Downregulation of the inwardly rectifying potassium channel Kir4.1 is a key step for inducing retinal Müller cell activation and interaction with other glial cells,which is involved in retinal ganglion cell apopt...Downregulation of the inwardly rectifying potassium channel Kir4.1 is a key step for inducing retinal Müller cell activation and interaction with other glial cells,which is involved in retinal ganglion cell apoptosis in glaucoma.Modulation of Kir4.1 expression in Müller cells may therefore be a potential strategy for attenuating retinal ganglion cell damage in glaucoma.In this study,we identified seven predicted phosphorylation sites in Kir4.1 and constructed lentiviral expression systems expressing Kir4.1 mutated at each site to prevent phosphorylation.Following this,we treated Müller glial cells in vitro and in vivo with the m Glu R I agonist DHPG to induce Kir4.1 or Kir4.1 Tyr^(9)Asp overexpression.We found that both Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression inhibited activation of Müller glial cells.Subsequently,we established a rat model of chronic ocular hypertension by injecting microbeads into the anterior chamber and overexpressed Kir4.1 or Kir4.1 Tyr^(9)Asp in the eye,and observed similar results in Müller cells in vivo as those seen in vitro.Both Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression inhibited Müller cell activation,regulated the balance of Bax/Bcl-2,and reduced the m RNA and protein levels of pro-inflammatory factors,including interleukin-1βand tumor necrosis factor-α.Furthermore,we investigated the regulatory effects of Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression on the release of pro-inflammatory factors in a co-culture system of Müller glial cells and microglia.In this co-culture system,we observed elevated adenosine triphosphate concentrations in activated Müller cells,increased levels of translocator protein(a marker of microglial activation),and elevated interleukin-1βm RNA and protein levels in microglia induced by activated Müller cells.These changes could be reversed by Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression in Müller cells.Kir4.1 overexpression,but not Kir4.1 Tyr^(9)Asp overexpression,reduced the number of proliferative and migratory microglia induced by activated Müller cells.Collectively,these results suggest that the tyrosine residue at position nine in Kir4.1 may serve as a functional modulation site in the retina in an experimental model of glaucoma.Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression attenuated Müller cell activation,reduced ATP/P2X receptor–mediated interactions between glial cells,inhibited microglial activation,and decreased the synthesis and release of pro-inflammatory factors,consequently ameliorating retinal ganglion cell apoptosis in glaucoma.展开更多
Synaptic plasticity is essential for maintaining neuronal function in the central nervous system and serves as a critical indicator of the effects of neurodegenerative disease.Glaucoma directly impairs retinal ganglio...Synaptic plasticity is essential for maintaining neuronal function in the central nervous system and serves as a critical indicator of the effects of neurodegenerative disease.Glaucoma directly impairs retinal ganglion cells and their axons,leading to axonal transport dysfuntion,subsequently causing secondary damage to anterior or posterior ends of the visual system.Accordingly,recent evidence indicates that glaucoma is a degenerative disease of the central nervous system that causes damage throughout the visual pathway.However,the effects of glaucoma on synaptic plasticity in the primary visual cortex remain unclear.In this study,we established a mouse model of unilateral chronic ocular hypertension by injecting magnetic microbeads into the anterior chamber of one eye.We found that,after 4 weeks of chronic ocular hypertension,the neuronal somas were smaller in the superior colliculus and lateral geniculate body regions of the brain contralateral to the affected eye.This was accompanied by glial cell activation and increased expression of inflammatory factors.After 8 weeks of ocular hypertension,we observed a reduction in the number of excitatory and inhibitory synapses,dendritic spines,and activation of glial cells in the primary visual cortex contralateral to the affected eye.These findings suggest that glaucoma not only directly damages the retina but also induces alterations in synapses and dendritic spines in the primary visual cortex,providing new insights into the pathogenesis of glaucoma.展开更多
