmacology, Burlington, United States
Abstract
Keywords
Subarachnoid hemorrhage, Neurovascular coupling, CO2 reactivity, in vivo, ex vivo
PS06-002
Poster Viewing Session VI
New insights into brain blood flow regulation during stroke: Role of electrical communication
1University of Western Ontario, Physiology and Pharmacology, London, Canada
2University of Calgary, Physiology and Pharmacology, Calgary, Canada
3University of Copenhagen, Biomedical Sciences, Copenhagen, Denmark
4University of Calgary, Calgary, Canada
5University of Western Ontario, London, Canada
Abstract
Arterial networks coordinates blood flow delivery to the brain in accordance with metabolic demand. To change blood flow magnitude, vasoactive stimuli generated in the grey matter must dilate cortical surface vessels concerted with penetrating arterioles. These coordinated multi-segmental responses require a common signal (i.e. charge) to be shared among neighboring vascular cells. This process is enabled by gap junctions, intercellular pores that coordinate membrane potential, cytosolic [Ca2+] and myosin light chain phosphorylation responses, along the arterial tree. In this study, we sought to understand intercellular communication in the cerebral circulation and its impact on driving physiological (functional hyperemia) and pathophysiological (collateral flow recruitment) responses. Electrical stimuli spread effectively from cell-to-cell in cerebral arteries, isolated from mice and resected human tissue, in an endothelium dependant manner. Compromising gap junctional communication through the genetic deletion of Connexin40 (Cx40-/-), attenuated electrical communication and functional hyperemic responses spreading from penetrating arterioles to the cortical surface vessels. Compromised cell-to-cell communication impaired the recruitment of collateral circulation, during and after experimental stroke, reducing brain blood flow and expanding tissue injury. In closing, our findings demonstrate electrical communication to be an integral component of the cerebral circulation; established by gap junctional resistance and linked to the endothelium. Cell to cell communication drives multi-segmental responses in cerebrovascular networks and its impairment compromises the brain's ability to: 1) match blood flow delivery with metabolic demand; and 2) to salvage brain tissue during stroke. As such, the mechanistic significance of cell to cell communication have to be considered; for understanding flow responses in the cerebral circulation and especially while designing therapeutic paradigms that target blood flow augmentation in the brain.
PS06-003
Poster Viewing Session VI
Disruption of cortical arterial network is associated with the severity of transient neurological events after direct bypass surgery in adult moyamoya disease
1Gifu University Graduate School of Medicine, Department of Neurosurgery, Gifu, Japan
2Hyogo College of Medicine, Department of Neurosurgery, Nishinomiya, Japan
Abstract
PS06-004
Poster Viewing Session VI
Investigating the impact of obesity on post-stroke complications
1University of Manchester, Division of Neuroscience & Experimental Psychology Health, Manchester, United Kingdom
Abstract
PS06-005
Poster Viewing Session VI
Novel substrates of the small vessel disease related HTRA1 protease identified by proteomics
1Institute for Stroke and Dementia Research (ISD), University Hospital of the Ludwig- Maximilians-Universität (LMU), Munich, Germany
2German Center for Neurodegenerative Diseases (DZNE) Munich, Neuroproteomics, Klinikum rechts der Isar, Technical University Munich (TUM), Munich, Germany
3Institute for Advanced Study, Technical University Munich (TUM), Garching, Germany
4Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
Abstract
Loss-of-function mutations in the HTRA1 gene encoding the serine protease high temperature requirement A1 have been identified as a cause for both dominant and recessive forms of small vessel disease (SVD). The molecular mechanisms and signaling pathways involved in the development of these disorders are incompletely understood. We applied a high-end label-free quantification mass spectrometry (LC-MS/MS) approach to determine the proteomes of cerebral microvessels isolated from wild-type and HTRA1 knockout mice. Overall we quantified 3.884 proteins (≥2 unique peptides) among them 117 differentially expressed proteins with marked overrepresentation of proteins that were upregulated in HTRA1-deficient animals. Among upregulated proteins were known substrates of HTRA1 such as latent transforming growth factor (TGFβ)-binding proteins and downstream targets including TGFβ. We further identified several novel proteins with established roles in other types of SVD and vascular development. We confirmed enrichment of several of these targets by immunostaining of isolated microvessels and biochemical approaches. Using in-vitro proteolytic cleavage assays we further showed that several of these targets including members of the WNT signaling pathway are indeed direct substrates of HTRA1. Collectively, our data establish molecular links between different types of SVD and suggest a possible role of dysregulated WNT signaling in HTRA1-related SVD.
PS06-006
Poster Viewing Session VI
MicroRNA-103-1 is involved in the pathogenesis of ischemic brain damage and may represent a stroke peripheral diagnostic marker
1Federico II University of Naples, Neuroscience, Reproductive and Odontostomatological Sciences, Naples, Italy
Abstract
Ischemic stroke is a multi-faced pathology that involves gene reprogramming. Among those genes whose expression is influenced by cerebral ischemia can be included the plasmamembrane protein sodium-calcium exchanger-1 (NCX1), that, by controlling Ca2+ and Na+ fluxes in a bidirectional way across the synaptic plasma membrane, plays a pivotal role in the regulation of ionic homeostasis in physiological and pathophysiological conditions such as brain ischemia. We have recently identified a microRNA (miR-103-1) able to selectively modulate NCX1 expression in the brain during stroke and whose inhibition by anti-mir-103-1,intracerebroventicularly infused in ischemic rats, causes NCX1 upregulation in brain cortex and striatum accompanied by brain damage reduction.
Since it has been established that microRNAs (miRNAs) can be included in vesicles called exosomes and released in the blood, it has been hypothesized a potential use of these non-coding RNAs as biomarkers for neurological disorders.
In this work, we firstly investigated the expression of miRNA-103-1 in the ischemic penumbra of animals subjected to brain ischemia or to the neuroprotective phenomenon called “Remote Postconditioning” (RemPost), a strategy in which a subliminal ischemia applied to a “distant” organ is able to protect the brain from a previous harmful ischemic insult. As expected, the expression of miRNA103-1 increased after harmful brain ischemia and was dramatically reduced after remote postconditioning.
More interestingly, we were able to demonstrate that miR-103-1 may serve as peripheral prognostic/diagnostic marker of stroke, since its expression level in plasma samples of rats subjected to brain ischemia is proportionate to brain ischemic damage.
These results suggest that miRNA103-1 expression is a marker of ischemic brain damage and, more intriguingly, it is released in the blood in a manner proportionate to brain damage, thus representing a good candidate for stroke diagnosis.
PS06-007
Poster Viewing Session VI
Does long-lasting high sodium intake predispose cerebral blood vessels to stroke? Comparison with sodium-dependent hypertension
1Mossakowski Medical Research Centre Polish Academy of Sciences, Neurosurgery, Warsaw, Poland
2Mossakowski Medical Research Centre Polish Academy of Sciences, Metabolic-Telemetric Station, Warsaw, Poland
3Medical University of Warsaw, Experimental and Clinical Physiology, Warsaw, Poland
Abstract
High sodium intake is a risk factor of cardio-vascular diseases including arterial hypertension and its major complication - stroke. To what extent prolonged high sodium intake per se affects cerebral blood vessels is not clear. To answers this, the experiments were performed on Sprague Dawley rats (SD) divided into following groups: SD with sham unilateral nephrectomy fed standard (0.25% Na, SHAMNS) or high sodium (4% Na) diet (SHAMHS) and SD with unilateral nephrectomy fed high sodium (4% Na) diet (UNXHS). Once a week in the course of 28 days the blood pressure was measured noninvasively and plasma sodium concentration was determined. After 28 days MCAs were harvested and the responses to extravascular administration of: endothelin 1 (ET-1: 10−10, 5×10−10, 10−9 , 5×10−9, 10−8 M), AT1 angiotensin receptor agonist (AT1
The response of the MCA to vasoconstrictors did not differ between the groups. High sodium diet per se did not impair MCA response to ATP (SHAMHS vs SHAMNS) whereas in the group UNXHS this response was significantly diminished when compared to SHAM groups. Administration of L-NAME resulted in significantly smaller constriction of the MCA in SHAMHS and UNXHS in comparison with the response observed in SHAMNS.
The results of this study show that: 1) high sodium diet leads to impaired basal release of NO in the rat MCA, 3) loss of the response of the rat MCA to endothelium-dependent vasodilators in sodium-dependent hypertension occurs at the early stage of the disease.
PS06-008
Poster Viewing Session VI
Structure of the brain bioelectric activity in the stroke patients with various types of polymorphism of the genes ACE, eNOS, MTHFR
1D.F. Chebotarev Institute of Gerontology, National Academy of Medical Sciences, Kiev, Ukraine
2Institute of Molecular Biology and Genetics, National Academy of Sciences, Kiev, Ukraine
Abstract
Patients of the homozygotic bearers of mutant variant 4a gene eNOS, in contrast to the patients with 4b4b genotype, displayed the high level of power within a range of the slow (delta- and theta-) rhythms in all areas of injured hemisphere against a background of low frequency and power of the alpha-rhythm.
In the heterozygotic patients-bearers of polymorphism GA of gene prothrombin, the frequency of alpha-rhythm in all areas of the intact hemisphere was statistically higher.
The patients-bearers of polymorphism TT of the gene MTHFR versus the patients with polymorphism CC showed, respectively, a statistically higher power in the range of delta and theta-rhythms and a statistically lower power of alpha-rhythm in the injured hemisphere,
PS06-009
Poster Viewing Session VI
Enhanced therapeutic potential of nano-curcumin against subarachnoid hemorrhage-induced blood-brain barrier disruption through inhibition of inflammatory response and oxidative stress
1Taishan Medical University, Key Lab of Cerebral Microcirculation in Universities of Shandong, Taian, China
Abstract
PS06-010
Poster Viewing Session VI
Clinical and etiological profiles of adult patients with post stroke seizures in Bishkek
1Kyrgyz State Medical Academy, Neurology and Medical Genetics Department, Bishkek, Kyrgyzstan
Abstract
The most common identified etiological factors were aneurisms - 17,9%, AVM -15,4%, ischemic stroke −28,2%, hemorrhage stroke −38,5%.
The seizure types were generalized tonic clonic seizures - 29%, secondary generalized seizures - 45%, and simple partial seizures - 26%.
41% of seizures occur in the first 24 hours after stroke.
Risk factors for recurrent seizures were large cortical strokes, severe strokes, recurrent strokes and late seizures.
PS06-011
Poster Viewing Session VI
Direct carotid exposure for neuroendovascular approaches
1Soonchunhyang University Hospital, Neurosurgery, Bucheon City, Korea, Republic of
Abstract
PS06-012
Poster Viewing Session VI
Xenon as a therapy in experimental intracerebral hemorrhage
1Duke University Medical Center, Anesthesiology, Durham, United States
2Hebei General Hospital, Hebei University Medical University, Neurology, Shijiazhuang, China
3The Second Affiliated Hospital of Xi' an Jiaotong University, Anesthesiology, Xi' an, China
4The First Affiliated Hospital of Kunming Medical University, Intensive Care Unit, Kunming, China
Abstract
Exp 1) Randomly received 0, 15, 30 or 45% xenon for 20 h beginning at 2 h post-injection;
Exp 2) 30% xenon for 0, 4, 8 or 20 h beginning at 2 h;
Exp 3) 30% xenon for 20 h beginning at 2, 4, 6, or 12 h;
Exp 4) comparison of efficacy in male and female mice; and
Exp 5) efficacy in the mouse autologous blood injection model. In all experiments, body weight and rotarod examined pre-injury, 1, 3, 7 and 28-days post-injury.
Neurological function2 and brain histology were examined (blinded) at 28-days post-injury.
Exp 1) All xenon doses improved 28-day outcome, with 30% most efficacious;
Exp 2) A minimum of 8 hours xenon exposure post-ICH was required for efficacy;
Exp 3) Xenon efficacy decreased with time to onset of treatment, 2 hours post-ICH was most effective;
Exp 4) Xenon produced similar levels of efficacy in both male and female mice;
Exp 5) Xenon improved autologous blood injection outcome, with the largest effect seen when treatment began 2 hours post-injection.
1. Sheng et al. Anesthesiology doi: 10.1097/ALN.0b013e3182746b81
2. Taninishi et al. JCBFM 2016 pii: 0271678X15616980
PS06-013
Poster Viewing Session VI
Prevalence of ischemic stroke in relation to season and its gender features in the northern part of Fergana valley of Uzbekistan
1Tashkent Medical Academy, Neurology, Tashkent, Uzbekistan
Abstract
With regard to type of stroke and gender differences there were also determined some regularities in distribution of the lethal outcomes in different months. Among men in (IS) the maximal number of lethal outcomes was noted in spring, and minimal - in summer (32,2 and 16,9%, respectively). In women with IS maximal cases of lethal outcomes was registered in autumn, and minimal - in summer (30,1 and 20,5%, respectively).
PS06-014
Poster Viewing Session VI
Stroke patterns in rural South India - Five years experience in a rural stroke centre
1Dr. Vanchilingam Hospital, Department of Stroke, Thanjavur, India
Abstract
Cortical venous sinus thrombosis accounted for 228 (9%) of the total stroke population. Age range of (6 yrs–73 yrs).
