【摘要】： 胰腺是一個重要的內(nèi)外分泌混合腺,胰腺內(nèi)分泌部中的β細(xì)胞缺失或發(fā)生功能障礙就會導(dǎo)致糖尿病,而外分泌細(xì)胞異常增殖會導(dǎo)致胰腺癌癥的發(fā)生。因而研究胰腺器官發(fā)生發(fā)展的機(jī)制對于胰腺疾病的治療具有重要意義。Ptfla(bHLH轉(zhuǎn)錄因子)是胰腺特化與外分泌分化所必需的轉(zhuǎn)錄因子。最近研究發(fā)現(xiàn),Ptfla調(diào)控胰腺細(xì)胞的分化存在劑量依賴性:低水平的Ptfla促進(jìn)內(nèi)分泌分化,高水平Ptfla抑制內(nèi)分泌分化促進(jìn)外分泌分化。然而,胰腺不同發(fā)育命運(yùn)細(xì)胞中Ptfla的表達(dá)調(diào)節(jié)機(jī)制還不清楚。 MicroRNAs(miRNAs)是一類22nt左右的非編碼小RNA,它們在進(jìn)化過程中高度保守,通過切割靶mRNA或抑制靶mRNA的翻譯來調(diào)節(jié)基因的表達(dá)。一些研究已經(jīng)表明,miRNAs在胰腺發(fā)育及功能調(diào)節(jié)中起重要作用,但目前還不知道哪些miRNAs在發(fā)育的胰腺上皮中調(diào)控Ptfla的表達(dá)。 為了解決這一問題,我們首先結(jié)合兩個預(yù)測算法的結(jié)果,預(yù)測得到4個可能調(diào)控Ptfla表達(dá)的miRNAs。隨后,我們通過雙熒光素酶報(bào)告系統(tǒng)證明其中3個miRNAs(miR-18,miR-145和miR-495)確實(shí)對Ptfla的表達(dá)起到調(diào)控作用。通過qRT-PCR試驗(yàn)發(fā)現(xiàn),在小鼠胰腺發(fā)育過程中miR-18a和Ptfla mRNA的表達(dá)模式成負(fù)相關(guān);而免疫熒光染色試驗(yàn)顯示miR-145/miR495與Ptfla蛋白的表達(dá)模式成負(fù)相關(guān)。最后,為了進(jìn)一步了解小鼠胰腺發(fā)育過程中Ptfla相關(guān)的分子機(jī)制,我們結(jié)合以往文獻(xiàn)數(shù)據(jù)與本文研究結(jié)果,繪制了小鼠胰腺發(fā)育中Ptfla相關(guān)的調(diào)控通路。 綜上所述,本研究證明miR-18a,miR-145和miR-495可抑制Ptfla的表達(dá),并參與到小鼠胰腺發(fā)育中Ptfla相關(guān)的調(diào)控網(wǎng)絡(luò)中。
[Abstract]:The pancreas is an important mixture of internal and external secretory glands. The absence or dysfunction of 尾 cells in the endocrine region of the pancreas will lead to diabetes mellitus, while abnormal proliferation of exocrine cells will lead to the occurrence of pancreatic cancer. Therefore, it is important to study the mechanism of pancreatic organogenesis and development for the treatment of pancreatic diseases. Ptfla (bHLH transcription factors are essential transcription factors for pancreatic specialization and exocrine differentiation. Recently, it has been found that Ptfla regulates pancreatic cell differentiation in a dose-dependent manner: low level of Ptfla promotes endocrine differentiation, high level of Ptfla inhibits endocrine differentiation and promotes exocrine differentiation. However, the regulatory mechanism of Ptfla expression in cells with different developmental fate of pancreas is not clear that. MicroRNAs (miRNAs) is a kind of non-coding small RNA, around 22nt, which is highly conserved in evolution. Gene expression is regulated by cutting target mRNA or inhibiting target mRNA translation. Some studies have shown that miRNAs plays an important role in pancreatic development and function regulation, but it is not known which miRNAs regulates the expression of Ptfla in the developing pancreatic epithelium. In order to solve this problem, we first combine the results of two prediction algorithms to predict four miRNAs. that may regulate the expression of Ptfla. Subsequently, we demonstrated that three of the miRNAs (miR-18,miR-145 and miR-495) did regulate the expression of Ptfla by double luciferase reporting system. The expression pattern of miR-18a and Ptfla mRNA was negatively correlated with the expression pattern of miR-145/miR495 and Ptfla protein during the development of mouse pancreas by qRT-PCR assay, while the expression pattern of Ptfla protein was negatively correlated with the expression pattern of miR-145/miR495 by immunofluorescence staining. Finally, in order to further understand the molecular mechanism related to Ptfla during the development of mouse pancreas, we draw the regulatory pathway of Ptfla related to the development of mouse pancreas based on previous literature data and the results of this study. In conclusion, this study suggests that miR-18a,miR-145 and miR-495 can inhibit the expression of Ptfla and participate in the regulatory network related to Ptfla in the development of mouse pancreas.
【學(xué)位授予單位】：東北林業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2009
【分類號】：R346

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前2條

1 李丹;成體小鼠胰腺單細(xì)胞的離體分離、分析及培養(yǎng)[D];東北林業(yè)大學(xué);2011年

2 楊艷坤;MicroRNA-18a在胰腺祖細(xì)胞和腺泡細(xì)胞中對轉(zhuǎn)錄因子Ptf1a的調(diào)控研究[D];東北林業(yè)大學(xué);2012年

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本文編號：2271707