TLR4/TRIF/Caspase-8/Caspase-1 Pathway in Choroidal Endothelial Cells Promotes Choroidal Neovascularization.

PURPOSE: The purpose of this study was to investigate the role and mechanism of caspase-8 in the development of choroidal neovascularization induced by age-related macular degeneration, with the aim of identifying a potential therapeutic target for neovascular age-related macular degeneration. METHODS: Mouse models of laser photocoagulation-induced choroidal neovascularization and hypoxic human choroidal endothelial cells were utilized to examine the involvement of caspase-8 in choroidal neovascularization development. The toll-like receptor 4/TIR domain-containing adaptor molecule 1/caspase-8 pathway was explored in hypoxic human choroidal endothelial cells to elucidate its contribution to pathological angiogenesis. Various experimental techniques, including inhibition assays and immunoblotting analysis, were employed to assess the effects and mechanisms of caspase-8 activation. RESULTS: Inhibition of caspase-8 demonstrated attenuated choroidal neovascularization development in mice subjected to laser photocoagulation. Activation of the toll-like receptor 4/TIR domain-containing adaptor molecule 1/caspase-8 pathway was observed in hypoxic human choroidal endothelial cells. Upon activation by the toll-like receptor 4/TIR domain-containing adaptor molecule 1 axis, caspase-8 directly cleaved caspase-1, leading to the cleavage of interleukin-1ß and interleukin-18 by caspase-1. Consequently, activation of interleukin-1ß and interleukin-18 through the toll-like receptor 4/TIR domain-containing adaptor molecule 1/caspase-8/caspase-1 pathway promoted the proliferative, migratory, and tube-forming abilities of hypoxic human choroidal endothelial cells. CONCLUSION: The findings of this study indicate that caspase-8 plays a crucial role in promoting choroidal neovascularization by activating interleukin-1ß and interleukin-18 through the toll-like receptor 4/TIR domain-containing adaptor molecule 1/caspase-8/caspase-1 pathway in choroidal endothelial cells. Therefore, targeting caspase-8 may hold promise as a therapeutic approach for neovascular age-related macular degeneration.

A cuproptosis-related prognostic signature for guiding clinical diagnosis and treatment in uveal melanoma patients.

Background: Cuproptosis, one of the most recently discovered forms of cell death, is induced by the disruption of copper binding to the mitochondrial respiratory acylation components. However, the mechanism underlying cuproptosis in uveal melanoma (UM) has not yet been adequately studied. Methods: RNA and clinical data were obtained from The Cancer Genome Atlas (TCGA) database. Differentially expressed cuproptosis-related genes were identified by R software. A prognostic signature was constructed by applying LASSO regression and Cox regression models. The associations between the signature and the immune microenvironment, overall survival, and drug sensitivity were studied. In addition, qPCR and Western blotting were performed on UM cells and RPE cell lines to verify the expression levels of the genes encoding dihydrolipoamide dehydrogenase (DLD) and dihydrolipoamide S-succinyltransferase (DLST) in UM cases. Results: Using a cuproptosis-related prognostic signature, UM samples were classified into high- and low-risk groups. A significant difference in overall survival between the two risk groups was evident. Receiver operating characteristic curves demonstrated that the signature is a reliable predictor of prognosis. Immune cell infiltration, drug sensitivity, and immune checkpoint expression were analysed. Significant immune difference between the two high-risk groups was found, and the high expression of immune checkpoints in high-risk groups suggests significant immunotherapy potential. In addition, drug sensitivity analysis experiments suggest that erlotinib may be a potential treatment for high-risk patients. The results of in vitro experiments confirmed that DLD and DLST had higher expression levels in UM cell lines. Conclusions: The prognostic signature developed in this study is a reliable biomarker for predicting the prognosis of UM and may serve as a tool for personalised treatment of patients with UM.

The Effects of STRA6 Regulation of the Circadian Rhythm on Choroidal Neovascularization.

