Diagnostic Potential of microRNAs in Extracellular Vesicles Derived from Bronchoalveolar Lavage Fluid for Pneumonia-A Preliminary Report.

Current clinical needs require the development and use of rapid and effective diagnostic indicators to accelerate the identification of pneumonia and the process of microbiological diagnosis. MicroRNAs (miRNAs) in extracellular vesicles (EVs) have become attractive candidates for novel biomarkers to evaluate the presence and progress of many diseases. We assessed their performance as biomarkers of pneumonia. Patients were divided into the pneumonia group (with pneumonia) and the control group (without pneumonia). We identified and compared two upregulated miRNAs in EVs derived from bronchoalveolar lavage fluid (BALF-EVs) between the two groups (PmiR-17-5p = 0.009; PmiR-193a-5p = 0.031). Interestingly, in cell-debris pellets and EVs-free supernatants derived from bronchoalveolar lavage fluid (BALF-cell-debris pellets and BALF-EVs-free supernatants), total plasma, and EVs derived from plasma (plasma-EVs), the expression of miR-17-5p and miR-193a-5p showed no difference between pneumonia group and control group. In vitro experiments revealed that miR-17-5p and miR-193a-5p were strikingly upregulated in EVs derived from macrophages stimulated by lipopolysaccharide. MiR-17-5p (area under the curve, AUC: 0.753) and miR-193a-5p (AUC: 0.692) in BALF-EVs are not inferior to procalcitonin (AUC: 0.685) in the diagnosis of pneumonia. Furthermore, miR-17-5p and miR-193a-5p in BALF-EVs had a significantly higher specificity compared to procalcitonin and could be served as a potential diagnostic marker. MiR-17-5p and miR-193a-5p in EVs may be involved in lung inflammation by influencing the forkhead box O (FoxO) signaling pathway and protein processing in endoplasmic reticulum. This study is one of the few studies which focused on the potential diagnostic role of miRNAs in BALF-EVs for pneumonia and the possibility to use them as new biomarkers for a rapid and early diagnosis.

CAP1 was associated with actin and involved in Schwann cell differentiation and motility after sciatic nerve injury.

Adenylate cyclase-associated protein 1 (CAP1), a member of cyclase-associated proteins that regulating actin dynamics, was shown to regulate actin filaments, localize to dynamic actin structures and mediate such processes as establishment of cell polarity, motility, morphogenesis, receptor-mediated endocytosis and mRNA location. But little is known about the role of CAP1 during peripheral nervous system injury. Here, we found the spatiotemporal protein expression of CAP1 after sciatic nerve crush. After crush, CAP1 had an increased protein expression level, reached a peak at about day 5 and then returned to the normal level at 4 weeks, similar to Oct-6. Besides, in 5-day injured tissue, using double immunofluorescent staining we found CAP1 had a colocalization with S100 and Oct-6. In vitro, during the process of cAMP-induced Schwann cells differentiation, we observed enhanced expression of CAP1 and P0. Specially, CAP1-specific siRNA-tranfected SCs did not show significant actin structure which form cellure surface tension and protrusion shape after cAMP treatment. And we observed the interaction of CAP1 with actin and that CAP1-specific siRNA-transfected SCs had a decreased motility and migration. Together, all these data indicated that the change of CAP1 protein expression was associated with Schwann cells motility and differentiation after the crush of sciatic nerve.