Efeito da triiodotironina na expressão das proteínas ósseas durante a diferenciação osteogênica de células-tronco mesenquimais

OBJECTIVE: The aim of this study was to evaluate the effect of T3 on the expression of osteocalcin, osteopontin and collagen I during osteogenic differentiation of mesenchymal stem cells (MSC). MATERIALS AND METHODS: The bone marrow cells of Wistar rats with 30 days of age were extracted, cultured and separated into five groups: control (undifferentiated), differentiated (osteogenic stimulus) and differentiated with T3 (10(-3) nM, 10(-2) nM and 100 nM). For each group, four samples were cultured and were analyzed by real time RT-PCR at 7, 14 and 21 days for quantification of gene transcripts for osteocalcin, osteopontin and collagen I. RESULTS: All the different groups without T3 or with T3 regardless of the concentration, showed the collagen I expression significantly lower expression, and osteocalcin and osteopontin expression significantly greater than that of undifferentiated MSC. Nevertheless, the group T3 100 nM showed higher expression of osteocalcin and a similar expression of the osteoblast culture. CONCLUSION: In conclusion, the triiodothyronine does not affect the expression of osteopontin and collagen I, but increases ostecalcin expression during osteogenic differentiation in vitro of the MSC, and this effect is dose-dependent.