Down-Regulation of Notch-2 Promotes the Osteogenic Differentiation of Bone Marrow Stromal Cells in High Glucose Environment by Targeting Fat Mass and Obesity-Associated Protein

Abstract

BMSCs Differentiation into osteoblasts is beneficial for treating osteoporosis. Notch signaling pathway regulates the proliferation of BMSCs. However, Notch-2's effect on osteogenic differentiation of BMSCs in high glucose environment remains unclear. Rat BMSCs were isolated and divided into control group, high glucose group, Notch-2 siRNA group, in which BMSCs cells were transfected with Notch-2 siRNA under high glucose environment followed by analysis of Notch-2 mRNA expression by Real time PCR, cell proliferation by MTT assay, Caspase 3 activity, ALP activity, expression of osteogenic genes Runx2 and BMP-2 by Real time PCR, TNF-α and IL-2 secretion by ELISA, myeloperoxidase (MPO) and superoxide dismutase (SOD) activity and FTO protein expression by Western blot. In high glucose group, Notch-2 expression was increased with inhibited cell proliferation, increased Caspase 3 activity and decreased ALP activity. Meanwhile, high glucose significantly increased MPO content, decreased SOD activity, increased TNF-α and IL-2 secretion and FTO expression, and reduced Runx2 and BMP-2 expression (P < 0.05); Notch-2 siRNA transfection significantly down-regulated Notch-2 expression, promoted BMSCs cell proliferation, decreased Caspase 3 activity and increased ALP activity. In addition, it also significantly decreased MPO content, increased SOD activity, decreased TNF-α and IL-2 and FTO expression as well as increased Runx2 and BMP-2 expression (P < 0.05). Notch-2 is upregulated in BMSCs under high glucose. Down-regulation of Notch-2 in BMSCs under high glucose environment could promote BMSCs proliferation and osteogenic differentiation.