The mitochondrial unfolded protein response(UPRmt)represents a crucial intracellular stress response mechanism that plays a fundamental role in maintaining mitochondrial and cellular homeostasis. Growing evidence suggests that dysregulation of UPRmt contributes significantly to the pathogenesis of various systemic disorders, including neurodegenerative diseases such as Parkinson's and Alzheimer's diseases, as well as age-related pathologies. Emerging research has particularly highlighted the involvement of UPRmt in ocular diseases, including cataracts, glaucoma, and diabetic retinopathy. This comprehensive review examines the physiological functions of UPRmt and its regulatory mechanisms in age-related eye diseases. The roles of key UPRmt downstream effector molecules in ocular cell populations such as lens epithelial cells, retinal pigment epithelial cells, and retinal ganglion cells are systematically analyzed. Importantly, the dual regulatory nature of UPRmt in ocular pathophysiology is discussed, that is, its moderate activation promotes mitochondrial homeostasis, mitigates oxidative stress, and suppresses inflammatory responses, its chronic or excessive activation triggers apoptotic pathways, induces metabolic dysfunction, and ultimately accelerates disease progression. By elucidating these mechanisms, our review provides novel insights into ocular disease pathogenesis and proposes potential therapeutic strategies targeting UPRmt modulation for the prevention and treatment of age-related eye disorders.

Extracellular vesicles(EVs)are small vesicles secreted by cells,widely present in various body fluids,and they play important biological roles.In recent years,EVs have garnered significant attention as novel diagnostic and thera-peutic tools in multiple ocular diseases.Glaucoma,as a common cause of irreversible blindness,is primarily caused by optic nerve damage associated with pathologically elevated intraocular pressure.Emerging evidence indicates that EVs hold considerable therapeutic potential in glaucoma management,particularly in modulating aqueous humor circulation and pro-viding retinal neuroprotection.This review summarizes the latest research progress on EVs in the treatment of glaucoma.

Objective To investigate the effects of DNA Cross-Link Repair 1A(DCLRE1A)on mitochondrial func-tion in lens epithelial cells(LECs).Methods Thirty eyes from 30 patients with age-related cataracts(ARC)were select-ed and divided into three groups:cortical type(ARCC group),nuclear type(ARNC group),and posterior subcapsular type(ARPC group),with 10 cases in each group.Additionally,10 eyes from 10 age-matched patients diagnosed with epiretinal membrane and having clear lenses were selected as the control group.Western blot was used to detect the ex-pression levels of DCLRE1A protein in the anterior capsule tissues of patients in each group and in the lens epithelial cell line(SRA01/04)treated with hydrogen peroxide(H2O2)in vitro and overexpressed DCLRE1A model(OE-DCLRE1A group).The effects of overexpressed DCLRE1A on the expression levels of mitochondrial transcription factor(TFAM)and peroxisome proliferator-activated receptor-γ coactivator-1α(PGC1α)proteins were also detected.Normal cultured SRA01/04 cells were randomly divided into Control group(untreated),H2 O2 group,H2 O2+HA group(transfected with control plasmid HA),and H2O2+OE-DCLRE1A group(transfected with DCLRE1A plasmid).RT-PCR was used to measure mtD-NA expression in each group cells.Changes in mitochondrial membrane potential(MMP)and mitochondrial reactive oxy-gen species(ROS)in each group were detected by immunofluorescence staining.Results Western blot analysis showed that compared with the control group cells,the relative expression levels of DCLRE1A protein in the anterior capsule tis-sues of patients in the ARCC,ARNC,and ARPC groups were all decreased,with statistically significant differences(all P＜0.001).In the in vitro H2O2-induced oxidative damage model,compared with the Control group,the relative expression level of DCLRE1A protein in the H2O2 group was significantly decreased(P＜0.001).The overexpression efficiency results of DCLRE1A showed that,compared with the Control group,the relative expression level of DCLRE1A protein in the OE-DCLRE1A group cells was significantly increased,with statistical significance(P＜0.001).RT-PCR results showed that compared with the H2O2+HA group,the expression level of mtDNA in the H2O2+OE-DCLRE1A group was significantly in-creased(P＜0.001).Western blot analysis showed that compared with the H2O2+HA group,the relative expression levels of TFAM and PGC1α proteins in the H2O2+OE-DCLRE1A group were significantly increased(P＜0.001).Immunofluores-cence staining results showed that compared with the H2O2+HA group,the MMP level in the H2O2+OE-DCLRE1A group was significantly restored,and the accumulation of mitochondrial ROS was reduced(P＜0.001).Conclusion Under H2O2-induced oxidative stress conditions,DCLRE1A promotes the repair of damaged mtDNA in LECs by regulating mito-chondrial biogenesis,thereby reducing LEC apoptosis and participating in the occurrence and development of ARC.

