While medical science and a healthy lifestyle can help increase life expectancy, many aspects of aging and longevity are beyond our control. Published this week in the open-access journal PLoS Biology, Michael Eisen and colleagues shed light on these genetic factors by identifying sets of genes whose expression changes with age in human and chimp brains.

Using results from three microarray data studies performed in old and young humans and chimps in four different regions of the cortex (the brain region responsible for functions such as thinking), the authors found a pattern of age-related changes in the expression of hundreds of genes. Only one non-cortical region, the cerebellum (whose principal functions include movement), showed little change in age-related gene expression. Intriguingly, the set of affected cortical genes was different between humans and chimps. Since humans and chimps diverged about 5 million years ago - these changes have accumulated over a relatively short evolutionary time.

What might account for the difference? One common theory of aging holds that damage is done to DNA and proteins by "free-radicals" (highly reactive molecules produced by the metabolic activity of mitochondria). It predicts that more metabolically active tissues will show greater age-related differential gene expression. The results of this study support this theory since the more metabolically active cortex shows a greater reduction in gene activity.

These results raise questions about age-related gene expression changes, including whether metabolically active non-brain tissues display similar patterns, and whether the divergence between human and chimp patterns was the direct result of selection or an inevitable consequence of some other difference in brain evolution. The patterns seen here provide a starting point for understanding genetic changes in aging, and may reveal targets for treatment of neurodegenerative diseases.

'"/>

Contact: Paul Ocampo
press@plos.org
415-624-1224
Public Library of Science
1-Aug-2005

Page: 1
Related biology news :

1. A low expression of MX2 gene exists in the white blood cells of narcoleptics
2. Gene expression pattern could lead to improved treatment of pediatric septic shock
3. Boston Univeristy bioengineers devise dimmer swith to regulate gene expression in mammal cells
4. Clocking in and out of gene expression
5. High cholesterol diets modify gene expression in atherosclerosis
6. Gene expression patterns predict rapid decline in idiopathic pulmonary fibrosis patients
7. Decoding gene expression in cancer tumors using noninvasive imaging
8. Growing nerve cells in 3-D dramatically affects gene expression
9. XDx to present recent success with AlloMap molecular expression testing
10. Fat tissue-derived hormone leptin increases e-cadherin expression, obesity-breast cancer link noted
11. Clues to gene expression in cystic fibrosis will guide research