Mouse whole brain: Alteration of DNA methylation status caused by prenatal titanium dioxide nanoparticle exposure. Mouse whole brain: Alteration of DNA methylation status caused by prenatal titanium dioxide nanoparticle exposure

Reportedly, titanium dioxide nanoparticle exposure during pregnancy can affect the development of the central nervous system in mouse offspring; however, the underlying mechanism remains unknown. In the present study, we investigated the impact of prenatal dioxide nanoparticle exposure on global DNA methylation in the brains of neonatal mice. Pregnant C57BL/6J mice were intratracheally administered a dioxide nanoparticle suspension (100 ug/mouse) on gestational day 10.5, and brains were collected from male and female offspring at day 1 postpartum. After extraction of methylated DNA by immunoprecipitation, the DNA methylation profile was analyzed using a mouse CpG island microarray. Among genes in the CpG island microarray, DNA methylation was increased in 614 and 2924 genes and decreased in 6219 and 6463 genes in male and female offspring, respectively. Combined with mRNA microarray analysis, 88 and 89 genes were upregulated (≥ 1.5-fold) accompanied by demethylation of CpG islands, whereas 13 and 33 genes were downregulated (≤ 0.67-fold) accompanied by demethylation of CpG islands in male and female offspring mice, respectively. Gene Set Enrichment Analysis (GSEA) revealed that these genes were enriched in gene ontology terms related to the regulation of transcription factors, cell proliferation, and organism development. Additionally, MeSH terms related to stem cells and morphogenesis were enriched. Overall design: Alteration of DNA methylation status caused by prenatal titanium dioxie nanoparticle exposure (GD14: 100 ug/mouse) in mouse brain was analyzed. Brains were collected from male and female offspring at day 1 postpartum and DNA methylation profiles were analyzed (Vehicle vs. titanium nanoparticle; both male and female).

据报道，妊娠期间暴露于二氧化钛纳米粒子（titanium dioxide nanoparticle）可影响小鼠子代的中枢神经系统发育，但其潜在机制尚未明确。本研究探讨了产前暴露于二氧化钛纳米粒子对新生小鼠大脑全基因组DNA甲基化的影响。
妊娠C57BL/6J小鼠于妊娠第10.5天经气管内给予二氧化钛纳米粒子混悬液（100 μg/只），并于产后第1天采集雌雄子代的大脑组织。通过免疫沉淀法提取甲基化DNA后，利用小鼠CpG岛微阵列（mouse CpG island microarray）分析DNA甲基化谱。
在CpG岛微阵列覆盖的基因中，雄性和雌性子代小鼠分别有614个和2924个基因的DNA甲基化水平升高，另有6219个和6463个基因的DNA甲基化水平降低。结合mRNA微阵列分析结果，雄性子代小鼠中共有88个基因呈现上调（≥1.5倍）且伴随CpG岛去甲基化，另有13个基因呈现下调（≤0.67倍）且伴随CpG岛去甲基化；雌性子代小鼠中则分别有89个和33个符合上述变化特征的基因。
基因集富集分析（Gene Set Enrichment Analysis, GSEA）结果显示，这些差异甲基化基因富集于与转录因子调控、细胞增殖及机体发育相关的基因本体（Gene Ontology, GO）术语。此外，还富集到与干细胞及形态发生相关的医学主题词（Medical Subject Headings, MeSH）术语。
整体实验设计：分析产前二氧化钛纳米粒子暴露（妊娠第14天：100 μg/只）所致小鼠大脑DNA甲基化状态改变。于产后第1天采集雌雄子代的大脑组织，分析其DNA甲基化谱（溶剂对照组vs.二氧化钛纳米粒子暴露组，同时涵盖雌雄子代）。