title: [Effect of mechanical tension on expressions of RhoA/Rho associated protein kinases in rat tendon stem cells in vitro].
abstract: OBJECTIVE
  To investigate the effect of different mechanical tensions on the expressions of RhoA/Rho associated protein kinases (ROCK) in rat tendon stem cells (TSCs).
  
  
  METHODS
  TSCs were isolated from the tendon tissue of male Sprague Dawley rats (aged, 2-3 months; weighing, 200-250 g) by enzymatic digestion method and cultured for 2-3 passages, then seeded on micro groovdishes. The 4% (4% stretch group) and 8% (8% stretch group) mechanical stretching was performed for 4 hours every day at 1 Hz. After 1, 2, and 3 days, the protein and mRNA expressions of RhoA and ROCK were measured by Western blot and real-time quantitative PCR. The cell proliferation was measured by cell counting kit 8. The cells were not stretched as control group.
  
  
  RESULTS
  The TSCs at passage 2 showed a cobble-stone shape and aggregation growth; TSCs seeded on micro groovdishes showed random growth, and the cells grew along the stretching direction after mechanical stretching. The mRNA expressions of RhoA and ROCK in control group, 4%, and 8% stretch groups showed an increasing tendency at 1, 2, and 3 days, showing significant difference between groups (P < 0.05). The protein expressions of RhoA and ROCK in 4% and 8% stretch groups were similar to those in control group at 1 day (P > 0.05), but the expressions in 4% and 8% stretch groups showed an increasing tendency at 2 and 3 days, which were significantly higher than those in control group (P < 0.05). The cell proliferation of 8% stretch group was significantly lower than that of 4% stretch group and control group at each time point (P < 0.05), but no significant difference was found between 4% stretch group and control group (P > 0.05).
  
  
  CONCLUSIONS
  The expressions of RhoA and ROCK of rat TSCs are positively correlated with stretch intensity. So RhoA/ROCK may be an important molecule in TSCs after mechanical stretching.
authors: Lin
authors: L
authors: Ma
authors: Kanglai
authors: K
authors: Tang
authors: Binghua
authors: B
authors: Zhou
authors: Guanghua
authors: G
authors: Yang
authors: Wan
authors: W
authors: Chen
authors: Miduo
authors: M
authors: Mu
authors: Chengsong
authors: C
authors: Yuan
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D066298:In Vitro Techniques; D008297:Male; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D013234:Stem Cells / Q000378:metabolism*; D013314:Stress, Mechanical; D013710:Tendons / Q000166:cytology* / Q000378:metabolism; D054460:rho-Associated Kinases / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein
chemical_list: D011494:Protein Kinases; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein