Nutritional Epigenetics: How Metabolism Epigenetically Controls Cellular Physiology, Gene Expression and Disease

The interplay of metabolic and epigenetic players in disease development

Epigenetic modifications and their alterations can cause variation in gene expression patterns which can ultimately affect a healthy individual. Until a few years ago, it was thought that the epigenome affects the transcriptome which can regulate the proteome and the metabolome. Recent studies have shown that the metabolome independently also plays a major role in regulating the epigenome bypassing the need for transcriptomic control. Alternatively, an imbalanced metabolome, stemming from transcriptome abnormalities, can further impact the transcriptome, creating a self-perpetuating cycle of interconnected occurrences. As a result, external factors such as nutrient intake and diet can have a direct impact on the metabolic pools and its reprogramming can change the levels and activity of epigenetic modifiers. Thus, the epigenetic landscape steers toward a diseased condition. In this review, we have discussed how different metabolites and dietary patterns can bring about changes in different arms of the epigenetic machinery such as methylation, acetylation as well as RNA mediated epigenetic mechanisms. We checked for limiting metabolites such as αKG, acetyl-CoA, ATP, NAD+, and FAD, whose abundance levels can lead to common diseases such as cancer, neurodegeneration etc. This gives a clearer picture of how an integrated approach including both epigenetics and metabolomics can be used for therapeutic purposes.

The Interplay between Dysregulated Metabolism and Epigenetics in Cancer

Cellular metabolism (or energetics) and epigenetics are tightly coupled cellular processes. It is arguable that of all the described cancer hallmarks, dysregulated cellular energetics and epigenetics are the most tightly coregulated. Cellular metabolic states regulate and drive epigenetic changes while also being capable of influencing, if not driving, epigenetic reprogramming. Conversely, epigenetic changes can drive altered and compensatory metabolic states. Cancer cells meticulously modify and control each of these two linked cellular processes in order to maintain their tumorigenic potential and capacity. This review aims to explore the interplay between these two processes and discuss how each affects the other, driving and enhancing tumorigenic states in certain contexts.

Nutriepigenomics in Environmental-Associated Oxidative Stress

Complex molecular mechanisms define our responses to environmental stimuli. Beyond the DNA sequence itself, epigenetic machinery orchestrates changes in gene expression induced by diet, physical activity, stress and pollution, among others. Importantly, nutrition has a strong impact on epigenetic players and, consequently, sustains a promising role in the regulation of cellular responses such as oxidative stress. As oxidative stress is a natural physiological process where the presence of reactive oxygen-derived species and nitrogen-derived species overcomes the uptake strategy of antioxidant defenses, it plays an essential role in epigenetic changes induced by environmental pollutants and culminates in signaling the disruption of redox control. In this review, we present an update on epigenetic mechanisms induced by environmental factors that lead to oxidative stress and potentially to pathogenesis and disease progression in humans. In addition, we introduce the microenvironment factors (physical contacts, nutrients, extracellular vesicle-mediated communication) that influence the epigenetic regulation of cellular responses. Understanding the mechanisms by which nutrients influence the epigenome, and thus global transcription, is crucial for future early diagnostic and therapeutic efforts in the field of environmental medicine.