Small extracellular vesicles derived from human induced pluripotent stem cell-differentiated neural progenitor cells mitigate retinal ganglion cell degeneration in a mouse model of optic nerve injury

Several studies have found that transplantation of neural progenitor cells(NPCs)promotes the survival of injured neurons.However,a poor integration rate and high risk of tumorigenicity after cell transplantation limits their clinical application.Small extracellular vesicles(sEVs)contain bioactive molecules for neuronal protection and regeneration.Previous studies have shown that stem/progenitor cell-derived sEVs can promote neuronal survival and recovery of neurological function in neurodegenerative eye diseases and other eye diseases.In this study,we intravitreally transplanted sEVs derived from human induced pluripotent stem cells(hiPSCs)and hiPSCs-differentiated NPCs(hiPSC-NPC)in a mouse model of optic nerve crush.Our results show that these intravitreally injected sEVs were ingested by retinal cells,especially those localized in the ganglion cell layer.Treatment with hiPSC-NPC-derived sEVs mitigated optic nerve crush-induced retinal ganglion cell degeneration,and regulated the retinal microenvironment by inhibiting excessive activation of microglia.Component analysis further revealed that hiPSC-NPC derived sEVs transported neuroprotective and anti-inflammatory miRNA cargos to target cells,which had protective effects on RGCs after optic nerve injury.These findings suggest that sEVs derived from hiPSC-NPC are a promising cell-free therapeutic strategy for optic neuropathy.

Activation of autophagy in the retina after optic nerve crush injury in rats

AIM: To investigate the activation of autophagy in rat retina after optic nerve crush(ONC) and evaluate its relationship with apoptosis of retinal ganglion cells(RGCs).METHODS: The ONC model was established. Western blots were performed to investigate expression of p62, LC3 and Beclin-1. Transmission electron microscopy was performed to discover the autophagosomes in the retina after ONC. Immunohistochemistry was used to confirm the distribution of LC3. TUNEL was performed to confirm the relationship between autophagy and RGC apoptosis. RESULTS: p62/Beclin-1 ratio was declined shortly after ONC until to day 7 after ONC and then restored to a normal level at day 21. There was an opposite change in the LC3-II/LC3 I ratio in the retina compared to the p62/Beclin-1 ratio. Increased autophagosomes were found after ONC using transmission electron microscopy, and most of the LC3-stained cells were colocalized with RGCs and Müller cells. More LC3-immunoreactive cells and apoptotic RGCs were found on day 7 following ONC. CONCLUSION: Possible activation of autophagy in RGCs after ONC;autophagy mainly occurred in RGCs and Müller cells, and the apoptosis of RGCs after ONC may be partly associated with autophagic activation.

Protective Effect of Paeoniflorin against Optic Nerve Crush

In order to evaluate the efficacy of traditional paeonia extract paeoniflorin against optic nerve crush, 16 Brown Norway rats were divided into two groups at random, with 8 rats in each group. In paeoniaflorin-treated group, 2 mg paeoniaflorin （total volum： 1 mL） was injected into rat＇s peritoneum one time a day for a period of 8 days. Rats in untreated group were given a single dose of vehicle. The optic nerve was crushed by a special forceps for 30 s in the left eye and a sham procedure was performed in the right eye on the 2nd day after the first injection. The retrograde fluorogold labeling of ganglion cells was conducted 5 days after optic nerve crush. The whole retina was flat-mounted thereafter. The ganglion cells that survived the crush were counted under fluorescent microscope by using an automatic counting software. As compared with the contralateral eye, the survival rate of ganglion cells in the left eye increased from 40.22% to 64.53% with a significant difference found between them （t=2.55, P=0.023）. The results suggested that the paeonia extract paeoniflorin possessed a protective effect against optic nerve crush.

Use of a tissue clearing technique combined with retrograde trans-synaptic viral tracing to evaluate changes in mouse retinorecipient brain regions following optic nerve crush