PS06-015
Poster Viewing Session VI
MiR-210 boosts the protective effects of NPC-EXs on neurons and astrocytes against hypoxia/reoxygenation-induced injury
1Wright State University, Department of Pharmacology & Toxicology, Dayton, United States
2Affiliated Hospital of Guangdong Medical University, Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Institute of Neurology, Zhanjiang, China
3Wuhan Sports University, College of Health Science, Wuhan, China
4Affiliated Hospital of Guangdong Medical University, Institute of Neurology, Dayton, United States
Abstract
Transplantation of neural progenitor cells (NPCs) has therapeutic effects on ischemic stroke. Increasing evidence suggest that extracellular exosomes (EXs) mediate the beneficial effects of stem cells by delivering microRNAs (miRs) to target cells. It has been shown that miR-210 offers anti-apoptotic effect on neurons and its circulating level positively correlates with outcome of stroke patients. Here, we investigated whether miR-210 enriched NPC-EXs (NPC-EXsmiR-210) have better protective effects on neurons/astrocytes subjected to hypoxia/reoxygenation (H/R) injury. NPC-EXsmiR-210 or NPC-EXsmiR-con were collected from NPCs transfected with miR-210 mimics or miR-control. Neurons/astrocytes were subjected to hypoxia (1% 02) for 6 hrs, followed by reoxygenation with application of vehicle, NPC-EXsmiR-con or NPC-EXsmiR-210 (50 ug/ml) in culture medium. After 24 hrs, neuronal axon length and glutamate uptake ability of astrocytes were evaluated. Cell apoptosis (TUNEL assay), mitochondria membrane potential (MMP; JC-1 staining), and ROS production (DHE staining) were analyzed. The expressions of miR-210 downstream molecules (neuronal pentraxin1/NP1, ephrin-A3) and apoptotic genes (cyt c, caspase- 3) in cells, and concentrations of cytokines (BDNF, IL-1β, IL-6) in culture media were determined by western blot or ELISA. Results showed: 1) The level of miR-210 in NPC-EXsmiR-210 was 10-fold of that in NPC- EXsmiR-con, and NPC-EXsmiR-210 upregulated miR-210 level in H/R-injured neurons/astrocytes; 2) Compared to vehicle, NPC-EXsmiR-con decreased H/R-induced neural and astrocytic apoptosis and dysfunctions (axon outgrowth and glutamate uptake ability), which were associated with significant downregulation of NP1/ephrin-A3, increase of MMP, BDNF and IL-6 release, decrease of ROS production, cyt c, cleaved caspase-3, IL-1β; 3) NPC-EXsmiR-210 were more effective than NPC-EXsmiR-con on all of these effects, except for changes in IL-6 and IL-1β. Taken together, our data demonstrate that miR-210 enrichment can enhance the protective effects of NPC-EXs on neurons/astrocytes from H/R injury through targeting the NP1/ephrin-A3 pathways (Fig 1).
PS06-016
Poster Viewing Session VI
MicroRNA miR-21 is neuroprotective against focal cerebral ischemia
1University of Wisconsin at Madison, Cellular and Molecular Pathology, Madison, United States
2University of Wisconsin at Madison, Neurological Surgery, Madison, United States
Abstract
PS06-017
Poster Viewing Session VI
Silencing of deSUMOylating isopeptidase 2 increases neuronal vulnerability after ischemic-like stress
1Charité - Universitätsmedizin Berlin, Center for Stroke Research, Department of Experimental Neurology, Berlin, Germany
Abstract
Gareau & Lima, 2010
Shin et al., 2012
PS06-018
Poster Viewing Session VI
Microglial-conditioned media treated with geniposide and ginsenoside Rg1 on ischemic neurons
1Academy of Chinese Medical Sciences, Institute of Basic Theory, Beijing, China
2Xiyuan Hospital, Institute of Basic Medical Sciences, Beijing, China
3Academy of Chinese Medical Sciences, The Experimental Research Center, Beijing, China
4Academy of Chinese Medical Sciences, Xiyuan Hospital, Beijing, China
Abstract
The synergistic mechanism underlying the effects of multi-component combined drug use for complex diseases remains to be fully elucidated. Microglial activation following ischemia can either affect neural survival or cause neuronal injury. The aim of the present study was to determine the synergistic effect of geniposide and ginsenoside Rg1, based on microglial-neuronal communication. N2a neuronal cells were divided into the following seven groups: Control group; normal cultured microglial cells in conditioned medium (N-MG-CM) group; oxygen-glucose deprivation (OGD) model group; OGD-injured MG-CM (I-MG-CM) group; geniposide-treated MG-CM (G-MG-CM) group; ginsenoside Rg1-treated MG-CM (R-MG-CM) group; and combination-treated MG-CM (C-MG-CM) group. A series of assays were used to detect the effects of the different MG-CM on neurons in terms of: (i) cell viability, determined using a Cell Counting Kit-8; (ii) lactate dehydrogenase (LDH) leakage rate; (iii) expression of NMDAR1 and activated caspase-3, detected using western blotting; (iv) mitochondrial transmembrane potential, determined by JC-1; and (v) mitochondrial ultrastructural features, determined using electron microscopy. The experimental results demonstrated that MG-CM including the integrated use of geniposide and ginsenoside Rg1 significantly protected neuronal cell viability and inhibited LDH leakage, suppressed the expression of N-methyl-D-aspartate receptor subunit 1 and activated caspase-3, increased the mitochondrial transmembrane potential and improved the mitochondrial ultrastructure. MG-CM from separately used geniposide or ginsenoside Rg1 demonstrated differential neuroprotection at different levels. These findings revealed that the synergistic drug combination of geniposide and ginsenoside Rg1 in the treatment of stroke is a feasible approach for use.
PS06-019
Poster Viewing Session VI
Investigating the effects of chronic stress on the neurovascular unit
1Charité-Universitätsmedizin Berlin, Berlin, Germany
2Universitätsmedizin Rostock, Rostock, Germany
Abstract
PS06-020
Poster Viewing Session VI
Differential protein expression profiling of focal cerebral after human cerebral endothelial cell transplantation
1Chonnam National University Medical School, Department of Forensic Medicine, Gwangju, Korea, Republic of
2Center for Creative Biomedical Scientists, Chonnam National University Medical School, Gwangju, Korea, Republic of
3Chonnam National University Medical School, Department of Neurology, Gwangju, Korea, Republic of
Abstract
This work was carried out with the support of the “Cooperative Research Program for Agriculture Science & Technology Development” and National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. NRF-2016R1A2B4008316).
PS06-021
Poster Viewing Session VI
Elevating MicroRNA-122 in blood improves outcome via modulating Nos2 after middle cerebral artery occlusion in rats
1University of California at Davis, Neurology, Sacramento, United States
Abstract
Based upon our previous findings that microRNA-122 (miR-122) was decreased in peripheral blood of both humans and rats after ischemic stroke, we hypothesized that elevating miR-122 in blood might improve outcomes after ischemic stroke.
Using the in vivo polyethylene glycol 2000 (PEG)-liposome based miRNA transfection system and the rat middle cerebral artery occlusion (MCAO) model, we recently demonstrated that intravenous (i.v.) miR-122 mimic, given immediately after MCAO, elevated miR-122 in peripheral blood, prevented neurological impairments, and reduced brain infarction volume by 90% after MCAO in rats. Moreover, the results showed that miR-122 mimic, given 6 hr after MCAO, attenuates neurological impairments, and reduced brain infarction volume by 54% after MCAO in rats.
Using Taqman PCR based assays, we demonstrate fourteen direct miR-122 target genes (e.g. Nos2, Vcam1, Clic4, Ucp2, Dlg2, and others) decrease in blood leukocytes following miR-122 mimic treatment after MCAO in rats. Focusing on ONE miR-122 target gene (Nos2), we demonstrate that miR-122 mimic decreases Nos2 expression in brain microvascular endothelial cells (BMVECs) after MCAO in rats.
These results show that Nos2 is decreased in leukocytes and BMVECs following miR-122 mimic treatment after MCAO, which likely contributes to therapeutic effects of miR-122 mimic on ischemic stroke.
PS06-022
Poster Viewing Session VI
The EphB/ephrinB receptor -ligand system promotes the inflammatory response upon ischaemia
1Heidelberg University/Institute of Physiology and Pathophysiology, Heidelberg, Germany
Abstract
Ischaemic strokes are within the most common causes for disability in the industrialized world. The EphB/ephrinB system system causes bi-directional signal transmission and is known for the activation of glial cells, gliosis, and the transmigration of activated monocytes. Nevertheless, little is known about the mechanisms and involvement of this system in the inflammatory response in the acute and early subacute phase upon an infarction.
RNA-microarray analysis using EphB2 deficient and wild type mice subjected to transient middle cerebral artery occlusion (tMCAo) showed a stronger inflammatory response in EphB2 holding animals. Nevertheless, no differences in the transmigration of neutrophils were observed between the genotypes. Further, microglia and astrocytes did not show differences in the abundance, migration or proliferation between the genotypes. Additionally, a bead assay with primary cultured murine microglia showed no influence of the EphB/ephrinB system on the phagocytic activity. However, primary microglia and astrocytes do react to hypoxic conditions in combination with glucose deprivation by increasing the expression of the membrane-bound ligand ephrin-B2. When, in turn, stimulated with EphB2, astrocytes increase their expression of pro-inflammatory cytokines and thus become activated. In contrast, high amounts of cytokines in the medium decrease the ephrinB expression in astrocytes suggesting a self-regulating mechanism. These results indicate a pro-inflammatory role of the EphB/ephrinB system upon stroke. Indeed, EphB2-/- mice show significantly smaller infarction and oedema upon tMCAo. The functional outcome of these mice was consistent with this difference.
In summary, the EphB/ephrinB system is involved in the reaction to ischaemia in the brain and in immunoactive glia cells in particular. Astrocytes do react to EphB2 in a pro-inflammatory manner. Moreover, microglia and astrocytes increase their ephrin-B-ligand expression upon hypoxia, which potentially makes them more responsive to the EphB2 receptor. The exact cellular mechanism by which ephrin-B2 evokes possible detrimental effects remains to be identified.
PS06-023
Poster Viewing Session VI
Characterization of glial cells during the chronic stage of ischemic stroke in rats
1Center for Neuroscience Research, Institute of Biomedical Science and Technology, Konkuk University, Seoul, Korea, Republic of
2School of Medicine, Konkuk University, Medical Science, Seoul, Korea, Republic of
3Konkuk University School of Medicine, Rehabilitation Medicine, Seoul, Korea, Republic of
Abstract
PS06-024
Poster Viewing Session VI
Effect of RGS5 on vasculature remodeling after experimental stroke
1Lund University, Department of Clinical Science Lund, Lund, Sweden
2Scania University Hospital, Department of Neurology, Lund, Sweden
Abstract
(1) Özen et al., Brain pericytes acquire a microglial phenotype after stroke. Acta Neuropathol (2014)
(2) Cho et al., Pericyte-specific expression of Rgs5: implications for PDGF and EDG receptor signaling during vascular maturation. The FASEB Journal (2003)
(3) Berger et al. Regulator of G-protein signsling-5 induction in pericytes coincides with active vessel remodeling during neovascularization. Blood (2005)
(4) Nisancioglu et al., Generation and Characterization of rgs5 mutant mice. Molecular and Cellular Biology (2008)
PS06-025
Poster Viewing Session VI
Longitudinal metabolic evolution of rat cortex
1Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
2University of Geneva, Geneva, Switzerland
Abstract
The ability of 1H MRS to identify stroke damage, predict stroke outcome (neuronal loss or recovery) and estimate ischemic onset times based on metabolite concentrations has been shown. In this study, we aimed to evaluate whether localized 1H MRS at ultra-short time in combination with another MR method, namely MR angiography (vasculature images), could be applied for diagnosis purpose on rat upon global ischemia (4-VO) in a 14.1T magnet. The second aim of this study was to assess longitudinal metabolic evolution of cortex upon a short period of transient global ischemia.
We applied one-stage anterior approach to achieve 4VO in adult male Wistar rats (300–350 g). The MIP images illustrated the typical vascular structure of rat head, i.e. CCAs, VAs, BA and the circle of willies etc (Figure 1a). After 4VO, the MIP images showed that nearly all signals originated from major arteries, were significantly diminished (Figure 1a). 1H MRS showed strong changes upon a compelete 4VO (Figure 1b). We further studied animals before, during and after a complete 15-min 4VO. Once the vertebral arteries were occluded completely, 1H MRS of cortex, a 1-min temporal resolution of metabolite evolution was obtained. Once 4VO was achieved remotely, phosphocreatine (PCr) dropped, creatine (Cr) and lactate (Lac) elevated (Figure 1c). When reperfusion was restored by releasing two occluders, PCr recovered while Cr dropped. With the restoration of perfusion, lactate decreased gradually. Further evolution of these metabolites was also observed in animals hours (1 h, 2 h, 3 h and 8 h) and days (D1, D2 and D3) after such brief ischemia (Figure 1d). A transient elevation of glutamine (Gln) was observed after the restoration of perfusion, consistent with excitoxicity, which was reported in mice after transient focal ischemia.
We conclude that 1H MRS assessment of cortical metabolite changes during and immediately after cerebral ischemia is feasible.
PS06-026
Poster Viewing Session VI
B cell-mediated stroke recovery in female mice
1UT Southwestern Medical Center, Neurology and Neurotherapeutics, Dallas, United States
Abstract
PS06-027
Poster Viewing Session VI
The double edged sword of immunostimulation after stroke
1Charité Universitätsmedizin Berlin, Berlin, Germany
Abstract
PS06-028
Poster Viewing Session VI
Periodontitis modulates peripheral inflammatory cell function and contributes to worse outcome after ischaemic stroke
1University of Manchester, Manchester, United Kingdom
Abstract
PS06-029
Poster Viewing Session VI
The dynamics of energy metabolism in brain after ischemia/reperfusion injury: an animal model study using high-Gz acceleration
1Oita University, Faculty of Welfare and Health Sciences, Oita, Japan
2Oita University Faculty of Medicine, School of Medicine, Oita, Japan
3National Defense Medical College, Department of Physiology, Tokorozawa, Japan
4JASDF Aeromedical Laboratory, 2nd Division, Tachikawa, Japan
5Oita University Faculty of Medicine, Department of Physiology, Oita, Japan
Abstract
PS06-030
Poster Viewing Session VI
Efficacy of Alteplase® in a mouse model of acute ischemic stroke: a retrospective pooled analysis
1University of Caen Normandy, INSERM U 1237, Caen, France
2University of Caen Normandy, ESRP, Caen, France
Abstract
The debate over the fact that experimental drugs proposed for the treatment of stroke fail in the translation to the clinical situation, has attracted considerable attention in the literature. In this context, we present a retrospective pooled analysis of a large dataset from pre-clinical studies, in order to examine the effects of early versus late administration of intravenous recombinant tissue type plasminogen activator (rt-PA).
