Ocular fundus neovascularization (OFN) is a leading cause of irreversible vision loss. Conventional antivascular endothelial growth factor (anti-VEGF) therapies indiscriminately suppress pathological and reparative angiogenesis and fail to correct the senescence- and inflammation-driven microenvironment that sustains disease progression. Senescent endothelial cells (ECs) form the structural scaffold of pathological vessels, while neighboring senescent microglia exacerbate inflammatory signaling, together deteriorating the reactive oxygen species (ROS)-rich vascular-immune microenvironment. Here, we develop an injectable ROS-responsive senolytic hydrogel (PCC1/PHCF-Gel) that enables lesion-activated, sustained intraocular release of procyanidin C1 (PCC1), overcoming rapid clearance, oxidative degradation, and poor lesion retention associated with free PCC1. In oxygen-induced retinopathy and choroidal neovascularization models, PCC1/PHCF-Gel markedly reduces retinal senescence, suppresses pathological neovascularization, and restores neuroretinal function, outperforming symptom-directed therapies anti-VEGF therapy. Single-cell RNA sequencing reveals selective elimination of two pathogenic senescent cell subpopulations-CXCR4+ ECs and IFITM3+ microglia-thereby disrupting the reinforcing cycle of vascular and immune senescence and promoting reparative vascular regeneration. These findings establish a multifunctional, spatiotemporally controlled therapeutic paradigm and highlight PCC1/PHCF-Gel as a promising translational strategy for the precision treatment of OFN.

BACKGROUND:Endothelial cell (EC) senescence is a key contributor to retinal vascular dysfunction in diabetic retinopathy (DR), yet its molecular mechanisms remain incompletely understood. While PFKFB3 is well recognized for its critical function in modulating EC glycolysis and angiogenesis, its contribution to endothelial senescence in DR has not been elucidated. METHODS:Single-cell RNA sequencing was used to profile EC senescence signatures and barrier/tight-junction programs in diabetic retinas. PFKFB3/USP7 abundance and senescence in vivo and in vitro were assessed by Western blotting, SA-β-gal staining, immunofluorescence, and cell-cycle flow cytometry. PFKFB3-USP7 interaction was examined by co-immunoprecipitation, mass spectrometry, and nuclear colocalization. Retinal vascular dysfunction was quantified by Evans blue leakage and PAS-stained retinal trypsin digests. RESULTS:Single-cell analysis identified EC subclusters enriched for senescence transcripts and simultaneously depleted for barrier/tight-junction pathways in diabetic retinas. Hyperglycemia reduced PFKFB3 and impaired its nuclear entry, leading to prominent cellular senescence in vitro and in vivo, and restoration of PFKFB3 effectively reversed this phenotype. By establishing stable endothelial cell lines expressing PFKFB3 only in the nucleus (NLS mutant) or cytoplasm (K472Q mutant), we revealed that anti-senescent activity required PFKFB3 nuclear localization. Nuclear-localized PFKFB3 interacted with USP7, a critical modulator of the p53 pathway, and regulated the USP7-p53 axis by constraining their coupling, thereby promoting proteasomal degradation of p53. As a downstream effector of PFKFB3, USP7 abrogated the protective effect of PFKFB3, whereas its inhibition attenuated hyperglycemia-induced senescence and mitigated retinal vascular dysfunction. CONCLUSIONS:Our findings highlighted the essential role of nuclear PFKFB3 dysfunction and USP7-p53 axis dysregulation in mediating EC senescence under diabetic stress, suggesting that targeting PFKFB3 nuclear translocation may be a novel therapeutic strategy for the prevention of diabetic retinopathy.

PURPOSE:This study examines the protective effects of fenofibrate on retinal health in diabetic retinopathy, focusing on its ability to reduce inflammation, oxidative stress, and restore autophagy while preventing ferroptosis. METHODS:Using a streptozotocin (STZ)-induced diabetic rat model and cultured ARPE-19 cells under high glucose conditions, we assessed the impact of fenofibrate on oxidative stress markers, autophagy-related proteins, and tight junction integrity. Fenofibrate's role in modulating inflammation and preventing ferroptosis was also evaluated. RESULTS:Fenofibrate treatment reduced ROS production and NADPH oxidase activity, alleviating oxidative stress in retinal tissues. Additionally, fenofibrate enhanced autophagy, as indicated by increased LC3 expression, and maintained tight junction protein expression. These effects contributed to the stabilization of cellular homeostasis, potentially slowing disease progression. CONCLUSION:Fenofibrate offers significant protective effects in diabetic retinopathy by reducing inflammation and oxidative stress, promoting autophagy, and inhibiting ferroptosis, making it a promising therapeutic option for managing the disease.

