The onset of retinal degenerative disease is often associated with neuronal loss. Therefore, how to regenerate new neurons to restore vision is an important issue. NeuroD1 is a neural transcription factor with the abi...The onset of retinal degenerative disease is often associated with neuronal loss. Therefore, how to regenerate new neurons to restore vision is an important issue. NeuroD1 is a neural transcription factor with the ability to reprogram brain astrocytes into neurons in vivo. Here, we demonstrate that in adult mice, NeuroD1 can reprogram Müller cells, the principal glial cell type in the retina, to become retinal neurons. Most strikingly, ectopic expression of NeuroD1 using two different viral vectors converted Müller cells into different cell types. Specifically, AAV7 m8 GFAP681::GFP-ND1 converted Müller cells into inner retinal neurons, including amacrine cells and ganglion cells. In contrast, AAV9 GFAP104::ND1-GFP converted Müller cells into outer retinal neurons such as photoreceptors and horizontal cells, with higher conversion efficiency. Furthermore, we demonstrate that Müller cell conversion induced by AAV9 GFAP104::ND1-GFP displayed clear dose-and time-dependence. These results indicate that Müller cells in adult mice are highly plastic and can be reprogrammed into various subtypes of retinal neurons.展开更多
AIM: To investigate if pigment epithelium-derived factor(PEDF) has any protective effect on the retinal Müller cells of Sprague-Dawley rats suffering from diabetes mellitus.METHODS: Sixty Sprague-Dawley rats were...AIM: To investigate if pigment epithelium-derived factor(PEDF) has any protective effect on the retinal Müller cells of Sprague-Dawley rats suffering from diabetes mellitus.METHODS: Sixty Sprague-Dawley rats were randomly divided into a negative control group, a group receiving0.1 μg/μL PEDF, another group receiving 0.2 μg/μL PEDF,and a group receiving balanced salt solution(BSS). Rats in both the PEDF and BSS groups were treated intravitreally based on previously established diabetic models. After 4wk of treatment, morphological alterations of Müller cells and protein expression of glutamine synthase(GS) and glial fibrillary acidic protein(GFAP)were analyzed.RESULTS:PEDFateither0.1μg/μLor0.2μg/μLsignificantly improved the structures of both nuclei and organelles of Müller cells compared to the BSS-treated group.Expression of GS was significantly higher in the 0.2 μg/μL PEDF group than that in the BSS group(P =0.012), but expression of GFAP was significantly lower in the 0.2 μg/μL PEDF group than that in the BSS group(P =0.000);however, there were no significant differences in expression of these proteins between the 0.1 μg/μL PEDF group and the BSS group(P =0.608, P =0.152). CONCLUSION: PEDF protects the morphological ultrastructure of Müller cells, improves the expression of glutamate synthase and prevents cell gliosis.展开更多
Pathophysiological explanations for metamorphopsia associated with retinal pathologies generally focus on photoreceptor organization disruption. However, the retinal microarchitecture is complicated, and we hypothesiz...Pathophysiological explanations for metamorphopsia associated with retinal pathologies generally focus on photoreceptor organization disruption. However, the retinal microarchitecture is complicated, and we hypothesize that other retinal cells may also be involved. Metamorphopsia has been widely studied in eyes with epiretinal membranes and we revisit the idea that Müller cell displacement causes retinal macropsia. A Pub Med query and related article search for the macula ultrastructure under normal and pathological conditions revealed an enormous amount of information, particularly ultrahigh definition optical coherence tomography and other retinal imaging modality studies. Findings of these imaging studies support our hypothesis that Müller cells, and not cone photoreceptors, are primarily responsible for macropsia in eyes with epiretinal membranes. More specifically, we conclude that displacement of Müller cell endfeet, and not photoreceptor cones, is a more likely the explanation for retinal macropsia associated with epiretinal membranes.展开更多
Müller cells(MC) are considered dormant retinal progenitor cells in mammals.Previous studies demonstrated ephrin-As act as negative regulators of neural progenitor cells in the retina and brain.It remains unclear...Müller cells(MC) are considered dormant retinal progenitor cells in mammals.Previous studies demonstrated ephrin-As act as negative regulators of neural progenitor cells in the retina and brain.It remains unclear whether the lack of ephrin-A2/A3 is sufficient to promote the neurogenic potential of MC.Here we investigated whether the MC is the primary retinal cell type expressing ephrin-A2/A3 and their role on the neurogenic potential of Müller cells.In this study, we showed that ephrin-A2/A3 and their receptor EphA4 were expressed in retina and especially enriched in MC.The level of ephrin As/EphA4 expression increased as the retina matured that is correlated with the reduced proliferative and progenitor cell potential of MC.Next, we investigated the proliferation in primary MC cultures