Impacts of transcriptional regulation on aging and senescence.

The genetic makeup of the organism appears to dictate the species-specific rate of aging and the maximum life-span potential. The genotype is converted to phenotype through transcriptional and translational regulation. A group of gene regulatory proteins (transcription factors) play critical roles in controlling the rates of transcription of specific genes by directly interacting with regulatory sequences at gene promoters. Here, we review the basic mechanism of transcriptional control and the role of a number of transcription factors whose level and/or activity alter with age. Among these age-dependent transcription factors, many are involved in the regulation of stress and inflammatory responses and are subjected to functional alterations by reactive oxygen species (ROSs). A progressive rise of oxidative stress, impaired ability to cope with stressful stimuli and prolongation of the inflammatory response are some of the hallmarks of the senescent phenotype. Results published to date are supportive of the concept that a species-specific program of the temporal regulation of genes with additional modulation by a number of epigenetic factors, mediates the age-dependent deterioration of physiological functions and development of the senescent phenotype.