ABSTRACT
Objective By detecting the DNA methylation and gene expression of long-chain 3-hydroxyacyl CoA dehydrogenase (LCHAD) in trophoblast cells, analyze the correlation of DNA methylation and gene expression in early-onset preeclampsia (EPE), hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome and antiphospholipid syndrome (APS), to investigate the molecular basis of long-chain fatty acid oxidation changes in different preeclampsia and pathological pregnancy. Methods Primary human cytotrophoblast cells and HTR8/Svneo cells were treated with serum from patients with EPE (14 cases), HELLP (12 cases), APS (14 cases), and normal pregnant women (NP, 14 cases). The methylation level of LCHAD gene promoter region through the MassARRAY platform and mRNA expression level by real-time fluorescent quantitative PCR technique were conducted. Results (1) Cytosine-phosphate-guanine (CpG)sites in human LCHAD DNA promoter region:CpG sites were detected in the range of 558 bp before LCHAD gene transcription start site, the detected CpG sites were 11 sites including 8 single sites and 3 complex sites. The position of these sites were at-984,-960,-899,-853,-811,-796,-774,-727,-615,-595,-579 respectively. (2) The sites of-899,-853,-615 and-595 showed increased methylation level in EPE and HELLP groups. The methylation level at-899,-853 and-615 sites in EPE and HELLP groups were significantly higher than those in NP group(P<0.01). The methylation level at-853 site was higher in EPE group than that in HELLP group(P<0.05). The-595 site showed the unmethylated in EPE, HELLP and APS groups. There were significantly difference between the 3 groups and EPE group(P<0.01). (3) The gene expression of LCHAD mRNA in EPE(0.048±0.005), HELLP(0.045±0.006)and APS(0.044±0.004) groups were significantly lower than NP group(0.076 ± 0.009;P<0.01). (4) The correlation of methylation level and gene expression in all groups: the methylation level at-899,-853,-727,-615 and-579 sites were negatively correlated with gene mRNA expression in EPE group (P<0.05). The methylation level at-899,-853 and-615 sites were negatively correlated with gene mRNA expression in HELLP group(P<0.05). Conclusions The variation of LCHAD DNA methylation of trophoblast cells are found among EPE, HELLP syndrome and APS. The different correlation of LCHAD DNA methylation and gene expression are different in pathological groups. LCHAD DNA methylation of EPE and HELLP syndrome were significantly increased and negatively correlated with LCHAD gene mRNA expression. These results further revealed the molecular basis of long-chain fatty acid oxidation in different preeclampsia and pathological pregnancy.
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 ofβ-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 andβ-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).②The 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).③At 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).④At 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).⑥The 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 inβ-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 obviouscorrelation 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.
ABSTRACT
The pre-diagnostic test for preimplantation genetic diagnosis (PGD) of long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency was performed by polymerase chain reaction (PCR) and direct sequencing for hydroxyacyl-Coenzyme A dehydrogenase/3-ketoacyl-Coenzyme A thiolase/enoyl-Coenzyme A hydratase (HADHA) gene. We obtained unexpected genotyping results of HADHA gene by allele drop-out in the analysis of patients' genomic DNA samples with a referred PCR primer set. Upon further analysis with a re-designed primer set, we found a novel single nucleotide polymorphism (SNP) at the referred primer-binding site in the normal allele of HADHA gene (NT_022184, 5233296 a>t). We found that the frequency of this novel SNP was 0.064 in Korean population. Pre-diagnostic test using single lymphocytes and clinical PGD were successfully performed with the re-designed primer set. Nineteen embryos (95.0%) among 20 were successfully diagnosed to 5 homozygous mutated, 8 heterozygous carrier and 6 wild type. Among 6 normal embryos, well developed and selected 4 embryos were transferred into the mother's uterus, but a pregnancy was not achieved. We proposed that an unknown SNP at primer-binding sites would be a major cause of allele drop-out in the PGD for single gene dis-order.