Cell Electrophysiology Laboratory, Wannan Medical College, Wuhu, China.
Ren Fail. 2022 Dec;44(1):1780-1790. doi: 10.1080/0886022X.2022.2134796.
Glomerular mesangial cell (GMC) dysfunction plays a vital role in the pathogenesis of diabetic kidney disease (DKD). Transient receptor potential canonical 6 (TRPC6) has been demonstrated to be involved in the development of DKD. However, the underlying mechanism remains unclear. The present study investigated the role of TRPC6 in GMC dysfunction and the related mechanism.
Diabetic rats and cultured GMCs were used in the experiment. The diabetic rat model was created by intraperitoneal injection of streptozotocin. Protein and mRNA levels were assessed by Western blotting and quantitative RT-PCR, respectively. Histological changes in the kidneys were observed by immunochemistry and hematoxylin and eosin. TRPC6 knockdown was achieved by adenovirus-mediated TRPC6 shRNA delivery and TRPC6 siRNA transfection .
TRPC6 expression was increased in diabetic rat kidneys. Knockdown of TRPC6 attenuated diabetes-induced kidney functional deterioration. In addition, the increases in extracellular matrix components, including collagen IV, collagen I, and fibronectin production, as well as NFAT2 expression were also suppressed. In cultured GMCs, high glucose (25 mM, HG) treatment increased the expression of TRPC6. Knockdown of TRPC6 alleviated HG-induced increases in collagen IV, fibronectin, and NFAT2 expression. Knockdown of NFAT2 also inhibited the upregulation of proteins, including collagen IV and fibronectin, in HG-treated GMCs.
These results demonstrate that inhibition of TRPC6/NFAT2 signaling attenuates GMC dysfunction and the development of DKD and suggest that pharmacological targeting of TRPC6/NFAT2 in GMCs may provide beneficial effects for DKD.
肾小球系膜细胞（GMC）功能障碍在糖尿病肾病（DKD）发病机制中起着至关重要的作用。瞬时受体电位经典型 6（TRPC6）已被证明参与了 DKD 的发展。然而，其潜在机制尚不清楚。本研究探讨了 TRPC6 在 GMC 功能障碍中的作用及其相关机制。
实验中使用了糖尿病大鼠和培养的 GMC。通过腹腔注射链脲佐菌素建立糖尿病大鼠模型。通过 Western blot 和定量 RT-PCR 分别评估蛋白和 mRNA 水平。通过免疫组织化学和苏木精和伊红染色观察肾脏的组织学变化。通过腺病毒介导的 TRPC6 shRNA 递送和 TRPC6 siRNA 转染实现 TRPC6 敲低。
TRPC6 在糖尿病大鼠肾脏中的表达增加。TRPC6 敲低减轻了糖尿病引起的肾脏功能恶化。此外，还抑制了细胞外基质成分（包括胶原 IV、胶原 I 和纤连蛋白的产生）和 NFAT2 表达的增加。在培养的 GMC 中，高葡萄糖（25mM，HG）处理增加了 TRPC6 的表达。TRPC6 敲低减轻了 HG 诱导的胶原 IV、纤连蛋白和 NFAT2 表达增加。NFAT2 的敲低也抑制了 HG 处理的 GMC 中包括胶原 IV 和纤连蛋白在内的蛋白的上调。
这些结果表明，抑制 TRPC6/NFAT2 信号通路可减轻 GMC 功能障碍和 DKD 的发展，并表明靶向 GMC 中的 TRPC6/NFAT2 可能对 DKD 具有有益作用。
