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Journal of Diabetes Research
Volume 2014, Article ID 453940, 6 pages
http://dx.doi.org/10.1155/2014/453940
Research Article

Metformin Rescues the MG63 Osteoblasts against the Effect of High Glucose on Proliferation

1Department of Endocrinology and Metabolism, The First Affiliated Hospital of Soochow University, 188 Shizi Street, Suzhou, Jiangsu 215006, China
2Department of Endocrinology and Metabolism, Zhangjiagang First People’s Hospital, Zhangjiagang, Jiangsu 215600, China

Received 31 December 2013; Revised 2 March 2014; Accepted 26 March 2014; Published 9 April 2014

Academic Editor: Wang Chen

Copyright © 2014 Xinyu Shao et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Aims. To study the proliferation of osteoblasts and genes expression under normal glucose, high glucose, and metformin (Met). Methods. MG63 osteoblast-like cells were cultured in osteogenic medium supplemented with normal glucose (glucose 5.5 mmol/L) or high glucose (glucose 16.7 mmol/L) and metformin + high glucose (Met 300 μmol/L + glucose 16.7 mmol/L). Proliferation was detected with CCK-8 assay at days 1, 3, and 7. Real-time PCR and Western blot were performed to compare the expression of collagen I (Col I), osteocalcin (OCN), osteoprotegerin (OPG), receptor activator for NF-κB ligand (RANKL), and metal matrix proteinases 1 and 2 (MMP1, MMP2). Alkaline phosphatase (ALP) activity was also detected at days 6, 12, and 18. Results. Exposure to high glucose inhibited the proliferation of osteoblasts ( ), with suppressed OCN and OPG. Meanwhile, Col I, RANKL, MMP1, and MMP2 were unaffected. Metformin attenuated the suppression on proliferation with increased expression of Col I, OCN, and OPG, meanwhile suppressing MMP1 and MMP2. High glucose lowered the intracellular ALP, while metformin raised it. Metformin attenuated the downregulation of ALP completely at day 6, partly at day 12, but not at day 18. Conclusions. Metformin attenuated the suppression effect of high glucose to the osteoblast proliferation and gene expression, more prominently in earlier stage.