We collected data from 26 individual studies from 9 international centers (13 researchers, 716 animals) that compared rt-PA to controls, in a unique mouse model of thromboembolic stroke induced by an in situ injection of thrombin into the middle cerebral artery. Studies were classified into early (< 3 h) versus late (≥3 h) drug administration. Final infarct volumes, assessed by histology or MRI, were compared in each study and the absolute differences were pooled in a random-effect meta-analysis. The influence of time of administration was tested.
When compared to saline controls, early rt-PA administration was associated with a significant benefit (absolute difference = −6.63 mm3; 95% CI, −9.08 to −4.17; I2 = 76%) whereas late rt-PA treatment showed a deleterious effect (+5.06 mm3; 95% CI, +2.78 to +7.34; I2 = 42%, Pint < 0.00001). Results remained unchanged following subgroup analyses.
Our results provide the basis needed for the design of future pre-clinical studies on recanalization therapies using this model of thromboembolic stroke in mice. The power analysis reveals that a multi-center trial would require 123 animals per group instead of 40 for a single center trial.
PS06-031
Poster Viewing Session VI
LabCIRS - a lightweight critical incident reporting system for academic research departments
1Charité Universitätsmedizin Berlin, Experimentelle Neurologie, Berlin, Germany
Abstract
Recent meta analyses show that insufficient reproducibility of preclinical studies leads to serious drawbacks in translation from experimental research to clinical treatment. Based on the experience from clinical studies, multiple guidelines for the improvement of the reseach quality in academic biomedical research laboratories emerged. Among many others measures, implementation of error management systems, within or outside the context of structured quality management systems was suggested.
Errors, mishaps, and mistakes of variable severity frequently occur in biomedical research laboratories. Although errors can negatively impact data integrity, experimental outcomes, animal welfare, personnel safety, or viability of expensive reagents or machinery, they are reported only sporadically or erratically, or might even be covered up for fear of negative consequences.
To improve our error culture we decided to implement an anonymous critical incident reporting system (CIRS), which has become a standard in clinical medicine but has to our knowledge never been implemented in the context of academic basic research.
We developed, tested and implemented LabCIRS, a simple, open-source software tool written in the Python programming language as a user friendly, simple on-line critical incident reporting system for research groups, laboratories or institutions. LabCIRS is accepted by all members of the department, has led to the emergence of a mature error culture, and has made the laboratory a safer and more communicative environment. Initial concerns that implementation of such a measure may lead to a ‘surveillance culture' which would stifle scientific creativity turned out to be unfounded.
PS06-032
Poster Viewing Session VI
Modulation of the peri-infarct neurovascular function by β-Hydroxybutyrate
1Sunnybrook Research Institute, Toronto, Canada
2Yale School of Medicine, New Haven, United States
3Krembil Research Institute, Toronto, Canada
Abstract
Due to the oxygen dependence of the glycolytic pathway [1], production of ATP in ischemic tissue is accompanied by generation of Reactive Oxygen Species (ROS). The aim of this work was to test the efficacy of providing a ketone body, an alternative metabolic substrate, in the acute post-ischemic phase so as to reduce ROS production and improve neurovascular recovery.
To examine the susceptibility of the neurogliovascular unit to metabolic modulation in the acute stage of focal ischemic stroke, we delivered a ketone body (β-Hydroxybutyrate, BHB; 100 mg/kg i.p.) one hour after ischemic insult induced by direct cortical microinjection of endothelin-1 in sensorimotor cortex of adult rats (800 pico moles, as in our previous work [2]). We contrasted functional vascular responses to hypercapnia imaged on continuous arterial spin labeling (CASL) MRI and resting state field potentials in BHB- vs. vehicle-treated cohort 48 hours after stroke induction.
In line with our previous study [2], transient hypercapnia in the vehicle treated cohort elicited exaggerated vascular functional responses in the peri-ischemic tissue (1.8 ± 0.5 times larger in lesioned vs. un-lesioned hemisphere). In contrast, BHB treated cohort shows reduced lateralization of the CBF increase. After CASL experiments, resting state local field potentials showed decreased theta-band power in the peri-lesional tissue (0.75 ± 0.22 mV/mV*Hz-1 lesioned/un-lesioned hemisphere), which was partially rescued (0.91 ± 0.02 mV/mV*Hz-1 lesioned/un-lesioned hemisphere) in the BHB-treated cohort.
Our data suggests that BHB administration may be beneficial for the neurovascular unit recovery. As opposed to other neurocentric approaches, our project shows the efficacy of a pleiotropic treatment that may benefit multiple cells in the neurovascular unit.
[1] Demopoulus, et al (1980) The free radical pathology and the microcirculation in the central nervous system disorders
[2] Lake et al. (2016) Neurovascular unit remodelling in the subacute stage of stroke recovery. Neuroimage. In press
PS06-033
Poster Viewing Session VI
Hematoxylin-eosin stained pathology of hyperacute focal cerebral ischemia at 1 hour after middle cerebral artery occlusion in rats: correlation with diffusion MRI
1Chungbuk National University Hospital, Radiology, Cheongju, Korea, Republic of
2Chung-Ang University, Department of Chemistry, Seoul, Korea, Republic of
3Korea Basic Science Institute, Bioimaging Research Team, Ochang, Korea, Republic of
4Korea Research Institute of Bioscience and Biotechnology, National Primate Research Center, Ochang, Korea, Republic of
5Chung-Ang University, Medical Research Institute, Seoul, Korea, Republic of
6Philips Healthcare, Clinical Science, Seoul, Korea, Republic of
7Korea Institute of Science and Technology, Center for BioMicrosystems, Brain Science Institute, Seoul, Korea, Republic of
8Korea University of Science and Technology, Biomedical Engineering, Seoul, Korea, Republic of
Abstract
[ADC image and pathology (Cresyl violet, MAP2, H&E)]
PS06-034
Poster Viewing Session VI
Role of NADPH oxidase in mitochondrial dysfunction following transient global cerebral ischemia in rats
1Panjab University, Biophysics, Chandigarh, India
2Panjab University, Biochemistry, Chandigarh, India
Abstract
Cerebral ischemia results from occlusion of major arteries of brain and reactive oxygen species play major role in its pathology. Major sources of ROS are NADPH oxidase (PHOX) and mitochondria and they both are interlinked. Activation of one enzyme system lead to activation of other, resulting in oxidative stress which lead to neurodegeneration. Present study tried to explore the role of PHOX inhibitor to attenuate the mitochondrial injury following ischemia in rats. Ischemia model established by occlusion of both common carotid arteries for 15 minutes. Mitochondrial membrane potential (ψm) and activity of mitochondrial complexes were studied. Apoptosis were studied by TUNEL assay and gene expression of various markers cyt c, Bcl2, Bax, caspase3 and 9 were seen. Neurodegeneration were observed by fluorojade staining. PHOX activity and ROS levels were significantly increased post 7 days of ischemic injury. Activity of mitochondrial complexes I, II, IV, V were significantly decreased following ischemia. Consequently there was decrease in mitochondrial membrane potential that lead to change in membrane transition pore. Increased cytochrome c and other apoptotic genes initiated the programmed cell death which was reflected by TUNEL positive cells and Flourojade B positive cells in cortical and hippocampal region. The administration of apocynin significantly reduce the PHOX activity and hence ROS production which result in decreased mitochondrial injury and apoptosis. Inhibition of NADPH oxidase activity is a therapeutic target to attenuate the mitochondrial injury following ischemia.
PS06-035
Poster Viewing Session VI
Characterisation of Translocator Protein (TSPO) expression in the brain in rodent models of neuroinflammation
1King's College London, Institute of Psychiatry, Psychology and Neuroscience, Neuroimaging, London, United Kingdom
2Wellcome Trust Consortium for Neuroimmunology of Mood Disorders and Alzheimer’s Disease, London, United Kingdom
3King's College London, Institute of Psychiatry, Psychology and Neuroscience, Centre for Developmental Neurobiology, London, United Kingdom
4King's College London, Institute of Psychiatry, Psychology and Neuroscience, Psychological Medicine, London, United Kingdom
Abstract
Mitochondrial membrane Translocator Protein (TSPO) is implicated in many physiological functions including steroidogenesis, stress sensing, autophagy and cholesterol transport, but its exact roles remain to be elucidated(1). Despite the uncertainty, a significant interest in TSPO is based on the ability to detect its expression in vivo by PET, via the use of radiolabelled ligands. It appears that TSPO expression is increased during inflammation in the CNS and thus TSPO ligand-binding is a useful biomarker of neuroinflammation in psychiatric and neurological research. It is not yet clear whether TSPO increase is linked to early acute neuroinflammation(2), a later 'inflammation-resolving phase'(3) or whether it is preferentially shown in the prolonged chronic neuroinflammation.
In order to examine which type of inflammatory processes affect TSPO, we measured TSPO expression in several rat models of neuroinflammation: systemic acute administration of bacterial endotoxin lipopolysaccharide (LPS), systemic chronic administration of LPS, intracerebral administration of LPS and photothrombotic stroke in the sensorimotor cortex. All these models demonstrate a prominent and persistent activation and proliferation of microglia, the brain's resident immune cells.
Despite evidence of microglial activation (immunohistochemistry), we did not detect increased TSPO binding (3H-PK11195 autoradiography) in the brains of rats treated with a single systemic dose of LPS. TSPO was clearly increased in stroke, and its time-course matched that of microglia proliferation (but not activation), whereas in the model of intracerebral administration TSPO increase was immediately present. We further explored the origin and source of TSPO expression, by conducting analyses of blood brain barrier permeability and immunohistochemical co-localization studies. We present a picture of TSPO in neuroinflammation that is complex and dependant on the nature and timing of the insult.
1 Selvaraj et al (2015) Trends in Endocrinology & Metabolism 26, 341.
2 Sandiego at al (2015) PNAS 112, 12468.
3 Loggia et al (2015) Brain 138, 604.
PS06-036
Poster Viewing Session VI
Microglial calcium release-activated calcium (CRAC) channel inhibition improves outcome from experimental traumatic brain injury and microglia-induced neuronal death
1University of California, San Francisco, Neurology, San Francisco, United States
2San Francisco Veterans Affairs Medical Center, Neurology, San Francisco, United States
3CalciMedica, La Jolla, United States
Abstract
Store-operated Ca2+ entry (SOCE) mediated by CRAC channels contribute to calcium signaling in immune cells. CRAC channels consist of the endoplasmic reticulum resident Ca2+-sensing protein stromal interaction molecule 1 (STIM1) and the calcium channel protein ORAI1 located in the plasma membrane. Prolonged Ca2+ entry through CRAC channels activates nuclear factor of activated T cells (NFAT), involved in T cell proliferation and cytokine expression. Microglia contain CRAC channels, but little is known whether they play a role in brain injury. We studied novel CRAC channel inhibitors to explore their therapeutic potential in microglia-mediated injury. A neuron cell line (Neuro-2A, N-2A) was cultured alone or with microglial BV2 cells then exposed to 2h oxygen glucose deprivation (OGD). Some cultures were treated with a novel CRAC channel inhibitor. Toll-like receptor (TLR) -3, -4 agonists or IFNγ were also used to activate microglia. Western blots revealed the presence of CRAC channel proteins STIM1 and ORAI1 in microglia. CRAC channel inhibition decreased NO release and inflammatory proteins iNOS and COX-2 expression in activated microglia, but did not affect STIM1 or ORAI1 expression. CRAC channel inhibitors also reduced agonist induced intracellular calcium accumulation in BV2 cells. Agonists also activated JNK1/2 kinase, NFAT, NF-kB, CREB & STAT1 in microglia, but only JNK1/2 kinase & NFAT were attenuated by inhibitor. OGD decreased N2A neuronal cell viability, further exacerbated by BV2 cells, but neuronal cells were protected by CRAC channel inhibition (n = 5, *p < 0.05). We then treated male C57/BL6 mice exposed to experimental brain trauma (TBI) and found that CRAC channel inhibition led to decreased lesion size, brain hemorrhage and improved neurological deficits (n = 6–7/grp, *p < 0.05). We suggest a novel anti-inflammatory approach for treating acute brain injury. Our observations also shed light on new calcium signaling pathways, not previously described in brain injury models.
PS06-037
Poster Viewing Session VI
Triggering receptor expressed on myeloid cells-2 (TREM2) biases towards M2 microglial responses and its deficiency worsens outcome after experimental traumatic brain injury
1University of California, San Francisco, Neurology, San Francisco, United States
2San Francisco Veterans Affairs Medical Center, Neurology, San Francisco, United States
3University of California, San Francisco, Medicine, San Francisco, United States
4San Francisco Veterans Affairs Medical Center, Medicine, San Francisco, United States
Abstract
Triggering receptor expressed by myeloid cells-2 (TREM2) is a surface receptor present on microglia and macrophages. It was first described as a receptor of the innate immune system which bound pathogens and led to their phagocytosis. TREM2 deficiency leads to dementia, and we recently showed that its deficiency leads to worsened outcome after experimental stroke. Thus, TREM2 may be an important molecule in the clearance of injured cells paving the way towards recovery and repair. Here, we explored whether TREM2 might also play a role in experimental brain trauma TBI. Male TREM2 knockout (TREM Ko) or wildtype (Wt) mice (n = 12/group) were subjected to controlled cortical impact (CCI), then assessed for neurological function at 1, 3, 7 & 14 d later. Mice were assessed for neurological deficit (Bederson score), lateralization on an elevated body swing test, and foot faults from a ladder test. Brains were then harvested for histology. TREM Ko mice had worsened neurological recovery compared to Wt on all three functional studies (p < 0.05) and had markedly increased lesion volumes (2 × larger than Wt, p < 0.01). This was also associated with reduced resorption of injured brain tissue amongst Ko mice. We also studied Neuro2a cells in combination with BV2 microglia. Microglial treatment with IL-4 induced a M2 (anti-inflammatory) phenotype as determined by arginase 1, CD206 & YM1 induction, and also increased TREM2 expression. When TREM2 was silenced using siRNA, arginase1 induction was decreased while iNOS (M1, pro-inflammatory) was increased. TREM2 silencing in BV2 cells also decreased neuronal phagocytosis in response to microglial activators. These results indicate that TREM2 deficiency worsens outcome from experimental TBI, and that TREM2 plays a role in the phagocytosis of injured brain cells, and leads towards a M2 phenotype.
