Division of Nephrology, Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, P.R. China.
Division of Nephrology, Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, P.R. China,
Arch Endocrinol Metab. 2023 Jun 19;67(6):e000643. doi: 10.20945/2359-3997000000643.
The incidence of diabetic nephropathy (DN) is gradually increasing worldwide. Podocyte injury, such as podocyte apoptosis and loss of the slit diaphragm (SD)-specific markers are early pathogenic features of DN.
The cultured mouse podocytes were separated into a high glucose-treated (HG, 30mM) group to mimic DN , a low glucose-treated (LG, 5mM) group as a control and HG+ angiotensin-(1-7)(Ang-(1-7)) and HG+Ang-(1-7) + D-Ala7-Ang-(1-7) (A779, Ang-(1-7)/Mas receptor antagonist) experimental groups. The Cell Counting Kit-8 (CCK-8) method and flow cytometry was used to detect podocyte activity and podocyte apoptosis respectively. The expression of angiotensin type 1 receptor (AT1R), Mas receptor (MasR) and podocyte-specific markers were examined by q-PCR and Western blot, respectively.
The results showed that the decrease in podocyte activity; the increase in podocyte apoptosis; the decreased mRNA and protein expression of nephrin, podocin, WT-1 and MasR; and the upregulated expression of AT1R induced by HG could be reversed by Ang-(1-7). However, these effects were blocked by A779. The possible mechanisms of the Ang-(1-7)-mediated effect depended on MasR. In addition, the protective effect of Ang-(1-7) on podocyte activity was dose-dependent and most obvious at 10 µM. A779 had the greatest antagonistic action against Ang-(1-7) at a concentration of 10 μM.
This study reveals that binding of Ang-(1-7) to its specific receptor MasR may counteract the effects of Ang II mediated by AT1R to significantly attenuate podocyte injury induced by high glucose. Ang-(1-7)/MasR targeting in podocytes may be a therapeutic approach to attenuate renal injury in DN.
糖尿病肾病（DN）的发病率在全球范围内逐渐升高。足细胞损伤，如足细胞凋亡和裂孔隔膜（SD）特异性标志物的丢失，是 DN 的早期发病特征。
将培养的小鼠足细胞分离为高糖处理（HG，30mM）组以模拟 DN，低糖处理（LG，5mM）组作为对照，以及 HG+血管紧张素-(1-7)（Ang-(1-7)）和 HG+Ang-(1-7)+D-Ala7-Ang-(1-7)（A779，Ang-(1-7)/Mas 受体拮抗剂）实验组。使用细胞计数试剂盒-8（CCK-8）法和流式细胞术分别检测足细胞活性和足细胞凋亡。通过 q-PCR 和 Western blot 分别检测血管紧张素 1 型受体（AT1R）、Mas 受体（MasR）和足细胞特异性标志物的表达。
结果表明，HG 诱导的足细胞活性降低；足细胞凋亡增加；nephrin、podocin、WT-1 和 MasR 的 mRNA 和蛋白表达减少；以及 AT1R 的表达上调，均可被 Ang-(1-7)逆转。然而，这些作用被 A779 阻断。Ang-(1-7)介导的作用的可能机制依赖于 MasR。此外，Ang-(1-7)对足细胞活性的保护作用呈剂量依赖性，在 10µM 时最明显。A779 在 10μM 时对 Ang-(1-7)的拮抗作用最大。
本研究表明，Ang-(1-7)与特异性受体 MasR 的结合可能拮抗由 AT1R 介导的 Ang II 的作用，从而显著减轻高糖诱导的足细胞损伤。足细胞中 Ang-(1-7)/MasR 的靶向可能是减轻 DN 肾损伤的一种治疗方法。
