Effect of Insulin-Like Growth Factor-1 on Bone Formation of Bone Marrow Mesenchymal Stem Cells Under High Glucose Environment by Regulating Insulin Like Growth Factor Binding Protein 2(IGFBP-2)/p38 Pathway

Abstract

Diabetes easily affects the biological properties of bone marrow mesenchymal stem cells (BMSCs). Insulin-like growth factor-1 (IGF-1) promotes bone healing during osteoporotic fractures. However, IGF-1's effect on BMSCs high glucose is unclear. Rat BMSCs were assigned into control group, high glucose group, and IGF-1 group in which BMSCs were transfected with pc-DNA 3.1-IGF-1 plasmid on the basis of high glucose followed by analysis of IGF-1, RUNX2 and OPN mRNA level by real time PCR, cell proliferation by MTT assay, alkaline phosphatase (ALP) activity, IGFBP-2 level by ELISA, and p38 phosphorylation by Western blot. High glucose group showed significantly decreased IGF-1, RUNX2 and OPN mRNA level, reduced ALP activity, IGFBP-2 expression and p38 phosphorylation compared to control group (P < 0 05). Transfection of IGF-1 plasmid under high-glucose environment significantly upregulated IGF-1, RUNX2 and OPN mRNA, increased ALP activity, IGFBP-2 expression and p38 phosphorylation compared to high-glucose group (P < 0 05). IGF-1 expression is reduced in high glucose environment. Up-regulation of IGF-1 can promote BMSCs osteogenic differentiation through the IGFBP-2/p38 pathway.