Neurodegenerative diseases account for a large and increasing health and economic burden worldwide.With an increasingly aged population,this burden is set to increase.Optic neuropathies make up a large proportion of n...Neurodegenerative diseases account for a large and increasing health and economic burden worldwide.With an increasingly aged population,this burden is set to increase.Optic neuropathies make up a large proportion of neurodegenerative diseases with glaucoma being highly prevalent.Glaucoma is characterized by the progressive dysfunction and loss of retinal ganglion cells and their axons which make up the optic nerve.It is the leading cause of irreversible vision loss and affects an estimated 80 million people.The mammalian central nervous system is non-regenerative and,once lost or injured,retinal ganglion cells cannot regenerate an axon into the optic nerve under basal conditions.Thus,strategies that provide neuroprotection to stressed,dysfunctional,or dying retinal ganglion cells are likely to be of high therapeutic and translational value.Advancing age,genetics,and elevated intraocular pressure are all major risk factors for glaucoma,however,all clinically available glaucoma treatments focus on intraocular pressure management and do not directly address the neurodegenerative component of glaucoma.展开更多
Glaucoma is characterized by chronic progressive optic nerve damage and retinal ganglion cell death.Although extensive research has been conducted on neuroprotection for retinal ganglion cells,there is still no treatm...Glaucoma is characterized by chronic progressive optic nerve damage and retinal ganglion cell death.Although extensive research has been conducted on neuroprotection for retinal ganglion cells,there is still no treatment for clinical use.Recent evidence shows that extracellular vesicles isolated from a variety of stem cells are efficacious in retinal ganglion cell neuroprotection.In this study,we tested the novel extracellular vesicle source of the retinal progenitor R-28 cell line in vitro and in vivo.We isolated and characterized extracellular vesicles from R-28 cells and tested their therapeutic efficacy in terms of retinal ganglion cell survival in vitro and in an in vivo glaucoma model,measuring retinal ganglion cell survival and preservation of their axons.Additionally,we tested extracellular vesicles for their neuroprotective capacity in retinal ganglion cells differentiated from human embryonic stem cells.Finally,we investigated miRNA changes in retinal ganglion cells with R-28 extracellular vesicle treatment,and predicted possible pathways that may be modulated.R-28 extracellular vesicles improved retinal ganglion cell survival but failed to preserve axons significantly.Moreover,the results also illustrated the neuroprotection of R-28 extracellular vesicles on human retinal ganglion cells.Finally,we also showed changes in hsa-miRNA-4443,hsa-miRNA-216a-5p,hsa-let-7e-5p,hsa-miRNA-374b-5p,hsa-miRNA-331-3p,and hsa-miRNA-421 expressions,which may have neuroprotective potential on retinal ganglion cell degeneration.This study will pave the way for miRNA and extracellular vesicle-based neuroprotective therapies for glaucoma.展开更多
Interaction between Müller cells and microglia aggravates neuroinflammation,resulting in retinal ganglion cell(RGC)death in glaucoma.Here,we investigated how tumor necrosis factor-alpha(TNF-α)produced by activat...Interaction between Müller cells and microglia aggravates neuroinflammation,resulting in retinal ganglion cell(RGC)death in glaucoma.Here,we investigated how tumor necrosis factor-alpha(TNF-α)produced by activated microglia mediates the crosstalk between Müller cells and microglia and impacts RGC injury in a chronic ocular hypertension(COH)glaucoma model.In COH retinas,elevated TNF-αinduced the activation of Müller cells and microglia,and recruited microglia to the ganglion cell layer.Co-culture with Müller cells enhanced TNF-α-induced microglial activation,migration,and proliferation.Both in vivo and in vitro experiments confirmed that chemokine C-C motif ligand 2(CCL2),primarily released from Müller cells,mediated the TNF-α-induced effects on microglia in COH retinas.Knockdown of CCL2 attenuated RGC damage and vision loss.Our results demonstrate that TNF-αreleased from microglia induces the secretion of CCL2 from Müller cells,thus inducing microglial activation and migration,exacerbating retinal neuroinflammation and RGC injury in glaucoma.展开更多
Globally,glaucoma stands as a primary cause of irreversible blindness,marked by intricate pathophysiological processes in which neuroinflammation plays a pivotal role.As the principal immune cells within the central n...Globally,glaucoma stands as a primary cause of irreversible blindness,marked by intricate pathophysiological processes in which neuroinflammation plays a pivotal role.As the principal immune cells within the central nervous system,microglia play a dual function in the progression of glaucoma.Under standard physiological states,microglia safeguard the retina by offering neurotrophic support and removing cellular debris.In the pathological progression of glaucoma,microglia become activated and release significant levels of inflammatory factors,resulting in retinal ganglion cell injury,cell death,and impaired neuroregeneration.This review focuses on examining the dual functions of microglia in glaucoma,evaluating their influence on retinal neurodegeneration and repair,and suggesting that modulating microglial activity could serve as a promising therapeutic strategy.Understanding the mechanisms of microglial action in glaucoma is crucial for unveiling the complex pathophysiological processes of the disease and developing new therapeutic strategies.展开更多