isolated from wild-type and A2~(–/–) A3~(–/–) mice by 5-ethynyl-2′-deoxyuridine(EdU) incorporation.We detected a significant increase of EdU~+ cells in MC derived from A2~(–/–) A3~(–/–) mice.Next, we investigated the role of ephrin-A2/A3 in mice undergoing photoreceptor degeneration such as Rhodopsin knockout(Rho~(–/–)) mice.To further evaluate the role of ephrin-A2/A3 in MC proliferation in vivo, EdU was injected intraperitoneally to adult wild-type, A2~(–/–) A3~(–/–), Rho~(–/–) and Rho~(–/–) A2~(–/–) A3~(–/–) mice and the numbers of EdU~+ cells distributed among different layers of the retina.Ephrin As/EphA4 expression was upregulated in the retina of Rho~(–/–) mice compared to the wild-type mice.In addition, cultured MC derived from ephrin-A2~(–/–) A3~(–/–) mice also expressed higher levels of progenitor cell markers and exhibited higher proliferation potential than those from wild-type mice.Interestingly, we detected a significant increase of EdU~+ cells in the retinas of adult ephrin-A2~(–/–) A3~(–/–) mice mainly in the inner nuclear layer;and these EdU~+ cells were co-localized with MC marker, cellular retinaldehyde-binding protein, suggesting some proliferating cells are from MC.In Rhodopsin knockout mice(Rho~(–/–) A2~(–/–) A3~(–/–) mice), a significantly greater amount of EdU~+ cells were located in the ciliary body, retina and RPE than that of Rho~(–/–) mice.Comparing between 6 and 12 weeks old Rho~(–/–) A2~(–/–) A3~(–/–) mice, we recorded more EdU~+ cells in the outer nuclear layer in the 12-week-old mice undergoing severe retinal degeneration.Taken together, Ephrin-A2/A3 are negative regulators of the proliferative and neurogenic potentials of MC.Absence of ephrin-A2/A3 promotes the migration of proliferating cells into the outer nuclear layer and may lead to retinal cell regeneration.All experimental procedures were approved by the Animal Care and Use Committee at Schepens Eye Research Institute, USA(approval No.S-353-0715) on October 24, 2012.展开更多
AIM: To investigate the effect of protein kinase C (PKC) on transforming growth factor-β2 (TGFβ2) and dopamine in retinal Müller cells of guinea pig myopic eye. METHODS: Myopia was induced by translucent goggle...AIM: To investigate the effect of protein kinase C (PKC) on transforming growth factor-β2 (TGFβ2) and dopamine in retinal Müller cells of guinea pig myopic eye. METHODS: Myopia was induced by translucent goggles in guinea pig, whose retinal Müller cells were cultured using the enzyme-digesting method. Retinal Müller cells were divided into 5 groups: normal control, myopia, myopia plus GF109203X, myopia plus PMA, myopia plus DMSO. PKC activities were detected by the non-radioactive methods. TGFβ2 and tyrosine hydroxylase (TH) proteins were analyzed by Western Blotting in retinal Müller cells. Dopamine was determined by the high-performance liquid chromatography- electrochemical detection in suspensions. RESULTS: After 14 days deprived, the occluded eyes became myopic with ocular axle elongating. Müller cells of guinea pigs were obtained using enzyme digestion. Compared with normal control group, the increase in PKC activity and the up-regulation in TGFβ2 expression were found in retinal Müller cells of myopic eyes, with the decrease of TH and dopamine content (P <0.05). After PKC activated by PMA, TGFβ2 and TH content were up-regulated with the increase of dopamine content (P <0.05). While the PKC activities was inhibited by GF109203X, proteins of TGFβ2 and TH were down-regulated in the myopic eyes, with the decrease of dopamine content (P <0.05). CONCLUSION: TGFβ2 and dopamine are modulated by PKC in Müller cells of the myopic eyes in guinea pig.展开更多
AIM:To explore the effects and potential mechanisms of curcumin on retinal Müller cell in early diabetic rats.·METHODS:Diabetic rats were induced by a single intraperitoneal injection of streptozotocin(STZ)....AIM:To explore the effects and potential mechanisms of curcumin on retinal Müller cell in early diabetic rats.·METHODS:Diabetic rats were induced by a single intraperitoneal injection of streptozotocin(STZ).Male Sprague-Dawley(SD) rats were randomly assigned into 4groups:control group(nave SD rats administered with a single intraperitoneal injection of citric buffer),diabetic group(STZ-diabetic rats),dimethyl sulfoxide(DMSO)group(diabetic rats intraperitoneally administered with mixture of DMSO and normal saline,once a day) and curcumin group(diabetic rats intraperitoneally administered with curcumin,80mg/kg,once a day).Three months after diabetes onset,malondialdehyde(MDA,indication of oxidative stress level) and reduced glutathione(GSH) in retina were detected with kits,glial fibrillary acidic protein(GFAP) in retina was revealed by immunohistochemistry and Western blot,and retinal glutamine synthetase(GS) were observed by Western blot.·RESULTS:Compared with control group,retinal MDA was increased,and GSH was decreased in diabetic and DMSO groups(P <0.05,respectively).While,retinal MDA and GSH in curcumin group showed no difference compared with control group(P >0.05).Furthermore,upregulation of retinal GFAP and down-regulation of retinal GS were detected in diabetic and DMSO groups,and no alteration could be observed in curcumin group revealed with Western blot.Compared with control group,retinal Müller cells showed significant increase in GFAP immunochemistry staining in diabetic and DMSO groups.Moreover,GFAP-positive staining was decreased in curcumin group compared with diabetic group.·CONCLUSION:Curcumin inhibits diabetic retinal oxidative stress,protects Müller cell,and prevents thedown-regulation of GS in diabetic retina.Therefore,curcumin has a therapeutic potential in the treatment of diabetic retinopathy(DR).展开更多
