title: [Effect of growth differentiation factor 7 on tenogenic differentiation of bone marrow mesenchymal stem cells of rat in vitro].
abstract: OBJECTIVE
  To investigate the effect of growth differentiation factor 7 (GDF-7) on the tenogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in vitro, to provide evidence for improving the efficacy of BMSCs on tendon repair.
  
  
  METHODS
  BMSCs were isolated from bone marrow tissue of green fluorescent protein rats by density gradient centrifugation method. Chondrogenic, osteogenic, and adipogenic differentiation assays were used to demonstrate the multi-differentiation potential of the BMSCs. BMSCs at passage 3 were cultured and divided into 4 groups according to different concentrations of GDF-7 (0, 12.5, 25.0, and 50.0 ng/mL): group A, B, C, and D, respectively. After cultured for 2 weeks in vitro, the mRNA expressions of scleraxis, tenomodulin, tenascin C, and collagen type I were detected by real-time fluorescent quantitative PCR method, the protein expressions of tenomodulin, tenascin C, and collagen type I by immunocytochemistry staining in 4 groups, and the protein expressions of tenomodulin by Western blot in groups A and C.
  
  
  RESULTS
  BMSCs had osteogenic, chondrogenic, and adipogenic differentiation potentials. The mRNA expressions of tenomodulin in groups B, C, and D were 2.85, 3.41, and 3.07 times higher than that in group A, respectively; the mRNA expressions of scleraxis in groups B, C, and D were 2.13, 1.50, and 2.56 times higher than that in group A, respectively; and the mRNA expressions of tenascin C in groups B, C, and D were 2.45, 2.86, and 1.88 times higher than that in group A, respectively. There were significant differences between groups B, C, D and group A (P < 0.05), while there was no significant difference among groups B, C, and D (P > 0.05). The mRNA expressions of collagen type I in groups B and C were 1.92 and 2.45 times higher than that in group A, showing significant differences between groups B, C and group A (P < 0.05), but no significant difference between groups A and D (P > 0.05). Immunocytochemistry staining showed that the protein expressions of tenomodulin, tenascin C, and collagen type I were detected in groups B, C, and D but not in group A. The results were further confirmed by Western blot results which showed higher protein expression of tenomodulin in group C than in group A.
  
  
  CONCLUSIONS
  GDF-7 can be used to promote tenogenic differentiation of rat BMSCs in vitro.
authors: Department of Orthopaedics, General Hospital of Chinese PLA, Beijing 100853, PR China.
authors: Ming
authors: M
authors: Ni
authors: Yunfeng
authors: Y
authors: Rui
authors: Qiming
authors: Q
authors: Chen
authors: Yan
authors: Y
authors: Wang
authors: Gang
authors: G
authors: Li
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology*; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D051381:Rats
chemical_list: D019485:Bone Morphogenetic Proteins; C086559:growth differentiation factor 7