PS06-038
Poster Viewing Session VI
The potential neuroprotective role of a histone deacetylase inhibitor, sodium butyrate, after neonatal hypoxia-ischemia
1Mossakowski Medical Research Centre Polish Academy of Sciences, NeuroRepair Department, Warsaw, Poland
Abstract
PS06-039
Poster Viewing Session VI
Role of DAMPs-mediated NETosis during the acute inflammation in the postischemic brain
1Inha University School of Medicine, Inchoen, Korea, Republic of
Abstract
Cerebral ischemia leads to brain damages via a complicated pathological events such as excitotoxicity, inflammation, apoptosis, and peri-infarct depolarization. Brain inflammation after stroke is known to be slowly proceeded with low impacts on forming brain infarction However, neutrophils are quickly recruited in response to brain damages and the role of neutrophils is not fully understood after recruitment. We investigated recruitment of neutrophils and formation of neutrophil extracellular traps (NETs) in permanent middle cerebral artery occlusion (pMCAO) model. H&E and immunohistochemistry identified the recruitment of neutrophil in leptomeningeal artery and corpus callosum after pMCAO. Immunofluorescence staining revealed that the number of CitH3 (NETosis marker) positive cells, which showed intact, partial lytic, or lytic, increased in leptomeninges from 6 hours, in cortex from 12 hours, and in striatum from 24 hours after pMCAO. At 24 hours after pMCAO, lytic CitH3 positive cells prevailed in cortical arteriole and microvessel, which supposed to induce vascular damage and subsequent infiltration of immune cells. Furthermore, neutrophils were also recruited in cerebrospinal fluid (CSF) after pMCAO, which identified CitH3 positive cells. Interestingly, neutrophils in CSF and corpus callosum after pMCAO were shrunken, compared with blood neutrophils. Because cerebral ischemia is non-infectious disease, we assumed danger associated molecular patterns (DAMPs) stimulated neutrophils to migrate to damaged brain parenchyma and form NET in the postischemic brain. The level of CitH3 and NET formation were increased by treatment of HMGB1, glutamate, or ATP, which were suppressed by respective antagonist. Together these results indicated that the recruitment of neutrophils and NET formation in the postischemic brain were regulated by DAMPs and damaged vessel by NETosis accelerated subsequent recruitment of other immune cells, followed by brain inflammation.
PS06-040
Poster Viewing Session VI
Immunomodulatory properties of human bone marrow mesenchymal stem cells and extracellular vesicles derived from these cells after their transplantation into focal brain ischemic rats
1Mossakowski Medical Research Centre, PAS, NeuroRepair Department, Warsaw, Poland
2The Johns Hopkins University School of Medicine, Russel H. Morgan Department of Radiology and Radiological Science, Division of MR Research, Baltimore, United States
Abstract
PS06-041
Poster Viewing Session VI
Changes in local and global measures of resting state functional connectivity in the rat LPS model of neuroinflammation
1University of Oxford, Department of Psychiatry, Oxford, United Kingdom
2King's College London, Institute of Psychiatry, Psychology and Neuroscience, Neuroimaging, London, United Kingdom
3Wellcome Trust Consortium for Neuroimmunology of Mood Disorders and Alzheimer’s Disease, London, United Kingdom
4King's College London, Institute of Psychiatry, Psychology and Neuroscience, Psychological Medicine, London, United Kingdom
Abstract
Lipopolysaccharide (LPS) causes a generalized immune reaction, which also affects the CNS. The resulting sickness behaviour, characterized by a loss of appetite and hypolocomotion, is linked to depressive illness and efforts are made to understand how the neuroinflammation causes behavioural symptoms. Here we aimed to characterize the brain connectivity in rats treated with LPS, in order to develop in vivo translatable biomarker of neuroinflammation.
Male SD rats were imaged by resting state functional MRI (rsfMRI) before, 24 hr and 2 weeks after 0.5 mg/kg ip LPS (n = 18) or saline (VEH, n = 19). All LPS treated rats showed expected sickness behaviour and weight loss (+0.5 g VEH, -25 g LPS, p < 0.0001) at 24 h; widespread neuroinflammation in this model (inflammatory cytokines and activated microglia in the brain) was confirmed in separate cohorts of rats. rsfMRI data were pre-processed using FSL's FEAT and FIX tools, converted into graph networks (154 ROIs) and statistically analyzed for changes in graph theoretical measures using GRETNA1 and NBS2.
First, the presences of robust homotopic connectivity networks were assessed in each animal to validate the methodology, using ICA (A). Then, LPS and VEH networks were compared at the global, nodal and edge level at each time point. Differences were detected at 24 hr, but not at 2 weeks, after treatment.
We observed changes in localized network properties including higher modularity and increased nodal clustering coefficients in LPS rats, which may suggest a more fragmented network in the inflamed brain due to transient attenuation of existing connections. The hotspot areas for decreased connectivity were subcortical, particularly the thalamus. Moreover we found significantly strengthened and attenuated edge connections between several regions in LPS rats (B).
1. Wang J. et al (2015) Front Hum Neurosci 9, 1
2. Zalesky A. et al (2010) NeuroImage 53, 1197
Figure
PS06-042
Poster Viewing Session VI
The role of pentraxin 3 (PTX3) in inflammation and neuroprotection after ischaemic stroke
1University of Manchester, Manchester, United Kingdom
Abstract
The inflammatory response occurring after an ischaemic stroke is a key mediator of stroke pathogenesis. Thus, targeting inflammation and promoting repair mechanisms are attractive therapeutic approaches for stroke. A recent study has shown the acute phase protein pentraxin 3 (PTX3) as potentially neuroprotective as it reduces blood brain barrier (BBB) damage and promotes resolution of oedema, angiogenesis and neurogenesis after experimental stroke. Our aim was to investigate this further, confirming neuroprotective actions of PTX3 in vitro, and identifying possible underlying mechanisms by studying PTX3 recruitment of neutrophils.
Neurones were treated with 20 µM N-methyl-D-aspartate (NMDA), PTX3 (1000 ng/ml) or 20 µM NMDA and PTX3 (1000 ng/ml). In separate studies, neutrophils were isolated from wild type (WT) and PTX3 knock out (KO) mice and allowed to transmigrate through interleukin-1 beta (IL1β) activated brain endothelial (bEnd5) cells for 24 h. Subsequently, neutrophil transmigration was quantified with a cell haemocytometer. Naive or transmigrated WT and KO neutrophils were seeded onto primary mouse cortical neurones and incubated for 20 h. In all studies, neuronal cell death was quantified with lactate dehydrogenase (LDH) assay.
We found in vitro that neuronal cell death induced by NMDA was significantly reduced 3 fold in cultures treated with a combination of NMDA (20 µM) and PTX3 (1000 ng/ml) compared with cultures treated with NMDA (20 µM) alone. We found that neutrophil transmigration was significantly reduced 3 fold in PTX3 KO mice compared with WT controls. Naïve WT and KO neutrophils were significantly less neurotoxic than transmigrated WT and KO neutrophils, however, no significant difference in neurotoxicity was observed between WT and KO transmigrated neutrophils.
These data suggest that PTX3 has neuroprotective properties and may also play a role in inflammation by regulating neutrophil transmigration. Our findings suggest that PTX3 is a promising therapeutic target for future stroke therapies.
PS06-043
Poster Viewing Session VI
A translational model of moderate perinatal asphyxia reveals lasting behavioral deficits in the absence of focal neuronal loss
1Institute of Experimental Medicine of the Hungarian Academy of Sciences, Budapest, Hungary
2Semmelweis University, 1st Department of Pediatrics, Budapest, Hungary
3Spanish Cardiovascular Research Centre (CNIC), Madrid, Spain
4CROmed Translational Research Centers, Budapest, Hungary
5Semmelweis University, Department of Biophysics and Radiation Biology, Budapest, Hungary
6University of Helsinki, Department of Biosciences and Neuroscience Center, Helsinki, Finland
Abstract
Epidemiological studies suggest that even moderate birth asphyxia may play a role in the development of psychiatric disorders. Our goal was to characterize a recently developed translational rodent model of perinatal asphyxia which does not include any surgical intervention, in order to investigate putative mechanisms through which asphyxia may contribute to the subsequent behavioral alterations.
Wistar rat pups on postnatal day 7 were exposed to a gas mixture containing 4% O2, 20% CO2 and 76% N2, or to room air for 15 min at 37 oC. Rats were subjected to comprehensive behavioral assessment from 24 h post-asphyxia into adulthood. Brain perfusion and microglial activation were investigated with SPECT and MRI in vivo. Inflammation and neuronal injury were studied by using cytometric bead array, immunofluorescence and confocal/super-resolution microscopy.
Brain perfusion changes, microglial activation and neuronal apoptosis were detected 24 h after asphyxia. In adult rats, changes in vesicular glutamate transporter (VGLUT-2) levels in synaptic terminals were found in the CA1-CA3 regions of the hippocampus and in the prefrontal cortex, whereas no signs of focal neuronal loss or white matter injury were observed. Neonatal asphyxia did not cause significant sensory-motor deficits in pups or in adult rats. However, long-term functional testing identified increased anxiety of asphyxiated rats in the Elevated Plus Maze and spatial memory deficits were found in the Morris water maze test. Moreover, changes in emotional and memory functions in adult post-asphyxia rats were accompanied by increased impulsivity-like behavior and attention deficits in the Delay Discounting paradigm and in the 5-choice test.
Moderate neonatal asphyxia evoked acute neuroinflammation in the absence of major neuronal injury and resulted in dysfunction of glutamatergic terminals in conjunction with ADHD-like behavioral symptoms in adulthood. This model may provide clinically relevant insight into mechanisms of the diverse psychiatric disturbances in humans who have suffered from moderate birth asphyxia.
PS06-044
Poster Viewing Session VI
Phosphoinositide 3-kinase χ ties chemoattractant- and adrenergic control of microglial motility
1Jena University Hospital, Institute of Molecular Cell Biology, Jena, Germany
2Leibnitz Institute for Age Research, Fritz Lipmann Institute (FLI), Jena, Germany
Abstract
Microglial motility is tightly controlled by multitude of agonistic and antagonistic factors. Chemoattractants, released after brain infection or damage, provoke directed migration of microglia to the pathogenic incident. In contrast, noradrenaline and other stress hormones have been shown to suppress microglial movement. Here we asked for the signaling reactions involved in the balanced control of microglial motility.
Using pharmacological and genetic approaches we identified the lipid kinase activity of phosphoinositide 3-kinase species χ (PI3Kχ) as an essential mediator of microglial migration. We verified with appropriate in vitro assays using immortalized and primary microglial cells that C5a acts as most effective inducer of microglial migration. The PI3Kχ dependence of Iba1-positive cell motility was confirmed under in vivo conditions. We could shown that Iba1-positive cell migration in direction of a focal stab injury revealed reduced cell number in the immediate vicinity of the injury site indicating reduced directed migration in PI3Kχ knockout brains. Furthermore, noradrenaline induced cAMP production and subsequent stimulation of protein kinase A (PKA) was verified as inhibitory principle of microglial migration. Decrease of microglial migration after norepinephrine stimulation could be rescued by co-treatment with the PKA inhibitor H89.
Therefore, inhibition of PI3Kχ lipid kinase activity by protein kinase A was disclosed as mechanism causing suppression of microglial migration by noradrenaline. Together these data characterize PI3Kχ as a nodal point in the control of microglial motility.
PS06-045
Poster Viewing Session VI
Characteristics of primary rat microglia isolated from mixed cultures using two different methods
1Massachusetts General Hospital, Department of Radiology and Neurology, Charlestown, United States
Abstract
PS06-046
Poster Viewing Session VI
Contribution of inflammasomes to ischaemic stroke
1University of Manchester, Manchester, United Kingdom
Abstract
PS06-047
Poster Viewing Session VI
Telomere maintenance, mitochondrial biogenesis and cell cycle control: an mRNA study of microglia activation states
1Charité-Universitätsmedizin Berlin, Berlin, Germany
2Universitätsmedizin Rostock, Rostock, Germany
3German Center for Neurodegenerative Disease (DZNE), Berlin, Germany
4DZHK (German Centre for Cardiovascular Research), partner site Berlin, Berlin, Germany
Abstract
PS06-048
Poster Viewing Session VI
Reactive oxygen species (ROS)- responsive nanotechnology: Therapeutic action of nanoparticles in stroke
1University of Manchester, Faculty of Biology, Medicine and Health, Manchester, United Kingdom
Abstract
Ischaemic stroke is characterised by a potent inflammatory response that contributes to brain injury. Inflammatory responses are associated with oxidative stress, production of highly oxidising compounds, such as superoxide anion, hydrogen peroxide and hypochlorite (all of which are reactive oxygen species (ROS)). There is evidence to suggest that immediately after acute ischaemic stroke there is a rapid increase in the production of ROS, which have both directly toxic and inflammatory effects. Therefore, one way to protect the brain after ischaemic stroke is by blocking the actions of ROS in order to reduce inflammation. Recently, oxidation-responsive poly(propylene sulphide (PPS) nanoparticles, that predominantly scavenge upregulated concentrations of extracellular ROS, have been developed. Therefore, we tested the hypothesis that these nanoparticles are effective at scavenging ROS produced by cells of the brain, and can therefore limit inflammation and protect the brain tissue after ischaemic stroke.