AIM: To determine the effect of pirfenidone on the activated human Müller cells by platelet-derived growth factor-BB(PDGF-BB). METHODS: The primary human Müller cells were separated from retinal tissues and ...AIM: To determine the effect of pirfenidone on the activated human Müller cells by platelet-derived growth factor-BB(PDGF-BB). METHODS: The primary human Müller cells were separated from retinal tissues and established the pathogenic model by stimulated with PDGF-BB. The Müller cells behaviour of normal group and the model group was measured by MTT assay, Trypan blue assay, cell migration assay, and collagen contraction assay. The expression of transforming growth factor(TGF)-β1,-β2, and pigment epithelium-derived factor(PEDF) was estimated with realtime polymerase chain reaction(PCR), Western blot and immunofluorescence analyses. RESULTS: A pathogenic/proliferative model of Müller cells was established by stimulating normal cultured Müller cells with 10 ng/mL PDGF-BB for 48 h. After treated with 0.2 and 0.3 mg/mL pirfenidone, the proliferation, migration and collagen contraction was statistically significantly depressed in the model group compared with the normal groups. The expression levels of TGF-β1 and TGF-β2 were significantly down-regulated, while the PEDF expression was significantly up-regulated after treated with 0.2 and 0.3 mg/mL pirfenidone in the model group. CONCLUSION: Pirfenidone effectively suppress the proliferation, migration and collagen contraction of the human Müller cells stimulated with PDGF-BB through down-regulation of TGF-β1/TGF-β2 and up-regulation of PEDF.展开更多
Rho kinase(ROCK) was the first downstream Rho effector found to mediate Rho A-induced actin cytoskeletal changes through effects on myosin light chain phosphorylation. There is abundant evidence that the ROCK pathway ...Rho kinase(ROCK) was the first downstream Rho effector found to mediate Rho A-induced actin cytoskeletal changes through effects on myosin light chain phosphorylation. There is abundant evidence that the ROCK pathway participates in the pathogenesis of retinal endothelial injury and proliferative epiretinal membrane traction. In this study, we investigated the effect of the ROCK pathway inhibitor Y-27632 on retinal Müller cells subjected to hypoxia or oxidative stress. Müller cells were subjected to hypoxia or oxidative stress by exposure to CoCl_2 or H_2 O_2. After a 24-hour treatment with Y-27632, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was used to assess the survival of Müller cells. Hoechst 33258 was used to detect apoptosis, while 2′,7′-dichlorodihydrofluorescein diacetate was used to measure reactive oxygen species generation. A transwell chamber system was used to examine the migration ability of Müller cells. Western blot assay was used to detect the expression levels of α-smooth muscle actin, glutamine synthetase and vimentin. After treatment with Y-27632, Müller cells subjected to hypoxia or oxidative stress exhibited a morphology similar to control cells. Y-27632 reduced apoptosis, α-smooth muscle actin expression and reactive oxygen species generation under oxidative stress, and it reduced cell migration under hypoxia. Y-27632 also upregulated glutamine synthetase expression under hypoxia but did not impact vimentin expression. These findings suggest that Y-27632 protects Müller cells against cellular injury caused by oxidative stress and hypoxia by inhibiting the ROCK pathway.展开更多
Objective:To detect the expression of glial fibrillary acid protein (GFAP) and taurine trans- porter (TauT) in the retinal Müller cells in high glucose culture with taurine and to explore the influence of glucose...Objective:To detect the expression of glial fibrillary acid protein (GFAP) and taurine trans- porter (TauT) in the retinal Müller cells in high glucose culture with taurine and to explore the influence of glucose on the taurine transporting,and the possible protective effects of taurine on Müller cells in early diabetic retinopathy.Methods.The Müller cells from the rat retina were cultured in high glucose,and GFAP and TauT expressions were detected in the cells treated with different doses of taurine by immuocy- tochemical fluorescein staining and Western blotting.Results:High glucose enhanced the expression of GFAP and decreased the expression of TauT in Müller cells.Taurine decreased the up-regulation of GFAP in the cells which was induced by high glucoses 0.1-10mmol/L taurine increased the expression of TauT in Müller cells.Conclusion:Taurine can inhibit the changes in Müller cell resulted from high glucose.展开更多
The aim of this study was to investigate the effects of Avastin on aquaporin4(AQP4) expression in human retinal Müller cells in vitro under hypoxia,so as to explore the mechanism of Avastin treating retinal edema...The aim of this study was to investigate the effects of Avastin on aquaporin4(AQP4) expression in human retinal Müller cells in vitro under hypoxia,so as to explore the mechanism of Avastin treating retinal edema.The human Müller cells were cultured using the enzymatic digestion method.Müller cells were identified under the transmission electron microscopy and by using immunofluorescence staining.By using semi-quantitative reverse transcription polymerase chain reaction(RT-PCR),the expression of AQP4 mRNA and VEGF mRNA in Müller cells cultured with 500 μmol/L CoCl 2 for 0,3,6,12 and 24 h,and with 0,100,300,500 and 700 μmol/L CoCl 2 for 24 h was detected.The expression of AQP4 mRNA in Müller cells cultured with 50 ng/mL exogenous vascular endothelial growth factor(VEGF) for 0,0.5,1,2 and 4 h,and with 0,25,50 and 75 ng/mL VEGF for 24 h was detected.Amplified cDNA products of AQP4 mRNA in Müller cells cultured with 500 μmol/L CoCl 2 and 200 μg/mL Avastin for 24 h were detected.The results showed that more than 95% cells displayed positive immunofluorescence reaction.Characteristic 8-10 nm intracellular filaments could be seen in the cytoplasm under the transmission electron microscopy.In the CoCl 2 experimental groups,the expression of AQP4 mRNA and VEGF mRNA in Müller cells was increased as compared with the control group.Alteration of AQP4 mRNA and VEGF mRNA levels showed a significantly positive correlation(r 2 =0.822,P<0.05).The expression of AQP4 mRNA in Müller cells was increased by VEGF.The expression of AQP4 mRNA was significantly decreased by Avastin as compared with the control group.It is suggested that Avastin can decrease the expression of AQP4 mRNA in human Müller cells under chemical hypoxic conditions partially via VEGF path,which may be one of the mechanisms of Avastin treating retinal edema.展开更多
目的:探讨加味桃红四物汤(MTSD)对视网膜Müller细胞rMC-1缺氧损伤的保护作用。方法:用加味桃红四物汤含药血清干预缺氧条件下rMC-1细胞,随机分为正常对照组(21%O_(2))、缺氧模型组(1%O_(2))、含药血清低(1%O_(2)+5%含药血清)、中(1...目的:探讨加味桃红四物汤(MTSD)对视网膜Müller细胞rMC-1缺氧损伤的保护作用。方法:用加味桃红四物汤含药血清干预缺氧条件下rMC-1细胞,随机分为正常对照组(21%O_(2))、缺氧模型组(1%O_(2))、含药血清低(1%O_(2)+5%含药血清)、中(1%O_(2)+10%含药血清)、高剂量组(1%O_(2)+15%含药血清),CCK-8法检测细胞的活力,ELISA法检测血管内皮生长因子(VEGF)和色素上皮衍生因子(PEDF)分泌,Western blot检测磷酸化转录激活因子3(p-STAT3)、转录激活因子3(STAT3)和缺氧诱导因子-1α(HIF-1α)的蛋白表达,Real time PCR检测VEGF、PEDF、STAT3和HIF-1α的基因表达。结果:在1%O_(2)条件下培养48h,rMC-1细胞活力较正常对照组明显受到抑制(P<0.05),加味桃红四物汤含药血清低、中剂量组均可以改善rMC-1细胞缺氧48h的细胞存活率(P<0.05),而高剂量组无改善作用(P>0.05)。加味桃红四物汤含药血清低、中剂量组均可减少缺氧条件下rMC-1细胞上清液VEGF的蛋白表达量(P<0.05),但不能增加PEDF的蛋白含量(P>0.05),对p-STAT3和HIF-1α在蛋白水平均有下调作用(P<0.05),且低剂量组抑制作用优于中剂量(P<0.05)。加味桃红四物汤含药血清中剂量组对缺氧后rMC-1细胞STAT3的蛋白表达有上调作用(P<0.05)。加味桃红四物汤含药血清低、中剂量组对缺氧后rMC-1细胞VEGF基因表达均有下调作用(P<0.05),对PEDF基因表达均有上调作用(P<0.05),且低剂量组优于中剂量(P<0.05);并且加味桃红四物汤含药血清低剂量可下调缺氧后STAT3和HIF-1α的基因表达(P<0.05)。结论:加味桃红四物汤含药血清可能通过抑制STAT3/HIF-1α通路,下调缺氧诱导的视网膜Müller细胞rMC-1的VEGF蛋白和基因表达,上调PEDF基因表达,减轻该细胞的缺氧损伤。展开更多
In the central nervous system(CNS),three types of myelin-associated inhibitors(MAIs) have major inhibitory effects on nerve regeneration.They include Nogo-A,myelin-associated glycoprotein,and oligodendrocyte-myelin gl...In the central nervous system(CNS),three types of myelin-associated inhibitors(MAIs) have major inhibitory effects on nerve regeneration.They include Nogo-A,myelin-associated glycoprotein,and oligodendrocyte-myelin glycoprotein.MAIs possess two co-receptors,Nogo receptor(NgR) and paired immunoglobulin-like receptor B(PirB).Previous studies have confirmed that the inhibition of NgR only results in a modest increase in regeneration in the CNS;however,the inhibitory effects of PirB with regard to nerve regeneration after binding to MAIs remain controversial.In this study,we demonstrated that PirB is expressed in primary cultures of retinal ganglion cells(RGCs),and the inhibitory effects of the three MAIs on the growth of RGC neurites are not significantly decreased after direct PirB knockdown using adenovirus PirB shRNA.Interestingly,we found that retinal Müller cells expressed PirB and that its knockdown enhanced the regeneration of co-cultured RGC neurites.PirB knockdown also activated the JAK/Stat3 signaling pathway in Müller cells and upregulated ciliary neurotrophic factor levels.These findings indicate that PirB plays a novel role in retinal Müller cells and that its action in these cells may indirectly affect the growth of RGC neurites.The results also reveal that PirB in Müller cells affects RGC neurite regeneration.Our findings provide a novel basis for the use of PirB as a target molecule to promote nerve regeneration.展开更多
