英国《金融时报》7月29日报道称，《细胞》（Cell）杂志上周刊登的一项研究提出了减缓甚至扭转衰老过程的新可能性。
该研究显示，动物变老是由遗传学原因而非组织受损造成的。科学家们传统上认为，老化是细胞和组织长期磨损和破裂的必然结果，毒素、电离辐射、疾病和压力都会促使动物衰老和死亡。
现在，由斯坦福大学的斯图尔特·金带领的一个小组，正在对微小的线虫展开研究。他们发现，一种被称为ELT-3的生物学开关能够启动数百个涉及老化过程的基因，而当线虫变老时，ELT-3变得更加丰富。
科学家们尝试人为使这些线虫变老。他们让线虫受到热和辐射等压力，但是这些都不能对涉及老化过程的基因产生影响。金因此得出结论：越老的动物，其ELT-3的丰富度越高，而这是控制机制出错的结果。他称这种现象为“发育漂变”。
报道指出，如果老化不是化学过程造成的灾难结果，而是由于控制它的基因发生了改变，那么从理论上说，在任何水平上，老化速度都可以被减缓甚至停止。但是金还不能确定，发育漂变是否也出现在人类身上。（来源：中国新闻网）
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Copyright © 2008 Cell Press. All rights reserved.
Cell, Vol 134, 291-303, 25 July 2008
Cell, Vol 134, 291-303, 25 July 2008
Article
An elt-3/elt-5/elt-6 GATA Transcription Circuit Guides Aging in C. elegans
Yelena V. Budovskaya,1 Kendall Wu,1,3 Lucinda K. Southworth,2 Min Jiang,1 Patricia Tedesco,4 Thomas E. Johnson,4 and Stuart K. Kim1,2,
An elt-3/elt-5/elt-6 GATA Transcription Circuit Guides Aging in C. elegans
Yelena V. Budovskaya,1 Kendall Wu,1,3 Lucinda K. Southworth,2 Min Jiang,1 Patricia Tedesco,4 Thomas E. Johnson,4 and Stuart K. Kim1,2,
1 Department of Developmental Biology, Stanford University Medical Center, Stanford, CA 94305, USA
2 Stanford Medical Informatics, Stanford University Medical Center, Stanford, CA 94305, USA
3 Affymetrix, Inc., 3420 Central Expressway, Santa Clara, CA 95051, USA
4 Institute for Behavioral Genetics, Department of Integrative Physiology, University of Colorado, Boulder, Box 447, Boulder, CO 80309, USA
2 Stanford Medical Informatics, Stanford University Medical Center, Stanford, CA 94305, USA
3 Affymetrix, Inc., 3420 Central Expressway, Santa Clara, CA 95051, USA
4 Institute for Behavioral Genetics, Department of Integrative Physiology, University of Colorado, Boulder, Box 447, Boulder, CO 80309, USA
Summary
To define the C. elegans aging process at the molecular level, we used DNA microarray experiments to identify a set of 1294 age-regulated genes and found that the GATA transcription factors ELT-3, ELT-5, and ELT-6 are responsible for age regulation of a large fraction of these genes. Expression of elt-5 and elt-6 increases during normal aging, and both of these GATA factors repress expression of elt-3, which shows a corresponding decrease in expression in old worms. elt-3 regulates a large number of downstream genes that change expression in old age, including ugt-9, col-144, and sod-3. elt-5(RNAi) and elt-6(RNAi) worms have extended longevity, indicating that elt-3, elt-5, and elt-6 play an important functional role in the aging process. These results identify a transcriptional circuit that guides the rapid aging process in C. elegans and indicate that this circuit is driven by drift of developmental pathways rather than accumulation of damage.
