Cleal J K, Day P E, Simner C L, Barton S J, Mahon P A, Inskip H M, Godfrey K M, Hanson M A, Cooper C, Lewis R M, Harvey N C
Faculty of Medicine, Institute of Developmental Sciences, University of Southampton,Tremona Road,SouthamptonSO16 6YD,UK.
MRC Lifecourse Epidemiology Unit, University of Southampton,Tremona Road,SouthamptonSO16 6YD,UK.
Br J Nutr. 2015 Jun 28;113(12):1903-10. doi: 10.1017/S0007114515001178. Epub 2015 May 5.
Both maternal 25-hydroxyvitamin D (25(OH)D) concentrations during pregnancy and placental amino acid transporter gene expression have been associated with development of the offspring in terms of body composition and bone structure. Several amino acid transporter genes have vitamin D response elements in their promoters suggesting the possible linkage of these two mechanisms. We aimed to establish whether maternal 25(OH)D and vitamin D-binding protein (VDBP) levels relate to expression of placental amino acid transporters. RNA was extracted from 102 placental samples collected in the Southampton Women's Survey, and gene expression was analysed using quantitative real-time PCR. Gene expression data were normalised to the geometric mean of three housekeeping genes, and related to maternal factors and childhood body composition. Maternal serum 25(OH)D and VDBP levels were measured by radioimmunoassay. Maternal 25(OH)D and VDBP levels were positively associated with placental expression of specific genes involved in amino acid transport. Maternal 25(OH)D and VDBP concentrations were correlated with the expression of specific placental amino acid transporters, and thus may be involved in the regulation of amino acid transfer to the fetus. The positive correlation of VDBP levels and placental transporter expression suggests that delivery of vitamin D to the placenta may be important. This exploratory study identifies placental amino acid transporters which may be altered in response to modifiable maternal factors and provides a basis for further studies.
孕期母体25-羟基维生素D(25(OH)D)浓度和胎盘氨基酸转运蛋白基因表达均与后代的身体组成和骨骼结构发育有关。几种氨基酸转运蛋白基因的启动子中存在维生素D反应元件,提示这两种机制可能存在联系。我们旨在确定母体25(OH)D和维生素D结合蛋白(VDBP)水平是否与胎盘氨基酸转运蛋白的表达有关。从南安普顿妇女调查中收集的102份胎盘样本中提取RNA,并使用定量实时PCR分析基因表达。基因表达数据以三个管家基因的几何平均值进行标准化,并与母体因素和儿童身体组成相关。通过放射免疫测定法测量母体血清25(OH)D和VDBP水平。母体25(OH)D和VDBP水平与参与氨基酸转运的特定基因的胎盘表达呈正相关。母体25(OH)D和VDBP浓度与特定胎盘氨基酸转运蛋白的表达相关,因此可能参与调节氨基酸向胎儿的转运。VDBP水平与胎盘转运蛋白表达的正相关表明维生素D向胎盘的输送可能很重要。这项探索性研究确定了可能因可改变的母体因素而发生改变的胎盘氨基酸转运蛋白,并为进一步研究提供了基础。