title: Expression of bone-related genes in bone marrow MSCs after cyclic mechanical strain: implications for distraction osteogenesis.
abstract: OBJECTIVE
  Understanding the response of mesenchymal stem cells (MSCs) to mechanical strain and their consequent gene expression patterns will broaden our knowledge of the mechanobiology of distraction osteogenesis.
  
  
  METHODS
  In this study, a single period of cyclic mechanical stretch (0.5 Hz, 2,000 microepsilon) was performed on rat bone marrow MSCs. Cellular proliferation and alkaline phosphatase (ALP) activity was examined. The mRNA expression of six bone-related genes (Ets-1, bFGF, IGF-II, TGF-beta, Cbfa1 and ALP) was detected using real-time quantitative RT-PCR.
  
  
  RESULTS
  The results showed that mechanical strain can promote MSCs proliferation, increase ALP activity, and up-regulate the expression of these genes. A significant increase in Ets-1 expression was detected immediately after mechanical stimulation, but Cbfa1 expression became elevated later. The temporal expression pattern of ALP coincided perfectly with Cbfa1.
  
  
  CONCLUSIONS
  The results of this study suggest that mechanical strain may act as a stimulator to induce differentiation of MSCs into osteoblasts, and that these bone-related genes may play different roles in the response of MSCs to mechanical stimulation.
authors.affiliation: State Key Laboratory of Oral Diseases, Sichuan University, Chengdu, China.
authors.forename: Meng-chun
authors.initials: MC
authors.lastname: Qi
authors.forename: Shu-juan
authors.initials: SJ
authors.lastname: Zou
authors.forename: Li-chi
authors.initials: LC
authors.lastname: Han
authors.forename: Hai-xiao
authors.initials: HX
authors.lastname: Zhou
authors.forename: Jing
authors.initials: J
authors.lastname: Hu
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D001696:Biomechanical Phenomena; D001854:Bone Marrow Cells / Q000502:physiology*; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation; D050659:Core Binding Factor Alpha 1 Subunit / Q000032:analysis; D016222:Fibroblast Growth Factor 2 / Q000032:analysis; D007335:Insulin-Like Growth Factor II / Q000032:analysis; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D010006:Osteoblasts / Q000502:physiology; D019857:Osteogenesis, Distraction; D039904:Pluripotent Stem Cells / Q000502:physiology; D050784:Proto-Oncogene Protein c-ets-1 / Q000032:analysis; D051381:Rats; D013314:Stress, Mechanical; D016212:Transforming Growth Factor beta / Q000032:analysis; D015854:Up-Regulation / Q000502:physiology
chemical_list: D000954:Antigens, Surface; D050659:Core Binding Factor Alpha 1 Subunit; C494043:Ets1 protein, rat; D050784:Proto-Oncogene Protein c-ets-1; D016212:Transforming Growth Factor beta; D016222:Fibroblast Growth Factor 2; D007335:Insulin-Like Growth Factor II; D000469:Alkaline Phosphatase