Inhibition of connective tissue growth factor overexpression in diabetic retinopathy by SERPINA3K via blocking the WNT/beta-catenin pathway.
Inhibition of connective tissue growth factor overexpression in diabetic retinopathy by SERPINA3K via blocking the WNT/beta-catenin pathway.
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作者：
Zhang B;Zhou KK;Ma JX
结缔组织生长因子（CTGF）是一种主要的纤维化因子。视网膜CTGF水平的增加与糖尿病视网膜病变有关。SERPINA 3 K是一种丝氨酸蛋白酶抑制剂，其水平在糖尿病视网膜病变视网膜中降低。本研究旨在探讨SERPINA 3 K在CTGF和纤维化发生中的调节作用及其作用机制。将表达SERPINA 3 K的腺病毒注射到链脲佐菌素诱导的糖尿病大鼠中。CTGF表达采用Western blot分析和实时RT-PCR测定。通过使用酶联免疫吸附测定定量视网膜纤维连接蛋白来评估纤维化。Wnt通路的激活通过LDL受体相关蛋白6（Wnt配体的辅助受体）的磷酸化和β-连环蛋白（经典Wnt通路的重要效应物）的稳定化来确定。Ad-SERPINA 3 K可抑制糖尿病大鼠视网膜CTGF和FN的过度表达。在培养的视网膜细胞中，SERPINA 3 K阻断高糖诱导的CTGF过度产生。Dickkopf-1是一种特异性Wnt拮抗剂，也减弱了高糖诱导的CTGF过表达，表明Wnt信号在糖尿病CTGF过表达中的作用。类似地，增加SERPINA 3 K阻断糖尿病视网膜和高糖处理细胞中的Wnt通路活化。此外，SERPINA 3 K还减弱了Wnt 3a诱导的经典Wnt途径的激活和CTGF的过表达。SERPINA 3 K是一种抗纤维化因子，其抗纤维化活性是通过阻断Wnt通路实现的。SERPINA 3 K水平的降低可能有助于糖尿病视网膜病变中的纤维化。
Connective tissue growth factor (CTGF) is a major fibrogenic factor. Increased retinal CTGF levels have been implicated to play a role in diabetic retinopathy. SERPINA3K is a serine proteinase inhibitor, and its levels were decreased in retinas with diabetic retinopathy. The purpose of this study was to investigate the role of SERPINA3K in the regulation of CTGF and fibrogenesis and its mechanism of action. Adenovirus expressing SERPINA3K was injected intravitreally into streptozotocin-induced diabetic rats. CTGF expression was measured using Western blot analysis and real-time RT-PCR. Fibrosis was evaluated by quantifying retinal fibronectin using enzyme-linked immunosorbent assay. Wnt pathway activation was determined by phosphorylation of LDL receptor–related protein 6, a coreceptor of Wnt ligands, and stabilization of β-catenin, an essential effector of the canonical Wnt pathway. Ad-SERPINA3K attenuated the CTGF and fibronectin overexpression in retinas of diabetic rats. In cultured retinal cells, SERPINA3K blocked the overproduction of CTGF induced by high glucose. Dickkopf-1, a specific Wnt antagonist, also attenuated the high-glucose–induced CTGF overexpression, indicating a role of Wnt signaling in CTGF overexpression in diabetes. Similarly, increased SERPINA3K blocked Wnt pathway activation in diabetic retinas and in cells treated with high glucose. Further, SERPINA3K also attenuated the Wnt3a-induced activation of the canonical Wnt pathway and the overexpression of CTGF. SERPINA3K is an antifibrogenic factor, and its antifibrogenic activity is through blocking the Wnt pathway. Decreased SERPINA3K levels may contribute to the fibrosis in diabetic retinopathy.