title: Effect of the same mechanical loading on osteogenesis and osteoclastogenesis in vitro.
abstract: OBJECTIVE
  To investigate the influence of the same mechanical loading on osteogenesis and osteoclastogenesis in vitro.
  
  
  METHODS
  Primary osteoblasts, bone marrow-derived mesenchymal stem cells (BMSCs, cultured in osteoinductive medium) and RAW264.7 cells cultured in osteoclast inductive medium were all subjected to a 1000 μstrain (μs) at 1 Hz cyclic mechanical stretch for 30 min (twice a day).
  
  
  RESULTS
  After mechanical stimulation, the alkaline phosphatase (ALP) activity, osteocalcin protein level of the osteoblasts and BMSCs were all enhanced, and the mRNA levels of ALP and collagen type I increased. Additionally, extracellular-deposited calcium of both osteoblasts and BMSCs increased. At the same time, the activity of secreted tartrate-resistant acid phosphatase, the number of tartrate-resistant acid phosphatase-positive multinucleated cells, matrix metalloproteinase-9 protein levels of RAW264.7 cells and the extracellular calcium solvency all decreased.
  
  
  CONCLUSIONS
  The results demonstrated that 1000 μs cyclic mechanical loading enhanced osteoblasts activity, promoted osteoblastic differentiation of BMSCs and restrained osteoclastogenesis of RAW264.7 cells in vitro.
authors.affiliation: College of Biotechnology, Guilin Medical University, Guilin 541004, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Guo
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Yinqin
authors.initials: Y
authors.lastname: Liu
authors.forename: Haitao
authors.initials: H
authors.lastname: Wang
authors.forename: Chun
authors.initials: C
authors.lastname: Guo
authors.forename: Xizheng
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002454:Cell Differentiation; D002478:Cells, Cultured; D051379:Mice; D008810:Mice, Inbred C57BL; D010006:Osteoblasts / Q000166:cytology; D010010:Osteoclasts / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology*; D000071681:Tartrate-Resistant Acid Phosphatase / Q000378:metabolism
chemical_list: D000071681:Tartrate-Resistant Acid Phosphatase