Elevated intraocular pressure(IOP)is one of the causes of retinal ischemia/reperfusion injury,which results in NRP3 inflammasome activation and leads to visual damage.Homerla is repo rted to play a protective role in ...Elevated intraocular pressure(IOP)is one of the causes of retinal ischemia/reperfusion injury,which results in NRP3 inflammasome activation and leads to visual damage.Homerla is repo rted to play a protective role in neuroinflammation in the cerebrum.However,the effects of Homerla on NLRP3inflammasomes in retinal ischemia/reperfusion injury caused by elevated IOP remain unknown.In our study,animal models we re constructed using C57BL/6J and Homer1^(flox/-)/Homerla^(+/-)/Nestin-Cre^(+/-)mice with elevated IOP-induced retinal ischemia/repe rfusion injury.For in vitro expe riments,the oxygen-glucose deprivation/repe rfusion injury model was constructed with M uller cells.We found that Homerla ove rexpression amelio rated the decreases in retinal thickness and Muller cell viability after ischemia/reperfusion injury.Furthermore,Homerla knockdown promoted NF-κB P65^(Ser536)activation via caspase-8,NF-κB P65 nuclear translocation,NLRP3 inflammasome formation,and the production and processing of interleukin-1βand inte rleukin-18.The opposite results we re observed with Homerla ove rexpression.Finally,the combined administration of Homerla protein and JSH-23 significantly inhibited the reduction in retinal thickness in Homer1^(flox/-)Homer1a^(+/-)/Nestin-Cre^(+/-)mice and apoptosis in M uller cells after ischemia/reperfusion injury.Taken together,these studies demonstrate that Homer1a exerts protective effects on retinal tissue and M uller cells via the caspase-8/NF-KB P65/NLRP3 pathway after I/R injury.展开更多
基金supported by the Guangdong Grant Key Technologies for Treatment of Brain Disorders,China,No. 2018B030332001 (to GC)the Guangzhou Key Projects of Brain Science and Brain-Like Intelligence Technology,No. 20200730009 (to YX)the Guangdong Basic and Applied Basic Research Foundation,No. 2020A1515110898 (to WYC)。
文摘The onset of retinal degenerative disease is often associated with neuronal loss. Therefore, how to regenerate new neurons to restore vision is an important issue. NeuroD1 is a neural transcription factor with the ability to reprogram brain astrocytes into neurons in vivo. Here, we demonstrate that in adult mice, NeuroD1 can reprogram Müller cells, the principal glial cell type in the retina, to become retinal neurons. Most strikingly, ectopic expression of NeuroD1 using two different viral vectors converted Müller cells into different cell types. Specifically, AAV7 m8 GFAP681::GFP-ND1 converted Müller cells into inner retinal neurons, including amacrine cells and ganglion cells. In contrast, AAV9 GFAP104::ND1-GFP converted Müller cells into outer retinal neurons such as photoreceptors and horizontal cells, with higher conversion efficiency. Furthermore, we demonstrate that Müller cell conversion induced by AAV9 GFAP104::ND1-GFP displayed clear dose-and time-dependence. These results indicate that Müller cells in adult mice are highly plastic and can be reprogrammed into various subtypes of retinal neurons.
基金Supported by Shaanxi Province Science and Technology Research and Development Program (No. 2012K16-06-05)
文摘AIM: To investigate if pigment epithelium-derived factor(PEDF) has any protective effect on the retinal Müller cells of Sprague-Dawley rats suffering from diabetes mellitus.METHODS: Sixty Sprague-Dawley rats were randomly divided into a negative control group, a group receiving0.1 μg/μL PEDF, another group receiving 0.2 μg/μL PEDF,and a group receiving balanced salt solution(BSS). Rats in both the PEDF and BSS groups were treated intravitreally based on previously established diabetic models. After 4wk of treatment, morphological alterations of Müller cells and protein expression of glutamine synthase(GS) and glial fibrillary acidic protein(GFAP)were analyzed.RESULTS:PEDFateither0.1μg/μLor0.2μg/μLsignificantly improved the structures of both nuclei and organelles of Müller cells compared to the BSS-treated group.Expression of GS was significantly higher in the 0.2 μg/μL PEDF group than that in the BSS group(P =0.012), but expression of GFAP was significantly lower in the 0.2 μg/μL PEDF group than that in the BSS group(P =0.000);however, there were no significant differences in expression of these proteins between the 0.1 μg/μL PEDF group and the BSS group(P =0.608, P =0.152). CONCLUSION: PEDF protects the morphological ultrastructure of Müller cells, improves the expression of glutamate synthase and prevents cell gliosis.
文摘Pathophysiological explanations for metamorphopsia associated with retinal pathologies generally focus on photoreceptor organization disruption. However, the retinal microarchitecture is complicated, and we hypothesize that other retinal cells may also be involved. Metamorphopsia has been widely studied in eyes with epiretinal membranes and we revisit the idea that Müller cell displacement causes retinal macropsia. A Pub Med query and related article search for the macula ultrastructure under normal and pathological conditions revealed an enormous amount of information, particularly ultrahigh definition optical coherence tomography and other retinal imaging modality studies. Findings of these imaging studies support our hypothesis that Müller cells, and not cone photoreceptors, are primarily responsible for macropsia in eyes with epiretinal membranes. More specifically, we conclude that displacement of Müller cell endfeet, and not photoreceptor cones, is a more likely the explanation for retinal macropsia associated with epiretinal membranes.
