Circulating miRNA analysis in Pulmonary Arterial Hypertension patients, overexpression of miR-3168 downregulates BMPR2 and impairs angiogenesis in vitro. Circulating miRNA analysis in Pulmonary Arterial Hypertension patients, overexpression of miR-3168 downregulates BMPR2 and impairs angiogenesis in vitro

Pulmonary Arterial Hypertension (PAH) is a rare disease where the thickening of the precapillary pulmonary arteries ends up inducing right heart failure. Nowadays, getting an early diagnosis is complicated and usually delayed until performing right-heart catheterization. In this work, we performed small RNA sequencing in the plasma of idiopathic PAH patients and controls. We were able to find 29 differentially expressed microRNAs and validate 7 of them in a nationwide cohort (let-7a-5p, let-7b-5p, let-7c-5p, let-7f-5p, miR-9-5p, miR-31-5p, miR-3168). We then used classification models to analyze their potential as PAH predictors. In the first half of our cohort, we obtained a model with an AUC of 0.888. Although, this value lowered to 0.738 after using this model in the whole cohort of patients. Also, we validated the effect of miR-3168, a novel upregulated miRNA in PAH patients that targets the BMPR2 and impairs angiogenesis as measured in tube formation assay. In conclusion, we found novel downregulated and upregulated microRNAs in idiopathic PAH patients. We developed a 3-microRNA signature for diagnosis and validated in vitro that miR-3168 targets BMPR2 and impairs angiogenesis. Overall design: Differential expression analysis between Pulmonary Arterial Hypertension patients and healthy donors matched by age

肺动脉高压（Pulmonary Arterial Hypertension, PAH）是一种罕见疾病，其病理特征为毛细血管前肺动脉壁增厚，最终诱发右心衰竭。目前，肺动脉高压的早期诊断颇具挑战性，通常需待实施右心导管术后方可确诊。本研究对特发性肺动脉高压（idiopathic PAH）患者及健康对照的血浆样本开展小RNA测序，鉴定出29个差异表达的微小RNA（microRNA），并在全国性队列中验证了其中7个的表达水平：let-7a-5p、let-7b-5p、let-7c-5p、let-7f-5p、miR-9-5p、miR-31-5p及miR-3168。随后，本研究利用分类模型分析上述分子作为肺动脉高压预测因子的潜力：在队列的前半部分，我们构建的模型曲线下面积（Area Under the Curve, AUC）达0.888；但将该模型应用于全队列患者时，其AUC降至0.738。此外，本研究验证了miR-3168的生物学功能：该分子是肺动脉高压患者中新增的上调型微小RNA，可靶向结合BMPR2，并通过管形成实验证实其能够损害血管生成。综上，本研究在特发性肺动脉高压患者中发现了新的上调及下调微小RNA，构建了由3个微小RNA组成的诊断标志物组合，并在体外验证了miR-3168可靶向BMPR2并损害血管生成。整体实验设计：针对按年龄匹配的肺动脉高压患者与健康供体开展差异表达分析。