Transcriptional memory in skeletal muscle. Don't forget (to) exercise

Abstract

Transcriptional memory describes an ancient and highly conserved form of cellular learning that enables cells to benefit from recent experience by retaining a mitotically inheritable but reversible memory of the initial transcriptional response when encountering an environmental or physiological stimulus. Herein, we will review recent progress made in the understanding of how cells can make use of diverse constituents of the epigenetic toolbox to retain a transcriptional memory of past states and perturbations. Specifically, we will outline how these mechanisms will help to improve our understanding of skeletal muscle plasticity in health and disease. We describe the epigenetic road map that allows skeletal muscle fibers to navigate through training‐induced adaptation processes, and how epigenetic memory marks can preserve an autobiographical history of lifestyle behavior changes, pathological challenges, and aging. We will further consider some key findings in the field of exercise epigenomics to emphasize major challenges when interpreting dynamic changes in the chromatin landscape in response to acute exercise and training.

Tissue Expression of Methyltransferases in Response to Acute and Long-term Exercise in Sedentary Men

“…Notably, PRMTs are also involved in arginine methylation of histones 19 , and the GO enrichment analyses thus collectively suggest differential methylation of speci c histone amino acid residues just after exercise. These results may aid future research in identifying more targeted approaches in studying the role of epigenetic modi cations in SkM during exercise 29,33,34 , and we note that differential expression largely involved histone methyltransferases and not DNA methyltransferases.…”

Epigenetic impact of the parents' physical activity on the health of their children

“…CpG islands mainly co-localize with promoters and transcription start sites. Unlike the vast majority of CpGs located in the intergenic regions and repetitive elements, CpG islands are typically unmethylated regardless of the transcriptional activity of a neighboring genebut if they become hypermethylated, they promote gene silencing [23]. While CpG methylation at transcription start sites is generally associated with gene silencing, recent studies have shown that DNA methylationif it is in the gene bodymay be positively correlated with gene transcription and have its impact on the occurrence of alternative splicing [24].…”

“…Conversely, deacetylation of histones correlates with transcriptional silencing and the heterochromatic state [21]. Not only does histone acetylation facilitate destabilization of DNA-nucleosome interactions for active transcription, but-when provoked on a global scale-it promotes rearrangements in the three-dimensional genome architecture, thus enabling extensive translocation of genomic loci and regulatory regions to a nuclear pore complex [23,33]. Some epigenetic modifications directly affect the cognitive functions of the body and are associated with better results in learning tests and a better memory [34] for example with the very phenomenon of histone acetylation that is directly related to active transcription and the establishment of a long-term memory [35].…”

A Summer Issue to hopefully take with you on holiday

“…Epigenetics is defined as non-sequence structural modifications of DNA and/ or histones that alter patterns of gene expression, and diverse environmental stimuli can provoke epigenetic responses in many different cell types that can last for decades, and even be transferred to offspring, one example being maternal nutritional status (Vineis et al, 2017). Current evidence also supports a long-lasting exercise-induced epigenetic memory in skeletal muscle (Beiter et al, 2020), whereby previous strength training, leading to long-lasting changes in DNA methylation patterns, aided future muscle mass gains in humans. Thus, all environmental stimuli that can lead to shortterm cellular adaptation can lead to epigenetic imprinting that bear the potential of a longterm cellular memory.…”