基金supported by the grants from Lion's Foundation Grant and Bright Focus Foundation(to KSC)the National Natural Science Foundation of China, No.81600727(to RLZ)。
文摘Müller cells(MC) are considered dormant retinal progenitor cells in mammals.Previous studies demonstrated ephrin-As act as negative regulators of neural progenitor cells in the retina and brain.It remains unclear whether the lack of ephrin-A2/A3 is sufficient to promote the neurogenic potential of MC.Here we investigated whether the MC is the primary retinal cell type expressing ephrin-A2/A3 and their role on the neurogenic potential of Müller cells.In this study, we showed that ephrin-A2/A3 and their receptor EphA4 were expressed in retina and especially enriched in MC.The level of ephrin As/EphA4 expression increased as the retina matured that is correlated with the reduced proliferative and progenitor cell potential of MC.Next, we investigated the proliferation in primary MC cultures isolated from wild-type and A2~(–/–) A3~(–/–) mice by 5-ethynyl-2′-deoxyuridine(EdU) incorporation.We detected a significant increase of EdU~+ cells in MC derived from A2~(–/–) A3~(–/–) mice.Next, we investigated the role of ephrin-A2/A3 in mice undergoing photoreceptor degeneration such as Rhodopsin knockout(Rho~(–/–)) mice.To further evaluate the role of ephrin-A2/A3 in MC proliferation in vivo, EdU was injected intraperitoneally to adult wild-type, A2~(–/–) A3~(–/–), Rho~(–/–) and Rho~(–/–) A2~(–/–) A3~(–/–) mice and the numbers of EdU~+ cells distributed among different layers of the retina.Ephrin As/EphA4 expression was upregulated in the retina of Rho~(–/–) mice compared to the wild-type mice.In addition, cultured MC derived from ephrin-A2~(–/–) A3~(–/–) mice also expressed higher levels of progenitor cell markers and exhibited higher proliferation potential than those from wild-type mice.Interestingly, we detected a significant increase of EdU~+ cells in the retinas of adult ephrin-A2~(–/–) A3~(–/–) mice mainly in the inner nuclear layer;and these EdU~+ cells were co-localized with MC marker, cellular retinaldehyde-binding protein, suggesting some proliferating cells are from MC.In Rhodopsin knockout mice(Rho~(–/–) A2~(–/–) A3~(–/–) mice), a significantly greater amount of EdU~+ cells were located in the ciliary body, retina and RPE than that of Rho~(–/–) mice.Comparing between 6 and 12 weeks old Rho~(–/–) A2~(–/–) A3~(–/–) mice, we recorded more EdU~+ cells in the outer nuclear layer in the 12-week-old mice undergoing severe retinal degeneration.Taken together, Ephrin-A2/A3 are negative regulators of the proliferative and neurogenic potentials of MC.Absence of ephrin-A2/A3 promotes the migration of proliferating cells into the outer nuclear layer and may lead to retinal cell regeneration.All experimental procedures were approved by the Animal Care and Use Committee at Schepens Eye Research Institute, USA(approval No.S-353-0715) on October 24, 2012.
基金National Natural Science Foundation of China(No. 30600694)
文摘AIM: To investigate the effect of protein kinase C (PKC) on transforming growth factor-β2 (TGFβ2) and dopamine in retinal Müller cells of guinea pig myopic eye. METHODS: Myopia was induced by translucent goggles in guinea pig, whose retinal Müller cells were cultured using the enzyme-digesting method. Retinal Müller cells were divided into 5 groups: normal control, myopia, myopia plus GF109203X, myopia plus PMA, myopia plus DMSO. PKC activities were detected by the non-radioactive methods. TGFβ2 and tyrosine hydroxylase (TH) proteins were analyzed by Western Blotting in retinal Müller cells. Dopamine was determined by the high-performance liquid chromatography- electrochemical detection in suspensions. RESULTS: After 14 days deprived, the occluded eyes became myopic with ocular axle elongating. Müller cells of guinea pigs were obtained using enzyme digestion. Compared with normal control group, the increase in PKC activity and the up-regulation in TGFβ2 expression were found in retinal Müller cells of myopic eyes, with the decrease of TH and dopamine content (P <0.05). After PKC activated by PMA, TGFβ2 and TH content were up-regulated with the increase of dopamine content (P <0.05). While the PKC activities was inhibited by GF109203X, proteins of TGFβ2 and TH were down-regulated in the myopic eyes, with the decrease of dopamine content (P <0.05). CONCLUSION: TGFβ2 and dopamine are modulated by PKC in Müller cells of the myopic eyes in guinea pig.
基金National Natural Science Foundation of China (No.31140072)Doctoral Scientific Starting Foundation of Liaoning Medical University (No.Y2012B005)
文摘AIM:To explore the effects and potential mechanisms of curcumin on retinal Müller cell in early diabetic rats.·METHODS:Diabetic rats were induced by a single intraperitoneal injection of streptozotocin(STZ).Male Sprague-Dawley(SD) rats were randomly assigned into 4groups:control group(nave SD rats administered with a single intraperitoneal injection of citric buffer),diabetic group(STZ-diabetic rats),dimethyl sulfoxide(DMSO)group(diabetic rats intraperitoneally administered with mixture of DMSO and normal saline,once a day) and curcumin group(diabetic rats intraperitoneally administered with curcumin,80mg/kg,once a day).Three months after diabetes onset,malondialdehyde(MDA,indication of oxidative stress level) and reduced glutathione(GSH) in retina were detected with kits,glial fibrillary acidic protein(GFAP) in retina was revealed by immunohistochemistry and Western blot,and retinal glutamine synthetase(GS) were observed by Western blot.·RESULTS:Compared with control group,retinal MDA was increased,and GSH was decreased in diabetic and DMSO groups(P <0.05,respectively).While,retinal MDA and GSH in curcumin group showed no difference compared with control group(P >0.05).Furthermore,upregulation of retinal GFAP and down-regulation of retinal GS were detected in diabetic and DMSO groups,and no alteration could be observed in curcumin group revealed with Western blot.Compared with control group,retinal Müller cells showed significant increase in GFAP immunochemistry staining in diabetic and DMSO groups.Moreover,GFAP-positive staining was decreased in curcumin group compared with diabetic group.·CONCLUSION:Curcumin inhibits diabetic retinal oxidative stress,protects Müller cell,and prevents thedown-regulation of GS in diabetic retina.Therefore,curcumin has a therapeutic potential in the treatment of diabetic retinopathy(DR).
