Purpose: To investigate the effect of bovine plasma fibronectin (FN) on the proliferation, differentiation and apoptosis of rat osteoblasts in vitro, in order to offer an experimental basis for the clinical application.
Methods: The enzymes digesting method was used to isolate the rat osteoblasts.The activity of the osteoblasts was determined by the percents of reduced Alamar blue. Elisa method was used to measure the activity of alkaline phosphatase (ALP). Flowcytometry (FCM) was used to analyze cell cycle and apoptosis. Western blotting was used to determine the expression of Bcl-2 and Bax protein of osteoblasts affected by FN. Statistical analysis was performed using SPSS 12.0 software package.
Results: FN can stimulate the proliferation of rat osteoblasts, statistically significant difference was detected at dose more than 40μg/mL (P<0.05). The alkaline phosphatase activity of rat osteoblasts also increased, significant difference was detected at dose of 10μg/mL-50μg/mL by dose dependent (P<0.01). FN increased the cell number of S phase,increased proliferation index (PI) and decreased the apoptosis rate(P<0.01) by dose dependent. The protein expression of Bcl-2 increased,while the protein expression of Bax decreased at dose of 30-50μg/mL.
Conclusions: Certain concentration of bovine plasma FN can stimulate the proliferation and differentiation of rat osteoblasts in vitro, increase the cell number of S phase, suppresses apoptosis of osteoblasts.