TY - JOUR AU - ZHANG Ya-juan AU - ZHENG Hua-qing AU - CHEN Bao-yi AU - SUN Lu AU - MA Ming-ming AU - WANG Guan-lei AU - GUAN Yong-yuan PY - 2017 TI - WNK1 is required for proliferation induced by hypotonic challenge in rat vascular smooth muscle cells JF - Acta Pharmacologica Sinica; Vol 39, No 1 (January 2018): Acta Pharmacologica Sinica Y2 - 2017 KW - N2 - Abstract Hypotonic challenge evoked vascular cell proliferation through activation of volume-regulated Cl – channel (VRCC), leading to a decrease in the intracellular Cl – concentration ([Cl – ] i ). We hypothesize that the decrease in [Cl – ] i may activate one or several Cl – -sensitive kinases, resulting in a subsequent signaling cascade. In this study we demonstrated that WNK1, a Cl – -sensitive kinase, was involved in VRCCinduced proliferative signaling pathway in A10 vascular smooth muscle cells in vitro . A10 cells were exposed to a hypotonic challenge (225 mosmol·kg -1 ·H 2 0), which caused significantly increase in WNK1 phosphorylation without altering WNK1 protein expression. WNK1 overexpression significantly increased hypotonic-induced A10 cell proliferation, whereas silencing of WNK1 caused an opposite action. WNK1 mutation did not affect hypotonic-induced WNK1 phosphorylation and cell proliferation. Silencing of WNK1 caused cell cycle arrest at G 0 /G 1 phase and prevented transition from G 1 to S phase, whereas the WNK1 overexpression accelerated cell cycle transition from G 1 to S phase. Silencing of WNK1 significantly inhibited cyclin D1/cyclin E1 expression and increased p27 KIP /p21 CIP expression. WNK1 overexpression significantly increased cyclin D1/cyclin E1 expression and reduced p27 KIP /p21 CIP expression. In addition, WNK1 knockdown or overexpression significantly attenuated or increased the hypotonic-induced phosphorylation of Akt and PI3K respectively. In conclusion, the reduction in [Cl – ] i caused by hypotonic challenge-induced VRCC opening evokes WNK1 phosphorylation in A10 VSMCs, which mediates cell cycle transition from G 0 /G 1 to S phase and proliferation through the PI3K-Akt signaling pathway. UR - http://www.chinaphar.com/article/view/9702