【摘要】：研究目的： 放射療法(Radiotherapy)是臨床上常用的癌癥治療手段。放療能夠有效抑制腫瘤組織增生，導(dǎo)致腫瘤細(xì)胞死亡；但同時(shí)對正常組織也具有一定的損傷作用。基于放療的抗癌療法會產(chǎn)生急性(acute)、亞慢性(subchronic)和晚期慢性(late chronic)副作用，這些副作用包括促炎、促纖維化、促細(xì)胞死亡等反應(yīng)，嚴(yán)重降低患者的生活質(zhì)量。因此，使用藥物手段干預(yù)輻射所致的應(yīng)激反應(yīng)，將是減輕放療副作用和提高患者生活質(zhì)量的有效治療策略。他汀類藥物（3-羥基-3-甲基戊二酸甲酰輔酶A還原酶抑制劑，3-hydroxy-3-methyl-glutaryl-CoA reductase inhibitors，statins），是一類廣泛使用的降脂藥。研究表明，他汀類藥物除了降脂作用之外，還對細(xì)胞應(yīng)激反應(yīng)、細(xì)胞增殖和凋亡等具有多重作用（pleiotropic effects）。值得注意的是，文獻(xiàn)報(bào)道他汀類藥物對輻射所致正常組織損傷還具有潛在的保護(hù)作用，其作用機(jī)制未有定論。因此，本課題在動(dòng)物、細(xì)胞水平探討了辛伐他汀(Simvastatin, SMV)是否能夠抑制輻射所致的小鼠胸腺細(xì)胞凋亡，并從Akt、Sirt-1、p53、bcl-2和DNA損傷修復(fù)酶PARP的表達(dá)方面進(jìn)行了機(jī)制探索。 研究內(nèi)容及結(jié)果： 1.辛伐他汀顯著減輕輻射所致的小腸和骨髓損傷 健康雄性C57/BL6小鼠隨機(jī)分為4組：對照組(Control)，辛伐他汀組(SMV)，輻射組(Radiation,4Gy)，輻射+SMV組(RS)。辛伐他汀組和輻射+SMV組輻射前給予20mg/kg/d的辛伐他汀，連續(xù)灌胃14天。輻射組和輻射+SMV組小鼠4Gy γ-60Co輻射后第7天斷頸處死，取各組小腸、骨髓組織進(jìn)行HE、TUNEL染色和Annexin V/PI凋亡檢測。發(fā)現(xiàn)：輻射會嚴(yán)重?fù)p害小腸、骨髓的形態(tài)，使小腸絨毛長度減短、骨髓出現(xiàn)空泡，使小腸和骨髓的凋亡細(xì)胞增多；辛伐他汀預(yù)處理能夠顯著減輕這些損傷。 2.辛伐他汀顯著抑制輻射所致小鼠胸腺的氧化應(yīng)激和細(xì)胞凋亡 取輻射后7天的胸腺組織，進(jìn)行超氧化物岐化酶(SOD)、丙二醛(MDA)水平檢測，并使用TUNEL染色與透射電鏡(TEM)觀察胸腺組織凋亡情況。發(fā)現(xiàn)：辛伐他汀預(yù)處理顯著抑制輻射所致小鼠胸腺的氧化應(yīng)激和細(xì)胞凋亡。 3.辛伐他汀抑制輻射所致小鼠胸腺細(xì)胞凋亡的機(jī)制 選取三個(gè)時(shí)間點(diǎn)，取輻射后1天、3天、7天的胸腺組織，提取胸腺組織蛋白，用Western blotting (WB)方法對小鼠胸腺組織內(nèi)Akt、Sirt-1、p53和bcl-2蛋白以及DNA修復(fù)相關(guān)酶PARP的表達(dá)進(jìn)行檢測。發(fā)現(xiàn)：辛伐他汀對輻射小鼠胸腺細(xì)胞凋亡的保護(hù)作用與Akt/bcl-2通路相關(guān)。 4.辛伐他汀顯著抑制體外培養(yǎng)胸腺細(xì)胞的凋亡 分離提取胸腺細(xì)胞并進(jìn)行體外培養(yǎng)，隨機(jī)分為4組：對照組(Control)，辛伐他汀組(SMV)，，輻射組(Radiation,8Gy)，輻射+SMV組(RS)。選擇辛伐他汀濃度為20μM，輻射劑量為8Gy γ-60Co輻射。選取1h、6h和24h三個(gè)時(shí)間點(diǎn)，使用Annexin V/PI凋亡分析法對胸腺細(xì)胞凋亡情況進(jìn)行檢測。發(fā)現(xiàn)：辛伐他汀可顯著抑制輻射所致體外培養(yǎng)胸腺細(xì)胞的凋亡。 5.辛伐他汀抑制輻射所致體外培養(yǎng)胸腺細(xì)胞凋亡的機(jī)制 胸腺細(xì)胞輻射后1h、6h和24h，提取胸腺細(xì)胞蛋白，用WB對胸腺細(xì)胞內(nèi)Akt、Sirt-1、p53、bcl-2和PARP的表達(dá)進(jìn)行檢測。發(fā)現(xiàn)：辛伐他汀對輻射所致體外培養(yǎng)胸腺細(xì)胞凋亡的保護(hù)作用與Akt/bcl-2通路相關(guān)。 結(jié)論：辛伐他汀能夠顯著減輕輻射所致小鼠的小腸、骨髓和胸腺損傷；辛伐他汀能夠顯著改善輻射所致胸腺細(xì)胞的凋亡，機(jī)制涉及Akt/bcl-2信號通路。
[Abstract]:Purpose of the study: Radiation therapy (Radioththerapy) is a clinically common treatment for cancer Radiotherapy can effectively inhibit the proliferation of tumor tissue and cause tumor cell death, but also has certain damage to normal tissues at the same time. Anti-cancer therapy based on radiotherapy can produce acute (acute), subchronic and late chronic side effects, including pro-inflammatory, pro-fibrosis, cell death, etc., severely reducing the patient's life Therefore, the use of drug means to interfere with the stress response caused by radiation will be an effective treatment to reduce the side effects of radiotherapy and improve the quality of life of the patient Strategy. Statins (3-hydroxy-3-methylpent-2 acid, coenzyme A reductase inhibitor, 3-hydroxy-3-methyl-glutayl-CoA reductase inhibitors, stats) are widely used. in addition to lipid-lowering effect, pastatin has multiple roles in cell stress response, cell proliferation and apoptosis, in addition to lipid-lowering effect. (s). It is worth noting that the literature reports that statin drugs have a potential protective effect on normal tissue damage caused by radiation, and the mechanism of action has not been Objective: To investigate whether Simvastatin (Simvastatin) could inhibit the apoptosis of thymocytes