Improvement of osteogenic differentiation in umbilical cord-derived human mesenchymal stem cells through specific...

Umbilical cord-derived human mesenchymal stem cells (UC-hMSCs) are multipotent stem cells with great potential for treating bone diseases. Although they can be easily isolated from umbilical cord tissue, their osteogenic differentiation is less efficient than differentiation of bone marrow-derived hMSCs (BM-hMSCs). Improving osteogenic differentiation of UC-hMSCs is essential for their clinical use. This study identified specific microRNAs (miRNAs) that inhibit osteogenic differentiation and explored their regulatory mechanisms to improve the osteogenic potential of UC-hMSCs. High-throughput miRNA expression analysis was performed to identify miRNAs involved in osteogenic differentiation. Quantitative real-time RT-PCR confirmed the expression levels of these miRNAs during osteogenic differentiation. The effects of specific anti-miRNAs on osteogenic differentiation were evaluated using alkaline phosphatase (ALP) activity, Alizarin Red S staining, and osteogenic gene expression assays. Analysis revealed significant differential expression of 806 miRNAs in high-osteogenic UC-hMSCs and 760 miRNAs in low-osteogenic UC-hMSCs. Four miRNAs-miR-21, miR-27b, miR-29a, and let-7b-were significantly down-regulated during osteogenic differentiation in high-osteogenic UC-hMSCs but remained elevated in low-osteogenic UC-hMSCs. Inhibition of these miRNAs using specific anti-miRs significantly increased osteogenic gene expression, ALP activity, and matrix mineralization. These effects could be partially mediated by modulation of the PI3K/Akt and Wnt/β-catenin signaling pathways, which led to the up-regulation of RUNX2 expression in UC-hMSCs. Our findings indicate that miR-21, miR-27b, miR-29a, and let-7b are important regulators of osteogenic differentiation in UC-hMSCs. Targeting these miRNAs could enhance osteogenic differentiation by modulating the PI3K/Akt and Wnt/β-catenin signaling pathways, leading to increased RUNX2 expression. These findings provide valuable insights into the role of specific miRNAs in regulating osteogenic differentiation of UC-hMSCs and highlight potential therapeutic strategies for bone regeneration through miRNA modulation.