Persons with spinal cord injury (SCI) are in need of effective therapeutics. Estrogen (E2), as a steroid hormone, is a highly pleiotropic agent; with anti-inflammatory, anti-apoptotic, and neurotrophic properties, it is ideal for use in treatment of patients with SCI. Safety concerns around the use of high doses of E2 have limited clinical application, however. To address these concerns, low doses of E2 (25 μg and 2.5 μg) were focally delivered to the injured spinal cord using nanoparticles. A per-acute model (6 h after injury) was used to assess nanoparticle release of E2 into damaged spinal cord tissue; in addition, E2 was evaluated as a rapid anti-inflammatory. To assess inflammation, 27-plex cytokine/chemokine arrays were conducted in plasma, cerebrospinal fluid (CSF), and spinal cord tissue. A particular focus was placed on IL-6, GRO-KC, and MCP-1 as these have been identified from CSF in human studies as potential biomarkers in SCI. S100β, an additional proposed biomarker, was also assessed in spinal cord tissue only. Tissue concentrations of E2 were double those found in the plasma, indicating focal release. E2 showed rapid anti-inflammatory effects, significantly reducing interleukin (IL)-6, GRO-KC, MCP-1, and S100β in one or all compartments. Numerous additional targets of rapid E2 modulation were identified including: leptin, MIP-1α, IL-4, IL-2, IL-10, IFNγ, tumor necrosis factor-α, etc. These data further elucidate the rapid anti-inflammatory effects E2 exerts in an acute rat SCI model, have identified additional targets of estrogen efficacy, and suggest nanoparticle delivered estrogen may provide a safe and efficacious treatment option in persons with acute SCI.
Get full access to this article
View all access options for this article.
References
1.
EiflerA.C., and ThaxtonC.S. (2011). Nanoparticle therapeutics: FDA approval, clinical trials, regulatory pathways, and case study. Methods Mol. Biol., 726, 325–338.
2.
HallE.D. (2003). Drug development in spinal cord injury: what is the FDA looking for?. J. Rehabil. Res. Dev., 40, Suppl 4, 81–91.
3.
SchroederG.D., KwonB.K., EckJ.C., SavageJ.W., HsuW.K., and PatelA.A. (2014). Survey of Cervical Spine Research Society members on the use of high-dose steroids for acute spinal cord injuries. Spine, 39, 971–977.
4.
LammertseD.P. (2013). Clinical trials in spinal cord injury: lessons learned on the path to translation. The 2011 international Spinal Cord Society Sir Ludwig Guttmann Lecture. Spinal Cord, 51, 2–9.
5.
BreslinK., and AgrawalD. (2012). The use of methylprednisolone in acute spinal cord injury: a review of the evidence, controversies, and recommendations. Pediatr. Emerg. Care, 28, 1238–1245.
FehlingsM.G., and BaptisteD.C. (2005). Current status of clinical trials for acute spinal cord injury. Injury, 36, Suppl 2, B113–B122.
8.
TsaiE.C., and TatorC.H. (2005). Neuroprotection and regeneration strategies for spinal cord repair. Curr. Pharm. Des., 11, 1211–1222.
9.
KwonB.K., SekhonL.H., and FehlingsM.G. (2010). Emerging repair, regeneration, and translational research advances for spinal cord injury. Spine, 35, Suppl 21, S263–S270.
10.
CoxA., VarmaA., and BanikN. (2015). Recent advances in the pharmacologic treatment of spinal cord injury. Metab. Brain Dis., 30, 473–482.
11.
LinC.Y., StromA., VegaV.B., KongS.L., YeoA.L., ThomsenJ.S., ChanW.C., DorayB., BangarusamyD.K., RamasamyA., VergaraL.A., TangS., ChongA., BajicV.B., MillerL.D., GustafssonJ.A., and LiuE.T. (2004). Discovery of estrogen receptor alpha target genes and response elements in breast tumor cells. Genome Biol., 5, R66.
