Diabetic retinopathy (DR) is an important microvascular complication of type 1 and type 2 diabetes mellitus (DM) and a major cause of blindness. Retinal neovascularization plays a critical role in the proliferative DR. In this study, high glucose-induced connexin 43 (Cx43) expression in human retinal endothelial cells (hRECs) in a dose-dependent manner. Compared with hRECs under normal culture conditions, high-glucose (HG)-stimulated hRECs showed promoted tubule formation, increased ROS release, and elevated levels of tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), vascular endothelial growth factor A (VEGFA), and intercellular adhesion molecule 1 (ICAM-1) in the culture medium. HG-induced alterations were further magnified after Cx43 overexpression, whereas partially eliminated after Cx43 knockdown. Finally, in the DR mouse model, impaired retinal structure, increased CD31 expression, and elevated mRNA levels of TNF-α, IL-1β, VEGFA, and ICAM-1 were observed; in-vivo Cx43 knockdown partially reversed these phenomena. Conclusively, Cx43 knockdown could inhibit hREC angiogenesis, therefore improving DR in the mouse model.

Background Autoimmune blistering skin diseases (AIBD) are a group of rare chronic autoimmune diseases which are associated with ocular surface diseases especially dry eye disease. This study is designed to investigate the relationship between ocular surface disorders and quality of life among patients with autoimmune blistering skin diseases. Methods Twenty-four AIBD patients (18 pemphigus and 7 pemphigoid) and twenty-five non-AIBD controls were included. Ocular surface disease index (OSDI), ocular surface evaluation, including slit-lamp examination, Schirmer I test, tear break-up time, corneal fluorescein staining, lid-parallel conjunctival folds, meibomian gland evaluation, presence of symblepharon and corneal opacity were assessed. Life quality was evaluated by multiple questionnaires, including Medical Outcomes Study 36-Item Short Form Questionnaire (SF-36), Hospital Anxiety and Depression Scale (HADS), Pittsburgh Sleep Quality Index (PSQI) and Health Assessment Questionnaire-Disability Index (HAQ-DI). Ocular surface tests and quality of life were compared between AIBD patients and non-AIBD controls. In the AIBD patients, the associations between ocular surface parameters and quality of life were also evaluated. Results 92% of AIBD patients and 87.5% of age- and sex-matched non-AIBD controls were diagnosed with dry eye in this study. Compared with non-AIBD controls, AIBD patients reported lower SF-36 scores (P < 0.05) and severer OSDI, Schirmer I test, tear break-up time, corneal fluorescein staining, presence of symblepharon and corneal opacity measures (P < 0.05). OSDI, Schirmer I test were correlated with SF-36 composite scores or scores on the SF-36 subscales. Conclusions AIBD patients experience reduced quality of life and more severe ocular surface disorders including dry eye, symblepharon and corneal opacity. Early treatments of dry eye and collaborations among multidisciplinary physicians are necessary in patients with AIBD.