Experimental Biology and Medicine

In this study, we investigated the effect of diet supplementation with sodium butyrate (5% w/w), a short-chain fatty acid produced by the intestinal microbiota, on metabolic parameters, body adiposity, hepatic and pancreatic lipid accumulation, beta cell function/mass as well as on the structure and function of the tight junction-mediated intestinal epithelial barrier in both normal and obese/prediabetic C57 mice fed a regular (control) or high-fat diet for 60 days, respectively. Butyrate treatment significantly inhibited all the high-fat-induced metabolic dysfunctions evaluated, i.e. significantly reduced the weight gain and body adiposity as well as the insulin resistant state, hyperglycemia and hyperinsulinemia, without changing food intake. In addition, high-fat-fed mice treated with this short-chain fatty acid displayed no compensatory hyperplasia of pancreatic beta cells nor marked hepatic steatosis as seen in prediabetic mice after high-fat diet only. Isolated pancreatic islets from high-fat-fed mice treated with butyrate showed improvement of the insulin secretion, which was associated with a significant decrease in lipid accumulation within the pancreas. Butyrate enhanced the intestinal epithelial barrier, as revealed by the FITC-Dextran permeability assay, which was accompanied by a significant increase in the junctional content of the tight junction-associated claudin-1 in intestinal epithelia of jejunum, ileum, and colon of both control and high-fat mice. In conclusion, our results showed that diet supplementation with butyrate inhibits the deleterious effects of high-fat diet intake on metabolic parameters and structure/function of several tissues/organs associated with type 2 diabetes mellitus in a mouse model, suggesting a potential use of this short-chain fatty acid in the treatment of this endocrine-metabolic disorder.

Human cytomegalovirus (HCMV) dormant infection can alter the expression of the hosts’ microRNAs (miRNAs) and impact on the regulation of target genes. To investigate the differentially expressed miRNAs induced by HCMV in human glioma U251 cells, a comprehensive miRNA screen was performed. As a result, 19 up-regulated and 14 down-regulated miRNAs were determined. Of these, hsa-miR-27b (miR-27b) attracted our attention. MiR-27b levels in U251 cells increased 7.70-fold, 8.64-fold, and 4.78-fold, respectively, post 24 h, 48 h, and 72 h HCMV infection, compared to those in the mimic-infected cells, and this up-regulation was further confirmed by quantitative RT-PCR. The bioinformatic analyses show that miR-27b targets engrailed-2 (EN2) gene; however, the effect of miR-27b on EN2 is rarely encountered. In this study, we initially conducted dual luciferase assay to validate the target function of miR-27b on EN2. The results manifested that EN2 is a novel target of miR-27b, which could directly target the 3′ untranslated region (3′-UTR) of the gene. We further found that the miR-27b transfected glioma U251 cells exhibited longer cell bodies with more synapses and multiple-angle shapes; moreover, Western blot detection revealed that the EN2 protein levels in these cells were significantly low. In conclusion, our study originally reports the up-regulation of miR-27b in HCMV-infected glioma cells. Our study also provides the first experimental evidence that miR-27b could affect glioma cells’ growth, target EN2 and inhibit its expression in glioma cells. Our data indicate that miR-27b may be related to the development of neurological disorders with HCMV infection. The newly identified miR-27b/EN2 signal pathway may provide new insights into the glioma pathogenesis and a novel target for glioma therapy.

In sickle cell disease (SCD), alterations of cholesterol metabolism is in part related to abnormal levels and activity of plasma proteins such as lecithin cholesterol acyltransferase (LCAT), and apolipoprotein A-I (ApoA-I). In addition, the size distribution of ApoA-I high density lipoproteins (HDL) differs from normal blood. The ratio of the amount of HDL₂ particle relative to the smaller higher density pre-β HDL (HDL₃) particle was shifted toward HDL₂. This lipoprotein imbalance is exacerbated during acute vaso-occlusive episodes (VOE) as the relative levels of HDL₃ decrease. HDL₃ deficiency in SCD plasma was found to relate to a slower ApoA-I exchange rate, which suggests an impaired ABCA1-mediated cholesterol efflux in SCD. HDL₂ isolated from SCD plasma displayed an antioxidant capacity normally associated with HDL₃, providing evidence for a change in function of HDL₂ in SCD as compared to HDL₂ in normal plasma. Although SCD plasma is depleted in HDL₃, this altered capacity of HDL₂ could account for the lack of difference in pro-inflammatory HDL levels in SCD as compared to normal. Exposure of human umbilical vein endothelial cells to HDL₂ isolated from SCD plasma resulted in higher mRNA levels of the acute phase protein long pentraxin 3 (PTX3) as compared to incubation with HDL₂ from control plasma. Addition of the heme-scavenger hemopexin protein prevented increased expression of PTX3 in sickle HDL₂-treated cells. These findings suggest that ApoA-I lipoprotein composition and functions are altered in SCD plasma, and that whole blood transfusion may be considered as a blood replacement therapy in SCD.

