Catálogo de publicaciones - revistas

<jats:p>Mitochondria generate adenosine 5′-triphosphate (ATP) and are a source of potentially toxic reactive oxygen species (ROS). It has been suggested that the gradual mitochondrial dysfunction that is observed to accompany aging could in fact be causal to the aging process. Here we review findings that suggest that age-dependent mitochondrial dysfunction is not sufficient to limit life span. Furthermore, mitochondrial ROS are not always deleterious and can even stimulate pro-longevity pathways. Thus, mitochondrial dysfunction plays a complex role in regulating longevity.</jats:p>

<jats:p> Nicotinamide adenine dinucleotide (NAD <jats:sup>+</jats:sup> ) is a coenzyme found in all living cells. It serves both as a critical coenzyme for enzymes that fuel reduction-oxidation reactions, carrying electrons from one reaction to another, and as a cosubstrate for other enzymes such as the sirtuins and poly(adenosine diphosphate–ribose) polymerases. Cellular NAD <jats:sup>+</jats:sup> concentrations change during aging, and modulation of NAD <jats:sup>+</jats:sup> usage or production can prolong both health span and life span. Here we review factors that regulate NAD <jats:sup>+</jats:sup> and discuss how supplementation with NAD <jats:sup>+</jats:sup> precursors may represent a new therapeutic opportunity for aging and its associated disorders, particularly neurodegenerative diseases. </jats:p>

<jats:p>The potential for the gut microbiota to affect health has a particular relevance for older individuals. This is because the microbiota may modulate aging-related changes in innate immunity, sarcopaenia, and cognitive function, all of which are elements of frailty. Both cell culture–dependent and –independent studies show that the gut microbiota of older people differs from that of younger adults. There is no chronological threshold or age at which the composition of the microbiota suddenly alters; rather, changes occur gradually with time. Our detailed analyses have separated the microbiota into groups associated with age, long-term residential care, habitual diet, and degree of retention of a core microbiome. We are beginning to understand how these groups change with aging and how they relate to clinical phenotypes. These data provide a framework for analyzing microbiota-health associations, distinguishing correlation from causation, identifying microbiota interaction with physiological aging processes, and developing microbiota-based health surveillance for older adults.</jats:p>