Division of Nephrology, Department of Medicine, Stony Brook University, Stony Brook, NY.
Department of Pathology, University of Utah, Salt Lake City, UT.
Diabetes. 2018 Nov;67(11):2420-2433. doi: 10.2337/db17-0958. Epub 2018 Aug 16.
Mitochondrial injury is uniformly observed in several murine models as well as in individuals with diabetic kidney disease (DKD). Although emerging evidence has highlighted the role of key transcriptional regulators in mitochondrial biogenesis, little is known about the regulation of mitochondrial cytochrome c oxidase assembly in the podocyte under diabetic conditions. We recently reported a critical role of the zinc finger Krüppel-like factor 6 (KLF6) in maintaining mitochondrial function and preventing apoptosis in a proteinuric murine model. In this study, we report that podocyte-specific knockdown of increased the susceptibility to streptozotocin-induced DKD in the resistant C57BL/6 mouse strain. We observed that the loss of in podocytes reduced the expression of with resultant increased mitochondrial injury, leading to activation of the intrinsic apoptotic pathway under diabetic conditions. Conversely, mitochondrial injury and apoptosis were significantly attenuated with overexpression of in cultured human podocytes under hyperglycemic conditions. Finally, we observed a significant reduction in glomerular and podocyte-specific expression of KLF6 in human kidney biopsies with progression of DKD. Collectively, these data suggest that podocyte-specific KLF6 is critical to preventing mitochondrial injury and apoptosis under diabetic conditions.
线粒体损伤在几种小鼠模型以及糖尿病肾病 (DKD) 患者中均普遍观察到。虽然新出现的证据强调了关键转录调节因子在线粒体生物发生中的作用,但对于糖尿病条件下足细胞中线粒体细胞色素 c 氧化酶组装的调节知之甚少。我们最近报道了锌指 Krüppel 样因子 6 (KLF6) 在维持线粒体功能和防止蛋白尿小鼠模型中细胞凋亡方面的关键作用。在这项研究中,我们报告说,在抵抗性 C57BL/6 小鼠品系中,足细胞特异性敲低 增加了对链脲佐菌素诱导的 DKD 的易感性。我们观察到,足细胞中 的缺失降低了 的表达,导致糖尿病条件下线粒体损伤增加,进而激活内在凋亡途径。相反,在高血糖条件下,过表达 可显著减轻培养的人足细胞中的线粒体损伤和凋亡。最后,我们在进展性 DKD 的人类肾活检中观察到肾小球和足细胞特异性 KLF6 表达显著减少。总之,这些数据表明,足细胞特异性 KLF6 对于预防糖尿病条件下的线粒体损伤和凋亡至关重要。