Increasing body mass indices (BMIs) across the globe reflect pandemic shifts towards habitual positive energy imbalances. Excess body fat in individuals is often associated with high-energy and high-fat diets scanty in fresh produce. Carotenoids are fat-soluble pigments plentiful in many fruits and vegetables. They are well-known for provitamin A and antioxidant functions, but little research has been done related to carotenoid-body mass interactions. Serum carotenoids were analyzed relative to body fat to determine correlations between major serum carotenoids, retinol, BMI, fat mass, and lean mass. Healthy women (n = 76), 19–50 years old, were categorized into two comparison groups determined by percent body fat measured by air displacement plethysomography (BOD POD®), i.e. <31% and ≥31% fat mass. Anthropometric and three-day diet records were completed for BMI and nutrient intake calculations, respectively. Serum α-carotene concentrations were strongly inversely associated with all measures of body composition (P < 0.001 α-carotene) controlling for dietary intake and age, while β-carotene, lutein, and lycopene were not (P > 0.05). Dietary intake between groups did not differ, including carrot consumption (a high dietary source of α-carotene). These results confirm previous carotenoid-health research and propose the need for further investigation of potential protective roles that α-carotene may perform for optimal health. Serum α-carotene may provide a deeper and clinically relevant purpose, beyond previous suggestions for its use as a biomarker for fruit and vegetable consumption, in that α-carotene may be a biomarker for chronic disease risk frequently linked with obesity.

Neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) is a hereditary metabolic disease arising from biallelic mutations of SLC25A13. This study aimed to explore the characteristics of fasting blood glucose (FBG), fasting insulin (FINS) and C-peptide (C-P) levels in NICCD infants, analyze their SLC25A13 genetic mutations and further discuss the correlation between SLC25A13 genetic mutations and biochemical changes. Seventy-two cases of infants with cholestasis disease were gathered. Among them, 36 cases with NICCD diagnosis were case group. Meanwhile, 36 cases with unknown etiology but excluded NICCD were control group. FBG, FINS, C-P, ALT, AST, GGT, ALP, TG, HDL-C, LDL-C and Non-HDL-C were collected from all subjects, and DNA was extracted from venous blood for SLC25A13 mutations detection. The incidence of hypoglycemia was 3% in NICCD group. There were no significant statistical difference of FBG, FINS and C-P between NICCD and INC groups (P > 0.05). ALT, LDL-C and Non-HDL-C levels in NICCD group were lower than the INC group, while SLC25A13 mutations were associated with the level of GGT (P < 0.05). Ten different SLC25A13 genetic mutations were detected, among which, 851del4, IVS16ins3kb, IVS6+5 G > A and 1638ins23 mutations made up 82% of all mutations. The incidence of hypoglycemia may be higher in small gestational age infants with NICCD. Low LDL-C may be one of the characteristics of dyslipidemia in NICCD infants. There was a correlation between SLC25A13 gene mutations distribution and the GGT level, but the meaning of this finding remains to be further in-depth study.

