Orthodontics and Craniofacial Developmental Biology, Hiroshima University Graduate School of Biomedical Sciences, Hiroshima 734-8553, Japan.
J Endocrinol. 2010 Sep;206(3):279-86. doi: 10.1677/JOE-10-0058. Epub 2010 Jun 8.
Osteoblasts/osteocytes are the principle sources of fibroblast growth factor 23 (FGF23), a phosphaturic hormone, but the regulation of FGF23 expression during osteoblast development remains uncertain. Because 1alpha,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) and inorganic phosphate (Pi) may act as potent activators of FGF23 expression, we estimated how these molecules regulate FGF23 expression during rat osteoblast development in vitro. 1,25(OH)(2)D(3)-dependent FGF23 production was restricted largely to mature cells in correlation with increased vitamin D receptor (VDR) mRNA levels, in particular, when Pi was present. Pi alone and more so in combination with 1,25(OH)(2)D(3) increased FGF23 production and VDR mRNA expression. Parathyroid hormone, stanniocalcin 1, prostaglandin E(2), FGF2, and foscarnet did not increase FGF23 mRNA expression. Thus, these results suggest that 1,25(OH)(2)D(3) may exert its largest effect on FGF23 expression/production when exposed to high levels of extracellular Pi in osteoblasts/osteocytes.
成骨细胞/骨细胞是成纤维细胞生长因子 23（FGF23）的主要来源，FGF23 是一种磷调节激素，但成骨细胞发育过程中 FGF23 表达的调节仍不确定。由于 1α,25-二羟维生素 D（1,25(OH)(2)D(3)）和无机磷（Pi）可能作为 FGF23 表达的有效激活剂，我们估计这些分子在体外如何调节大鼠成骨细胞发育过程中的 FGF23 表达。1,25(OH)(2)D(3)依赖性 FGF23 产生主要局限于成熟细胞，与维生素 D 受体 (VDR) mRNA 水平增加相关，特别是在存在 Pi 的情况下。Pi 单独存在，尤其是与 1,25(OH)(2)D(3) 联合存在时，增加了 FGF23 的产生和 VDR mRNA 的表达。甲状旁腺激素、1 型 stanniocalcin、前列腺素 E(2)、FGF2 和膦甲酸酯均未增加 FGF23 mRNA 的表达。因此，这些结果表明，当成骨细胞/骨细胞暴露于高浓度细胞外 Pi 时，1,25(OH)(2)D(3) 可能对 FGF23 的表达/产生产生最大影响。