Successful establishment of reconnection between retinal ganglion cells and retinorecipient regions in the brain is critical to optic nerve regeneration.However,morphological assessments of retinorecipient regions are limited by the opacity of brain tissue.In this study,we used an innovative tissue cleaning technique combined with retrograde trans-synaptic viral tracing to observe changes in retinorecipient regions connected to retinal ganglion cells in mice after optic nerve injury.Specifically,we performed light-sheet imaging of whole brain tissue after a clearing process.We found that pseudorabies virus 724(PRV724)mostly infected retinal ganglion cells,and that we could use it to retrogradely trace the retinorecipient regions in whole tissue-cleared brains.Unexpectedly,PRV724-traced neurons were more widely distributed compared with data from previous studies.We found that optic nerve injury could selectively modify projections from retinal ganglion cells in the hypothalamic paraventricular nucleus,intergeniculate leaflet,ventral lateral geniculate nucleus,central amygdala,basolateral amygdala,Edinger-Westphal nucleus,and oculomotor nucleus,but not the superior vestibular nucleus,red nucleus,locus coeruleus,gigantocellular reticular nucleus,or facial nerve nucleus.Our findings demonstrate that the tissue clearing technique,combined with retrograde trans-synaptic viral tracing,can be used to objectively and comprehensively evaluate changes in mouse retinorecipient regions that receive projections from retinal ganglion cells after optic nerve injury.Thus,our approach may be useful for future estimations of optic nerve injury and regeneration.

Valproate reduces retinal ganglion cell apoptosis in rats after optic nerve crush

The retinal ganglion cells of the optic nerve have a limited capacity for self-repair after injury.Valproate is a histone deacetylase inhibitor and multitarget drug,which has been demonstrated to protect retinal neurons.In this study,we established rat models of optic nerve-crush injury and injected valproate into the vitreous cavity immediately after modeling.We evaluated changes in the ultrastructure morphology of the endoplasmic reticulum of retinal ganglion cells over time via transmission electron microscope.Immunohistochemistry and western blot assay revealed that valproate upregulated the expression of the endoplasmic reticulum stress marker glucose-regulated protein 78 and downregulated the expression of transcription factor C/EBP homologous protein,phosphorylated eukaryotic translation initiation factor 2α,and caspase-12 in the endoplasmic reticulum of retinal ganglion cells.These findings suggest that valproate reduces apoptosis of retinal ganglion cells in the rat after optic nerve-crush injury by attenuating phosphorylated eukaryotic translation initiation factor 2α-C/EBP homologous protein signaling and caspase-12 activation during endoplasmic reticulum stress.These findings represent a newly discovered mechanism that regulates how valproate protects neurons.

Promotion of axon regeneration and inhibition of astrocyte activation by alpha A-crystallin on crushed optic nerve

AIM：To explore the effects of αA-crystallin in astrocyte gliosis after optic nerve crush（ONC） and the mechanism of α-crystallin in neuroprotection and axon regeneration.METHODS：ONC was established on the SpragueDawley rat model and αA-crystallin（10 -4 g/L,4 μL） was intravitreously injected into the rat model.Flash-visual evoked potential（F-VEP） was examined 14 d after ONC,and the glial fibrillary acidic protein（GFAP） levels in the retina and crush site were analyzed 1,3,5,7 and 14 d after ONC by immunohistochemistry（IHC） and Western blot respectively.The levels of beta Tubulin（TUJ1）,growth-associated membrane phosphoprotein-43（GAP-43）,chondroitin sulfate proteoglycans（CSPGs） and neurocan were also determined by IHC 14 d after ONC.RESULTS：GFAP level in the retina and the optic nerve significantly increased 1d after ONC,and reached the peak level 7d post-ONC.Injection of αA-crystallin significantly decreased GFAP level in both the retina and the crush site 3d after ONC,and induced astrocytes architecture remodeling at the crush site.Quantification of retinal ganglion cell（RGC） axons indicated αAcrystallin markedly promoted axon regeneration in ONC rats and enhanced the regenerated axons penetrated into the glial scar.CSPGs and neurocan expression also decreased 14 d after αA-crystallin injection.The amplitude（N1-P1） and latency（P1） of F-VEP were also restored.CONCLUSION：Our results suggest α-crystallin promotes the axon regeneration of RGCs and suppresses the activation of astrocytes.

Erythropoietin upregulates growth associated protein-43 expression and promotes retinal ganglion cell axonal regeneration in vivo after optic nerve crush

In this study, we established a rat model of optic nerve crush to explore the effects of erythropoietin on retinal ganglion cell axonal regeneration. At 15 days after injury in erythropoietin treated rats, retinal ganglion cell densities in regions corresponding to the 1/6, 3/6 and 5/6 ratios of the retinal radius were significantly increased. In addition, the number of growth associated protein-43 positive axons was significantly increased at different distances （50, 250 and 500 pm） from the crush site after erythropoietin treatment. Erythropoietin significantly increased growth associated protein-43 protein levels in the retina after crush injury, as determined by westem blot and immunofluorescence analysis. These results demonstrate that erythropoietin protects injured retinal ganglion cells and promotes axonal regeneration.

