Metabolic stress response implicated in diabetic retinopathy: The role of calpain, and the therapeutic impact of calpain inhibitor.
Metabolic stress response implicated in diabetic retinopathy: The role of calpain, and the therapeutic impact of calpain inhibitor.
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糖尿病视网膜病变涉及的代谢应激反应：钙蛋白酶的作用以及钙蛋白酶抑制剂的治疗影响。
DOI：
10.1016/j.nbd.2012.07.025
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Yamamoto M.
中科院分区：
文献类型：
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作者：
Shanab AY;Nakazawa T;Ryu M;Tanaka Y;Himori N;Taguchi K;Ysuda M;Watanabe R;Takano J;Saido T;Minegishi N;Miyata T;Abe T;Yamamoto M.
为了描述高脂肪饮食 (HFD) 和高血糖如何引发与糖尿病视网膜病变 (DR) 神经退行性变化相关的一系列钙蛋白酶激活和氧化应激，在缺乏钙蛋白酶抑制剂基因 (CAST KO) 的小鼠和缺乏转录因子 NF-E2 相关因子 2 (Nrf2 KO) 基因的小鼠中用链脲佐菌素诱导高血糖。所有动物均喂食 HFD。通过荧光金标记和免疫组织化学来估计视网膜神经节细胞（RGC）密度。每天给予强效钙蛋白酶抑制剂 SNJ-1945，直至处死动物。在体外，在含有和不含 SNJ-1945 的高葡萄糖培养基中评估氧化应激诱导的 RGC 损失。通过定量 RT-PCR 测量视网膜 calpain-1 和 calpain-2 的 mRNA。通过免疫印迹分析对裂解的 α-fodrin 和突触素蛋白的凋亡前底物进行定量。在视神经横切面检查轴突损伤。实验进行 3 周后，HFD 和高血糖显着增加了 RGC 和轴突变性。裂解的α-胞质蛋白的水平增加。在 CAST KO 小鼠中，神经毒性显着增强。 CAST 基因操作和口服 SNJ-1945 成功改变了视网膜中的钙蛋白酶水平并防止了 RGC 死亡。在体外，不使用抗氧化剂的视网膜细胞高葡萄糖培养物显示出比使用抗氧化剂处理的视网膜细胞更多的 RGC 死亡。 SNJ-1945 处理显着抑制突触素的表达。这些结果表明钙蛋白酶在高血糖和氧化应激引起的代谢诱导的 RGC 变性中起着至关重要的作用。抗氧化剂和钙蛋白酶抑制为未来针对各种代谢应激诱发疾病（包括 DR）中 RGC 死亡的神经保护治疗提供了重要机会。
To describe how a high fat diet (HFD) and hyperglycemia initiate a sequence of calpain activation and oxidative stress associated with neuro-degenerative changes in diabetic retinopathy (DR), hyperglycemia was induced with streptozotocin in mice lacking the gene for calpastatin (CAST KO), and in mice lacking the gene for the transcription factor NF-E2 related factor 2 (Nrf2 KO). All animals were fed a HFD. Retinal ganglion cell (RGC) density was estimated by labeling with fluorogold and immunohistochemistry. A potent calpain inhibitor, SNJ-1945, was administered daily until the animals were sacrificed. In vitro, oxidative stress-induced RGC loss was evaluated in a high glucose culture medium with and without SNJ-1945. Retinal mRNA of calpain-1 and calpain-2 was measured by quantitative RT-PCR. Pre-apoptotic substrates of cleaved α-fodrin and synaptophysin protein were quantified by immunoblot analysis. Axonal damage was examined in transverse sections of the optic nerve. A HFD and hyperglycemia significantly increased RGC and axonal degeneration 3weeks into the experiment. Levels of cleaved α-fodrin were increased. In the CAST KO mice, the neurotoxicity was augmented significantly. Gene manipulation of CAST and orally administered SNJ-1945 successfully modified calpain levels in the retina and prevented RGC death. In vitro, a high-glucose culture of retinal cells without antioxidants showed more RGC death than that with antioxidant treatment. The expression of synaptophysin was significantly suppressed by SNJ-1945 treatment. These results suggest that calpain plays a crucial role in metabolic-induced RGC degeneration caused by hyperglycemia and oxidative stress. Antioxidant and calpain inhibition offers important opportunities for future neuroprotective treatment against RGC death in various metabolic stress-induced diseases including DR.