Purpose: This study aims to investigate the relationship among STRA6, circadian rhythm, and choroidal neovascularization (CNV) formation, as well as the regulatory mechanism of STRA6 in CNV under circadian rhythm disturbances. Methods: C57BL/6J male mice (aged 6 weeks) were randomly divided into control and jet lag groups (using a time shift method every 4 days to disrupt the molecular clock's capacity to synchronize with a stable rhythm). A laser-induced CNV model was established in both the control and the jet lag group after 2 weeks of jet lag. The size of CNV lesions and vascular leakage were detected by morphological and imaging examination on the seventh day post laser. STRA6 was screened by full transcriptome sequencing. Bioinformatics analysis was conducted to assess the variation and association of STRA6 in the GSE29801 dataset. The effects of STRA6 were evaluated both in vivo and in vitro. The pathway mechanism was further elucidated and confirmed through immunofluorescence of paraffin sections and Western blotting. Results: The disturbance of circadian rhythm promotes the formation of CNV. Patients with age-related macular degeneration (AMD) exhibited higher levels of STRA6 expression compared to the control group, and STRA6 was enriched in pathways related to angiogenesis. In addition, CLOCK and BMAL1, which are initiators that drive the circadian cycle, had regulatory effects on STRA6. Knocking down STRA6 reversed the promotion of CNV formation caused by circadian rhythm disturbance in vivo, and it also affected the proliferation, migration, and VEGF secretion of RPE cells without circadian rhythm in vitro, as well as impacting endothelial cells. Through activation of the JAK2/STAT3/VEGFA signaling pathway in unsynchronized RPE cells, STRA6 promotes CNV formation. Conclusions: This study suggests that STRA6 reduces CNV production by inhibiting JAK2/STAT3 phosphorylation after circadian rhythm disturbance. The results suggest that STRA6 may be a new direction for the treatment of AMD.

Integrating Multi-omics to Identify Age-Related Macular Degeneration Subtypes and Biomarkers.

Age-related macular degeneration (AMD) is one of the most common causes of irreversible vision loss in the elderly. Its pathogenesis is likely multifactorial, involving a complex interaction of metabolic and environmental factors, and remains poorly understood. Previous studies have shown that mitochondrial dysfunction and oxidative stress play a crucial role in the development of AMD. Oxidative damage to the retinal pigment epithelium (RPE) has been identified as one of the major mediators in the pathogenesis of age-related macular degeneration (AMD). Therefore, this article combines transcriptome sequencing (RNA-seq) and single-cell sequencing (scRNA-seq) data to explore the role of mitochondria-related genes (MRGs) in AMD. Firstly, differential expression analysis was performed on the raw RNA-seq data. The intersection of differentially expressed genes (DEGs) and MRGs was performed. This paper proposes a deep subspace nonnegative matrix factorization (DS-NMF) algorithm to perform a multi-layer nonlinear transformation on the intersection of gene expression profiles corresponding to AMD samples. The age of AMD patients is used as prior information at the network's top level to change the data distribution. The classification is based on reconstructed data with altered distribution. The types obtained significantly differ in scores of multiple immune-related pathways and immune cell infiltration abundance. Secondly, an optimal AMD diagnosis model was constructed using multiple machine learning algorithms for external and qRT-PCR verification. Finally, ten potential therapeutic drugs for AMD were identified based on cMAP analysis. The AMD subtypes identified in this article and the diagnostic model constructed can provide a reference for treating AMD and discovering new drug targets.

LL37/FPR2 regulates neutrophil mPTP promoting the development of neutrophil extracellular traps in diabetic retinopathy.

Diabetic retinopathy (DR) is characterized by chronic, low-grade inflammation. This state may be related to the heightened production of neutrophil extracellular traps (NETs) induced by high glucose (HG). Human cathelicidin antimicrobial peptide (LL37) is an endogenous ligand of G protein-coupled chemoattractant receptor formyl peptide receptor 2 (FPR2), expressed on neutrophils and facilitating the formation and stabilization of the structure of NETs. In this study, we detected neutrophils cultured under different conditions, the retinal tissue of diabetic mice, and fibrovascular epiretinal membranes (FVM) samples of patients with proliferative diabetic retinopathy (PDR) to explore the regulating effect of LL37/FPR2 on neutrophil in the development of NETs during the process of DR. Specifically, HG or NG with LL37 upregulates the expression of FPR2 in neutrophils, induces the opening of mitochondrial permeability transition pore (mPTP), promotes the increase of reactive oxygen species and mitochondrial ROS, and then leads to the rise of NET production, which is mainly manifested by the release of DNA reticular structure and the increased expression of NETs-related markers. The PI3K/AKT signaling pathway was activated in neutrophils, and the phosphorylation level was enhanced by FPR2 agonists in vitro. In vivo, increased expression of NETs markers was detected in the retina of diabetic mice and in FVM, vitreous fluid, and serum of PDR patients. Transgenic FPR2 deletion led to decreased NETs in the retina of diabetic mice. Furthermore, in vitro, inhibition of the LL37/FPR2/mPTP axis and PI3K/AKT signaling pathway decreased NET production induced by high glucose. These results suggested that FPR2 plays an essential role in regulating the production of NETs induced by HG, thus may be considered as one of the potential therapeutic targets.

