AIM:To investigate the involvement of pericyte-Müller glia interaction in retinal damage repair and assess the influence of suppressing the platelet-derived growth factor receptorβ(PDGFRβ)signaling pathway in r...AIM:To investigate the involvement of pericyte-Müller glia interaction in retinal damage repair and assess the influence of suppressing the platelet-derived growth factor receptorβ(PDGFRβ)signaling pathway in retinal pericytes on photoreceptor loss and Müller glial response.METHODS:Sprague-Dawley rats were exposed to intense light to induce retinal injury.Neutralizing antibody against PDGFRβwere deployed to block the signaling pathway in retinal pericytes through intravitreal injection.Retinal histology and Müller glial reaction were assessed following light injury.In vitro,normal and PDGFRβ-blocked retinal pericytes were cocultured with Müller cell line(rMC-1)to examine morphological and protein expression changes upon supplementation with light-injured supernatants of homogenized retinas(SHRs).RESULTS:PDGFRβblockage 24h prior to intense light exposure resulted in a significant exacerbation of photoreceptor loss.The upregulation of GFAP and p-STAT3,observed after intense light exposure,was significantly inhibited in the PDGFRβblockage group.Fur ther upregulation of cytokines monocyte chemoattractant protein 1(MCP-1)and interleukin-1β(IL-1β)was also observed following PDGFRβinhibition.In the in vitro coculture system,the addition of light-injured SHRs induced pericyte deformation and upregulation of proliferating cell nuclear antigen(PCNA)expression,while Müller cells exhibited neuron-like morphology and expressed Nestin.However,PDGFRβblockage in retinal pericytes abolished these cellular responses to light-induced damage,consistent with the in vivo PDGFRβblockage findings.CONCLUSION:Pericyte-Müller glia interaction plays a potential role in the endogenous repair process of retinal injury.Impairment of this interaction exacerbates photoreceptor degeneration in light-induced retinal injury.展开更多
Müller glia,as prominent glial cells within the retina,plays a significant role in maintaining retinal homeostasis in both healthy and diseased states.In lower vertebrates like zebrafish,these cells assume respon...Müller glia,as prominent glial cells within the retina,plays a significant role in maintaining retinal homeostasis in both healthy and diseased states.In lower vertebrates like zebrafish,these cells assume responsibility for spontaneous retinal regeneration,wherein endogenous Müller glia undergo proliferation,transform into Müller glia-derived progenitor cells,and subsequently regenerate the entire retina with restored functionality.Conversely,Müller glia in the mouse and human retina exhibit limited neural reprogramming.Müller glia reprogramming is thus a promising strategy for treating neurodegenerative ocular disorders.Müller glia reprogramming in mice has been accomplished with remarkable success,through various technologies.Advancements in molecular,genetic,epigenetic,morphological,and physiological evaluations have made it easier to document and investigate the Müller glia programming process in mice.Nevertheless,there remain issues that hinder improving reprogramming efficiency and maturity.Thus,understanding the reprogramming mechanism is crucial toward exploring factors that will improve Müller glia reprogramming efficiency,and for developing novel Müller glia reprogramming strategies.This review describes recent progress in relatively successful Müller glia reprogramming strategies.It also provides a basis for developing new Müller glia reprogramming strategies in mice,including epigenetic remodeling,metabolic modulation,immune regulation,chemical small-molecules regulation,extracellular matrix remodeling,and cell-cell fusion,to achieve Müller glia reprogramming in mice.展开更多
A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to ...A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to examine the pathological changes and molecular mechanisms of retinal damage under microgravity.After 4 weeks of tail suspension,there were no notable alterations in retinal function and morphology,while after 8 weeks of tail suspension,significant reductions in retinal function were observed,and the outer nuclear layer was thinner,with abundant apoptotic cells.To investigate the mechanism underlying the degenerative changes that occurred in the outer nuclear layer of the retina,proteomics was used to analyze differentially expressed proteins in rat retinas after 8 weeks of tail suspension.The results showed that the expression levels of fibroblast growth factor 2(also known as basic fibroblast growth factor)and glial fibrillary acidic protein,which are closely related to Müller cell activation,were significantly upregulated.In addition,Müller cell regeneration and Müller cell gliosis were observed after 4 and 8 weeks,respectively,of simulated weightlessness.These findings indicate that Müller cells play an important regulatory role in retinal outer nuclear layer degeneration during weightlessness.展开更多
