The integrity of retinal ganglion cells is tightly associated with diabetic macular degeneration that leads to damage and death of retinal ganglion cells,affecting vision.The major clinical treatments for diabetic mac...The integrity of retinal ganglion cells is tightly associated with diabetic macular degeneration that leads to damage and death of retinal ganglion cells,affecting vision.The major clinical treatments for diabetic macular edema are anti-vascular endothelial growth factor drugs and laser photocoagulation.However,although the macular thickness can be normalized with each of these two therapies used alone,the vision does not improve in many patients.This might result from the incomplete recovery of retinal ganglion cell injury.Therefore,a prospective,non-randomized,controlled clinical trial was designed to investigate the effect of anti-vascular endothelial growth factor drugs combined with laser photocoagulation on the integrity of retinal ganglion cells in patients with diabetic macular edema and its relationship with vision recovery.In this trial,150 patients with diabetic macular edema will be equally divided into three groups according to therapeutic methods,followed by treatment with anti-vascular endothelial growth factor drugs,laser photocoagulation therapy,and their combination.All patients will be followed up for 12 months.The primary outcome measure is retinal ganglion cell-inner plexiform layer thickness at 12 months after treatment.The secondary outcome measures include retinal ganglion cell-inner plexiform layer thickness before and 1,3,6,and 9 months after treatment,retinal nerve fiber layer thickness,best-corrected visual acuity,macular area thickness,and choroidal thickness before and 1,3,6,9,and 12 months after treatment.Safety measure is the incidence of adverse events at 1,3,6,9,and 12 months after treatment.The study protocol hopes to validate the better efficacy and safety of the combined treatment in patients with diabetic macula compared with the other two monotherapies alone during the 12-month follow-up period.The trial is designed to focus on clarifying the time-effect relationship between imaging measures related to the integrity of retinal ganglion cells and best-corrected visual acuity.The trial protocol was approved by the Medical Ethics Committee of the Affiliated Hospital of Beihua University with approval No.(2023)(26)on April 25,2023,and was registered with the Chinese Clinical Trial Registry(registration number:ChiCTR2300072478,June 14,2023,protocol version:2.0).展开更多
Glaucoma,characterized by a degenerative loss of retinal ganglion cells,is the second leading cause of blindness worldwide.There is currently no cure for vision loss in glaucoma because retinal ganglion cells do not r...Glaucoma,characterized by a degenerative loss of retinal ganglion cells,is the second leading cause of blindness worldwide.There is currently no cure for vision loss in glaucoma because retinal ganglion cells do not regenerate and are not replaced after injury.Human stem cell-derived retinal ganglion cell transplant is a potential therapeutic strategy for retinal ganglion cell degenerative diseases.In this review,we first discuss a 2D protocol for retinal ganglion cell differentiation from human stem cell culture,including a rapid protocol that can generate retinal ganglion cells in less than two weeks and focus on their transplantation outcomes.Next,we discuss using 3D retinal organoids for retinal ganglion cell transplantation,comparing cell suspensions and clusters.This review provides insight into current knowledge on human stem cell-derived retinal ganglion cell differentiation and transplantation,with an impact on the field of regenerative medicine and especially retinal ganglion cell degenerative diseases such as glaucoma and other optic neuropathies.展开更多
Intraocular pressure elevation can induce retinal ganglion cell death and is a clinically reversible risk factor for glaucoma,the leading cause of irreversible blindness.We previously demonstrated that casein kinase-2...Intraocular pressure elevation can induce retinal ganglion cell death and is a clinically reversible risk factor for glaucoma,the leading cause of irreversible blindness.We previously demonstrated that casein kinase-2 inhibition can promote retinal ganglion cell survival and axonal regeneration in rats after optic nerve injury.To investigate the underlying mechanism,in the current study we increased the intraocular pressure of adult rats to 75 mmHg for 2 hours and then administered a casein kinase-2 inhibitor(4,5,6,7-tetrabromo-2-azabenzimidazole or 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole)by intravitreal injection.We found that intravitreal injection of 4,5,6,7-tetrabromo-2-azabenzimidazole or 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole promoted retinal ganglion cell survival and reduced the number of infiltrating macrophages.Transcriptomic analysis showed that the mitogen activated protein kinase signaling pathway was involved in the response to intraocular pressure elevation but was not modulated by the casein kinase-2 inhibitors.Furthermore,casein kinase-2 inhibition downregulated the expression of genes(Cck,Htrsa,Nef1,Htrlb,Prph,Chat,Slc18a3,Slc5a7,Scn1b,Crybb2,Tsga10ip,and Vstm21)involved in intraocular pressure elevation.Our data indicate that inhibition of casein kinase-2 can enhance retinal ganglion cell survival in rats after acute intraocular pressure elevation via macrophage inactivation.展开更多
AIM:To investigate the effects of Sonic hedgehog(Shh)gene-modified bone marrow mesenchymal stem cells(MSCs)on graft-induced retinal gliosis and retinal ganglion cells(RGCs)survival in diabetic mice.METHODS:Bone marrow...AIM:To investigate the effects of Sonic hedgehog(Shh)gene-modified bone marrow mesenchymal stem cells(MSCs)on graft-induced retinal gliosis and retinal ganglion cells(RGCs)survival in diabetic mice.METHODS:Bone marrow-derived MSCs were genetically modified with the Shh gene to generate a stably transfected cell line of Shh-modified MSCs(MSC-Shh).Intravitreal injections of MSC-Shh and green fluorescent protein-modified MSCs(MSC-Gfp;control)were administered in diabetic mice.After 4wk,the effects of MSC-Shh on retinal gliosis were evaluated using fundus photography,and markers of gliosis were examined by immunofluorescence and Western blotting.The neurotrophic factors expression and RGCs survival in the host retina were evaluated using Western blotting and immunofluorescence.The mechanisms underlying the effects of MSC-Shh was investigated.RESULTS:A significant reduction of proliferative vitreoretinopathy(PVR)was observed after intravitreal injection of MSC-Shh compared to MSC-Gfp.Significant downregulation of glial fibrillary acidic protein(GFAP)was demonstrated in the host retina after MSC-Shh administration compared to MSC-Gfp.The extracellular signal-regulated kinase 1/2(ERK1/2),protein kinase B(AKT)and phosphatidylin-ositol-3-kinase(PI3K)pathways were significantly downregulated after MSC-Shh administration compared to MSC-Gfp.Brain-derived neurotrophic factor(BDNF)and ciliary neurotrophic factor(CNTF)levels were significantly increased in the host retina,and RGCs loss was significantly prevented after MSC-Shh administration.CONCLUSION:MSC-Shh administration reduces graft-induced reactive gliosis following intravitreal injection in diabetic mice.The ERK1/2,AKT and PI3K pathways are involved in this process.MSC-Shh also increases the levels of neurotrophic factors in the host retina and promoted RGCs survival in diabetic mice.展开更多
