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遗传学家发现寿命延长到800岁的方法
现在发现了一种延长有机体寿命的新方法，预计这样一来人类可以活到800岁。通过这项了不起的发现，南加州大学的科学家们宣布他们已经延长了酵母菌十倍的寿命，并且他们使用的这种模式可以很容易转化到人类，通过修补两种基因并削减你的卡路里摄取量达到延长寿命的目的。测试已经开始对厄瓜多尔的人群中展开。
根据公共科学图书馆PLoS·遗传学如下的一篇声明：
研究人员已经使面包酵母(baker' s yeast)能够活到800岁且无明显副作用。通过结合膳食和遗传变化完成的这一基础而重要的发现使科学家向控制所有生命系统的单位--细胞的生存与健康又迈进了一步。南加州大学的研究带头人Valter Longo教授认为：\"我们正在建立重新编撰健康生活的基础\"。
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Longo教授的团队以卡路里限制面包酵母的饮食方式给予培养，并将两个会造成酵母菌老化以及人类致癌的基因-RAS2以及SCH9自细胞中移除。
Longo教授称，“我认为，我们可以延长十倍的寿命，这是目前所有成功研究中延长生命体寿命最长的一次”。
国家老化学院(NIA)遗传和细胞生物分部的部长、Longo教授项目的官员Anna McCormick补充道，我得说10倍是非常巨大的一个数字。国家老化学院正资助该项研究，希望通过开发出可以模拟Longo教授及其他人使用的延长寿命的技术的药物，延长人类的健康寿命。
面包酵母是在分子和基因水平上研究得最多和了解得最深的生命体。值得注意的是，鉴于其简明性，酵母已引发了一些极为重要的基因和调节小鼠及其他哺乳动物衰老和疾病的方法的发现。
Longo教授团队接下来计划进一步研究老鼠寿命的延长。该研究小组已经正在研究厄瓜多尔地区人民身上与酵母类似的突变。
Longo教授说，“有两个拷贝突变的人身材矮小，并有其他缺陷。我们目前正在确定他们只有一个拷贝突变、表面上却看来正常的亲人。我们希望他们发病率降低，寿命延长”。
Longo教授告戒说，如厄瓜多尔地区病历一样，长寿突变往往伴随严重的增长不足和其他健康问题。寻找延长人类寿命的无副作用药物并不容易。
此研究成果发表于1月25日的PLOS Genetics期刊上
http://www.worldhealth.net.cn
原文出处http://genetics.plosjournals.org ... 040013.eor&ct=1
摘要如下
Calorie restriction-induced life span extension depends on Rim15 and stress response transcription factors downstream of Ras/cAMP/PKA, Tor and Sch9
Min Wei1, Paola Fabrizio1, Hu Jia1, Huanying Ge1, Chao Cheng1, Lei Li1, Valter Longo1¤
1 University of Southern California, United States of America
Calorie restriction, the only non-genetic intervention known to slow aging and extend life span in organisms ranging from yeast to mice, has been linked to the down-regulation of Tor, Akt, and Ras signaling. In this study, we demonstrate that the serine/threonine kinase Rim15 is required for yeast chronological life span extension associated with the deficiencies in Tor and Ras signaling, and show that it is also required for the longevity promoting effect of both extreme (water) and standard (0.5% glucose) calorie restriction. Deletion of stress resistance transcription factors Gis1 and Msn2/4, which are positively regulated by Rim15, also caused a major although not complete reversion of the effect of calorie restriction on life span. Surprisingly, the lack of Rim15 only partially decreased the 10-fold life span extension caused by the combination of CR and the deletion of both RAS2 and SCH9/AKT. These results suggest that Rim15 functions as a central regulator of stress resistance and longevity downstream of the Ras/cAMP/PKA, Tor and Sch9 pathways during calorie restriction. Transcription factors Msn2, Msn4, and Gis1 are also important for Rim15-dependent life span extension but that additional mediators are involved.
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关于热量限制延长寿命的反对意见
Shanley DP, Kirkwood TB.2006. Caloric restriction does not enhance longevity. Biogerontology. 2006 Jun;7(3):165-8. Calorie restriction is known to increase lifespan in many but not all species and may perhaps not do so in humans. Exceptions to life extension have been identified in the laboratory and others are known in nature. Given the variety of physiological responses to variation in food supply that are possible, evolutionary life history theory indicates that an increased investment in maintenance in response to resource shortage will not always be the strategy that maximises Darwinian fitness. Additionally, for the well-studied species in which life extension is observed, there is considerable variation in the response. This suggests that it is not an ancient ancestral response, which has been conserved across the species range. Although calorie restriction does not increase lifespan in all species, it remains a fascinating and valuable tool to study ageing at the whole organism level.
Kirkwood TB. 2008. A systematic look at an old problem. Nature 451, 644-647 (7 February 2008). As life expectancy increases, a systems-biology approach is needed to ensure that we have a healthy old age.
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发表于 2008-2-27 11:08:37
