Hatakeyama Yuji, Hatakeyama Junko, Takahashi Atsushi, Oka Kyoko, Tsuruga Eichi, Inai Tetsuichiro, Sawa Yoshihiko
Department of Morphological Biology, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka 814-0193, Japan.
Drug Target Insights. 2011;5:1-9. doi: 10.4137/DTI.S6534. Epub 2011 Mar 22.
Valproic acid (2-n-propylpentanoic acid, VPA) is a widely used antiepileptic and anticonvulsant drug. Previous studies have reported that VPA effects osteogenesis in vivo and in vitro, yet it remains unclear whether VPA promotes cell differentiation of osteoblasts derived from mesenchymal cells. The purpose of this study was to clarify the effect of VPA on undifferentiated pluripotent mesenchymal cell proliferation and differentiation into osteoblasts while analyzing the impact of the absence or presence of extracellular matrices (ECMs). Mouse mesenchymal cells were cultured on non-coated plastic, type I collagen-coated, and fibronectin-coated plates in the absence or presence of VPA. A cell proliferation assay was performed in which modified formazan dye content was analyzed and proliferation nuclear antigen (PCNA)-positive cells were counted at various concentrations of VPA. A high concentration of VPA did not clearly alter cell morphology, but large numbers of stress fibers were observed in these cells and the cell proliferation ratio was decreased with positive PCNA counts. In the presence of matrices, the cell proliferation ratio decreased at low VPA concentrations compared with the ratio obtained in the absence of these ECMs. On the other hand, VPA promoted osteoblastic differentiation in the presence of type I collagen. These findings indicate that for undifferentiated mesenchymal cells, VPA promotes a decrease in the cell proliferation rate in the presence of ECMs and promotes osteoblastic differentiation, both of which could provide insight into additional mechanisms of osteoblastic cell differentiation caused by VPA.
丙戊酸（2-正丙基戊酸，VPA）是一种广泛使用的抗癫痫和抗惊厥药物。先前的研究报道，VPA在体内和体外均对骨生成有影响，但VPA是否促进间充质来源的成骨细胞的细胞分化仍不清楚。本研究的目的是在分析细胞外基质（ECM）存在与否的影响的同时，阐明VPA对未分化的多能间充质细胞增殖以及向成骨细胞分化的作用。在有无VPA的情况下，将小鼠间充质细胞接种于未包被的塑料板、I型胶原包被的板和纤连蛋白包被的板上进行培养。进行细胞增殖试验，分析不同浓度VPA下改良甲臜染料含量并计数增殖细胞核抗原（PCNA）阳性细胞。高浓度VPA并未明显改变细胞形态，但在这些细胞中观察到大量应力纤维，且细胞增殖率随PCNA阳性计数而降低。在有基质存在的情况下，与无这些ECM时相比，低浓度VPA时细胞增殖率降低。另一方面，在I型胶原存在的情况下，VPA促进成骨细胞分化。这些发现表明，对于未分化的间充质细胞，VPA在有ECM存在时促进细胞增殖率降低并促进成骨细胞分化，这两者都可为VPA引起的成骨细胞分化的其他机制提供见解。