induced by radiation in animals and cells, and the mechanisms of the expression of Akt, Sirt-1, p53, bcl-2 and DNA damage repair enzyme PARP were discussed. Exploration and research Content and results: 1. Simvastatin significantly reduced radiation The small intestine and bone marrow damaged healthy male C57/ BL6 mice were randomly divided into four groups: control group (control group), simvastatin group (control group), radiation group (Radiation, 4Gy). Radiation + Alarm Group (RS). Simvastatin and Radiation + Treatment Group Radiation before radiation dose of 20mg/ kg/ day Cuvastatin was administered continuously for 14 days. The radiation group and the irradiation group were sacrificed at the 7th day after irradiation with 4Gy Et-60Co radiation in the radiation group and the irradiated group. The small intestine and bone marrow tissues of each group were used for HE staining and Anne staining. xin V/ PI apoptosis detection. It was found that radiation could seriously damage the morphology of small intestine and bone marrow, shorten the length of small intestinal villi, vacuoles in the bone marrow, increase the number of apoptotic cells in the small intestine and bone marrow, and pre-place simvastatin. that can significantly reduce these damage. Simvastatin significantly inhibits radiation. The oxidative stress and apoptosis of thymocytes in mice were detected by SOD and MDA in 7 days after irradiation. The apoptosis of thymocytes was observed by electron microscopy (TEM). Oxidative stress and apoptosis of thymocytes induced by injection. Simvastatin inhibited thymocyte apoptosis in mice induced by radiation, three time points were selected, the thymus tissue was extracted for 1 day, 3 days and 7 days after radiation, the thymocyte protein was extracted, and Western blotting was used. Effects of WB method on Akt, Sirt-1, p53 and bcl-2 in mouse thymocytes Detection of the expression of protein and DNA repair-related enzyme PARP. Protective effect of apoptosis and Akt/ bcl-2 pathway 4. Simvastatin significantly inhibited the apoptosis of thymocytes in vitro and extracted thymocytes and cultured in vitro, randomly divided into 4 groups: control group (control group), simvastatin group (control group), spokes. Radiography (8Gy), Radiation + Response Group (RS). Selected The concentration of simvastatin was 20. m u.M, and the radiation dose was 8Gy LW-60Co radiation. Apoptosis of thymocytes by Annexin V/ PI apoptosis analysis method It was found that simvastatin could significantly inhibit the proliferation of thymocytes in vitro induced by radiation. Apoptosis of thymocytes. 5. Simvastatin inhibits the proliferation of thymocytes induced by radiation, 1h, 6h, and 24h after radiation of thymocytes, extracts thymocyte proteins, and uses WB to treat thymocytes. The expression of Akt, Sirt-1, p53, bcl-2 and PARP in cells was detected. Conclusion: Simvastatin can significantly reduce the damage of small intestine, bone marrow and thymus of mice induced by radiation.
【學(xué)位授予單位】：第二軍醫(yī)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：R965

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 周平坤;霍艷英;吳德昌;;輻射致癌效應(yīng)與機(jī)制[J];輻射防護(hù)通訊;2007年01期

2 童新,孫志賢;輻射所致程序性細(xì)胞死亡的機(jī)制[J];國外醫(yī)學(xué)(分子生物學(xué)分冊);1995年03期

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