AIM:To identify early biomarkers associated with glaucomatous visual field(VF)progression in patients with normal-tension glaucoma(NTG).METHODS:This study included patients were divided into two groups based on diseas...AIM:To identify early biomarkers associated with glaucomatous visual field(VF)progression in patients with normal-tension glaucoma(NTG).METHODS:This study included patients were divided into two groups based on disease progression status.Tear samples were collected for proteomic analysis.Dataindependent acquisition(DIA)mass spectrometry combined with bioinformatic analyses was performed to identify and validate potential protein biomarkers for NTG progression.Additionally,differentially expressed proteins(DEPs)were evaluated using mediating effect models and receiver operating characteristic(ROC)curve analysis.RESULTS:A total of 19 patients(20 eyes)with NTG participated in this study,including 10 patients(4 males and 6 females;10 eyes)in the progression group with mean age of 67.70±9.03y and 10 patients(4 males and 6 females;10 eyes)in the non-progression group with mean age of 68.60±7.58y.A total of 158 significantly differentially expressed proteins were detected.UniProt database annotation identified 3 upregulated proteins and 12 downregulated proteins.Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis showed that these DEPs were mainly enriched in pathways such as oocyte meiosis.Gene Ontology(GO)enrichment analysis revealed functional clusters related to cellular processes.Weighted gene coexpression network analysis(WGCNA)indicated that the core proteins were primarily involved in the neurodegenerationmultiple diseases pathway and cellular processes.Mediating effect analysis identified PRDX4(L)as a potential protein biomarker.ROC curve analysis showed that GNAI1 had the largest area under the curve(AUC=0.889).CONCLUSION:This study identifies 15 differentially expressed proteins in the tear fluid of NTG patients,including PRDX4(L).PRDX4(L)plays a key role in oxidative stress.展开更多
基金supported by the National Natural Science Foundation of China,Nos.32271043(to ZW)and 82171047(to YM)the both Science and Technology Major Project of Shanghai,No.2018SHZDZX01 and ZJLabShanghai Center for Brain Science and Brain-Inspired Technology(to ZW)。
文摘Downregulation of the inwardly rectifying potassium channel Kir4.1 is a key step for inducing retinal Müller cell activation and interaction with other glial cells,which is involved in retinal ganglion cell apoptosis in glaucoma.Modulation of Kir4.1 expression in Müller cells may therefore be a potential strategy for attenuating retinal ganglion cell damage in glaucoma.In this study,we identified seven predicted phosphorylation sites in Kir4.1 and constructed lentiviral expression systems expressing Kir4.1 mutated at each site to prevent phosphorylation.Following this,we treated Müller glial cells in vitro and in vivo with the m Glu R I agonist DHPG to induce Kir4.1 or Kir4.1 Tyr^(9)Asp overexpression.We found that both Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression inhibited activation of Müller glial cells.Subsequently,we established a rat model of chronic ocular hypertension by injecting microbeads into the anterior chamber and overexpressed Kir4.1 or Kir4.1 Tyr^(9)Asp in the eye,and observed similar results in Müller cells in vivo as those seen in vitro.Both Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression inhibited Müller cell activation,regulated the balance of Bax/Bcl-2,and reduced the m RNA and protein levels of pro-inflammatory factors,including interleukin-1βand tumor necrosis factor-α.Furthermore,we investigated the regulatory effects of Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression on the release of pro-inflammatory factors in a co-culture system of Müller glial cells and microglia.In this co-culture system,we observed elevated adenosine triphosphate concentrations in activated Müller cells,increased levels of translocator protein(a marker of microglial activation),and elevated interleukin-1βm RNA and protein levels in microglia induced by activated Müller cells.These changes could be reversed by Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression in Müller cells.Kir4.1 overexpression,but not Kir4.1 Tyr^(9)Asp overexpression,reduced the number of proliferative and migratory microglia induced by activated Müller cells.Collectively,these results suggest that the tyrosine residue at position nine in Kir4.1 may serve as a functional modulation site in the retina in an experimental model of glaucoma.Kir4.1 and Kir4.1 Tyr^(9)Asp overexpression attenuated Müller cell activation,reduced ATP/P2X receptor–mediated interactions between glial cells,inhibited microglial activation,and decreased the synthesis and release of pro-inflammatory factors,consequently ameliorating retinal ganglion cell apoptosis in glaucoma.
