Effect of fibroblast growth factor receptor 2 on osteogenic differentiation of mouse bone marrow mesenchymal stem cells

Abstract

Objective To observe the effect of fibroblast growth factor receptor 2 (FGFR2) on the ability of bone marrow mesenchymal stem cells (BMSCs) to differentiate into osteoblasts. Methods The FGFR2 gene of mouse BMSCs was overexpressed, and the proliferation ability at 24, 48 and 72 h was measured by methyl thiazol tetrazolium (MTT) assay. After the FGFR2 gene was overexpressed, the osteogenic differentiation and mineralization ability of the cells was examined by alizarin red staining and alkaline phosphatase (ALP) staining, and Western blotting was used to detect the expression of osteocalcin (OCN), osteopontin (OPN), runt related transcription factor-2 (Runx2), ALP and bone morphogenetic protein-2 (BMP-2) protein related genes of osteogenic differentiation after 14 days of osteogenesis induced differentiation. A mouse model of castrated osteoporosis was established, and the effect of up-regulation of FGFR2 on osteoporosis in mice was studied. The number of bone trabeculae and bone volume fraction were evaluated by mircoCT. Results The proliferation of BMSCs at 24, 48 and 72 h was promoted after up-regulation of FGFR2. The number of calcium nodules in BMSCs (95.7±8.9) in the FGFR2-up-regulated group was significantly greater than that in the control group (26.4±3.9). The results of ALP staining showed that the osteogenic differentiation ability in the FGFR2-up-regulated group was stronger than that in the control group. The quantitative analysis of ALP activity showed that the ALP activity in the FGFR2-up-regulated group [(6.33±1.33) U/L]was significantly stronger than that in the control group [(2.54±0.75) U/L]. The expression levels of OCN, OPN, UNX2, ALP and BMP-2 proteins in the FGFR2-up-regulated group were higher than those in the control group. The trabecular number (Tb.N) of bone trabecula in the FGFR2 up-regulated group [(2.37±0.26)/mm]was greater than that in the control group [(1.54±0.34)/mm], and the tibial bone volume fraction (BV/TV) in the FGFR2-up-regulated group [(9.97±1.77)%] was higher than that in the control group [(5.91±0.98)%]. Conclusion Upregulation of FGFR2 can promote the proliferation and osteogenic differentiation of mouse BMSCs, which may promote the recovery of osteoporosis. Key words: Fibroblast growth factor receptor 2; Bone marrow mesenchymal stem cells; Osteogenic differentiation; Osteoporosis