Effects of parathyroid hormone-related protein on osteogenic and adipogenic differentiation of human mesenchymal stem cells

OBJECTIVE: This work aims to investigate the effects of parathyroid hormone-related peptide (PTHrP) (1-86) on osteogenic and adipogenic differentiation of human mesenchymal stem cells (hMSCs) and the related mechanisms. MATERIALS AND METHODS: hMSCs were isolated and cultured in vitro. They were divided into control group, osteogenesis group, adipogenesis group, osteogenesis+PTHrP group and adipogenesis+PTHrP group. The cell proliferation and differentiation, and expression levels of osteopontin (OPN) and lipoprotein lipase (LPL) mRNA were observed. RESULTS: The proliferation rates of hMSCs in osteogenesis+PTHrP and adipogenesis+PTHrP group were significantly higher than that in control group, respectively (p < 0.01). The alkaline phosphatase (ALP)-positive osteoblasts firstly appeared in osteogenesis+PTHrP group, and Sudan IV -positive adipocytes firstly appeared in adipogenesis group. The expression level of OPN mRNA in osteogenesis+PTHrP group was significantly higher than that in osteogenesis group (p < 0.05), and that in adipogenesis+PTHrP group was also higher than adipogenesis group (p < 0.05). The expression level of LPL mRNA in osteogenesis+PTHrP group was significantly lower than that in osteogenesis group, and that in adipogenesis+PTHrP group was also lower than adipogenesis group (p < 0.05). CONCLUSIONS: The osteogenesis and adipogenesis are related to each other during the induced differentiation of hMSCs. PTHrP (1-86) can promote the osteogenic differentiation and inhibits the adipogenic differentiation for hMSCs.