This paper presents an efficient numerical technique for solving multi-term linear systems of fractional ordinary differential equations(FODEs)which have been widely used in modeling various phenomena in engineering a...This paper presents an efficient numerical technique for solving multi-term linear systems of fractional ordinary differential equations(FODEs)which have been widely used in modeling various phenomena in engineering and science.An approximate solution of the system is sought in the formof the finite series over the Müntz polynomials.By using the collocation procedure in the time interval,one gets the linear algebraic system for the coefficient of the expansion which can be easily solved numerically by a standard procedure.This technique also serves as the basis for solving the time-fractional partial differential equations(PDEs).The modified radial basis functions are used for spatial approximation of the solution.The collocation in the solution domain transforms the equation into a system of fractional ordinary differential equations similar to the one mentioned above.Several examples have verified the performance of the proposed novel technique with high accuracy and efficiency.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
The transcription factor Sox11 plays important roles in retinal neurogenesis during vertebrate eye development.However,its function in retina regeneration remains elusive.Here we report that Sox11 b,a zebrafish Sox11 ...The transcription factor Sox11 plays important roles in retinal neurogenesis during vertebrate eye development.However,its function in retina regeneration remains elusive.Here we report that Sox11 b,a zebrafish Sox11 homolog,regulates the migration and fate determination of Müller glia-derived progenitors(MGPCs)in an adult zebrafish model of mechanical retinal injury.Following a stab injury,the expression of Sox11 b was induced in proliferating MGPCs in the retina.Sox11 b knockdown did not affect MGPC formation at 4 days post-injury,although the nuclear morphology and subsequent radial migration of MGPCs were alte red.At 7 days post-injury,Sox11 b knockdown res ulted in an increased proportion of MGPCs in the inner retina and a decreased propo rtion of MGPCs in the outer nuclear layer,compared with controls.Furthermore,Sox11 b knockdown led to reduced photoreceptor regeneration,while it increased the numbe rs of newborn amacrines and retinal ganglion cells.Finally,quantitative polymerase chain reaction analysis revealed that Sox11 b regulated the expression of Notch signaling components in the retina,and Notch inhibition partially recapitulated the Sox11 b knockdown phenotype,indicating that Notch signaling functions downstream of Sox11 b.Our findings imply that Sox11 b plays key roles in MGPC migration and fate determination during retina regeneration in zebrafish,which may have critical im plications for future explorations of retinal repair in mammals.展开更多
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
The majority of inherited retinal degenerative diseases and dry age-related macular degeneration are characterized by decay of the outer retina and photoreceptors,which leads to progressive loss of vision.The inner re...The majority of inherited retinal degenerative diseases and dry age-related macular degeneration are characterized by decay of the outer retina and photoreceptors,which leads to progressive loss of vision.The inner retina,including second-and third-order retinal neurons,also shows aberrant structural changes at all stages of degeneration.Müller glia,the major glial cells maintain retinal homeostasis,activating and rearranging immediately in response to photoreceptor stress.These phenomena are collectively known as retinal remodeling and are anatomically well described,but their impact on visual function is less well characterized.Retinal remodeling has traditionally been considered a detrimental chain of events that decreases visual function.However,emerging evidence from functional assays suggests that remodeling could also be a part of a survival mechanism wherein the inner retina responds plastically to outer retinal degeneration.The visual system’s first synapses between the photoreceptors and bipolar cells undergo rewiring and functionally compensate to maintain normal signal output to the brain.Distinct classes of retinal ganglion cells remain even after the massive loss of photoreceptors.Müller glia possess the regenerative potential for retinal recovery and possibly exert adaptive transcriptional changes in response to neuronal loss.These types of homeostatic changes could potentially explain the well-maintained visual function observed in patients with inherited retinal degenerative diseases who display prominent anatomic retinal pathology.This review will focus on our current understanding of retinal neuronal and Müller glial adaptation for the potential preservation of retinal activity during photoreceptor degeneration.Targeting retinal self-compensatory responses could help generate universal strategies to delay sensory disease progression.展开更多
基金Supported by National Natural Science Foundation of China(No.81900862)。