Objective To investigate the effect of quercetin on paraptosis induced by low-concentration hydrogen peroxide(H2O2)in human lens epithelial cells(LECs).Methods The human lens epithelial cell line SRA01/04 was cul-tured in vitro and randomly divided into the following groups:control group,H2O2 group(50 μmol·L-1 H2O2),and H2O2+Quercetin group(50 μmol·L-1 H2O2 and 20 μmol·L-1 quercetin).The area and number of endoplasmic reticulum vacuoles in the cells were observed using transmission electron microscopy and super-resolution laser confocal microscopy.Intracellular reactive oxygen species(ROS)levels were detected using the DCFH-DA fluorescent probe.Western blot was performed to detect the expression levels of the following proteins:insulin-like growth factor 1 receptor(IGF1R),phos-phorylated IGF1R(p-IGF1R),ALG-2-interacting protein X(ALIX),glucose-regulated protein 78(GRP78),extracellular signal-regulated kinase(ERK),phosphorylated ERK(p-ERK),P38,and phosphorylated P38(p-P38).Additionally,len-ses from 8-week-old Sprague-Dawley rats were subjected to ex vivo culture and divided into the normal group,the H2O2 treatment group(50 μmol·L-1 H2O2),and the combination treatment group(50 μmol·L-1 H2O2 and 20 μmol·L-1 quer-cetin).The degree of lens opacity was observed under a stereomicroscope,and the area of lens opacity was quantified.The ultrastructure of the endoplasmic reticulum in the rat LECs was observed by transmission electron microscopy.Western blot was used to detect the expression levels of the aforementioned proteins in the rat LECs.Results Compared with the control group,the H2O2 group exhibited significant increases in the area and number of endoplasmic reticulum vacuoles,ROS levels,and the relative protein expression levels of p-IGF1R,p-ERK,p-P38,and GRP78,while the relative expression of ALIX protein was decreased(all P＜0.001).Compared with the H2 O2 group,the H2O2+quercetin group showed signifi-cant reductions in the area and number of endoplasmic reticulum vacuoles,ROS levels,and the relative expression levels of p-IGF1R,p-ERK,p-P38,and GRP78,while the relative expression of ALIX protein was increased(all P＜0.01).In the ex vivo cultured rat lens model,compared with the normal group,the H2O2 group displayed a significant increase in lens opac-ity area,expanded endoplasmic reticulum area in LECs,elevated relative expression levels of p-IGF1R,p-ERK,p-P38,and GRP78 proteins,and decreased ALIX expression(all P＜0.000 1).In contrast,the combination treatment group showed significantly reduced lens opacity area,decreased endoplasmic reticulum area in LECs,lower relative expression of p-IGF1R,p-ERK,p-P38,and GRP78,and increased ALIX expression compared to the H2O2 group(all P＜0.01).Conclu-sion Quercetin inhibits activation of the IGF1R/MAPK signaling pathway and alleviates endoplasmic reticulum stress,thereby effectively attenuating paraptosis in lens epithelial cells.These findings provide a novel strategy for the prevention and treatment of early age-related cataract.

Glaucoma,characterized by optic nerve damage and progressive damage to retinal ganglion cells(RGCs),is the leading cause of irreversible blindness.However,the specific mechanism of RGC damage has not been fully elucida-ted.In recent years,there is increasing evidence that microglia,especially disease-associated microglia(DAM),may play an important role in glaucomatous ganglion cell injury.In this paper,we reviewed the role and mechanism of DAM in RGC damage in glaucoma,aiming to provide new insights for further research on the mechanism of RGC damage and subsequent protection of RGCs.

