Development of detection method for novel calcium- and phosphate- regulating hormone (phosphatonin)

新型钙磷调节激素（磷酸钙）检测方法的开发

基本信息

批准号：
10557096
负责人：
TAKEDA Eiji
金额：
$ 2.56万
依托单位：
The University of Tokushima
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

Inorganic phosphate (phosphate) is an essential nutrient in the processes of glycolysis, gluconeogenesis, energy metabolism and skeletal mineralization. Type II sodium-dependent phosphate transporter (NPT2) expressed on renal brush border membrane (BBM) serves to physiologically and pathophysiologically regulate phosphate homeostasis. In hereditary X-linked hypophosphatemia (XLH), the NPT2 protein content and the related mRNA content is reduced showing also reduced BBM phosphate transport activity. The gene causing XLH was identified as PHEX (phosphate regulating gene with homologies to endopeptidase on the X-chromosome) and a humoral factor (phosphatonin) inhibiting phosphate transport may be responsible for the renal phosphate loss observed in XLH.To test this hypothesis directly, we prepared OK-B2400 cells expressing the luciferase gene containing human NPT2 gene promoter. The findings suggest that the hypophosphatemic factor is a normal regulator of phosphate reabsorption in the ki … More dney, and hence normally present in serum, but which becomes aberrant in XLH.Stanniocalcin (STC) is a calcium- and phosphate-regulating hormone produced by the corpuscles of Stannius in bony fishes. The mammalian homologue of STC has recently been reported (STC 1), which stimulates the phosphate uptake of the kidney. The cloning of a second mammalian stanniocalcin (STC2) from the human osteosarcoma cDNA library was identified in our laboratory. The effect of STC2 on the promoter activity of renal NPT2 was first examined, using the culture medium of STC2-transfected CHO cells. The finding suggested that STC2 would inhibit the expression of a renal NPT2 at the transcriptional level. Furthermore, we established the assay method of STC2 after preparing anti-STC2 antibody. STC2 expression is widely distributed an many organs. STC2 is constitutively excreted from chinese hamster ovary (CHO-K1) cells, but not from opposum kidney cell line (OK-B).However excretion of STC2 from OK-B cell was dramatically stimulated by 1,25 (OH) 2D3 mediated by calcium influx, indicating regulatory excretion of SCT2 from renal tubular cells. Therefore, it is concluded the STC2 will provide another dimension of the regulation of bone and mineral metabolism and a good candidate for the putative phosphatonin. Less

无机磷酸盐（磷酸盐）是糖酵解，糖生成，能量代谢和骨骼疾病的基本营养素。）隆起活性。 NPT2基因启动子。最近有报道说（STC 1）来自人类骨肉瘤cDNA库中的哺乳动物stanniocalcin（STC2）在我们的实验室中确定的STC2对肾脏NPT2的促进性的影响，使用STC2转换的Cho Cho Cho细胞培养基首先检查TTC2会在制备抗体后抑制肾脏NPT2的表达。线（ok-b）。从OK-B细胞中的STC2排泄。由1,25（OH）2d3刺激了由钙涌入介导的2d3，表明SCROT2 LLS的调节性会提供STC2的另一个sTC2。骨骼和矿物质代谢的调节和推定磷酸的良好候选者