Normal tension glaucoma(NTG)is a multifactorial optic neuropathy characterized by normal intraocular pressure,progressive retinal ganglion cell(RGC)death,and glaucomatous visual field loss.Recent studies have describe...Normal tension glaucoma(NTG)is a multifactorial optic neuropathy characterized by normal intraocular pressure,progressive retinal ganglion cell(RGC)death,and glaucomatous visual field loss.Recent studies have described the mechanisms underlying the pathogenesis of NTG.In addition to controlling intraocular pressure,neuroprotection and reduction of RGC degeneration may be beneficial therapies for NTG.In this review,we summarized the main regulatory mechanisms of RGC death in NTG,including autophagy,glutamate neurotoxicity,oxidative stress,neuroinflammation,immunity,and vasoconstriction.Autophagy can be induced by retinal hypoxia and axonal damage.In this process,ischemia can cause mutations of optineurin and activate the nuclear factor-kappa B pathway.Glutamate neurotoxicity is induced by the over-stimulation of N-methyl-D-aspartate membrane receptors by glutamate,which occurs in RGCs and induces progressive glaucomatous optic neuropathy.Oxidative stress also participates in NTG-related glaucomatous optic neuropathy.It impairs the mitochondrial and DNA function of RGCs through the apoptosis signal-regulating kinase-JUN N-terminal kinase pathway.Moreover,it increases inflammation and the immune response of RGCs.Endothelin 1 causes endothelial dysfunction and impairment of ocular blood flow,promoting vasospasm and glaucomatous optic neuropathy,as a result of NTG.In conclusion,we discussed research progress on potential options for the protection of RGCs,including TANK binding kinase 1 inhibitors regulating autophagy,N-methyl-D-aspartate receptor antagonists inhibiting glutamate toxicity,ASK1 inhibitors regulating mitochondrial function,and antioxidants inhibiting oxidative stress.In NTG,RGC death is regulated by a network of mechanisms,while various potential targets protect RGCs.Collectively,these findings provide insight into the pathogenesis of NTG and potential therapeutic strategies.展开更多
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 neuro...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.展开更多
The accumulation of excessive reactive oxygen species can exacerbate any injury of retinal tissue because free radicals can trigger lipid peroxidation,protein damage and DNA fragmentation.Increased oxidative stress is...The accumulation of excessive reactive oxygen species can exacerbate any injury of retinal tissue because free radicals can trigger lipid peroxidation,protein damage and DNA fragmentation.Increased oxidative stress is associated with the common pathological process of many eye diseases,such as glaucoma,diabetic retinopathy and ischemic optic neuropathy.Many studies have demonstrated that Lycium barbarum polysaccharides(LBP)protects against oxidative injury in numerous cells and tissues.For the model of hypoxia we used cultured retinal ganglion cells and induced hypoxia by incubating with 200μM cobalt chloride(CoCl2)for 24 hours.To investigate the protective effect of LBP and its mechanism of action against oxidative stress injury,the retinal tissue was pretreated with 0.5 mg/mL LBP for 24 hours.The results of flow cytometric analysis showed LBP could effectively reduce the CoCl2-induced retinal ganglion cell apoptosis,inhibited the generation of reactive oxygen species and the reduction of mitochondrial membrane potential.These findings suggested that LBP could protect retinal ganglion cells from CoCl2-induced apoptosis by reducing mitochondrial membrane potential and reactive oxygen species.展开更多
Retinal ganglion cell(RGC) degeneration is irreversible in glaucoma and tyrosine kinase receptor B(Trk B)-associated signaling pathways have been implicated in the process.In this study,we attempted to examine whether...Retinal ganglion cell(RGC) degeneration is irreversible in glaucoma and tyrosine kinase receptor B(Trk B)-associated signaling pathways have been implicated in the process.In this study,we attempted to examine whether imipramine,a tricyclic antidepressant,may protect hydrogen peroxide(H_2O_2)-induced RGC degeneration through the activation of the Trk B pathway in RGC-5 cell lines.RGC-5 cell lines were pre-treated with imipramine 30 minutes before exposure to H_2O_2.Western blot assay showed that in H_2O_2-damaged RGC-5 cells,imipramine activated Trk B pathways through extracellular signal-regulated protein kinase/Trk B phosphorylation.TUNEL staining assay also demonstrated that imipramine ameliorated H_2O_2-induced apoptosis in RGC-5 cells.Finally,Trk B-Ig G intervention was able to reverse the protective effect of imipramine on H_2O_2-induced RGC-5 apoptosis.Imipramine therefore protects RGCs from oxidative stress-induced apoptosis through the Trk B signaling pathway.展开更多
AIM: To explore the effect of ciliary neurotrophic factor(CNTF) on retinal ganglion cell(RGC)-5 induced by hydrogen peroxide(H_2O_2). METHODS: After cell adherence, RGC-5 culture medium was changed to contain differen...AIM: To explore the effect of ciliary neurotrophic factor(CNTF) on retinal ganglion cell(RGC)-5 induced by hydrogen peroxide(H_2O_2). METHODS: After cell adherence, RGC-5 culture medium was changed to contain different concentrations of H_2O_2 from50 to 150 μmol/L at four time points(0.5, 1, 1.5 and 2 h) to select the concentration and time point for H_2O_2 induced model. Two different ways of interventions for injured RGC-5 cells respectively were CNTF as an addition in the culture medium or recombinant lentiviral plasmid carrying CNTF gene transfecting bone mesenchymal stem cells(BMSCs) for co-culture with RGC-5. RESULTS: Compared to the control group, H_2O_2 led to RGC-5 death closely associated with concentrations and action time of H_2O_2 and we chose 125 μmol/L and 2 h to establish the H_2O_2-induced model. While CNTF inhibited the loss of RGC-5 cells obviously with a dose-dependent survival rate. Nevertheless two administration routes had different survival rate yet higher rate in recombinant lentiviral plasmid group but there were no statistically significant differences. CONCLUSION: Both the two administration routes of CNTF have effects on RGC-5 cells induced by H_2O_2. If their own advantages were combined, there may be a better administration route.展开更多
AIM: To explore if ischemic preconditioning(IPC) can enhance the survival of retinal ganglion cells(RGCs) after optic nerve axotomy. METHODS: Twenty-four hours prior to retinal ischemia 60 min or axotomy, IPC was appl...AIM: To explore if ischemic preconditioning(IPC) can enhance the survival of retinal ganglion cells(RGCs) after optic nerve axotomy. METHODS: Twenty-four hours prior to retinal ischemia 60 min or axotomy, IPC was applied for ten minutes in groups of(n=72) animals. The survival of RGCs, the cellular expression of heat shock protein 27(HSP27) and heat shock protein 70(HSP70) and the numbers of retinal microglia in the different groups were quantified at 7 and 14 d post-injury. The cellular expression of HSP27 and HSP70 and changes in the numbers of retinal microglia were quantified to detect the possible mechanism of the protection of the IPC. RESULTS: Ten minutes of IPC promoted RGC survival in both the optic nerve injury(IPC-ONT) and the retinal ischemia 60min(IPC-IR60) groups, examined at 7d and 14 d post-injury. Microglial proliferation showed little correlation with the extent of benefit effects of IPC on the rescue of RGCs. The number of HSP27-positive RGCs was significantly higher in the IPC-ONT group than in the sham IPC-ONT group, although the percentage of HSP27-positive RGCs did not significantly differ between groups. For the IPC-IR60 group, neither the number nor the percentage of the HSP27-positive RGCs differed significantly between the IPC and the sham-operated groups. The number of HSP70-positive RGCs was significantly higher for both the IPC-ONT and the IPC-IR60 experimental groups, but the percentages did not differ. CONCLUSION: The induction of IPC enhances the survival of RGCs against both axotomy and retinal ischemia.展开更多
