Non-invasive approach for evaluation of pulmonary hypertension using extracellular vesicle-associated small non-coding RNA

Extracellular vesicles are released by numerous cell types of the human body under physiological but also under pathophysiological conditions. They are important for cell-cell communication and carry specific signatures of peptides and RNAs. In this study, researchers from Justus-Liebig-University Giessen aimed to determine whether extracellular vesicles isolated from patients with pulmonary hypertension show a disease specific signature of small non-coding RNAs and thus have the potential to serve as diagnostic and prognostic biomarkers. Extracellular vesicles were isolated from the serum of 23 patients with chronic thromboembolic pulmonary hypertension (CTEPH) and 23 controls using two individual methods: a column-based method or by precipitation. Extracellular vesicle- associated RNAs were analyzed by next-generation sequencing applying molecular barcoding, and differentially expressed small non-coding RNAs were validated by quantitative real-time polymerase chain reaction (qRT-PCR). The researchers identified 18 microRNAs and 21 P-element induced wimpy testis (PIWI)-interacting RNAs (piRNAs) or piRNA clusters that were differentially expressed in CTEPH patients compared with controls. Bioinformatic analysis predicted a contribution of these piRNAs to the progression of cardiac and vascular remodeling. Expression levels of DQ593039 correlated with clinically meaningful parameters such as mean pulmonary arterial pressure, pulmonary vascular resistance, right ventricular systolic pressure, and levels of N-terminal pro-brain natriuretic peptide. Thus, they identified the extracellular vesicle- derived piRNA, DQ593039, as a potential biomarker for pulmonary hypertension and right heart disease.

Differentially regulated EV-associated miRNAs in chronic thromboembolic
pulmonary hypertension (CTEPH) vs. control individuals

EV- associated miRNAs were isolated using the exoRNeasy protocol. (A) RNA sequencing (n = 3) was performed using TrueQuant technology followed by sequencing. Depicted is the log2 (fold change) of the samples compared with the median of the controls. (B) miRNA abundance was standardized to the spike-in control cel-miR-39 and compared with that of healthy controls. The mean of the individual groups is depicted as a line. Significance was calculated using Student’s t-test with Welch’s correction. * p < 0.05, ** p < 0.01, *** p < 0.001.