BACKGROUND:Calcitonin gene-related peptide has been confirmed to induce osteogenic differentiation, but whether it can induce the osteogenic differentiation of adipose-derived stem cells under three-dimensional culture to construct tissue-engineered bone is rarely reported.
OBJECTIVE:To investigate the feasibility of exogenous calcitonin gene-related peptide to induce osteogenic differentiation of adipose-derived stem cells combined with calcium alginate gel in three-dimensional condition.
METHODS:Adipose-derived stem cells were gained by col agenase I digestion of the subcutaneous adipose tissue of both inguinal regions of New Zealand rabbits. Passage 3 cells were mixed with sodium alginate to prepare calcium alginate gel, and then the cells were assigned into two groups and cultured in 24-wel plates. Adipose-derived stem cells in the control group were cultured in Dulbecco’s modified Eagle’s medium/Ham’s nutrient mixture F-12 supplemented with 10-2 mol/Lβ-glycerophosphate sodium, 10-7 mol/L dexamethasone, 50 mg/L ascorbic acid, 10%fetal bovine serum. While, adipose-derived stem cells in the experimental group were incubated with the same medium as above, but 1.5 μg/L calcitonin gene-related peptide was added. The cells proliferation and the mRNA expressions of col agen I and osteocalcin were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and reverse transcription-PCR respectively, and alkaline phosphatase and calcium concentration were detected at different induction time.
RESULTS AND CONCLUSION:The cellproliferation curves were S shaped. The absorbance values of the experimental group were higher than those of the control group at1, 3, 5, 7, 14, 21 days after osteogenic induction (P<0.05). Alkaline phosphatase and alizarin red staining of adipose-derived stem cells was al positive, but golden round nodes became more and bigger in the experimental group compared with the control group after 2 weeks. At 7 and 14 days, col agen I and osteocalcin mRNA expressions were higher in the experimental group than in the control group. Alkaline phosphatase activity and calcium concentration of the experimental group were higher than those of the control group at 1, 2, 3, 4 weeks after osteogenic induction (P<0.05). Results showed that the calcitonin gene-related peptide can induce the osteogenic differentiation of adipose-derived stem cells combined with calcium alginate gel.