12.
SribnickE.A., RayS.K., and BanikN.L. (2004). Estrogen as a multi-active neuroprotective agent in traumatic injuries. Neurochem. Res., 29, 2007–2014.
13.
ryS., SribnickE.A., DasA., ThakoreN.P., MatzelleD., YuS.P., RayS.K., WeiL., and BanikN.L. (2010). Neuroprotective efficacy of estrogen in experimental spinal cord injury in rats. Ann. N. Y. Acad. Sci., 1199, 90–94.
14.
KippM., BergerK., ClarnerT., DangJ., and BeyerC. (2012). Sex steroids control neuroinflammatory processes in the brain: Relevance for acute ischaemia and degenerative demyelination. J. Neuroendocrinol., 24, 62–70.
15.
EvsenM.S., OzlerA., GocmezC., VarolS., TuncS.Y., AkilE., UzarE., and KaplanI. (2013). Effects of estrogen, estrogen/progesteron combination and genistein treatments on oxidant/antioxidant status in the brain of ovariectomized rats. Eur. Rev. Med Pharmacol. Sci., 17, 1869–1873.
16.
KumarS., LataK., MukhopadhyayS., and MukherjeeT.K. (2010). Role of estrogen receptors in pro-oxidative and anti-oxidative actions of estrogens: a perspective. Biochim. Biophys. Acta, 1800, 1127–1135.
17.
CuzzocreaS., GenoveseT., MazzonE., EspositoE., Di PaolaR., MuiaC., CrisafulliC., PeliA., BramantiP., and ChaudryI.H. (2008). Effect of 17beta-estradiol on signal transduction pathways and secondary damage in experimental spinal cord trauma. Shock, 29, 362–371.
18.
ElkabesS., and NicotA.B. (2014). Sex steroids and neuroprotection in spinal cord injury: a review of preclinical investigations. Exp. Neurol., 259, 28–37.
19.
SribnickE.A., SamantarayS., DasA., SmithJ., MatzelleD.D., RayS.K., and BanikN.L. (2010). Postinjury estrogen treatment of chronic spinal cord injury improves locomotor function in rats. J. Neurosci. Res., 88, 1738–1750.
20.
SamantarayS., SmithJ.A., DasA., MatzelleD.D., VarmaA.K., RayS.K., and BanikN.L. (2011). Low dose estrogen prevents neuronal degeneration and microglial reactivity in an acute model of spinal cord injury: effect of dosing, route of administration, and therapy delay. Neurochem. Res., 36, 1809–1816.
21.
RitzM.F., and HausmannO.N. (2008). Effect of 17beta-estradiol on functional outcome, release of cytokines, astrocyte reactivity and inflammatory spreading after spinal cord injury in male rats. Brain Res., 1203, 177–188.
22.
MosqueraL., ColonJ.M., SantiagoJ.M., TorradoA.I., MelendezM., SegarraA.C., Rodriguez-OrengoJ.F., and MirandaJ.D. (2014). Tamoxifen and estradiol improved locomotor function and increased spared tissue in rats after spinal cord injury: their antioxidant effect and role of estrogen receptor alpha. Brain Res., 1561, 11–22.
23.
LeeJ.Y., ChoiS.Y., OhT.H., and YuneT.Y. (2012). 17beta-estradiol inhibits apoptotic cell death of oligodendrocytes by inhibiting RhoA-JNK3 activation after spinal cord injury. Endocrinology, 153, 3815–3827.
24.
YuneT.Y., KimS.J., LeeS.M., LeeY.K., OhY.J., KimY.C., MarkelonisG.J., and OhT.H. (2004). Systemic administration of 17beta-estradiol reduces apoptotic cell death and improves functional recovery following traumatic spinal cord injury in rats. J. Neurotrauma, 21, 293–306.
25.
SiriphornA., DunhamK.A., ChompoopongS., and FloydC.L. (2012). Postinjury administration of 17beta-estradiol induces protection in the gray and white matter with associated functional recovery after cervical spinal cord injury in male rats. J. Comp. Neurol., 520, 2630–2646.