Primary mouse mixed glial cells (astrocytes and microglia) were treated with 0.5 µg/ml of inflammatory mediator lipopolysaccharide (LPS). Poly(propylene sulphide) (PPS) nanoparticles significantly decreased LPS-induced production of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α), detected with enzyme linked immunosorbent assay (ELISA). Similar results were obtained for the analysis of nitric oxide (NO) (in the form of nitrite). PPS nanoparticles significantly decreased nitrite production in immortalised murine microglial cell cultures (BV-2) treated with 1 µg/ml LPS, as detected with griess reagent system. Exposure of PPS nanoparticles (1–5 mg/ml) to 15 micromolar hydrogen peroxide (H2O2) for 24 hours significantly decreased H2O2 concentration in a concentration-dependent manner, detected with ROS-Glo™ H2O2 Assay.
PPS nanoparticles caused a dose-dependent decrease of nitrite, H2O2, IL-6 and TNF-α production. These data suggest that PPS nanoparticles may be scavenging ROS, thus decreasing ROS stimulation of cells to produce inflammatory cytokines. Therefore, PPS nanoparticles can be considered as anti-oxidant and anti-neuroinflammatory therapy for ischaemic stroke.
PS06-049
Poster Viewing Session VI
Cerebral blood flow, optic nerve sheath diameter and neurological status evaluation in patients submitted to post-traumatic decompressive craniectomy and late cranioplasty
1Cristo Redentor Hospital, Intensive Care Medicine, Porto Alegre, Brazil
2Cristo Redentor Hospital, Neurosurgery, Porto Alegre, Brazil
3Federal University of Rio Grande do Sul - UFRGS, Pos Graduation Program in Medical Science, Porto Alegre, Brazil
4Universidad de la República del Uruguay, Facultad de Medicina, Montevideo, Uruguay
Abstract
PS06-050
Poster Viewing Session VI
Sex differences in brain blood flow in rugby players with concussions
1Rutgers, Pharmacology, Physiology & Neuroscience, Newark, United States
2Dept of Veteran Affairs, War Related Illness & Injury Study Center, East Orange, United States
Abstract
Increasing evidence is suggesting that concussions are a possible significant cause of long term cognitive and health problems among athletes. Despite this increasing evidence, there is a lack of data on the physiological response immediately following a head injury. The goal of this work was to determine if concussions cause impairment of cerebral blood flow regulation in the first few hours after injury and to determine if there is a sex difference in the response.
During several recreational rugby tournaments we recruited a total of 34 players. Of these players, 26 were recruited as controls (5 females) and 8 had suffered a concussion (3 females). All testing was performed on the field to assess cerebral blood flow using carotid ultrasonography, beat-by-beat blood pressure, and end-tidal CO2 while supine. Data was collected 131 ± 23 min following the head trauma.
Concussed players demonstrated significantly greater mean arterial pressures regardless of sex (Males - Ctrl 74 ± 10 vs Concussed 79 ± 14; Females Ctrl 67 ± 7 vs Concussed 82 ± 14 mmHg, P = 0.034). In contrast, internal carotid blood flow was no different in males (Ctrl 623 ± 173 vs Concussed 619 ± 214 mL/min), but tended to be lower in concussed females (Ctrl 619 ± 214 vs Concussed 448 ± 95 mL/min). This reduced cerebral blood flow was also associated with an increase in cerebrovascular resistance in females (Ctrl 0.12 ± 0.04 vs Concussed 0.18 ± 0.01 mmHg/(mL/min)) that did not occur in males (Ctrl 0.13 ± 0.04 vs Concussed 0.14 ± 0.05 mmHg/(mL/min)).
These data suggest that while both males and females had similar hypertensive responses following a sports related concussion, a tendency towards a greater decrease in cerebral flow when standing was found in the females. Thus further work is necessary to both understand the physiological response following concussion, but specifically with regards to sex differences.
This work was supported by the WRIISC within the Department of Veteran Affairs.
PS06-051
Poster Viewing Session VI
The expression of NP847 and Sox2 after TBI and its influence on NSCs
1Affiliated Hospital of Nantong University, Neurosurgery, Nantong, China
Abstract
The proliferation and differentiation of neural stem cells (NSCs) is important for neural regeneration after cerebral injury. Here, for the first time, we show that phosphorylated (p)-ser847-nNOS (NP847), rather than nNOS, may play a major role in NSC proliferation after TBI. Western blot results demonstrated that the expression of NP847 and Sox2 in the hippocampus is up-regulated after TBI, and they both peak 3 days after brain injury. In addition, an immunofluorescence experiment indicated that NP847 and Sox2 partly co-localize in the nuclei of NSCs after TBI. Further immunoprecipitation experiments found that NP847 and Sox2 can directly interact with each other in NSCs. Moreover, in an OGD model of NSCs, NP847 expression is decreased, which is followed by the down-regulation of Sox2. Interestingly, in this study, we did not observe changes in the expression of nNOS in the OGD model. Further research data suggest that the NP847-Sox2 complex may play a major role in NSCs through the Shh/Gli signaling pathway in a CaMKII-dependent manner after brain injury.
PS06-052
Poster Viewing Session VI
Effects of pyrroloquinoline quinone on WISP1 in traumatic brain injury
1Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong, China
Abstract
WISP1, as a member of the CCN4 protein family, has cell protective effects of promoting cell proliferation and inhibiting cell apoptosis. Traumatic brain injury model was established to study the role of WISP1 in nervous system in rat. Results showed WISP1 mRNA expression decreased at 3 d, increased at 5 d after TBI. WISP1 protein expression was similar to the mRNA expression of WISP1. Meanwhile, immunofluorescence was used to detect the cell location of WISP1, which demonstrated that there was little of co-location about WISP1 with GFAP, Iba1 respectively. However, WISP1 co-localized with NeuN partly. Double-labeling immunofluorescence about WISP1 with LC3 suggested that WISP1 was involved in autophagy. But there was little of co-location about WISP1 with Cleaved-Caspase3, which suggested that WISP1 was not directly relative to apoptosis. Subsequent study displayed that the protein expression trend of β-catenin was identical to that of WISP1 after TBI. Immunofluorescence in PC12 or SHSY5Y cells showed that WISP1 maily located in cytoplasm. WISP1 expression reduced obviously in SHSY5Y cells after being transfected with WISP1 si-RNA compared with negative control group. The effects of different concentrations or time of PQQ on the activity of PC12 and SHSY5Y cells were performed with CCK-8 assay, which suggested that PQQ had little influence on viability. Finally, Cell cycle was detected in SHSY5Y cells treated with 50 µM PQQ for 24 h after transfection with WISP1 si-RNA 72 h or 48 h. Results showed that there was no significant diversity. We thought that WISP1 plays a protective role after traumatic brain injury in rat and this effect may be relative to autophagy caused by traumatic brain injury.
PS06-053
Poster Viewing Session VI
Vascular reactivity changes of the intracortical blood vessels after juvenile traumatic brain injury
1INCIA UMR5287 CNRS, Bordeaux, France
Abstract
[Vascular reactivity with U46619 application]
PS06-054
Poster Viewing Session VI
D-dimer as a potential marker for structural damage to the brain parenchyma in traumatic brain injury
1National Hospital Organization Disaster Medical Center, Neurosurgery, Tokyo, Japan
Abstract
PS06-055
Poster Viewing Session VI
Evaluation of regional white matter volume reduction after diffuse axonal injury using voxel-based morphometry
1Kajiwara Hospital, Division of Internal Medicine, Tokyo, Japan
2Hashimoto Clinic Kyodo, Tokyo, Japan
3Jikei University School of Medicine, Department of Rehabilitation Medicine, Tokyo, Japan
Abstract
1. Uruma G, Hashimoto K, Abo M. A new method for evaluation of mild traumatic brain injury with neuropsychological impairment using statistical imaging analysis for Tc-ECD SPECT. Ann Nucl Med 2013; 27:187–202.
PS06-056
Poster Viewing Session VI
Evaluation of neutrophil elastase (NE) as an early prediction marker of trauma induced disseminated intra vascular coagulation (DIC)
1All India Institute of Medical Science, Delhi, India
Abstract
We aimed to investigate the prognostic significance of early measurement of neutrophil elastase in predicting DIC following injury.
On admission overt DIC was diagnosed in 16 patients out of whom 11 died and 5 regressed to non overt DIC. On admission 77 had non-overt DIC: 23 died, 5 progressed to overt DIC, 41 remained non-overt DIC and 8 returned to normal. On admission 7 had no DIC: 2 died and 4 progressed to non-overt DIC.
Admission day elastase levels were significantly associated with the progression of DIC on day 5, with ROC of 0.63, a cut off of 1342 ng/µl was established (sensitivity of 71.4; specificity 43.1). 21% developed sepsis, 31% coagulopathy, and mortality was 36%. Development of overt DIC significantly correlated with thrombocytopenia and coagulopathy (p = 0.02; < 0.001 respectively), but not with sepsis and mortality. Plasma neutrophil elastase levels significantly varied between patients who died within 24 hr following trauma and patients who died after ≥72 hrs(p = 0.05) and not with coagulopathy and sepsis (p = 0.19; 0.50 respectively).
PS06-057
Poster Viewing Session VI
Rolipram, a PDE-IV inhibitor protects against experimental Parkinsonism in mice
1Vivekananda Global University, Applied Biology, Jaipur, India
Abstract
PS06-058
Poster Viewing Session VI
Galectin-1-induced cognitive improvement, lower vascular and parenchymal amyloid deposition and immunomodulation in an animal model of Alzheimer's disease
1University of Buenos Aires, Department of Biological Chemistry, Buenos Aires, Argentina
2Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
Abstract
Alzheimer's disease (AD) is the leading cause of dementia in the elderly. Amyloid deposition and neuroinflammation are recognized hallmarks in AD, affecting mainly the brain cortex and hippocampus, both in patients and animal models. Galectin-1 (Gal1) -a glycan binding protein- is proposed to modulate several properties on immune and endothelial cells. Rabinovich's group (1) has previously reported a Gal1 neuroprotective role through deactivation of microglia in experimental autoimmune encephalitis, inducing an alternative phenotype. Here, we administered Gal1 or vehicle (i.p. 9 injections of 100ug/dose) during 3 weeks to 12-month-old PDAPPJ20 transgenic mice (Tg), or age-matched non-transgenic animals. Gal1 treatment improved the performance in the novel object location recognition test (p < 0.05). Congo red amyloid+ area in the hippocampus was decreased by 50% (p < 0.05) affecting mainly the dorsal hippocampus. Iba1+ microglial cells in the dentate gyrus exhibited less reactivity measured as soma size after Gal1 treatment (p < 0.05) while morphological score of microglial activation was significantly reduced, suggesting a modulatory effect on this cell population involved in amyloid clearance through phagocytosis. Moreover, the perivascular amyloid deposition decreased in treated Tg mice, visualized by tomato lectin labeling for microvasculature combined with Aβ immunofluorescence. In addition, we found that GFAP+ astrocytes surrounding amyloid plaques were Gal1+ in the hippocampus of Tg mice. We also generated PDAPPJ20/Gal1-/- animals, which exhibited an increased number of Iba1+ cells in the hippocampus. Our results showed a potential relevant role for Gal1 in this neurodegenerative disease at multiple levels, including cellular and cognitive aspects. Additional in vitro experiments are in progress to identify the associated mechanism of action of Gal1 modulating the neuroinflammatory status in the context of AD.
1- Starossom SC et al Immunity. 2012 Aug 24;37(2):249–63. doi: 10.1016/j.immuni.2012.05.023
PS06-061
Poster Viewing Session VI
Brain pericyte response in a mouse model of Huntington's disease
1Lund University, Deptartment of Clinical Sciences, Lund, Sweden
Abstract
1. Sagare et al, Pericyte loss influences Alzheimer-like neurodegeneration in mice, Nature Communications, 2013.
2. Gray et al, Striatal blood-brain barrier permeability in Parkinson's disease, J. of Cerebral Blood Flow and Metabolism, 2015.
3. Drouin-Ouellet et al, Cerebrovascular and blood-brain barrier impairments in Huntington's disease: Potential implications for its pathophysiology, Ann. Neurology, 2015.
4. Hsiao et al, Aberrant astrocytes impair vascular reactivity in Huntington disease, Ann. Neurology, 2015.
5. Armulik et al, Pericytes: developmental, physiological, and pathological perspectives, problems, and promises, Developmental cell, 2011.
PS06-062
Poster Viewing Session VI
Evaluation of CRISPr/SaCas9 induced gene knockdown in primary neurons and N27 cells
1Werner Siemens Imaging Center, Eberhard Karls University Tübingen, Department of Preclinical Imaging and Radiopharmacy, Tübingen, Germany
Abstract
Latest advance in genome engineering methodologies based on the CRISPR/Cas9 have enabled researchers to interrogate the mammalian DNA in a precise and simple manner in any organism of choice. To better understand the role of the presynaptic compartment in Parkinson's disease, characterized by a progressive loss of dopaminergic neurons in the substantia nigra (SN), we used the CRISPR/Cas9 system to selectively target the vesicular monoamine transporter 2 (slc18a2) and the tyrosine hydroxylase (th) genes, involved in the storage, release and synthesis of dopamine in rats.
To selectively target dopaminergic cells, we used two double-floxed adeno-associated viral (AAV) vectors expressing the SaCas9 enzyme and the guide RNA (sgRNA) scaffolds. We designed five sgRNAs for each target gene and one control targeting the lacZ gene and tested their knockdown efficiency in primary cortical neurons and in a dopaminergic N27 cell line using a third AAV expressing Cre-recombinase. The knockdown efficiency of the sgRNAs was assessed on DNA (surveyor) and protein (immunofluorescence) level, one week post transduction. Following the in vitro selection, the best guides were purified and injected together with the AAV-SaCas9 and AAV-Cre vectors at a concentration of 5.07×1014 gc/mL into the SN of naïve rats to determine possible toxicity effects. [11C]DTBZ PET experiments were performed 3 and 6weeks after AAV injections.
