Epigenetics and nutrition

In the last few years, the idea of food and nutrition has undergone radical changes. The paradigm defining food as a simple source of energy and body mass has evolved in a novel concept, in which nutrients can exert specific functions directly linked to human health. Several edibles contain biological active compounds that influence cellular, metabolic and physiologic processes. A variety of dietary compounds have been associated with specific effects and mechanisms of action, often involving epigenetic modifications and gene expression changes. DNA methylation, histone modifications and the activity of non-coding RNAs control chromatin condensation state, allowing the interaction of DNA with transcription factors required for transcriptional activation. Some metabolites act as substrates of key chromatin remodeling factors or compete with other substrates, influencing their catalytic activity. The quantity and quality of macronutrients assumed by diet offers a possible mechanism of interaction between the body and its environment. A number of biological compounds are known to interact with the epigenome. Folic acid, methionine, choline and other B group vitamins are an important source of one-carbon groups required for methylation of histone proteins and non-histone chromatin remodeling factors. Other compounds like polyphenols, including resveratrol, curcumin and quercetin exert a multitude of biological activities. Furthermore, these compounds can influence DNA methyltransferases, the enzymes responsible for DNA methylation. Dietary interventions aimed to maximize potential health benefits derived from nutrition have shown that dietary regimens can be very effective for prevention and treatment of several diseases. Calorie restriction, protein restriction, fast mimicking diets or time restricted feeding have shown to have significant effects on health. Food quality is crucial for the activity of biological compounds and their potential health benefits. Diets rich in animal-derived proteins are associated with higher rates of mortality compared to diets based on plant-derived proteins

Control of reproductive floral organ identity specification in Arabidopsis by the C function regulator AGAMOUS

The floral organ identity factor AGAMOUS (AG) is a key regulator of Arabidopsis thaliana flower development, where it is involved in the formation of the reproductive floral organs as well as in the control of meristem determinacy. To obtain insights into how AG specifies organ fate, we determined the genes and processes acting downstream of this C function regulator during early flower development and distinguished between direct and indirect effects. To this end, we combined genome-wide localization studies, gene perturbation experiments, and computational analyses. Our results demonstrate that AG controls flower development to a large extent by controlling the expression of other genes with regulatory functions, which are involved in mediating a plethora of different developmental processes. One aspect of this function is the suppression of the leaf development program in emerging floral primordia. Using trichome initiation as an example, we demonstrate that AG inhibits an important aspect of leaf development through the direct control of key regulatory genes. A comparison of the gene expression programs controlled by AG and the B function regulators APETALA3 and PISTILLATA, respectively, showed that while they control many developmental processes in conjunction, they also have marked antagonistic, as well as independent activities

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