Effects of ncorsirna on proliferation and osteogenic differentiation of mesenchymal stem cells in high glucose microenvironment

Background: Chronic hyperglycemia enhances osteoporosis in diabetic patients mainly by inhibiting osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). Nuclear receptor co repressor (NCoR) has been reported to negatively modulate osteogenic differentiation of Rat BMSCs in a standard culture medium, conversely, its knockdown promoted osteogenic differentiation. In this study, we investigated the effects of NCoR knockdown on proliferation and osteogenic differentiation of MSCs under a high glucose microenvironment. Methods: Cells from Wistar rats were isolated, transfected with NCoR small interfering RNA (NCoRsiRNA), cultured in various glucose concentrations (5.5, 16.5,25 and 35mmol/L) and then cell proliferation determined using methyl thiazolyltetrazolium (MTT). Osteogenic differentiation of cells cultured in normal (5.5mmol/L) and high glucose (25mmol/L) was determined through quantitative changes in mineralization (calcium accumulation), alkaline phosphatase (ALP) activity and expression of osteoblast marker genes including Runx2, osteocalcin (OCN), Osterix, bone sailoprotein (BSP) and osteopontin (OPN)using quantitative Real Time PCR. Results: NCoR knockdown in MSCs cultured in high glucose (25mmol/L) inhibited cell proliferation but resulted in increased Calcium accumulation, alkaline phosphatase (ALP) activity and elevated mRNA expression of all osteoblast related genes. Conclusion: NCoR knockdown inhibited proliferation but promoted osteogenic differentiation of BMSCs under a high glucose micro-environment.