长非编码RNA-VELRP促进肺动脉平滑肌细胞增殖和肺血管重构的功能及机制

Pulmonary arterial hypertension (PAH), a complex vascular disease with a dreadful survival rate, is characterized by abnormal proliferation of pulmonary arterial smooth muscle cell (PASMC) and progressive structural remodeling of pulmonary arteries. Platelet-derived growth factor (PDGF) is a strong mitogen for PASMC. Inhibition of the PDGF signaling pathway becomes a potential target for the treatment of PAH. Long non-coding RNAs are a novel regulator with multiple biological functions; however, little is known about their role and mechanism in the development of PAH. In our preliminary study, we identified that a vessel enriched lncRNA VELRP was significantly induced by PDGF-BB treatment. Functionally, we observed a significant decrease of PASMC proliferation due to the silencing of VELRP by shRNA. Based on the results above, we propose that PDGF-BB-induced VELRP might contribute to the development of PAH. In this proposal, we will study expression regulation of VELRP induced by PDGF-BB and investigate its biological function and possible mechanism related to PASMC proliferation. Using hypoxia or MCT induced PAH rat model and VERLP knockout PAH rat models, the impact of VELRP on pulmonary vascular remodeling and PAH development will be investigated. Finally, the clinical relationship between VELRP level and PAH disease will be evaluated. The main purpose of this project is to elucidate a new molecular mechanism of PDGF-BB-induced PAH involved in lncRNA. The results will also provide a new clue to develop drug for PAH based on inhibition of PDGF pathway.

肺动脉高压(PAH)发病机制复杂，死亡率高，肺动脉平滑肌细胞(PASMC)异常增殖引起血管重构是其重要的病理学基础。PDGF是PASMC强有力的有丝分裂原，阻断PDGF通路已成为治疗PAH的有效靶点。lncRNA是一类新发现具有多种功能的调节者，但目前与PAH相关的lncRNA了解很少。前期研究发现了一个富集在血管且在PDGF-BB刺激后显著上调的lncRNA VELRP，干扰其表达可显著抑制PASMC增殖。推测，PDGF-BB通过上调VELRP参与诱发PAH。本项目拟从分子水平揭示VELRP的表达、调控、功能和作用机制;以低氧或MCT诱导的PAH大鼠及VELRP基因敲除PAH大鼠为模型，探讨VELRP在血管重构和PAH发生中的作用;明确VELRP表达与PAH发生在临床上的相关性。研究结果将从lncRNA角度阐述PDGF诱发PAH的新机制，也为开发基于抑制PDGF通路的治疗药物提供新思路。

肺动脉高压(PAH)发病机制复杂，死亡率高，肺动脉平滑肌细胞(PASMC)异常增殖引起血管重构是其重要的病理学基础。PDGF是PASMC强有力的有丝分裂原，阻断PDGF通路已成为治疗PAH的有效靶点。lncRNA是一类新发现具有多种功能的调节者，但目前与PAH相关的lncRNA了解很少。本项目通过组织表达谱筛选，鉴定到了一个血管特异性高表达的lncRNA – VELRP，在低氧或野百合碱（MCT）诱导的PAH大鼠肺动脉和肺组织中均发现VELRP表达显著上调，预示其可能在肺动脉重构和PAH的发生中发挥作用；通过cDNA末端扩增技术（RACE）阐明了VELRP的基因结构，并以此为依据通过CRISPR技术构建了VELRP的敲除大鼠，发现VELRP敲除可以一定程度缓和MCT或低氧+Sugen 5416诱导的PAH症状，有效抑制血管中层变厚，提示VELRP有可能调控肺动脉中层PASMC功能；敲低PASMC中VELRP的表达，通过RNA二代测序进行转录组分析，对差异基因进行生物信息学分析，结果提示VELRP可能调控PASMC增殖，功能实验结果证实VELRP调控PASMC细胞增殖及表型分子表达；接着，项目深入探讨VELRP调控PASMC增殖和肺动脉重构的作用机制，研究发现，VELRP可通过结合WDR5，调控pttg1和spc25等细胞周期相关基因启动子位置的组蛋白H3的第4位赖氨酸甲基化，激活相关基因的表达促进细胞周期进程；在VELRP的表达调控部分，研究发现生长因子PDGF-BB和FGF2可通过JNK/p53通路上调VELRP的表达；最后，项目在PAH患者来源的PASMC中检测到VELRP的显著上调，提供了VELRP和PAH发生在临床上的相关性证据。总而言之，项目从非编码RNA角度解析了肺血管重构和PAH发生的新机理，为开发抗PAH药物提供了新线索。