title: [Effects of fluid shear stress on apoptosis of osteoblasts and expression of bcl-2,Bax and caspase-3].
abstract: OBJECTIVE
  The aim of the present investigation is to evaluate the effects of fluid shear stress on the cells of osteoblasts and to determine the mechanisms involved.
  
  
  METHODS
  The fluid shear stress with a magnitude of 0 (control group), 0.6, 1.0, 2.0, 3.0, 4.0, 5.0 Pa was exerted on the third passage of osteoblasts for 1 hour,and incubation in static condition for 24 hours. The cell apoptotic index was tested by the terminal transferase dUTP nick end-labeling(TUNEL) method. The expression of bcl-2 ,Bax and caspase-3 were detected by immunohistochemical method. Statistical analysis was performed using SPSS11.5 software package for one-way ANOVA.
  
  
  RESULTS
  The apoptosis of osteoblasts and the expression of bcl-2, Caspase-3 were not affected significantly by the fluid shear stress with a magnitude from 0 to 2.0 Pa(P>0.05) . But in the 3.0,4.0 and 5.0 Pa groups, the number of apoptotic cells and the expression of caspase-3 increased while the expression of bcl-2 decreased(P<0.05).There was no significant difference in expression of Bax in all groups.
  
  
  CONCLUSIONS
  The physiological fluid shear stress does not affect apoptosis of osteoblasts. However,the fluid shear stress of over-magnitude may lead to the decrease the expression of bcl-2,which results in activation of caspase-3 and apoptosis of osteoblasts. Supported by Research Grant from Zhejiang Provincial Education Committee(Grant No.20061823).
authors.affiliation: School and Hospital of Stomatology, Wenzhou Medical College, Wenzhou 325027, Zhejiang Province, China.
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Liu
authors.forename: Jian-Feng
authors.initials: JF
authors.lastname: Ma
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.forename: Da-Feng
authors.initials: DF
authors.lastname: Zhang
authors.forename: Chuan-Tong
authors.initials: CT
authors.lastname: Liu
authors.forename: Xing
authors.initials: X
authors.lastname: Liang
mesh_terms: D017209:Apoptosis; D053148:Caspase 3 / Q000096:biosynthesis; D006801:Humans; D010006:Osteoblasts / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis; D013314:Stress, Mechanical; D051028:bcl-2-Associated X Protein / Q000096:biosynthesis
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D053148:Caspase 3