神经递质P物质通过调控转录因子Osterix的表达促进成骨细胞分化

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

目的研究神经递质P物质调控成骨细胞分化的分子途径。方法分离骨髓基质干细胞进行原代及传代培养；分别采用空白对照、P物质、P物质NK1受体拮抗剂、P物质＋P物质NK1受体拮抗剂进行干预，诱导骨髓基质干细胞向成骨细胞分化；传代培养1～2周后，抽提细胞总RNA，用RT-PCR检测分化过程中Osterix基因的表达。检测结果重复3次，采用单因素方差分析检测结果。结果骨髓基质干细胞在生长对数增殖期为4～6d，采用RT-PCR检测发现P物质干预成骨细胞分化，导致成骨细胞分化过程中重要的转录引子Osterix基因表达，与其他各组比较有显著差异（P〈0．05），Osterix基因表达上调，从而刺激前成骨细胞向成骨细胞转化。而P物质＋P物质NK，受体拮抗剂共同干预，Osterix基因表达与空白对照组无显著差异（P〈0．05），说明P物质通过P物质NK，受体对成骨细胞分化进行调控。结论P物质可调控前成骨细胞分化过程中转录因子Osterix基因表达促进其向成骨细胞分化。P物质对Osterix基因表达的调控依赖P物质NK1受体。

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 （P〈 0.05）. Conclusion The up-regulation of Osterix gene expression by SP may stimulate osteoblastic cell differentiation. SP＇s regulation depends on its receptor NK1.