The Effects Of TGF-β₁ And BMP-2 On The Expression Of Collagen Type Ⅱ And PG Of Condylar Chondrocytes In Vitro

[Objective] To study the changes of transforming growth factor-beta₁(TGF-(?)₁) andbone morphogenetic protein-2(BMP-2) on the expression of collagen typeâ…¡and PG of mandibular condylar chondrocytes(MCCs), so that to understand themechanism of MCCs for their roles in the remodeling of mandibular cartilage.[Materials and Methods] The primary MCC separated from the mandibular condylarcartilage of eight neonatal SD rats were cultured in vitro.The second passage cellswere seeded at 3×10⁴/ml on 6-well plate(8 plates)for 24 hours,then the culturemedium was replaced by DMEM containing 0．4%FBS with different concentration ofthe growth factors for 72 hours. The expression of collagen typeâ…¡and PG wasdetected in the way of immunohistochemistry. To the control groups, cells withoutgrowth factors were also cultured in the same conditions and tested on the samemethods according to the experiment groups.[Results] It was found that TGF-(?)₁ of the different concentration, when exerted on thecultured MCC for 72 hours in vitro, had significantly improved the expression ofcollagen typeâ…¡and PG, the expression of collagen typeâ…¡showedconcentration-effect pattern from 1ng/ml to 10ng/ml ,the optimal concentration was10ng/ml. Both TGF-(?)₁ and BMP-2 had significantly improved the expression ofPG, the optimal combination was 10ng/mlTGF-(?)₁+20ng/ml BMP-2; there was nosignificantl difference of the expression of collagen typeâ…¡between the controlgroups and the experiment groups. [Conclusion] A certain concentration TGF-(?)₁ can improve the expression of collagentypeâ…¡and PG of cultured MCC in vitro, A certain concentration BMP-2 and 10ng/mlTGF-(?)₁ can cooperate to improve the expression of PG of cultured MCC in vitro.Thestudy indicates that TGF-(?)₁ and BMP-2 take an active part in the differentiation andthe phenotype of MCC.