title: [Effect of transforming growth factor β(1) and insulin-like growth factor-I on extracelluar matrix synthesis of self-assembled constructs of goat temporomandibular joint disc].
abstract: OBJECTIVE
  To examine the effects of high and low concentrations of transforming growth factor (TGF) β(1) and insulin-like growth factor-I (IGF-I) on the extracelluar matrix synthesis of the self-assembled constructs of temporomandibular joint (TMJ) disc.
  
  
  METHODS
  The experimental groups of self-assembled constructs were exposed to IGF-I (10, 100 µg/L) and TGF-β(1) (5, 50 µg/L), the control groups were not added with any growth factors. All groups were examined at 3 and 6 weeks for gross morphological, histological, and biochemical changes. Safranin-O/fast green staining was used to examine glycosaminoglycan (GAG) distribution, picrosirius red and immunohistochemical staining to observe type I collagen distribution. Type I collagen contents were tested by ELISA assay kit, GAG contents were measured by Blyscan GAG assay kit, and the cell numbers were quantified with a Picogreen reagent kit.
  
  
  RESULTS
  The growth factor groups all upregulated the matrix synthesis of the self-assembled constructs compared with control groups. TGF-β(1) (5 µg/L) and IGF-I (10 µg/L) were the two most potent concentration in increasing type I collagen and GAG synthesis and cells proliferation. IGF-I group (10 µg/L) produced nearly 2 times (109.16 ± 5.12 µg) as much type I collagen as the control group (69.13 ± 5.94 µg) at 3 weeks. The matrix contents and the number of the proliferated cells in control group and all GF groups at 6 weeks were more than those at 3 weeks.
  
  
  CONCLUSIONS
  IGF-I (10 µg/L) is the most beneficial growth factor and can be applied in tissue-engineering stratigies of the temporomandibular joint disc. At the same time, the exposure time of growth factors is another key factor that affects matrix synthesis of TMJ disc constructs.
authors.affiliation: Department of Prosthedontics, Institute of Stomatology, Lanzhou University, China. kanghong@lzu.edu.cn
authors.forename: Hong
authors.initials: H
authors.lastname: Kang
authors.forename: Yan-da
authors.initials: YD
authors.lastname: Bi
authors.forename: Zhen-Qiang
authors.initials: ZQ
authors.lastname: Li
authors.forename: Meng-Yi
authors.initials: MY
authors.lastname: Qi
authors.forename: Er-Mei
authors.initials: EM
authors.lastname: Peng
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D024042:Collagen Type I / Q000096:biosynthesis*; D005109:Extracellular Matrix / Q000378:metabolism*; D006025:Glycosaminoglycans / Q000096:biosynthesis*; D006041:Goats; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D019224:Temporomandibular Joint Disc / Q000166:cytology / Q000378:metabolism; D023822:Tissue Engineering / Q000379:methods; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology*
chemical_list: D024042:Collagen Type I; D006025:Glycosaminoglycans; D053773:Transforming Growth Factor beta1; D007334:Insulin-Like Growth Factor I