The in vitro data show, despite the low efficiency due to the three viral vector transduction, that two out of five sgRNAs for each target, were able to induce a selective knockdown of slc18a2 and th, if SaCas9, sgRNA and Cre were successfully co-expressed. In vivo PET experiments showed an initial decrease of the [11C]DTBZ BPND at the injected side at 3weeks, which returned to baseline levels 6weeks after injection. Next steps include the injection into DAT-Cre rats for a selective knockdown in dopaminergic neurons and functional imaging experiments.
PS06-063
Poster Viewing Session VI
Effects of L-DOPA and doxicycline administration on nociceptive responses in an animal model of Parkinson's disease
1University of Sao Paulo, Ribeirao Preto, Brazil
Abstract
Parkinson's disease (PD) is a neurodegenerative disorder caused by progressive loss of catecholaminergic neurons, especially in the substantia nigra compacta (SNc), resulting in the loss of dopaminergic transmission in the nigrostriatal pathway motor. The pain is often observed in patients with PD, and this symptom often precedes the diagnosis of the disease. Recently, it has been recognized that 83% of patients with PD show changes in pain sensitivity. Little is known underlying mechanisms and pathophysiology of pain in patients with Parkinson's disease, however, animal models that reproduce the pathophysiology of this condition has been frequently used for the evaluation of involvement in symptoms in PD The usual applied in PD therapy is purely symptomatic relieving primarily in the restoration of the nigrostriatal function with the use of drugs that stimulate dopamine neurotransmission. L-dihydroxyphenylalanine (L-DOPA) is the most common strategy in the treatment of PD. We investigated thermal and mechanical nociceptive responses of rats with 6OHDA lesion in dopaminergic neurons in the medial forebrain bundle (FPM - nigrostriatal pathway). Further, the same tests were performed on rats chronically treated with L-DOPA. In addition, we evaluated the anti-inflammatory effect of doxycycline, in the thermal nociception test, before and after development of dyskinesia induced by L-DOPA.The results showed decreased nociceptive thresholds, in von Frey and hotplate tests after 6OHDA lesion and a reversion of this condition though L-DOPA at 30 mg/kg concentration. Also, doxicycline evidenced an major effect for attenuate the hypersensitivity condition after 14 days of treatment. This study provides first evidence that 6OHDA administration increases nociceptive responses in rats and indicate the potential role of dopaminergic mechanisms in the 6OHDA-induced nociception, since it was attenuated by L-DOPA treatment. Additionaly, neuroinflammatory mechanisms can be involved in this process, since doxycycline was effective for decrease nociceptive responses.
PS06-064
Poster Viewing Session VI
Middle cerebral artery pulsatility index as predictor for cognitive impairment in hypertensive patients
1University of Indonesia, Neurology, Jakarta, Indonesia
2University of Indonesia, Community Health, Jakarta, Indonesia
Abstract
Keywords
Pulsatility index, middle cerebral artery, cognitive impairment, hypertension
Vicenzini E, Ricciardi MC, Altieri M, Puccinelli F, Bonaffni N, Di Piero V, et al. Cerebrovascular reactivity in degenerative and vascular dementia: a transcranial Doppler study. Eur Neurol 2007;58:84–9
PS06-065
Poster Viewing Session VI
Capillary flow control in an aged model of Alzheimer's disease
1Aarhus University Hospital / Institute of Clinical Medicine, CFIN, Aarhus, Denmark
2Aarhus University / Institute of Biomedicine, Aarhus, Denmark
Abstract
[Capillary hemodynamics in AD]
1. Ostergaard, L. et al. The capillary dysfunction hypothesis of Alzheimer's disease. Neurobiology of Aging
2. Gutiérrez-Jiménez, E. et al. Effect of electrical forepaw stimulation on capillary transit-time heterogeneity (CTH). JCBFM, (2016). doi:10.1177/0271678X16631560
PS06-066
Poster Viewing Session VI
Age drives the distortion of brain vascular, metabolic, and cognitive functions and the gut microbiome
1University of Kentucky, Lexington, United States
2University of Illinois at Chicago, Chicago, United States
Abstract
Age is the top risk factor for the development of numerous diseases including neurological disorders such as dementia. Previous research has demonstrated brain vascular defects preceding dementia symptoms. Further, an altered gut microbiota has also been linked to increasing one's risk for the development of neurological disorders. Specifically, metabolites produced by the gut microbiome can impact brain vascular function, such as by decreasing blood brain barrier permeability. Our objective was to examine the effects of the aging process on the gut and brain in Young and Old mice and how this collectively can affect neurological function. We hypothesized that brain function may be associated with the gut microbiome and over time, deleterious changes would be exhibited in both the brain and gut, effecting brain vascular, metabolic and cognitive functions. Young (5–6 mo.) and Old (18–20 mo.) male C57BL/6 mice were assigned to two groups (n = 19–20). Our multi-faceted approach included magnetic resonance imaging for measurement of cerebral blood flow (CBF), 16 S sequencing of the gut microbiome, brain metabolomics, blood brain barrier P-glycoprotein (P-gp) transport, and behavior testing. All statistical analyses were completed using GraphPad Prism with significance reached if p < 0.05. Our preliminary results found that Old mice had significantly decreased CBF compared to the Young mice. Further, the Young and Old mice also had significantly different microbial diversity along with alterations in certain bacterial taxa. Moreover, the Old mice had altered brain metabolomics, decreased P-gp activity, and performed worse on behavior tests. We conclude that the aging process may indeed alter the gut microbiome and the brain. This shows promise that by modulating the gut microbiome, brain health might be optimized to help prevent neurological disorders. However, a greater understanding of the mechanisms connecting the gut and brain need to be elucidated.
PS06-067
Poster Viewing Session VI
Effects of aging and 17β-estradiol on glucose transporter (GLUT3) and membrane functions in female rat brain: A therapeutic potential drug for Alzheimer's disease
1Jawaharlal Nehru University, School of Life Sciences, New Delhi, India
Abstract
Recently, there has been a growing interest in the action and functions of the ovarian steroid hormone estradiol, particularly on whether they are neuroprotective for such age related disease and neurodegenerative conditions like stroke, Parkinson's disease and Alzheimer's disease. The objective of this study was to observe the changes in activities of mitochondrial enzymes (monoamine oxidase (MAO), Na+K+ ATPase and Ca2+ATPase), membrane fluidity, DNA degradation, and glucose transporter 4 (GLUT3) expression in brains of female Wistar rats of 3 months (young), 12 months (adult) and 24 months (old) age groups, and to see whether these changes are restored to normal levels after exogenous administration of 17β-estradiol (E2) (0.1 µg/gm body weight for one month).
Controls animals received an equal volume of vehicle. After 30 days of hormone treatment, experimental animals of all the groups were sacrificed and brains were isolated for further study.
The results obtained in the present work revealed that normal aging was associated with significant decrease in the activity of Na+K+ATPase, Ca2+ATPase and membrane fluidity, GLUT3 levels in the brains of aging female rats, and an increase in DNA degradation and MAO activity. The present study showed that estradiol treatment significantly decreased DNA degradation, and MAO activity in brain of aging rats, and a reversal of Na+K+ATPase, Ca2+ATPase and GLUT3 levels was achieved.
It can therefore be concluded that estradiol's beneficial effects seemed to arise from its antilipofuscin, antioxidant, antilipidperoxidative effects, implying an overall anti-aging action. The results of this study will be useful for pharmacological modification of the aging process and applying new strategies for control of age related disorders.
PS06-068
Poster Viewing Session VI
Correlation of gait and balance disturbances with cognitive impairment in patients with stable and unstable angina in Kyrgyzstan
1Kyrgyz State Medical Academy, Neurology, Bishkek, Kyrgyzstan
Abstract
PS06-069
Poster Viewing Session VI
Effect of Syzygium cumini (jambolan) extract on spatial learning and memory of aging rats
1Indian Institute of M. Research, Biological Science, New Delhi, India
Abstract
PS06-070
Poster Viewing Session VI
Influence of sex on brain volume
1Faculty of Medicine - Kuwait University, Biomedical Engineering Unit - Department of Physiology, Jabriya, Kuwait
Abstract
It appears that there still remains to be no consensus on sex differences with regards to global brain gray matter volume and neurodegeneration. Understanding the influence of sex on global brain gray matter volume will ultimately provide a better understanding of any sex-biased neurodegeneration, and a closer understanding of any sex-biased cognitive and neurological diseases and conditions. Therefore, in this study we report on sex similarities and differences on global brain gray matter volume and the rate of decline in global brain gray matter volume across age, for both males and females, from 384 whole-brain magnetic resonance images.
PS06-071
Poster Viewing Session VI
Does the metabolic response to stroke explain the ‘obesity paradox'?
1University of Manchester, Faculty of Biology, Medicine and Health, Manchester, United Kingdom
2University of Birmingham, School of Biosciences, Birmingham, United Kingdom
Abstract
PS06-072
Poster Viewing Session VI
Hemisphere-dependent metabolic and hemodynamic reorganization of the brain in elderly patients with ischemic stroke
1D.F. Chebotarev Institute of Gerontology, National Academy of Medical Sciences, Kiev, Ukraine
Abstract
Duplex scanning of head and neck vessels was performed on the ultrasound device Sonoline Elegra (SIEMENS); magnetic-resonance spectroscopy of 1H nuclei was done on the tomograph 1.5 T Magnetom Vision Plus (SIEMENS).
PS06-073
Poster Viewing Session VI
Alzheimer's-induced alterations in cerebral energy metabolism measured with 2-photon fluorescence lifetime microscopy of intrinsic NADH
1Massachusetts General Hospital & Harvard Medical School, Martinos Center for Biomedical Imaging, Charlestown, United States
Abstract
PS06-074
Poster Viewing Session VI
Feasibility of opto-magnetic resonance spectroscopy at 9.4T
1University of Münster, TRIC, Münster, Germany
Abstract
1. Schmid et al. MRM, 2016
PS06-075
Poster Viewing Session VI
Improved cerebral energetics and ketone body metabolism in db/db mice
1University of Copenhagen, Dept. of Drug Design and Pharmacology, Copenhagen, Denmark
Abstract
PS06-076
Poster Viewing Session VI
Activity-induced cellular lactate changes in the brain
1University of Zurich, Institute of Pharmacology and Toxicology, Zürich, Switzerland
2University of Zurich & ETH, Neuroscience Center Zürich, Zürich, Switzerland
3Centro de Estudios Cientificos, Valdivia, Chile
Abstract
Lactate elevations in the brain upon activation have been described several decades ago and were primarily taken as evidence for a mismatch between glycolysis and respiration. However, to completely establish the full biological significance of activity-induced cerebral lactate elevations methods that resolve events on a cellular level are necessary. The advent of the new genetically encoded lactate biosensor Laconic, which can be expressed in vivo in a cell-specific manner using respective promoters and adeno-associated viruses, allows the observation of lactate levels in single cells. In combination with two-photon laser scanning microsopy we examined lactate concentrations in astrocytes and neurons in the cerebral cortex of anesthetized mice upon increased activity. With the onset of intracortical microelectrode stimulation transient lactate increases in neurons and astrocytes were observed. After cessation of the 1-min stimulation period lactate levels did not return to baseline immediately. In experiments, where we applied the lactate dehydrogenase blocker oxamate the stimulation-induced increases in lactate concentration diminished significantly in both astrocytes and neurons by 50%. In a second cohort of mice, we investigated the dynamics of the upstream substrate glucose during the same stimulation protocol using the genetically encoded glucose sensor FLII12Pglu600µΔ6. Interestingly, glucose levels exhibited stimulation-induced decreases only in astrocytes whereas neuronal levels remained stable.
Previously observed cerebral lactate elevations are now for the first time assigned to astrocytes and neurons. Based on our results, lactate seems mainly be derived from cerebral metabolism. However, future experiments should be designed to answer the questions about the exact cellular origin of the lactate increases.
PS06-077
Poster Viewing Session VI
Masticatory muscle metabolic dysfunction and neuronal excitability induced by unpredictable chronic stress in rats
1University of Sao Paulo, Ribeirao Preto, Brazil
Abstract
The patient has dental losses reveals an occlusal collapse influencing stomatognathic functions. Although stress be involved in the pathogenesis of chronic diseases and enable the masticatory muscle pain in patients, it is still not understood the mechanism by which muscle adapts to psychological and physiological stress in orofacial muscle dysfunction and which neural pathways are involved in this process. This study investigates the effect of chronic stress associated with unilateral extraction on the medial pterygoid muscle of rats and neural activity of brain areas and the influence of pre -treatment with diazepam. Wistar rats were divided in with or without stress and diazepam administration or your vehicle. The rats were euthanized to obtain the medial pterygoid muscle and brain and immunohistochemical analysis for reactive oxygen species (ROS) and c-fos and fos B were performed. The results indicate an increase of ROS in groups subjected to stress and extraction, together or separately (Two Way ANOVA, Student-Newman-Keuls, P < 0.01). The group subjected to stress and treated with vehicle (63.8 ± 1.5) was different from the group treated with benzodiazepines (51.6 ± 2.46) (Student-Newman-Keuls, P < 0.05), where the treatment for 10 days, was effective in reducing ROS in the muscles of animals subjected to chronic stress. Quantitative analysis indicates increased neuronal activity in amygdala, hippocampus and trigeminal nucleus after tooth extraction and stress protocol. Diazepam reduced neuronal labeling during the stress in the limbic system, and in trigeminal nuclei. This study indicates that stress were able to increase ROS in the medial pterygoid muscle and FOS in brain regions and shows reversion of this situation through benzodiazepine therapy. Use of this treatment protocol can be effective in the attenuation of pathological situation by stressors in masticatory muscles.
