环状RNA在肺动脉高压中的作用及机制研究

PAH (pulmonary arterial hypertension) is a malignant pulmonary disease leading to sudden death; however, the underlying mechanisms are still elusive. In a recent study, we screened a number of circular RNA (circRNA) in the lung tissue of hypoxic PAH patients. We found circRNA_100526 to be upregulated and two circRNA (circ_0068281 and circRNA_103054) to be down-regulated significantly. Bioinformatics analysis indicates their interaction with PAH associated miRNA and mRNA. To determine their role in the etiology of PAH, we design the present study to investigate how these dysregulated circRNA affect pulmonary arterial vessel constriction and remodeling by targeting miRNA and which intracellular signaling mechanism are important. Using gene knockout /knockdown mice and cells, we design series of loss/gain of function study. PA rings, Western blot, quantitative real-time PCR, Fluorescence in situ hybridization are designed to investigate the role of circRNA in hypoxic PAH.

肺动脉高压是一种极度恶性疾病，机制未明。我们的研究发现，肺动脉高压患者肺组织中环状RNA(circRNA)表达谱发生显著变化，其中circRNA_100526上调明显，circ_0068281，circRNA_103054下调明显。生物信息学提示上述circRNA与调节肺动脉高压相关的重要miRNA以及下游靶基因存在相互作用位点。据此，本申请提出研究假设：缺氧通过上/下调circRNA，竞争性结合miRNA，调控与肺血管收缩、重构相关的靶基因，进而引发肺动脉高压。拟以circRNA敲除/干扰/过表达的小鼠/细胞模型为基础，采用芯片分析、组织灌流、qPCR、荧光原位杂交、共转染、免疫组化等技术揭示circRNA在缺氧性肺动脉收缩和重构中的作用，探索circRNA调控的网络及分子机制，在基因水平揭示肺动脉高压的发病机理，为临床提供新的诊断标志物和潜在的治疗靶点。

肺动脉高压是一种极度恶性疾病，机制未明。本项目研究基于临床肺动脉高压患者全血为基础，证实病人全血中hsa_circNFXL1_009表达显著下调, hsa_circWDR37_016的表达显著上调。功能研究表明在平滑肌细胞中，缺氧可上/下调hsa_circWDR37_016/hsa_circNFXL1_009，导致PASMCs过度增殖，凋亡抵抗及迁移，hPASMCs增殖和细胞周期异常，引起肺动脉高压发展的肺血管重塑过程。机制研究表明，hsa_circNFXL1_009表达的降低可能通过海绵吸附作用调节miR-29b-2-5p/KCNB1轴，引起导致细胞内K+通道活性的降低。因此,hsa_circNFXL1_009和 hsa_circWDR37_016可能是肺动脉高压患者诊断的重要标志物和调节因子，可能是抑制PAH发展的一种潜在分子治疗靶点。此外首次证实miR-223在氧化应激下对KATP通道的重要的调节作用。在氧化应激状态，miR-223表达水平急剧增加，可作用在Kir6.1 mRNA的3 ' UTR上，从而抑制KATP通道活性，进而损害KATP通道依赖的血管张力调节，保持miR-223在糖尿病中表达的稳定可能是糖尿病血管功能障碍的治疗和预防的重要策略。再次，在甲状腺癌（PTC）患者中发现7个分化显著的环状RNA，表明环状RNA失调在PTC发病机制中发挥了关键作用。hsa_circ_IPCEF1作为下调的circRNA，有可能成为PTC潜在的生物标志物。hsa_circ_IPCEF1/hsa‑miR‑3619‑5p轴可能参与了PTC的发病机制，为今后PTC的诊断和治疗提供了新的理论依据。