OBJECTIVE:To investigate the regulatory role of IP3R2 on mitochondrial function in retinal pigment epithelial cells during the early stage of hypoxic stress preceding apoptosis. METHODS:ARPE-19 cell line was cultured in 1 % oxygen to establish an in vitro hypoxic model. The presence of hypoxia and absence of significant apoptosis in RPE cells were confirmed through hypoxia-inducible factor HIF-1α expression and apoptosis assays respectively. Mitochondrial function was evaluated using an ATP assay kit and flow cytometry. Immunoblotting was conducted to ascertain the expression levels of mitochondrial dynamics proteins (MFN2, DRP1, TOMM20) and mitochondrial calcium-related proteins (IP3R1, IP3R2, IP3R3, VDAC1). Mitochondrial morphology was observed using confocal microscopy. The impact of small interfering RNA (siRNA)-mediated IP3R2 knockdown on apoptosis and mitochondrial function was assessed in RPE cells. RESULTS:Under hypoxic stress before the onset of apoptosis in RPE cells, mitochondrial dysfunction and significant increase in mitochondrial calcium flux were observed, accompanied by a notable upregulation of IP3R2 expression under hypoxia. Knockdown of IP3R2 during the pre-apoptotic stage further impaired RPE function under hypoxia. CONCLUSION:IP3R2-mediated mitochondrial calcium overload is crucial for maintaining RPE function and mitochondrial homeostasis during the pre-apoptotic stage triggered by hypoxic stress.

Helicobacter pylori (H. pylori) is a key cause of chronic inflammation and gastric cancer, and Epstein-Barr virus (EBV) also contributes to gastric tumorigenesis. However, the role of EBV co-infection in H. pylori-related cancers remains unclear because of the lack of efficient ex vivo models. Organoids, which are derived from self-renewing stem cells, closely mimic in situ tissue structure and function, making them ideal for disease modeling. Here, we developed patient-derived normal gastric organoids (NGOs) and used high-accuracy microinjection to introduce EBV and H. pylori (NCTC11637 strain). We found that the co-infection of H. pylori and EBV induced a significant structural change and upregulated the expression of TFF1, VIL1, and Lgr5 to promote cell proliferation and tissue morphogenesis. Analysis of transmission electron microscopy revealed an increase of H. pylori internal location in NGOs after co-infection. Moreover, all tested H. pylori strains isolated from patients displayed similar toxicities when co-infected with EBV. These findings provide a fundamental basis for evaluating pathogen toxicity, predicting disease progression, and advancing the clinical treatment of gastric cancer. IMPORTANCE:Helicobacter pylori (H. pylori) infection is a major contributor to chronic inflammation and the development of gastric cancer. Furthermore, Epstein-Barr virus (EBV) has been shown to play a role in the oncogenic process of gastric cancer by promoting chronic inflammation and increasing tissue damage. However, the mechanism by which co-infection contributes to gastric carcinogenesis remains unclear. In this study, we used patient-derived gastric organoids as a model to establish EBV-H. pylori co-infection using microinjection technology and found that co-infection causes significant structural changes and promotes cell proliferation. This model will not only contribute to a better understanding of the pathogenesis of gastric cancer but will also be important for drug efficacy evaluation and the development of new therapeutic approaches.