PS06-078
Poster Viewing Session VI
Signaling in brain via cAMP is decreased in unmedicated depressed patients and normalizes with drug treatment
1NIMH, DHHS, Bethesda, United States
Abstract
PS06-079
Poster Viewing Session VI
The effects of progesterone administration in patients with diffuse axonal injury
1Physiology Research Center, Institute of Neuropharmacology, Afzalipour School of Medicine, Kerman University of Medical Sciences, Kerman, Iran, Islamic Republic of
2Endocrinology and Metabolism Research Center, Institute of Basic and Clinical Physiology Sciences, Kerman University of Medical Sciences, Kerman, Iran, Islamic Republic of
3Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran, Islamic Republic of
4Kerman University of Medical Sciences, Afzalipour School of Medical Sciences, Dept. of Neurosurgery, Kerman, Iran, Islamic Republic of
Abstract
PS06-080
Poster Viewing Session VI
Temozolomide arrests glioma growth and normalizes intratumoral extracellular pH
1Yale School of Medicine, Radiology and Biomedical Imaging, New Haven, United States
2Yale School of Medicine, Biomedical Engineering, New Haven, United States
3Henry Ford Hospital, Neurology, Detroit, United States
Abstract
An acidic extracellular pH (pHe) of gliomas promotes tumor growth and builds resistance to therapy. Given evidence that acidic pHe beyond the tumor core indicates infiltration, we hypothesized that imaging the intratumoral pHe in relation to the peritumoral pHe can provide a novel readout of the changing tumor microenvironment with therapy. We used Biosensor Imaging of Redundant Deviation in Shifts (BIRDS), which utilizes shifts of non-exchangeable protons from macrocyclic chelates (e.g., 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetrakis(methylene phosphonate) or DOTP8-) complexed with paramagnetic thulium (Tm3+), to generate pHe maps in rat brains bearing U251 tumors. Upon TmDOTP5- infusion, MRI identified tumor boundary and BIRDS imaged the pHe gradient between intratumoral and peritumoral regions (delta pHe). Approximately two weeks after implantation of U251 glioma cells, animals were either treated with temozolomide (50 mg/kg) or were left untreated. Reduced proliferation (by Ki-67; p < 0.03) and induction of apoptosis (by cleaved Caspase-3; p < 0.001) were observed in treated rats compared to untreated rats. Tumor growth, measured at approximately three weeks (after glioma implantation), was inhibited in treated rats compared to untreated rats (p < 0.03). The delta pHe was significantly higher in untreated rats compared to treated rats (p < 0.002). These results suggest that temozolomide therapy, which induces apoptosis, hinders tumor growth and proliferation while at the same time normalizes intratumoral pHe. In summary, BIRDS can be used to map the delta pHe in glioma treatments (e.g., pHe and pO2 targeted drugs) to provide a metabolic readout of the tumor microenvironment.
PS06-081
Poster Viewing Session VI
The structural atrophy is associated with CSF neurofilament light chain in a transgenic rat model of Alzheimer's disease
1McGill University, Integrated Program in Neuroscience, Montréal, Canada
2Douglas Mental Health Institute, Verdun, Canada
3Federal University of Rio Grande do Sul - UFRGS, Biochemistry, Porto Alegre, Brazil
4The Sahlgrenska Academy at University of Gothenburg, Psychiatry and Neurochemistry, Gothenburg, Sweden
5McGill University, Montréal, Canada
6McGill University, Pharmacology, Montréal, Canada
Abstract
1. Journal of Alzheimer's Disease 20.1 (2010): 113–126.
2. Recent Advances and the Future Generation of Neuroinformatics Infrastructure (2015): 227.
3. Clinical Chemistry and Laboratory Medicine (2016).
4. Frontiers in Neuroinformatics 10 (2016): 20.
PS06-082
Poster Viewing Session VI
T-cell stimulation in human stroke
1August Pi i Sunyer Biomedical Research Institute (IDIBAPS), Barcelona, Spain
2Hospital Clinic Barcelona, Functional Unit of Cerebrovascular Diseases, Barcelona, Spain
3University of Texas Southwestern Medical Center, Departments of Neurology and Neurotherapeutics, and Immunology, Dallas, United States
4Instituto de Investigaciones Biomedicas de Barcelona IIBB-CSIC, Department of Brain Ischemia and Neurodegeneration, Barcelona, Spain
Abstract
PS06-083
Poster Viewing Session VI
Brain-targeting adaptive immune responses in extracorporeal membrane oxygenation-treated patients
1UT Southwestern Medical Center, Neurology and Neurotherapeutics, Dallas, United States
Abstract
PS06-084
Poster Viewing Session VI
Impairment of vasopressin secretion in sepsis survivor rats
1University of São Paulo, Department of Neurosciences and Behavioral Sciences of Ribeirão Preto Medical School, Ribeirão Preto, Brazil
2University of São Paulo, Department of Clinical Analysis, Toxicology and Bromatology, School of Pharmaceutical Sciences of Ribeirão Preto, Ribeirão Preto, Brazil
3University of São Paulo, Department of Pharmacology, Ribeirão Preto Medical School, Ribeirão Preto, Brazil
4Federal Rural University of Rio de Janeiro, Department of Physiological Sciences, Institute of Biology, Seropédica, Brazil
5University of São Paulo, Department of Morphology, Physiology and Basic Pathology, School of Dentistry of Ribeirão Preto, Ribeirão Preto, Brazil
Abstract
Siami S, Polito A, Porcher R, Hissem T, Blanchard A, Boucly C, et al. Thirst perception and osmoregulation of vasopressin secretion are altered during recovery from septic shock. PLoS One. 2013;8(11):e80190.
Siami S, Bailly-Salin J, Polito A, Porcher R, Blanchard A, Haymann JP, et al. Osmoregulation of vasopressin secretion is altered in the postacute phase of septic shock. Crit Care Med. 2010;38(10):1962–9.
PS06-085
Poster Viewing Session VI
Defining mitochondrial biomarkers and function using magnetic resonance spectroscopy at 14.1 Tesla in a mouse model of mood disorders
1Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Functional and Metabolic Imaging (LIFMET), Lausanne, Switzerland
2Ecole Polytechnique Federale de Lausanne (EPFL), Center for Biomedical Imaging (CIBM), Lausanne, Switzerland
3Centre Hospitalier Universitaire Vaudois (CHUV), Center for Psychiatric Neuroscience (CNP), Lausanne, Switzerland
4University of Geneva, Department of Radiology, Geneva, Switzerland
5University of Lausanne, Department of Radiology, Lausanne, Switzerland
Abstract
In vivo magnetic resonance imaging(MRI) and spectroscopy(MRS) are two non-invasive techniques of choice for investigating and monitoring brain metabolic and biological changes related to mitochondrial function and health. Mitochondria have been associated with many brain disorders and, among them, mood disorders (Chaturvedi & Flint Beal, 2013). Defining and understanding mitochondrial MRI/MRS biomarkers related to mood disorders could be an important contribution for a better endophenotypic characterization of these psychiatric illnesses.
In this study we have investigated the MRI/MRS profile of a new mouse model of mood disorders lacking an important brain plasticity gene, Crtc1(CREB-regulated transcriptional coactivator 1). (Breuillaud et al., 2009; Breuillaud et al., 2012).
Metabolic and volumetric profile alterations were determined with T2-weighted MRI together with 1H-MRS of prefrontal cortex(PFC) and dorsal hippocampus(HDors). Results indicated an age-dependent alteration of glutamate and GABA levels in Crtc1 KO mice PFC together with a constant reduction in phosphocreatine(PCr) energy metabolites in the dorsal hippocampus (PFC: Glu(−12 ± 3%), GABA(−26 ± 11%); HDors: PCr(−20 ± 8%)). qPCR experiments revealed no changes in electron transport chain(ETC) gene expression but increased creatine kinase(CKMt and CKB) levels in the dentate gyrus of KO mice, confirming neuroenergetic deficiency in dorsal hippocampus. Mitochondria quantification using mtDNA copy number revealed a specific reduction of mitochondrial mass in the dentate gyrus, which could explain the observed energetic dysfunction. Finally, preliminary 1H[13C]-MRS results upon infusion of [U-13C]glucose suggested metabolic differences in the dorsal hippocampus, where enrichment curves indicate a reduced glucose uptake together with an increased TCA cycle rate in KO animals. Together, these results suggest that CRTC1 might be an essential regulator of brain energy metabolism in the mouse dorsal hippocampus. Further investigations will aim at clarifying the mitochondrial failure of these mice and monitor its evolution with its associated MRI/MRS profile.
PS06-086
Poster Viewing Session VI
Activation-induced lactate changes in the human brain by J-edited 1H-MRS
1Yale University, New Haven, United States
Abstract
PS06-087
Poster Viewing Session VI
Neurovascular niche: effects of Angiotensin II
1Tufts Medical Center and Tufts University School of Medicine, Neurology, Boston, United States
2Temple University School of Medicine, Neurology, Philadelphia, United States
Abstract
In adult brain, neuronal stem cells (NSC) are located in the neurovascular niche therefore, vascular cells play an important role in creating a healthy environment for adult neurogenesis. Several laboratories including ours have demonstrated that Angiotensin II (AngII)-induced hypertension affects numerous vascular functions by causing oxidative stress, vascular inflammation and endothelial dysfunction. Further, the available evidence suggests that blood-brain barrier (BBB) deregulation is an indirect consequence of cerebrovascular inflammation. Of these, AngII effect on BBB dysfunction has been reported, and is implicated in the pathogenesis of stroke, small vessel disease, vascular dementia and Alzheimer's disease. In this regard, miRNAs emerged as key players in the development of vascular and neurodegenerative diseases. In here, we studied the effects of AngII on adult NSC and brain endothelial cell (BEC) miRNAs regulation and their interaction focusing on a specific miRNAs that were selected due to their role in other vascular systems. We used primary mouse NSC and BEC culture model to study the effects of AngII on miR-15, -34a, -155 and -let7 expression using qPCR. AngII 100 nm induced expression of miR-15 in both neurospheres and BEC by 2 and 2.5-fold respectively after one hr. miR-34 a expression was induced by 3.5-fold in neurospheres and by 3-fold in BEC in 24-hr. Mir-155 expression was elevated in neurospheres by 2-fold and in BEC by 3-fold after 45-min. miR-let7 was increased in neurospheres and BEC by 4-fold in 15 min, and remained induced in EC for one hr. These miRNAs expression changes were accompanied by increased protein expression of C/EBPb, pCREB, and p38MAPK. However, Ets1 expression was downregulated in both neurospheres and BEC. These results indicate that AngII has major effects on NSC and BEC through deregulating miRNAs and protein levels involved in this phenomenon. Further studies are needed to explore the mechanisms involved.
PS06-089
Poster Viewing Session VI
Interleukin-6 levels in cerebrospinal fluid and plasma in patients with severe spontaneous subarachnoid hemorrhage
1Uppsala University, Neurosciences, Uppsala, Sweden
2Karolinska Institutet, Neurosciences, Stockholm, Sweden
Abstract
There is substantial evidence that inflammatory processes play a key role in the pathophysiology of spontaneous subarachnoid hemorrhage (SAH) [1]. This study evaluated the inflammatory response in the acute phase after SAH and researched whether different temporal patterns of systemic and intrathecal inflammation could be identified. The intensity of the inflammatory response was also assessed in different clinical subgroups.
Forty four patients with severe SAH were included (median WFNS score = 4, median Fisher scale = 4 on admission). Cerebrospinal fluid (CSF) and blood samples were collected at days 1, 4 and 10 after ictus. Interleukin-6 (IL-6) was analysed by a routine monoclonal antibody-based method (Roche CobasE 602; reference interval for plasma < 7.0 ng/L; for CSF not available). Median IL-6 values for each day were calculated. Day 4 IL-6 values were considered indicator of the intensity of inflammatory response and compared in dichotomised subgroups (age, sex, WFNS score, Fisher scale, vasospasm, CNS infection, systemic infection).
Median IL-6 concentrations for day 1, 4 and 10 in CSF were 876.5, 3361 and 1567 ng/L while in plasma 26, 27.5 and 15.9 ng/L, respectively. The most prominent difference in day 4 IL-6 concentrations in CSF could be seen in WFNS score-based subgroups (1–3 vs 4–5 = 1158.5 vs 5538 ng/L, p = 0.056). No significant differences could be observed in any other subgroup. Patients with systemic infection had significantly higher IL-6 concentrations in plasma (31 vs 16.05 ng/L, p = 0.028).
A distinctly different inflammatory pattern both regarding its development over time and its intensity was seen intrathecally compared to the systemic circulation, indicating endogenous cytokine production within the CNS. Significant difference in the intensity of the inflammatory response in plasma was seen in cases of systemic infection but in no other subgroup, likely due to the homogeneity of the patient cohort.
1. Miller BA, Biomed Research International, 2014, 384342
PS06-090
Poster Viewing Session VI
Metabolic changes in developing brain due to chronic liver disease: an in vivo longitudinal and multiparametric study using 31P-MRS (magnetic resonance spectroscopy),31P-Magnetization transfer and 1H-MRS
1Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Functional and Metabolic Imaging (LIFMET), Lausanne, Switzerland
2Medical University of Vienna, High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Vienna, Austria
3Ecole Polytechnique Federale de Lausanne (EPFL), Centre d'Imagerie Biomedicale (CIBM), Lausanne, Switzerland
Abstract
Our aim was to perform a multi-parametric in vivo and longitudinal study to assess brain metabolism in developing brain during CLD by combining static and kinetic high field 31P-MRS and 1H-MRS.
tNAD(NAD++NADH) pool did not change, however, the observed fluctuating ratio of NAD+/NADH indicates instable cellular redox state, in agreement with ascorbate and GSH decrease and lactate increase measured using 1H-MRS.
In addition, BDLs had markedly altered phospholipid metabolism (decreasing PDE, leading to increased PME/PDE ratio).
These preliminary results have to be validated on larger group of animals.
Oxidative stress may be responsible for varying cellular redox state as well as alterations in kATP→PCr. CK is susceptible to oxidative stress, resulting either in its impaired functions or compensatory up-regulation of its gene expression.