The purpose of this study was to determine whether obesity would reduce the capacity of peripheral blood mononuclear cells (PBMCs) to produce the anti-inflammatory protein pentraxin 3 (PTX3) in response to ex vivo stimulation with lipopolysaccharide (LPS), and if acute aerobic exercise would enhance this PTX3 production capacity. In addition, the inter-relationships of LPS-induced PTX3 with the inflammatory cytokines (interleukin 6 [IL-6], IL-10, and tumor necrosis factor alpha) were examined. Twenty-one healthy subjects (10 obese and 11 normal-weight) performed an acute bout of aerobic exercise at 75% VO_2max. The capacity of PBMCs to produce PTX3 ex vivo following LPS stimulation was the same in obese and normal-weight subjects at rest, and decreased equally in both subject groups following acute aerobic exercise. This is in contrast to plasma PTX3, which is lower in obese subjects at rest and increased equally in both obese and normal-weight subjects following exercise. In addition, ex vivo PTX3 production was positively associated with IL-6 and IL-10 in response to acute aerobic exercise (r = 0.686, P = 0.020; r = 0.744, P = 0.009, respectively) in normal-weight, but not in obese individuals (r = 0.429, P = 0.249; r = 0.453, P = 0.189, respectively). These findings indicate that concentrations of PTX3 observed in plasma are relatively independent of those produced by PBMCs ex vivo and the mechanisms associated with PTX3-mediated anti-inflammatory signaling may differ during obesity.

Balanced anesthesia allows for a reduced dosage of each component, while inducing general anesthesia of sufficient depth with potentially fewer side effects. Here, we compare two anesthetic protocols combining sevoflurane anesthesia with pre-medication (ketamine [K] or fentanyl-midazolam [FM]) to a sevoflurane monoanesthesia (S) concerning their ability to provide reliable anesthesia suitable for moderate surgery in laboratory mice. Twenty-one female C57BL/6J mice assigned randomly to one of three protocols underwent a 50-min anesthesia and a sham embryo transfer. Heart rate and core body temperature were continuously recorded by telemetry intra-operatively and for three days pre- and three days post-surgery. Intra-operative respiratory rate was determined by counting thorax movements. Body weight, food, and water intake were measured daily for three days pre- and three days post-surgery. The heart rate in the KS group remained at baseline level throughout the 50-min of anesthesia and surgery. FMS caused a lower heart rate and S alone caused a higher heart rate compared to baseline values. Intra-operative body temperature was at baseline levels in all groups. A decreased respiratory rate was observed in all groups compared to baseline values obtained from resting mice of the same strain, sex and age-distribution. Surgical stimuli induced no significant changes in heart rate and respiratory rate in the KS or FMS group but significant respiratory alteration in the S group compared to baseline values obtained 10 s before applying the stimulus. Post-operative heart rate was above baseline values in all groups; with a significant deviation in the S group. There were no changes in body weight, food, and water intake. In summary, FMS was superior to KS and S for moderate surgery in laboratory mice resulting in less inter-individual variability in response to painful stimuli. Fentanyl and midazolam reduced the depressant effect of sevoflurane on the respiratory rate and the negative post-anesthetic effects on the heart rate.

Renal cell carcinoma (RCC) is a malignant tumor, which severely threatens human’s life, moreover, the multi-drug resistance (MDR) under RCC undoubtedly strengthen the difficulties in the treatment. MiR-451 has been considered to play an important role in regulation of MDR in several cancers, but the role of it in MDR of RCC has not been explored. This study aims to explore the mechanism of miR-451 as a target to regulate chemotherapy resistance, which is crucial for further exploring novel therapy for RCC. Two human cell lines (ACHN and GRC-1) were performed in this study and adriamycin (ADM) was used to construct MDR cell lines. qRT-PCR was used to determine the mRNA expression of miR-451 and ATF-2. Weston blot was used to determine protein expression. MTT assay and flow cytometry were used for assessing cell viability and apoptosis, individually. Luciferase reporter assay was used to detect the targeting of miR-451 and ATF-2. Results presented that the expression of miR-451 was higher in low MDR cell line (ACHN) comparing with the high MDR cell line (GRC-1), while the expression of ATF-2 revealed an opposite results. MiR-451 targeted ATF-2 and regulated its expression. Overexpression of miR-451 strengthened drug resistance, decreased cell viability, and increased cell apoptosis of GRC-1 pretreated by ADM, while overexpressed ATF-2 reversed the effect induced by miR-451 overexpression. Then miR-451 knockdown improved drug susceptibility, decreased cell apoptosis, and increased cell viability of ACHN induced by ADM, however, ATF-2 suppression reversed the low rate of cell apoptosis and high rate of cell viability induced by miR-451 knockdown. Our results revealed that miR-451 regulates the drug resistance of RCC by targeting ATF-2 gene, which might be critical for overcoming MDR in RCC patients.