Chapter 73 Sonic Hedgehog Signaling Molecules Expression in TGF-β1-Induced Chondrogenic Differentiation of Rat Mesenchymal Stem Cells In Vitro

摘要

Sonic Hedgehog (SHH) is involved in the induction of early artilagi-nous differentiation of mesenchymal cells in the limb and in the spine. Transforming growth factor beta 1 (TGF-β1) promotes chondrogenic differentiation of bone marrow mesenchymal stem cells (MSCs), while the signaling pathway by which TGF-β1 affects chondrogenic differentiation remains obscure. This study aimed to investigate expression of SHH- signaling molecules SHH and GLI1 during TGF-β1 -induced chondrogenic differentiation of rat MSCs in vitro. TGF-β1 promoted chondrogenic differentiation of MSCs at 10 ng/ml from 7 to 21 days, demonstrated by enhancing cartilage markers collagen type Ⅱ expression during chondrogenic differentiation. Expressions of Shh and Gli1, were tested by RT-PCR and western blot analysis during chondrogenic differentiation. Expressions of Shh and Gli1 were decreased compared to the control on both mRNA and protein level during TGF-β1-induced chondrogenic differentiation of MSCs from 7 to 21 days. Altogether, these data demonstrate that inactivation of SHH-GLI1 pathway during TGF-β1-induced chondrogenic differentiation of MSCs in vitro. These findings provide new data for the mechanistic link between TGF-β1-induced chondrogenic differentiation and Hedgehog signaling pathway.