Substance P stimulates differentiation of mice osteoblast through up-regulating the expression of Osterix

Objective To study the molecular pathway of osteoblastic differentiation induced by substance P(SP),a neurotransmitter.Methods Mesenchymal stem cells were isolated and cultured,and treated with SP or its receptor(NK1) antagonist to induce osteoblastic cell differentiation,respectively.Alkaline phosphatase activity was determined;Osterix gene expression was detected by RT-PCR after 1-2 weeks for three times.The data of each culture condition were analyzed using SPSS12.0 statistical software to determine whether the differences between conditions were significant.Results After 4-5 days' culture,bone marrow stromal cells became spindle-shaped,triangular or polygonic.They covered the plate surface,formed extensive cell sheets in each group after 11-12 days of culture,and then induced differentiation to osteoblast.SP up-regulated the important transcription factor Osterix gene expression significantly(P0.05).Conclusion The up-regulation of Osterix gene expression by SP may stimulate osteoblastic cell differentiation.SP's regulation depends on its receptor NK1.