Molecular advances of the past decade have led to the discovery of a myriad of 'aging genes' (methuselah, Indy, InR, Chico, superoxide dismutase) that extend Drosophila lifespan by up to 85%. Despite this life extension, these mutants are no longer lived than at least some recently wild-caught strains. Typically, long-lived mutants are identified in relatively short-lived genetic backgrounds, and their effects are rarely tested in genetic backgrounds other than the one in which they were isolated or derived.
The pivotal role played by zinc-gene interaction in affecting the inflammatory response mediated by IL-6 in ageing, successful ageing (nonagenarians) and the most common age-related diseases is now recognized. Contradictory data emerging from association studies of IL-6 polymorphisms with longevity and chronic age-related diseases seem to arise from the interaction of this inflammatory pathway with dietary habits. Similar conclusions are expected to arise from association studies with the frailty syndrome.
Epigenetics is the study of the variations of genetic expression that occur not because of differences in DNA structure, but because of chromatin alternations that modulate DNA transcription. The mechanisms of epigenetics are thus the link between genome and phenotype. This article will explore the best known epigenetic mechanisms, namely DNA methylation and histone modifications and how they may lead to the emergence of depression and schizophrenia. The practical interest of this research is an understanding of the role of early interactions in the development of mental illness.
Journal of Psychosocial Nursing and Mental Health Services
Understanding pharmacogenetic differences in drug response and tolerability has been an important area of research in personalized medicine, but the clinical utility of pharmacogenetics testing has not been established. Identification of genetic polymorphisms due to single nucleotide polymorphisms is the most common approach, but this does not take into account the potential relevance of copy number variants, noncoding RNA gene regulation, gene-gene and gene-interactions, and epigenetic modifications, which increase the complexity of pharmacogenomics research.
The genetic regulation of the human epigenome is not fully appreciated. Here we describe the effects of genetic variants on the DNA methylome in human lung based on methylation-quantitative trait loci (meQTL) analyses. We report 34,304 cis- and 585 trans-meQTLs, a genetic-epigenetic interaction of surprising magnitude, including a regulatory hotspot. These findings are replicated in both breast and kidney tissues and show distinct patterns: cis-meQTLs mostly localize to CpG sites outside of genes, promoters and CpG islands (CGIs), while trans-meQTLs are over-represented in promoter CGIs.
Epidemiological studies have shown significant results in the interaction between the functions of brain-derived neurotrophic factor (BDNF) and 5-HT in mood disorders, such as major depressive disorder (MDD). The latest research has provided convincing evidence that gene transcription of these molecules is a target for epigenetic changes, triggered by stressful stimuli that starts in early childhood and continues throughout life, which are subsequently translated into structural and functional phenotypes culminating in depressive disorders.
Virtually all psychiatric traits are genetically complex. This article discusses the genetics of complex traits in psychiatry. The complexity is accounted for by numerous factors, including multiple risk alleles, epistasis, and epigenetic effects such as methylation. Risk alleles can individually be common or rare, and can include, for example, single nucleotide polymorphisms and copy number variants that are transmitted or are new mutations, and other kinds of variation.
Measurements derived from neuroimaging data can serve as markers of disease and/or healthy development, are largely heritable, and have been increasingly utilized as (intermediate) phenotypes in genetic association studies. To date, imaging genetic studies have mostly focused on discovering isolated genetic effects, typically ignoring potential interactions with non-genetic variables such as disease risk factors, environmental exposures, and epigenetic markers.
Emotion perception has been extensively studied in cognitive neurosciences and stands as a promising intermediate phenotype of social cognitive processes and psychopathologies. Exciting imaging genetic studies have recently identified genetic and epigenetic variants affecting brain responses during emotion perception tasks, but characterizing how these variants interact and relate to higher-order cognitive processes remains a challenge. Here, we integrate works in parallel fields and propose a new psychophysical conceptualization to address this issue.
We define neurodevelopment as the dynamic inter-relationship between genetic, brain, cognitive, emotional and behavioural processes across the developmental lifespan. Significant and persistent disruption to this dynamic process through environmental and genetic risk can lead to neurodevelopmental disorders and disability. Research designed to ameliorate neurodevelopmental disorders in low- and middle-income countries, as well as globally, will benefit enormously from the ongoing advances in understanding their genetic and epigenetic causes, as modified by environment and culture.