lncRNA-AK048451增强Smad3促心肌纤维化的机制研究

心肌纤维化是导致心脏重塑难以逆转的最主要病理改变之一。我们在蛋白水平证实AngII/TGF-β1激活，上调Smad2/3及下调Smad7，促进心肌胶原合成，结果发表在“Circ Res”上。今年我们报道MicroRNA-21直接与Smad7结合并引起其下调，进而增强纤维化，提示RNA参与Smads的调节。本课题前期研究发现lncRNA- AK048451(lnc-AK)在大鼠及人的纤维化心肌中显著升高。下调lnc-AK后，心梗大鼠心肌纤维化明显改善。LncRNA靶点预测IncAK和Smad3有结合位点。我们假设心肌纤维化过程，上调的Inc-AK增加Smad3进而促进纤维化。为证实以上假设，本项目使用基因芯片、腺病毒转染、ChIP、RNA-pull down、FISH、qRT-PCR、Western-blot等方法，旨在获得Inc-AK与Smad3的调控机制，为心肌纤维化的防治奠定理论基础。

Myocardial fibrosis is one of the most important leading pathological injury of myocardial remodeling. Our preliminary study did some researches on the effects of AngII/TGF-β1/Smads signal on myocardial fibrosis at the protein level, which was published in "Circ Res". In this year, we found that MicroRNA-21 increased significantly in myocardial fibrosis. MicroRNA-21 down-regulated Smad7 through direct combination and enhanced the increase of collagen caused by TGF-β1, which indicated that RNA was involved in the regulation of Smads. Next, we found that lncRNA-AK048451(lnc-AK) was significantly elevated in the heart tissues of myocardial infarction rat model and the patients with coronary heart disease. lnc-AK is highly conserved between human and rat. The target prediction of LncRNA found Smad3 has mutual binding site with lnc-AK. After down-expressed lnc-AK, it was found that myocardial fibrosis was ameliorated. However, how did lnc-AK mediate myocardial fibrosis? There has no relevant report at present. We assume that lnc-AK enhances the promotion of myocardial fibrosis by up-regulation of Smad3. To confirm the assumption, our project will use the gene chip, adenovirus transfection, ChIP, RNA-pull down, FISH, qRT-PCR, western-blot, etc to obtain direct relation between Smad3 and lnc-AK and find the cellular and molecular mechanism of its promoting myocardial fibrosis, which may help to lay a theoretical foundation for the prevention and treatment of myocardial fibrosis.