Objective To investigate the effect of quercetin on paraptosis induced by low-concentration hydrogen peroxide(H2O2)in human lens epithelial cells(LECs).Methods The human lens epithelial cell line SRA01/04 was cul-tured in vitro and randomly divided into the following groups:control group,H2O2 group(50 μmol·L-1 H2O2),and H2O2+Quercetin group(50 μmol·L-1 H2O2 and 20 μmol·L-1 quercetin).The area and number of endoplasmic reticulum vacuoles in the cells were observed using transmission electron microscopy and super-resolution laser confocal microscopy.Intracellular reactive oxygen species(ROS)levels were detected using the DCFH-DA fluorescent probe.Western blot was performed to detect the expression levels of the following proteins:insulin-like growth factor 1 receptor(IGF1R),phos-phorylated IGF1R(p-IGF1R),ALG-2-interacting protein X(ALIX),glucose-regulated protein 78(GRP78),extracellular signal-regulated kinase(ERK),phosphorylated ERK(p-ERK),P38,and phosphorylated P38(p-P38).Additionally,len-ses from 8-week-old Sprague-Dawley rats were subjected to ex vivo culture and divided into the normal group,the H2O2 treatment group(50 μmol·L-1 H2O2),and the combination treatment group(50 μmol·L-1 H2O2 and 20 μmol·L-1 quer-cetin).The degree of lens opacity was observed under a stereomicroscope,and the area of lens opacity was quantified.The ultrastructure of the endoplasmic reticulum in the rat LECs was observed by transmission electron microscopy.Western blot was used to detect the expression levels of the aforementioned proteins in the rat LECs.Results Compared with the control group,the H2O2 group exhibited significant increases in the area and number of endoplasmic reticulum vacuoles,ROS levels,and the relative protein expression levels of p-IGF1R,p-ERK,p-P38,and GRP78,while the relative expression of ALIX protein was decreased(all P＜0.001).Compared with the H2 O2 group,the H2O2+quercetin group showed signifi-cant reductions in the area and number of endoplasmic reticulum vacuoles,ROS levels,and the relative expression levels of p-IGF1R,p-ERK,p-P38,and GRP78,while the relative expression of ALIX protein was increased(all P＜0.01).In the ex vivo cultured rat lens model,compared with the normal group,the H2O2 group displayed a significant increase in lens opac-ity area,expanded endoplasmic reticulum area in LECs,elevated relative expression levels of p-IGF1R,p-ERK,p-P38,and GRP78 proteins,and decreased ALIX expression(all P＜0.000 1).In contrast,the combination treatment group showed significantly reduced lens opacity area,decreased endoplasmic reticulum area in LECs,lower relative expression of p-IGF1R,p-ERK,p-P38,and GRP78,and increased ALIX expression compared to the H2O2 group(all P＜0.01).Conclu-sion Quercetin inhibits activation of the IGF1R/MAPK signaling pathway and alleviates endoplasmic reticulum stress,thereby effectively attenuating paraptosis in lens epithelial cells.These findings provide a novel strategy for the prevention and treatment of early age-related cataract.