AIM: To confirm the changes in proteins related with hypoxia-induced retinal cell death and to assess the effects of resveratrol(Res).METHODS: The therapeutic effect of Res was verified using an ischemic/reperfusion(I...AIM: To confirm the changes in proteins related with hypoxia-induced retinal cell death and to assess the effects of resveratrol(Res).METHODS: The therapeutic effect of Res was verified using an ischemic/reperfusion(I/R) model in vivo and a hypoxia modelin retinal ganglion cells(RGCs) in vitro.Death of RGCs were confirmed by TUNEL assay.Protein expression was confirmed by Western blotting and immunohistochemistry.In addition, flow cytometric analysis was used to confirm the response in the cell unit to obtain more accurate data.RESULTS: ErbB2 expression and apoptosis in the ganglion cell layer(GCL) increased after I/R injury.Treatment of Res rescued I/R-induced ganglion cell death, downregulated apoptosis and ErbB2 protein expression in the retina.In subsequent in vitro models, Res affects apoptosis by regulating the phosphorylation and expression of mouse double minute 2 homolog(MDM2), along with those of ErbB2.These results suggest that Res reverses GCL-specific apoptosis via downregulation of ErbB2 in ischemic injury.CONCLUSION: In light of Res favorable properties, it should be evaluated in the treatment of RGC death and related retinal disease characterized by ErbB2 and MDM2 expression.Therefore, Res is appropriate therapeutic agent for treating ischemic injury-related eye diseases by targeting the expression of ErbB2 and MDM2.展开更多
Purpose:To characterizes the progression of glaucoma in DBA/2J mice by measuring intraocular pressure(IOP) and retinal ganglion cells(RGCs) numbers in mice of various ages. Methods:A quantitative assessment of the pat...Purpose:To characterizes the progression of glaucoma in DBA/2J mice by measuring intraocular pressure(IOP) and retinal ganglion cells(RGCs) numbers in mice of various ages. Methods:A quantitative assessment of the pathophysiology of the DBA/2J mice was performed and the C57/BL6 mice was used as control. The IOP was measured by the servo-null micropipette system; the regional patterns of the loss of RGCs were determined by cell count of retrogradely-labeled RGCs. Results:The baseline IOP for DBA/2J mice at 7 weeks was (16.6 ± 1.2)mm Hg.Then IOP increased extend to 12 months, with the peak of (25.2 ± 1.2)mm Hg at 6 months of age. Retinal ganglion cell numbers did not decrease relative to control until 12 months of age(P=0.006), when the loss was proportionally higher in peripheral regions(P<0.05). Conclusion:The elevation in IOP precedes the loss of RGCs by several months. RGCs cell loss occurs particularly in peripheral regions of the retina. These findings expand our understanding of the changes in DBA/2J mice and provide information for experiments design when they are used as a glaucoma model for future studies of RGCs degeneration in glaucoma.展开更多
miRNA are short non-coding RNA responsible for the knockdown of proteins through their targeting and silencing of complimentary m RNA sequences.The mi RNA landscape of a cell thus affects the levels of its proteins an...miRNA are short non-coding RNA responsible for the knockdown of proteins through their targeting and silencing of complimentary m RNA sequences.The mi RNA landscape of a cell thus affects the levels of its proteins and has significant consequences to its health.Deviations in this mi RNA landscape have been implicated in a variety of neurodegenerative diseases and have also garnered interest as targets for treatment.Retinal ganglion cells are the sole projection neuron of the retina with their axons making up the optic nerve.They are a focus of study not only for their importance in vision and the myriad of blinding diseases characterized by their dysfunction and loss,but also as a model of other central nervous system diseases such as spinal cord injury and traumatic brain injury.This review summarizes current knowledge on the role of mi RNA in retinal ganglion cell function,highlighting how perturbations can result in disease,and how modulating their abundance may provide a novel avenue of therapeutic research.展开更多
BACKGROUND:Previous studies have shown that nerve regeneration factor (NRF) provides neuroprotective effects. However,the neuroprotective effects on retinal ganglion cells in an animal model of glaucoma remain uncerta...BACKGROUND:Previous studies have shown that nerve regeneration factor (NRF) provides neuroprotective effects. However,the neuroprotective effects on retinal ganglion cells in an animal model of glaucoma remain uncertain. OBJECTIVE:To determine the neuroprotective effects of NRF on retinal ganglion cells in a rabbit model of acute hyper-intraocular pressure and to compare the effects on brain-derived neurotrophic factor (BDNF). DESIGN,TIME AND SETTING:A randomized,controlled,animal experiment was performed at Jiangsu Provincial Key Laboratory of Neural Regeneration from September 2006 to August 2007. MATERIALS:Sterone,a major component of NRF,was provided by the Key Laboratory of Neural Regeneration,Nantong University in China; BDNF was provided by BioDesign Inc.,USA. METHODS:A total of 24 healthy rabbits were randomly assigned to NRF,BDNF,and phosphate buffered saline groups,with 8 rabbits per group. The left eyes were considered normal controls,and acute hyper-intraocular pressure was induced in the right eyes via anterior chamber perfusion. The right camera vitrea bulbi was injected with 4.5 μg NRF,3.75 μg BDNF,or 5 μL 0.1 mol/L phosphate buffered saline,respectively. MAIN OUTCOME MEASURES:Retinal ganglion cells were reverse-labeled using horseradish peroxidase to quantify cell density at 2,4,and 6 mm from the optic disc edge. RESULTS:NRF increased the number of surviving retinal ganglion cells at the optic disc edge (P < 0.01 or P < 0.05). The density of surviving retinal ganglion cells decreased with increasing distance from the optic disc. The number of retinal ganglion cells in the BDNF group was similar to the NRF group (P > 0.05). At 2,4,and 6 mm away from the optic disc edge,there was no significant difference in retinal ganglion cell density between NRF and BDNF groups (P > 0.05). CONCLUSION:NRF provided protection to retinal ganglion cells in a rabbit model of acute hyper-intraocular pressure,i.e.,NRF enhanced the survival rate of retinal ganglion cells. The neuroprotective effect was similar to BDNF.展开更多
The mammalian retina displays incomplete intrinsic regenerative capacities;therefore,retina degeneration is a major cause of irreversible blindness such as glaucoma,agerelated macular degeneration and diabetic retinop...The mammalian retina displays incomplete intrinsic regenerative capacities;therefore,retina degeneration is a major cause of irreversible blindness such as glaucoma,agerelated macular degeneration and diabetic retinopathy.These diseases lead to the loss of retinal cells and serious vision loss in the late stage.Stem cell transplantation is a great promising novel treatment for these incurable retinal degenerative diseases and represents an exciting area of regenerative neurotherapy.Several suitable stem cell sources for transplantation including human embryonic stem cells,induced pluripotent stem cells and adult stem cells have been identified as promising target populations.However,the retina is an elegant neuronal complex composed of various types of cells with different functions.The replacement of these different types of cells by transplantation should be addressed separately.So far,retinal pigment epithelium transplantation has achieved the most advanced stage of clinical trials,while transplantation of retinal neurons such as retinal ganglion cells and photoreceptors has been mostly studied in pre-clinical animal models.In this review,we opine on the key problems that need to be addressed before stem cells transplantation,especially for replacing injured retinal ganglion cells,may be used practically for treatment.A key problem we have called the Switchboard Dilemma is a major block to have functional retinal ganglion cell replacement.We use the public switchboard telephone network as an example to illustrate different difficulties for replacing damaged components in the retina that allow for visual signaling.Retinal ganglion cell transplantation is confronted by significant hurdles,because retinal ganglion cells receive signals from different interneurons,integrate and send signals to the correct targets of the visual system,which functions similar to the switchboard in a telephone network-therefore the Switchboard Dilemma.展开更多
