title: Up-regulation of stanniocalcin 1 expression by 1,25-dihydroxy vitamin D(3) and parathyroid hormone in renal proximal tubular cells.
abstract: Stanniocalcin 1 and stanniocalcin 2 are two glycoprotein hormones, which act as calcium phosphate-regulating factor on intestine and kidney. We have previously reported that stanniocalcin 2 expression is positively and negatively controlled by 1,25(OH)(2)D(3) and parathyroid hormone in renal proximal tubular cells. However, it has been unclear whether they regulate the stanniocalcin 1 gene expression. In this study, we identified the opossum stanniocalcin 1 cDNA sequence. The opossum stanniocalcin 1 amino acid sequence had 83% homology with human stanniocalcin 1, and has a conserved putative N-linked glycosylation site. Real-time PCR analysis using opossum kidney proximal tubular (OK-P) cells revealed that the mRNA levels of stanniocalcin 1 gene is up-regulated by both 1,25(OH)(2)D(3) and parathyroid hormone in dose-dependent and time-dependent manners. We also demonstrated that the stanniocalcin 1 expression was increased in parathyroid hormone injected rat kidney. Furthermore, the mRNA expression of stanniocalcin 1 and stanniocalcin 2 were oppositely regulated by phorbol 12,13-myristic acetate, a specific PKC activator. Interestingly, the up-regulation of stanniocalcin 1 gene by 1,25(OH)(2)D(3) and phorbol 12,13-myristic acetate were not prevented in the presence of actinomycin D, an RNA synthesis inhibitor. These results suggest that the stanniocalcin 1 gene expression is up-regulated by 1,25(OH)(2)D(3) and parathyroid hormone through mRNA stabilization in renal proximal tubular cells.
authors.affiliation: Department of Clinical Nutrition, Institute of Health Biosciences, University of Tokushima Graduate School, Kuramoto-Cho 3-18-15, Tokushima 770-8503, Japan.
authors.forename: Nguyen Trong
authors.initials: NT
authors.lastname: Hung
authors.forename: Hironori
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Takei
authors.forename: Masashi
authors.initials: M
authors.lastname: Masuda
authors.forename: Ayako
authors.initials: A
authors.lastname: Otani
authors.forename: Mina
authors.initials: M
authors.lastname: Kozai
authors.forename: Shoko
authors.initials: S
authors.lastname: Ikeda
authors.forename: Otoki
authors.initials: O
authors.lastname: Nakahashi
authors.forename: Sarasa
authors.initials: S
authors.lastname: Tanaka
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Taketani
authors.forename: Eiji
authors.initials: E
authors.lastname: Takeda