Objectives To analyze the micro-RNA(miRNA) expression profile in pancreas of type 1 diabetes (T1DM) model of NOD mouse and elucidate the association between miRNA and type 1 diabetes.Methods Twenty NOD mice were raised,and 3 mice sacrificed on 18 weeks,remaining were killed on 25 weeks.Pancreas sample were collected for pathological analysis to classify the insulitis.MicroRNA array were used to analyze miRNA expression profile in 3 samples with different grade of insulitis (0 grade,2nd grade,and 3rd grade insulitis),results were validated by quantitative reverse transcription-PCR in pancreas sample.Results 13/20 NOD mice developed diabetes by 25 weeks,there were 0-3 grades of insulitis.By microarray analysis,clustering analysis can distinguish insulitis with no insulitis; indicate a different miRNA profile in insulitis.Compared with no insulitis,2nd grade insulitis had 2 upregulated miRNA and 19 downregulated miRNA,while 3rd grade insulitis had 31 downregulated miRNA.For the 7 immune associated miRNA,miR-125b had significant downregulation,miR-125b-5p downregulated for 0.42 and 0.60 folds,miR-125b * and miR-125b-3p downregulated for 0.05 and 0.36 folds,which was validated by qRT-PCR.Conclusion Distinct miRNA expression profile is found during insulitis progression,indicating a potential role of miRNA in T1DM development.miR-125b has significant down-regulation effect in T1DM,which indicates its role for islet cell apoptosis.%目的 分析1型糖尿病(T1DM)小鼠胰腺中微小RNA表达谱,筛查T1DM相关微小RNA.方法 20只雌性6～8周龄T1 DM小鼠,体重(21 ±3)g,15周始测定血糖.于18、25周分期处死,18周处死的3只小鼠采用芯片方法分析T1DM小鼠胰腺中微小RNA表达谱；所有小鼠胰腺病苏木精-伊红染色和胰岛炎分级标准分级(胰岛炎0级；胰岛炎2级；胰岛炎3级+胰岛萎缩+显性糖尿病).胰腺提取RNA,经定量逆转录PCR(qRT-PCR)验证.结果 微小RNA芯片结果在聚类分析中,无胰岛炎归为一类,中度和重度胰岛炎归为一类.20只小鼠中有13只小鼠发生显性糖尿病,并存在0～3级的胰岛炎,2级、3级胰岛炎分别有21、31个微小RNA显著变化.对已报道的7个免疫相关微小RNA单独分析,6种无明显变化,但凋亡相关微小RNAmiR-125b存在下调趋势,miR-125b-5p下降倍数在NOD007、NOD006中分别为0.42和0.60倍,miR-125b*和miR-125b-3p均在2级胰岛炎变化最大,分别为0.05和0.36倍.定量PCR发现miR-125b表达在无胰岛炎组和胰岛炎组存在差异.结论 微小RNA表达随胰岛炎进展而变化,提示微小RNA在T1DM的发病中起重要作用.miR-125b参与了调节T1DM胰岛炎中胰岛细胞凋亡.
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