Honokiol Attenuates Choroidal Neovascularization by Inhibiting the Hypoxia-Inducible Factor-α/Vascular Endothelial Growth Factor Axis via Nuclear Transcription Factor-Kappa B Activation.

PURPOSE: Honokiol is a lignan isolated from Magnolia officinalis and exhibits anti-angiogenic properties. This study was conducted to investigate the role of honokiol in choroidal neovascularization. METHODS: C57BL/6 mice were treated with honokiol at 10-20 mg/kg by daily intraperitoneal injection from day 1 to 6 after laser photocoagulation. ARPE-19 cells were cultured under hypoxic conditions with or without the presence of honokiol. After laser photocoagulation and honokiol treatment, hematoxylin and eosin staining, immunofluorescence and fundus fluorescein angiography were used to analyze the effect of honokiol on choroidal neovascularization formation. Quantitative real-time PCR, western blot, enzyme-linked immunosorbent assay, immunofluorescence, luciferase assay, and chromatin immunoprecipitation were performed to explore the mechanism of honokiol in the pathological process of choroidal neovascularization. Finally, the role of honokiol on the human choroidal vascular endothelial cells was detected by using 5-ethynyl-20-deoxyuridine assay, Transwell and Tube formation assays. RESULTS: The results of hematoxylin and eosin staining and immunofluorescence suggested that honokiol reduced the thickness, length, and area of choroidal neovascularization lesions in laser-induced choroidal neovascularization mouse model. Fundus fluorescein angiography showed that choroidal neovascularization leakage was reduced in honokiol group and the concentration of 20 mg/kg showed better effects. Mechanism studies have shown that honokiol exerted inhibitory effects on choroidal neovascularization by inactivating hypoxia-inducible factor-1α/vascular endothelial growth factor axis through the nuclear transcription factor-kappa B signaling pathway. The same results were obtained in ARPE-19 cells under hypoxic conditions. Furthermore, the conditional medium of retinal pigmented epithelial cells promoted the proliferation, migration, and tube formation of human choroidal vascular endothelial cells, while honokiol reversed these. CONCLUSION: We demonstrated that honokiol attenuated choroidal neovascularization formation by inactivating the hypoxia-inducible factor-1α/vascular endothelial growth factor axis through nuclear transcription factor-kappa B signaling pathway.

Comparison of risk factors for OBL in FS-LASIK and SMILE correction for myopia and myopia astigmatism.

BACKGROUND: To find out the incidence and risk factors of opaque bubble layer (OBL) in eyes with myopia and myopic astigmatism following femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE). METHODS: A total of 1076 eyes from 569 patients who had FS-LASIK or SMILE were included in the retrospective research. For each kind of surgery, eyes were separated into two groups: "OBL" groups and "no OBL" groups. In the FS-LASIK group, eyes that developed OBL were split into "hard OBL" and "soft OBL" groups. The incidence and size of OBL were analyzed after watching the surgical procedure videotaped during the operation and taking screenshots. Surgical parameters, including sphere, cylinder, keratometry, corneal thickness, flap thickness, cap thickness, lenticule thickness, and visual acuity, were compared. RESULTS: In the FS-LASIK surgery, the incidence of OBL was 63.2% (347 eyes). A thicker central corneal thickness (CCT) was the only independent risk factor affecting the OBL area (ß = 0.126, P = 0.019). One hundred and thirty of these eyes had hard OBL, and the flap thickness of these eyes was thinner than that of those with soft OBL (P = 0.027). In the SMILE group, 26.6% (140 eyes) developed OBL. A higher flat keratometry (K) and a thicker residual stromal thickness (RST) were risk factors affecting the OBL area (ß = 0.195, P = 0.024; ß = 0.281, P = 0.001). CONCLUSION: The incidence of OBL differs between the FS-LASIK surgery and the SMILE surgery. There are differences in the factors influencing OBL between the two surgeries.

p21CIP/WAF1 saRNA inhibits proliferative vitreoretinopathy in a rabbit model.

