Epigenetic transcriptional memory

Abstract

Organisms alter gene expression to adapt to changes in environmental conditions such as temperature, nutrients, inflammatory signals and stress (Gialitakis et al. 2010; Conrath 2011; Avramova 2015; Solé et al. 2015; Ho and Gasch 2015; Bevington et al. 2016; Hilker et al. 2016). In some cases, organisms can “remember” a previous environmental condition and adapt to that condition more rapidly in the future (Gems and Partridge 2008). Epigenetic transcriptional memory in response to a previous stimulus can produce heritable changes in the response of an organism to the same stimulus, quantitatively or qualitatively altering changes in gene expression (Brickner et al. 2007; Light et al. 2010; Light et al. 2013; D'Urso and Brickner 2014; Avramova 2015; D'Urso et al. 2016). The role of chromatin changes in controlling binding of poised RNAPII during memory are conserved from yeast to humans. Here we discuss epigenetic transcriptional memory in different systems and our current understanding of its molecular basis. Our recent work with a well-characterized model for transcriptional memory demonstrated that memory is initiated by binding of a transcription factor, leading to essential changes in chromatin structure and allowing binding of a poised form of RNA polymerase II, promoting the rate of future re-activation (D'Urso et al. 2016).

Chromatin priming elements establish immunological memory in T cells without activating transcription

“…There are numerous previous studies in plants and animals that defined hit‐and‐run mechanisms which reprogram loci for transcriptional activation . We suspected that similar mechanisms might be at work in memory T cells and, therefore, used mouse T cell models to investigate this.…”

Human umbilical artery endothelial cells from Large‐for‐Gestational‐Age newborn have increased antioxidant efficiency and gene expression

“…Remarkably, LGA-HUAEC showed overexpression of GPX1 mRNA in response to H 2 O 2 treatment, compared with control, resembling the Epigenetic Transcriptional Memory (ETM) described in immune cells exposed to inflammatory mediators (D´Urso & Brickner, 2016;Gialitakis, Arampatzi, Makatounakis, & Papamatheakis, 2010). The ETM has been defined as an inducible gene overexpression when the same gene has been previously exposed to the same stimuli (Gialitakis et al, 2010;Light et al, 2013) If we consider the previously reported pro-oxidant environment in LGA fetuses from women with pregestational obesity (Catalano & Shankar, 2017;Malti et al, 2014), it is reasonable to ponder that oxidative response genes in LGA-derived HUAEC have been chronically stimulated during pregnancy, causing an epigenetic effect that can be mitotically inherited to cellular progeny.…”

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

“…Retaining an epigenetic memory of past incidents is an efficient strategy of eukaryotic organisms to quantitatively and qualitatively adapt transcriptional responses after repeated encounters with the initial stimulus (D'Urso & Brickner, 2017). This “transcriptional memory” was initially described in yeast cells that, once fed with galactose instead of glucose, can remember this metabolic challenge and reactivate genes for galactose conversion more rapidly when encountering galactose again (Kundu, Horn, & Peterson, 2007).…”