Abstract: Objective To study the dynamic expression profile of fibroblast growth factor 1 (FGF1) and its receptors (FGFRs) during osteogenic and adipogenic differentiation of human bone marrow stromal cells (hBMSCs), and further exploring the role of FGF1 during hBMSCs differentiation. Methods Cells were isolated from human bone marrow by density gradient centrifugation method. hBMSCs in the 3rd passage were induced into osteoblasts and adipocytes, respectively, and followed by staining experiments for identification. The expression of FGF1, FGFRs, and marker genes during osteogenic and adipogenic differentiation, were detected by real-time PCR. Immunofluorescent staining was applied for FGF1 localization of hBMSCs after induced differentiation. Meanwhile, the influence of exogenous FGF1 on osteogenic and adipogenic differentiation was detected by real-time PCR and Oil Red O stainning. Results Osteogenic and adipogenic induced hBMSCs were positively stained by Alizarin Red S and Oil Red O in vitro. The expression status of FGF1 and its receptors showed dynamic variation. Immunofluorescent staining results illustrated that FGF1 was mainly distributed in cytoplasm, and its expression amount increased in nucleus after osteogenic induction for 3 days. The expression of osteopontin increased during osteogenic differentiation in the presence of exogenous FGF1 for 3 days (P＜0.05), and the amount of lipid droplet decreased and the expression of adipogenic marker genes were suppressed during adipogenic differentiation after the introduction of exogenous FGF1 for 7 days (P＜0.01). Conclusions It has been demonstrated that FGF1 could inhibit adipogenic differentiation of hBMSCs, and promotes the expression of OPN, which may further hasten the maturity of osteogenesis.

Key words: Key words: bone marrow mesenchymal stem cell, osteogenic differentiation, adipogenic differentiation, FGF1, FGFRs