The Effect Of IGF-1 On The Proliferation And Osteoblast Conversion Of Fibroblast Stimulated By The RhBMP-2

OBJECTIVE:To discuss possible roles of IGF -â… on the osteoinductive activity of the fibroblast(Fb) intervened by rhBMP-2,and discuss whether the IGF-I can accelerate the osteogenesis of Fb in vitro.METHODS:Fibroblasts (Fb) come from adults of New Zealand rabbits.(Offered by the Experimental Animal Center of Shanxi Medical University).Take the skin from the back of the rabbit, the fibroblasts were isolated and purified, and they were incubated.Groups:the control group:cultured in the routine media,and don't join any induction agent and interruption factor;the rhBMP-2 group:cultured in the routine media,and join the 100ng/ml rhBMP-2;IGF-I+rhBMP-2 group:cultured in the routine media,and join 100ng/ml rhBMP-2 and 50ng/ml IGF-I.Observe the growth condition of Fb by the inverted microscope,calcium-cobalt staining, and adopt the MTT assay to detect the cell proliferation.Alkaline phosphatase (ALP) activity test and alizarin red staining were used to evaluate the ability of osteogenesis.RESULTS:1.Compared with the other two Groups, The cell proliferation of IGF-I+rhBMP-2 group is quicker and the cell growth cycle time is obviously shorter.By MTT assay,the cell of IGF-I+rhBMP-2 group harvest(P<0.05).There is no difference between the control group and the rhBMP-2 group.(P>0.05)2.Compareed with the control group,the expression of ALP is more in the rhBMP-2 group,and is the most in the IGF-I+rhBMP-2 group(P<0.01).3.The control group have no obvious calcified nodules,and some little in the rhBMP-2 group,but there are more and bigger calcified nodules in the IGF-I+rhBMP-2 group.4. After calcium-cobalt staining,in the rhBMP-2 group and IGF-I+rhBMP-2 group there are some cell particles stained from light brown to brownish-black in cytoplasm.4.After calcium-cobalt staining,in the rhBMP-2 group and IGF-I+rhBMP-2 group there are some cell particles stained from light brown to brownish-black in cytoplasm.CONCLUSION:1.Fb can transform to osteoblast under certain condition and inducing factor in vitro.2.IGF-I can advance the proliferation and osteogenic phenotype expression of the Fb stimulated by the rhBMP-2.3.IGF-I can advance the osteogenic phenotype expression of the Fb stimulated by the rhBMP-2.