Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan.
Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, 35-2 Sakae-cho, Itabashi-ku, Tokyo, 173-0015, Japan; Department of Bioscience and Engineering, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama, 337-8570, Japan.
Arch Biochem Biophys. 2019 Dec 15;678:108167. doi: 10.1016/j.abb.2019.108167. Epub 2019 Nov 5.
The Goto-Kakizaki (GK) rat is a spontaneous animal model of type 2 diabetes and early stage of diabetic nephropathy. However, the pathophysiological mechanisms contributing to the progression of diabetic nephropathy in GK rats remain unclear. Kidneys from 15-week old male diabetic GK/Jcl rats and age-matched Wistar rats, which have the same genetic background as GK rats, were used. Proteomic analyses of GK and Wistar kidneys were performed using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE). Differentially expressed proteins in GK rats were subjected to pathway analysis, and expression levels of hypoxia inducible factor 1α (HIF-1α) and transforming growth factor-β1 (TGF-β1), and fumarate accumulation in GK kidneys were examined. Azan staining and immunohistochemical staining of α-smooth muscle actin were performed in relation to fibrosis in GK kidneys. Proteomic analysis using 2D-DIGE, analysis of fumarate content, and expression analysis of HIF-1α, TGF-β1, and α-smooth muscle actin of GK rat's kidney, suggested the mechanism of fibrosis characterized as two stages in diabetic nephropathy of GK rats. Abnormalities of glucose metabolism such as elevated levels of 2-oxoglutarate dehydrogenase and reduction of fumarate hydratase caused the accumulation of fumarate followed by the upregulation of HIF-1α and TGF-β1 leading to fibrosis in diabetic nephropathy. Alterations in proteins involved in the tricarboxylic acid cycle are associated with fibrosis through fumarate accumulation in diabetic nephropathy of GK rats.
Goto-Kakizaki (GK) 大鼠是 2 型糖尿病和糖尿病肾病早期阶段的自发性动物模型。然而，导致 GK 大鼠糖尿病肾病进展的病理生理机制仍不清楚。使用 15 周龄雄性糖尿病 GK/Jcl 大鼠和年龄匹配的具有与 GK 大鼠相同遗传背景的 Wistar 大鼠的肾脏进行蛋白质组学分析。使用二维荧光差异凝胶电泳（2D-DIGE）对 GK 和 Wistar 肾脏的蛋白质组进行分析。对 GK 大鼠中差异表达的蛋白质进行途径分析，并检测 HIF-1α（缺氧诱导因子 1α）和 TGF-β1（转化生长因子-β1）的表达水平以及 GK 肾脏中的富马酸积累。与 GK 肾脏纤维化有关，进行了阿赞染色和α-平滑肌肌动蛋白的免疫组织化学染色。通过 2D-DIGE 的蛋白质组学分析、富马酸含量分析以及 GK 大鼠肾脏中 HIF-1α、TGF-β1 和α-平滑肌肌动蛋白的表达分析，提示了 GK 大鼠糖尿病肾病纤维化的两个阶段的机制。葡萄糖代谢异常，如 2-氧戊二酸脱氢酶水平升高和富马酸水合酶减少，导致富马酸积累，随后 HIF-1α 和 TGF-β1 上调，导致糖尿病肾病纤维化。三羧酸循环中涉及的蛋白质的改变通过 GK 大鼠糖尿病肾病中的富马酸积累与纤维化有关。