OBJECTIVES:To assess the efficacy of antimicrobial blue light (aBL) in managing Candida albicans keratitis in rabbit corneas ex vivo and safety to retinal cells in vitro. METHODS:C. albicans (strain CEC-749) suspensions were exposed to aBL with different light irradiance to assess the susceptibility of C. albicans to aBL. An ex vivo C. albicans keratitis model using rabbit corneas infected with a bioluminescent strain CEC-749 was developed. aBL was delivered topically to the infected corneas after fungal inoculation at varying irradiances. Bioluminescent imaging was used to track corneal infection progression in real-time. To evaluate the toxicity of aBL to the retinal cells, photoreceptors (661W) and retinal pigment epithelium cells (ARPE-19) were exposed to aBL in vitro, with cell viability and apoptosis assessed. The viability change of 661W cells under intermittent irradiation of aBL is determined. RESULTS:At varying irradiances of 25, 50, and 100 mW/cm2 and a constant 405 nm blue light exposure of 216 J/cm2, 3.39-, 3.67-, and 2.83-log10 CFU of C. albicans were inactivated in suspensions, respectively. Bioluminescence imaging revealed that C. albicans keratitis was fully developed in ex vivo rabbit corneas 24 h following fungal inoculation. After exposure to 288 J/cm2 aBL, the fungal burden in the 6, 18, and 24 h-infected rabbit corneas was reduced by approximately 1.57-, 2.18-, and 1.47-log10, as determined by bioluminescence imaging. The viability and apoptosis of both 661W and ARPE-19 cells were significantly affected by continuous aBL delivery at 32.43 J/cm2. Intermittent irradiation with a total exposure of 37.50 J/cm2, administered as 12.50 J/cm2 per irradiation session with 2 h intervals for three sessions, did not affect the viability of 661W cells. CONCLUSIONS:aBL is a potential treatment for C. albicans keratitis. The intermittent irradiation approach using aBL to treat fungal keratitis could be a safety modality for clinical application.

Recent evidence indicates that FAM111B is significantly involved in the progression of various cancers. Nonetheless, the potential pan-cancer implications of FAM111B have not been systematically investigated. In this study, FAM111B’s expression and oncogenic potential were studied using TCGA and GTEx data via GEPIA2, TIMER2.0, and STRING tools. Pathway enrichment analyses with the GO, KEGG, Reactome, and WikiPathways databases were conducted to explore its role in cancer development. The results were validated via multiplex immunofluorescence assays of pancreatic cancer tissues, microarray assays of ovarian cancer tissues, and protein transcriptomics of ovarian cancer cells. The expression levels of FAM111B were elevated in most cancer types and were associated with poor prognostic outcomes. Mechanistically, FAM111B expression was positively correlated with the expression of genes involved in DNA homologous recombination repair and with the infiltration of Th2 CD4+ T cells. These observations were further substantiated in ovarian cancer cell lines and tissue specimens from pancreatic and ovarian cancers. FAM111B functions as a biomarker for the DNA repair pathway and Th2 CD4+ T-cell infiltration in human malignancies.

The telomere-associated protein TIN2 localizes to both telomeres and mitochondria. Nevertheless, the impact of TIN2 on retinal pigment epithelial (RPE) cells in diabetic retinopathy (DR) remains unclear. This research aims to examine the role of TIN2 in the senescence of RPE and its potential as a therapeutic target. Western blotting and immunofluorescence staining were utilized to identify TIN2 expression and mitophagy. RT-qPCR was employed to identify senescent associated secretory phenotype (SASP) in ARPE-19 cells infected with TIN2 overexpression. To examine mitochondria and the cellular senescence of RPE, TEM, SA-β-gal staining, and cell cycle analysis were used. The impact of TIN2 was examined using OCT and immunohistochemistry in mice. DHE staining and ZO-1 immunofluorescence were applied to detect RPE oxidative stress and tight junctions. Our research revealed that increased mitochondria-localized TIN2 aggravated the cellular senescence of RPE cells both in vivo and in vitro under hyperglycemia. TIN2 overexpression stimulated the mTOR signaling pathway in ARPE-19 cells and exacerbated the inhibition of mitophagy levels under high glucose, which can be remedied through the mTOR inhibitor, rapamycin. Knockdown of TIN2 significantly reduced senescence and mitochondrial oxidative stress in ARPE-19 cells under high glucose and restored retinal thickness and RPE cell tight junctions in DR mice. Our study indicates that increased mitochondria-localized TIN2 induced cellular senescence in RPE via compromised mitophagy and activated mTOR signaling. These results propose that targeting TIN2 could potentially serve as a therapeutic strategy in the treatment of DR.