Phospholipid metabolism could be also altered due to increased oxidative stress by membrane lipid peroxidation. These changes in phospholipid metabolism seem to be characteristic for developing brain during CLD since it was not observed in adults with CLD.
PS06-091
Poster Viewing Session VI
Evaluation of hemodynamic impairments in unilateral high-grade carotid artery stenosis patients and healthy age-matched participants
1Technical University of Munich, Department of Neuroradiology, Munich, Germany
2Technical University of Munich, TUM Neuroimaging Center, Munich, Germany
3Helmholtz-Zentrum Dresden-Rossendorf, PET Center, Institute of Radiopharmaceutical Cancer Research, Dresden, Germany
4Technical University of Munich, Clinic for Neurology, Munich, Germany
Abstract
We propose a combination of three different MR-based methods, accounting for cerebrovascular reactivity (CVR) by breathhold-fMRI (voxelsize 3×3×3mm3, 38 slices, TE/TR = 30 ms/1200ms, acq.time = 5:48 min), CBF by pCASL (3D-readout, voxelsize 2.7×2.8×6mm3, 16 slices, TE/TR = 7.4 ms/4403ms, label duration = 1800 ms, PLD = 2000 ms, acq.time 5:43 min) and relative oxygen extraction fraction (rOEF) by a multi-parametric quantitative-BOLD approach3 (voxelsize 2×2×3mm3, 30 slices). For each participant, individual masks of watershed areas were defined for both hemispheres in grey-matter and mean values of all three modalities were compared.
1: Petty et al. Stroke, 30 (1999): 2513–2516.
2: Vakil et al. Radiology 266(3) (2013): 879–886.
3: Hirsch et al. NMR Biomed, 27 (2014): 853–862.
4: Bouvier et al. HBM 36(2) (2015) 695–706.
PS06-092
Poster Viewing Session VI
TOR drives fibrillar amyloid-β accumulation and cerebrovascular dysfunction in the Tg2576 model of Alzheimer's disease
1Univeristy of Texas Health Science Center at San Antonio, Barshop Institute, Cellular and Integrative Physiology, San Antonio, United States
Abstract
Cerebral amyloid angiopathy (CAA), characterized by neurovascular fibrillar amyloid β (Aβ) accumulation, is present in up to 90% of patients with Alzheimer's disease (AD). To determine the role of mTOR in the pathogenesis of CAA and associated cerebrovascular dysfunction, we used intravital two-photon microscopy though an intact skull to measure fibrillar Aβ lesions as well as vascular reactivity in control- and rapamycin-treated 18–19 month-old Tg2576 mice. Further postmortem histological analysis and immunofluorescent confocal microscopy was performed to assess the consequences of fibrillar Aβ vascular deposition on BBB integrity and cerebrovascular damage in the same mice that were used for in vivo optical microscopy.
The present studies demonstrate that mTOR attenuation by rapamycin reduces the quantity and density of brain vascular Aβ lesions, preserves blood brain barrier (BBB) integrity and maintains brain vascular reactivity even in the presence of high vascular fibrillar Aβ load in Tg2576 mice, a mouse model of AD that recapitulates AD-associated CAA. Further, the maintenance of BBB integrity by chronic mTOR attenuation in Tg2576 transgenic mice reduced the number of cerebral microhemorrhages associated with CAA-like lesions. Importantly, the restoration of cerebrovascular integrity and reactivity by mTOR attenuation was associated with mitigated contextual memory deficits in the same Tg2576 mice that were used for in vivo optical imaging. These data, together with our recent published studies in the APP(J20) AD model, indicate that mTOR contributes to the development of CAA-like lesions, BBB breakdown, Aβ-induced cerebrovascular dysfunction, and cognitive deterioration in various independent mouse models of AD. Thus, mTOR inhibitors such as rapamycin, an FDA-approved drug, may have promise to treat AD and potentially other dementias that have vascular dysfunction as a common etiology.
PS06-093
Poster Viewing Session VI
One-sided hypoperfusion is associated with contralateral attention deficits in asymptomatic high-grade carotid-stenosis patients
1Technische Universität München (TUM), Neuroradiology, Munich, Germany
2TUM Neuroimaging Center (TUM-NIC), Munich, Germany
3Technische Universität München (TUM), Clinic for Neurology, Munich, Germany
Abstract
1. Landgraff NC et al. Journal of neurology 2010;257:982–91.
2. Alsop DC et al. Magnetic resonance in medicine 2015;73:102–16.
3. Bundesen C. Psychological review 1990;97:523–47.
PS06-095
Poster Viewing Session VI
Quantification of GABA, glutamate and glutamine in a single measurement at 3T using GABA-optimized MEGA-PRESS
1University of Manchester, Centre for Imaging Science and Manchester Academic Health Sciences Centre, Manchester, United Kingdom
2University of Manchester, Division of Neuroscience and Experimental Psychology and Manchester Academic Health Sciences Centre, Manchester, United Kingdom
Abstract
[Fig.1]
1. P.G.Mullins, el al.Neuroimage.2013;86.
2. V.Govindaraju et al.NMR Biomed.2000;13.
PS06-096
Poster Viewing Session VI
Estimating subject numbers for study designs using functional GABA spectroscopy in human brain
1University of Manchester, Centre for Imaging Science and Manchester Academic Health Sciences Centre, Manchester, United Kingdom
2University of Manchester, Division of Neuroscience and Experimental Psychology and Manchester Academic Health Sciences Centre, Manchester, United Kingdom
Abstract
1. Stagg et al, Neuroimage.2014(86):19–27.
2. Lin et al, J Cereb Blood Flow Metab.2012(32.8):1484–1495.
3. Shungu et al, NMR Biomed.2016(29):932–942.
PS06-097
Poster Viewing Session VI
Brain astroglial reaction in mild hepatic encephalopathy: experimental evidence in the cirrhotic rat
1Cadi Ayyad University, Marrakech, Morocco
Abstract
Hepatic encephalopathy (HE) is a neuropsychiatric disorder that occurs in both acute and chronic liver failure. However, the pathomechanisms of the disease remains obscure. Neuopathological studies have demonstrated a primary gliopathy in humans as well as in animal models of chronic and acute liver failure. Here, we have investigated in an animal model of mild HE: the bile duct ligated rat (BDL) at the cirrhotic stage (4 weeks after surgery), the expression of the key marker of mature astrocytes; the glial fibrillary acidic protein (GFAP) in different brain areas such as: Substantia nigra pars compacta (SNc), Ventral tegmental area (VTA), hippocampus, dorsal striatum and brain cortex by means of immunohistochemistry. The immunohistochemical study showed, in BDL compared to the operated controls (shams), a diminished astrocyte reactivity corresponding to a loss of GFAP expression within SNc, VTA, hippocampus and dorsal striatum (p < 0.05), whereas in the brain cortex astrocytes appeared strongly immunoreactive with increased GFAP expression (p < 0.05) as compared to shams. Our finding demonstrated differential astroglial responses which depend to the specificity of the area investigated and its particular neuronal neighboring environment, and could have possible outcomes on the diverse neuronal functions especially those observed during the different episodes of hepatic encephalopathy.
PS06-098
Poster Viewing Session VI
Metabolite concentration changes during increase of the BOLD signal in the human visual cortex: a functional magnetic resonance spectroscopy study at 7T
1Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Functional and Metabolic Imaging, Lausanne, Switzerland
2Ecole Polytechnique Federale de Lausanne (EPFL), Center for Biomedical Imaging, Lausanne, Switzerland
3Spinoza Centre for Neuroimaging, Amsterdam, Netherlands
4University of Lausanne, Department of Radiology, Lausanne, Switzerland
5University of Geneva, Department of Radiology, Geneva, Switzerland
Abstract
[Figure1]
1) Xin et al., 2012
2) Gruetter and Tkac, 2000
3) Provencher, 1993
4) Schaller et al., 2012
PS06-099
Poster Viewing Session VI
Effect of body position on cerebrovascular reactivity in healthy men and women
1Rutgers University, Pharmacology, Physiology & Neuroscience, Newark, United States
2Veterans Affairs New Jersey Health Care System, War Related Illness and Injury Study Center, East Orange, United States
Abstract
Cerebrovascular reactivity represents the ability to dilate the cerebral vessels to metabolic stimuli such as CO2. However, it is unknown if reactivity is altered between supine, seated and standing positions and if the response is different between men and women. Five healthy men (range 18–47 years) and four healthy women (range 23–54 years) were asked to breathe room air, a hypercapnic mixture of 5% CO2, 21% O2, balance nitrogen, and to mildly hyperventilate (hypocapnia) for two minutes each (resulting in ∼±10 mmHg change), while continuous measurements of blood pressure, heart rate, cerebral blood flow velocity of the middle cerebral artery, and end-tidal CO2 were taken. Results show that the overall reactivity across both hypercapnia and hypocapnica ranges were not significantly different between the body positions (p = 0.141) or between the sexes (p = 0.193; Supine: men = 3.4 ± 0.6%/mmHg vs women = 2.9 ± 0.5%/mmHg; Seated: men = 2.7 ± 0.6%/mmHg vs women = 2.6 ± 0.2%/mmHg; Standing: men = 3.1 ± 0.4%/mmHg vs women = 2.7 ± 0.8%/mmHg). When examining the dilatory response during hypercapnia, there was no significant difference between the body positions (p = 0.217) or between the sexes (p = 0.574; Supine: men = 3.2 ± 1.5% vs women = 3.3 ± 1.3%; Seated: men = 2.4 ± 0.7% vs women = 3.0 ± 1.3%; Standing: men = 2.6 ± 0.8% vs women = 3.1 ± 0.9%). When measuring the vasoconstrictive response during hypocapnia, there was no significant difference across body positions (p = 0.271), but there was a trend towards significantly greater vasoconstriction in men compared to women (p = 0.088; Supine: men = 3.8 ± 1.0%/mmHg vs women = 2.9 ± 0.9%/mmHg; Seated: men = 3.3 ± 1.5%/mmHg vs women = 2.1 ± 1%/mmHg; Standing: men = 3.2 ± 0.4%/mmHg vs women = 2.3 ± 0.8%/mmHg). In addition, there was a large effect for this trend (partial eta squared = 0.359). Further participants are needed to assess whether there are differences in reactivity across the body positions or between the sexes. However, if the trend continues with additional participants, these results may indicate an enhanced vasoconstrictive response in men compared to women.
PS06-100
Poster Viewing Session VI
Postnatal development of neurovascular coupling
1Massachusetts General Hospital & Harvard Medical School, Internal Medicine, Boston, United States
2Columbia University Medical Center, Neurobiology and Behavior, New York, United States
3Columbia University, Biomedical Engineering, New York, United States
Abstract
In this new study, we aimed to determine the neural activity underlying developmental differences in hemodynamics and define the resulting oxygenation dynamics (Kozberg, 2016).
Localized neural activity (both spontaneous and in response to stimulation) in early postnatal mice led to minimal increases in local blood flow. These hemodynamic responses were insufficient to meet the energy demands of activated brain regions, leading to relative hypoxias in active regions that were verified via metabolic imaging.
PS06-101
Poster Viewing Session VI
Selective knockout of microglial Na+/H+ exchanger isoform 1 in mice does not reduce acute stroke brain injury but improves neuronal function recovery
1University of Pittsburgh, Department of Neurology, Pittsburgh, United States
2Tianjin University of Traditional Chinese Medicine, Tianjin State Key Laboratory of Modern Chinese Medicine, Tianjin, China
3University of Cincinnati, Department of Molecular Genetics, Biochemistry and Microbiology, Cincinnati, United States
4New York University School of Medicine, Molecular Neurobiology Program, Skirball Institute, Dept. of Physiology and Neuroscience, New York, United States
5Veterans Affairs Pittsburgh Health Care System, Geriatric Research, Educational and Clinical Center, Pittsburgh, United States
Abstract
Na+/H+ exchanger isoform-1 (NHE1) is ubiquitously expressed in all cell types in the central nervous system (CNS) and plays a role in ischemic brain damage. In this study, CamKIICre+/-;Nhe1flox/flox and Cx3cr1CreER+/-; Nhe1flox/flox mice were established to evaluate the roles of NHE1 in neurons and microglia in ischemic brain damage. In the case of Cx3cr1CreER+/-;Nhe1flox/flox mice, either corn oil (3.75 ml/kg body weight/day) or tamoxifen (Tam, 75 mg/kg/day, i.p., for 5 days) was given to mice at P30–34. Ischemic stroke was induced at P65–75 with 60 min of transient middle cerebral artery occlusion (tMCAO). Compared to CamKIICre+/- control mice, CamKIICre+/-; Nhe1flox/flox mice showed a significant reduction in infarct volume at 48 h post-tMCAO, and improvements in neurological function 1–14 days after stroke (p < 0.05). In contrast, there were no decreases in ischemic infarct volume detected in the Tam-treated Cx3cr1CreER+/-;Nhe1flox/flox mice at 48 h after ischemic stroke; but these mice recovered significantly faster in their neurological function during 1–14 days after tMCAO (p < 0.05). They also exhibited a significantly higher survival rate during 1–14 days after ischemia. The flow cytometry analysis revealed that selective deletion of microglial NHE1 in the Cx3cr1CreER+/-;Nhe1flox/flox mice reduced CD11b+/CD45low-medium microglial population in ischemic brains at 3 days post-ischemia, and increased populations of microglia with the Ym1 and CD206 anti-inflammatory phenotype, and decreased pro-inflammatory CD16/32 and CD86 expression. In comparison, selective deletion of neuronal NHE1 in the CamKIICre+/-;Nhe1flox/flox mice showed no differences in the CD11b+/CD45low-medium microglial population from the control mice during 1–14 days after ischemic stroke. These findings strongly suggest that microglial NHE1 and neuronal NHE1 play differential roles in acute ischemic brain injury formation and post-stroke recovery. Especially, microglia-mediated inflammation is involved in the brain tissue repair and functional plasticity.
This project is supported by NIH R01 NS048216 (D. Sun), AHA Postdoctoral Fellowship 17POST32440002 (S. Song).