microRNA-630/RBFOX2介导的雌激素受体在肺动脉高压发病中的作用及机制研究

Pulmonary arterial hypertension (PAH) is a malignant pulmonary vascular disease with an unclear pathogenesis. Clinical studies have demonstrated a clearly female preponderance, especially in young patient population. The preliminary results from our study group revealed that estradiol (E2 ) level in female patients was significantly lower than age-matched female controls. Furthermore, the E2 level in MCT induced PAH rats also significantly lower than the non-PAH rats. Those findings strongly suggested the decrease of E2 level may be involved in the pathogenesis of PAH. Additionally, E2 could up-regulate the expression of eNOS in lung tissue of PAH rats. However, the mRNA expression was not changed; indicated miRNA may be involved in the regulation of E2 expression. Recently, we have confirmed the miR-630 was up-regulated in lung tissue of PAH patients compared with non-PAH patients. The target gene RBFOX2 of miR-630 screened from TARGETSCAN could regulate estrogen receptor transcription. Therefore, we hypothesized that miR-630/RBFOX2 could regulate estrogen receptor level to be involved in the progression of PAH. The current program will investigate that if and how the miR-630/RBFOX2 could influence the progression of MCT induced PAH rats through regulating the estrogen receptor, which will provide a new idea for further understanding the mechanism of sex hormones in PAH.

肺动脉高压（PAH）是危害严重的恶性肺血管疾病，女性多发，发病机制尚不明确。申请人所在中心已证实女性PAH患者血浆雌二醇（E2）水平显著低于对照，野百合碱诱导雌性PAH大鼠的血浆E2水平也明显降低，而给予E2显著缓解肺血管及右心重构，上述发现均提示E2减少和PAH发病有关。此外，该研究显示，E2上调PAH肺组织一氧化氮合酶蛋白的表达，但不影响其mRNA表达，说明E2可能通过miRNA来调控其表达。故我中心已检测特发性PAH患者与非PAH患者肺动脉miRNA差异表达谱，证实miR-630在患者肺组织表达上调。而miR-630靶基因RBFOX2能调节雌激素受体（ER）α转录水平。因此，我们推测miR-630/RBFOX2通过调节ER水平来参与PAH发病。本项目拟在整体和细胞水平通过实验证实miR-630/RBFOX2是通过ER调控野百合碱所致PAH发展的作用及机制，为PAH药物治疗探索新靶点。

肺动脉高压（PAH）是危害严重的恶性心肺血管疾病。既往研究显示，性激素水平在肺动脉高压发病和疾病进展过程中均有重要影响，但现有证据仍有矛盾之处，机制也不明确。同时，也有研究证实microRNA在肺动脉高压患者发病中有重要作用，有潜力成为肺动脉高压疾病的重要生物标记物。但截止目前，关于肺动脉高压动物模型和患者中和性激素相关的microRNA研究却仍然欠缺。本项目建立了可靠野百合碱大鼠肺动脉高压模型，并可行准确血流动力学测定。通过本动物模型观察到雌二醇干预可显著改善肺动脉高压大鼠的临床表型，观察到包括miR-223等5个microRNA表达水平变化。而经过雌二醇治疗后，这5个microRNA在肺动脉平滑肌细胞中的表达又发生了显著逆转，提示雌二醇很可能通过这些microRNA发挥保护肺血管重构作用。通过生物信息网站，对miR-223下游靶分子预测，选择和肺动脉高压相关的IGF-1R进行验证。后续大鼠动物实验发现，雌二醇可以通过调节miR-223等多个microRNA表达来调节靶蛋白IGF-1和IGF-1R表达，从而影响下游信号通路蛋白HIF-1α 和 PARP-1 的表达，抑制细胞增殖。此外，我们还观察到肺动脉高压大鼠右心室miR-21-5p表达增高，miR-223-3p和miR-466-b表达显著降低。而PDGF可以诱导右心室心肌细胞过度增殖，雌二醇抑制其增殖，miR-21-5p的抑制剂antago-miR、miR-223-3p的激动剂、HIF-1α的抑制剂KC7F2及PARP-1的抑制剂PJ34均可以抑制PDGF诱导的右心室心肌细胞过度增殖。本项目通过患者血样筛选到和肺动脉高压患者紧密相关的microRNA，并在动物实验中进行验证，发现了雌激素通过调节microRNA来调控和肺血管增殖和右心重构的可能机制。这些研究结果对进一步深入研究性激素和microRNA在肺动脉高压患者发病中的机制有重要作用。