Objective To investigate the impact of high mobility group box 1(HMGB1)on hydrogen peroxide(H2O2)-induced DNA damage and senescence in lens epithelial cells(LECs)under oxidative stress conditions.Methods Fluorescent quantitative real-time polymerase chain reaction(RT-PCR)technology was used to detect the mRNA expres-sion of HMGB1 in the anterior capsule tissue of patients with age-related cataract(ARC group)and epiretinal membrane(control group).Western blot analysis was employed to examine the changes in the protein expression of HMGB1 in the LEC line SRA01/04 after treatment with varying concentrations of H2O2(0,100,200,and 400 μmol·L-1).The optimal concentration was selected for subsequent establishment of a cellular oxidative damage model.The cultured SRA01/04 cells were divided into three groups:Control(untreated),HA(transfected with the control plasmid HA),and OE-HMGB1 groups(transfected with the HMGB1 plasmid).The mRNA and protein expression levels of HMGB1 were detected by RT-PCR and Western blot.The cultured SRA01/04 cells were divided into three groups:H2O2(treated with 400 μmol·L-1 H2O2),H2O2+HA(transfected with the control plasmid HA and simultaneously treated with 400 μmol·L-1 H2O2),and H2O2+OE-HMGB1 groups(transfected with the HMGB1 plasmid and simultaneously treated with 400 μmol·L-1 H2O2).Immunofluorescence was used to detect DNA oxidative damage in cells from each group.Western blot analysis was per-formed to assess the protein expression levels of phosphorylated histone H2A(γH2A),tumor protein p53(P53),cyclin-dependent kinase inhibitor 1A(P21),and cyclin-dependent kinase inhibitor 2A(P16)in cells from each group.Additional-ly,senescence-associated-β-galactosidase(SA-β-gal)staining was conducted to detect senescent changes in cells from each group.Results RT-PCR results indicated that the relative mRNA expression level of HMGB1 in the anterior capsule tissue of the ARC group was significantly decreased,compared with that in the control group(P＜0.001).Furthermore,in the H2O2-induced oxidative damage model,the relative protein expression level of HMGB1 decreased with the increase of the concentration of H2O2.Both RT-PCR and Western blot analyses revealed that the mRNA and protein expression levels of HMGB1 were both significantly elevated in the OE-HMGB1 group,compared with those in the HA group(both P＜0.001).The immunofluorescence staining results demonstrated that the protein expression of γH2A and the fluorescence intensity in the H2O2+OE-HMGB1 group were significantly decreases,compared with those in H2O2 and H2O2+HA groups(all P＜0.001).SA-β-gal staining results showed that the H2O2+OE-HMGB1 group had significantly less cells stained by SA-β-gal than H2O2 and H2O2+HA(both P＜0.001).Additionally,Western blot analysis revealed that,compared with those in H2O2 and H2O2+HA groups,the relative expression levels of senescence-associated proteins P53,P21,and P16 were significantly decreased in the H2O2+OE-HMGB1 group(all P＜0.01).Conclusion HMGB1 inhibits the accumula-tion of damaging DNA and senescence in LECs by enhancing DNA damage repair capabilities.

Objective To investigate the impact of high mobility group box 1(HMGB1)on hydrogen peroxide(H2O2)-induced DNA damage and senescence in lens epithelial cells(LECs)under oxidative stress conditions.Methods Fluorescent quantitative real-time polymerase chain reaction(RT-PCR)technology was used to detect the mRNA expres-sion of HMGB1 in the anterior capsule tissue of patients with age-related cataract(ARC group)and epiretinal membrane(control group).Western blot analysis was employed to examine the changes in the protein expression of HMGB1 in the LEC line SRA01/04 after treatment with varying concentrations of H2O2(0,100,200,and 400 μmol·L-1).The optimal concentration was selected for subsequent establishment of a cellular oxidative damage model.The cultured SRA01/04 cells were divided into three groups:Control(untreated),HA(transfected with the control plasmid HA),and OE-HMGB1 groups(transfected with the HMGB1 plasmid).The mRNA and protein expression levels of HMGB1 were detected by RT-PCR and Western blot.The cultured SRA01/04 cells were divided into three groups:H2O2(treated with 400 μmol·L-1 H2O2),H2O2+HA(transfected with the control plasmid HA and simultaneously treated with 400 μmol·L-1 H2O2),and H2O2+OE-HMGB1 groups(transfected with the HMGB1 plasmid and simultaneously treated with 400 μmol·L-1 H2O2).Immunofluorescence was used to detect DNA oxidative damage in cells from each group.Western blot analysis was per-formed to assess the protein expression levels of phosphorylated histone H2A(γH2A),tumor protein p53(P53),cyclin-dependent kinase inhibitor 1A(P21),and cyclin-dependent kinase inhibitor 2A(P16)in cells from each group.Additional-ly,senescence-associated-β-galactosidase(SA-β-gal)staining was conducted to detect senescent changes in cells from each group.Results RT-PCR results indicated that the relative mRNA expression level of HMGB1 in the anterior capsule tissue of the ARC group was significantly decreased,compared with that in the control group(P＜0.001).Furthermore,in the H2O2-induced oxidative damage model,the relative protein expression level of HMGB1 decreased with the increase of the concentration of H2O2.Both RT-PCR and Western blot analyses revealed that the mRNA and protein expression levels of HMGB1 were both significantly elevated in the OE-HMGB1 group,compared with those in the HA group(both P＜0.001).The immunofluorescence staining results demonstrated that the protein expression of γH2A and the fluorescence intensity in the H2O2+OE-HMGB1 group were significantly decreases,compared with those in H2O2 and H2O2+HA groups(all P＜0.001).SA-β-gal staining results showed that the H2O2+OE-HMGB1 group had significantly less cells stained by SA-β-gal than H2O2 and H2O2+HA(both P＜0.001).Additionally,Western blot analysis revealed that,compared with those in H2O2 and H2O2+HA groups,the relative expression levels of senescence-associated proteins P53,P21,and P16 were significantly decreased in the H2O2+OE-HMGB1 group(all P＜0.01).Conclusion HMGB1 inhibits the accumula-tion of damaging DNA and senescence in LECs by enhancing DNA damage repair capabilities.

