Genome

Biogerontology is the study of the aging of biological systems. This review addresses the relationship between chemistry and biology during aging, proposing that chemistry is responsible for the aging of biological systems. In the continuing struggle between chemistry and biology, chemistry is always the short-term, tactical winner--death of the individual is inevitable. However, barring the extinction of species, biology is the long-term, strategic victor--life survives, and the struggle continues.

Caloric restriction (CR) may retard aging processes and extend lifespan in organisms by altering energy-metabolic pathways. In CR rodents, glucose influx into tissues is not reduced, as compared with control animals fed ad libitum (AL), although plasma concentrations of glucose and insulin are lower. Gene expression profiles in rodents have suggested that CR promotes gluconeogenesis and fatty acid biosynthesis in skeletal muscle. In the liver, CR promotes gluconeogenesis but decreases fatty acid synthesis and glycolysis.

It is widely held that caloric restriction (CR) extends lifespan by preventing or reducing the age-related accumulation of irreversible molecular damage. In contrast, our results suggest that CR can act rapidly to begin life and health span extension, and that its rapid genomic effects are closely linked to its health effects. We found that CR begins to extend lifespan and reduce cancer as a cause of death within 8 weeks in older mice, apparently by reducing the rate of tumor growth.

Genetic studies in model organisms such as yeast, worms, flies, and mice leading to lifespan extension suggest that longevity is subject to regulation. In addition, various system-wide interventions in old animals can reverse features of aging. To better understand these processes, much effort has been put into the study of aging on a molecular level. In particular, genome-wide microarray analysis of differently aged individual organisms or tissues has been used to track the global expression changes that occur during normal aging.

OBJECTIVE: A systematic genome survey was initiated to identify loci that affect the likelihood of reaching age 90 with preserved cognition. This communication describes the clinical characterization and comparison of the experimental groups, validation of the experimental method, and results for the Y chromosome. METHODS: The genome survey was conducted at 10 cM resolution for simple sequence tandem repeat polymorphisms (SSTRPs) that identify genes for successful aging by virtue of linkage disequilibrium.

The naked mole rat (Heterocephalus glaber) is a strictly subterranean, extraordinarily long-lived eusocial mammal. Although it is the size of a mouse, its maximum lifespan exceeds 30 years, making this animal the longest-living rodent. Naked mole rats show negligible senescence, no age-related increase in mortality, and high fecundity until death. In addition to delayed ageing, they are resistant to both spontaneous cancer and experimentally induced tumorigenesis. Naked mole rats pose a challenge to the theories that link ageing, cancer and redox homeostasis.

Genome instability has long been implicated as the main causal factor in aging. Somatic cells are continuously exposed to various sources of DNA damage, from reactive oxygen species to UV radiation to environmental mutagens. To cope with the tens of thousands of chemical lesions introduced into the genome of a typical cell each day, a complex network of genome maintenance systems acts to remove damage and restore the correct base pair sequence.

Carbon nanotubes (CNTs) are one of widely used nanomaterials in industry and biomedicine. The potential impact of single-walled carbon nanotubes (SWCNTs) was evaluated using Caenorhabditis elegans (C. elegans) as a toxicological animal model. SWCNTs are extremely hydrophobic to form large agglomerates in aqueous solutions. Highly soluble amide-modified SWCNTs (a-SWCNTs) were therefore used in the present study so that the exact impact of SWCNTs could be studied. No significant toxicity was observed in C. elegans due to the amide modification.

Life prolongation with dietary restriction can be found in much of the animal kingdom and thus is a phenomenon that is evolutionarily conserved. We propose that one benefit of this is protection of the genome at lower dietary intake, perhaps by reduction of glycosylation related alterations and retardation of age related impairment of DNA repair.

Aging is an inevitable biological process that affects most living organisms. Despite the enormous consequences associated with the aging process, until recently, relatively little systematic effort has been expended on the scientific understanding of this important life process. Society, however, urged by an ever increasing older population, is challenging scientists from many disciplines to explore one of nature's most complex phenomena-biological aging.