AIM:To observe the protective effect of human umbilical cord mesenchymal stem cells(huc MSCs)on retinal ganglion cel s(RGCs)injury in mice with acute ocular hypertension(AOH).METHODS:Fifty-six adult male C57 BL/6 mice...AIM:To observe the protective effect of human umbilical cord mesenchymal stem cells(huc MSCs)on retinal ganglion cel s(RGCs)injury in mice with acute ocular hypertension(AOH).METHODS:Fifty-six adult male C57 BL/6 mice were randomly divided into four groups:normal group,AOH group,huc MSCs group,normal saline(NS)group.Left eye of mice was induced by 90 mm Hg intraocular pressure for 1 h to establish AOH model.huc MSCs 1×105/μL,1μL or NS 1μL was injected into the vitreous body the next day.CMDil fluorescent dye was used to label the 3 rd generation of huc MSCs,for tracing the cells in the vitreous cavity of mice.Seven days after the model established,hematoxylin-eosin(HE)staining was used to observe the thickness of the inner retina layer in four groups.Numbers and loss rate of RGCs were evaluated by counting Brn-3 a positive cells stained by immunofluorescencein.RESULTS:On the 7 th day after AOH established,labeled huc MSCs were found in the vitreous cavity.HE staining showed that the thickness of retinal inner layer in AOH group was significantly lower than that in normal group and huc MSCs group(P<0.05),same as that in NS group(P>0.05).Compared with AOH group,the RGCs in normal group was significantly higher;RGCs number increased in huc MSCs group and the loss rate was lower(P<0.05).Injection of NS had no protective effect on RGCs.CONCLUSION:In AOH mouse model,vitreous injection of hucMSCs have shown a protection for RGCs.展开更多
AIM: To investigate the effect of interleukin-8(IL-8) on neural retinal ganglion cells(RGCs) and whether it can be alleviated by G31P. METHODS: RGC-5 cells were exposed to IL-8 with or without its specific receptor an...AIM: To investigate the effect of interleukin-8(IL-8) on neural retinal ganglion cells(RGCs) and whether it can be alleviated by G31P. METHODS: RGC-5 cells were exposed to IL-8 with or without its specific receptor antagonist G31P for 24h, and the cell viability was assessed by Cell Counting Kit 8(CCK-8). Apoptosis was measured by examining nuclear morphology and quantifying with flow cytometry. Reverse transcription quantitative real-time polymerase chain reaction(RT-qP CR) and Western blot were used to investigate the expression of apoptosis-related genes. RESULTS: CCK-8 assay showed that IL-8 significantly inhibits the viability of RGC-5 cells in a dose-dependent manner. Cell apoptosis assays exhibited higher apoptotic rate in IL-8 treatment group compared to control group. We further found that IL-8 could promote Bax and caspase-3 expressions, but decrease the level of Bcl-2 in the aspect of m RNA and protein. However, pre-treatment with G31P partly attenuated these effects in RGC-5 cells(P<0.05).CONCLUSION: These results indicate that anti-proliferation effects of IL-8 through induction of cell apoptosis regulated by Bcl-2, Bax and caspase-3 expressions, can be ameliorated by G31P.展开更多
Inflammation is a critical pathophysiological process that modulates neuronal survival in the central nervous system after disease or injury.However,the effects and mechanisms of macrophage activation on neuronal surv...Inflammation is a critical pathophysiological process that modulates neuronal survival in the central nervous system after disease or injury.However,the effects and mechanisms of macrophage activation on neuronal survival remain unclear.In the present study,we co-cultured adult Fischer rat retinas with primary peritoneal macrophages or zymosan-treated peritoneal macrophages for 7 days.Immunofluorescence analysis revealed that peritoneal macrophages reduced retinal ganglion cell survival and neurite outgrowth in the retinal explant compared with the control group.The addition of zymosan to peritoneal macrophages attenuated the survival and neurite outgrowth of retinal ganglion cells.Conditioned media from peritoneal macrophages also reduced retinal ganglion cell survival and neurite outgrowth.This result suggests that secretions from peritoneal macrophages mediate the inhibitory effects of these macrophages.In addition,increased inflammationand oxidation-related gene expression may be related to the enhanced retinal ganglion cell degeneration caused by zymosan activation.In summary,this study revealed that primary rat peritoneal macrophages attenuated retinal ganglion cell survival and neurite outgrowth,and that macrophage activation further aggravated retinal ganglion cell degeneration.This study was approved by the Animal Ethics Committee of the Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong,Shantou,Guangdong Province,China,on March 11,2014(approval no.EC20140311(2)-P01).展开更多
Retinal ganglion cell(RGC) axons provide the only link between the light sensitive and photon transducing neural retina and visual centers of the brain.RGC axon degeneration occurs in a number of blinding diseases and...Retinal ganglion cell(RGC) axons provide the only link between the light sensitive and photon transducing neural retina and visual centers of the brain.RGC axon degeneration occurs in a number of blinding diseases and the ability to stimulate axon regeneration from surviving ganglion cells could provide the anatomic substrate for restoration of vision.OTX2 is a homeoprotein transcription factor expressed in the retina and previous studies showed that,in response to stress,exogenous OTX2 increases the in vitro and in vivo survival of RGCs.Here we examined and quantified the effects of OTX2 on adult RGC axon regeneration in vitro and in vivo.The results show that exogenous OTX2 stimulates the regrowth of axons from RGCs in cultures of dissociated adult retinal cells and from explants of adult retinal tissue and that RGCs respond directly to OTX2 as regrowth is observed in cultures of purified adult rat RGCs.Importantly,after nerve crush in vivo,we observed a positive effect of OTX2 on the number of regenerating axons up to the optic chiasm within 14 days post crush and a very modest level of acuity absent in control mice.The effect of OTX2 on RGC survival and regeneration is of potential interest for degenerative diseases affecting this cell type.All animal procedures were approved by the local "Comié d'éιthique en expérimentation animale n°59" and authorization n° 00702.01 delivered March 28,2014 by the French "Ministére de l'enseignement supérieur et de la recherche".展开更多
BACKGROUND:Retinal microglia has been shown to reactivate in a murine model of pigmentary glaucoma.However,the relationship between microglial activation and intraocular pressure(IOP) elevation and retinal ganglion ce...BACKGROUND:Retinal microglia has been shown to reactivate in a murine model of pigmentary glaucoma.However,the relationship between microglial activation and intraocular pressure(IOP) elevation and retinal ganglion cell(RGC) death is still unclear.OBJECTIVE:To verify that microglial activation and tumor necrosis factor alpha(TNF-α) expression is involved in RGC death with elevated IOP and prolonged time of glaucomatous optic nerve lesion in a DBA/2J mouse model of glaucoma.DESIGN,TIME AND SETTING:This randomized,controlled,animal experiment was performed at the Peking University Third Hospital,Peking University Eye Center,China between December 2006 and May 2008.MATERIALS:DBA/2J mice and C57BL/6J mice(Jackson Laboratory,USA),rat anti-mouse CD11b monoclonal antibody(Serotec,UK),and goat anti-TNF-α polyclonal antibody(Sigma,USA) were used in this study.METHODS:A total of 100 female,DBA/2J mice at 3,6,9,12,and 14 months of age(20 mice per age group) were used for the glaucoma model,and 18 C57BL/6J mice at 3,9,14 months of age(6 mice per age group) were used as normal controls.The anterior segment of the eye was ob-served using a slit-lamp biomicroscope.IOP was measured using a microneedle system.Morphology and number of retinal microglia were observed using immunohistochemistry.RGCs were quantified using Nissl staining.Co-localization of TNF-α and microglia was observed using double-labeling immunofluorescence.Excavation of the optic nerve head was observed utilizing he-matoxylin-eosin staining.MAIN OUTCOME MEASURES:The following parameters were measured:IOP levels,numbers of RGCs and activated microglia,and TNF-α expression.RESULTS:In 6-month-old DBA/2J mice,dispersed pigment was observed,and some mice devel-oped increased IOP.At 9 months of age,IOP levels reached a peak.In 3-month-old DBA/2J mice,microglia were activated.In 6-month-old DBA/2J mice,the number of activated microglia was significantly increased and migrated to the outer retinal layer.In 9-month-old mice,TNF-α expression was co-localized with microglia.Significant RGC loss occurred in mice aged 9 to 14 months,with the presence of optic nerve fiber loss and optical nerve head excavation.IOP returned to normal levels at 12 months of age,but microglia remained activated,which was consistent with RGC loss.CONCLUSION:Retinal microglial activation was partially attributed to increased IOP.Activated microglia might be mainly responsible for RGC loss.TNF-α expression was evident in the inner retinal layer.However,the relationship between TNF-α and RGC loss remains poorly understood.展开更多
