Abstract
The epigenetic revolution has led to a paradigm shift in our understanding of gene regulation and function. Epigenetic modifications, including DNA methylation, posttranslational histone modifications, and regulatory noncoding RNAs, display unique features, such as reversibility and transgenerational inheritance. A great variety of environmental and lifestyle factors can cause changes in the epigenome. Epigenetic alterations can contribute to the underlying mechanisms of human diseases including cancer, cardiovascular, neurological, psychiatric, autoimmune, metabolic and inherited. The chapter focuses on the fine interplay between environmental stress, the epigenetic adaptive responses, and how the inability to adapt may trigger disease outcomes. A model of the epigenetic disease is postulated, epigenetic disease adaptational model (EDAM), according to which the epigenetic disease develops as a failure to adapt to environmental stressors. This may occur in at least two possible scenarios: (1) when the epigenetic adaptational programs are not adequate to stress nature, duration, intensity and/or stage of action and (2) when the epigenetic adaptational programs are not adequate to the situation. In the second scenario, the stressful situation is wrongly considered the most feasible situation, and the stressful conditions are taken as “norm.” The proposed model highlights important topics for future research in the field of epigenetics and disease.