PURPOSE: Proliferative vitreoretinopathy (PVR) is a disease process resulting from proliferation of retinal pigment epithelial (RPE) cells in the vitreous and periretinal area, leading to periretinal membrane formation and traction and eventually to postoperative failure after vitreo-retinal surgery for primary rhegmatogenous retinal detachment (RRD). The present study was designed to test the therapeutic potential of a p21CIP/WAF1 (p21) inducing saRNA for PVR. METHODS: A chemically modified p21 saRNA (RAG1-40-53) was tested in cultured human RPE cells for p21 induction and for the inhibition of cell proliferation, migration and cell cycle progression. RAG1-40-53 was further conjugated to a cholesterol moiety and tested for pharmacokinetics and pharmacodynamics in rabbit eyes and for therapeutic effects after intravitreal administration in a rabbit PVR model established by injecting human RPE cells. RESULTS: RAG1-40-53 (0.3 mg, 1 mg) significantly induced p21 expression in RPE cells and inhibited cell proliferation, the progression of cell cycle at the G0/G1 phase and TGF-ß1 induced migration. After a single intravitreal injection into rabbit eyes, cholesterol-conjugated RAG1-40-53 exhibited sustained concentration in the vitreal humor beyond at least 8 days and prevented the progression of established PVR. CONCLUSION: p21 saRNA could represent a novel therapeutics for PVR by exerting a antiproliferation and antimigration effect on RPE cells.

Efficacy and effectiveness of anti-VEGF or steroids monotherapy versus combination treatment for macular edema secondary to retinal vein occlusion: a systematic review and meta-analysis.

BACKGROUND: Retinal vein occlusion (RVO) is the main cause of retinal vascular blindness. Laser photocoagulation therapy is the regarded as the standard treatment for branch retinal vein occlusion (BRVO) in the guidelines, but it is not effective for macular edema (ME) secondary to central retinal vein occlusion (CRVO). As anti-VEGF (vascular endothelial growth factor) or steroids monotherapy has been used to treat RVO, but each has its advantages and disadvantages. Our purpose was to evaluate the efficacy and safety of intraocular injection of anti-VEGF combined with steroids versus anti-VEGF or steroids monotherapy for ME secondary to RVO. METHODS: We systematically searched trials on Pubmed, Embase, Cochrane Library, Web of Science and China National Knowledge Infrastructure (CNKI) for RCTs (random clinical trials) or non-RCTs, comparing anti-VEGF or steroids monotherapy to their combination. The primary outcomes were changes in best-corrected visual acuity (BCVA), central macular thickness (CMT) and intraocular pressure (IOP). The pooled data was analyzed by random effects model. FINDINGS: A total of 10 studies selected from 366 studies were included in this meta-analysis. Our results favored anti-VEGF with steroids combination therapy in comparison with anti-VEGF {pooled SMD (standardized mean difference), 95% CI, -0.16 [-0.28, -0.04], P = 0.01} or steroids (pooled SMD, 95% CI, -0.56 [-0.73, -0.40], P < 0.00001) alone on changes of BCVA. Compared with anti-VEGF monotherapy group, the combination therapy also had a better effect {pooled MD (mean difference), 95% CI, -9.62 [-17.31, -1.93], P = 0.01)} at improvements on CMT. On the changes of IOP, assessment favored that combination therapy was associated with a better relief of IOP compared to steroids monotherapy group (pooled MD, 95% CI, -5.93 [-7.87, -3.99],P < 0.00001). What's more, the incidence of ocular hypertension was lower in the combined treatment group compared with control group treated with steroids alone (Odds Ratio, 95% CI, 0.21 [0.06, 0.77], P = 0.02). Results also showed that the combination group can prolong the average time to first anti-VEGF reinjection (MD, 95% CI, 1.74 [0.57, 2.90], P = 0.003) compared to control group treated with anti-VEGF alone. CONCLUSION: Anti-VEGF with steroids combination treatment can enable a better achievement of improving BCVA, CMT, reducing the risk of increased IOP and improving patient prognosis compared to anti-VEGF or steroids therapy alone, lengthening the average time to anti-VEGF reinjection with reducing the injections during follow-up.

Regulator of G-protein signaling 1 promotes choroidal neovascularization in age-related macular degeneration.

