中国男性外周血淋巴细胞年龄效应的研究

发布时间：2018-06-13 03:05

本文选题：年龄效应 + 淋巴细胞　；参考：《中国科学技术大学》2009年硕士论文

【摘要】： 衰老是一种遗传因素和外界环境共同影响的,由在细胞水平上发生的变化逐步积累并最终表现在组织器官水平上的现象。在衰老的过程中,有许多因素会诱发细胞内遗传物质的损伤(基因突变、端粒缩短、细胞内调控机制失调等)。在这些与衰老有关的遗传物质的损伤中,最为明显的表现就是在细胞分裂过程中染色体分离异常的年龄效应以及非整倍体细胞的年龄效应。在本次研究中,我们采用cytokinesis-block method分别从染色体分离异常的角度以及非整倍体细胞命运的角度探讨在中国男性外周血淋巴细胞中的年龄效应: 1.运用cytokinesis-block method,我们首次研究并报道了在中国男性的外周血淋巴细胞中染色体分离异常的年龄效应。本文收集了14名老年(60-70岁之间)和10名青年(22-26岁之间)中国男性的外周血,从中分离得到淋巴细胞并进行培养,以松胞素B阻滞细胞质分裂而获得双核细胞,用人X、Y和2号染色体特异的着丝粒探针进行荧光原位杂交,以检测X和Y染色体的分离异常。发现:老年人淋巴细胞中,X染色体(老年组9.2±3.2‰,青年组1.1±0.9‰, P0.001)和Y染色体丢失的频率(老年组2.5±1.9%,年轻组0.2±0.3‰,P0.001)较青年人显著升高; X染色体(老年组16.5±3.4‰,年轻组3.5±1.1‰,P0.001)和Y染色体不分离的频率(老年组7.2±2.6‰,年轻组2.4±1.3‰,P0.001)也随着年龄增加而显著升高;在老年人和青年人的淋巴细胞中,无论X染色体还是Y染色体,其染色体不分离的频率均显著高于丢失的频率;观察到的多种染色体分离异常同时发生的频率也显著高于相应的预期频率。这些结果表明,年龄显著影响中国男性淋巴细胞中X和Y染色体的正常分离;与染色体丢失相比,染色体不分离是中国男性性染色体分离异常的是主要类型;细胞内负责染色体精确分离的机制出现异常可能会同时引起X和Y染色体的丢失及不分离。 2.我们分析发生了染色体分离异常的有丝分裂理论上应产生的子细胞,在理论上应产生的子细的群体中Chr X-细胞在淋巴细所占比例值为25.7‰,而我们在体内的外周血淋巴细胞群体中实际并未观察到Chr X-细胞,从这一结果中,我们发现X染色体的缺失对男性淋巴细胞的存活有极大的影响。此外,通过比较进入分裂形成双核的非整倍体淋巴细胞以及未进入分裂的单核非整倍体淋巴细胞,我们探讨了不同染色体的缺失或者获得对淋巴细胞分裂能力的影响。结果表明,在老年人的几种非整倍体外周血淋巴细胞中,Y染色体缺失的淋巴细胞(Chr Y-)的分裂能力最强(P0.001,χ2-test),与之不同的是,在年轻人的非整倍体外周血淋巴细胞中,Y染色体缺失的淋巴细胞(Chr Y-)的分裂能力与X染色体获得的淋巴细胞(Chr X+)相似(P=0.46,χ~2-test),而Y染色体获得的淋巴细胞(Chr Y+)的分裂能力最弱(P0.001,χ~2-test)。这一结果说明了在老年人和青年人中Y染色体对细胞分裂能力的不同影响,证实了Y染色体随年龄增长对细胞的功能和重要性的变化。综上所述,不同染色体的缺失或者获得对细胞命运的影响是不同的,并且这些染色体在年轻人和老年人细胞中的作用和影响也不同。
[Abstract]:Aging is a combination of genetic factors and external environment, which gradually accumulates at the level of cell and eventually appears at the level of tissue and organ. In the process of aging, there are many factors that induce the damage of genetic material in cells (gene mutation, telomere shortening, and dysregulation of intracellular regulation mechanism, etc.). The most obvious manifestation of the damage to genetic material related to aging is the age effect of abnormal chromosomal separation during cell division and the age effect of aneuploidy.
In this study, we used cytokinesis-block method to investigate the age effect in Chinese male peripheral blood lymphocytes from the angle of chromosomal segregation and the fate of aneuploidy, respectively.
1. using cytokinesis-block method, we first studied and reported the age effect of abnormal chromosomal segregation in the peripheral blood lymphocytes of Chinese men. This article collected the peripheral blood of 14 elderly (60-70 years old) and 10 young Chinese men (22-26 years old). X, Y, and chromosome 2 specific centromere probes were used for fluorescence in situ hybridization to detect the abnormal separation of X and Y chromosomes by blocking the cytoplasmic division. The frequencies of X chromosomes (aged 9.2 + 3.2%, 1.1 + 0.9 per thousand, P0.001) and Y loss were found in the lymphocytes of the elderly (2.5 + 1.9% in the elderly group). The young group was 0.2 + 0.3 per thousand, P0.001) was significantly higher than that of young people, and the frequency of X chromosome (aged 16.5 + 3.4%, 3.5 + 1.1 per 1000, P0.001) and Y chromosome non separation (aged 7.2 + 2.6 per 1000, young group 2.4 + 1.3 per thousand, P0.001) also increased with age; in the lymphocytes of the elderly and young people, no matter X chromosome or Y The frequencies of chromosomes were significantly higher than those of the lost frequency; the frequencies of abnormal chromosomal abnormalities observed at the same time were also significantly higher than the corresponding expected frequencies. These results suggest that age significantly affects the normal separation of X and Y chromosomes in Chinese male lymphocytes; chromosomes are not compared with chromosome loss. Separation is the main type of male sex chromosome segregation in China, and the abnormal mechanism of chromosomal separation in cells may cause the loss and separation of X and Y chromosomes at the same time.
2. we analyzed the subcells in the theory of mitosis that had occurred in chromosomal separation. In theory, the proportion of Chr X- cells in the subfine group was 25.7 per 1000, and we did not observe Chr X- cells in the peripheral blood lymphocyte population in the body. In this result, we found X The loss of chromosomes has a great effect on the survival of male lymphocytes. In addition, we have explored the loss of chromosomes or the effect on the mitosis of the cells by comparing into the division of the diploid aneuploidy lymphocytes and the mononuclear cells that have not entered the division. The Y chromosome missing lymphocyte (Chr Y-) has the strongest splitting capacity in several aneuploidy peripheral blood lymphocytes (P0.001, X 2-test) in several aneuploidy peripheral blood lymphocytes of the year, which is different from that of the Y chromosome missing lymphocyte (Chr Y-) and the X chromosome obtained lymphocyte (Chr X+) in the young's aneuploidy peripheral blood lymphocytes. Similar (P=0.46, X ~2-test), and the Y chromosome acquired lymphocyte (Chr Y+) is the weakest (P0.001, Chi ~2-test). This result illustrates the different effects of Y chromosome on cell division in the elderly and young people, and confirms the changes in the function and importance of the Y chromosome with age increasing. The effects of chromophore deletion or acquisition on cell fate are different, and these chromosomes play different roles in young and elderly cells.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2009
【分类号】：R392.12

【共引文献】