Alcohol exposure in early pregnancy may change the gene function of tightly regulated embryonic development, thus inducing the developmental disorders, especially neurodevelopmental disorders; Through the study of alcohol-exposed human placenta and cultured human embryonic stem cells, new information on the effects of early alcohol exposure can be obtained.recently, A study published in the journal "Chromatin modifier developmental pluripotency associated factor 4 (DPPA 4) is a candidate gene for alcohol-induced developmental disorders" in the international journal BMC Medicine, Scientists from the University of Helsinki and other institutions analyzed for the first time the genome-wide effects of prenatal alcohol exposure on placental gene function and the epigenome, Epigenome is a molecular layer on the DNA chain that regulates gene expression, Methylation of DNA was the focus of this study, It is also a well-known epigenetic regulator.
In this study, the researchers jointly recruited 80 alcohol-exposed newborns and 100 control newborns, and when the researchers compared the placental epigenome of prenatal alcohol-exposed newborns with controls, they observed significantly lower levels of DNA methylation in alcohol-exposed newborns. In order to study the early effects of alcohol exposure, the researchers chose the most in the seventh week of pregnancy drinking mother pregnant newborn placental tissue separate analysis, hedgehog, in order to clarify the effects of alcohol exposure for the first human cells, the researchers also in the process of cultivating human embryonic stem cells exposed to alcohol.
Dr. Pauliina Auvinen said that we observed similar alcohol-related changes in DNA methylation levels in placenta and cultured human embryonic stem cells; this may suggest that the observed changes are directly related to alcohol exposure rather than luck to maternal smoking or other environmental factors, which may be difficult to exclude in any human study. Although in the early neonatal exposure to alcohol in birth weight or height and controls and no difference, but its head size is significantly reduced, according to the researchers, this may indicate that early prenatal alcohol exposure may have negative effects on brain development, but also accompany the observed epigenetic changes, which emphasizes the importance of early intrauterine environment for fetal development.
According to the current study, the researchers found that alcohol-related DNA methylation changes in placenta and embryonic stem cells were especially related to the development of the nervous system; researchers Nina Kaminen-Ahola pointed out that alcohol induces similar changes in DPPA 4 gene in the placenta and embryonic stem cells of neural cell lineage. This gene is only expressed in the initial stages of embryonic development and the protein produced promotes the differentiation of cells, so this gene may be a very essential gene for embryonic development. Moreover, alcohol exposure is also associated with altered DNA methylation of the FOXP 2 gene, which is important for the development of language regions in the brain during embryonic development.
The researchers said, these genes will affect large-scale gene regulation network and development, its function change may interfere with the strict regulation of embryo development, and causing a variety of developmental defects, because these changes will occur in the early development stage, so it may be retained as cell epigenetic memory, and along the cell division potential to different cell and tissue types. These widespread alterations (i. e., the epigenetic imprint of prenatal alcohol exposure) may serve as future biomarkers to promote early diagnosis and support for individualized treatment in affected children. Prenatal alcohol exposure induces various types of birth defects, known as fetal alcohol spectrum disorder (FASD, Fetal Alcohol Spectrum Disorders); alcohol is the major cause of neurodevelopmental disorders, and the diagnosis of body defects caused by prenatal alcohol exposure is difficult, and the true number of affected children is often unknown.
In conclusion, the results reveal the effects of early alcohol exposure on human embryonic and extraembryonic cells, but also identify candidate genes for developmental disorders induced by alcohol, and reveal potential biomarkers of prenatal alcohol exposure.