文摘AIM: To determine the effect of pirfenidone on the activated human Müller cells by platelet-derived growth factor-BB(PDGF-BB). METHODS: The primary human Müller cells were separated from retinal tissues and established the pathogenic model by stimulated with PDGF-BB. The Müller cells behaviour of normal group and the model group was measured by MTT assay, Trypan blue assay, cell migration assay, and collagen contraction assay. The expression of transforming growth factor(TGF)-β1,-β2, and pigment epithelium-derived factor(PEDF) was estimated with realtime polymerase chain reaction(PCR), Western blot and immunofluorescence analyses. RESULTS: A pathogenic/proliferative model of Müller cells was established by stimulating normal cultured Müller cells with 10 ng/mL PDGF-BB for 48 h. After treated with 0.2 and 0.3 mg/mL pirfenidone, the proliferation, migration and collagen contraction was statistically significantly depressed in the model group compared with the normal groups. The expression levels of TGF-β1 and TGF-β2 were significantly down-regulated, while the PEDF expression was significantly up-regulated after treated with 0.2 and 0.3 mg/mL pirfenidone in the model group. CONCLUSION: Pirfenidone effectively suppress the proliferation, migration and collagen contraction of the human Müller cells stimulated with PDGF-BB through down-regulation of TGF-β1/TGF-β2 and up-regulation of PEDF.
基金financially supported by the Scientific and Technological Project of Shaanxi Province of China,No.2016SF-010
文摘Rho kinase(ROCK) was the first downstream Rho effector found to mediate Rho A-induced actin cytoskeletal changes through effects on myosin light chain phosphorylation. There is abundant evidence that the ROCK pathway participates in the pathogenesis of retinal endothelial injury and proliferative epiretinal membrane traction. In this study, we investigated the effect of the ROCK pathway inhibitor Y-27632 on retinal Müller cells subjected to hypoxia or oxidative stress. Müller cells were subjected to hypoxia or oxidative stress by exposure to CoCl_2 or H_2 O_2. After a 24-hour treatment with Y-27632, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was used to assess the survival of Müller cells. Hoechst 33258 was used to detect apoptosis, while 2′,7′-dichlorodihydrofluorescein diacetate was used to measure reactive oxygen species generation. A transwell chamber system was used to examine the migration ability of Müller cells. Western blot assay was used to detect the expression levels of α-smooth muscle actin, glutamine synthetase and vimentin. After treatment with Y-27632, Müller cells subjected to hypoxia or oxidative stress exhibited a morphology similar to control cells. Y-27632 reduced apoptosis, α-smooth muscle actin expression and reactive oxygen species generation under oxidative stress, and it reduced cell migration under hypoxia. Y-27632 also upregulated glutamine synthetase expression under hypoxia but did not impact vimentin expression. These findings suggest that Y-27632 protects Müller cells against cellular injury caused by oxidative stress and hypoxia by inhibiting the ROCK pathway.
基金Supported by the National Natural Science Foundation of China(No. 30571570)
文摘Objective:To detect the expression of glial fibrillary acid protein (GFAP) and taurine trans- porter (TauT) in the retinal Müller cells in high glucose culture with taurine and to explore the influence of glucose on the taurine transporting,and the possible protective effects of taurine on Müller cells in early diabetic retinopathy.Methods.The Müller cells from the rat retina were cultured in high glucose,and GFAP and TauT expressions were detected in the cells treated with different doses of taurine by immuocy- tochemical fluorescein staining and Western blotting.Results:High glucose enhanced the expression of GFAP and decreased the expression of TauT in Müller cells.Taurine decreased the up-regulation of GFAP in the cells which was induced by high glucoses 0.1-10mmol/L taurine increased the expression of TauT in Müller cells.Conclusion:Taurine can inhibit the changes in Müller cell resulted from high glucose.
文摘The aim of this study was to investigate the effects of Avastin on aquaporin4(AQP4) expression in human retinal Müller cells in vitro under hypoxia,so as to explore the mechanism of Avastin treating retinal edema.The human Müller cells were cultured using the enzymatic digestion method.Müller cells were identified under the transmission electron microscopy and by using immunofluorescence staining.By using semi-quantitative reverse transcription polymerase chain reaction(RT-PCR),the expression of AQP4 mRNA and VEGF mRNA in Müller cells cultured with 500 μmol/L CoCl 2 for 0,3,6,12 and 24 h,and with 0,100,300,500 and 700 μmol/L CoCl 2 for 24 h was detected.The expression of AQP4 mRNA in Müller cells cultured with 50 ng/mL exogenous vascular endothelial growth factor(VEGF) for 0,0.5,1,2 and 4 h,and with 0,25,50 and 75 ng/mL VEGF for 24 h was detected.Amplified cDNA products of AQP4 mRNA in Müller cells cultured with 500 μmol/L CoCl 2 and 200 μg/mL Avastin for 24 h were detected.The results showed that more than 95% cells displayed positive immunofluorescence reaction.Characteristic 8-10 nm intracellular filaments could be seen in the cytoplasm under the transmission electron microscopy.In the CoCl 2 experimental groups,the expression of AQP4 mRNA and VEGF mRNA in Müller cells was increased as compared with the control group.Alteration of AQP4 mRNA and VEGF mRNA levels showed a significantly positive correlation(r 2 =0.822,P<0.05).The expression of AQP4 mRNA in Müller cells was increased by VEGF.The expression of AQP4 mRNA was significantly decreased by Avastin as compared with the control group.It is suggested that Avastin can decrease the expression of AQP4 mRNA in human Müller cells under chemical hypoxic conditions partially via VEGF path,which may be one of the mechanisms of Avastin treating retinal edema.
