泡沫细胞外泌体通过MALAT1和LincRNA-p21促进心肌细胞糖酵解加速心肌损伤的机制研究

Excessive glycolysis is a key feature of myocardial energy remodeling of heart failure and is detrimental to cardiac function. Previous studies have found that carotid plaque is harmful to cardiac function. Among patients with non-ischemic cardiomyopathy, cardiac function is worse in patients with atherosclerosis (AS) than those without. Furthermore, they also uncover that foam cells can up-regulate the glycolysis in cardiomyocyte through exosomes. The expression profile analysis showed that in exosomes, MALAT1 and LincRNA-p21, which could regulate glycolysis, were significantly up-regulated. Therefore, the project is intended to answer the following three key scientific questions: 1. In vivo, whether foam-derived exosome plays an important role in the regulation of myocardial glycolysis; 2. whether MALAT1 and LincRNA-p21 in these exosomes play key role in promoting glycolysis; 3. whether these LncRNAs in serum exosomes, which can regulate glycolysis, are related to the progress of clinical cardiac function. For this purpose, we intend to verify that in vivo foam cells exacerbate myocardial glycolysis by secreting exosomes which contain the LncRNAs mentioned above by labeling exosomes and specificly knocking down or overexpressing target LncRNAs as well as clarifying their mechanism. Besides,we also aim to figure out the correlation between the LncRNAs in serum exosomes and clinical progress of cardiomyopathy,which will provide a new way for the clinical diagnosis and treatment of heart failure.

过度糖酵解是心力衰竭心肌能量代谢改变关键特征并对心功能有害。前期研究发现，颈动脉斑块损害心功能；在非缺血性心肌病患者中，伴动脉粥样硬化较不伴者心功能恶化快；还发现泡沫细胞（FC）通过外泌体上调心肌细胞糖酵解。RNA-Seq发现外泌体中调控糖酵解的MALAT1和LincRNA-p21等明显上调。因此，本项目拟解决以下三个关键科学问题：1.在体内，FC源性外泌体是否在心肌糖酵解调节中起重要作用；2.这些外泌体是否通过包裹MALAT1和LincRNA-p21等促进糖酵解；3.血清外泌体这些调节糖酵解的LncRNAs是否与临床心功能进展相关。为此，本项目拟通过标记外泌体蛋白、巨噬细胞特异性基因敲低和过表达等方法确认FC在体内通过分泌外泌体并携带上述LncRNAs促进心肌糖酵解，同时阐明LcRNAs作用机制；还将探讨血清外泌体中这些LcRNAs与心肌病临床进展的相关性，为临床心力衰竭诊治提供新思路。

心力衰竭是各种心血管疾病发展到后期的共同阶段，是心肌损伤最集中和最严重的表现方式,而心力衰竭患者高发动脉粥样硬化性疾病。有研究提示，动脉粥样硬化斑块对心功能恶化起推动作用，且动脉粥样硬化性疾病的核心发病机制是泡沫细胞形成和发展，泡沫细胞在不引起缺血、不直接依赖循环系统炎性激活，以及代谢综合征组分的情况下，损害心肌功能的机制少有研究。本项目立足于泡沫细胞、外泌体以及其可能的非编码RNA途径与心肌损伤的关系，探讨了泡沫细胞外泌体参与心肌损伤的病理生理机制研究。该项目发现在泡沫细胞和动脉粥样硬化斑块形成过程中外泌体内MALAT1和lincRNA-p21含量升高，细胞源性外泌体促进心肌细胞糖酵解。本项目发现了外泌体抑制缺氧环境下的心肌细胞凋亡，还发现miR-144通过调控PTEN抑制心肌细胞凋亡，PTEN/AKT通路是外泌体抑制心肌细胞凋亡的重要作用途径。本项目进一步探讨发现，无论是体内还是体外实验，糖酵解的抑制均可以逆转心肌梗死后心肌成纤维细胞的激活。本项目为泡沫细胞外泌体参与心肌损伤的调控提功了基础实验证据的补充，为利用泡沫细胞外泌体及本研究相关通路来干预心肌损伤的可能提供了理论参考。