Down-regulation of exosomal microRNA-224-3p derived from bone marrow–derived mesenchymal stem cells potentiates angiogenesis in traumatic osteonecrosis of the femoral head

Traumatic osteonecrosis of the femoral head (ONFH) is a condition leading to the collapse of the femoral head, and the primary treatment is a total hip replacement, which has a poor prognosis. The current study was conducted with the aim of investigating the role of exosomes from bone marrow–derived mesenchymal stem cells (BM-MSCs) carrying microRNA-224-3p (miR-224-3p) in traumatic ONFH. Initially, a microarray analysis was performed to screen the differentially expressed genes and miRs associated with traumatic ONFH. Patients with traumatic and nontraumatic ONFH were enrolled, and HUVECs were obtained. The BM-MSCs–derived exosomes were purified and characterized, after which HUVECs were cocultured with exosomes. The functional role of miR-224-3p in traumatic ONFH was determined using ectopic expression, depletion, and reporter assay experiments. Endothelial cell proliferation, migration, invasion abilities, and angiogenesis were evaluated. Based on microarray analysis, miR-224-3p was found to be down-reg...