Epigenetic engineering and its possible role in anti-aging intervention.

Recently a cluster of new hypotheses of aging has been suggested, which explicitly predict the importance of early-life events in health and life span modulations. It has been widely assumed that these long-lasting consequences of early-life exposures may depend on the same mechanisms as those underlying "cellular memory," that is, epigenetic inheritance systems. There is a growing body of evidence that environmentally induced perturbations in the epigenetic processes (which involve alterations of gene expression without a change in DNA sequence) can determine different aspects of aging, as well as etiology and pathogenesis of age-related diseases. Long-term beneficial effects can also occur under some conditions. Changes in gene expression were detected by the life-extending hormetic interventions, such as irradiation, both heat and cold shocks, repeated mild heat stress, dietary restriction, and hypergravity, as well as by geroprotectors (e.g., antioxidants). It might be hypothesized that life-extending effects are most likely a consequence of unspecific (hormetic) action, rather than specific (geroprotective) action, and induced transcriptional changes may be a common mechanism for all anti-aging treatments. The epigenetic interventions (e.g., pre- and postnatal mild stresses), it seems, can be specifically useful in the modulation of aging processes and healthy life extension.