Data from: Potential role of Cyr61 induced degeneration of human Müller cells in diabetic retinopathy

The degeneration of Müller cells has been recognized to involve in the pathogenesis of diabetic retinopathy. However, the mechanism is not yet clear. This study is to explore the potential role of Cyr61, a secreted signaling protein in extracellular matrix, in inducing human Müller cell degeneration in diabetic retinopathy (DR). Twenty patients with proliferative diabetic retinopathy (PDR) and twelve non-diabetic patients were recruited for this study. Vitreous fluid was collected during vitrectomy surgery for Cyr61 ELISA. Human Müller cell line MIO-M1 were cultured to be subconfluent, and then treated with glucose (0–20 mM) or Cyr61 (0–300 ng/ml). Cyr61 expression induced by increasing concentrations of glucose was evaluated by RT-qPCR and Western blot. Effects of Cyr61 on Müller cells viability, migration and apoptosis were observed by MTT assay, Transwell assay, and TUNEL assay. Vitreous Cyr61 levels were observed to be 8-fold higher in patients with PDR (3576.92±1574.58 pg/mL), compared with non-diabetic controls (436.14±130.69 pg/mL). Interestingly, the active PDR group was significantly higher than the quiescent PDR group (P<0.01). In retinal Müller cells culture, high glucose significantly and dose-dependently elevated Cyr61 expression at both mRNA and protein levels. Cyr61 at high concentrations dose-dependently inhibited the viability and migration of Müller cells. TUNEL assay further revealed that high concentration of Cyr61 significantly promoted the cell apoptosis. In conclusion, these findings demonstrated for the first time that the expression of Cyr61 was elevated by high glucose in Müller cells, and Cyr61 inhibited cell viability and migration while induced apoptosis, suggesting the potential role of Cyr61 in Müller cell degeneration. The elevated Cyr61 levels in vitreous fluid of PDR patients further support its role in diabetic retinopathy (DR).

Müller细胞（Müller cells）的变性已被证实参与糖尿病视网膜病变（diabetic retinopathy, DR）的发病机制，但其具体分子机制尚未阐明。本研究旨在探讨细胞外基质中的分泌型信号蛋白Cyr61在糖尿病视网膜病变中诱导人Müller细胞变性的潜在作用。本研究共纳入20例增殖性糖尿病视网膜病变（proliferative diabetic retinopathy, PDR）患者与12例非糖尿病患者作为对照。收集患者玻璃体切割术中的玻璃体液，采用酶联免疫吸附实验（ELISA）检测Cyr61水平。将人Müller细胞系MIO-M1培养至亚汇合状态，分别用浓度梯度为0~20 mM的葡萄糖或0~300 ng/ml的Cyr61进行处理。通过实时定量聚合酶链反应（RT-qPCR）与蛋白质印迹（Western blot）检测高糖诱导下Cyr61的表达水平。采用MTT法、Transwell实验与TUNEL实验分别检测Cyr61对Müller细胞活力、迁移能力及凋亡的影响。检测结果显示，PDR患者玻璃体液中Cyr61水平为3576.92±1574.58 pg/mL，较非糖尿病对照组的436.14±130.69 pg/mL升高8倍；值得注意的是，活动性PDR组患者的玻璃体Cyr61水平显著高于静止性PDR组（P<0.01）。在体外视网膜Müller细胞培养体系中，高糖可呈剂量依赖性地显著上调Cyr61的mRNA与蛋白表达水平。高浓度Cyr61可呈剂量依赖性抑制Müller细胞的活力与迁移能力；TUNEL实验进一步证实，高浓度Cyr61可显著促进细胞凋亡。综上，本研究首次证实高糖可上调Müller细胞中Cyr61的表达，而Cyr61可抑制Müller细胞的活力与迁移能力并诱导细胞凋亡，提示Cyr61在Müller细胞变性过程中发挥潜在作用。PDR患者玻璃体液中升高的Cyr61水平进一步支持其在糖尿病视网膜病变中的病理意义。