-Thota Kanishka Rao, Amity University Kolkata
Skeletal muscle is one of the three major muscle types, composed of skeletal muscle tissue which is under the voluntary control of the somatic system. Maintaining muscle mass and performance into older age is prime for human health-span and quality of life. Five to ten per cent of older adults have sarcopenia, which is caused by reductions in muscle mass and strength. This loss of muscle mass and strength ends up in frailty, increased incidence of falls, hospitalisation and morbidity.
A primary hallmark of ageing is that the alteration of the epigenetic landscape. Epigenetics encompasses all kinds of lifestyle factors and their modifications to DNA and histones, without changes to the inherited DNA sequence. DNA methylation in aged skeletal muscle occurs at tissue-specific genes and is the most studied epigenetic modification and involves the addition of a covalent methyl group to the 5′ position of the pyrimidine ring of cytosine.
Increased methylation (hypermethylation) to cytosine–guanine (C–G) pairings (CpG sites), especially in CpG-rich regions like gene promoters, typically ends up in reduced capacity for the transcriptional apparatus to bind those regions, suppressing natural phenomenon. Methylated CpG islands in promoters also end up in decent compaction of adjacent chromatin via the recruitment of chromatin-modifying protein/protein-complexes, further silencing organic phenomenon. In contrast, reduced methylation (hypomethylation) provides a more favourable DNA landscape for the transcriptional apparatus to bind those regions, likewise as more relaxed chromatin, enabling gene expression to occur.
Source:
Turner, D.C., Gorski, P.P., Maasar, M.F. et al. DNA methylation across the genome in aged human skeletal muscle tissue and muscle-derived cells: the role of HOX genes and physical activity. Sci Rep 10, 15360 (2020).
https://doi.org/10.1038/s41598-020-72730-z
Visit https://bioxone.in// for more updates.
Very much informative article ????♥️