miR-23b与TGF-β1 /TGFβRⅡ/ Smad3信号通路交互作用调控哮喘气道重塑的研究

We have demonstrated that TGF-β1/Smad3 signalling pathway plays an important role in airway remodeling in asthma. miR-23b, a multi-functional microRNA(miRNA), is believed to participate in a wide range of signalling pathways. Since our previous study has firstly proven that miR-23b is low expressed in primary airway smooth muscle cells(ASMCs) isolated from asthmatic mice by performing real-time PCR, the present research is designed to explore the potential mechanism of this miR-23b downregulation with cell cultures, pharmacologic experiments and molecular biological techniques. Then we seek to investigate the effects of miR-23b overexpression/inhibition on the proliferation and apoptosis of ASMCs as well as TGFβRⅡ/ Smad3 expression after TGF-β1 stimulation. Dual-Luciferase Reporter Assay System will be applied to identify whether TGFβRⅡ and Smad3 are the target genes of miR-23b. Meanwhile, we intend to study the effects of miR-23b overexpression/inhibition on airway remodeling and TGF-β1 /TGFβRⅡ/Smad3 signalling pathway in asthmatic mice. By this research we expect to illustrate the role of miR-23b in airway remodeling and provide evidence for miR-23b as a potential therapeutic target in asthma.

我们已经证实TGF-β1/Smad3信号通路在支气管哮喘气道重塑中起重要作用。miR-23b是一个多功能微小RNA(miRNA)，参与调节多种信号通路。应用Real-time PCR技术，我们首次发现气道重塑的哮喘小鼠原代气道平滑肌细胞（ASMCs）miR-23b显著下调。本项目拟以细胞培养、药理学实验及分子生物学技术探讨哮喘小鼠ASMCs miR-23b下调的可能机制；观察TGF-β1作用下哮喘小鼠ASMCs增殖、凋亡及TGFβRⅡ和Smad3蛋白的表达是否受miR-23b过表达/抑制的调控；以双荧光素酶报告基因验证miR-23b是否靶向调控TGFβRⅡ和Smad3；同时动物模型观察miR-23b过表达/抑制，对哮喘小鼠气道重塑及TGF-β1 /TGFβRⅡ/Smad3信号通路的作用。旨在获得miR-23b参与调控哮喘气道重塑的证据，为确立miR-23b作为哮喘治疗的新靶标提供科学依据。

我们已经证实TGF-β1/Smad3 信号通路在支气管哮喘气道重塑中起重要作用。miR-23b 是一个多功能微小RNA(miRNA)，参与调节多种信号通路。应用Real-time PCR 技术，我们首次发现气道重塑的哮喘小鼠原代气道平滑肌细胞（ASMCs）miR-23b 显著下调。本项目通过细胞培养、药理学实验及分子生物学技术探讨哮喘小鼠ASMCs miR-23b 下调的可能机制。我们已经证实，与正常小鼠对照组相比，在哮喘小鼠组中，通过激光捕获显微切割技术得到的气道平滑肌细胞中TGF -β1和miR -23b mRNA表达水平升高。与此同时，在细胞实验中发现TGF - β1诱导的ASMCs中miR -23b mRNA表达增加。miR - 23b上调明显抑制TGF - β1诱导的ASMCs增殖，促进细胞凋亡。miR - 23b在ASMCs中负调控Smad3的表达。双荧光素酶报告系统显示Smad3是miR - 23b的直接靶点。我们的研究表明，miR- 23b通过靶向调控Smad3抑制了ASMCs的增殖。我们的发现获得了miR-23b 参与调控哮喘气道重塑的证据，为确立miR-23b 作为哮喘治疗的新靶标提供科学依据。