Objectives and Methods

A total of 41 GDM and 40 normal glucose tolerance subjects were recruited. Through detecting the level of Serum vitamin D with electrochemical luminescence and vitamin D receptor (VDR) with Enzyme-linked immunosorbent assay (ELISA) in maternal and cord blood, the expression leves of CYP24A1, CYP27B1, VDR protein and mRNA in placenta and umbilical cord with western blotting and RT-PCR, and the DNA methylation levels of CYP24A1 and CYP27B1 gene in placenta with methylation-specific PCR (MSP) and direct bisulfite sequencing (BSP) analysis to explore the potential role of the vitamin D and its related genes in gestational diabetes mellitus (GDM).

Results

Serum vitamin D concentrations were significantly higher in normal pregnant than women with GDM in maternal blood (P < 0.01) and cord blood (P = 0.014). Compared to the control group, the expression levels of CYP24A1 protein (P < 0.01) and mRNA (P = 0.021) and VDR protein (P = 0.026) and mRNA (P = 0.023) in the GDM group were significantly higher in placenta and umbilical cord tissues (P = 0.015, P < 0.01, P = 0.028, P < 0.01, respectively), while that of CYP27B1 protein (P < 0.01) and mRNA (P = 0.042) was significantly lower (P = 0.022, P = 0.032, respectively). Moreover, partial DNA methylation of CYP24A1 and CYP27B1 genes was observed in both GDM and control groups.

Conclusions

Vitamin D deficiency participates in the pathogenesis of GDM, and changes in the expression of genes related to the vitamin D metabolic pathway are closely related to vitamin D levels in the pregnancy and fetus. However, DNA methylation of CYP24A1 and CYP27B1 might not be involved in the pathogenesis of GDM.

中文翻译：

---

妊娠糖尿病孕妇的胎盘中维生素D和相关基因的表达

目的与方法

总共招募了41名GDM和40名正常葡萄糖耐量受试者。通过与电化学发光和维生素d受体（检测血清维生素d的电平VDR）与母体和脐带血酶联免疫吸附测定（ELISA），表达leves CYP24A1，CYP27B1，VDR蛋白和mRNA在胎盘和脐带蛋白质印迹法和RT-PCR法检测胎盘中CYP24A1和CYP27B1基因的甲基化水平，采用甲基化特异性PCR（MSP）和亚硫酸氢盐直接测序（BSP）分析，探讨维生素D及其相关基因在胎盘中的潜在作用妊娠糖尿病（GDM）。

结果

正常孕妇的血清中维生素D浓度明显高于GDM妇女的母血（P <0.01）和脐带血（P = 0.014）。与对照组相比，GDM组CYP24A1蛋白（P <0.01）和mRNA（P = 0.021），VDR蛋白（P = 0.026）和mRNA（P = 0.022）的表达水平在胎盘和脐带明显升高。脐带组织（分别为P = 0.015，P <0.01，P = 0.028，P <0.01），而CYP27B1蛋白（P <0.01）和mRNA（P = 0.042）则明显降低（P = 0.022，P = 0.032） ， 分别）。此外，在GDM组和对照组中均观察到CYP24A1和CYP27B1基因的部分DNA甲基化。

结论

维生素D缺乏症参与GDM的发病机制，并且与维生素D代谢途径相关的基因表达的变化与孕妇和胎儿中的维生素D水平密切相关。然而，CYP24A1和CYP27B1的DNA甲基化可能不参与GDM的发病机制。