Abstract
BACKGROUND: Surgical treatment alone is not effective in addressing delayed fracture healing (DFH). This study nvestigates the molecular mechanism underlying fracture healing to identify improved therapeutic strategies. METHODS: Serum samples were collected from 76 normal fracture healing (NFH) and 70 DFH patients. RT-qPCR was performed to determine LINC00662, miR-330-3p, and PTEN mRNA expression in serum and Human Bone marrow mesenchymal stem cells (HBMSCs). The diagnostic potential of LINC00662 and miR-330-3p for DFH patients was evaluated via ROC analysis. Binding sites were predicted using bioinformatic databases and validated by dual-luciferase reporter assays. HBMSCs proliferation, apoptosis and osteogenic differentiation were analyzed using CCK-8, flow cytometry, andosteogenesis-related gene expression assays. RESULTS: LINC00662 was upregulated and miR-330-3p downregulated in DFH, and the two combined could efficiently diagnose DFH. LINC00662 knockdown promoted runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), osteopontin (OPN), and alkaline phosphatase (ALP) mRNA expression, enhanced HBMSCs proliferation, and suppressed apoptosis. miR-330-3p inhibition reversed these effect. As a target of miR-330-3p, PTEN downregulation ameliorated the negative effects of miR-330-3p downregulation on HBMSCs. CONCLUSION: LINC00662 and miR-330-3p synergistically could improve the diagnostic efficiency of DFH. LINC00662 impedes fracture healing by suppressing osteogenic differentiation and proliferation of HBMSCs while promoting apoptosis in HBMSCs via the miR-330-3p/PTEN axis.