p21功能缺失在衰老背景下对小鼠MEF及胃部组织影响的研究

发布时间：2018-04-03 14:08

  本文选题：沃纳综合症(WS)　切入点：小鼠胚胎成纤维细胞　出处：《昆明理工大学》2016年硕士论文

【摘要】：胃癌在世界范围内是最常见的恶性肿瘤之一,其发病死亡率高,早期诊断率低。根据世界卫生组织(WHO)公布的全球统计报告,世界胃癌年发病率为13.86%/10万人,仅次于肺癌发病率而位居第二。我国是胃癌的高发区,每年新发现40万胃癌患者,占世界胃癌发病人数的42%。恶性肿瘤是严重威胁人类生命与健康的一大类疾病,据WHO报道,癌症将取代心血管疾病成为世界死亡人数最多的疾病。亚洲及南美洲国家的胃癌发病率远高于美国及其他西欧国家。引起胃癌发病的机理仍不是非常清楚,对于胃癌的基础研究目前越来越受到各国研究人员的重视。由于胃癌的高发年龄主要集中在中老年人群中,因此构建一个衰老动物模型来研究胃粘膜细胞的生理及病理变化将为基础研究提供一个独特的思路,对模拟衰老与胃部病变乃至胃癌的发生都将有所助益。早老综合症(Werner Syndrome,WS)是一种罕见的常染色体隐性遗传病,大约一百万人中会有一人罹患此病,该病也被视为是研究衰老的理想模型。为了在小鼠模型中模拟人类的早老综合症,我们通过双敲除Wm基因和端粒酶RNA组分来实现。在临床研究中发现,胃癌细胞中周期阻滞因子p21(Cdknla)表达异常。已有研究表明由端粒功能异常引起的DNA损伤信号中p21起到了很重要的作用。然而,p21与衰老相关的凋亡以及与胃部组织细胞的增殖活性之间的关系仍不明确。在本研究中,我们将较晚代端粒RNA组分敲除的小鼠(G2或G3mTerc-/-)和Wm基因敲除以及p2l基因敲除的小鼠进行杂交,得到G2或G3mTerc-/-Wrn-/-p21-/-小鼠。最终我们得到子代为G3mTerc-/-Wrn-/-和G3mTerc-/-wrn-/-p21-/-小鼠成纤维细胞(MEFs)以及G4mTerc-/-Wrn-/-和G4mTerc-/-Wrn-/-p21-/-小鼠并通过western blot技术分析检测MEFs凋亡相关蛋白的表达情况。G4 mTerc-/-Wrn-/-p21-/-小鼠出现明显的体格和活动力下降。运用流式细胞仪检测分析线粒体膜电位以及细胞凋亡情况,使用荧光免疫分析技术分析DNA损伤情况。结果显示,p21的功能缺失增强G3 mTerc-/-Wrn-/-MEFs凋亡增强以及DNA损伤增加。此外,通过SA-β-Gal染色法探究G4 mTerc-/-Wrn-/-p21-/-小鼠胃部组织的衰老情况。我们发现p21的功能缺失不仅没有缓解胃部组织细胞的衰老情况,而且能够加速小鼠胃部组织的衰老进程。另外,我们用BrdU掺入法评估G4mTerc-/-Wrn-/-p21-/-小鼠胃部组织细胞的增殖率。有意思的是,结果显示G4mTerc-/-Wrn-/-p21-/-小鼠胃部组织细胞的增殖效率显著提高。
[Abstract]:Gastric cancer is one of the most common malignant tumors in the world.According to the World Health Organization (WHO) global statistics report, the annual incidence of gastric cancer in the world is 138.6% of 100,000 people, second only to the incidence of lung cancer.China is a high incidence area of gastric cancer. 400000 new gastric cancer patients are found every year, accounting for 42 percent of the world gastric cancer.Malignant tumor is a serious threat to human life and health, according to WHO, cancer will replace cardiovascular disease to become the world's largest number of deaths.The incidence of gastric cancer in Asia and South America is much higher than in the United States and other Western European countries.The pathogenesis of gastric cancer is still unclear, and the basic research of gastric cancer has been paid more and more attention by researchers all over the world.Since the high incidence age of gastric cancer is mainly concentrated in the middle-aged and elderly population, the establishment of an aging animal model to study the physiological and pathological changes of gastric mucosal cells will provide a unique way of thinking for basic research.It will be helpful to simulate senescence, gastric lesion and even gastric cancer.Werner SyndromeWS), a rare autosomal recessive disease that affects about one in 1 million people, is also considered an ideal model for the study of aging.In order to mimic human premature syndrome in mouse models, we performed double knockout of the Wm gene and telomerase RNA components.In clinical studies, abnormal expression of cell cycle arrest factor p21 CDknlawas found in gastric cancer cells.It has been shown that p21 plays an important role in the signal of DNA damage caused by abnormal telomere function.However, the relationship between p21 and aging-related apoptosis and gastric tissue cell proliferation is still unclear.鏈，

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