肺动脉内皮细胞和巨噬细胞间microRNA传递调节高密度脂蛋白表达影响肺动脉高压进展的作用及机制

Pulmonary hypertension (PAH) is a malignant pulmonary vascular disease. Our previous studies have found that the lower plasma high-density lipoprotein cholesterol (HDL) is associated with a worse prognosis in PAH patients; however, the intrinsic mechanism is still unclear. Previous studies proved that the HDL synthesis and efflux are regulated by membrane ATP binding cassette transporters (ABCA1/ABCG1). The reduced ABCA1/ABCG1 in macrophages due to exosomes released from hypoxia-treated pulmonary artery endothelial cells. The expression of microRNA-144-3p and microRNA-216b-5p which is the upstream regulators of ABCA1/ABCG1 in hypoxic pulmonary artery endothelial cells increased significantly .Based on these observations, we propose that the pulmonary artery endothelial cells may secrete the exosomes containing miRNA-144-3p and miRNA-216b-5p, which enter macrophages to regulate ABCA1/ABCG1 expression, thereby affecting HDL synthesis and participating in the pathogenesis of PAH. By establishing animal and cell models and employing genetic modification methods, this project aims to explore the detailed mechanism of microRNAs/ABC/HDL signaling pathway mediated by exosomes occurring between endothelial and macrophage, and ultimately, to provide a new idea for the treatment of PAH patients.

肺动脉高压（PAH）是肺血管内皮受损首发，伴有炎症细胞浸润的恶性肺血管疾病。申请人既往研究发现PAH患者血浆高密度脂蛋白胆固醇（HDL）水平越低预后越差，但具体机制不明。结合研究提示HDL合成受细胞膜上三磷酸腺苷结合盒转运体ABCA1/ABCG1调控，申请人进行预实验发现缺氧处理的肺动脉内皮细胞释放的外泌体可显著降低巨噬细胞ABCA1/ABCG1的表达，且缺氧组内皮细胞ABCA1/ABCG1上游外泌体miR-144-3p和miR-216b-5p表达显著增加。基于此，申请人推测肺动脉内皮细胞外泌体miR-144-3p和miR-216b-5p进入巨噬细胞调控ABCA1/ABCG1表达，从而影响HDL合成，参与PAH发病过程。为此本研究拟采用基因修饰等技术经系列实验探讨外泌体miRNAs在内皮细胞和巨噬细胞间传递调控HDL合成参与肺血管重构过程，为PAH治疗提供新思路。

肺动脉高压（PAH）是肺血管内皮受损首发，伴有炎症细胞浸润的恶性血管疾病。申请人既往研究发现PAH患者血浆高密度脂蛋白胆固醇（HDL）水平越低预后越差，但具体机制不明。我们收集了407例正常人和361IPAH患者的血浆样本，通过进行脂质水平检测，发现IPAH患者中的TC，HDL-C，ApoA-I水平明显下降，其中HDL-C，ApoA-I的水平下降最为显著；14例PVOD患者和41例正常人相比，PVOD患者中TG，HDL-C，LDL，ApoA-I，ApoB，Apo E的水平明显下降，其中ApoA-I和HDL-C的水平下降较为显著。基于缺氧组内皮细胞外泌体与对照组相比miR-144-3p和miR-216b-5p表达显著增加的结果，我们进行了12例IPAH患者发现队列和46例验证队列的血浆外泌体MicroRNA对患者预后的分析。结果发现，死亡患者miR-596表达显著上调，其水平与平均右心房压、肺血管阻力呈正相关，与心脏指数呈负相关，外泌体miR-596水平越高，预后越好。因此，血浆外泌体miR-569可作为预测IPAH患者预后的新生物标志物。随后，我们检测70名IPAH患者和30名健康对照组的脂质代谢组学分析。结果发现，IPAH组血浆FFA水平显著高于对照组。其中ln-FFA（14:0）每增加一个单位，IPAH的发病风险比增加超过24倍。以ln-FFA（14:0）水平6.508作为界值，可以将IPAH患者与对照组区分开来，敏感性为85.5%，特异性为90.0%。这提示FFA也是筛选IPAH发病风险增加的重要标记物。最后，体外实验验证巨噬细胞和内皮细胞间HDL和FFA的作用，进一步证实了IPAH是一种能量消耗疾病，需要调整脂质代谢来辅助治疗患者。

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