文摘目的:探讨加味桃红四物汤(MTSD)对视网膜Müller细胞rMC-1缺氧损伤的保护作用。方法:用加味桃红四物汤含药血清干预缺氧条件下rMC-1细胞,随机分为正常对照组(21%O_(2))、缺氧模型组(1%O_(2))、含药血清低(1%O_(2)+5%含药血清)、中(1%O_(2)+10%含药血清)、高剂量组(1%O_(2)+15%含药血清),CCK-8法检测细胞的活力,ELISA法检测血管内皮生长因子(VEGF)和色素上皮衍生因子(PEDF)分泌,Western blot检测磷酸化转录激活因子3(p-STAT3)、转录激活因子3(STAT3)和缺氧诱导因子-1α(HIF-1α)的蛋白表达,Real time PCR检测VEGF、PEDF、STAT3和HIF-1α的基因表达。结果:在1%O_(2)条件下培养48h,rMC-1细胞活力较正常对照组明显受到抑制(P<0.05),加味桃红四物汤含药血清低、中剂量组均可以改善rMC-1细胞缺氧48h的细胞存活率(P<0.05),而高剂量组无改善作用(P>0.05)。加味桃红四物汤含药血清低、中剂量组均可减少缺氧条件下rMC-1细胞上清液VEGF的蛋白表达量(P<0.05),但不能增加PEDF的蛋白含量(P>0.05),对p-STAT3和HIF-1α在蛋白水平均有下调作用(P<0.05),且低剂量组抑制作用优于中剂量(P<0.05)。加味桃红四物汤含药血清中剂量组对缺氧后rMC-1细胞STAT3的蛋白表达有上调作用(P<0.05)。加味桃红四物汤含药血清低、中剂量组对缺氧后rMC-1细胞VEGF基因表达均有下调作用(P<0.05),对PEDF基因表达均有上调作用(P<0.05),且低剂量组优于中剂量(P<0.05);并且加味桃红四物汤含药血清低剂量可下调缺氧后STAT3和HIF-1α的基因表达(P<0.05)。结论:加味桃红四物汤含药血清可能通过抑制STAT3/HIF-1α通路,下调缺氧诱导的视网膜Müller细胞rMC-1的VEGF蛋白和基因表达,上调PEDF基因表达,减轻该细胞的缺氧损伤。
基金supported by the National Natural Science Foundation of China (81470630)。
文摘In the central nervous system(CNS),three types of myelin-associated inhibitors(MAIs) have major inhibitory effects on nerve regeneration.They include Nogo-A,myelin-associated glycoprotein,and oligodendrocyte-myelin glycoprotein.MAIs possess two co-receptors,Nogo receptor(NgR) and paired immunoglobulin-like receptor B(PirB).Previous studies have confirmed that the inhibition of NgR only results in a modest increase in regeneration in the CNS;however,the inhibitory effects of PirB with regard to nerve regeneration after binding to MAIs remain controversial.In this study,we demonstrated that PirB is expressed in primary cultures of retinal ganglion cells(RGCs),and the inhibitory effects of the three MAIs on the growth of RGC neurites are not significantly decreased after direct PirB knockdown using adenovirus PirB shRNA.Interestingly,we found that retinal Müller cells expressed PirB and that its knockdown enhanced the regeneration of co-cultured RGC neurites.PirB knockdown also activated the JAK/Stat3 signaling pathway in Müller cells and upregulated ciliary neurotrophic factor levels.These findings indicate that PirB plays a novel role in retinal Müller cells and that its action in these cells may indirectly affect the growth of RGC neurites.The results also reveal that PirB in Müller cells affects RGC neurite regeneration.Our findings provide a novel basis for the use of PirB as a target molecule to promote nerve regeneration.
基金supported by the Youth Development Project of Air Force Military Medical University,No.21 QNPY072Key Project of Shaanxi Provincial Natural Science Basic Research Program,No.2023-JC-ZD-48(both to FF)。
文摘Elevated intraocular pressure(IOP)is one of the causes of retinal ischemia/reperfusion injury,which results in NRP3 inflammasome activation and leads to visual damage.Homerla is repo rted to play a protective role in neuroinflammation in the cerebrum.However,the effects of Homerla on NLRP3inflammasomes in retinal ischemia/reperfusion injury caused by elevated IOP remain unknown.In our study,animal models we re constructed using C57BL/6J and Homer1^(flox/-)/Homerla^(+/-)/Nestin-Cre^(+/-)mice with elevated IOP-induced retinal ischemia/repe rfusion injury.For in vitro expe riments,the oxygen-glucose deprivation/repe rfusion injury model was constructed with M uller cells.We found that Homerla ove rexpression amelio rated the decreases in retinal thickness and Muller cell viability after ischemia/reperfusion injury.Furthermore,Homerla knockdown promoted NF-κB P65^(Ser536)activation via caspase-8,NF-κB P65 nuclear translocation,NLRP3 inflammasome formation,and the production and processing of interleukin-1βand inte rleukin-18.The opposite results we re observed with Homerla ove rexpression.Finally,the combined administration of Homerla protein and JSH-23 significantly inhibited the reduction in retinal thickness in Homer1^(flox/-)Homer1a^(+/-)/Nestin-Cre^(+/-)mice and apoptosis in M uller cells after ischemia/reperfusion injury.Taken together,these studies demonstrate that Homer1a exerts protective effects on retinal tissue and M uller cells via the caspase-8/NF-KB P65/NLRP3 pathway after I/R injury.
