Thyrocalcitonin regulates the cbfa1mRNA expression of osteoblasts via signal pathway of ERK-MAPK

Objective To observe the effect of thyrocalcitonin on the cbfa1mRNA expression of osteoblasts and the effect of ERK-MAPK in the above process.Methods Isolate the osteoblasts from craniums of neonate rats within 24 hours after its birth and culture the osteoblasts in vitro.The second generation osteoblasts were co cultured with thyrocalcitonin at different concentrations: blank group,0.01 ng/mL calcitonin group,0.1 ng/mL calcitonin group,1 ng/mL calcitonin group,and another 1 ng/mL calcitonin group were added with U0126,a specific inhibitor of ERK-MAPK,in advance.The level of cbfa1mRNA in different groups were measured by RT-PCR and the phos-ERK1/2 expression of OB was analyzed by western blotting.Results Calcitonin can improve the expression of cbfa1 mRNA in dose-dependent manner.The effect of the 0.1 ng/mL calcitionin group and the 1 ng/mL calcitonin group had significant effects(P0.01);The expression of the phospho-ERK1/2 was also related to the calcitionin concentration.Moreover,all the effects above were blocked by U0126.Conclusion Calcitonin improves the expression of cbfa1mRNA via the signal pathway of ERK-MAPK.