基金supported by Science and Technology Research Project of Jilin Provincial Department of Education,No.JJKH20220072KJ(to XL)Science and Technology Development Program of Jilin Province,No.20200201495JC(to YL)。
文摘The integrity of retinal ganglion cells is tightly associated with diabetic macular degeneration that leads to damage and death of retinal ganglion cells,affecting vision.The major clinical treatments for diabetic macular edema are anti-vascular endothelial growth factor drugs and laser photocoagulation.However,although the macular thickness can be normalized with each of these two therapies used alone,the vision does not improve in many patients.This might result from the incomplete recovery of retinal ganglion cell injury.Therefore,a prospective,non-randomized,controlled clinical trial was designed to investigate the effect of anti-vascular endothelial growth factor drugs combined with laser photocoagulation on the integrity of retinal ganglion cells in patients with diabetic macular edema and its relationship with vision recovery.In this trial,150 patients with diabetic macular edema will be equally divided into three groups according to therapeutic methods,followed by treatment with anti-vascular endothelial growth factor drugs,laser photocoagulation therapy,and their combination.All patients will be followed up for 12 months.The primary outcome measure is retinal ganglion cell-inner plexiform layer thickness at 12 months after treatment.The secondary outcome measures include retinal ganglion cell-inner plexiform layer thickness before and 1,3,6,and 9 months after treatment,retinal nerve fiber layer thickness,best-corrected visual acuity,macular area thickness,and choroidal thickness before and 1,3,6,9,and 12 months after treatment.Safety measure is the incidence of adverse events at 1,3,6,9,and 12 months after treatment.The study protocol hopes to validate the better efficacy and safety of the combined treatment in patients with diabetic macula compared with the other two monotherapies alone during the 12-month follow-up period.The trial is designed to focus on clarifying the time-effect relationship between imaging measures related to the integrity of retinal ganglion cells and best-corrected visual acuity.The trial protocol was approved by the Medical Ethics Committee of the Affiliated Hospital of Beihua University with approval No.(2023)(26)on April 25,2023,and was registered with the Chinese Clinical Trial Registry(registration number:ChiCTR2300072478,June 14,2023,protocol version:2.0).
基金supported by NIH Core Grants P30-EY008098the Eye and Ear Foundation of Pittsburghunrestricted grants from Research to Prevent Blindness,New York,NY,USA(to KCC)。
文摘Glaucoma,characterized by a degenerative loss of retinal ganglion cells,is the second leading cause of blindness worldwide.There is currently no cure for vision loss in glaucoma because retinal ganglion cells do not regenerate and are not replaced after injury.Human stem cell-derived retinal ganglion cell transplant is a potential therapeutic strategy for retinal ganglion cell degenerative diseases.In this review,we first discuss a 2D protocol for retinal ganglion cell differentiation from human stem cell culture,including a rapid protocol that can generate retinal ganglion cells in less than two weeks and focus on their transplantation outcomes.Next,we discuss using 3D retinal organoids for retinal ganglion cell transplantation,comparing cell suspensions and clusters.This review provides insight into current knowledge on human stem cell-derived retinal ganglion cell differentiation and transplantation,with an impact on the field of regenerative medicine and especially retinal ganglion cell degenerative diseases such as glaucoma and other optic neuropathies.
基金supported by the National Natural Science Foundation of China,Nos.81570849,81100931the Natural Science Foundation of Guangdong Province of China,Nos.2015A030313446,2020A1515011413(all to LPC).
文摘Intraocular pressure elevation can induce retinal ganglion cell death and is a clinically reversible risk factor for glaucoma,the leading cause of irreversible blindness.We previously demonstrated that casein kinase-2 inhibition can promote retinal ganglion cell survival and axonal regeneration in rats after optic nerve injury.To investigate the underlying mechanism,in the current study we increased the intraocular pressure of adult rats to 75 mmHg for 2 hours and then administered a casein kinase-2 inhibitor(4,5,6,7-tetrabromo-2-azabenzimidazole or 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole)by intravitreal injection.We found that intravitreal injection of 4,5,6,7-tetrabromo-2-azabenzimidazole or 2-dimethylamino-4,5,6,7-tetrabromo-1H-benzimidazole promoted retinal ganglion cell survival and reduced the number of infiltrating macrophages.Transcriptomic analysis showed that the mitogen activated protein kinase signaling pathway was involved in the response to intraocular pressure elevation but was not modulated by the casein kinase-2 inhibitors.Furthermore,casein kinase-2 inhibition downregulated the expression of genes(Cck,Htrsa,Nef1,Htrlb,Prph,Chat,Slc18a3,Slc5a7,Scn1b,Crybb2,Tsga10ip,and Vstm21)involved in intraocular pressure elevation.Our data indicate that inhibition of casein kinase-2 can enhance retinal ganglion cell survival in rats after acute intraocular pressure elevation via macrophage inactivation.
基金Supported by the Natural Science Foundation of Guangdong Province(No.2018A0303130293,No.2023A1515012470).
文摘AIM:To investigate the effects of Sonic hedgehog(Shh)gene-modified bone marrow mesenchymal stem cells(MSCs)on graft-induced retinal gliosis and retinal ganglion cells(RGCs)survival in diabetic mice.METHODS:Bone marrow-derived MSCs were genetically modified with the Shh gene to generate a stably transfected cell line of Shh-modified MSCs(MSC-Shh).Intravitreal injections of MSC-Shh and green fluorescent protein-modified MSCs(MSC-Gfp;control)were administered in diabetic mice.After 4wk,the effects of MSC-Shh on retinal gliosis were evaluated using fundus photography,and markers of gliosis were examined by immunofluorescence and Western blotting.The neurotrophic factors expression and RGCs survival in the host retina were evaluated using Western blotting and immunofluorescence.The mechanisms underlying the effects of MSC-Shh was investigated.RESULTS:A significant reduction of proliferative vitreoretinopathy(PVR)was observed after intravitreal injection of MSC-Shh compared to MSC-Gfp.Significant downregulation of glial fibrillary acidic protein(GFAP)was demonstrated in the host retina after MSC-Shh administration compared to MSC-Gfp.The extracellular signal-regulated kinase 1/2(ERK1/2),protein kinase B(AKT)and phosphatidylin-ositol-3-kinase(PI3K)pathways were significantly downregulated after MSC-Shh administration compared to MSC-Gfp.Brain-derived neurotrophic factor(BDNF)and ciliary neurotrophic factor(CNTF)levels were significantly increased in the host retina,and RGCs loss was significantly prevented after MSC-Shh administration.CONCLUSION:MSC-Shh administration reduces graft-induced reactive gliosis following intravitreal injection in diabetic mice.The ERK1/2,AKT and PI3K pathways are involved in this process.MSC-Shh also increases the levels of neurotrophic factors in the host retina and promoted RGCs survival in diabetic mice.