26.
KachadrokaS., HallA.M., NiedzielkoT.L., ChongthammakunS., and FloydC.L. (2010). Effect of endogenous androgens on 17beta-estradiol-mediated protection after spinal cord injury in male rats. J. Neurotrauma, 27, 611–626.
27.
DayN.L., FloydC.L., D'AlessandroT.L., HubbardW.J., and ChaudryI.H. (2013). 17beta-estradiol confers protection after traumatic brain injury in the rat and involves activation of G protein-coupled estrogen receptor 1. J. Neurotrauma, 30, 1531–1541.
28.
ZhangD., HuY., SunQ., ZhaoJ., CongZ., LiuH., ZhouM., LiK., and HangC. (2013). Inhibition of transforming growth factor beta-activated kinase 1 confers neuroprotection after traumatic brain injury in rats. Neuroscience, 238, 209–217.
29.
AslS.Z., KhaksariM., KhachkiA.S., ShahrokhiN., and NourizadeS. (2013). Contribution of estrogen receptors alpha and beta in the brain response to traumatic brain injury. J. Neurosurg., 119, 353–361.
30.
GatsonJ.W., LiuM.M., AbdelfattahK., WiggintonJ.G., SmithS., WolfS., SimpkinsJ.W., and MineiJ.P. (2012). Estrone is neuroprotective in rats after traumatic brain injury. J. Neurotrauma, 29, 2209–2219.
31.
ZlotnikA., LeibowitzA., GurevichB., OhayonS., BoykoM., KleinM., KnyazerB., ShapiraY., and TeichbergV.I. (2012). Effect of estrogens on blood glutamate levels in relation to neurological outcome after TBI in male rats. Intensive Care Med., 38, 137–144.
32.
SoustielJ.F., PalzurE., NevoO., ThalerI., and VlodavskyE. (2005). Neuroprotective anti-apoptosis effect of estrogens in traumatic brain injury. J. Neurotrauma, 22, 345–352.
33.
Perez-AlvarezM.J., Maza MdelC., AntonM., OrdonezL., and WandosellF. (2012). Post-ischemic estradiol treatment reduced glial response and triggers distinct cortical and hippocampal signaling in a rat model of cerebral ischemia. J. Neuroinflammation, 9, 157.
34.
ArdeltA.A., CarpenterR.S., LoboM.R., ZengH., SolankiR.B., ZhangA., KuleszaP., and PikeM.M. (2012). Estradiol modulates post-ischemic cerebral vascular remodeling and improves long-term functional outcome in a rat model of stroke. Brain Res., 1461, 76–86.
35.
ZhangQ.G., RazL., WangR., HanD., De SevillaL., YangF., VadlamudiR.K., and BrannD.W. (2009). Estrogen attenuates ischemic oxidative damage via an estrogen receptor alpha-mediated inhibition of NADPH oxidase activation. J Neurosci., 29, 13823–13836.
36.
LebesgueD., ChevaleyreV., ZukinR.S., and EtgenA.M. (2009). Estradiol rescues neurons from global ischemia-induced cell death: multiple cellular pathways of neuroprotection. Steroids, 74, 555–561.
37.
MerchenthalerI., DellovadeT.L., and ShughrueP.J. (2003). Neuroprotection by estrogen in animal models of global and focal ischemia. Ann. N. Y. Acad. Sci., 1007, 89–100.
38.
LaCroixA.Z., ChlebowskiR.T., MansonJ.E., AragakiA.K., JohnsonK.C., MartinL., MargolisK.L., StefanickM.L., BrzyskiR., CurbJ.D., HowardB.V., LewisC.E., and Wactawski-WendeJ. (2011). Health outcomes after stopping conjugated equine estrogens among postmenopausal women with prior hysterectomy: A randomized controlled trial. JAMA, 305, 1305–1314.