Background: Age-related macular degeneration (AMD) is the leading cause of blindness, and is associated with oxidative stress and the development of new blood vessels. At present, the main clinical treatment for AMD includes intraocular injection of vascular endothelial growth factor (VEGF). However, treatment includes repeated injections with significant side-effects. Therefore, new treatment options are required. The aim of the present study was to discover the new treatment target of AMD from the gene level. Methods: The Gene Expression Omnibus (GEO) database was used to analyze the differential gene expression in AMD, and the regulator of G-protein signaling 1 (RGS1) was obtained by bioassay. Western blotting and quantitative reverse transcription polymerase chain reaction (qRT-PCR) were used to detect the expression levels of RGS1, VEGF, and other related molecules in human microvascular endothelial cells (HMECs) under different conditions. Cell viability, apoptosis, and proliferation of HMECs were measured by Cell Counting Kit-8 proliferation assay. Immunofluorescence and immunohistochemistry detected the interaction between RGS1, platelet endothelial cell adhesion molecule-1, and VEGF. Results: RGS1 was found to closely associated with the proliferation of vascular endothelial cells, and therefore, with angiogenesis. The expression of RGS1, VEGF, and platelet endothelial cell adhesion molecule-1 was upregulated in laser model mice and hypoxia model HMECs. Knockout of RGS1 inhibits the expression of VEGF and HMEC proliferation, thereby inhibiting AMD angiogenesis. Conclusions: Our results support the use of RGS1 as a new potential target for the future treatment of AMD.

Effectiveness of Panretinal Photocoagulation Plus Intravitreal Anti-VEGF Treatment Against PRP Alone for Diabetic Retinopathy: A Systematic Review With Meta-Analysis.

Objective: To compare the efficacy and safety of panretinal photocoagulation (PRP) combined with intravitreal anti-vascular endothelial growth factor (anti-VEGF) against PRP monotherapy for diabetic retinopathy (DR). Methods: We searched Pubmed, Cochrane Library, Web of Science, Embase, and Science Direct Register of Controlled Trials from April 2011 to January 2021 to identify the randomized trials that compared the efficacy and safety between PRP combined with intravitreal anti-VEGF and PRP monotherapy for DR. We searched in the following databases between April 2011 and January 2021: Pubmed, Cochrane Library, Web of Science, Embase, and Science Direct without any restriction of countries or article type. The outcome measures were the best-corrected visual acuity (BCVA), neovascularization on the disc (NVD), neovascularization elsewhere (NVE), central macula thickness (CMT), and total retinal volume over time (FAS), and we also observed the adverse events (AEs) between the two groups. Results: A total of 351 studies were identified, of which 11 studies were included in this meta-analysis (N = 1,182 eyes). Compared with PRP monotherapy, PRP plus anti-VEGF combination treatment produced a mean reduction in BCVA in units of logMAR of -0.23 [95% CI -0.32, -0.15] or a mean improvement in BCVA in units of letters of 4.99 [95% CI 3.79, 6.19], and also yielded a mean reduction in NVD of -28.41 [95% CI -30.30, -26.52], in NVE of -1.33 [95% CI -1.52, -1.14], in CMT of -1.33 [95% CI -1.52, -1.14], or in total FAS. No significant difference was observed on the risk of AEs as vitreous hemorrhage, elevation in intraocular pressure, and cataract between the two different treatments. Conclusion: PRP with anti-VEGF combination treatment can achieve the ideal efficacy on DR by improving BCVA and NV regression, with no potential increased incidence of AEs, which proves that the combination therapy is an efficient therapeutic strategy that could improve the management of patients with DR.

Association between cystatin C and diabetic retinopathy among type 2 diabetic patients in China: a Meta-analysis.