Purpose:Diabetic retinopathy (DR) is one of the most common reasons for blindness. uncoupling protein 2 (UCP2), an uncoupling protein located in mitochondria, has been reported to be related to metabolic and vascular diseases. This research aimed to illustrate the function and mechanism of UCP2 in the pathogenesis of DR. Methods:Human epiretinal membranes were collected to investigate the expression of UCP2 by quantitative real-time polymerase chain reaction (qRT-PCR) and immunofluorescence. Primary human retinal microvascular endothelial cells (HRECs) were cultured in high glucose (HG) to establish an in vitro cell model for DR. Flow cytometry analysis was used to measure intracellular reactive oxygen species (ROS). Senescence levels were evaluated by the senescence-associated beta-galactosidase (SA-β-gal) assay, the expression of senescence marker P21, and cell-cycle analysis. Adenovirus-mediated UCP2 overexpression or knockdown and specific inhibitors were administered to investigate the underlying regulatory mechanism. Results:Proliferative fibrovascular membranes from patients with DR illustrated the downregulation of UCP2 and sirtuin 3 (SIRT3) by qRT-PCR and immunofluorescence. Persistent hyperglycemia-induced UCP2 downregulation in the progress of DR and adenovirus-mediated UCP2 overexpression protected endothelial cells from hyperglycemia-induced oxidative stress and senescence. Under hyperglycemic conditions, UCP2 overexpression attenuated NAD+ downregulation; hence, it promoted the expression and activity of SIRT3, an NAD+-dependent deacetylase regulating mitochondrial function. 3-TYP, a selective SIRT3 inhibitor, abolished the UCP2-mediated protective effect against oxidative stress and senescence. Conclusions:UCP2 overexpression relieved oxidative stress and senescence based on a novel mechanism whereby UCP2 can regulate the NAD+-SIRT3 axis. Targeting oxidative stress and senescence amelioration, UCP2-SIRT3 signaling may serve as a method for the prevention and treatment of DR and other diabetic vascular diseases.

Background Neovascular eye disease is characterized by pathological neovascularization, with clinical manifestations such as intraocular exudation, bleeding, and scar formation, ultimately leading to blindness in millions of individuals worldwide. Pathologic ocular angiogenesis often occurs in common fundus diseases including proliferative diabetic retinopathy (PDR), age-related macular degeneration (AMD), and retinopathy of prematurity (ROP). Anti-vascular endothelial growth factor (VEGF) targets the core pathology of ocular angiogenesis. Main body In recent years, therapies targeting metabolism to prevent angiogenesis have also rapidly developed, offering assistance to patients with a poor prognosis while receiving anti-VEGF therapy and reducing the side effects associated with long-term VEGF usage. Phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3), a key enzyme in targeted metabolism, has been shown to have great potential, with antiangiogenic effects and multiple protective effects in the treatment of neovascular eye disease. In this review, we summarize the mechanisms of common types of neovascular eye diseases; discuss the protective effect and potential mechanism of targeting PFKFB3, including the related inhibitors of PFKFB3; and look forward to the future exploration directions and therapeutic prospects of PFKFB3 in neovascular eye disease. Conclusion Neovascular eye disease, the most common and severely debilitating retinal disease, is largely incurable, necessitating the exploration of new treatment methods. PFKFB3 has been shown to possess various potential protective mechanisms in treating neovascular eye disease. With the development of several drugs targeting PFKFB3 and their gradual entry into clinical research, targeting PFKFB3-mediated glycolysis has emerged as a promising therapeutic approach for the future of neovascular eye disease.

Progressive dysfunction of the retinal pigment epithelium (RPE) and the adjacent photoreceptor cells in the outer retina plays a pivotal role in the pathogenesis of diabetic retinopathy (DR). Here, we observed a marked increase in oxidative stress-induced apoptosis in parallel with higher expression of telomeric protein TIN2 in RPE cells under hyperglycemia in vivo and in vitro. Delving deeper, we confirm that high glucose-induced elevation of mitochondria-localized TIN2 compromises mitochondrial activity and weakens the intrinsic antioxidant defense, thereby leading to the activation of mitochondria-dependent apoptotic pathways. Mechanistically, mitochondrial TIN2 promotes the phosphorylation of FOXO1 and its relocation to the mitochondria. Such translocation of transcription factor FOXO1 not only promotes its binding to the D-loop region of mitochondrial DNA-resulting in the inhibition of mitochondrial respiration-but also hampers its availability to nuclear target DNA, thereby undermining the intrinsic antioxidant defense. Moreover, TIN2 knockdown effectively mitigates oxidative-induced apoptosis in diabetic mouse RPE by preserving mitochondrial homeostasis, which concurrently prevents secondary photoreceptor damage. Our study proposes the potential of TIN2 as a promising molecular target for therapeutic interventions for diabetic retinopathy, which emphasizes the potential significance of telomeric proteins in the regulation of metabolism and mitochondrial function.Created with BioRender (https://www.biorender.com/).