基金supported by the National Natural Science Foundation of China,No.82271115(to MY).
文摘Synaptic plasticity is essential for maintaining neuronal function in the central nervous system and serves as a critical indicator of the effects of neurodegenerative disease.Glaucoma directly impairs retinal ganglion cells and their axons,leading to axonal transport dysfuntion,subsequently causing secondary damage to anterior or posterior ends of the visual system.Accordingly,recent evidence indicates that glaucoma is a degenerative disease of the central nervous system that causes damage throughout the visual pathway.However,the effects of glaucoma on synaptic plasticity in the primary visual cortex remain unclear.In this study,we established a mouse model of unilateral chronic ocular hypertension by injecting magnetic microbeads into the anterior chamber of one eye.We found that,after 4 weeks of chronic ocular hypertension,the neuronal somas were smaller in the superior colliculus and lateral geniculate body regions of the brain contralateral to the affected eye.This was accompanied by glial cell activation and increased expression of inflammatory factors.After 8 weeks of ocular hypertension,we observed a reduction in the number of excitatory and inhibitory synapses,dendritic spines,and activation of glial cells in the primary visual cortex contralateral to the affected eye.These findings suggest that glaucoma not only directly damages the retina but also induces alterations in synapses and dendritic spines in the primary visual cortex,providing new insights into the pathogenesis of glaucoma.
基金supported by St.Erik Eye Hospital philanthropic donations,Vetenskapsrådet 2022-00799(to PAW).
文摘Neurodegenerative diseases account for a large and increasing health and economic burden worldwide.With an increasingly aged population,this burden is set to increase.Optic neuropathies make up a large proportion of neurodegenerative diseases with glaucoma being highly prevalent.Glaucoma is characterized by the progressive dysfunction and loss of retinal ganglion cells and their axons which make up the optic nerve.It is the leading cause of irreversible vision loss and affects an estimated 80 million people.The mammalian central nervous system is non-regenerative and,once lost or injured,retinal ganglion cells cannot regenerate an axon into the optic nerve under basal conditions.Thus,strategies that provide neuroprotection to stressed,dysfunctional,or dying retinal ganglion cells are likely to be of high therapeutic and translational value.Advancing age,genetics,and elevated intraocular pressure are all major risk factors for glaucoma,however,all clinically available glaucoma treatments focus on intraocular pressure management and do not directly address the neurodegenerative component of glaucoma.
基金supported by a Ph.D.scholarship from the YLSY program of the Republic of Turkiye,Ministry of National Educationfunded by Fight for Sight UK,grant reference#5183/5184。
文摘Glaucoma is characterized by chronic progressive optic nerve damage and retinal ganglion cell death.Although extensive research has been conducted on neuroprotection for retinal ganglion cells,there is still no treatment for clinical use.Recent evidence shows that extracellular vesicles isolated from a variety of stem cells are efficacious in retinal ganglion cell neuroprotection.In this study,we tested the novel extracellular vesicle source of the retinal progenitor R-28 cell line in vitro and in vivo.We isolated and characterized extracellular vesicles from R-28 cells and tested their therapeutic efficacy in terms of retinal ganglion cell survival in vitro and in an in vivo glaucoma model,measuring retinal ganglion cell survival and preservation of their axons.Additionally,we tested extracellular vesicles for their neuroprotective capacity in retinal ganglion cells differentiated from human embryonic stem cells.Finally,we investigated miRNA changes in retinal ganglion cells with R-28 extracellular vesicle treatment,and predicted possible pathways that may be modulated.R-28 extracellular vesicles improved retinal ganglion cell survival but failed to preserve axons significantly.Moreover,the results also illustrated the neuroprotection of R-28 extracellular vesicles on human retinal ganglion cells.Finally,we also showed changes in hsa-miRNA-4443,hsa-miRNA-216a-5p,hsa-let-7e-5p,hsa-miRNA-374b-5p,hsa-miRNA-331-3p,and hsa-miRNA-421 expressions,which may have neuroprotective potential on retinal ganglion cell degeneration.This study will pave the way for miRNA and extracellular vesicle-based neuroprotective therapies for glaucoma.
