【作者】 王颖；

【导师】 宋薇薇；

【作者基本信息】 中国医科大学 ， 妇产科学， 2010， 硕士

【摘要】 目的系统研究印记基因PEG1与PEG3在无妊娠并发症的异常出生体重儿胎盘组织中的mRNA表达和启动子区甲基化及其意义。方法应用实时定量PCR技术和基因组DNA亚硫酸氢钠处理后直接测序法检测高出生体重组(出生体重≥4000g,22例)、低出生体重组(出生体重<2500g,14例)和正常出生体重组(2500g≤出生体重<4000g)胎盘组织中PEGl与PEG3的mRNA表达和启动子区甲基化,并分析其与出生体重的关系。结果(1)PEG1与PEG3mRNA表达水平：高出生体重组为11.66±9.01与16.45±10.13,低出生体重组为0.84±0.49与0.85±0.67,正常出生体重组为1.10±0.77与1.11±0.60。两基因高出生体重组与正常出生体重组比较差异均有统计学意义(P＜0.05),低出生体重组与正常出生体重组比较差异均无统计学意义(P＞0.05)；(2)PEG1启动子区甲基化水平：高出生体重组为49.7%±2.3%,低出生体重组为50.2%±2.1%,正常出生体重组为50.3%±1.9%,三组之间比较差异均无明显统计学意义(P＞0.05)；PEG3启动子区甲基化水平：高出生体重组为13.1%±2.7%,低出生体重组为16.7%±3.5%,正常出生体重组为16.2%±1.8%,高出生体重与正常出生体重之间差异有统计学意义(P<0.05),但正常出生体重组与低出生体重组之间无明显统计学意义(P＞0.05);(3)PEG3的mRNA的表达与启动子区甲基化水平之间相关性有统计学意义,呈负相关(R=-0.845；P＜0.01)。结论PEG1和PEG3的表达上调可能是高出生体重产生的原因之一,PEG3的启动子区甲基化水平的降低可能参与其表达上调,并且可能与高出生体重的产生相关。更多还原

【Abstract】 ObjectiveIn this study, we performed a systematic survey of the variation of the imprinted gene Paternally expressed 1 (PEG1) and Paternally expressed gene 3 (PEG3) expression and promoter methylation status in the human abnormal birth weight placentae without any pregnancy-related complications.MethodIn the placenta with high birth weight(birth weight≥4000g), normal birth weight(2500g≤birth weight<4000g) and low birth weight(birth weight<2500g), we have evaluated PEG1 and PEG3 expression levels with real-time reverse-transcriptase polymerase chain reaction (PCR) analysis. Promoter methylation was measured by the bisulfite genomic sequencing method.Results(1) Imprinted gene PEG1 and PEG3 expression:high birth weight(11.66±9.01 and 16.45±10.13), low birth weight(0.84±0.49 and 0.85±0.67) and normal birth weight(1.10±0.77 and 1.11±0.60). Both genes were significantly up-regulated in high birth weight compared to normal birth weight (P<0.05), and there were no significant difference between normal birth weight and low birth weight(P>0.05) about the two genes.(2) PEG1 promoter methylation:high birth weight(0.497±0.023), low birth weight(0.502±0.021) and normal birth weight(0.503±0.019), the level among three groups keep stable(P>0.05). PEG3 promoter methlation:high birth weight(0.131±0.027), low birth weight(0.167±0.035) and normal birth weight(0.162±0.018), the level was down-regulated in high birth weight compared with normal birth weight, but the methylation between low birth weight and normal birth weight was no significant change.(3) We discovered up-regulated expression of PEG3 was accompanied by down-regulated DNA methylation level within objective fragment of promoter region (R=-0.845; P＜0.01).ConclusionThis study showed the two genes up-regulated expression may be a cause of human high birth weight. The reduction of methylation pattern in the promoter region of PEG3 may up-regulate expression and contribute to the mechanism of human high birth weight.更多还原