本文選題：亞砷酸鈉 + 大鼠胰島β細(xì)胞�。� 參考：《大連醫(yī)科大學(xué)》2013年碩士論文

【摘要】：目的:砷（As）是一種廣泛存在于地殼中的類金屬元素，主要以有機(jī)砷和無機(jī)砷兩種形式存在，其中無機(jī)砷的毒性更強(qiáng)。人類接觸砷最主要的途徑是環(huán)境暴露，如接觸被砷污染的水源。近年有研究顯示，長期居住在富砷地區(qū)的人群糖尿病高發(fā)，提示砷可能對胰島細(xì)胞具有毒性作用。有研究證實(shí)砷可引起胰島細(xì)胞凋亡和DNA損傷。但關(guān)于砷對胰島細(xì)胞癌基因和抑癌基因表達(dá)及其編碼的蛋白質(zhì)的影響尚不明確。本研究探討了砷對胰島細(xì)胞p53、mdm2和Kras等基因和蛋白表達(dá)的影響。 方法：選定大鼠胰島β細(xì)胞（INS-1）。用MTT法檢測亞砷酸鈉對INS-1的毒性作用。用熒光實(shí)時(shí)定量PCR法檢測亞砷酸鈉對大鼠胰島β細(xì)胞野生型p53（Tp53）、mdm2和Kras基因表達(dá)的影響。用Western blot免疫印跡檢測亞砷酸鈉對大鼠胰島β細(xì)胞內(nèi)突變型p53蛋白和mdm2蛋白表達(dá)的影響。 結(jié)果：（1）亞砷酸鈉對大鼠胰島細(xì)胞的毒性作用：亞砷酸鈉（0、2.5、5、10、20、40、80、160μM）在37℃條件下，分別作用于INS-1細(xì)胞48h和72h后， OD值隨濃度的遞增而降低，，細(xì)胞存活率隨著亞砷酸鈉劑量的增大而降低，計(jì)算IC50分別為5.66μM、2.78μM；（2）亞砷酸鈉對大鼠胰島細(xì)胞Tp53、mdm2和Kras基因表達(dá)的影響：48h染毒各組Tp53（野生型p53腫瘤抑制基因）表達(dá)呈下降趨勢， mdm2、Kras基因表達(dá)增高；72h染毒中、低劑量組Tp53腫瘤抑制基因表達(dá)下降更加明顯，中、高劑量組Kras基因表達(dá)率升高更加明顯；（3）亞砷酸鈉對大鼠胰島細(xì)胞突變型p53蛋白和mdm2蛋白質(zhì)表達(dá)的影響：48h染毒后中、高劑量組突變型p53蛋白表達(dá)明顯增加，低劑量組突變型p53蛋白表達(dá)無明顯變化；72h染毒各組突變型p53蛋白表達(dá)均增加；而48h染毒和72h染毒均為中、高劑量組mdm2蛋白表達(dá)增加；72h染毒組與48h染毒組相比，中、高劑量染毒的p53蛋白表達(dá)量增加的差別顯著。 結(jié)論：亞砷酸鈉作用于INS-1可造成細(xì)胞內(nèi)抑癌基因Tp53表達(dá)率降低，且致癌基因mdm2和Kras的表達(dá)率增加；砷可導(dǎo)致INS-1細(xì)胞Tp53向突變型p53的轉(zhuǎn)變。
[Abstract]:Objective: as is a kind of metalloid element in the crust, which mainly exists in organic arsenic and inorganic arsenic, among which inorganic arsenic is more toxic. The main route of human exposure to arsenic is environmental exposure, such as exposure to water contaminated by arsenic. Recent studies have shown that there is a high incidence of diabetes in people living in arsenic-rich areas for a long time, suggesting that arsenic may have toxic effects on islet cells. Studies have shown that arsenic can induce apoptosis and DNA damage in islet cells. However, the effects of arsenic on the expression of oncogenes and tumor suppressor genes in islet cells and the proteins encoded by them are unclear. In this study, we investigated the effects of arsenic on the expression of p53 mdm2 and Kras genes and proteins in islet cells. Methods: rat islet 尾 cells were selected. The toxicity of sodium arsenite to INS-1 was detected by MTT method. The effect of sodium arsenite on the expression of wild-type p53Tp53mdm2 and Kras in rat islet 尾 cells was detected by real-time fluorescence quantitative PCR. The effect of sodium arsenite on the expression of mutant p53 and mdm2 protein in rat islet 尾 cells was detected by Western blot Western blot. Results the toxic effect of sodium arsenite on islet cells of rats: sodium arsenite at 37 鈩

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