This work aimed to assess the possible role of TRIM25 in regulating hyperglycemia-induced inflammation, senescence, and oxidative stress in retinal microvascular endothelial cells, all of which exert critical roles in the pathological process of diabetic retinopathy. The effects of TRIM25 were investigated using streptozotocin-induced diabetic mice, human primary retinal microvascular endothelial cells cultured in high glucose, and adenoviruses for TRIM25 knockdown and overexpression. TRIM25 expression was evaluated by western blot and immunofluorescence staining. Inflammatory cytokines were detected by western blot and quantitative real-time PCR. Cellular senescence level was assessed by detecting senescent marker p21 and senescence‐associated‐β‐galactosidase activity. The oxidative stress state was accessed by detecting reactive oxygen species and mitochondrial superoxide dismutase. TRIM25 expression is elevated in the endothelial cells of the retinal fibrovascular membrane from diabetic patients compared with that of the macular epiretinal membrane from non-diabetic patients. Moreover, we have also observed a significant increase in TRIM25 expression in diabetic mouse retina and retinal microvascular endothelial cells under hyperglycemia. TRIM25 knockdown suppressed hyperglycemia-induced inflammation, senescence, and oxidative stress in human primary retinal microvascular endothelial cells while TRIM25 overexpression further aggregates those injuries. Further investigation revealed that TRIM25 promoted the inflammatory responses mediated by the TNF-α/NF-κB pathway and TRIM25 knockdown improved cellular senescence by increasing SIRT3. However, TRIM25 knockdown alleviated the oxidative stress independent of both SIRT3 and mitochondrial biogenesis. Our study proposed TRIM25 as a potential therapeutic target for the protection of microvascular function during the progression of diabetic retinopathy.

Epstein-Barr virus (EBV), an oncogenic herpesvirus, is predominantly found in the latent infection form and is highly associated with many human malignancies, which mainly have poor prognoses and no effective treatments. Here, we obtained thirteen compounds from small-molecule libraries for specific inhibition of EBV-latently infected cell growth in vitro by high-throughput screening. Among them, cetrimonium bromide (CetB) was identified to selectively inhibit the growth of different EBV-infected B lymphoma cell lines. Importantly, CetB reduced EBNA1 protein stability, activated G1 arrest and early apoptosis of EBV-latently infected cells without viral lytic reactivation, which leads to dramatically inhibit colony formation and tumor growth of EBV-infected cells in vitro and in vivo, , and significantly prolong the survival of tumor-bearing mice. Overall, these findings demonstrate that CetB acts as a highly selective inhibitor of the growth of EBV-infected cells and has the potential for further development of effective therapeutic strategies specific against EBV-associated cancers.

Introduction: Since intrinsic ocular barrier limits the intraocular penetration of therapeutic protein through eye drops, repeated intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) agents are the standard therapy for neovascular agerelated macular degeneration (nAMD), which are highly invasive and may cause particular ocular complications, leading to poor patient compliance. Methods: Using Penetratin (Pen) as the ocular penetration enhancer and hyaluronic acid (HA) as the retina-targeting ligand, a dualmodified ophthalmic liposome (Penetratin hyaluronic acid-liposome/Conbercept, PenHA-Lip/Conb) eye drop was designed to noninvasively penetrate the ocular barrier and deliver anti-VEGF therapeutic agents to the targeted intraocular tissue. Results: PenHA-Lip effectively penetrates the ocular barrier and targets the retinal pigment epithelium via corneal and non-corneal pathways. After a single topical administration of conbercept-loaded PenHA-Lip (PenHA-Lip/Conb), the intraocular concentration of conbercept peaked at 18.74 +/- 1.09 ng/mL at 4 h, which is 11.55-fold higher than unmodified conbercept. In a laser-induced choroidal neovascularization (CNV) mouse model, PenHA-Lip/Conb eye drops three times daily for seven days inhibited CNV formation and progression without any significant tissue toxicity and achieved an equivalent effect to a single intravitreal conbercept injection. Conclusion: PenHA-Lip efficiently and safely delivered conbercept to the posterior eye segment and may be a promising noninvasive therapeutic option for nAMD.

