Reduced Connexin 43 Expression and Its Effect on the Development of Vascular Lesions in Retinas of Diabetic Mice
Reduced Connexin 43 Expression and Its Effect on the Development of Vascular Lesions in Retinas of Diabetic Mice
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DOI：
10.1167/iovs.09-4489
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发表时间：
2010-07-01
影响因子：
4.4
通讯作者：
Roy, Sayon
中科院分区：
文献类型：
--
作者：
Bobbie, Michael W.;Roy, Sumon;Roy, Sayon
目的.研究糖尿病诱导的连接蛋白43下调是否促进糖尿病视网膜病变（DR）特征性视网膜血管病变。研究了两种动物模型，链脲佐菌素诱导的糖尿病小鼠和Cx43杂合敲除（Cx43（+/-））小鼠，以直接评估糖尿病是否降低视网膜Cx43的表达，这反过来又有助于通过凋亡导致视网膜血管细胞损失。通过Western blot分析评估非糖尿病对照小鼠、糖尿病小鼠和Cx43（+/-）小鼠的视网膜Cx43蛋白水平，并通过视网膜胰蛋白酶抑制剂（RTD）的免疫染色研究Cx43在视网膜血管细胞中的定位和分布。同时，用苏木精和高碘酸希夫染色RTD以确定周细胞损失（PL）和无细胞毛细血管（AC），并进行TUNEL测定以确定视网膜血管细胞增生。Western印迹分析表明，与非糖尿病小鼠相比，糖尿病小鼠和Cx43（+/-）小鼠视网膜Cx43蛋白水平显著降低。类似地，与对照小鼠相比，在糖尿病小鼠和Cx43（+/-）小鼠的视网膜毛细血管中观察到Cx43免疫染色的显著减少。糖尿病小鼠和年龄匹配的Cx43（+/-）小鼠与对照小鼠相比，PL、AC和TUNEL阳性细胞数量增加。糖尿病诱导的Cx43表达抑制有助于糖尿病小鼠视网膜血管细胞凋亡。这表明Cx43表达减少在与DR相关的AC和PL的发展中起关键作用。2010;51：3758-3763）DOI：10.1167/iovs.09-4489
PURPOSE. To examine whether diabetes-induced connexin 43 downregulation promotes retinal vascular lesions characteristic of diabetic retinopathy (DR).METHODS. Two animal models, streptozotocin-induced diabetic mice and Cx43 heterozygous knockout (Cx43(+/-)) mice, were studied to directly assess whether diabetes reduces the expression of retinal Cx43, which, in turn, contributes to retinal vascular cell loss by apoptosis. Retinal Cx43 protein levels were assessed in nondiabetic control mice, diabetic mice, and Cx43(+/-) mice by Western blot analysis, and Cx43 localization and distribution in the retinal vascular cells were studied by immunostaining of retinal trypsin digests (RTDs). In parallel, RTDs were stained with hematoxylin and periodic acid Schiff to determine pericyte loss (PL) and acellular capillaries (AC), and TUNEL assays were performed to determine retinal vascular cell apoptosis.RESULTS. Western blot analysis indicated significant reductions in retinal Cx43 protein levels in diabetic mice and Cx43(+/-) mice compared with those of nondiabetic mice. Similarly, a significant reduction in Cx43 immunostaining was observed in the retinal capillaries of diabetic mice and Cx43(+/-) mice compared with those of control mice. Both diabetic and age-matched Cx43(+/-) mice exhibited increased amount of PL, AC, and TUNEL-positive cells compared with control mice.CONCLUSIONS. Diabetes-induced inhibition of Cx43 expression contributes to vascular cell apoptosis in retinas of diabetic mice. This suggests that reduced Cx43 expression plays a critical role in the development of AC and PL associated with DR. (Invest Ophthalmol Vis Sci. 2010;51:3758-3763) DOI:10.1167/iovs.09-4489