新生期大鼠化学物暴露对睾丸DNA甲基化及精子生成的影响

目的 通过新生期大鼠暴露DNA甲基转移酶抑制剂(5-Aza-CdR)、镉(Cd)和多氯联苯153(PCB153),探讨化学物新生期暴露对SD大鼠睾丸DNA甲基化变化、细胞凋亡和精子生成的影响.方法 将出生3 d(postnatal day 3,PND3)SD大鼠随机分组,每组24只动物.经口给予溶剂对照5-Aza-CdR(0.025、0.250mg/kg)、PCB153(0.025、0.250、2.500mg/kg)和Cd(1、2、4mg/kg),连续暴露5 d.最后1次暴露24 h后,解剖每组的一半动物,剩余动物在无暴露条件下继续喂养至12周龄(成鼠)解剖.检测睾丸细胞凋亡和DNA甲基化水平.结果 与对照组比较,新生期大鼠5-Aza-CdR、PCB153和Cd暴露后,在12周龄时精子计数均呈下降趋势,差异有统计学意义(P<0.05).新生期化学物暴露后,与对照组相比,基因组整体DNA甲基化水平降低,新生期细胞凋亡上升,差异均有统计学意义(P<0.05). 5-Aza-CdR使p53启动子区BstUI位点甲基化水平下降,p53基因表达上调,提示p53通路可能是DNA甲基化诱导细胞凋亡的通路之一.新生期大鼠Cd暴露可诱导整体DNA甲基化变化,细胞凋亡增加,与对照组比较,差异有统计学意义(P<0.05),但p53 mRNA表达及p53启动子区BstUI位点甲基化水平和对照组相比,差异无统计学有意义(P>0.05),提示Cd暴露诱导的细胞凋亡可能是非p53通路依赖的.PCB153的体内暴露未发现基因组整体甲基化和细胞凋亡的明显变化.结论 新生期化学物体内暴露可诱导成年精子形成障碍.DNA甲基化异常和细胞凋亡可能是其中的机制之一.     

血清叶酸与RAR - β、MGMT甲基化在宫颈上皮内瘤变中的交互效应

目的 探讨血清叶酸与RAR - β、MGMT 启动子区CpG岛甲基化在宫颈上皮内瘤变（CIN）中的交互效应。方法 基于课题组建立于山西省（介休市和阳曲县）的已婚妇女人群队列,选取2014年6月 - 9月病理学确诊的CIN患者（CINⅠ147例、CINⅡ/Ⅲ 134例）及正常宫颈妇女（156例）为研究对象。收集全部对象人口学特征及相关因素,采集空腹静脉非抗凝血与宫颈脱落细胞。采用化学发光免疫法检测血清叶酸浓度,甲基化特异性PCR法检测基因CpG岛甲基化状态,导流杂交法判定HPV感染状况。采用Kruskal - Wallis H检验、χ2检验、趋势χ2检验进行资料分析,非条件logistic回归模型和交互作用指标评价交互效应。结果 血清叶酸在NC、CINⅠ和CINⅡ/Ⅲ组总体分布差异有统计学意义（P＜0.001）。低血清叶酸（≤23.13 nmol/L）可增加CINⅠ和CINⅡ/Ⅲ的发生风险（OR = 6.78,95%CI:3.75～12.26;OR = 64.13,95%CI:18.34～224.20）,且随病变进展,血清叶酸逐渐降低（χ2趋势 = 92.69,P＜0.001）。CIN组RAR - β、MGMT CpG岛甲基化率均高于NC组,且甲基化率随病变进展逐渐上升（χ2趋势 = 20.19,P＜0.001;χ2趋势 = 15.35,P＜0.001）。在各组中低血清叶酸与RAR - β、 MGMT CpG岛高甲基化均呈正相加交互作用（CINⅠ:S = 2.23,95%CI:1.63～8.08,S = 1.21,95%CI:1.01～10.01;CINⅡ/Ⅲ:S = 2.43,95%CI:1.72～6.80,S = 2.83,95%CI:1.55～8.10）,但未显示相乘交互作用（P＞0.05）。结论 低血清叶酸和RAR - β、 MGMT CpG岛高甲基化均可增加CIN的风险,且可能存在相加交互作用。     

