Human umbilical cord mesenchymal stem cell-derived exosomal miR-199a-3p inhibits the MAPK4/NF-κB signaling pathway to relieve osteoarthritis

Figure 2 Human umbilical cord mesenchymal stem cell-derived exosomes relieve interleukin-1β-induced chondrocyte inflammation and apoptosis through the delivery of miR-199a-3p. A: Differential expression of microRNAs (miRNAs) in osteoarthritis was analyzed by heat and volcano maps; B: The expression levels of miR-199a-3p in CHON-001 cells were assessed via quantitative real-time polymerase chain reaction (qRT-PCR); C: The expression levels of miR-199a-3p in human umbilical cord mesenchymal stem cells and exosomes was detected by qRT-PCR; D: The efficiency of miR-199a-3p transfection was assessed in human umbilical cord mesenchymal stem cells via qRT-PCR; E: QRT-PCR analysis was conducted to determine the expression levels of miR-199a-3p in CHON-001 cells; F: An enzyme-linked immunosorbent assay was used to measure the interleukin-6, interleukin-8, and tumor necrosis factor-α levels in CHON-001 cells; G: The survival rate of CHON-001 cells was evaluated via CCK-8; H: Apoptosis was assessed through terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labelling staining (scale bar = 100 μm); I: The levels of the Bcl-2 and Bax apoptosis-related proteins were detected in CHON-001 cells using western blot analysis. ^aP < 0.05, ^bP < 0.01, ^cP < 0.001. hUC-MSCs: Human umbilical cord mesenchymal stem cells; Exos: Exosomes; NC: Normal control; NC mimic: Negative control mimic; NC inhibitor: Negative control inhibitor; DAPI: 4’,6-diamidino-2-phenylindole; OD: Optical density; IL: Interleukin; TNF: Tumor necrosis factor; TUNEL: Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-nick end labelling.