miR-302 regulates the osteogenic and adipogenic differentiation of adipose-derived mesenchymal stem cells / 中国组织工程研究

ABSTRACT

BACKGROUND:Mesenchymal stem cels have the capacity of self-renewal and differentiation into certain lineage cels under appropriate conditions. But many mechanisms are unknown until now. OBJECTIVE:To clarify the role of miR-302 in the regulation of osteogenic and adipogenic differentiation of adipose-derived mesenchymal stem cels. METHODS:Chemicaly synthesized miR-302 specific mimics were transfected into adipose-derived mesenchymal stem cels as experimental group. miR-NC, miR-302b negative control mimics, was transfected into another cels as control group. By the experiments of alkaline phosphatase staining, alkaline phosphatase activity assay, alizarin red staining, oil red O staining and extraction test, the effect of miR-302 upregulation on the adipogenic and osteogenic differentiation of adipose-derived mesenchymal stem cels was analyzed and compared. Western blot assay was used to detect the expression of Runx2 and alkaline phosphatase after regulation of miR-302. RESULTS AND CONCLUSION: (1) Overexpression of miR-302 decreased the precipitate and activity of alkaline phosphatase significantly as compared with the control group (P < 0.05). (2) Overexpression of miR-302 inhibited the formation of mineral deposits and calcium nodules, and the number of calcium nodules in the experimental group was significantly lower than that in the control group (P < 0.05). (3) The number of cels positive for oil red O staining was significantly higher in the experimental group than the control group, which further showed the absorbance values of oil red O staining in the experimental group obtained in the extraction test were significantly increased (P < 0.05). (4) At 6 days of osteogenic induction, the expressions of Runx2 and alkaline phosphatase in the experimental group were decreased to different extents. These findings indicate that overexpression of miR-302 can suppress osteogenesis and accelerate adipocytes generation of adipose-derived mesenchymal stem cels. miR-302 plays a two-way regulatory role to balance the osteogenic and adipogenic differentiation of mesenchymal stem cels.