AIM: To explore the correlation between cystatin C (Cys-C) and diabetic retinopathy (DR) in those patients with type 2 diabetes mellitus (DM) in China. METHODS: Articles were collected from China National Knowledge Infrastructure (CNKI), Wanfang, VIP, PubMed, EMBASE, Cochrane Library, Clinical Trials.gov, and Google Scholar. Quality and risk of bias within included studies was assessed using the Newcastle-Ottawa scale (NOS). Heterogeneity was determined by using Cochran's Q-test and Higgins I 2 statistics. Mean differences (MDs) and 95% confidence intervals (CIs) of Cys-C within the diabetes without retinopathy (DWR) and DR, DWR and non-proliferative diabetic retinopathy (NPDR), NPDR and proliferative diabetic retinopathy (PDR) were collected by using random-effects model because of high heterogeneity. Meta-analysis was conducted based on 23 articles of 2331 DR including NPDR and PDR patients and 2023 DWR patients through Review Manager 5.3. Subgroup analyses were also performed according to DM duration, body mass index (BMI), total cholesterol (TC), total triglycerides (TG), low-density lipoprotein C (LDL-C), and high-density lipoprotein C (HDL-C), sample origins and methods. Publication bias was assessed by the funnel plot. RESULTS: Cys-C level in DR patients was increased compared with that of DWR (total MD: 0.69, 95%CI: 0.41 to 0.97, Z=4.79, P<0.01). Besides, the synthesized results of the studies showed the similar findings in the DWR vs NPDR group (total MD: 0.29, 95%CI 0.20 to 0.39, Z=6.02, P<0.01) and the NPDR vs PDR group (total MD: 0.63, 95%CI 0.43 to 0.82, Z=6.33, P<0.01). Heterogeneity of most of the subgroup analyses was still obvious (I 2≥50%, P<0.1). Forest plots of different subgroups indicated that there was a slight increase of Cys-C during the period between DWR and DR, DWR and NPDR, NPDR and PDR. Funnel plot showed that there was no significant publication bias. CONCLUSION: The elevated Cys-C is closely related with DR and probably plays a critical role in its progression.

TNF-α released from retinal Müller cells aggravates retinal pigment epithelium cell apoptosis by upregulating mitophagy during diabetic retinopathy.

Retinal pigment epithelium (RPE) cell damage, including mitophagy-associated cell apoptosis, accelerates the pathogenesis of diabetic retinopathy (DR), a common complication of diabetes that causes blindness. Müller cells interact with RPE cells via pro-inflammatory cytokines, such as tumor necrosis factor α (TNF-α). Herein, we investigated the role of the RPE cell epidermal growth factor receptor (EGFR)/p38 mitogen-activated protein kinase (p38)/nuclear factor kappa B (NF-κB) pathway in Müller cell-derived TNF-α-induced mitophagy-associated apoptosis during DR. Our results showed that TNF-α released from Müller cells activated the EGFR/p38/NF-κB/p62 pathway to increase mitophagy and apoptosis in RPE cells under high glucose (HG) conditions. Additionally, blockade of the TNF-α/EGFR axis alleviates blood-retina barrier breakdown in diabetic mice. Our data further illustrate the effects of the Müller cell inflammatory response on RPE cell survival, implying potential molecular targets for DR treatment.

Geniposide alleviates choroidal neovascularization by downregulating HB-EGF release from RPE cells by downregulating the miR-145-5p/NF-κB axis.

Age-related macular degeneration (AMD), mainly wet AMD, is the major reason for nonreversible vision loss worldwide. Choroidal neovascularization (CNV) is a characteristic pathological manifestation of wet AMD. Stress or injury to the retinal pigment epithelium (RPE) induces proangiogenic factors that drive CNV. An iridoid glycoside extracted from the fruit of gardenia, geniposide (GEN) plays an antiangiogenic role. In this study, GEN inhibited the transcription and expression of heparin-binding epidermal growth factor (HB-EGF), a proangiogenic factor, in hypoxic RPE cells and a mouse laser-induced CNV model. Inhibition of glucagon-like peptide-1 receptor (GLP-1R), a GEN receptor blocker, eliminated the protective effect of GEN. Additionally, GEN decreased the transcription and expression of HB-EGF in hypoxia-exposed RPE cells by downregulating the miR-145-5p/NF-κB axis. Therefore, our research provides a promising novel strategy for wet AMD therapy.

Association between retinopathy, nephropathy, and periodontitis in type 2 diabetic patients: a Meta-analysis.

