Objective: To investigate the modulating effect of bFGF on the proliferation of human cutaneous fibroblasts and on the activity of human alpha1 (I) procollagen gene promoter.
Methods: Human cutaneous fibroblasts were cultured and subcultured by tissue block culture technique. The influence of different concentrations of bFGF on the proliferation of fibroblasts was determined by ELISA method with BrdU incorporated into fibroblast DNA. Three plasmids containing various lengths of 5prime prime or minute flank sequences of human alpha1 (I) procollagen gene and CAT as reporter gene were constructed and transfected into the fibroblasts by FuGENE transfection reagent. The quantitative expression of the fibroblast CAT was determined by ELISA after treatment with bFGF.
Results: After 24 hours of treatment of the fibroblasts by serial concentrations (0.25 ng/ml similar 64.00 ng/ml) of bFGF in DMEM containing 2% (v/v) or 10% (v/v) FCS, the BrdU incorporation into DNA was determined. The proliferating rate of the fibroblasts differed significantly from each other in all the groups (P < 0.05). After the fibroblasts were transfected with the three plasmids and treated thereafter by 4 ng/ml and 16 ng/ml of bFGF for 24 hours, the relative CAT expression values were determined. It indicated that the expression value was evidently different between bFGF processing and control groups (P < 0.05).
Conclusion: bFGF might inhibit the proliferation of human cutaneous fibroblasts and exert negative regulating effect on the human alpha1 (I) procollagen gene promoter sequence in dose -- dependent pattern.