Protective effects of Achyranthes bidentata polypeptides on retinal ganglion cells post-optic nerve crush in rats

Achyranthes bidentata polypeptides（ABPP） have been reported to inhibit apoptosis of retinal ganglion cells（RGCs）.The present study investigated the protective effects of ABPP on RGCs in a rat model of optic nerve injury.With prolonged injury time,RGC densities were gradually decreased.ABPP（5 μg） significantly increased RGC densities and upregulated growth associated protein 43 expression in rats with optic nerve injury.Results demonstrate that ABPP can protect RGCs and promote axonal growth after optic nerve crush.

Optic nerve injury-induced regeneration in the adult zebrafish is accompanied by spatiotemporal changes in mitochondrial dynamics

Axonal regeneration in the central nervous system is an energy-intensive process.In contrast to mammals,adult zebrafish can functionally recover from neuronal injury.This raises the question of how zebrafish can cope with this high energy demand.We previously showed that in adult zebrafish,subjected to an optic nerve crush,an antagonistic axon-dendrite interplay exists wherein the retraction of retinal ganglion cell dendrites is a prerequisite for effective axonal repair.We postulate a‘dendrites for regeneration’paradigm that might be linked to intraneuronal mitochondrial reshuffling,as ganglion cells likely have insufficient resources to maintain dendrites and restore axons simultaneously.Here,we characterized both mitochondrial distribution and mitochondrial dynamics within the different ganglion cell compartments(dendrites,somas,and axons)during the regenerative process.Optic nerve crush resulted in a reduction of mitochondria in the dendrites during dendritic retraction,whereafter enlarged mitochondria appeared in the optic nerve/tract during axonal regrowth.Upon dendritic regrowth in the retina,mitochondrial density inside the retinal dendrites returned to baseline levels.Moreover,a transient increase in mitochondrial fission and biogenesis was observed in retinal ganglion cell somas after optic nerve damage.Taken together,these findings suggest that during optic nerve injury-induced regeneration,mitochondria shift from the dendrites to the axons and back again and that temporary changes in mitochondrial dynamics support axonal and dendritic regrowth after optic nerve crush.

Phosphorylated S6K1 and 4E-BP1 play different roles in constitutively active Rheb-mediated retinal ganglion cell survival and axon regeneration after optic nerve injury

Ras homolog enriched in brain(Rheb) is a small GTPase that activates mammalian target of rapamycin complex 1(mTORC1).Previous studies have shown that constitutively active Rheb can enhance the regeneration of sensory axons after spinal cord injury by activating downstream effectors of mTOR.S6K1 and4E-BP1 are important downstream effectors of mTORC1.In this study,we investigated the role of Rheb/mTOR and its downstream effectors S6K1 and 4E-BP1in the protection of retinal ganglion cells.We transfected an optic nerve crush mouse model with adeno-associated viral 2-mediated constitutively active Rheb and observed the effects on retinal ganglion cell survival and axon regeneration.We found that overexpression of constitutively active Rheb promoted survival of retinal ganglion cells in the acute(14 days) and chronic(21 and 42 days) stages of injury.We also found that either co-expression of the dominant-negative S6K1mutant or the constitutively active 4E-BP1 mutant together with constitutively active Rheb markedly inhibited axon regeneration of retinal ganglion cells.This suggests that mTORC1-mediated S6K1 activation and 4E-BP1 inhibition were necessary components for constitutively active Rheb-induced axon regeneration.However,only S6K1 activation,but not 4E-BP1 knockdown,induced axon regeneration when applied alone.Furthermore,S6K1 activation promoted the survival of retinal ganglion cells at 14 days post-injury,whereas 4E-BP1 knockdown unexpectedly slightly decreased the survival of retinal ganglion cells at 14 days postinjury.Ove rexpression of constitutively active 4E-BP1 increased the survival of retinal ganglion cells at 14 days post-injury.Likewise,co-expressing constitutively active Rheb and constitutively active 4E-BP1 markedly increased the survival of retinal ganglion cells compared with overexpression of constitutively active Rheb alone at 14 days post-injury.These findings indicate that functional 4E-BP1 and S6K1 are neuroprotective and that 4E-BP1 may exert protective effects through a pathway at least partially independent of Rhe b/mTOR.Together,our results show that constitutively active Rheb promotes the survival of retinal ganglion cells and axon regeneration through modulating S6K1 and 4E-BP1 activity.Phosphorylated S6K1 and 4E-BP1 promote axon regeneration but play an antagonistic role in the survival of retinal ganglion cells.

