LncRNA-p21调控Warburg效应促进肺动脉内皮细胞功能障碍的机制

Many apparently unrelated molecular abnormalities in PAH do have a common denominator; they either cause or promote the Warburg effect in pulmonary vascular cells; in turn, the signaling downstream from this mitochondrial suppression can also explain numerous molecular events previously not connected. Previous studies suggested that the Warburg effect could promote pulmonary vascular endothelial dysfunction but the mechanism remains unknown. We found that LncRNA-p21 was involved in enhancing the Warburg effect in hypoxia-induced PAH mouse; In addition, we also demonstrated that HMGB1 can promote endothelial dysfunction through the TLR4 pathway. Therefore, combining the latest research result that the Warburg effect promotes HMGB1 secretion, we speculated that LncRNA-p21 can promote endothelial dysfunction by regulating the HMGB1 secretion and downstream pathways through the Warburg effect, ultimately leading to PAH. In order to prove this point, the PAH mouse model induced by hypoxia will be utilized. First of all, the metabolomics approach will be applied to comprehensively and dynamically analysis the metabolic dysfunction in PAH, particularly the relevance of the Warburg effect. And the metabolic dysfunction will be further verified in plasma samples of a large number of PAH patients we have collected earlier. Then more importantly, it will be confirmed that the enhancement effect of LncRNA-p21 on the Warburg effect in hypoxia-induced PAH mouse model. Lastly, the mechanism how the Warburg effect promotes endothelial dysfunction through HMGB1 will be clarify. Thus, it would be able to illustrate the molecular mechanism how the Warburg effect promotes endothelial dysfunction in PAH. The present study will enrich the understanding of PAH, and provide new research ideas and potential therapeutic target for PAH.

Warburg效应是肺动脉高压(PAH)多种分子机制的共同通路，是治疗PAH重要的潜在靶点。Warburg效应可促进肺动脉内皮功能障碍但机制不清，我们前期发现LncRNA-p21促进缺氧诱导PAH小鼠Warburg效应，HMGB1可损伤肺血管内皮功能；结合Warburg效应促进HMGB1分泌的最新研究进展，因此推测LncRNA-p21可促进Warburg效应，继而通过HMGB1损伤内皮细胞功能导致PAH。本研究采用缺氧诱导小鼠PAH模型，结合代谢组学和分子生物学，首先构建PAH代谢网络以系统分析PAH-Warburg效应，接着重点探明LncRNA-p21促进Warburg效应的机制，然后证实Warburg效应通过HMGB1促进肺动脉内皮功能障碍，以此阐明LncRNA-p21调控Warburg效应影响内皮细胞功能的机制。本研究将丰富对PAH的认识，为PAH机制探讨提供新的研究线索及治疗靶点。

动态、系统的阐明PAH代谢变化是PAH诊治的重要突破口。本团队通过UPLC-MS/GC-MS 技术成功构建PAH代谢网络，发现包括Warburg效应在内的多种代谢通路的显著改变，并在此基础上筛选出具有较好临床诊断效能的潜在血浆代谢标志物。同时，在动物模型上探讨PAH代谢改变的分子调控机制。虽然没有在体内实验观察到LncRNA-p21敲低对低氧诱导肺动脉高压发生发展的保护作用，但我们意外发现低氧-PAH大鼠及MCT-PAH大鼠肠道产SCFA菌群及SCFA（丁酸）显著减少。丁酸是组蛋白去乙酰化酶的抑制剂，它积累在细胞核中能调控 HDAC 基因表达，起到抑制增殖、促进分化、诱导凋亡的作用。结合最新研究发现HDAC抑制剂（辛二酰苯胺异羟肟酸等）可显著减轻野百合碱诱导的肺高压大鼠肺动脉压力。因此我们将部分研究内容调整为丁酸对低氧-PAH小鼠肺动脉高压发生发展的影响及机制探讨。研究证实丁酸可以改善低氧诱导PAH大鼠的肺高压表型，并减少肺组织中HDAC5和PCNA的表达。此外，丁酸钠可抑制低氧或血小板源性生长因子（PDGF）诱导的肺动脉平滑肌细胞中HIF-1α、HMGB2、TLR4、TNF-α、HDAC5以及PCNA的表达量增加。本研究丰富了对PAH的认识，有望为PAH诊治提供新的靶点。