Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA.
Sci Rep. 2017 Mar 22;7(1):299. doi: 10.1038/s41598-017-00406-2.
Podocytes are becoming a primary focus of research efforts due to their association with progressive glomeruli damage in disease states. Loss of podocytes can occur as a result of excessive intracellular calcium influx, and we have previously shown that angiotensin II (Ang II) via canonical transient receptor potential 6 (TRPC6) channels caused increased intracellular Ca flux in podocytes. We showed here with patch-clamp electrophysiology that Ang II activates TRPC channels; then using confocal calcium imaging we demonstrated that Ang II-dependent stimulation of Ca influx in the podocytes is precluded by blocking either AT or AT receptors (ATRs). Application of Ang(1-7) had no effect on intracellular calcium. Ang II-induced calcium flux was decreased upon inhibition of TRPC channels with SAR7334, SKF 96365, clemizole hydrochloride and La, but not ML204. Using a novel 3D whole-glomerulus imaging ex vivo assay, we revealed the involvement of both ATRs in controlling glomerular permeability; additionally, using specific inhibitors and activators of TRPC6, we showed that these channels are implicated in the regulation of glomerular volume dynamics. Therefore, we provide evidence demonstrating the critical role of Ang II/TRPC6 axis in the control of glomeruli function, which is likely important for the development of glomerular diseases.
足细胞已成为研究工作的重点，因为它们与疾病状态下肾小球渐进性损伤有关。足细胞的丢失可能是由于细胞内钙流入过多所致，我们之前的研究表明血管紧张素 II（Ang II）通过经典瞬时受体电位 6（TRPC6）通道导致足细胞内 Ca 流增加。我们在这里通过膜片钳电生理学表明 Ang II 激活 TRPC 通道；然后，通过共聚焦钙成像，我们证明通过阻断 AT 或 AT 受体（ATRs）可以阻止 Ang II 依赖性的 Ca 流入到足细胞中。应用 Ang（1-7）对细胞内钙没有影响。用 SAR7334、SKF 96365、盐酸氯米唑和 La 抑制 TRPC 通道后，Ang II 诱导的钙流减少，但 ML204 没有。使用新型 3D 整体肾小球成像离体检测，我们揭示了 ATRs 都参与控制肾小球通透性；此外，使用 TRPC6 的特异性抑制剂和激活剂，我们表明这些通道参与了肾小球体积动力学的调节。因此，我们提供的证据表明 Ang II/TRPC6 轴在控制肾小球功能方面起着关键作用，这可能对肾小球疾病的发展很重要。
