Objectives: To determine the effect of fibroblast growth factor-21(FGF-21)on the osteogenic differention of human bone mesenchymal stem cells (hBMSCs) exposed to a hyperglycemia condition in vitro.
Methods: hBMSCs were isolated from adult bone marrows, and identified by Alizarin red and oil red O staining. The expressions of immunophenotype were analysed using flow cytometry (CD105, CD90, CD73, CD44).HBMSCs were divided into control group[glucose (Glu) concentration of 5.5 mmol/L], Glu A, B, C groups(Glu 16.5, 25, 40 mmol/L), FGF-21 group (Glu 5.5mmol/ L+ FGF-21 ),Glu B+ FGF-21 group, and Glu B +FGF-21+cell mitogen activated protein kinase (MAPK) blocker (PD98059, SP600125 ,and SB203580) groups. The effect of FGF-21 on the differentiation of hBMSCs was detected using indicators as follows: alkaline phosphatase(ALP)on day 14, mRNA expressions ofALP, osteocalcin(OCN)and Runx2, protein expressions and phosphorylation of extracellular signal regulated kinase (ERK), mitogen-activated protein kinase(P38) and c-Jun N-terminal kinases(JNK) on day 21.
Results: hBMSCs differentiated into osteoblast cells and lipocyte. The hBMSCs were identified by flow cytometry.Compared with control group, significant increases of ALP mRNA, OCN mRNA and Runx2mRNA levels, as well as phosphorylation of ERK, P38 and JNK were observed in Glu A, B, C groups.Compared with Glu B group, ALP, OCN and Runx2 mRNA levels, and phosphorylation of ERK, P38 and JNK were decreased in Glu B+FGF-21 group .Compared with Glu B+FGF-21 group, ALP and Runx2 mRNA levels, and phosphorylation of ERK, JNK and P38 were decreased in Glu B +FGF-21 +MAPK blocker groups.
Conclusions: High glucose could promote the biomineralization of hBMSCs. FGF-21 in high glucose environment could inhibit the osteogenic differentiation of hBMSCs.
Keywords: High glucose; Human bone mesenchymal stem cells; MAPK signaling; Osteogenic differentiation.