The Role of Angiotensin II in Glomerular Volume Dynamics and Podocyte Calcium Handling.
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 Ca2+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 Ca2+influx in the podocytes is precluded by blocking either AT1or AT2receptors (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 La3+, 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.
Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA.
Daria V
DV
Ilatovskaya
Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA.
Oleg
0000-0002-3680-5527
O
Palygin
Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA.
Vladislav
V
Levchenko
Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA.
Bradley T
BT
Endres
Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, 53226, USA. staruschenko@mcw.edu.
Alexander
0000-0002-5190-8356
A
Staruschenko
D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D021621:Imaging, Three-Dimensional; D007678:Kidney Glomerulus / Q000187:drug effects* / Q000502:physiology; D018613:Microscopy, Confocal; D018408:Patch-Clamp Techniques; D050199:Podocytes / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats; D000074287:TRPC6 Cation Channel / Q000378:metabolism*; D014662:Vasoconstrictor Agents / Q000378:metabolism*
D000074287:TRPC6 Cation Channel; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; D002118:Calcium