Intrinsic microRNA regulatory programs define lineage-specific differentiation in human mesenchymal stem cells of different origin - dental pulp- and fat tissue-derived.

Cell fate determination and terminal differentiation are shaped by intrinsic molecular programs that coordinate lineage-specific gene expression. In mesenchymal stem cells (MSCs), variability in osteogenic efficiency among distinct tissue sources remains poorly understood and cannot be fully explained by differentiation conditions alone. Increasing evidence indicates that post-transcriptional regulatory mechanisms, particularly those mediated by microRNAs (miRNAs), are closely associated with differentiation outcomes. Here, we investigated whether intrinsic miRNA expression landscapes are associated with lineage-associated differences in late-stage mineralization, in the context of potential donor-related variability of human MSCs. Dental pulp stem cells (DPSCs) and processed lipoaspirate (PLA)-derived MSCs were cultured under identical osteogenic induction conditions and analyzed longitudinally throughout differentiation. Both cell populations fulfilled established mesenchymal phenotypic criteria and successfully initiated osteogenic commitment. However, DPSCs exhibited significantly enhanced extracellular matrix mineralization at mid-to-late stages of differentiation, suggesting divergence at later stages of extracellular matrix mineralization rather than at early lineage commitment. Temporal small RNA sequencing performed at days 0, 7, 14, and 21 revealed progressive remodeling of miRNA expression in both MSC sources. Direct comparison at the mature osteoblast stage identified a discrete set of ten miRNAs differentially expressed between DPSCs and PLA-derived cells. DPSCs displayed reduced expression of several miRNAs previously associated with inhibitory roles in osteogenic pathways. Network-based analyses indicated convergence of these miRNAs on gene programs involved in skeletal development and extracellular matrix organization. Targeted validation confirmed decreased expression of miR-10a-5p and miR-196a-5p, accompanied by increased expression of osteogenesis-associated genes, including BMP1 and MMP16, in DPSCs. Collectively, these findings show that lineage-specific miRNA expression patterns are associated with distinct osteogenic maturation trajectories in human MSCs. This work identifies an intrinsic post-transcriptional signature through which cellular origin may influence terminal differentiation outcomes and suggests that such miRNA profiles may serve as informative molecular biomarkers in the future for the selection and characterization of mesenchymal stem cells intended for human bone tissue engineering applications.