Background: Perichondrium is recognized as a tissue with chondrogenic potential yielding cells which can be used for osteochondral repair. Factors which influence the proliferative ability and chondrocytic phenotype of such cells include age and presence of specific growth factors, i.e. TGF-beta 1. The present in vitro study assessed proliferation and markers of chondrocytic phenotype in cells extracted from the rib perichondrium of four- to five-year-old aged rabbits, and assessed the effects of exogenously added TGF-beta 1 on those cells.
Methods: Assays included 3H-thymidine incorporation (cell proliferation), 35S-sulfate incorporation (proteoglycan synthesis) and quantitative RT-PCR for determination of type II collagen gene expression.
Results: The results demonstrated that addition of TGF-beta 1 to the culture media stimulated thymidine incorporation and proteoglycan synthesis up to four- and five-fold, respectively, in aged perichondrium-derived cells. Moreover, the exogenous addition of TGF-beta 1 to the culture media resulted in an upregulation of transcriptional expression of the type II collagen gene.
Conclusions: In summary, the present study has demonstrated that exogenously added TGF-beta 1 can stimulate proliferation and chondrocytic phenotype in aged perichondrium-derived cells in vitro.