Chromatin: the old and young of it

Abstract

Aging affects nearly all aspects of our cells, from our DNA to our proteins to how our cells handle stress and communicate with each other. Age-related chromatin changes are of particular interest because chromatin can dynamically respond to the cellular and organismal environment, and many modifications at chromatin are reversible. Changes at chromatin occur during aging, and evidence from model organisms suggests that chromatin factors could play a role in modulating the aging process itself, as altering proteins that work at chromatin often affect the lifespan of yeast, worms, flies, and mice. The field of chromatin and aging is rapidly expanding, and high-resolution genomics tools make it possible to survey the chromatin environment or track chromatin factors implicated in longevity with precision that was not previously possible. In this review, we discuss the state of chromatin and aging research. We include examples from yeast, Drosophila, mice, and humans, but we particularly focus on the commonly used aging model, the worm Caenorhabditis elegans, in which there are many examples of chromatin factors that modulate longevity. We include evidence of both age-related changes to chromatin and evidence of specific chromatin factors linked to longevity in core histones, nuclear architecture, chromatin remodeling, and histone modifications.

The serum small non‐coding RNA (SncRNA) landscape as a molecular biomarker of age associated muscle dysregulation and insulin resistance in older adults

“…Age‐associated changes within the different populations of ncRNAs may suggest crosstalk between sncRNA subtypes to modify cellular communication and cell specific signaling pathways associated with ageing, akin to those observed between long non‐coding RNAs (lncRNAs) and miRNAs of which lncRNAs act as miRNA sponges, modulating its availability to endogenous mRNA targets. 58 , 59 Combining available gene targets for the age associated sncRNAs revealed the top pathways enriched amongst the combined age associated sncRNAs included chromatin organization, WNT signaling, cellular response to stress, and oncogene induced senescence, pathways implicated in ageing across a range of cell types, 60 , 61 , 62 , 63 , 64 suggesting that the circulating sncRNA signature may reflect the ageing process observed within cells.…”

How Chromatin Motor Complexes Influence the Nuclear Architecture: A Review of Chromatin Organization, Cohesins, and Condensins with a Focus on C. elegans

“…These holocentric chromosomes lack a single point centromere and instead have kinetochore attachments along the entire length of the chromosomes [79]. Despite this difference, C. elegans chromosomes follow principles of chromatin organization during interphase seen in other species [80]. Therefore, this section will highlight chromatin organization during cell division in the context of C. elegans while also identifying those mechanisms unique to C. elegans.…”