Jagged2/Notch3近距旁分泌作用调节肺动脉平滑肌细胞表型转换和增殖的机制

Notch3 activating in pulmonary arterial smooth muscle cells (SMC) has been reported to be an important "molecular and clinical phenotype" coupling mechanism in pulmonary vascular remodeling and pulmonary hypertension severity. However, it remains unknown how Notch3 is activated. Based on our previous research focusing on Notch signaling and interaction between vascular endothelial cells(EC) and SMC in rodent, we hypotheized that Jagged2 in EC is responsible for the activation of Notch3 in pulmonary artery hypension(PAH).During the progression of PAH, the elevation of Jagged2 could stimulate or inhibit EC to paracrine small molecule(s), which then induce Notch3 activation and phenotype shift of SMC towards pulmonary artery remodeling. By using rat PAH model induced with different methods as well as EC-SMC co-culture system,this study attempts to clarify the relationship between the expression level of Jagged2 in EC and the pulmonary hypertension severity as well as Notch3 activation in SMC.By screening the molecules produced by EC, which may influence the Notch3 activation and phenotype transition of SMC, This study is hopeful to clarify the Notch3 activation mechanisms in PAH and find novel targets for PAH treatment.

肺动脉平滑肌Notch3活化是反映肺血管重构和肺动脉高压严重程度重要的"分子-临床表型"偶联机制，但其活化机制不清。本项目在研究Notch信号调节血管内皮和平滑肌相互作用基础上，提出肺动脉高压时平滑肌Notch3活化与内皮Jagged2升高有关的假设：Jagged2通过促进/或抑制内皮分泌活性物质、进而激活肺动脉平滑肌Notch3信号并促进平滑肌表型转换和增殖。通过建立多种病因大鼠肺动脉高压模型和内皮-平滑肌共培养系统，观察肺动脉内皮Jagged2表达与肺动脉高压严重程度和平滑肌Notch3活化的相关性，明确内皮Jagged2对平滑肌Notch3活化的选择性调节及与平滑肌表型转换和增殖的关系，找出内皮Jagged2调节平滑肌表型转换和Notch3活化的分泌蛋白基因，阐明Jagged2/Notch3近距旁分泌作用调节肺动脉平滑肌细胞表型转换和增殖的机制，为寻找肺动脉高压治疗新靶点有重要意义。

肺动脉平滑肌Notch3活化是反映肺血管重构和肺动脉高压严重程度重要的“分子-临床表型”偶联机制，但其调控机制不清。本项目在研究Notch信号调节血管内皮和平滑肌相互作用基础上，提出肺动脉高压时平滑肌Notch3活化与内皮Jagged2升高有关的假设。分别通过野百合碱诱导肺动脉高压和主动脉弓缩窄建立左心疾病肺高压动物模型，发现不同病因导致肺血管重构时，肺组织Jagged2表达水平下调，Notch3表达水平上调，提示Jagged2/Notch3信号可能参与了肺血管重构的过程；通过microRNA筛选联合细胞共培养方法，我们发现左心疾病合并肺高压时，16个miRNAs 下调、2个miRNAs 上调2倍以上，其中Jagged2/Notch3信号和microRNA交互调节参与了肺动脉平滑肌增殖的过程，而miRNA206和miRNA149与肺高压的严重程度相关，其循环水平可能作为预测肺高压严重程度的循环标志物；通过基因组筛选肺动脉内皮细胞Jagged2调节的基因，发现通过小RNA干扰使肺动脉内皮Jagged2表达下调时，70个基因上调，415个基因下调，BMP信号可能在介导心肌肥厚的同时，也参与了肺血管重构的过程。该研究部分阐明Jagged2/Notch3信号调节肺动脉平滑肌细胞表型转换和增殖的机制，其中miRNA206和miRNA149可能作为预测肺高压的循环标志物，而BMP信号可能成为早期干预和逆转左心疾病患者肺高压的新靶点。