基金supported in part by the Technology Foundation of Tianjin Eye Hospital of China, No. YKQN1911 (to WCS)Tianjin Health Science and Technology Project, No. TJWJ2021QN071 (to WCS)Translational Medicine Research Project of State Key Laboratory of Experimental Hematology of China, No. Z21-11 (to BQH)
文摘Normal tension glaucoma(NTG)is a multifactorial optic neuropathy characterized by normal intraocular pressure,progressive retinal ganglion cell(RGC)death,and glaucomatous visual field loss.Recent studies have described the mechanisms underlying the pathogenesis of NTG.In addition to controlling intraocular pressure,neuroprotection and reduction of RGC degeneration may be beneficial therapies for NTG.In this review,we summarized the main regulatory mechanisms of RGC death in NTG,including autophagy,glutamate neurotoxicity,oxidative stress,neuroinflammation,immunity,and vasoconstriction.Autophagy can be induced by retinal hypoxia and axonal damage.In this process,ischemia can cause mutations of optineurin and activate the nuclear factor-kappa B pathway.Glutamate neurotoxicity is induced by the over-stimulation of N-methyl-D-aspartate membrane receptors by glutamate,which occurs in RGCs and induces progressive glaucomatous optic neuropathy.Oxidative stress also participates in NTG-related glaucomatous optic neuropathy.It impairs the mitochondrial and DNA function of RGCs through the apoptosis signal-regulating kinase-JUN N-terminal kinase pathway.Moreover,it increases inflammation and the immune response of RGCs.Endothelin 1 causes endothelial dysfunction and impairment of ocular blood flow,promoting vasospasm and glaucomatous optic neuropathy,as a result of NTG.In conclusion,we discussed research progress on potential options for the protection of RGCs,including TANK binding kinase 1 inhibitors regulating autophagy,N-methyl-D-aspartate receptor antagonists inhibiting glutamate toxicity,ASK1 inhibitors regulating mitochondrial function,and antioxidants inhibiting oxidative stress.In NTG,RGC death is regulated by a network of mechanisms,while various potential targets protect RGCs.Collectively,these findings provide insight into the pathogenesis of NTG and potential therapeutic strategies.
基金supported by the National Natural Science Foundation of China,Nos.30772368(to DH),81371034(to XH)the Key Project of Natural Science Foundation of Shaanxi Province,No.2017JZ025(to DH).
文摘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.
基金supported by grants from Project of Administration of Traditional Chinese Medicine of Guangdong Province of China,No.20161071(to LL)Medical Scientific Research Foundation of Guangdong Province of China,No.A2019098(to LL)
文摘The accumulation of excessive reactive oxygen species can exacerbate any injury of retinal tissue because free radicals can trigger lipid peroxidation,protein damage and DNA fragmentation.Increased oxidative stress is associated with the common pathological process of many eye diseases,such as glaucoma,diabetic retinopathy and ischemic optic neuropathy.Many studies have demonstrated that Lycium barbarum polysaccharides(LBP)protects against oxidative injury in numerous cells and tissues.For the model of hypoxia we used cultured retinal ganglion cells and induced hypoxia by incubating with 200μM cobalt chloride(CoCl2)for 24 hours.To investigate the protective effect of LBP and its mechanism of action against oxidative stress injury,the retinal tissue was pretreated with 0.5 mg/mL LBP for 24 hours.The results of flow cytometric analysis showed LBP could effectively reduce the CoCl2-induced retinal ganglion cell apoptosis,inhibited the generation of reactive oxygen species and the reduction of mitochondrial membrane potential.These findings suggested that LBP could protect retinal ganglion cells from CoCl2-induced apoptosis by reducing mitochondrial membrane potential and reactive oxygen species.
文摘Retinal ganglion cell(RGC) degeneration is irreversible in glaucoma and tyrosine kinase receptor B(Trk B)-associated signaling pathways have been implicated in the process.In this study,we attempted to examine whether imipramine,a tricyclic antidepressant,may protect hydrogen peroxide(H_2O_2)-induced RGC degeneration through the activation of the Trk B pathway in RGC-5 cell lines.RGC-5 cell lines were pre-treated with imipramine 30 minutes before exposure to H_2O_2.Western blot assay showed that in H_2O_2-damaged RGC-5 cells,imipramine activated Trk B pathways through extracellular signal-regulated protein kinase/Trk B phosphorylation.TUNEL staining assay also demonstrated that imipramine ameliorated H_2O_2-induced apoptosis in RGC-5 cells.Finally,Trk B-Ig G intervention was able to reverse the protective effect of imipramine on H_2O_2-induced RGC-5 apoptosis.Imipramine therefore protects RGCs from oxidative stress-induced apoptosis through the Trk B signaling pathway.
基金Supported by Ph.D.Programs Foundation of Ministry of Education of China(No.20130141120052)
文摘AIM: To explore the effect of ciliary neurotrophic factor(CNTF) on retinal ganglion cell(RGC)-5 induced by hydrogen peroxide(H_2O_2). METHODS: After cell adherence, RGC-5 culture medium was changed to contain different concentrations of H_2O_2 from50 to 150 μmol/L at four time points(0.5, 1, 1.5 and 2 h) to select the concentration and time point for H_2O_2 induced model. Two different ways of interventions for injured RGC-5 cells respectively were CNTF as an addition in the culture medium or recombinant lentiviral plasmid carrying CNTF gene transfecting bone mesenchymal stem cells(BMSCs) for co-culture with RGC-5. RESULTS: Compared to the control group, H_2O_2 led to RGC-5 death closely associated with concentrations and action time of H_2O_2 and we chose 125 μmol/L and 2 h to establish the H_2O_2-induced model. While CNTF inhibited the loss of RGC-5 cells obviously with a dose-dependent survival rate. Nevertheless two administration routes had different survival rate yet higher rate in recombinant lentiviral plasmid group but there were no statistically significant differences. CONCLUSION: Both the two administration routes of CNTF have effects on RGC-5 cells induced by H_2O_2. If their own advantages were combined, there may be a better administration route.
文摘AIM: To explore if ischemic preconditioning(IPC) can enhance the survival of retinal ganglion cells(RGCs) after optic nerve axotomy. METHODS: Twenty-four hours prior to retinal ischemia 60 min or axotomy, IPC was applied for ten minutes in groups of(n=72) animals. The survival of RGCs, the cellular expression of heat shock protein 27(HSP27) and heat shock protein 70(HSP70) and the numbers of retinal microglia in the different groups were quantified at 7 and 14 d post-injury. The cellular expression of HSP27 and HSP70 and changes in the numbers of retinal microglia were quantified to detect the possible mechanism of the protection of the IPC. RESULTS: Ten minutes of IPC promoted RGC survival in both the optic nerve injury(IPC-ONT) and the retinal ischemia 60min(IPC-IR60) groups, examined at 7d and 14 d post-injury. Microglial proliferation showed little correlation with the extent of benefit effects of IPC on the rescue of RGCs. The number of HSP27-positive RGCs was significantly higher in the IPC-ONT group than in the sham IPC-ONT group, although the percentage of HSP27-positive RGCs did not significantly differ between groups. For the IPC-IR60 group, neither the number nor the percentage of the HSP27-positive RGCs differed significantly between the IPC and the sham-operated groups. The number of HSP70-positive RGCs was significantly higher for both the IPC-ONT and the IPC-IR60 experimental groups, but the percentages did not differ. CONCLUSION: The induction of IPC enhances the survival of RGCs against both axotomy and retinal ischemia.
