Department of Pediatrics, Osaka University Graduate School of Medicine, Suita 565-0871, Japan.
J Clin Endocrinol Metab. 2011 Jun;96(6):E943-7. doi: 10.1210/jc.2010-2357. Epub 2011 Mar 16.
Fetal serum levels of calcium and phosphate are higher than those in the maternal levels. Although α-Klotho is known to participate in calcium and phosphate metabolism in adults, its role in the perinatal period remains unknown.
This study aimed to determine the baseline levels of soluble α-Klotho in fetuses and compare them with those in neonates, mothers, and adults to clarify whether α-Klotho is involved in the fetal-specific regulation of calcium and phosphate metabolism.
We conducted a cross-sectional evaluation of healthy babies (at birth and/or at 4 d after birth), their mothers, and adult volunteers at one hospital.
Twenty-one healthy mothers, their babies (23 in total, including two pairs of twins), and 25 adult volunteers participated in the study.
We measured the serum levels of soluble α-Klotho and fibroblast growth factor 23 (FGF23).
In cord blood, the level of α-Klotho was markedly higher (3243 ± 1899 pg/ml) than levels in neonates at d 4 (582 ± 90 pg/ml), mothers (768 ± 261 pg/ml), and adult volunteers (681 ± 140 pg/ml) (P < 0.001), whereas the fetal level of FGF23 was lower than levels in the other subjects. The levels of soluble α-Klotho were negatively correlated with those of FGF23 in cord blood. Immunohistochemistry demonstrated that α-Klotho was predominantly expressed in syncytiotrophoblasts in normal term placenta.
Levels of soluble α-Klotho are markedly elevated in cord blood and might be useful as a biomarker for mineral metabolism in the fetus.
胎儿血清中的钙和磷水平高于母体水平。虽然 α-Klotho 已知参与成人的钙和磷代谢，但它在围产期的作用尚不清楚。
本研究旨在确定胎儿中可溶性 α-Klotho 的基线水平，并将其与新生儿、母亲和成人进行比较，以明确 α-Klotho 是否参与胎儿特异性钙和磷代谢的调节。
我们在一家医院对健康婴儿（出生时和/或出生后 4 天）、其母亲和成年志愿者进行了横断面评估。
21 位健康的母亲、她们的婴儿（总共 23 位，包括两对双胞胎）和 25 位成年志愿者参与了这项研究。
我们测量了血清中可溶性 α-Klotho 和成纤维细胞生长因子 23（FGF23）的水平。
在脐血中，α-Klotho 的水平明显高于新生儿在第 4 天（582 ± 90 pg/ml）（P < 0.001），低于母亲（768 ± 261 pg/ml）和成年志愿者（681 ± 140 pg/ml）的水平，而胎儿的 FGF23 水平较低。脐血中可溶性 α-Klotho 的水平与 FGF23 的水平呈负相关。免疫组织化学显示，α-Klotho 主要在正常足月胎盘的合体滋养层中表达。
可溶性 α-Klotho 的水平在脐血中明显升高，可能作为胎儿矿物质代谢的有用生物标志物。