Mechanisms implicated in the contralateral effect in the central nervous system after unilateral injury:focus on the visual system

The retina,as part of the central nervous system is an ideal model to study the response of neurons to injury and disease and to test new treatments.During the last decade is becoming clear that unilateral lesions in bilateral areas of the central nervous system trigger an inflammatory response in the contralateral uninjured site.This effect has been better studied in the visual system where,as a rule,one retina is used as experimental and the other as control.Contralateral retinas in unilateral models of retinal injury show neuronal degeneration and glial activation.The mechanisms by which this adverse response in the central nervous system occurs are discussed in this review,focusing primarily on the visual system.

Altered Energy Metabolism During Early Optic Nerve Crush Injury:Implications of Warburg-Like Aerobic Glycolysis in Facilitating Retinal Ganglion Cell Survival

Neurons,especially axons,are metabolically demanding and energetically vulnerable during injury.However,the exact energy budget alterations that occur early after axon injury and the effects of these changes on neuronal survival remain unknown.Using a classic mouse model of optic nerve-crush injury,we found that traumatized optic nerves and retinas harbor the potential to mobilize two primary energetic machineries,glycolysis and oxidative phosphorylation,to satisfy the robustly increased adenosine triphosphate(ATP) demand.Further exploration of metabolic activation showed that mitochondrial oxidative phosphorylation was amplified over other pathways,which may lead to decreased retinal ganglion cell(RGC) survival despite its supplement to ATP production.Gene set enrichment analysis of a microarray(GSE32309) identified significant activation of oxidative phosphorylation in injured retinas from wild-type mice compared to those from mice with deletion of phosphatase and tensin homolog(PTEN),while PTEN-/-mice had more robust RGC survival.Therefore,we speculated that the oxidation-favoring metabolic pattern after optic nervecrush injury could be adverse for RGC survival.After redirecting metabolic flux toward glycolysis(magnifying the Warburg effect) using the drug meclizine,we successfully increased RGC survival.Thus,we provide novel insights into a potential bioenergetics-based strategy for neuroprotection.

小鼠视网膜神经节细胞在视神经损伤后的基因表达谱分析

目的:揭示小鼠视神经损伤后视网膜神经节细胞(RGCs)凋亡的分子机制和潜在的治疗靶点。方法:构建视神经损伤(ONC)小鼠模型,对视网膜组织进行HE染色观察组织病理学改变,并使用实时荧光定量PCR(RT-qPCR)检测RGCs标志物—具有多重剪接的RNA结合蛋白(Rbpms)的mRNA表达水平;透射电镜(TEM)观察RGCs线粒体损伤情况;采用转录组测序分析ONC 7 d组小鼠的视网膜差异表达基因,并对差异表达基因进行Gene Ontology(GO)功能、Kyoto Encyclopedia of Genes and Genomes(KEGG)通路富集和韦恩分析,RT-qPCR检测差异基因mRNA表达水平。结果:与正常组相比,ONC 7 d组RGCs数量显著减少,细胞排列疏松不规则,RGCs标志物Rbpms的mRNA表达水平显著降低(P<0.001),ONC小鼠模型构建成功。透射电镜结果表明,ONC 7 d组RGCs的线粒体出现肿胀,嵴消失;转录组测序结果表明,ONC 7 d组与正常组比,存在562个差异表达基因,其中152个基因表达下调和410个基因表达上调。GO功能富集分析和KEGG通路富集分析表明ONC后差异表达基因主要富集于神经元损伤修复的多个重要信号通路;RT-qPCR结果显示,与正常组相比,与神经元损伤修复相关的基因Ecel1、Atf3、Sprr1a的表达均在损伤后第4天显著上调(均P<0.05),与测序结果一致。结论:ONC小鼠RGCs凋亡与线粒体损伤有关,而神经元损伤修复相关基因Atf3、Ecel1、Sprr1a在视神经损伤的早期参与了小鼠视神经损伤后RGCs的保护。