Objective:To investigate the ocular pathogen spectrum and drug sensitivity characteristics of patients to be diagnosed with infectious keratitis within 10 years in two tertiary hospitals in Nantong City, Jiangsu Province, eastern China.Methods:A cross-sectional study was conducted.Microbial culture specimens from consecutive 1 404 patients with suspected infectious keratitis admitted to the Department of Ophthalmology at the First People's Hospital of Nantong City and Nantong University Affiliated Hospital from January 2014 to October 2023 were collected.The patients' general data, etiology and drug sensitivity test results were analyzed.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Nantong First People's Hospital (No.2021KT273) and Nantong University Affiliated Hospital (No.2019-K068).Results:Among 1 404 patients with suspected infectious keratitis, the positive rate of microbial culture was 37.04%(520/1 404).A total of 537 strains were isolated and cultured, with fungi accounting for 69.09%(371/537) and bacteria accounting for 30.91%(166/537).The common bacterial genera in fungal keratitis were Fusarium (47.17%, 175/371), Alternaria (15.90%, 59/371), Aspergillus (14.56%, 54/371), Certospora (10.78%, 40/371) and Penicillium (3.50%, 13/371).The annual composition ratio of Fusarium showed a downward trend, while Certospora showed an upward trend.The common bacteria in bacterial keratitis were Staphylococcus epidermidis (24.10%, 40/166), Streptococcus pneumoniae (17.47%, 29/166), Pseudomonas aeruginosa (13.25%, 22/166), Staphylococcus aureus (6.63%, 11/166) and Corynebacterium macginleyi (4.22%, 7/166).The annual composition ratio of Pseudomonas aeruginosa showed an increasing trend.The resistance rates of gram-positive bacteria to levofloxacin and vancomycin were 36.26% and 0% respectively, and the resistance rates of gram-negative bacteria to aminoglycosides and ceftazidime were <10%.A total of 61 bacterial strains (40.94%) were multi-drug resistant. Conclusions:Fusarium is common in fungal keratitis, and Corynebacterium macginleyi in bacterial keratitis may be a microbial feature in Nantong City.Levofloxacin may no longer be suitable as a first-line antibiotic for topical ocular use.

Glaucoma,characterized by optic nerve damage and progressive damage to retinal ganglion cells(RGCs),is the leading cause of irreversible blindness.However,the specific mechanism of RGC damage has not been fully elucida-ted.In recent years,there is increasing evidence that microglia,especially disease-associated microglia(DAM),may play an important role in glaucomatous ganglion cell injury.In this paper,we reviewed the role and mechanism of DAM in RGC damage in glaucoma,aiming to provide new insights for further research on the mechanism of RGC damage and subsequent protection of RGCs.