维生素D及其代谢相关基因与妊娠期糖尿病关系的研究

The Relationship between Vitamin D and Its Metabolic Genes and Gestational Diabetes Mellitu

目的:探讨维生素D(Vit D)及其代谢相关基因与妊娠期糖尿病(GDM)的关系。方法:选择于本院行择期剖宫产的孕晚期单胎GDM孕妇41例为GDM组;另选择同期正常妊娠择期剖宫产单胎孕妇40例为对照组,在手术前采集母血,术中胎儿分娩后留取脐带血和胎盘组织。利用比色法测定空腹血糖(FPG);电化学发光法检测母血、脐血血浆Vit D水平及空腹胰岛素(FINS)水平;ELISA法检测母血、脐血维生素D结合蛋白(VDBP)水平;荧光定量逆转录聚合酶链反应(RT-PCR)和免疫印迹法(WB)测定Vit D代谢相关基因24羟化酶(CYP24A1)、1α羟化酶(CYP27B1)、VDBP mRNA及蛋白在胎盘组织的表达;并对母血、脐血Vit D及其代谢相关基因行相关性分析。结果:(1)GDM组母血Vit D缺乏患者比例(87.8%)显著高于对照组(65.0%),Vit D充足患者的比例(0)明显低于对照组(10.0%),差异有统计学意义(P <0.05)。(2)GDM组母血及脐血的Vit D水平均明显低于对照组(P <0.05);GDM组母血VDBP水平显著高于对照组(P <0.05),而脐血VDBP水平却明显低于对照组(P <0.05)。(3)GDM组与对照组相比,胎盘组织CYP24A1 mRNA及蛋白的表达量均明显升高(P <0.05);CYP27B1、VDBP mRNA及蛋白的表达量降低(P <0.05)。(4)母血Vit D水平在两组中均与FINS、胰岛素抵抗指数(HOMA-IR)、胎盘组织CYP24A1蛋白的表达呈负相关(r <0,P <0.05),而与脐血Vit D及胎盘组织CYP27B1蛋白的表达呈正相关(r> 0,P <0.05);母血Vit D水平与胎盘组织VDBP mRNA及蛋白在GDM组呈正相关(r> 0,P <0.05)。结论:维生素D缺乏可能通过减少胰岛素的分泌和增加胰岛素抵抗参与GDM的发病。GDM孕妇胎盘组织Vit D分解基因(CYP24A1)表达的增加和合成基因(CYP27B1)及VDBP表达的降低可能是母血Vit D和脐血Vit D水平较低的原因。

Objective: To explore the relationship between vitamin D( Vit D)-related genes and the clinical characteristics of gestational diabetes mellitus( GDM). Methods: A total of 41 pregnant female patients with singleton and diagnosed as GDM who underwent elective cesarean section in our hospital were included as GDM group,and 40 normal pregnant female patients with no GDM diagnosis were included as control group( NGT group).Preoperative blood sample and umbilical cord blood sample were collected,and placental tissue were also collected after delivery. The leves of fasting blood glucose( FPG) were measured by colorimetry,the levels of Vit D insulin( FINS) in maternal blood and umbilical cord blood were measured by electrochemilum inessence. The relative expressions of Vit D metabolism related genes CYP24A1,CYP27B1,VDBPmRNA and protein in placenta were detected by fluorescence quantitative reverse transcriptase polymerase chain reaction( FQRT-PCR) and Western blotting( WB) respectively. Pearson method was applied to analyze the correlation between the Vit D level of blood sample and Vit D metabolism related genes. Results:(1)The proportion of patients with maternal Vit D deficiency in GDM group( 87. 8%) was significantly higher than that in NGT group( 65. 0%),while the proportion of patients with adequate vitamin D was significantly lower than that in control group( 0 vs. 10. 0%)( P < 0. 05).(2)The levels of plasma Vit D in maternal blood and umbilical cord blood in GDM group were significantly lower than those in control group( P < 0. 05),while the level of maternal blood VDBP in GDM group was significantly higher than that in control group( P < 0. 05),but the level of VDBP in umbilical cord blood was significantly lower than that in control group( P < 0. 05).(3)Compared with NGT group,the expression of CYP24A1 mRNA and protein in placenta of GDM group increased significantly,while the expression of CYP27B1,VDBP mRNA and protein decreased( P <0. 05).(4)The level of maternal blood Vit D was negatively correlated with FINS,HOMA-IR and CYP24A1 protein expression in placenta( r < 0,P < 0. 05). It was positively correlated with the expression of Vit D in cord blood and CYP27B1 in placenta( r > 0,P < 0. 05). It was positively correlated with VDBP mRNA and protein in placental tissue in GDM group( r > 0,P < 0. 05). Conclusions: Vitamin D deficiency may participate in the pathogenesis of GDM by reducing insulin secretion and increasing insulin resistance. The increased expression of Vit D decomposition gene( CYP24A1),accompany with the decreased expression of synthetic gene( CYP27B1) and VDBP in placenta of pregnant female patients with GDM may lead to a lower level of Vit D in maternal blood and umbilical cord blood.