钙敏感受体介导的中性粒细胞外泌体LncRNA ENSRNOT00000039868在急性心肌梗死中的作用和机制研究

中性粒细胞(PMN)参与急性心肌梗死(AMI)的发生发展，机制尚不明确，本课题组发现淋巴细胞钙敏感受体(CaSR)也参与AMI的发生，而PMN的CaSR是否参与尚无报道。我们预实验发现PMN的CaSR活化促进缺氧复氧心肌细胞的凋亡，同时使PMN外泌体中LncRNAENSRNOT00000039868的含量增加；另检测到AMI大鼠外周血PMN的CaSR表达降低。由此推测“中性粒细胞CaSR通过调节外泌体LncRNA影响AMI的发生发展”。为证实该假说，本课题拟采用基因转染等技术验证此LncRNA的靶基因及其相关信号传导通路；利用大鼠心肌缺血再灌注模型，明确PMN外泌体及此LncRNA的作用；将缺氧复氧心肌细胞与沉默或过表达CaSR和此LncRNA的中性粒细胞分泌的外泌体共培养，检测通路蛋白及心肌细胞功能指标，从而阐明AMI与PMN中CaSR及外泌体LncRNA的关系，寻找AMI防治新靶点。

Neutrophil (PMN) is involved in the occurrence and development of acute myocardial infarction (AMI), however, the mechanism remains unclear. Our team has discovered that calcium-sensing receptor (CaSR) in the peripheral blood lymphocytes were involved in AMI, but whether the CaSR in PMN to participate in is not reported. In our pre-experiments, we have found that the activation CaSR in peripheral blood PMN promoted hypoxia/reoxygenation cardiomyocytes apoptosis, at the same time, the expression of LncRNA ENSRNOT00000039868 in exosomes from neutrophils increased; in addition, we detected that the expression of CaSR in peripheral blood PMNs decreased. So, we hypothesized that "CaSR in neutrophils may be involved in the development and progression of AMI by modulating LncRNA in exosomes". In order to confirm the hypothesis, we will use techniques such as gene transfection to verify the target gene of this LncRNA and related signaling transduction pathway; to confirm the role of PMN-derived exosomes and this LncRNA in AMI by remodeling rat ischemia-reperfusion model; to observe the pathway proteins and function indicators of cardiomyocytes by co-culturing neonatal rat cardiomyocytes under hypoxia-reoxygenation condition with exosomes secreted by PMN silenced or over-expressed with CaSR or this LncRNA. It will clarify the relationship between AMI and CaSR in PMN and LncRNA in exosomes, and find a new target for the prevention and treatment of AMI.