子痫前期患者胎盘组织PHLDA2基因印迹初步研究

Placental PHLDA2 Gene Imprinting in Patients with Pre-eclampsia

中文关键词:  基因印迹 杂合子 印迹状态 子痫前期胎盘 PHLDA2

英文关键词:Gene imprinting Heterozygotes Imprinting status Pre-eclampsia placenta PHLDA2

中文摘要:

      目的 观察子痫前期患者胎盘组织母源性印迹基因PHLDA2印迹状态。方法 收集21例正常妊娠和19例子痫前期患者胎盘组织，抽提样本DNA，PCR扩增，选择PHLDA2基因组变异比例较高的单核苷酸多态性（SNP）位点：rs13390为外显子1中C/T多态性(PHLDA2-1)，rs1056819为外显子2中G/A多态性(PHLDA2-2)，直接测序筛选杂合子。将杂合子样本的RNA逆转录合成cDNA，PCR扩增直接测序判断PHLDA2基因印迹状态。结果 正常妊娠与子痫前期胎盘PHLDA2-1（外显子1）SNP位点(C/T)均未发现杂合子，全为T/T纯合子；胎盘PHLDA2-2（外显子2）SNP位点（G/A）在子痫前期有4例（4/19）、正常妊娠有5例（5/21）杂合子表达，两组杂合子表达差异无统计学意义（P>0.05）。PHLDA2-2杂合子胎盘组织PHLDA2cDNA均只表达G单等位基因。结论 子痫前期胎盘PHLDA2（PHLDA2-1及PHLDA2-2）基因多态性与正常妊娠相似，未发现PHLDA2 基因印迹丢失现象。

英文摘要:

      Objective To observe the imprinting status of maternally expressed gene pleckstrin homology-like domain, family A, member 2 (PHLDA2) in placental tissues from patients with pre-eclampsia. Methods Samples of placental tissues were collected from women with normal pregnancy (n=21) and pre-eclampsia (n=19). We examined two single nucleotide polymorphism (SNPs) which are prone to variation in PHLDA2: the C/T polymorphism in exon 1 and the G/A polymorphism in exon 2, corresponding to rs13390 (PHLDA2-1) and rs1056819 (PHLDA2-2), respectively. DNA PCR-direct sequencing and cDNA RT-PCR-direct sequencing were applied to detect the special-allelic imprinting status of PHLDA2. Results No heterozygote was found in placental tissues in relation to C/T polymorphism in PHLDA2exon 1.Differences in heterozygote in relation to G/A polymorphism in PHLDA2 exon 2 were found betweenpre-eclampsia(4/19) and normal pregnancy(5/21), but without statistical significance. PHLDA2 cDNA from heterozygotes (PHLDA2-2) were all exclusively monoallelically expressed. Conclusion Similargene polymorphism of PHLDA2 (PHLDA2-1 and PHLDA2-2) in placental tissues was found between pre-eclampsiaand normal pregnancies.No loss of imprinting (LOI) of PHLDA2 was found in this study.