Rotenone,an environmental toxin,causes abnormal methylation of the mouse brain organoid's genome and ferroptosis

More and more reports have pointed out that rotenone, as an insecticide, has high neurotoxicity and reproductive toxicity to livestock and mammals. As a highly physiological correlation system of internal organs, quasi-organs have great potential in the fields of drug toxicity and efficacy test, toxicology research, developmental biology and so on. In this study, brain organs (mBOs) derived from mouse neural stem cells were used to investigate the effects of rotenone on the physiological activity and epigenetic modification of mBOs. At the same time, Rotenone could significantly stimulate the increase of the concentration of LPO, lactic acid and hydroxyl radical in mBOs, and inhibit the expression of neuronal marker Tuj1, CHAT, PAX6 and so on. Further analysis showed that Rotenonem could induce mitochondrial damage in mBOs. The results of qPCR and Western blot showed that Rotenone could up-regulate the expressions of ferroptosis promoting protein p53, Cox2 and so on, while inhibit the expressions of negative regulatory protein of ferroptosis GPX4, FTH1, SLC7A11. In addition, the results of RRBS-Seq sequencing showed that the methylation modification at DMR level in Rotenone-treated mBOs group was significantly higher than that in Ctrl group. The results of KEGG analysis showed that compared with Ctrl, the genes with hypermethylation of promoter and Genebody in Rotenone-treated mBOs were mainly located in the Neuro active ligand-receptor interaction signal transduction pathway. In summary, rotenone can significantly lead to abnormal methylation of mouse brain organs, and lead to the loss of normal physiological function of neurons by inducing ferroptosis.     

Genome-wide DNA methylation analysis of human brain tissue from schizophrenia patients

Recent studies suggest that genetic and environmental factors do not account for all the schizophrenia risk, and epigenetics also has a role in disease susceptibility. DNA methylation is a heritable epigenetic modification that can regulate gene expression. Genome-wide DNA methylation analysis was performed on post-mortem human brain tissue from 24 patients with schizophrenia and 24 unaffected controls. DNA methylation was assessed at over 485 000 CpG sites using the Illumina Infinium HumanMethylation450 Bead Chip. After adjusting for age and post-mortem interval, 4641 probes corresponding to 2929 unique genes were found to be differentially methylated. Of those genes, 1291 were located in a CpG island and 817 were in a promoter region. These include NOS1, AKT1, DTNBP1, DNMT1, PPP3CC and SOX10, which have previously been associated with schizophrenia. More than 100 of these genes overlap with a previous DNA methylation study of peripheral blood from schizophrenia patients in which 27 000 CpG sites were analysed. Unsupervised clustering analysis of the top 3000 most variable probes revealed two distinct groups with significantly more people with schizophrenia in cluster one compared with controls (P=1.74 × 10⁻⁴). The first cluster composed of 88% of patients with schizophrenia and only 12% controls, whereas the second cluster composed of 27% of patients with schizophrenia and 73% controls. These results strongly suggest that differential DNA methylation is important in schizophrenia etiology and add support for the use of DNA methylation profiles as a future prognostic indicator of schizophrenia.     