基金Supported by the Biomedical Research Institute Fund (GNUHBRIF-2017-0003) from Gyeongsang National University Hospital。
文摘AIM: To confirm the changes in proteins related with hypoxia-induced retinal cell death and to assess the effects of resveratrol(Res).METHODS: The therapeutic effect of Res was verified using an ischemic/reperfusion(I/R) model in vivo and a hypoxia modelin retinal ganglion cells(RGCs) in vitro.Death of RGCs were confirmed by TUNEL assay.Protein expression was confirmed by Western blotting and immunohistochemistry.In addition, flow cytometric analysis was used to confirm the response in the cell unit to obtain more accurate data.RESULTS: ErbB2 expression and apoptosis in the ganglion cell layer(GCL) increased after I/R injury.Treatment of Res rescued I/R-induced ganglion cell death, downregulated apoptosis and ErbB2 protein expression in the retina.In subsequent in vitro models, Res affects apoptosis by regulating the phosphorylation and expression of mouse double minute 2 homolog(MDM2), along with those of ErbB2.These results suggest that Res reverses GCL-specific apoptosis via downregulation of ErbB2 in ischemic injury.CONCLUSION: In light of Res favorable properties, it should be evaluated in the treatment of RGC death and related retinal disease characterized by ErbB2 and MDM2 expression.Therefore, Res is appropriate therapeutic agent for treating ischemic injury-related eye diseases by targeting the expression of ErbB2 and MDM2.
基金This work was supported by Guangdong Scientific researchfund (NO. 2006J1-C0051)
文摘Purpose:To characterizes the progression of glaucoma in DBA/2J mice by measuring intraocular pressure(IOP) and retinal ganglion cells(RGCs) numbers in mice of various ages. Methods:A quantitative assessment of the pathophysiology of the DBA/2J mice was performed and the C57/BL6 mice was used as control. The IOP was measured by the servo-null micropipette system; the regional patterns of the loss of RGCs were determined by cell count of retrogradely-labeled RGCs. Results:The baseline IOP for DBA/2J mice at 7 weeks was (16.6 ± 1.2)mm Hg.Then IOP increased extend to 12 months, with the peak of (25.2 ± 1.2)mm Hg at 6 months of age. Retinal ganglion cell numbers did not decrease relative to control until 12 months of age(P=0.006), when the loss was proportionally higher in peripheral regions(P<0.05). Conclusion:The elevation in IOP precedes the loss of RGCs by several months. RGCs cell loss occurs particularly in peripheral regions of the retina. These findings expand our understanding of the changes in DBA/2J mice and provide information for experiments design when they are used as a glaucoma model for future studies of RGCs degeneration in glaucoma.
基金supported by the Intramural Research Programs of the National Eye Institute (to ST)。
文摘miRNA are short non-coding RNA responsible for the knockdown of proteins through their targeting and silencing of complimentary m RNA sequences.The mi RNA landscape of a cell thus affects the levels of its proteins and has significant consequences to its health.Deviations in this mi RNA landscape have been implicated in a variety of neurodegenerative diseases and have also garnered interest as targets for treatment.Retinal ganglion cells are the sole projection neuron of the retina with their axons making up the optic nerve.They are a focus of study not only for their importance in vision and the myriad of blinding diseases characterized by their dysfunction and loss,but also as a model of other central nervous system diseases such as spinal cord injury and traumatic brain injury.This review summarizes current knowledge on the role of mi RNA in retinal ganglion cell function,highlighting how perturbations can result in disease,and how modulating their abundance may provide a novel avenue of therapeutic research.
文摘BACKGROUND:Previous studies have shown that nerve regeneration factor (NRF) provides neuroprotective effects. However,the neuroprotective effects on retinal ganglion cells in an animal model of glaucoma remain uncertain. OBJECTIVE:To determine the neuroprotective effects of NRF on retinal ganglion cells in a rabbit model of acute hyper-intraocular pressure and to compare the effects on brain-derived neurotrophic factor (BDNF). DESIGN,TIME AND SETTING:A randomized,controlled,animal experiment was performed at Jiangsu Provincial Key Laboratory of Neural Regeneration from September 2006 to August 2007. MATERIALS:Sterone,a major component of NRF,was provided by the Key Laboratory of Neural Regeneration,Nantong University in China; BDNF was provided by BioDesign Inc.,USA. METHODS:A total of 24 healthy rabbits were randomly assigned to NRF,BDNF,and phosphate buffered saline groups,with 8 rabbits per group. The left eyes were considered normal controls,and acute hyper-intraocular pressure was induced in the right eyes via anterior chamber perfusion. The right camera vitrea bulbi was injected with 4.5 μg NRF,3.75 μg BDNF,or 5 μL 0.1 mol/L phosphate buffered saline,respectively. MAIN OUTCOME MEASURES:Retinal ganglion cells were reverse-labeled using horseradish peroxidase to quantify cell density at 2,4,and 6 mm from the optic disc edge. RESULTS:NRF increased the number of surviving retinal ganglion cells at the optic disc edge (P < 0.01 or P < 0.05). The density of surviving retinal ganglion cells decreased with increasing distance from the optic disc. The number of retinal ganglion cells in the BDNF group was similar to the NRF group (P > 0.05). At 2,4,and 6 mm away from the optic disc edge,there was no significant difference in retinal ganglion cell density between NRF and BDNF groups (P > 0.05). CONCLUSION:NRF provided protection to retinal ganglion cells in a rabbit model of acute hyper-intraocular pressure,i.e.,NRF enhanced the survival rate of retinal ganglion cells. The neuroprotective effect was similar to BDNF.
基金supported by the NIH Center Core Grant,No.P30EY014801(to Bascom Palmer Eye Institute)and a Research to Prevent Blindness Unrestricted Grant(to Bascom Palmer Eye Institute)the Walter G.Ross Foundation(to RKL).
文摘The mammalian retina displays incomplete intrinsic regenerative capacities;therefore,retina degeneration is a major cause of irreversible blindness such as glaucoma,agerelated macular degeneration and diabetic retinopathy.These diseases lead to the loss of retinal cells and serious vision loss in the late stage.Stem cell transplantation is a great promising novel treatment for these incurable retinal degenerative diseases and represents an exciting area of regenerative neurotherapy.Several suitable stem cell sources for transplantation including human embryonic stem cells,induced pluripotent stem cells and adult stem cells have been identified as promising target populations.However,the retina is an elegant neuronal complex composed of various types of cells with different functions.The replacement of these different types of cells by transplantation should be addressed separately.So far,retinal pigment epithelium transplantation has achieved the most advanced stage of clinical trials,while transplantation of retinal neurons such as retinal ganglion cells and photoreceptors has been mostly studied in pre-clinical animal models.In this review,we opine on the key problems that need to be addressed before stem cells transplantation,especially for replacing injured retinal ganglion cells,may be used practically for treatment.A key problem we have called the Switchboard Dilemma is a major block to have functional retinal ganglion cell replacement.We use the public switchboard telephone network as an example to illustrate different difficulties for replacing damaged components in the retina that allow for visual signaling.Retinal ganglion cell transplantation is confronted by significant hurdles,because retinal ganglion cells receive signals from different interneurons,integrate and send signals to the correct targets of the visual system,which functions similar to the switchboard in a telephone network-therefore the Switchboard Dilemma.
基金Supported by the National Natural Science Foundation of China(No.81970806)Medical Scientific Research Foundation of Guangdong Province of China(No.A2019098)。
文摘AIM:To observe the protective effect of human umbilical cord mesenchymal stem cells(huc MSCs)on retinal ganglion cel s(RGCs)injury in mice with acute ocular hypertension(AOH).METHODS:Fifty-six adult male C57 BL/6 mice were randomly divided into four groups:normal group,AOH group,huc MSCs group,normal saline(NS)group.Left eye of mice was induced by 90 mm Hg intraocular pressure for 1 h to establish AOH model.huc MSCs 1×105/μL,1μL or NS 1μL was injected into the vitreous body the next day.CMDil fluorescent dye was used to label the 3 rd generation of huc MSCs,for tracing the cells in the vitreous cavity of mice.Seven days after the model established,hematoxylin-eosin(HE)staining was used to observe the thickness of the inner retina layer in four groups.Numbers and loss rate of RGCs were evaluated by counting Brn-3 a positive cells stained by immunofluorescencein.RESULTS:On the 7 th day after AOH established,labeled huc MSCs were found in the vitreous cavity.HE staining showed that the thickness of retinal inner layer in AOH group was significantly lower than that in normal group and huc MSCs group(P<0.05),same as that in NS group(P>0.05).Compared with AOH group,the RGCs in normal group was significantly higher;RGCs number increased in huc MSCs group and the loss rate was lower(P<0.05).Injection of NS had no protective effect on RGCs.CONCLUSION:In AOH mouse model,vitreous injection of hucMSCs have shown a protection for RGCs.