AIM: To verify the association between retinopathy, nephropathy, and periodontitis in type 2 diabetic (T2D) patients. METHODS: Several electronic databases were available for our comprehensive search including China National Knowledge Infrastructure (CNKI), Chinese VIP Information (VIP), Wanfang, Web of Science, ScienceDirect and PubMed and were queried for relevant citations (updated to Mar. 2019). RevMan was utilized to perform Meta analysis and publication bias detection. After evaluation of the methodological quality of included studies, a fixed or random effect model was utilized to analyze data from included studies. RESULTS: A total of eight articles were finally included in this Meta analysis. In all 3987 subjects, there were 1207 T2D patients accompanying with microvascular complications and 1734 patients with periodontitis as well. The Meta forest plot presented little heterogeneity of the eight studies (P<0.00001, I 2=89%). The total effect demonstrated periodontitis was associated with overall microvascular complications (OR: 1.96, 95%CI: 1.67-2.30, Z=8.25, P<0.00001). Subgroup investigations among the studies in Asian (OR: 2.33, 95%CI: 1.91-2.85) and North American (OR: 1.42, 95%CI: 1.08-1.86) populations confirmed the existed association between retinopathy, nephropathy, and periodontitis. While the strength of such associations between periodontitis and diabetic microvascular complications were more obvious in the Asians than North Americans. All the results indicated that periodontitis was associated with diabetic retinopathy (OR: 3.77, 95%CI: 2.71-5.24), diabetic nephropathy (OR: 1.55, 95%CI: 1.24-1.94) in T2D patients. CONCLUSION: The periodontitis is associated with diabetic retinopathy, diabetic nephropathy among T2D patients and further large sample size clinical trials are in need to confirm the findings.

Fruquintinib inhibits VEGF/VEGFR2 axis of choroidal endothelial cells and M1-type macrophages to protect against mouse laser-induced choroidal neovascularization.

Wet age-related macular degeneration, which is characterized by choroidal neovascularization (CNV) and induces obvious vision loss. Vascular endothelial growth factor (VEGF) family member VEGF-A (also named as VEGF) and its receptor VEGFR2 contribute to the pathogenesis of CNV. Choroidal endothelial cells (CECs) secret C-C motif chemokine ligand 2 (CCL2), which attracts macrophages to CNV lesion and promotes macrophage M1 polarization. Accordingly, infiltrating macrophages secret inflammatory cytokines to promote CNV. In vivo, intravitreal injection of fruquintinib (HMPL-013), an antitumor neovascularization drug, alleviated mouse CNV formation without obvious ocular toxicity. Meanwhile, HMPL-013 inhibited VEGF/VEGFR2 binding in CECs and macrophages, as well as macrophage M1 polarization. In vitro, noncontact coculture of human choroidal vascular endothelial cells (HCVECs) and macrophages under hypoxia conditions was established. HMPL-013 downregulated VEGF/VEGFR2/phosphoinositide-3-kinase/protein kinase B (AKT)/nuclear factor kappa B pathway and CCL2 secretion in HCVECs, as well as VEGF/VEGFR2-induced macrophage M1 polarization under hypoxia condition. In addition, HMPL-013 inhibited HCEVC derived CCL2-induced macrophage migration and M1 polarization, along with macrophage M1 polarization-induced HCVECs proliferation, migration, and tube formation. Altogether, HMPL-013 alleviated CNV formation might via breaking detrimental cross talk between CECs and macrophages.

Andrographolide attenuates choroidal neovascularization by inhibiting the HIF-1α/VEGF signaling pathway.

Choroidal neovascularization (CNV), a characteristic of wet age-related macular degeneration (AMD), leads to severe vision loss amongst the elderly in the developed countries. Currently, the premier treatment for AMD is anti-VEGF therapy, which has limited efficacy, and is still controversial. Previous studies have showed that Andrographolide (Andro) had various biological effects, including anti-angiogenesis, anti-inflammation, and antioxidant. However, the effect of Andro on the formation of CNV has not been studied thus far. Here our results showed that Andro reduced the expression levels of HIF-1α and VEGF in the RF/6A cells chemical hypoxia model and the laser-induced CNV mouse model. Moreover, Andro inhibited the tube formation activity of RF/6A cells under hypoxic conditions. Furthermore, intraperitoneal injection of Andro reduced the severity of choroidal vascular leakage and the size of CNV in the laser-induced CNV mouse model, indicating that Andro attenuated the development of CNV by inhibiting the HIF-1α/VEGF signaling pathway. These results suggest that Andro could be a potential novel therapeutic agent for AMD.

Association between Retinal Vascular Geometric Changes and Cognitive Impairment: A Systematic Review and Meta-Analysis.