外周血全基因组DNA甲基化水平与高脂血症发病风险的相关性分析

目的 探讨外周血全基因组DNA甲基化水平与高脂血症发病风险的相关性。方法 选取2019年1月-2021年1月医院门诊患者282例为研究对象,其中高脂血症患者162例(研究组),非高脂血症患者120例(对照组); 采集所有患者晨起空腹外周静脉血,采用高效液相色谱-串联质谱(Liquid chromatography-tandem mass spectrometry,LC-MS/MS)测定2组外周血全基因组DNA甲基化水平; 收集所有患者的相关资料,采用单因素分析影响高脂血症发病的可能相关因素; 采用Logistic多元回归分析影响高脂血症发病的相关因素; 采用Spearman相关性方法分析高脂血症患者外周血全基因组DNA甲基化水平与影响高脂血症发病因素之间的关系,并绘制受试者工作特征曲线(Receiver operating characteristic curve,ROC)分析外周血全基因组DNA甲基化水平对高脂血症的诊断价值。结果 研究组外周血全基因组DNA甲基化水平高于对照组(P<0.05)。研究组BMI≥23 kg/m²、高热量饮食占比高于对照组; 血清总胆固醇(Total cholesterol,TC)、甘油三酯(Triglyceride,TG)、低密度脂蛋白(Low density lipoprotein,LDL)水平均高于对照组; 高密度脂蛋白(High density lipoprotein,HDL)、总胆红素(Total bilirubin,TBIL)水平均低于对照组(P<0.05)。外周血全基因组DNA甲基化水平、TC,TG,HDL,TBIL均是影响高脂血症发病的相关因素(P<0.05)。Spearman相关性分析显示,外周血全基因组DNA甲基化水平与TC,TG水平呈正相关(r=0.321,0.334,P<0.05); 外周血全基因组DNA甲基化水平与HDL,TBIL水平呈负相关(r=-0.352,-0.341,P<0.05)。外周血全基因组DNA甲基化水平诊断高脂血症的最佳截断点为9.51%,ROC曲线下面积(AUC)为0.695,灵敏度为87.04%,特异度为81.67%。结论 高脂血症患者外周血全基因组DNA甲基化水平较高,是影响高脂血症发病的相关因素,与高脂血症发病风险有关,对于高脂血症具有良好诊断价值。     

人源肝癌细胞系中甲胎蛋白基因表达及甲基化的研究

目的:了解不同人源肝癌细胞系甲胎蛋白(AFP)基因表达及不同区域甲基化状态,探讨肝癌发生的表达遗传学调控机制。方法:采用亚硫酸氢盐-基因组测序(bisulfite-assisted genomic sequencing,BAGS)技术,检测人源HepG2、SMMC-7721肝癌细胞系和人成纤维细胞中AFP基因启动子区及CpG岛区的甲基化水平,RT-PCR检测基因的表达,并分析相关性。结果:HepG2细胞高表达AFP,SMMC-7721细胞低表达AFP,成纤维细胞不表达AFP;在启动子区,HepG2细胞的非甲基化修饰位点发生率较高,尤其是第一个和第二个CG位点,SMMC-7721细胞的甲基化程度较之高,而成纤维细胞甲基化程度整体很高;在CpG岛区,成纤维细胞的非甲基化修饰位点发生率较高,主要是第6个和第7个CG位点,SMMC-7721、HepG2细胞的甲基化程度较之高。结论:AFP基因启动子甲基化程度与基因表达水平存在负相关,AFP基因CpG岛甲基化程度与基因是否表达有关,AFP基因启动子低甲基化可能是AFP高表达的分子机制。     

贲门癌组织RASSF1A基因启动子甲基化测定

目的:检测贲门腺癌组织中RASSF1A基因启动子的甲基化.方法:取42例贲门腺癌患者癌及癌旁正常组织,用甲基化特异性聚合酶链反应(MSP)检测RASSF1A甲基化.结果:癌旁组织RASSF1A甲基化表达率为2%(1/42),而癌组织中达64%(27/42),2者比较,差异有统计学意义(x2=36.214,P＜0.05).结论:RASSF1A基因启动子区甲基化是贲门癌经常发生的分子事件,可成为对贲门腺癌高危人群进行筛选的一项重要候选指标.     

RUNX3基因启动子甲基化与乳腺癌临床病理特征及预后因素的关系

目的 探讨乳腺癌中抑癌基因RUNX3启动子甲基化状态与散发性乳腺浸润性导管癌临床病理特征及预后因素的关系.方法 运用甲基化特异性PCR(MSP)检测40例乳腺浸润性导管癌和15例乳腺增生病标本中RUNX3基因启动子甲基化状态,同时采用免疫组化SP法检测40例乳腺浸润性导管癌标本中ER、PR、C-erbB-2的表达水平.结果 乳腺浸润性导管癌组织中RUNX3基因启动子甲基化频率为47.5%,乳腺增生病组织中均未发生甲基化;RUNX3基因启动子甲基化与患者的年龄、淋巴结转移、PR、C-erbB-2阳性表达无相关性,与患者的病理组织学分级、临床分期、ER的阳性表达有相关性,差异有统计学意义.结论 RUNX3基因甲基化在散发性乳腺浸润性导管癌恶性进展中有一定作用,有可能成为乳腺癌预后不良的分子检测指标.