DNA甲基化在胰岛组织特异性基因表达和分化中的作用研究

发布时间：2018-04-11 10:19

本文选题：DNA甲基化 + 基因表达　；参考：《暨南大学》2009年硕士论文

【摘要】： 目的:通过比较不同细胞类型胰岛组织特异性基因DNA甲基化程度差异及与基因表达的关系,探讨DNA甲基化在胰岛组织特异性基因表达和胰岛分化中的作用。方法:采用甲基化DNA免疫共沉淀—实时定量PCR法(MeDIP—qPCR)比较小鼠胰岛素瘤β细胞(NIT1)、NIH小鼠成纤维细胞(NIH3T3)及小鼠胚胎干细胞(mES)三者Pdx-1、Pax4、MafA、Nkx6.1和Insulin等基因转录起始区DNA甲基化程度差异。同时采用实时定量RT-PCR检测上述三种细胞各基因mRNA表达水平。比较这些基因DNA甲基化水平与基因表达之间的相互关系。结果:NIH3T3细胞Pdx-1、MafA和Nkx6.1基因转录起始区呈高甲基化,在NIT1细胞和mES细胞中这些基因则呈低甲基化,前者的甲基化程度明显高于后两者(P＜0.05)。另外两种基因Pax4和Insulin转录起始区在三种细胞中呈低甲基化,NIH3T3细胞Pax4基因的甲基化程度与NIT1细胞无统计学差异(P＞0.05);前者Insulin基因呈非甲基化,其甲基化程度低于后者(P＜0.05)。在基因表达方面,NIT1细胞高表达Pdx-1、Pax4、MafA、Nkx6.1和Insulin等基因,NIH3T3和mES细胞则未见这些基因表达。结果显示高甲基化状态的NIH3T3细胞无Pdx-1、MafA和Nkx6.1表达,而呈低甲基化状态的NIT1细胞则高表达Pdx-1、MafA和Nkx6.1。Pax4和Insulin基因甲基化状态与基因表达之间则无相关性。在胚胎干细胞中各基因呈低甲基化状态,也未见基因表达。结论:DNA甲基化参与了胰岛组织特异性基因的表达调控,且在胚胎干细胞向胰岛分化的过程中起重要调节作用。
[Abstract]:Aim: to investigate the role of DNA methylation in islet tissue specific gene expression and islet differentiation by comparing the degree of DNA methylation of islet specific genes in different cell types and the relationship between DNA methylation and gene expression.At the same time, real-time quantitative RT-PCR was used to detect the mRNA expression level of the three kinds of cells.To compare the correlation between DNA methylation level and gene expression of these genes.Results the transcription initiation region of Pdx-1mafA and Nkx6.1 gene was hypermethylated in the cell line of: NIH3T3, but it was hypomethylated in NIT1 cells and mES cells. The methylation degree of these genes in the former was significantly higher than that in the latter two cells (P < 0.05).There was no significant difference in the degree of methylation of the Pax4 gene between the two genes (Pax4 and Insulin) in the three cells (P > 0.05), but the former was demethylated and the degree of methylation was lower than that of the latter (P < 0.05).The expression of these genes in NIT1 cells was not found in NIH3T3 and mES cells.The results showed that there was no expression of Pdx-1mafA and Nkx6.1 in hypermethylated NIH3T3 cells, but there was no correlation between the methylation status of Pdx-1MafA and Nkx6.1.Pax4 and Insulin gene expression in NIT1 cells with low methylation state.The genes in embryonic stem cells were hypomethylated and no gene expression was found.Conclusion DNA methylation is involved in the regulation of islet tissue specific gene expression and plays an important role in the differentiation of embryonic stem cells into pancreatic islets.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2009
【分类号】：R657.5;R346

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