随着年龄的增长，一种分子在人体中的浓度会自然减少，然而，科学家们发现，通过对这种分子实施管理，则可以显著提高细胞的寿命。新发现发表在《自然―细胞生物学》期刊上，清楚地显示出通过何种努力可以延长某种特定细胞的生命。
老化与哺乳类细胞的多种生物化学变化相关，比如一种名为亚精胺的分子在细胞中的减少。亚精胺是一种多胺化合物，存在于核糖体及活组织中，具有各种代谢功能，与细胞的生长和成长有关，然而，科学家们一直不清楚这种细胞的数量减少究竟是老化的原因呢，还是老化的结果。
Frank Madeo和同事发现，对果蝇、线虫和酵母体内的亚精胺实施管理，可提高这些生物的寿命。同样地，他们发现在培养液中加入额外的亚精胺可以延长人类细胞的寿命。这些发现显示，亚精胺能延长细胞的寿命，而且最终延长组织的寿命，因为它们提供了另一种清扫细胞的机制：不再是破坏细胞机制让细胞程序化死亡，亚精胺实际上是一种通道，让不必要且有潜在危险的细胞丧失功能。
生物谷推荐原始出处：
Nature Cell Biology 11, 1305 - 1314 (2009) 4 October 2009 | doi:10.1038/ncb1975
Induction of autophagy by spermidine promotes longevity
Tobias Eisenberg1, Heide Knauer1, Alexandra Schauer1, Sabrina Büttner1, Christoph Ruckenstuhl1, Didac Carmona-Gutierrez1, Julia Ring1, Sabrina Schroeder1, Christoph Magnes2, Lucia Antonacci1, Heike Fussi1, Luiza Deszcz3,4, Regina Hartl3,4, Elisabeth Schraml5, Alfredo Criollo6,7,8, Evgenia Megalou9, Daniela Weiskopf10, Peter Laun11, Gino Heeren11, Michael Breitenbach11, Beatrix Grubeck-Loebenstein10, Eva Herker12, Birthe Fahrenkrog13, Kai-Uwe Fr?hlich1, Frank Sinner2, Nektarios Tavernarakis9, Nadege Minois3,4,14, Guido Kroemer6,7,8 " Frank Madeo1
Ageing results from complex genetically and epigenetically programmed processes that are elicited in part by noxious or stressful events that cause programmed cell death. Here, we report that administration of spermidine, a natural polyamine whose intracellular concentration declines during human ageing, markedly extended the lifespan of yeast, flies and worms, and human immune cells. In addition, spermidine administration potently inhibited oxidative stress in ageing mice. In ageing yeast, spermidine treatment triggered epigenetic deacetylation of histone H3 through inhibition of histone acetyltransferases (HAT), suppressing oxidative stress and necrosis. Conversely, depletion of endogenous polyamines led to hyperacetylation, generation of reactive oxygen species, early necrotic death and decreased lifespan. The altered acetylation status of the chromatin led to significant upregulation of various autophagy-related transcripts, triggering autophagy in yeast, flies, worms and human cells. Finally, we found that enhanced autophagy is crucial for polyamine-induced suppression of necrosis and enhanced longevity.
1 Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria.
2 Institute of Medical Technologies and Health Management, Joanneum Research, Graz, Austria.
3 Research Institute of Molecular Pathology (IMP), Vienna, Austria.
4 Institute of Molecular Biotechnology (IMBA), Austrian Academy of Sciences, Vienna, Austria.
5 Institute of Applied Microbiology, University of Natural Resources and Applied Life Sciences, Vienna, Austria.
6 INSERM, U848; 94805 Villejuif, France.
7 Institut Gustave Roussy, 94805 Villejuif, France.
8 University Paris Sud, Paris-11, 94805 Villejuif, France.
9 Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, 70013, Heraklion, Crete, Greece.
10 Institute for Biomedical Ageing Research, Austrian Academy of Sciences, 6020 Innsbruck, Austria.
11 Department of Cell Biology, Division of Genetics, University of Salzburg, 5020 Salzburg, Austria.
12 Gladstone Institute of Virology and Immunology, San Francisco, CA 94158, USA.
13 M.E. Mueller Institute for Structural Biology, Biozentrum, University of Basel, 4056 Basel, Switzerland.
14 Current address: School of Biology, University of St Andrews, St Andrews, Scotland, Fife KY16 9AJ, UK.
