title: Comprehensive analysis of DNA methylation and gene expression of placental tissue in preeclampsia patients.
abstract: OBJECTIVE
  DNA methylation is an important epigenetic regulator of gene transcription, and is involved in many diseases, which has been researched recently. In this study, we aimed to investigate DNA methylation and gene expression in preeclampsia placenta. Preeclampsia has been observed in patients with molar pregnancy where a fetus is absent, which demonstrates that the placenta is sufficient to cause this condition.
  
  
  METHODS
  DNA methylation profiles and mRNA expression profiles were compared between two groups, six preeclampsia placentas and six normal pregnancy placentas using microarrays.
  
  
  RESULTS
  The number of promoters with altered DNA methylation was 1664. The number of mRNA identified as differentially expressed between the two groups of placenta samples were 1446. And the number of matched genes with a typical relationship between DNA methylation and gene expression was 42 hypomethylated DNA with increased mRNA expression and 19 hypermethylated DNA with decreased mRNA expression. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and GO analysis were constructed based on the correlation between the differentially expressed DNA methylation and mRNAs.
  
  
  CONCLUSIONS
  Our study is the first study to determine the genome-wide DNA methylation patterns in preeclampsia placenta using microarrays. The results revealed that clusters of DNA methylation were aberrantly altered in preeclampsia placenta compared with controls, which indicated misregulation of DNA methylation.
authors.affiliation: a Center of Assisted Reproduction, The First Affiliated Hospital of Nanchang University , Nanchang , Jiangxi , China.
authors.forename: Jin
authors.initials: J
authors.lastname: Xuan
authors.affiliation: a Center of Assisted Reproduction, The First Affiliated Hospital of Nanchang University , Nanchang , Jiangxi , China.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Jing
authors.affiliation: b Department of Obstetrics and Gynecology , The First Affiliated Hospital of Nanchang University , Nanchang , Jiangxi , China.
authors.forename: Zhu
authors.initials: Z
authors.lastname: Yuanfang
authors.affiliation: c Department of Obstetrics , Jiangxi Maternal and Child Health Hospital , Nanchang , Jiangxi , China.
authors.forename: He
authors.initials: H
authors.lastname: Xiaoju
authors.affiliation: a Center of Assisted Reproduction, The First Affiliated Hospital of Nanchang University , Nanchang , Jiangxi , China.
authors.forename: Li
authors.initials: L
authors.lastname: Pei
authors.affiliation: b Department of Obstetrics and Gynecology , The First Affiliated Hospital of Nanchang University , Nanchang , Jiangxi , China.
authors.forename: Jin
authors.initials: J
authors.lastname: Guiyin
authors.affiliation: d Department of Surgery , The First Affiliated Hospital of Nanchang University , Nanchang , Jiangxi , China.
authors.forename: Zeng
authors.initials: Z
authors.lastname: Yu
mesh_terms: D000328:Adult; D019175:DNA Methylation; D005260:Female; D015870:Gene Expression; D006801:Humans; D010920:Placenta / Q000378:metabolism*; D011225:Pre-Eclampsia / Q000235:genetics* / Q000378:metabolism; D011247:Pregnancy; D011401:Promoter Regions, Genetic
keywords: DNA methylation; mRNA; placenta; preeclampsia; pregnancy