Chondrogenic differentiation of bone marrow mesenchymal stem cells induced by different growth factors / 中国组织工程研究

ABSTRACT

BACKGROUND:Articular cartilage is a highly diferentiated tissue, which is very limited in its ability to repair after injury. Stem cel therapy for cartilage repair has completely solved this problem. OBJECTIVE: To investigate the mechanism that diferent growth factors induce the diferentiation of bone marrow mesenchymal stem cels into chondrocytes. METHODS:Passage 5 rat bone marrow mesenchymal stem cels were induced by diferent growth factors and their combinations, including transforming growth factor beta 1 (TGF-β1) group, TGF-β1+insulin growth factor-1 (IGF-1) group, and bone morphogenetic protein 2 (BMP-2)+IGF-1 group, TGF-β1+BMP-2 group, TGF-β1+IGF-1+ BMP-2 group, and blank control group. At 21 days of induction, cels were stained with alcian blue and alizarin red; RT-PCR was employed to detect colagen I mRNA expression. RESULTS AND CONCLUSION:Alcian blue staining showed metachromasia in the cytoplasm and mesenchyma, and proteoglycan was expressed green; alizarin red staining showed no orange calcium nodules. The bone marrow mesenchymal stem cels were preliminarily deduced to diferentiate into chondrocytes, but could not express the cel phenotypes of bone cels. In the blank control group, the expression of colagen I mRNA was negative. Compared with the TGF-β1 group, the mRNA expression of colagen I was lower in the BMP-2+IGF-1 group, but higher in the TGF-β1+BMP-2 group and TGF-β1+IGF-1+BMP-2 group (P < 0.05). Moreover, the expression of colagen I mRNA was highest in the TGF-β1+IGF-1+BMP-2 group (P < 0.05). These findings indicate that TGF-β1 alone is able to induce the chondrogenic diferentiation of bone marrow mesenchymal stem cels, and the combination of TGF-β1, IGF-1 and BMP-2 can play the biggest role to induce the chondrogenic diferentiation of bone marrow mesenchymal stem cels.