Nicotine-Induced Airway Smooth Muscle Cell Proliferation Involves TRPC6-Dependent Calcium Influx Via α7 nAChR
Nicotine-Induced Airway Smooth Muscle Cell Proliferation Involves TRPC6-Dependent Calcium Influx Via α7 nAChR
复制标题
尼古丁诱导的气道平滑肌细胞增殖涉及 TRPC6 依赖性钙离子通过 α 7 nAChR 的流入
DOI：
10.1159/000481651
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发表时间：
2017-01-01
影响因子：
--
通讯作者：
Ran, Pixin
中科院分区：
文献类型：
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作者：
Hong, Wei;Peng, Gongyong;Ran, Pixin
背景/目标：人支气管平滑肌细胞（HBSMCs）的增殖是慢性阻塞性肺疾病（COPD）气道重塑的关键病理生理学组成部分，药物治疗有限，近几十年来仅实现了生存率的轻微改善。香烟烟雾是COPD的一个公认的危险因素，然而，香烟烟雾诱导的COPD的发病机制仍不完全清楚。本研究旨在探讨尼古丁影响HBSMC增殖的机制。方法：CCK-8法测定细胞活力。通过细胞计数和EdU免疫染色测量增殖。荧光钙成像检测细胞内钙离子浓度（[Ca 2 +]i）。结果如下：结果表明，尼古丁促进HBSMC增殖，并伴随着细胞内钙库操纵的钙内流（SOCE）、受体操纵的钙内流（ROCE）和基础[Ca ~（2+）]i的升高。此外，我们还证实了经典瞬时受体电位蛋白6（TRPC 6）和α7烟碱乙酰胆碱受体（α7 nAChR）参与尼古丁诱导的细胞增殖上调。此外，我们证实PI 3 K/Akt信号通路的激活在尼古丁增强的HBSMCs增殖和钙内流中起关键作用。抑制α7 nAChR显著降低Akt磷酸化水平，LY 294002抑制TRPC 6蛋白表达水平。结论：在此，这些数据提供了令人信服的证据，即通过α7 nAChR-PI 3 K/Akt-TRPC 6信号通路的钙进入在气道平滑肌细胞增殖的生理调节中起重要作用，代表了增强气道重塑的重要靶点。
Background/Aims: The proliferation of human bronchial smooth muscle cells (HBSMCs) is a key pathophysiological component of airway remodeling in chronic obstructive pulmonary disease (COPD) for which pharmacotherapy is limited, and only slight improvements in survival have been achieved in recent decades. Cigarette smoke is a well-recognized risk factor for COPD; however, the pathogenesis of cigarette smoke-induced COPD remains incompletely understood. This study aimed to investigate the mechanisms by which nicotine affects HBSMC proliferation. Methods: Cell viability was assessed with a CCK-8 assay. Proliferation was measured by cell counting and EdU immunostaining. Fluorescence calcium imaging was performed to measure intracellular Ca2+ concentration ([Ca2+]i). Results: The results showed that nicotine promotes HBSMC proliferation, which is accompanied by elevated store-operated calcium entry (SOCE), receptor-operated calcium entry (ROCE) and basal [Ca2+]i in HBSMCs. Moreover, we also confirmed that canonical transient receptor potential protein 6 (TRPC6) and α7 nicotinic acetylcholine receptor (α7 nAChR) are involved in nicotine-induced upregulation of cell proliferation. Furthermore, we verified that activation of the PI3K/Akt signaling pathway plays a pivotal role in nicotine-enhanced proliferation and calcium influx in HBSMCs. Inhibition of α7 nAChR significantly decreased Akt phosphorylation levels, and LY294002 inhibited the protein expression levels of TRPC6. Conclusion: Herein, these data provide compelling evidence that calcium entry via the α7 nAChR-PI3K/Akt-TRPC6 signaling pathway plays an important role in the physiological regulation of airway smooth muscle cell proliferation, representing an important target for augmenting airway remodeling.