Department of Nephrology, Xiangya Hospital Central South University, Changsha, China.
Department of Integrated Chinese and Western Medicine, Xiangya Hospital Central South University, Changsha, China.
Clin Exp Pharmacol Physiol. 2023 Jun;50(6):504-515. doi: 10.1111/1440-1681.13767. Epub 2023 Mar 26.
Podocyte loss is a predictor of kidney disease development, including diabetic nephropathy. Astragalus polysaccharide (APS) was considered a renoprotective drug, whereas the mechanisms operated by APS on podocyte dysfunction are rarely mentioned. This study aims at the mechanistic underlying of APS on angiotensin II (Ang II)-induced podocyte dysfunction. Mouse glomerular podocytes MPC5 were induced with Ang II, the morphologic changes were observed and nephrin, desmin and Wilms' tumour protein-1 (WT-1) levels were determined. The MPC5 cells were treated with APS (50, 100 and 200 μg/mL) and transduced with retinoic acid receptor responder protein 1 (RARRES1) overexpression vectors. The expression of RARRES1, lipocalin-2 (LCN2), nephrin and desmin was tested, MPC5 cell viability and apoptosis were evaluated, and the levels of an endocytotic receptor megalin, Bcl-2, Bax, interleukin (IL)-6, IL-1β and tumour necrosis factor (TNF)-α were assessed. The binding of RARRES1 to LCN2 was predicted and verified. Mice were infused with Ang II to evaluate histopathological alterations and 24-h urinary albumin content. Ang II induction suppressed MPC5 cell viability, reduced the expression of nephrin, WT-1, megalin and Bcl-2, and augmented the expression of desmin, Bax, IL-6, IL-1β and TNF-α, which were significantly nullified by APS treatment. RARRES1 interacted with LCN2, and APS treatment inhibited RARRES1 and LCN2 expression in a dose-dependent manner, thereby alleviating Ang II-induced podocyte dysfunction. Ang II infusion in mice facilitated pathological alterations in renal tissues and increased urinary albumin content, which were attenuated after APS treatment. Overall, APS treatment alleviated Ang II-induced podocyte dysfunction by inhibiting RARRES1/LCN2 expression and blocked kidney injury development in vivo.
足细胞丢失是肾脏疾病发展的预测因子，包括糖尿病肾病。黄芪多糖（APS）被认为是一种肾保护药物，而 APS 对足细胞功能障碍的作用机制很少被提及。本研究旨在探讨 APS 对血管紧张素 II（Ang II）诱导的足细胞功能障碍的作用机制。用 Ang II 诱导小鼠肾小球足细胞 MPC5，观察其形态变化，测定nephrin、desmin 和 Wilms 瘤蛋白-1（WT-1）水平。用 APS（50、100 和 200μg/ml）处理 MPC5 细胞，并转染维甲酸受体应答蛋白 1（RARRES1）过表达载体。检测 RARRES1、脂联素（LCN2）、nephrin 和 desmin 的表达，评估 MPC5 细胞活力和凋亡，并检测内吞受体 megalin、Bcl-2、Bax、白细胞介素（IL）-6、IL-1β 和肿瘤坏死因子（TNF）-α的水平。预测并验证了 RARRES1 与 LCN2 的结合。用 Ang II 灌注小鼠以评估组织病理学改变和 24 小时尿白蛋白含量。Ang II 诱导抑制 MPC5 细胞活力，降低 nephrin、WT-1、megalin 和 Bcl-2 的表达，增加 desmin、Bax、IL-6、IL-1β 和 TNF-α的表达，APS 治疗可显著减轻这些变化。RARRES1 与 LCN2 相互作用，APS 治疗呈剂量依赖性抑制 RARRES1 和 LCN2 的表达，从而缓解 Ang II 诱导的足细胞功能障碍。Ang II 灌注小鼠可促进肾脏组织的病理改变并增加尿白蛋白含量，APS 治疗可减轻这些改变。综上所述，APS 治疗通过抑制 RARRES1/LCN2 表达缓解 Ang II 诱导的足细胞功能障碍，并在体内阻止肾脏损伤的发展。