管内段视神经损伤的诊断和疗效分析

目的分析管内段视神经损伤所致视力障碍的诊断要点、疗效及影响愈后的因素。方法对２６例（２７侧）管内段视神经损伤继发视力障碍的患者，经眶部ＣＴ检查后，在药物治疗的同时，采用鼻外开筛进路视神经减压术治疗。结果该病的眶部ＣＴ检查总阳性率为６６７％，其中视神经管骨折阳性率为８１３％，视神经水肿阳性率为５５．６％。伤后立即出现视力障碍者有效率为５７．１％，非伤后立即出现视力障碍者有效率为８３３％。术中明确发现有视神经管骨折者有效率为５６．３％，仅见视神经水肿者有效率为６６．７％。手术时机愈晚，疗效愈差。结论眶部ＣＴ检查对管内段视神经损伤具有重要诊断价值，ＣＴ检查阴性不能除外该病；疗效与视神经损伤程度和手术时机等因素有关。

外伤性视神经损伤后视神经及视网膜形态的动态观察

目的 :了解外伤性视神经损伤后的病理变化、溃变特点与时相间的关系。方法 :参照Allen脊髓损伤法 ,造成视神经眶尖段间接 6 0 0gcm力冲击、挤压伤。伤后对视神经和视网膜行形态学动态观察。结果 :①伤后 4 8h ,视神经轻度肿胀和空泡反应 ;1周时损伤处视神经出现溃变 ,神经胶质细胞增生 ,视网膜神经节细胞 (retinalganglioncells,RGCs)形态改变不明显 ;2周时神经纤维轴束间空泡样改变 ,局灶性坏死 ,RGCs核固缩和细胞数量减少。术后 3月 ,视神经损伤部位直径缩小 ,形成胶质疤痕 ,RGCs数量明显减少 ,核固缩细胞增多。②RGCs数量于术后 4 8h、1周、2周、1月和 3月分别比正常对照组低 3 35 %、13 2 3%、19 74 %、2 3 2 0 %、2 9 2 8%。③视网膜细胞在 4 8h内出现凋亡。结论 :本实验模型可造成明确的视神经和视网膜损伤 ,神经元的损伤程度从节细胞、中间神经元、感光细胞的次序依次递减。视网膜和视神经损伤的严重程度与时间呈相关性。RGCs数量在 4 8h至 1周时下降速率最快。

CNTF和Ad-BDNF对视神经夹伤后视网膜神经节细胞存活的影响

目的：观察大鼠视神经夹伤后玻璃体腔内注射睫状神经营养因子（CNTF）和腺病毒介导脑源性神经营养因子（Ad-BDNF）对视神经损伤后视网膜神经节细胞（RGC）存活的影响。方法：制作大鼠视神经定量夹伤模型，玻璃体腔内注射CNTF和Ad-BDNF，经上丘荧光金（FG）逆行标记RGC，计数视网膜铺片上的RGC并行统计学分析。结果：正常SD大鼠视网膜上RGC密度为2155±265个／mm。（n=12），视神经夹伤后RGC在1～2wk内下降速率最快，到3，4wk时RGC细胞数量虽仍有减少但下降速度已经明显减慢。CNTF组在视神经夹伤后1wk时视网膜RGC数显著高于对照组，但2～4wk的结果和对照组比较差异不明显。Ad—BDNF组视神经夹伤后1～4wk视网膜RGC数均显著高于对照组。结论：CNTF治疗组玻璃体腔内一次性注射CNTF可以在损伤早期2wk内为损伤的RGC提供神经营养因子，减少RGC的早期死亡。Ad．BDNF治疗组的这种保护作用可以持续到损伤后4wk，能够为RGC提供长时间地营养支持，但这种作用比较局限，可能与单一营养因子作用有关。

神经营养因子影响视神经夹伤后视网膜GAP-43mRNA表达变化

目的:观察大鼠视神经夹伤后视网膜上GAP-43基因的变化,观察玻璃体腔内注射睫状神经营养因子(ciliarnyeurotrophicfacto,rCNTF)和腺病毒介导脑源性神经营养因子(adenovirallydeliveredbrain-dreivedneurotrophicfacto,rAd-BDNF)对视网膜上GAP-43mRNA的影响。方法:成年SD大鼠球后2mm处作视神经夹伤模型,经巩膜玻璃体腔内注射微量神经营养因子(neurotraphicfactor,sNFs),应用原位杂交法观察视网膜的GAP-43mRNA的变化。结果:正常SD大鼠视网膜上仅在节细胞层检测到少数细胞存在GAP-43mRNA杂交信号,对照组和CNTF治疗组视神经夹伤后1wk内可观察到视网膜神经节层中存在较强的GAP-43mRNA杂交信号,伤后2wk时已减弱至伤前,Ad-BDNF治疗组在视神经夹伤后4wk内在视网膜上均能观察到GAP-43mRNA的杂交信号,其中在夹伤后1～2wk时杂交信号相对较强。结论:视神经夹伤能上调视网膜上GAP-43mRNA表达,玻璃体腔内注射Ad-BDNF在伤后4wk内均能上调视网膜上GAP-43mRNA表达。

