microRNA-265 Regulates Bone Marrow Mesenchymal Stem Cells Differentiation and Promotes Sepsis Lung Injury Repair via Transforming Growth Factor Beta 1

Our study investigates whether miR-265 regulates the differentiation of rat bone marrow mesenchymal stem cells (BMSCs) into alveolar type II epithelial cells (ATII) through TGF-f31 and promotes lung injury repair in rats with sepsis, thereby inhibiting sepsis progression. 25 patients with sepsis admitted to the Respiratory and Critical Care Medicine Department of the hospital and 17 normal controls were included. TGF-f31 level was measured by ELISA. miR-265 level was measured by qRT-PCR and AT II-related genes and proteins expression was analyzed by western blot and qRT-PCR. miR-265 expression was significantly higher in sepsis patients than normal group. Progenitor BMSCs were long and shuttle-shaped after 1 and 3 days of growth. Cultured MSCs had low expression of the negative antigen CD34 (4.32%) and high expression of the positive antigen CD44 (99.87%). TGF-f31 level was significantly increased with longer induction time, while miR-265 expression was significantly decreased in cell culture medium. miR-265 interference significantly decreased TGF-f31 expression. In conclusion, miR-265 inhibits BMSC differentiation to AT II via regulation of TGF-f31, thereby inhibiting sepsis progression.