Pressure-induced and store-operated cation influx in vascular smooth muscle cells is independent of TRPC1

Item Type:	Article
Title:	Pressure-induced and store-operated cation influx in vascular smooth muscle cells is independent of TRPC1
Creators Name:	Dietrich, A. and Kalwa, H. and Storch, U. and Mederos Y Schnitzler, M. and Salanova, B. and Pinkenburg, O. and Dubrovska, G. and Essin, K. and Gollasch, M. and Birnbaumer, L. and Gudermann, T.
Abstract:	Among the classical transient receptor potential (TRPC) subfamily, TRPC1 is described as a mechanosensitive and store-operated channel proposed to be activated by hypoosmotic cell swelling and positive pipette pressure as well as regulated by the filling status of intracellular Ca(2+) stores. However, evidence for a physiological role of TRPC1 may most compellingly be obtained by the analysis of a TRPC1-deficient mouse model. Therefore, we have developed and analyzed TRPC1(-/-) mice. Pressure-induced constriction of cerebral arteries was not impaired in TRPC1(-/-) mice. Smooth muscle cells from cerebral arteries activated by hypoosmotic swelling and positive pipette pressure showed no significant differences in cation currents compared to wild-type cells. Moreover, smooth muscle cells of TRPC1(-/-) mice isolated from thoracic aortas and cerebral arteries showed no change in store-operated cation influx induced by thapsigargin, inositol-1,4,5 trisphosphate, and cyclopiazonic acid compared to cells from wild-type mice. In contrast to these results, small interference RNAs decreasing the expression of stromal interaction molecule 1 (STIM1) inhibited thapsigargin-induced store-operated cation influx, demonstrating that STIM1 and TRPC1 are mutually independent. These findings also imply that, as opposed to current concepts, TRPC1 is not an obligatory component of store-operated and stretch-activated ion channel complexes in vascular smooth muscle cells.
Keywords:	TRPC1-Deficient Mice, Classical Transient Receptor Channel 1, Store-Operated Cation Influx, Pressure-Induced Cation Influx, Bayliss Effect, STIM1, Thapsigargin, Inositol-1,4,5 Trisphosphate, Animals, Mice
Source:	Pfluegers Archiv European Journal of Physiology
ISSN:	0031-6768
Publisher:	Springer
Volume:	455
Number:	3
Page Range:	465-477
Date:	December 2007
Official Publication:	https://doi.org/10.1007/s00424-007-0314-3
PubMed:	View item in PubMed

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