title: [Variation of long-chain 3-hydroxyacyl-CoA dehydrogenase DNA methylation in placenta of different preeclampsia-like mouse models].
abstract: OBJECTIVE
  By detecting the variation of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) DNA methylation in preeclampsia-like mouse models generated by different ways, to explore the roles of multifactor and multiple pathways in preeclampsia pathogenesis on molecular basis.
  
  
  METHODS
  Established preeclampsia-like mouse models in different ways and divided into groups as follows: (1) Nw-nitro-L-arginine-methyl ester (L-NAME) group: wild-type pregnant mouse received subcutaneous injection of L-NAME; (2) lipopolysaccharide (LPS) group: wild-type pregnant mouse received intraperitoneal injection of LPS; (3) apolipoprotein C-III (ApoC3) group: ApoC3 transgenic pregnant mouse with dysregulated lipid metabolism received subcutaneous injection of L-NAME; (4) β2 glycoprotein I (β-2GPI) group: wild-type pregnant mouse received subcutaneous injection of β-2GPI. According to the first injection time (on day 3, 11, 16 respectively), the L-NAME, LPS and ApoC3 groups were further subdivided into: pre-implantation (PI) experimental stage, early gestation (EG) experimental stage, and late gestation (LG) experimental stage. β-2GPI group was only injected before implantation. LCHAD gene methylation levels in placental were detected in different experimental stage. Normal saline control groups were set within wild-type and ApoC3 transgenic pregnant mice simultaneously.
  
  
  RESULTS
  (1) CG sites in LCHAD DNA: 45 CG sites were detected in the range of 728 bp before LCHAD gene transcription start site, the 5, 12, 13, 14, 15, 16, 19, 24, 25, 27, 28, 29, 30, 31, 32, 34, 35, 43 CG sites were complex sites which contained two or more CG sequences, others were single site which contained one CG sequence. The 3, 5, 6, 11, 13, 14, 18, 28 sites in L-NAME, LPS, ApoC3 and β-2GPI groups showed different high levels of methylation; the 16, 25, 31, 42, 44 sites showed different low levels of methylation; other 32 sites were unmethylated. (2) Comparison of LCHAD gene methylation between different groups: the methylation levels of LCAHD gene at 3, 11, 13, 14, 18 sites in L-NAME, LPS, ApoC3 and β-2GPI groups were significantly higher than those in the normal saline control group (P < 0.05); and the methylation levels of 42, 44 sites in these groups were significantly lower than those in the normal saline control group (P < 0.05). (3) Methylation of LCHAD gene at the same site between different experimental stages: ① The 3, 11, 18 sites of EG experimental stage was significantly lower than PI and LG experimental stage in L-NAME group (P < 0.05); the 3, 11, 18 sites of PI experimental stage was significantly lower than EG and LG experimental stage in LPS group (P < 0.05); these sites of PI experimental stage was significantly higher than EG and LG experimental stages in ApoC3 group (P < 0.05). ② The methylation of site 5 in L-NAME and LPS groups were significantly higher than that of the normal saline control group (P < 0.05), and the LG experimental stages were significantly higher than other stages, but in ApoC3 group, only PI and EG stages were significantly higher than the normal saline control group (P < 0.05). ③ At site 6 in L-NAME group which showed high methylation level was significantly higher than the same site in other groups which showed low methylation level (P < 0.05). ④ At 13, 14 sites, earlier preeclampsia onset caused a lower methylation level in L-NAME group, but PI experimental stage was significantly higher than EG and LG experimental stages in LPS group (P < 0.05), EG experimental stage was significantly higher than PI and LG experimental stages in ApoC3 group (P < 0.05). ⑤ At site 28, earlier preeclampsia onset caused a higher methylation level in L-NAME group, but PI experimental stage was significantly lower than EG and LG experimental stages in LPS group (P < 0.05), EG experimental stage was significantly higher than PI and LG experimental stages in ApoC3 group (P < 0.05). ⑥ The 16, 25, 31 sites in ApoC3 group were significantly higher than other groups (P < 0.05). ⑦ At site 42 in β-2GPI group was unmethylated, but it in other groups showed low methylation level, the methylation level of site 42 in β-2GPI group was significantly lower than that in other groups (P < 0.05).
  
  
  CONCLUSIONS
  The methylation of 6 and 42 CG sites may be related to LCHAD gene expression in placenta of L-NAME and β-2GPI induced preeclampsia-like models respectively; LCHAD gene expression and DNA methylation may not have obvious correlation in LPS and ApoC3 induced preeclampsia-like models. Differences exist in LCHAD DNA methylation in preeclampsia-like models generated by different ways, revealed a molecular basis to expand our understanding of the multi-factorial pathogenesis of preeclampsia.
authors.affiliation: Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Yiwei
authors.initials: Y
authors.lastname: Han
authors.affiliation: Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing 100191, China; Email: zi_yang2005@126.com.
authors.forename: Zi
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Ding
authors.affiliation: Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Yi
mesh_terms: D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000172:deficiency* / Q000235:genetics; D063988:3-Hydroxyacyl-CoA Dehydrogenase; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000235:genetics; D009202:Cardiomyopathies / Q000235:genetics*; D019175:DNA Methylation / Q000235:genetics*; D004195:Disease Models, Animal; D005227:Fatty Acids; D005260:Female; D006801:Humans; D050356:Lipid Metabolism; D008052:Lipid Metabolism, Inborn Errors / Q000235:genetics*; D063989:Long-Chain-3-Hydroxyacyl-CoA Dehydrogenase / Q000378:metabolism*; D051379:Mice; D017240:Mitochondrial Myopathies / Q000235:genetics*; D063991:Mitochondrial Trifunctional Protein / Q000172:deficiency; D009422:Nervous System Diseases / Q000235:genetics*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010920:Placenta; D011225:Pre-Eclampsia / Q000235:genetics / Q000378:metabolism*; D011247:Pregnancy; D012206:Rhabdomyolysis / Q000235:genetics*
chemical_list: D005227:Fatty Acids; C026512:arginine methyl ester; D001120:Arginine; D015094:3-Hydroxyacyl CoA Dehydrogenases; D063989:Long-Chain-3-Hydroxyacyl-CoA Dehydrogenase; D063988:3-Hydroxyacyl-CoA Dehydrogenase; D063991:Mitochondrial Trifunctional Protein