文摘AIM:To investigate the involvement of pericyte-Müller glia interaction in retinal damage repair and assess the influence of suppressing the platelet-derived growth factor receptorβ(PDGFRβ)signaling pathway in retinal pericytes on photoreceptor loss and Müller glial response.METHODS:Sprague-Dawley rats were exposed to intense light to induce retinal injury.Neutralizing antibody against PDGFRβwere deployed to block the signaling pathway in retinal pericytes through intravitreal injection.Retinal histology and Müller glial reaction were assessed following light injury.In vitro,normal and PDGFRβ-blocked retinal pericytes were cocultured with Müller cell line(rMC-1)to examine morphological and protein expression changes upon supplementation with light-injured supernatants of homogenized retinas(SHRs).RESULTS:PDGFRβblockage 24h prior to intense light exposure resulted in a significant exacerbation of photoreceptor loss.The upregulation of GFAP and p-STAT3,observed after intense light exposure,was significantly inhibited in the PDGFRβblockage group.Fur ther upregulation of cytokines monocyte chemoattractant protein 1(MCP-1)and interleukin-1β(IL-1β)was also observed following PDGFRβinhibition.In the in vitro coculture system,the addition of light-injured SHRs induced pericyte deformation and upregulation of proliferating cell nuclear antigen(PCNA)expression,while Müller cells exhibited neuron-like morphology and expressed Nestin.However,PDGFRβblockage in retinal pericytes abolished these cellular responses to light-induced damage,consistent with the in vivo PDGFRβblockage findings.CONCLUSION:Pericyte-Müller glia interaction plays a potential role in the endogenous repair process of retinal injury.Impairment of this interaction exacerbates photoreceptor degeneration in light-induced retinal injury.
基金supported by the National Natural Science Foundation of China,No.31930068National Key Research and Development Program of China,Nos.2018YFA0107302 and 2021YFA1101203(all to HX).
文摘Müller glia,as prominent glial cells within the retina,plays a significant role in maintaining retinal homeostasis in both healthy and diseased states.In lower vertebrates like zebrafish,these cells assume responsibility for spontaneous retinal regeneration,wherein endogenous Müller glia undergo proliferation,transform into Müller glia-derived progenitor cells,and subsequently regenerate the entire retina with restored functionality.Conversely,Müller glia in the mouse and human retina exhibit limited neural reprogramming.Müller glia reprogramming is thus a promising strategy for treating neurodegenerative ocular disorders.Müller glia reprogramming in mice has been accomplished with remarkable success,through various technologies.Advancements in molecular,genetic,epigenetic,morphological,and physiological evaluations have made it easier to document and investigate the Müller glia programming process in mice.Nevertheless,there remain issues that hinder improving reprogramming efficiency and maturity.Thus,understanding the reprogramming mechanism is crucial toward exploring factors that will improve Müller glia reprogramming efficiency,and for developing novel Müller glia reprogramming strategies.This review describes recent progress in relatively successful Müller glia reprogramming strategies.It also provides a basis for developing new Müller glia reprogramming strategies in mice,including epigenetic remodeling,metabolic modulation,immune regulation,chemical small-molecules regulation,extracellular matrix remodeling,and cell-cell fusion,to achieve Müller glia reprogramming in mice.
基金supported by the Army Laboratory Animal Foundation of China,No.SYDW[2020]22(to TC)the Shaanxi Provincial Key R&D Plan General Project of China,No.2022SF-236(to YM)the National Natural Science Foundation of China,No.82202070(to TC)。
文摘A microgravity environment has been shown to cause ocular damage and affect visual acuity,but the underlying mechanisms remain unclear.Therefore,we established an animal model of weightlessness via tail suspension to examine the pathological changes and molecular mechanisms of retinal damage under microgravity.After 4 weeks of tail suspension,there were no notable alterations in retinal function and morphology,while after 8 weeks of tail suspension,significant reductions in retinal function were observed,and the outer nuclear layer was thinner,with abundant apoptotic cells.To investigate the mechanism underlying the degenerative changes that occurred in the outer nuclear layer of the retina,proteomics was used to analyze differentially expressed proteins in rat retinas after 8 weeks of tail suspension.The results showed that the expression levels of fibroblast growth factor 2(also known as basic fibroblast growth factor)and glial fibrillary acidic protein,which are closely related to Müller cell activation,were significantly upregulated.In addition,Müller cell regeneration and Müller cell gliosis were observed after 4 and 8 weeks,respectively,of simulated weightlessness.These findings indicate that Müller cells play an important regulatory role in retinal outer nuclear layer degeneration during weightlessness.