39.
RossouwJ.E., AndersonG.L., PrenticeR.L., LaCroixA.Z., KooperbergC., StefanickM.L., JacksonR.D., BeresfordS.A., HowardB.V., JohnsonK.C., KotchenJ.M., and OckeneJ. (2002). Risks and benefits of estrogen plus progestin in healthy postmenopausal women: Principal results from the Women's Health Initiative randomized controlled trial. JAMA, 288, 321–333.
40.
LidegaardO., EdstromB., and KreinerS. (2002). Oral contraceptives and venous thromboembolism: A five-year national case-control study. Contraception, 65, 187–196.
41.
ZhangL., GuF.X., ChanJ.M., WangA.Z., LangerR.S., and FarokhzadO.C. (2008). Nanoparticles in medicine: therapeutic applications and developments. Clin. Pharmacol. Ther., 83, 761–769.
42.
KwonB.K., StammersA.M., BelangerL.M., BernardoA., ChanD., BishopC.M., SlobogeanG.P., ZhangH., UmedalyH., GiffinM., StreetJ., BoydM.C., PaquetteS.J., FisherC.G., and DvorakM.F. (2010). Cerebrospinal fluid inflammatory cytokines and biomarkers of injury severity in acute human spinal cord injury. J. Neurotrauma, 27, 669–682.
43.
YokoboriS., ZhangZ., MoghiebA., MondelloS., GajavelliS., DietrichW.D., BramlettH., HayesR.L., WangM., WangK.K., and BullockM.R. (2015). Acute diagnostic biomarkers for spinal cord injury: review of the literature and preliminary research report. World Neurosurg., 83, 867–878.
44.
SatishkumarR., and VertegelA.A. (2011). Antibody-directed targeting of lysostaphin adsorbed onto polylactide nanoparticles increases its antimicrobial activity against S. aureus in vitro. Nanotechnology, 22, 505103.
45.
MaximovV.D., ReukovV.V., BarryJ.N., CochraneC., and VertegelA.A. (2010). Protein-nanoparticle conjugates as potential therapeutic agents for the treatment of hyperlipidemia. Nanotechnology, 21, 265103.
46.
PerotP.L.Jr., LeeW.A., HsuC.Y., HoganE.L., CoxR.D., and GrossA.J. (1987). Therapeutic model for experimental spinal cord injury in the rat: I. Mortality and motor deficit. Cent. Nerv. Syst. Trauma, 4, 149–159.
StromJ.O., TheodorssonA., and TheodorssonE. (2008). Substantial discrepancies in 17beta-oestradiol concentrations obtained with three different commercial direct radioimmunoassay kits in rat sera. Scand. J. Clin. Lab. Invest., 68, 806–813.
49.
SaddickS.Y. (2014). Ovarian surface epithelium receptors during pregnancy and estrus cycle of rats with emphasis on steroids and gonadotropin fluctuation. Saudi J. Bio;. Sci., 21, 232–237.
50.
PouwM.H., KwonB.K., VerbeekM.M., VosP.E., van KampenA., FisherC.G., StreetJ., PaquetteS.J., DvorakM.F., BoydM.C., HosmanA.J., and van de MeentH. (2014). Structural biomarkers in the cerebrospinal fluid within 24 h after a traumatic spinal cord injury: A descriptive analysis of 16 subjects. Spinal Cord, 52, 428–433.
51.
BankM., SteinA., SisonC., GlazerA., JassalN., McCarthyD., ShatzerM., HahnB., ChughR., DaviesP., and BloomO. (2015). Elevated circulating levels of the pro-inflammatory cytokine macrophage migration inhibitory factor in individuals with acute spinal cord injury. Arch. Phys. Med. Rehabil., 96, 633–644.
52.
ErtaM., QuintanaA., and HidalgoJ. (2012). Interleukin-6, a major cytokine in the central nervous system. Int. J. Biol. Sci., 8, 1254–1266.
53.
