Mir-140b-3p调控CD38/NAADP信号通路参与哮喘气道平滑肌细胞自噬、凋亡的机制研究

Calcium signal regulate proliferation, apoptosis of airway smooth muscle cells (ASMCs) in airway remodeling in asthma. Autophagy and apoptosis play a different role in the disease process by mutual influence. it is unclear whether autophagy and apoptosis contribute to the proliferation of ASMCs in asthma. CD38 can catalyzed substrate to produce second messenger molecules nicotinic acid adenine dinucleotide phosphate (NAADP), NAADP regulate the release of intracellular Ca2+ involved in autophagy. CD38 is widely expressed in ASMCs, it is unclear whether CD38 regulating NAADP/Ca2+ signal pathway is involved in autophagy and apoptosis in asthmatic airway smooth muscle cells. CD38 is the target gene of miR-140-3p, miR-140-3p regulate the expression of CD38 in airway smooth muscle cells, we hypothesis that Mir-140b-3p regulating CD38/NAADP signal pathway is involved in autophagy and apoptosis in the asthmatic ASMCs. In this study, we will isolate rat ASMCs, Chronic rat asthmatic model will be established, autophagy inducer or autophagy specific inhibitor will be used. then we silence or enhance the expression of the key signaling molecules in ASMCs or rat asthmatic model, autophagy and apoptosis will be detect by transmission electron microscopy or molecular biology technology. We now sought to elucidate that Mir-140b-3p regulating autophagy and apoptosis of ASMCs contributes to airway remodeling of asthma through activated CD38/NAADP signal pathway. It is a completely new interpretation in pathogenesis of asthmatic airway remodeling.

钙信号通过调控气道平滑肌细胞(ASMCs)增殖、凋亡参与哮喘气道重塑。自噬与凋亡在疾病过程中相互影响发生作用，它们在哮喘ASMCs增殖中起何作用？CD38催化底物生成的第二信使分子烟碱酸腺嘌呤二核苷酸磷酸（NAADP）调节细胞内Ca2+释放影响细胞自噬，ASMCs膜广泛表达的CD38是否通过NAADP调控的Ca2+信号参与ASMCs自噬、凋亡？miR-140-3p是否通过调控靶基因CD38的表达，影响NAADP/Ca++信号轴诱导的ASMCs自噬、凋亡？本项目拟通过关键信号分子沉默或增强、自噬诱导剂或抑制剂干预体外培养的ASMCs及慢性哮喘大鼠模型，应用透射电镜、分子生物学技术等检测细胞自噬、凋亡的发生，探讨细胞自噬、凋亡与CD38/NAADP信号通路的关系、Mir-140b-3p调控CD38/NAADP信号通路参与哮喘ASMCs自噬、凋亡的机制，对哮喘气道重塑的发病机制进行了全新的诠释。

研究证实难治性哮喘的病人中存在气道平滑肌自噬，同时TNF-α与气道平滑肌自噬相关，但其具体机制尚不清楚。现我们证实了TNF-α可以通过CD38/NAADP 信号通路参与气道平滑肌自噬调节。我们的数据表明TNF-α可以增加气道平滑肌自噬小体的数目，当我们用CD38/NAADP 信号通路特异性抑制剂尼可酰胺以及PPADS作用于气道平滑肌后，自噬潮减弱。但是TNF-α可以拮抗这减弱作用。机制研究证实TNF-α可以促进CD38的表达，拮抗尼可酰胺从而促进自噬小体向自噬溶酶体转换。总之，本项研究不仅证实了TNF-α/CD38/NAADP信号轴在气道平滑肌的作用，同时为TNFα在临床治疗哮喘提供基础实验依据。