基金funded by the National Key Research and Development Program of China(No.2021YFB2600704)the National Natural Science Foundation of China(No.52171272)the Significant Science and Technology Project of the Ministry of Water Resources of China(No.SKS-2022112).
文摘This paper presents an efficient numerical technique for solving multi-term linear systems of fractional ordinary differential equations(FODEs)which have been widely used in modeling various phenomena in engineering and science.An approximate solution of the system is sought in the formof the finite series over the Müntz polynomials.By using the collocation procedure in the time interval,one gets the linear algebraic system for the coefficient of the expansion which can be easily solved numerically by a standard procedure.This technique also serves as the basis for solving the time-fractional partial differential equations(PDEs).The modified radial basis functions are used for spatial approximation of the solution.The collocation in the solution domain transforms the equation into a system of fractional ordinary differential equations similar to the one mentioned above.Several examples have verified the performance of the proposed novel technique with high accuracy and efficiency.
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 Key Research and Development Project of China,Nos.2017YFA0104100(to JL),2017YFA0701304(to HX)National Natural Science Foundation of China Nos.81970820(to HX),31930068(to JL)。
文摘The transcription factor Sox11 plays important roles in retinal neurogenesis during vertebrate eye development.However,its function in retina regeneration remains elusive.Here we report that Sox11 b,a zebrafish Sox11 homolog,regulates the migration and fate determination of Müller glia-derived progenitors(MGPCs)in an adult zebrafish model of mechanical retinal injury.Following a stab injury,the expression of Sox11 b was induced in proliferating MGPCs in the retina.Sox11 b knockdown did not affect MGPC formation at 4 days post-injury,although the nuclear morphology and subsequent radial migration of MGPCs were alte red.At 7 days post-injury,Sox11 b knockdown res ulted in an increased proportion of MGPCs in the inner retina and a decreased propo rtion of MGPCs in the outer nuclear layer,compared with controls.Furthermore,Sox11 b knockdown led to reduced photoreceptor regeneration,while it increased the numbe rs of newborn amacrines and retinal ganglion cells.Finally,quantitative polymerase chain reaction analysis revealed that Sox11 b regulated the expression of Notch signaling components in the retina,and Notch inhibition partially recapitulated the Sox11 b knockdown phenotype,indicating that Notch signaling functions downstream of Sox11 b.Our findings imply that Sox11 b plays key roles in MGPC migration and fate determination during retina regeneration in zebrafish,which may have critical im plications for future explorations of retinal repair in mammals.
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 NIH R01EY032492Boston Children’s Hospital(OFD/BTREC/CTREC Faculty Career Development Grant 97906,Pilot Grant 92214,and Ophthalmology Foundation 85010)+5 种基金Mass Lions Eye Foundation 87820Blind Children’s Center 89282(to ZF)Academy of Finland grant 346295Finnish Eye and Tissue Bank FoundationRetina Registered Association(Finland)Sokeain Yst?v?t/De Blindas V?nner Registered Association(to HOL)。
文摘The majority of inherited retinal degenerative diseases and dry age-related macular degeneration are characterized by decay of the outer retina and photoreceptors,which leads to progressive loss of vision.The inner retina,including second-and third-order retinal neurons,also shows aberrant structural changes at all stages of degeneration.Müller glia,the major glial cells maintain retinal homeostasis,activating and rearranging immediately in response to photoreceptor stress.These phenomena are collectively known as retinal remodeling and are anatomically well described,but their impact on visual function is less well characterized.Retinal remodeling has traditionally been considered a detrimental chain of events that decreases visual function.However,emerging evidence from functional assays suggests that remodeling could also be a part of a survival mechanism wherein the inner retina responds plastically to outer retinal degeneration.The visual system’s first synapses between the photoreceptors and bipolar cells undergo rewiring and functionally compensate to maintain normal signal output to the brain.Distinct classes of retinal ganglion cells remain even after the massive loss of photoreceptors.Müller glia possess the regenerative potential for retinal recovery and possibly exert adaptive transcriptional changes in response to neuronal loss.These types of homeostatic changes could potentially explain the well-maintained visual function observed in patients with inherited retinal degenerative diseases who display prominent anatomic retinal pathology.This review will focus on our current understanding of retinal neuronal and Müller glial adaptation for the potential preservation of retinal activity during photoreceptor degeneration.Targeting retinal self-compensatory responses could help generate universal strategies to delay sensory disease progression.
