title: p38-MAPK signaling pathway is not involved in osteogenic differentiation during early response of mesenchymal stem cells to continuous mechanical strain.
abstract: Mechanical stimuli play a significant role in the regulation of bone remodeling during orthodontic tooth movement. However, the correlation between mechanical strain and bone remodeling is still poorly understood. In this study, we used a model of continuous mechanical strain (CMS) on bone mesenchymal stem cells (BMSCs) to investigate the proliferation and osteogenic differentiation of BMSCs and the mechanism of mechano-transduction. A CMS of 10 % at 1 Hz suppressed the proliferation of BMSCs and induced early osteogenic differentiation within 48 h by activating Runx2 and increasing alkaline phosphatase (ALP) activity and mRNA expression of osteogenesis-related genes (ALP, collagen type I, and osteopontin). Regarding mitogen-activated protein kinase (MAPK) activation, CMS induced phased phosphorylation of p38 consisting of a rapid induction of p38 MAPK at 10 min and a rapid decay after 1 h. Furthermore, the potent p38 inhibitor SB203580 blocked the induction of p38 MAPK signaling, but had little effect on subsequent osteogenic events. These results demonstrate that mechanical strain may act as a stimulator to induce the differentiation of BMSCs into osteoblasts, which is a vital function for bone formation in orthodontic tooth movement. However, activation of the p38 signaling pathway may not be involved in this process.
authors: Center of Craniofacial Orthodontics, Department of Oral and Cranio-maxillofacial Science, Shanghai 9th People's Hospital, Shanghai Key Laboratory of Stomatology, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China.
authors: Peng
authors: P
authors: Zhang
authors: Yuqiong
authors: Y
authors: Wu
authors: Qinggang
authors: Q
authors: Dai
authors: Bing
authors: B
authors: Fang
authors: Lingyong
authors: L
authors: Jiang
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation; D049109:Cell Proliferation; D048430:Cell Shape; D002470:Cell Survival; D002478:Cells, Cultured; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism; D007093:Imidazoles / Q000494:pharmacology; D020935:MAP Kinase Signaling System; D040542:Mechanotransduction, Cellular; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D010012:Osteogenesis; D011725:Pyridines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013312:Stress, Physiological; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D007093:Imidazoles; D011725:Pyridines; C493717:Runx2 protein, rat; D048051:p38 Mitogen-Activated Protein Kinases; D000469:Alkaline Phosphatase; C093642:SB 203580