Division of Nephrology, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, P.R. China.
Mol Med Rep. 2018 Mar;17(3):4589-4598. doi: 10.3892/mmr.2018.8386. Epub 2018 Jan 5.
Obesity-related glomerulopathy (ORG) is morphologically characterized by glomerulomegaly with or without observable focal segmental glomerulosclerosis under light microscope, with decreased podocyte density and number, and with increased foot‑process width observed under electron microscope. The severity of podocyte injury is correlated with the degree of proteinuria and renal dysfunction. However, the pathogenesis of ORG is not well understood. The aim of the present study was to explore the possible pathogenic role of aldosterone (ALDO) in ORG. In the in vivo animal experiments, body weight, Lee's obesity index, abdominal fat index, urinary protein excretion, average glomerular diameter were significantly increased, the mRNA and protein expression of podocyte‑associated molecules including nephrin, podocin, podoplanin and podocalyxin were significantly reduced, and the Wnt/β‑catenin signaling pathway was activated in ORG model mice compared with the Control mice, whereas the administration of spironolactone significantly ameliorated these effects. In the in vitro experiments on cultured podocytes, the mRNA and protein expression levels of the aforementioned podocyte‑associated molecules were significantly downregulated and the Wnt/β‑catenin signaling pathway was activated following ALDO stimulation, whereas eplerenone significantly attenuated all the above effects. Dickkopf‑related protein 1 (DKK1), an inhibitor of Wnt/β‑catenin signaling pathway, also reduced the effects of ALDO exposure on the expression of podocyte‑associated molecules. The present study hypothesized that ALDO may be involved in the pathogenesis of ORG through the activation of Wnt/β‑catenin signaling pathway in podocytes.
肥胖相关性肾小球病(ORG)在形态学上的特征是肾小球肿大,光镜下可见或不可见局灶节段性肾小球硬化,电镜下可见足细胞密度和数量减少,足突宽度增加。足细胞损伤的严重程度与蛋白尿和肾功能不全的程度相关。然而,ORG 的发病机制尚不清楚。本研究旨在探讨醛固酮(ALDO)在 ORG 中的可能致病作用。在体内动物实验中,与对照组小鼠相比,ORG 模型小鼠的体重、Lee 肥胖指数、腹部脂肪指数、尿蛋白排泄量、平均肾小球直径显著增加,足细胞相关分子(包括nephrin、podocin、podoplanin 和 podocalyxin)的 mRNA 和蛋白表达显著降低,Wnt/β-catenin 信号通路被激活,而螺内酯的给药显著改善了这些作用。在体外培养的足细胞实验中,ALDO 刺激后,上述足细胞相关分子的 mRNA 和蛋白表达水平显著下调,Wnt/β-catenin 信号通路被激活,而依普利酮显著减弱了所有上述作用。Wnt/β-catenin 信号通路抑制剂 Dickkopf 相关蛋白 1(DKK1)也降低了 ALDO 暴露对足细胞相关分子表达的影响。本研究假设 ALDO 可能通过激活足细胞中的 Wnt/β-catenin 信号通路参与 ORG 的发病机制。