The metabolic reprogramming of aerobic glycolysis contributes to tumorigenesis. High plasma lactate is a critical regulator in the development of many human malignancies; however, the underlying molecular mechanisms of cancer progression in response to lactate (LA) remain elusive. Here, we show that the reduction of Yin-Yang 1 (YY1) expression correlated with high LA commonly occurs in various cancer cell types, including B-lymphoma and cervical cancer. Mechanistically, LA induces YY1 nuclear export and degradation via HSP70-mediated autophagy adjacent to mitochondria in a histidine (His)-rich LA-responsive (LAR) motif-dependent manner. The mutation of the LAR motif blocks LA-mediated YY1 cytoplasmic accumulation and in turn enhances cell apoptosis. Furthermore, low expression of YY1 promotes colony formation, invasion, angiogenesis, and growth of cancer cells in response to LA in vitro and in vivo using a murine xenograft model. Taken together, our findings reveal a key LAR element and may serve as therapeutic target for intervening cancer progression. Implications: We have shown that lactate can induce YY1 degradation via its His-rich LAR motif and low expression of YY1 promotes cancer cell progression in response to lactate, leading to better prediction of YY1 targeting therapy.

Mitochondria-associated ER membranes (MAMs) are contact sites that enable bidirectional communication between the ER (endoplasmic reticulum) and mitochondria, including the transfer of Ca2+ signals. MAMs are essential for mitochondrial function and cellular energy metabolism. However, unrestrained Ca2+ transfer to the mitochondria can lead to mitochondria-dependent apoptosis. IP3R2 (Inositol 1,4,5-trisphosphate receptor 2) is an important intracellular Ca2+ channel. This study investigated the contribution of IP3R2-MAMs to hypoxia-induced apoptosis in photoreceptor cells. A photoreceptor hypoxia model was established by subretinal injection of hyaluronic acid (1%) in C57BL/6 mice and 1% O2 treatment in 661W cells. Transmission electron microscopy (TEM), ER-mitochondria colocalization, and the MAM reporter were utilized to evaluate MAM alterations. Cell apoptosis and mitochondrial homeostasis were evaluated using immunofluorescence (IF), flow cytometry, western blotting (WB), and ATP assays. SiRNA transfection was employed to silence IP3R2 in 661W cells. Upon hypoxia induction, MAMs were significantly increased in photoreceptors both in vivo and in vitro. This was accompanied by the activation of mitochondrial apoptosis and disruption of mitochondrial homeostasis. Elevated MAM-enriched IP3R2 protein levels induced by hypoxic injury led to mitochondrial calcium overload and subsequent photoreceptor apoptosis. Notably, IP3R2 knockdown not only improved mitochondrial morphology but also restored mitochondrial function in photoreceptors by limiting MAM formation and thereby attenuating mitochondrial calcium overload under hypoxia. Our results suggest that IP3R2-MAM-mediated mitochondrial calcium overload plays a critical role in mitochondrial dyshomeostasis, ultimately contributing to photoreceptor cell death. Targeting MAM constitutive proteins might provide an option for a therapeutic approach to mitigate photoreceptor death in retinal detachment.

