Nishikawa Ryuhei, Anada Takahisa, Ishiko-Uzuka Risa, Suzuki Osamu
Division of Craniofacial function Engineering, Tohoku University Graduate School of Dentistry.
Dent Mater J. 2014;33(2):242-51. doi: 10.4012/dmj.2013-226. Epub 2014 Mar 4.
The present study investigated the role of mitogen-activated protein kinase (MAPK) signaling in osteoblastic differentiation of stromal ST-2 cells induced by synthetic octacalcium phosphate (OCP) incubation. Since our previous studies revealed that OCP consumes calcium ions in media during conversion to hydroxyapatite, the effect of the ions on ST-2 cell differentiation with or without OCP crystals was analyzed. The effect of presence or absence of MAPK inhibitors was also analyzed. OCP increased alkaline phosphatase (ALP) activity and the mRNA expression of differentiation markers via the p38 signaling pathway. The PD98059 MAPK inhibitor increased ALP activity and differentiation marker genes in cells cultured in OCP-coated wells. Reduction of calcium ions in the medium by EGTA increased the ALP activity without OCP in the presence of phosphate ion concentrations up to 7.5 mM. OCP may enhance osteoblastic differentiation through the p38 signaling pathway via the reduction of calcium ions induced by its physicochemical property.
本研究调查了丝裂原活化蛋白激酶（MAPK）信号通路在合成磷酸八钙（OCP）孵育诱导的基质ST-2细胞成骨细胞分化中的作用。由于我们之前的研究表明，OCP在转化为羟基磷灰石的过程中会消耗培养基中的钙离子，因此分析了这些离子在有无OCP晶体情况下对ST-2细胞分化的影响。同时也分析了有无MAPK抑制剂的作用。OCP通过p38信号通路增加了碱性磷酸酶（ALP）活性和分化标志物的mRNA表达。PD98059 MAPK抑制剂增加了在OCP包被孔中培养的细胞的ALP活性和分化标志物基因。在磷酸根离子浓度高达7.5 mM的情况下，EGTA降低培养基中的钙离子会增加无OCP时的ALP活性。OCP可能通过其物理化学性质诱导的钙离子减少，经由p38信号通路增强成骨细胞分化。
