DNA methylation status of imprinted H19 and KvDMR1 genes in human placentas after conception using assisted reproductive technology

Abstract

Background: Assisted reproductive technologies (ARTs), such as in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), are thought to destabilize genomic imprints. Previous studies examining the association between ART and aberrant DNA methylation have been inconclusive. Method:The DNA methylation status of H19 and KvDMR1was compared between newborns conceived through ART and those conceived naturally to evaluate the safety of ART. Placental tissues from 6 fullterm, naturally conceived pregnancies (no gestational comorbidities) and six full-term ART pregnancies (no gestational complication) were collected. Genomic DNA (gDNA) and RNA were extracted from both groups. Real-time PCR was used to analyze the mRNA expression levels of H19 and KvDMR1 in the placenta for both groups. A whole-genome DNA methylation microarray was used to examine three placentas from full-term, naturally conceived pregnancies and three placentas from full-term IVF pregnancies.Result: The expression level of H19 in the IVF group was significantly higher than that in the natural pregnancy group, whereas the expression level of KvDMR1 was significantly lower in the ART group than in the natural pregnancy group. Also, human ART manipulation resulted in placental gDNA methylation modifications. Conclusion: Abnormal methylation patterns were detected in phenotypically normal phenotype conceived by ART, which may occur due to imprinting errors in sperm/oocyte cells or side effects of in vitro embryo culture procedures. Further investigation is necessary to determine whether imprinted gene expression and DNA methylation can be regulated through other mechanisms.

The Consequences of Assisted Reproduction Technologies on the Offspring Health Throughout Life: A Placental Contribution

“…Specifically, H19/IGF2, LINE-1Hs , ERVFRD-1, and KCNQ1OT1 are affected in ART through changes in placental DNA methylation ( Turan et al, 2010 ; Nelissen et al, 2013 ; Choux et al, 2018 ; Dong et al, 2019 ). Expression of H19 is linked with fetal and placental growth suppression ( Gao et al, 2012 ) and was significantly higher ( Turan et al, 2010 ; Nelissen et al, 2013 , 2014 ; Sakian et al, 2015 ; Chi et al, 2020 ), while IGF2 expression , which increases fetal and placental growth ( Sakian et al, 2015 ; Chi et al, 2020 ) was significantly lower in ART compared with SC placentas ( Nelissen et al, 2014 ; Sakian et al, 2015 ; Chi et al, 2020 ). However, changes in DNA methylation do not always correlate with alterations in transcriptional levels ( Rancourt et al, 2012 ).…”

Molecular Markers: A New Paradigm in the Prediction of Sperm Freezability

“…Correct CpG methylation plays a major role in X-chromosome inactivation and the stability of chromatin and is directly associated with fertility potential and early embryo development. On the other hand, defective DNA methylation is characterized by unstable CpG methylation patterns, which correlate with sperm movement as well as DNA and chromatin integrity and lead to infertility or poor semen quality [ 74 , 75 , 76 , 77 , 78 ].…”

Epigenetics in the Uterine Environment: How Maternal Diet and ART May Influence the Epigenome in the Offspring with Long-Term Health Consequences

“…DNA methylation, following ART, has been investigated at different stages of development. Genome-wide DNA methylation profiling in cord blood and placenta revealed differences in the methylation status between ART and spontaneous conceiving populations at certain CpG sites [ 153 , 154 , 155 , 156 ]. In ICSI-manipulated oocytes, this can include an abnormal methylation status at imprinted genes at differentially methylated region 1 (DMR1), H19 DMR, and PEG1 DMR [ 157 ].…”