Grapentine Sophie, Agarwal Prasoon, Dolinsky Vernon W, Bakovic Marica
Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada.
Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Canada.
PLoS One. 2025 Mar 28;20(3):e0320510. doi: 10.1371/journal.pone.0320510. eCollection 2025.
Aberrant DNA methylation can lead to the onset of pathological phenotypes and is increasingly being implicated in age-related metabolic diseases. In our preceding study we show that the heterozygous ablation of Pcyt2, the rate limiting enzyme in phosphatidylethanolamine (PE) synthesis, causes an age-dependent development of non-alcoholic steatohepatitis (NASH), and that treatment with the Pcyt2 substrate phosphonoethylamine (PEA) can attenuate phenotypic NASH pathologies. Here, we hypothesize that abnormal DNA methylation patterns underly the development of Pcyt2 + /- NASH. In this study, we conduct an epigenome-wide methylation analysis to characterize the differential methylation of Pcyt2 + /- livers and investigate whether the attenuation of NASH with PEA treatment is associated with changes in DNA methylation.
Pcyt2 + /- NASH liver experiences significant alterations in DNA methylation pattens relative to Pcyt2 + / + . Differentially methylated genes belong to pathways including PI3K-Akt signalling pathway, Foxo signalling pathway, oxidative phosphorylation and insulin signalling/secretion, indicating that epigenetic regulation underlies many of our previously established functional pathological mechanisms of Pcyt2 + /- NASH. Previously unidentified pathways during Pcyt2 deficiency are highlighted, such as cell cycle regulation and cellular senescence that may contribute to NASH development. Treatment with PEA dramatically attenuates aberrant total and protein-coding DNA methylation patterns by 96%. PEA treatment restored the methylation status of key genes involved in epigenetic modifications and induced differential methylation of genes associated with obesity and T2DM such as Adyc3, Celsr2, Fam63b.
The Pcyt2 + /- liver methylome and transcriptome is altered and likely underlies much of the pathology in Pcyt2 + /- NASH phenotype. The treatment with PEA significantly attenuates aberrant DNA methylation in Pcyt2 + /- liver and corrects the DNA methylation of genes involved in the pathogenesis of NASH, indicating its therapeutic potential. This analysis provides critical insight into the epigenetic basis of NASH pathophysiology and suggests diagnostic markers and therapeutic targets.
异常的DNA甲基化可导致病理表型的出现，并且越来越多地与年龄相关的代谢性疾病有关。在我们之前的研究中，我们表明磷脂酰乙醇胺（PE）合成中的限速酶Pcyt2杂合缺失会导致非酒精性脂肪性肝炎（NASH）的年龄依赖性发展，并且用Pcyt2底物膦酰乙胺（PEA）治疗可以减轻NASH的表型病理。在此，我们假设异常的DNA甲基化模式是Pcyt2 +/- NASH发展的基础。在本研究中，我们进行了全基因组甲基化分析，以表征Pcyt2 +/- 肝脏的差异甲基化，并研究PEA治疗对NASH的减轻是否与DNA甲基化的变化有关。
与Pcyt2 +/+ 相比，Pcyt2 +/- NASH肝脏的DNA甲基化模式发生了显著改变。差异甲基化基因属于包括PI3K-Akt信号通路、Foxo信号通路、氧化磷酸化和胰岛素信号/分泌等途径，表明表观遗传调控是我们之前建立的许多Pcyt2 +/- NASH功能病理机制基础。Pcyt2缺乏期间以前未被识别的途径被突出显示，例如可能导致NASH发展的细胞周期调控和细胞衰老。PEA治疗可使异常的总DNA甲基化和蛋白质编码DNA甲基化模式显著减轻96%。PEA治疗恢复了参与表观遗传修饰的关键基因的甲基化状态，并诱导了与肥胖和2型糖尿病相关基因的差异甲基化，如Adyc3、Celsr2、Fam63b。
Pcyt2 +/- 肝脏的甲基组和转录组发生了改变，可能是Pcyt2 +/- NASH表型中许多病理的基础。PEA治疗显著减轻了Pcyt2 +/- 肝脏中的异常DNA甲基化，并纠正了参与NASH发病机制的基因的DNA甲基化，表明其治疗潜力。该分析为NASH病理生理学的表观遗传基础提供了关键见解，并提出了诊断标志物和治疗靶点。