文摘AIM: To investigate the effect of interleukin-8(IL-8) on neural retinal ganglion cells(RGCs) and whether it can be alleviated by G31P. METHODS: RGC-5 cells were exposed to IL-8 with or without its specific receptor antagonist G31P for 24h, and the cell viability was assessed by Cell Counting Kit 8(CCK-8). Apoptosis was measured by examining nuclear morphology and quantifying with flow cytometry. Reverse transcription quantitative real-time polymerase chain reaction(RT-qP CR) and Western blot were used to investigate the expression of apoptosis-related genes. RESULTS: CCK-8 assay showed that IL-8 significantly inhibits the viability of RGC-5 cells in a dose-dependent manner. Cell apoptosis assays exhibited higher apoptotic rate in IL-8 treatment group compared to control group. We further found that IL-8 could promote Bax and caspase-3 expressions, but decrease the level of Bcl-2 in the aspect of m RNA and protein. However, pre-treatment with G31P partly attenuated these effects in RGC-5 cells(P<0.05).CONCLUSION: These results indicate that anti-proliferation effects of IL-8 through induction of cell apoptosis regulated by Bcl-2, Bax and caspase-3 expressions, can be ameliorated by G31P.
基金supported by the National Natural Science Foundation of China,No.81570849(to LPC)the Natural Science Foundation of Guangdong Province of China,No.2020A1515010415(to LPC)+1 种基金the Special Fund for Chinese Medicine Development of Guangdong Province of China,No.20202089(to TKN)the Grant for Key Disciplinary Project of Clinical Medicine under the Guangdong High-Level University Development Program,No.002-18119101.
文摘Inflammation is a critical pathophysiological process that modulates neuronal survival in the central nervous system after disease or injury.However,the effects and mechanisms of macrophage activation on neuronal survival remain unclear.In the present study,we co-cultured adult Fischer rat retinas with primary peritoneal macrophages or zymosan-treated peritoneal macrophages for 7 days.Immunofluorescence analysis revealed that peritoneal macrophages reduced retinal ganglion cell survival and neurite outgrowth in the retinal explant compared with the control group.The addition of zymosan to peritoneal macrophages attenuated the survival and neurite outgrowth of retinal ganglion cells.Conditioned media from peritoneal macrophages also reduced retinal ganglion cell survival and neurite outgrowth.This result suggests that secretions from peritoneal macrophages mediate the inhibitory effects of these macrophages.In addition,increased inflammationand oxidation-related gene expression may be related to the enhanced retinal ganglion cell degeneration caused by zymosan activation.In summary,this study revealed that primary rat peritoneal macrophages attenuated retinal ganglion cell survival and neurite outgrowth,and that macrophage activation further aggravated retinal ganglion cell degeneration.This study was approved by the Animal Ethics Committee of the Joint Shantou International Eye Center of Shantou University and the Chinese University of Hong Kong,Shantou,Guangdong Province,China,on March 11,2014(approval no.EC20140311(2)-P01).
基金supported by Fovea-Pharmaceuticals,and Global Research Laboratory Program Grant 2009-00424 from the Korean Ministry of Education,Science,and Technology,HOMEOSIGN:ERC-2013-AdG n°339379 and Neuropr Otx:ANR-16-CE16-0003-02。
文摘Retinal ganglion cell(RGC) axons provide the only link between the light sensitive and photon transducing neural retina and visual centers of the brain.RGC axon degeneration occurs in a number of blinding diseases and the ability to stimulate axon regeneration from surviving ganglion cells could provide the anatomic substrate for restoration of vision.OTX2 is a homeoprotein transcription factor expressed in the retina and previous studies showed that,in response to stress,exogenous OTX2 increases the in vitro and in vivo survival of RGCs.Here we examined and quantified the effects of OTX2 on adult RGC axon regeneration in vitro and in vivo.The results show that exogenous OTX2 stimulates the regrowth of axons from RGCs in cultures of dissociated adult retinal cells and from explants of adult retinal tissue and that RGCs respond directly to OTX2 as regrowth is observed in cultures of purified adult rat RGCs.Importantly,after nerve crush in vivo,we observed a positive effect of OTX2 on the number of regenerating axons up to the optic chiasm within 14 days post crush and a very modest level of acuity absent in control mice.The effect of OTX2 on RGC survival and regeneration is of potential interest for degenerative diseases affecting this cell type.All animal procedures were approved by the local "Comié d'éιthique en expérimentation animale n°59" and authorization n° 00702.01 delivered March 28,2014 by the French "Ministére de l'enseignement supérieur et de la recherche".
基金the National Natural Science Foundation of China,No.30571986the Research Fund from Peking University Third Hospital
文摘BACKGROUND:Retinal microglia has been shown to reactivate in a murine model of pigmentary glaucoma.However,the relationship between microglial activation and intraocular pressure(IOP) elevation and retinal ganglion cell(RGC) death is still unclear.OBJECTIVE:To verify that microglial activation and tumor necrosis factor alpha(TNF-α) expression is involved in RGC death with elevated IOP and prolonged time of glaucomatous optic nerve lesion in a DBA/2J mouse model of glaucoma.DESIGN,TIME AND SETTING:This randomized,controlled,animal experiment was performed at the Peking University Third Hospital,Peking University Eye Center,China between December 2006 and May 2008.MATERIALS:DBA/2J mice and C57BL/6J mice(Jackson Laboratory,USA),rat anti-mouse CD11b monoclonal antibody(Serotec,UK),and goat anti-TNF-α polyclonal antibody(Sigma,USA) were used in this study.METHODS:A total of 100 female,DBA/2J mice at 3,6,9,12,and 14 months of age(20 mice per age group) were used for the glaucoma model,and 18 C57BL/6J mice at 3,9,14 months of age(6 mice per age group) were used as normal controls.The anterior segment of the eye was ob-served using a slit-lamp biomicroscope.IOP was measured using a microneedle system.Morphology and number of retinal microglia were observed using immunohistochemistry.RGCs were quantified using Nissl staining.Co-localization of TNF-α and microglia was observed using double-labeling immunofluorescence.Excavation of the optic nerve head was observed utilizing he-matoxylin-eosin staining.MAIN OUTCOME MEASURES:The following parameters were measured:IOP levels,numbers of RGCs and activated microglia,and TNF-α expression.RESULTS:In 6-month-old DBA/2J mice,dispersed pigment was observed,and some mice devel-oped increased IOP.At 9 months of age,IOP levels reached a peak.In 3-month-old DBA/2J mice,microglia were activated.In 6-month-old DBA/2J mice,the number of activated microglia was significantly increased and migrated to the outer retinal layer.In 9-month-old mice,TNF-α expression was co-localized with microglia.Significant RGC loss occurred in mice aged 9 to 14 months,with the presence of optic nerve fiber loss and optical nerve head excavation.IOP returned to normal levels at 12 months of age,but microglia remained activated,which was consistent with RGC loss.CONCLUSION:Retinal microglial activation was partially attributed to increased IOP.Activated microglia might be mainly responsible for RGC loss.TNF-α expression was evident in the inner retinal layer.However,the relationship between TNF-α and RGC loss remains poorly understood.
