Recent evidence suggests that chloride channels are critical for cell proliferation, migration, and differentiation. We examined the effects of transforming growth factor (TGF)-β1 on chloride channel expression and associations with human conjunctival fibroblast (HConF) biology. To investigate the potential role of chloride channel (CLC)-2 in migration, transition to myofibroblasts and extracellular matrix (ECM) synthesis of HconF, a small interfering RNA (siRNA) approach was applied. TGF-β1-induced migration and transition of fibroblasts to myofibroblasts characterized by α-smooth muscle actin (α-SMA) expression, supported by increased endogenous expression of CLC-2 protein and mRNA transcripts. ECM (collagen I and fibronectin) synthesis in HConF was enhanced by TGF-β1. CLC-2 siRNA treatment reduced TGF-β1-induced cell migration, transition of fibroblasts to myofibroblasts, and ECM synthesis of HConF. CLC-2 siRNA treatment in the presence of TGF-β1 inhibited phosphorylation of PI3K and Akt in HConF. These findings demonstrate that CLC-2 chloride channels are important for TGF-β1-induced migration, differentiation, and ECM synthesis via PI3K/Akt signaling in HConF.

Background: The role of glaucoma in predicting Alzheimer’s disease (AD) factors is unknown. This current meta-analysis was aimed at evaluating the risk of AD events in individuals suffering from glaucoma based on a meta-analysis. Materials and methods: Databases which included Cochrane Library, PubMed, and EMBASE were searched to detect the relevant articles, with language being restricted to English. The risk of AD events in patients with glaucoma was analyzed using the combined hazard ratios. Results: This study included 8 articles with 131,987 subjects published after 2012. We identified glaucoma as the risk factor for disease-free survival (hazard ratio = 1.29; 95% confidence interval = 1.05–1.59; P = .000; I² = 95.1%) in AD patients. According to subgroup analyses, normal tension glaucoma group was the major risk factor for disease-free survival of AD patients. Conclusions: Although diverse approaches have been used for AD cases of various events, the current meta-analysis indicates that that glaucoma patients have a higher AD risk.

Background: Excessive scar tissue can reduce postoperative survival of filtering blebs in patients with glaucoma. Previous studies have highlighted the role of chloride channels in wound healing. whereas The role of chloride channels in the formation of follicular scar has not been studied. Objectives: To investigate the effects of the ClC-2 chloride channel on scar formation of filtering blebs after glaucoma filtering surgery. Methods: We Inhibited ClC-2 chloride channels of Human Conjunctival Fibroblasts (HConFs) by transfecting HConFs with ClC-2 siRNA, Then cell proliferation, cycle and collagen synthesis of HConFs were measured. ClC-2 siRNA-transfected HConFs were cultured in type I collagen gels in the presence of transforming growth factor (TGF)-β1. Collagen gel contraction was evaluated based on the gel area. The expression levels of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in HConFs were assessed by western blotting and q-PCR. Results: TGF-β1induced cell proliferation, cell cycle progression, collagen synthesis, and collagen gel contraction in HConFs. TGF-β1 increased MMP-2 and MMP-9 levels but inhibited the expression of TIMPs. ClC-2 siRNA transfection inhibited TGF-β1-induced cell proliferation, cell cycle progression, collagen synthesis, and collagen gel contraction, mediated by HConFs. TGF-β1-induced increases in MMP-2 and MMP-9 were also inhibited by NPPB and ClC-2 siRNA transfection, but TIMP expression was increased by ClC-2 siRNA transfection. Conclusions: These findings demonstrate that ClC-2 gene knockout inhibited TGF-β1-induced cell proliferation, collagen synthesis, and collagen gel contraction of HConFs by attenuating MMP-2 and MMP-9 production and by stimulating TIMP-1 production. Keywords: ClC-2 chloride channel; conjunctival fibroblasts; TGF-β1; wound heal

Background: This study aimed to investigate the regulation of chloride channels in proliferative vitreoretinopathy (PVR) both in vitro and in vivo using a rabbit model and to explore the underlying mechanism. Methods: The chloride channel is regulated by the chloride channel inhibitor 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) and the chloride channel activator lubiprostone. CCK-8, cell scratch, and Transwell assays assessed retinal pigment epithelium (RPE) cell proliferation and migration. Changes in the expression of the extracellular matrix proteins CollagenI, CollagenIII, fibronectin and α-SMA in ARPE19 cells were detected by Western blotting. In the in vivo study, NPPB or lubiprostone was injected intravitreally after the PVR model was established. The degree of traumatic PVR was evaluated and graded by observing the structures of the anterior segment, vitreous body, and fundus in rabbits. Results: Lubiprostone promoted transforming growth factor-β1 induced ARPE 19 cell growth and invasion, thereby facilitating PVR formation. In contrast, NPPB had the opposite effect, as it inhibited PVR formation. Consistent results were also observed in in vivo models. A novel therapeutic approach for treating PVR, which is based on chloride channels, was explored. Conclusion: By reducing the opening of chloride channels within RPE cells via drugs, PVR formation can be suppressed, which is sufficient to counteract retinal degeneration. Chloride channels may have crucial effects on RPE cell proliferation and migration. The therapeutic strategy of blocking chloride channels may be beneficial for PVR.

Filtration surgery is commonly performed for glaucoma treatment to reduce intraocular pressure (IOP); however, scarring of the filtering bleb is the main cause of failure. In this study, we evaluated the effects of the chloride channel blocker 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB) on scar formation in filtering blebs. A glaucoma filtering surgery model was generated using Sprague-Dawley rats, divided into the control and NPPB groups receiving injections of different NPPB concentrations. The IOP of all rats decreased 1-day post-surgery and gradually increased afterward. However, IOP in rats from the NPPB groups recovered more slowly than that of the control group rats. In addition, the area and survival times of filtering blebs in rats from the NPPB groups were substantially larger and longer than those in the control group. Twenty-eight days after surgery, the protein and mRNA expression of collagen I, fibronectin and & alpha;-smooth muscle actin in the filtering area of rats from the NPPB groups were significantly lower than that in the control group rats. Collectively, our study demonstrates that NPPB inhibits filtering bleb scar formation, maintains filtering bleb morphology and prolongs filtering bleb survival time by inhibiting the differentiation of conjunctival fibroblasts and extracellular matrix synthesis.