Purpose:SYVN1, a gene involved in endoplasmic reticulum-associated degradation, has been found to exert a protective effect by inhibiting inflammation in retinopathy. This study aimed to clarify whether SYVN1 is involved in the pathogenesis of retinopathy of prematurity (ROP) and its potential as a candidate for target therapy.Methods:Human retinal microvascular endothelial cells (hRMECs) and a mouse model of oxygen-induced retinopathy (OIR) were used to reveal the retinopathy development-associated protein expression and molecular mechanism. An adenovirus overexpressing SYVN1 or vehicle control was injected intravitreally at postnatal day 12 (P12), and the neovascular lesions were evaluated in retinal flatmounts with immunofluorescence staining, and hematoxylin and eosin staining at P17. Visual function was assessed by using electroretinogram (ERG).Results:Endogenous SYVN1 expression dramatically decreased in hRMECs under hypoxia and in ROP mouse retinas. SYVN1 regulated the signal transducer and activator of transcription 3 (STAT3)/vascular endothelial growth factor (VEGF) axis. SYVN1 overexpression promoted ubiquitination and degradation of STAT3, decreased the levels of phospho-STAT3, secretion of VEGF, and formation of neovascularization in hRMECs, which could be rescued by STAT3 activator treatment. In addition, SYVN1 overexpression prevented neovascularization and extended physiologic retinal vascular development in the retinal tissues of OIR mice without affecting retinal function.Conclusions:SYVN1 has a protective effect against OIR, and the molecular mechanisms are partly through SYVN1-mediated ubiquitination of STAT3 and the subsequent downregulation of VEGF. These findings strongly support our assumption that SYVN1 confers ROP resistance and may be a potentially novel pharmaceutical target against proliferative retinopathy.

The accumulation of DNA damage induced by oxidative stress is a crucial pathogenic factor of endothelial loss in diabetic vascular complications, but it is still unknown whether aberrant glucose metabolism leads to defective DNA repair and accounts for hyperglycemia-induced endothelial oxidative stress injury. Here, we showed that Foxo1 knockdown alleviated diabetes-associated retinal DNA damage and vascular dysfunction. Mechanistically, FOXO1 knockdown avoided persistent DNA damage and cellular senescence under high glucose in endothelial cells by promoting DNA repair mediated by the MRN (MRE11-RAD50-NBS1 complex)-ATM pathway in response to oxidative stress injury. Moreover, FOXO1 knockdown mediated robust DNA repair by restoring glycolysis capacity under high glucose. During this process, the key glycolytic enzyme PFKFB3 was stimulated and, in addition to its promoting effect on glycolysis, directly participated in DNA repair. Under genotoxic stress, PFKFB3 relocated into oxidative stress-induced DNA damage sites and promoted DNA repair by interaction with the MRN-ATM pathway. Our study proposed that defective glycolysis-dependent DNA repair is present in diabetic endothelial cells and contributes to hyperglycemia-induced vascular dysfunction, which could provide novel therapeutic targets for diabetic vascular complications.

This study aims to investigate whether tert-butylhydroquinone protects the retina from oxidative stress in STZ-induced experimental diabetic rats through the activation of phosphinositide 3-kinase (PI3K)/Akt/endothelial nitric oxide synthase (eNOS) pathway.In vitro, NO, reactive oxygen species(ROS), eNOS, p-eNOS Ser1179, Akt, p-Akt Ser473 and L-NAME protein expression was analyzed within rMC-1 cells cultivated within normal control(NC), high glucose (HG) and HG-containing tert-butyl hydroquinone (tBHQ) (5 μM) medium. We confirmed tBHQ's protection through administering inhibitors of PI3K and Akt. In vivo, tBHQ was administered at a ratio of 1% (w/w) to diabetic rats was induced through an STZ injection (65 mg/kg) for a 3-month period, and the retinal expression of eNOS, p-eNOS Ser1179, Akt, and p-Akt Ser473 proteins was measured using Western blotting (WB) assay. We also utilized the TUNEL kit for detecting retinal cell apoptosis. The changes of retinal morphology and visual function were measured by performing hematoxylin-eosin staining (HE staining) and electroretinograms. In vitro, ROS levels were increased in the high glucose group, NO levels were decreased, and the relative expression of Akt/p-Akt Ser473 and eNOs/p-eNOS Ser1179 was reduced. tBHQ abolished these changes, and these effects were suppressed by specific inhibitors. In vivo, tBHQ upregulated retinal protein expression in STZ-induced diabetic rats, reduced retinal apoptotic cell numbers, and partially prevented abnormalities in retinal function and structure caused by diabetes. tBHQ alleviates oxidative stress during diabetic retinopathy by upregulating the PI3K/Akt/eNOS pathway and partially restoring the structure and function of the retina. It may play a role in delaying vision loss caused by diabetic retinopathy.