McTigueD.M., TaniM., KrivacicK., ChernoskyA., KelnerG.S., MaciejewskiD., MakiR., RansohoffR.M., and StokesB.T. (1998). Selective chemokine mRNA accumulation in the rat spinal cord after contusion injury. J. Neurosci. Res., 53, 368–376.
54.
StammersA.T., LiuJ., and KwonB.K. (2012). Expression of inflammatory cytokines following acute spinal cord injury in a rodent model. J. Neurosci. Res., 90, 782–790.
55.
NeirinckxV., CosteC., FranzenR., GothotA., RogisterB., and WisletS. (2014). Neutrophil contribution to spinal cord injury and repair. J. Neuroinflammation, 11, 150.
56.
BaoF., FlemingJ.C., GolshaniR., PearseD.D., KasabovL., BrownA., and WeaverL.C. (2011). A selective phosphodiesterase-4 inhibitor reduces leukocyte infiltration, oxidative processes, and tissue damage after spinal cord injury. J. Neurotrauma, 28, 1035–1049.
57.
KossmannT., StahelP.F., LenzlingerP.M., RedlH., DubsR.W., TrentzO., SchlagG., and Morganti-KossmannM.C. (1997). Interleukin-8 released into the cerebrospinal fluid after brain injury is associated with blood-brain barrier dysfunction and nerve growth factor production. J. Cereb. Blood Flow Metab., 17, 280–289.
58.
DeshmaneS.L., KremlevS., AminiS., and SawayaB.E. (2009). Monocyte chemoattractant protein-1 (MCP-1): An overview. J. Interferon Cytokine Res., 29, 313–326.
59.
LeeY.L., ShihK., BaoP., GhirnikarR.S., and EngL.F. (2000). Cytokine chemokine expression in contused rat spinal cord. Neurochem. Int., 36, 417–425.
60.
TaylorA.R., WelshC.J., YoungC., SpoorE., KerwinS.C., GriffinJ.F., LevineG.J., CohenN.D., and LevineJ.M. (2014). Cerebrospinal fluid inflammatory cytokines and chemokines in naturally occurring canine spinal cord injury. J. Neurotrauma, 31, 1561–1569.
61.
SpenceR.D., WisdomA.J., CaoY., HillH.M., MongersonC.R., StapornkulB., ItohN., SofroniewM.V., and VoskuhlR.R. (2013). Estrogen mediates neuroprotection and anti-inflammatory effects during EAE through ERalpha signaling on astrocytes but not through ERbeta signaling on astrocytes or neurons. J. Neurosci., 33, 10924–10933.
62.
DonatoR. (1999). Functional roles of s100 proteins, calcium-binding proteins of the EF-hand type. Biochim. Biophys. Acta, 1450, 191–231.
63.
SribnickE.A., Del ReA.M., RayS.K., WoodwardJ.J., and BanikN.L. (2009). Estrogen attenuates glutamate-induced cell death by inhibiting ca2+influx through L-type voltage-gated ca2+channels. Brain Res., 1276, 159–170.
LoyD.N., SroufeA.E., PeltJ.L., BurkeD.A., CaoQ.L., TalbottJ.F., and WhittemoreS.R. (2005). Serum biomarkers for experimental acute spinal cord injury: rapid elevation of neuron-specific enolase and S-100beta. Neurosurgery, 56, 391–397.
66.
CaoF., YangX.F., LiuW.G., HuW.W., LiG., ZhengX.J., ShenF., ZhaoX.Q., and LvS.T. (2008). Elevation of neuron-specific enolase and S-100beta protein level in experimental acute spinal cord injury. J. Clin. Neurosci., 15, 541–544.
67.
MaJ., NovikovL.N., KarlssonK., KellerthJ.O., and WibergM. (2001). Plexus avulsion and spinal cord injury increase the serum concentration of S-100 protein: an experimental study in rats. Scand. J. Plast. Reconstr. Hand Surg., 35, 355–359.
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
