Silencing of STIM1 attenuates hypoxia-induced PASMCs proliferation via inhibition of the SOC/Ca2+/NFAT pathway

作者：Xianhua Hou, Jian Chen, Yongjun Luo, Fuyu Liu, Gang Xu, Yuqi Gao · 发表于：Respiratory Research · 年份：2013 · DOI：10.1186/1465-9921-14-2 · 被引用次数：58 · 研究领域：Ion Channels and Receptors、Pulmonary Hypertension Research and Treatments、Inflammation biomarkers and pathways

BACKGROUND: Stromal interaction molecule 1 (STIM1) is a newly discovered Ca2+ sensor on the endoplasmic reticulum which is an indispensable part in the activation of store-operated Ca2+ channels (SOC). Recent studies demonstrate that SOC of pulmonary smooth muscle cells (PASMCs) were upregulated by chronic hypoxia which contribute to the enhanced pulmonary vasoconstriction and vascular remodeling. However, the exact role of STIM1 in the development of chronic hypoxic pulmonary hypertension(HPH) remains unclear. METHODS: In this study we investigated the cellular distribution and expression of STIM1 by immunofluorescence, qRTPCR and Western blotting methods in Wistar rat distal intrapulmonary arteries under normal and chronic hypobaric hypoxic conditions. In vitro, Wistar rat PASMCs were isolated and cultured. PASMCs were transfected with siRNA targeting STIM1 gene by liposome. The expression of STIM1 protein was detected by Western blotting. [3H]-thymidine ([3H]-TdR) incorporation were performed to detect PASMCs proliferation. The cell cycle was analyzed by flow cytometry. The SOC-mediated Ca2+ influx was calculated by Ca2+ fluorescence imaging and the nuclear translocation of NFATc3 was determined by immunofluorescence and Western blot analysis of nuclear extracts. RESULTS: We found that during the development of HPH and the initiation of vascular remodeling, the mRNA and protein expression levels of STIM1 significantly increased in the distal intrapulmonary arteries. Modera...