title: [Effect of basic fibroblast growth factor and parathyroid hormone-related protein on early and late chondrogenic differentiation of rabbit bone marrow mesenchymal stem cells induced by transforming growth factor beta 1].
abstract: OBJECTIVE
  To explore the impact of basic fibroblast growth factor (bFGF) and parathyroid hormone-related protein (PTHrP) on early and late chondrogenic differentiation of rabbit bone marrow mesenchymal stem cells (BMSCs) induced by transforming growth factor beta 1 (TGF-beta1).
  
  
  METHODS
  BMSCs were isolated from 3 healthy Japanese rabbits (2-month-old, weighing 1.6-2.1 kg, male or female), and were clutured to passage 3. The cells were put into pellet culture system and were divided into 5 groups according to different induce conditions: TGF-beta1 group (group A), TGF-beta1/bFGF group (group B), TGF-beta1/21 days bFGF group (group C), TGF-beta1/PTHrP group (group D), and TGF-beta1/21 days PTHrP group (group E). At the beginning, TGF-beta1 (10 ng/mL) was added to all groups, then bFGF and PTHrP (10 ng/mL) were added to groups B and D respectively; bFGF and PTHrP (10 ng/mL) were added to groups C and E at 21 days respectively. The gene expressions of collagen type I (Col I), Col II, Col X, matrix metalloproteinases (MMP)-13, and alkaline phosphatase (ALP) activity were detected once every week for 6 weeks. The 1, 9-dimethylmethylene blue (DMMB) staining was used to observe the extracellular matrix secretion at 6 weeks.
  
  
  RESULTS
  The expression of Col I in groups C and E showed a significant downward trend after 3 weeks; the expression in group A was significantly higher than that in groups C and E at 4 and 5 weeks (P < 0.05), and than that in groups B and D at 3-6 weeks (P < 0.05); and significant differences were found between groups B and C at 3 and 4 weeks, and between groups D and E at 3 weeks (P < 0.05). After 3 weeks, the expressions of Col II and Col X in groups C and E gradually decreased, and were significantly lower than those in group A at 4-6 weeks (P < 0.05). Groups B and D showed no significant difference in the expressions of Col II and Col X at all time points, but there was significant difference when compared with group A (P < 0.05). MMP-13 had no obvious expression at all time points in group A; significant differences were found between group B and groups A, C at 3 weeks (P < 0.05); and the expression was significantly higher in group D than in groups A and E (P < 0.05). ALP activity gradually increased with time in group A; after 4 weeks, ALP activity in groups C and E obviously decreased, and was significantly lower than that in group A (P < 0.05); there were significant differences between groups B and C, and between groups D and E at 2 and 3 weeks (P < 0.05). DMMB staining showed more cartilage lacuna in group A than in the other groups at 6 weeks.
  
  
  CONCLUSIONS
  bFGF and PTHrP can inhibit early and late chondrogenic differentiation of BMSCs by changing synthesis and decomposition of the cartilage extracellular matrix. The inhibition is not only by suppressing Col X expression, but also possibly by suppressing other chondrogenic protein.
authors.affiliation: Department of Orthopedics, Zhujiang Hospital of Southern Medical University, Guangzhou Guangdong, 510282, P.R.China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Liu
authors.forename: Liping
authors.initials: L
authors.lastname: He
authors.forename: Jing
authors.initials: J
authors.lastname: Tian
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D018929:Cell Culture Techniques / Q000379:methods; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D020219:Chondrogenesis / Q000187:drug effects; D024043:Collagen Type II / Q000378:metabolism; D024121:Collagen Type X / Q000378:metabolism; D005260:Female; D016222:Fibroblast Growth Factor 2 / Q000008:administration & dosage*; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D044162:Parathyroid Hormone-Related Protein / Q000008:administration & dosage*; D011817:Rabbits; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods*; D053773:Transforming Growth Factor beta1 / Q000008:administration & dosage
chemical_list: D024043:Collagen Type II; D024121:Collagen Type X; D044162:Parathyroid Hormone-Related Protein; D053773:Transforming Growth Factor beta1; D016222:Fibroblast Growth Factor 2