miR-124-3p promotes proliferation and inhibits apoptosis in cultured palatal mesenchymal cells

Cleft lip and palate (CLP) are common congenital craniofacial anomalies, but the post-transcriptional mechanisms regulating palatal shelf growth remain incompletely understood. In this study, small RNA sequencing was used to profile miRNA expression during murine palatal shelf development, and miR-124-3p was selected for functional assessment. In situ hybridization detected miR-124-3p in palatal tissues at multiple embryonic stages. Cultured embryonic palatal mesenchymal (EPM) cells were transfected with a miR-124-3p mimic or inhibitor and assessed by RT-qPCR, CCK-8, EdU, Hoechst staining, and flow cytometry. Increasing miR-124-3p levels enhanced measures of EPM cell proliferative activity and reduced apoptosis, whereas miR-124-3p inhibition produced the opposite effects. The sequencing and target-prediction analyses were exploratory and did not establish a direct downstream target. These in vitro findings identify miR-124-3p as a candidate regulator of palatal mesenchymal cell behavior. Organ culture or in vivo studies and direct target-validation experiments are needed to determine its role during palatogenesis.