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BioMed Research International
Volume 2015, Article ID 873251, 10 pages
http://dx.doi.org/10.1155/2015/873251
Research Article

Mechanical Strain Regulates Osteogenic and Adipogenic Differentiation of Bone Marrow Mesenchymal Stem Cells

1Department of Orthopedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
2Huiqiao Department, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
3Key Laboratory of Bone and Cartilage Regenerative Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China

Received 28 December 2014; Revised 27 February 2015; Accepted 10 March 2015

Academic Editor: Cijun Shuai

Copyright © 2015 Runguang Li 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

This study examined the effects of mechanical strain on osteogenic and adipogenic differentiation of cultured MSCs by stimulating MSCs cultured in general and adipogenic differentiation media using a mechanical strain device. Markers of osteogenic (Runx2, Osx, and I-collagen) and adipogenic (PPARγ-2, C/EBPα, and lipid droplets) differentiation were examined using real-time PCR, western blot, immunocytochemical, or histochemical stain analyses. Levels of Runx2 and Osx gradually increased in MSC groups in general medium subject to strain stimulation, as compared with in unstrained groups. After adding the stress signal, I-collagen protein levels of expression were obviously promoted in cells in comparison to the controls. The levels of PPARγ-2 and C/EBPα were decreased, and the emergence of lipid droplets was delayed in MSCs groups in adipogenic differentiation medium subject to strain stimulation, as compared with in unstrained groups. Mechanical strain can promote differentiation of MSCs into osteoblasts and can impede differentiation into adipocytes. These results clarify the mechanisms underlying the effects of exercise on bone repair and reconstruction and provide a more adequate scientific basis for the use of exercise therapy in the treatment of obesity and metabolic osteoporosis.