BACKGROUND AND PURPOSE: Previous studies have explored the association between retinal vascular changes and cognitive impairment. The retinal vasculature shares some characteristics with the cerebral vasculature, and quantitative changes in it could indicate cognitive impairment. Hence, a comprehensive meta-analysis was performed to clarify the potential relationship between retinal vascular geometric changes and cognitive impairment. METHODS: Relevant databases were scrupulously and systematically searched for retinal vascular geometric changes including caliber, tortuosity, and fractal dimension (FD), and for cognitive impairment. The Newcastle-Ottawa Scale was used to evaluate the methodological quality of included studies. RevMan was used to perform the meta-analysis and detect publication bias. Sensitivity analyses were also performed. RESULTS: Five studies that involved 2,343 subjects were finally included in the meta-analysis. The results showed that there was no significant association between central retinal artery equivalents (Z=1.17) or central retinal venular equivalents (Z=1.74) and cognitive impairment (both p>0.05). Similarly, no significant difference was detected in retinal arteriolar tortuosity (Z=0.91) and venular tortuosity (Z=1.31) (both p>0.05). However, the retinal arteriolar FD (mean difference: -0.03, 95% CI: -0.05, -0.01) and venular FD (mean difference: -0.03, 95% CI: -0.05, -0.02) were associated with cognitive impairment. CONCLUSIONS: A smaller retinal microvascular FD might be associated with cognitive impairment. Further large-sample and well-controlled original studies are required to confirm the present findings.

Brivanib, a multitargeted small-molecule tyrosine kinase inhibitor, suppresses laser-induced CNV in a mouse model of neovascular AMD.

In age-related macular degeneration (AMD), choroidal neovascularization (CNV), a major pathologic feature of neovascular AMD (nAMD), affects 10% of patients, potentially causing serious complications, including vision loss. Vascular endothelial growth factor receptor 2 (VEGFR2) and fibroblast growth factor receptor 1 (FGFR1) contribute to the pathogenesis of CNV. Brivanib is an oral selective dual receptor tyrosine kinase (RTK) inhibitor of FGFRs and VEGFRs, especially VEGFR2 and FGFR1. In this study, brivanib inhibited zebrafish embryonic angiogenesis without impairing neurodevelopment. In a mouse CNV model, brivanib intravitreal injection blocked phosphorylation of FGFR1 and VEGFR2 and reduced CNV leakage, area, and formation without causing intraocular toxicity. Moreover, brivanib oral gavage reduced CNV leakage and area. Accordingly, brivanib remained at high concentrations (above 14,000 ng/ml) in retinal/choroidal/scleral tissues following intravitreal injection. Similarly, brivanib remained at high concentrations (over 10,000 ng/ml) in retinal/choroidal/scleral tissues following oral gavage. Finally, in vitro cell experiments demonstrated that brivanib inhibited the proliferation, migration and tube formation of microvascular endothelial cells. In conclusion, our study suggested that brivanib treatment could be a novel therapeutic strategy for nAMD.

Computer aided diabetic retinopathy detection based on ophthalmic photography: a systematic review and Meta-analysis.

AIM: To ensure the diagnostic value of computer aided techniques in diabetic retinopathy (DR) detection based on ophthalmic photography (OP). METHODS: PubMed, EMBASE, Ei village, IEEE Xplore and Cochrane Library database were searched systematically for literatures about computer aided detection (CAD) in DR detection. The methodological quality of included studies was appraised by the Quality Assessment Tool for Diagnostic Accuracy Studies (QUADAS-2). Meta-DiSc was utilized and a random effects model was plotted to summarize data from those included studies. Summary receiver operating characteristic curves were selected to estimate the overall test performance. Subgroup analysis was used to identify the efficiency of CAD in detecting DR, exudates (EXs), microaneurysms (MAs) as well as hemorrhages (HMs), and neovascularizations (NVs). Publication bias was analyzed using STATA. RESULTS: Fourteen articles were finally included in this Meta-analysis after literature review. Pooled sensitivity and specificity were 90% (95%CI, 85%-94%) and 90% (95%CI, 80%-96%) respectively for CAD in DR detection. With regard to CAD in EXs detecting, pooled sensitivity, specificity were 89% (95%CI, 88%-90%) and 99% (95%CI, 99%-99%) respectively. In aspect of MAs and HMs detection, pooled sensitivity and specificity of CAD were 42% (95%CI, 41%-44%) and 93% (95%CI, 93%-93%) respectively. Besides, pooled sensitivity and specificity were 94% (95%CI, 89%-97%) and 87% (95%CI, 83%-90%) respectively for CAD in NVs detection. No potential publication bias was observed. CONCLUSION: CAD demonstrates overall high diagnostic accuracy for detecting DR and pathological lesions based on OP. Further prospective clinical trials are needed to prove such effect.