基金supported by the National Natural Science Foundation of China(32471057,32271043,82301215,and 82171047)the Shanghai Municipal Science and Technology Major Project(2018SHZDZX01)ZJLab,the Shanghai Center for Brain Science and Brain-Inspired Technology.
文摘Interaction between Müller cells and microglia aggravates neuroinflammation,resulting in retinal ganglion cell(RGC)death in glaucoma.Here,we investigated how tumor necrosis factor-alpha(TNF-α)produced by activated microglia mediates the crosstalk between Müller cells and microglia and impacts RGC injury in a chronic ocular hypertension(COH)glaucoma model.In COH retinas,elevated TNF-αinduced the activation of Müller cells and microglia,and recruited microglia to the ganglion cell layer.Co-culture with Müller cells enhanced TNF-α-induced microglial activation,migration,and proliferation.Both in vivo and in vitro experiments confirmed that chemokine C-C motif ligand 2(CCL2),primarily released from Müller cells,mediated the TNF-α-induced effects on microglia in COH retinas.Knockdown of CCL2 attenuated RGC damage and vision loss.Our results demonstrate that TNF-αreleased from microglia induces the secretion of CCL2 from Müller cells,thus inducing microglial activation and migration,exacerbating retinal neuroinflammation and RGC injury in glaucoma.
基金supported by the Deutsche Forschungsgemeinschaft(DFG)with grants PR1569/1-1 and PR 1569/1-3(to VP).
文摘Globally,glaucoma stands as a primary cause of irreversible blindness,marked by intricate pathophysiological processes in which neuroinflammation plays a pivotal role.As the principal immune cells within the central nervous system,microglia play a dual function in the progression of glaucoma.Under standard physiological states,microglia safeguard the retina by offering neurotrophic support and removing cellular debris.In the pathological progression of glaucoma,microglia become activated and release significant levels of inflammatory factors,resulting in retinal ganglion cell injury,cell death,and impaired neuroregeneration.This review focuses on examining the dual functions of microglia in glaucoma,evaluating their influence on retinal neurodegeneration and repair,and suggesting that modulating microglial activity could serve as a promising therapeutic strategy.Understanding the mechanisms of microglial action in glaucoma is crucial for unveiling the complex pathophysiological processes of the disease and developing new therapeutic strategies.
基金Supported by The Eye Hospital of Wenzhou Medical University(No.KYQD20220304)The Fifth Batch of Provincial Ten Thousand Personnel Program Outstanding Talents Funding(No.474092204)+1 种基金Innovative Talents and Teams(2024)-The Fifth Batch of Funding Funds for Scientific and Technological Innovation Leading Talents Under the Provincial Ten Thousand Personnel Program(No.4240924003G)The Key R&D Program of Zhejiang(No.2022C03112).
文摘AIM:To identify early biomarkers associated with glaucomatous visual field(VF)progression in patients with normal-tension glaucoma(NTG).METHODS:This study included patients were divided into two groups based on disease progression status.Tear samples were collected for proteomic analysis.Dataindependent acquisition(DIA)mass spectrometry combined with bioinformatic analyses was performed to identify and validate potential protein biomarkers for NTG progression.Additionally,differentially expressed proteins(DEPs)were evaluated using mediating effect models and receiver operating characteristic(ROC)curve analysis.RESULTS:A total of 19 patients(20 eyes)with NTG participated in this study,including 10 patients(4 males and 6 females;10 eyes)in the progression group with mean age of 67.70±9.03y and 10 patients(4 males and 6 females;10 eyes)in the non-progression group with mean age of 68.60±7.58y.A total of 158 significantly differentially expressed proteins were detected.UniProt database annotation identified 3 upregulated proteins and 12 downregulated proteins.Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis showed that these DEPs were mainly enriched in pathways such as oocyte meiosis.Gene Ontology(GO)enrichment analysis revealed functional clusters related to cellular processes.Weighted gene coexpression network analysis(WGCNA)indicated that the core proteins were primarily involved in the neurodegenerationmultiple diseases pathway and cellular processes.Mediating effect analysis identified PRDX4(L)as a potential protein biomarker.ROC curve analysis showed that GNAI1 had the largest area under the curve(AUC=0.889).CONCLUSION:This study identifies 15 differentially expressed proteins in the tear fluid of NTG patients,including PRDX4(L).PRDX4(L)plays a key role in oxidative stress.
