Overexpression of miR-3168 impairs angiogenesis in Pulmonary Arterial Hypertension: Insights from circulating miRNA analysis

Abstract

AbstractBackgroundPulmonary Arterial Hypertension (PAH) is a rare disease where the thickening of the precapillary pulmonary arteries ends up inducing right heart failure. Nowadays, obtaining an early diagnosis is challenging and typically delayed until undergoing right-heart catheterization.MethodsWe performed small RNA sequencing (microRNA-seq) in the plasma of idiopathic PAH patients and controls, that we validated by qPCR. We then interrogated the role of miR-3168 in HUVECs by performing western-blot, flow cytometry and tube formation assays.ResultsWe found 29 differentially expressed microRNAs and validate 7 of them let-(7a-5p, let-7b-5p, let-7c-5p, let-7f-5p, miR-9-5p, miR-31-5p, miR-3168) in a nationwide cohort of 120 patients and 110 controls. We then used classification models to analyze their potential as PAH predictor. 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. Additionally, we validated the effect of miR-3168, a novel upregulated miRNA in PAH patients which targetsBMPR2,and impairs angiogenesis, as assessed by the tube formation assay.ConclusionWe identified novel downregulated and upregulated microRNAs in idiopathic PAH patients, developed a 3-microRNA signature for diagnosis, and validatedin vitrothat miR-3168 targetsBMPR2,thereby impairing angiogenesis.