Plasma microRNAs levels associate with the outcome of ARDS patients

Background: Mesenchymal stem cells (MSC) are stromal cells with renew ability for multilineage differentiation. Therefore MSC has been considered as a therapy method for rebuilding alveoli structure and repairing the function of pulmonary vascular endothelial cells (VEC). However, whether MSC can play a therapeutic role in ARDS patients depends on different ARDS phenotypes. Recent studies about microRNAs (miRNAs) proved that miRNAs played important roles in MSC regulating function and activity of VEC which may affect therapeutic response and outcome to different ARDS patients, but few studies focused on this field. The purpose of our study is that plasma miRNAs regulated VEC’s function and specific miRNAs which were related to MSC and VEC (MSC‑VEC‑miRNAs) expressed differently between survival and non-survival ARDS patients. We aim to find specific MSC‑VEC‑miRNAs which are associated with the outcome of ARDS patients. Methods: We obtained MSC-VEC -miRNAs through searching PUBMED database. A number of 101 ARDS patients were screened and 57 of them were included in our research within 24 hours of admission to ICU. We then collected their clinical data and their blood samples, then we did real-time PCR to test plasma levels of MSC-VEC -miRNAs. Results: Fourteen MSC-VEC -miRNAs were selected in this study. We included 57 ARDS patients and 18(31.6%) of them died on Day 28 after diagnosis. Plasma miR-26a level in non-survival group was significantly lower than that in survival group (0.33[0.09-1.17] vs. 0.97[0.17-3.49], P =0.046). Plasma miR-320 level in non-survival group was significantly higher than that in survival group (0.37[0.16-1.66] vs. 0.18[0.07-0.39], P =0.041). There was no statistical difference of other 12 miRNA between two groups. Conclusion: Plasma miR-26a and miR-320 levels have a certain predictive value for the prognosis of ARDS patients.