Two interdependent hallmarks of aging are epigenetic alteration — heritable, non-sequence changes to how DNA is packaged and accessed, effected through histone modification, DNA methylation, and consequent chromatin remodeling — and loss of proteostasis, the failure of a cell's protein quality-control machinery to maintain correct synthesis, folding, and clearance of proteins. The causal principle linking them is that altered chromatin state changes which genes are transcribed and at what rate, so dysregulated gene expression propagates downstream into a dysregulated proteome, whose damaged and misfolded products accumulate to toxic or signal-disrupting effect. This material belongs to the biology of aging (biogerontology) within molecular and cellular biology, extending the genetics-course treatment of epigenetic gene regulation into a time-dependent, environmentally responsive account of organismal decline.
Two interdependent hallmarks of aging are epigenetic alteration — heritable, non-sequence changes to how DNA is packaged and accessed, effected through histone modification, DNA methylation, and cons…