妊娠期糖尿病孕妇PGC-1α基因甲基化水平与胎儿宫内窘迫的相关性研究

Study on the correlation between methylation level of PGC-1α gene and fetal distress in pregnant women with gestational diabetes mellitus

目的检测妊娠期糖尿病(gestational diabetes mellitus,GDM)孕妇胎盘组织过氧化物酶体增生物激活受体γ共激活因子1α(PGC-1α)基因甲基化水平及mRNA表达水平,并探讨二者与胎儿宫内窘迫的关系。方法选取2018年7月至2019年12月烟台市烟台山医院产科收治的174例GDM孕妇为研究对象,其中胎儿出现宫内窘迫的78名孕妇作为胎儿宫内窘迫组;胎儿正常出生未出现宫内窘迫的96例孕妇为对照组;另同期选取82名无GDM正常妊娠孕妇作为健康组。亚硫酸氢钠处理DNA后采用直接测序法检测胎盘组织中PGC-1α基因甲基化水平;实时荧光定量PCR(qRT-PCR)法检测胎盘组织中PGC-1αmRNA表达水平;全自动生化分析仪检测甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)水平;分析胎儿发生宫内窘迫孕妇PGC-1α基因甲基化频率与PGC-1αmRNA表达水平的相关性;分析影响胎儿宫内窘迫发生的因素。结果胎儿宫内窘迫组PGC-1α基因甲基化频率及TG水平[(25.42±7.31)%、(4.72±0.68)mmol/L]高于对照组[(9.26±2.67)%、(4.31±0.64)mmol/L]和健康组[(3.24±1.07)%、(4.33±0.72)mmol/L],对照组PGC-1α基因甲基化频率高于健康组,差异均有统计学意义(P<0.05);胎儿宫内窘迫组PGC-1αmRNA表达水平(0.67±0.16)低于对照组(0.74±0.14)和健康组(1.00±0.27),对照组PGC-1αmRNA表达水平低于健康组,差异均有统计学意义(P<0.05);胎儿发生宫内窘迫孕妇PGC-1α基因甲基化频率与PGC-1αmRNA表达水平呈负相关(r=-0.515、P<0.05);PGC-1α基因甲基化是影响胎儿发生宫内窘迫的独立危险因素(P<0.05),PGC-1αmRNA高表达是胎儿发生宫内窘迫的保护因素(P<0.05)。结论GDM孕妇PGC-1α基因DNA甲基化水平与胎儿宫内窘迫相关,有可能作为胎儿宫内窘迫的基因修饰靶点。

Objective To detect the methylation level and mRNA expression level of peroxisome proliferator activated receptory-coactivator-1α(PGC-1α)gene in placental tissue of pregnant women with gestational diabetes(GDM)and to explore the relationship between them and fetal distress.Methods A total of 174 pregnant women with GDM admitted to in our hospital from Jul.2018 to Dec.2019 were selected as the study objects,among which 78 pregnant women with fetal distress were selected as the fetal distress group;and 96 pregnant women with normal delivery and without fetal distress were the control group;during the same period,82 normal pregnant women without GDM were selected as the healthy group.The methylation level of PGC-1αgene in placenta was detected by direct sequencing after DNA was treated with sodium bisulfite;the expression of PGC-1αmRNA in placenta was detected by real-time fluorescence quantitative PCR(qRT-PCR);the levels of triglyceride(TG),total cholesterol(TC),low density lipoprotein cholesterol(LDL-C)and high density lipoprotein cholesterol(HDL-C)were measured by automatic biochemical analyzer;the relationship between methylation frequency of PGC-1αgene and the expression level of PGC-1αmRNA was analyzed;and the influencing factors of fetal distress were analyzed.Results PGC-1αgene methylation frequency and TG level were higher in the fetal distress group[(25.42±7.31)%,(4.72±0.68)mmol/L]than in the control group[(9.26±2.67)%,(4.31±0.64)mmol/L]and the healthy group[(3.24±1.07)%,(4.33±0.72)mmol/L].PGC-1αgene methylation frequency was higher in the control group than in the healthy group,and the differences were statistically significant(P<0.05);PGC-1αmRNA expression level in fetal distress group(0.67±0.16)is lower than that in the control group(0.74±0.14)and healthy group(1.00±0.27).PGC-1αmRNA expression level in control group was lower than that in healthy group,and the difference was statistically significant(P<0.05);the methylation frequency of PGC-1αgene was negatively correlated with the expression level of PGC-1αmRNA in pregnant women with fetal distress(r=-0.515,P<0.05);the methylation of PGC-1αgene was an independent risk factor for fetal distress(P<0.05),and the high expression of PGC-1αmRNA was the protective factor of fetal distress(P<0.05).Conclusion DNA methylation level of PGC-1αgene in pregnant women with GDM is related to fetal distress,which may be the target of gene modification for fetal distress.