外伤性视神经病变外科治疗的意义及疗效

目的 探讨外伤性视神经病变 (traumaticopticneuropathy ,TON)外科治疗的意义及疗效。方法 分析 5 2例 (5 3眼 )经鼻内镜视神经管减压术 (5 3眼 )和眶尖减压术 (8眼 )的治疗效果 ,随访 6个月～ 3年。结果 2 1眼获视力改善 (39 6 % ) ,其中皮质类固醇激素治疗无效进而采取手术者 14眼有效 (14 /37,37 8% ) ,未经激素治疗即手术者 7眼有效 (7/16 ,4 3 8% ) ;无光感者 18眼获视力改善 (18/4 9 ,36 7% ) ,术前有残余视力者 3眼有效 (3/4 ,75 0 % )。结论 外科治疗对提高TON疗效有重要意义。

表没食子儿茶素没食子酸酯对大鼠视神经钳夹伤后胶质纤维酸性蛋白表达的影响

背景先前的研究已证实，绿茶提取物表没食子儿茶素没食子酸酯（EGCG）能提高大鼠视神经钳夹伤后视网膜神经节细胞（RGCs）的生存率。星形胶质细胞（AS）在神经系统损伤中对神经元的修复起重要作用，而EGCG对视神经钳夹伤后AS反应活性的影响尚有待证实。胶质纤维酸性蛋白（GFAP）是AS的特异性标记物。目的观察EGCG对大鼠视神经钳夹伤后视神经GFAP表达的影响。方法将72只Wistar大鼠随机分为正常对照组、假手术＋EGCG组、视神经钳夹伤＋生理盐水组、视神经钳夹伤＋EGCG组，每组18只。于大鼠球后2mm处用夹持力dOg的微型视神经夹垂直视神经钳夹60s建立视神经钳夹伤模型，似手术大鼠仅切开眼外软组织，不损伤视神经。假手术＋EGCG组和视神经钳夹伤＋EGCG组大鼠术前2d起每日给予25mg／kgEGCG腹腔注射至术后2d，随后改为每日2mg／kg口服。采用免疫组织化学染色及Westernblot法检测并比较各组大鼠造模后7、1d、28d视神经组织中GFAP的表达。结果免疫组织化学染色显示，正常对照组和假手术＋EGCG组视神经组织中GFAP呈弱表达；造模后7、14、28d，视神经钳夹伤＋生理盐水组GFAP表达明显增强，视神经钳夹伤＋EGCG组GFAP的表达强于正常对照组，弱于视神经钳夹伤＋生理盐水组。Westernblot检测表明，造模后视神经组织GFAP的表达量较正常对照组明显增高，差异有统计学意义（P〈0．01）；造模后7d、14d，视神经钳夹伤＋EGCG组GFAP的表达量明显低于视神经钳夹伤＋生理盐水组，差异均有统计学意义（P〈0．05）。结论全身应用EGCG可以下调大鼠视神经钳夹伤后视神经组织中GFAP的表达，降低AS的增生活性，提示EGCG可以抑制视神经创伤修复过程中的瘢痕形成。

视神经损伤后RhoA在大鼠视网膜中的分布及表达研究

目的观察视神经损伤后RhoA在大鼠视网膜中的分布及表达变化。方法将36只成年Long Evans大鼠随机分为正常组,视神经损伤1、3、7d组,共4组,每组9只,通过免疫组化染色,观察RhoA在视网膜中的分布变化;用Western blot分析统计RhoA表达变化。结果正常及视神经损伤后1d,RhoA主要分布于视网膜神经节细胞(retinal gan-glion cells,RGCs)层;3d分布于RGCs及内丛状层;7d分布于RGCs、内丛状层、内核层及外丛状层。Western blot示:视神经损伤后1、3、7d,RhoA表达均高于正常组(P<0.01,P<0.05),但7d表达量最高。结论视神经损伤可显著增加RhoA在视网膜中的表达量及分布范围,它在视神经损伤后再生过程中发挥重要的作用。