Department of Obstetrics and Gynecology and Reproductive Sciences, Center for Reproductive Sciences, University of California, San Francisco, CA94143, USA.
J Dev Orig Health Dis. 2022 Jun;13(3):358-366. doi: 10.1017/S2040174421000313. Epub 2021 Jun 14.
Offspring generated by in vitro fertilization (IVF) are believed to be healthy but display a possible predisposition to chronic diseases, like hypertension and glucose intolerance. Since epigenetic changes are believed to underlie such phenotype, this study aimed at describing global DNA methylation changes in the liver of adult mice generated by natural mating (FB group) or by IVF. Embryos were generated by IVF or natural mating. At 30 weeks of age, mice were sacrificed. The liver was removed, and global DNA methylation was assessed using whole-genome bisulfite sequencing (WGBS). Genomic Regions for Enrichment Analysis Tool (GREAT) and G:Profilerβ were used to identify differentially methylated regions (DMRs) and for functional enrichment analysis. Overrepresented gene ontology terms were summarized with REVIGO, while canonical pathways (CPs) were identified with Ingenuity® Pathway Analysis. Overall, 2692 DMRs (4.91%) were different between the groups. The majority of DMRs (84.92%) were hypomethylated in the IVF group. Surprisingly, only 0.16% of CpG islands were differentially methylated and only a few DMRs were located on known gene promoters (n = 283) or enhancers (n = 190). Notably, the long-interspersed element (LINE), short-interspersed element (SINE), and long terminal repeat (LTR1) transposable elements showed reduced methylation (P < 0.05) in IVF livers. Cellular metabolic process, hepatic fibrosis, and insulin receptor signaling were some of the principal biological processes and CPs modified by IVF. In summary, IVF modifies the DNA methylation signature in the adult liver, resulting in hypomethylation of genes involved in metabolism and gene transcription regulation. These findings may shed light on the mechanisms underlying the developmental origin of health and disease.
通过体外受精 (IVF) 产生的后代被认为是健康的,但却表现出可能易患高血压和葡萄糖不耐受等慢性疾病的倾向。由于表观遗传变化被认为是这种表型的基础,因此本研究旨在描述通过自然交配 (FB 组) 或 IVF 产生的成年小鼠肝脏中的全基因组 DNA 甲基化变化。通过 IVF 或自然交配产生胚胎。在 30 周龄时,处死小鼠。取出肝脏,使用全基因组亚硫酸氢盐测序 (WGBS) 评估全基因组 DNA 甲基化。使用基因组区域富集分析工具 (GREAT) 和 G:Profilerβ 识别差异甲基化区域 (DMR) 和功能富集分析。使用 REVIGO 总结过度表达的基因本体论术语,而使用 Ingenuity®Pathway Analysis 识别经典途径 (CP)。总体而言,两组之间有 2692 个 DMR(4.91%)不同。IVF 组中的大多数 DMR(84.92%)呈低甲基化。令人惊讶的是,只有 0.16%的 CpG 岛发生差异甲基化,只有少数 DMR 位于已知基因启动子(n=283)或增强子(n=190)上。值得注意的是,长散布元件 (LINE)、短散布元件 (SINE)和长末端重复 (LTR1)转座元件在 IVF 肝脏中的甲基化程度降低(P<0.05)。细胞代谢过程、肝纤维化和胰岛素受体信号转导是 IVF 修饰的一些主要生物学过程和 CP。总之,IVF 修饰了成年肝脏中的 DNA 甲基化特征,导致参与代谢和基因转录调控的基因低甲基化。这些发现可能为健康和疾病的发育起源的机制提供线索。