Reactive Oxygen Species Biology Research Articles

Genetics and the specificity of the aging process.

The identification and study of long-lived mutant animals has provided valuable insights into the mechanisms that limit the life-span of organisms. Findings with the gene SIR2 suggest that the rate of aging can be regulated under certain conditions. Indeed, increased expression of SIR2 lengthens life-span by acting on biological processes that promote survival under conditions of scarcity. In addition, studies of mutant strains of Caenorhabditis elegans, in particular daf-2, clk-1, and isp-1 mutants, suggest that the biology of reactive oxygen species in the mitochondria and elsewhere might be the main determinant of life-span in this organism. Thus, the aging process may be more specific than previously anticipated on evolutionary grounds.

Telomeres, sex, reactive oxygen species, and human cardiovascular aging.

By undergoing erosion with each replicative cycle, telomeres chronicle the replicative history of human somatic cells in vitro and in vivo. In human beings the telomere is relatively short, inversely correlated with age, highly heritable, and longer in women than men. However, it is not established whether the dynamics of telomere attrition in vivo has a role in the biology of human aging. Telomere attrition may be modified by reactive oxygen species, the biology of which is governed by processes that are influenced by sex. Indices of cardiovascular aging in humans are correlated with telomere length and this relationship is characterized by sexual dimorphism. In the final analysis, the biology of reactive oxygen species may offer a common explanation for some interindividual variation in cardiovascular aging and age-dependent telomere attrition in humans.

What is the ultimate fate of superoxide anion in vivo?

For three decades, oxidative stress and the role of reactive oxygen species in biology have been extensively studied. Recently, a new interest in these areas has emerged with the discovery of superoxide reductases, a family of familiar bacterial metalloenzymes whose heretofore unknown function has now been apparently revealed. In a series of experiments utilizing genetic, molecular biological, and biochemical methods, these enzymes have been shown to be physiologically competent at removing superoxide. The role of these enzymes and their biological relationship to the well-known superoxide dismutases is discussed.