Glucocorticoids rapidly inhibit cell migration through a novel, non-transcriptional HDAC6 pathway

Abstract

Glucocorticoids (GCs) act through the glucocorticoid receptor (GR) to regulate immunity, energy metabolism, and tissue repair. Upon ligand binding, activated GR mediates cellular effects by regulating gene expression, but some GR effects can occur rapidly without new transcription. We show GCs rapidly inhibit cell migration, in response to both GR agonist and antagonist ligand binding. The inhibitory effect on migration is prevented by GR knockdown with siRNA, confirming GR specificity, but not by actinomycin D treatment, suggesting a non-transcriptional mechanism. We identified a rapid onset increase in microtubule polymerisation following glucocorticoid treatment, identifying cytoskeletal stabilisation as the likely mechanism of action. HDAC6 overexpression, but not knockdown of αTAT1, rescued the GC effect, implicating HDAC6 as the GR effector. Consistent with this hypothesis, ligand-dependent cytoplasmic interaction between GR and HDAC6 was demonstrated by quantitative imaging. Taken together, we propose that activated GR inhibits HDAC6 function and thereby increases the stability of the microtubule network to reduce cell motility. We therefore report a novel, non-transcriptional mechanism whereby GCs impair cell motility through inhibition of HDAC6 and rapid reorganization of the cell architecture.

Nuclear oligo hashing improves differential analysis of single-cell RNA-seq

“…14 ). Unresponsive genes also included G-protein coupled receptors associated with cytoskeleton reorganization, concordant with previous reports of HDAC inhibition preventing glucocorticoid-induced hypertension 51 and changes in microtubule dynamics 52 . Interestingly, we observed various classes of effects on these unresponsive genes suggesting multiple ways in which HDACi might interfere with the DEX response (Supplementary Fig.…”

HNF4A modulates glucocorticoid action in the liver

“…NR3C1, the glucocorticoid receptor (GR), is an almost ubiquitously expressed nuclear receptor. While there is evidence for rapid, non-genomic actions of glucocorticoids ( Dallman, 2005 ; Kershaw et al., 2020 ), the chief outcomes of GR activation occur through its nuclear activity. GR binds the genome through the glucocorticoid response element (GRE) motif, which comprises two palindromic hexamers separated by a 3 bp spacer (AGAACANNNTGTTCT).…”

HNF4A is required to specify glucocorticoid action in the liver

“…NR3C1, the glucocorticoid receptor (GR), is an almost ubiquitously expressed nuclear receptor. Whilst there is evidence for rapid, non-genomic actions of glucocorticoids (1,2), the chief outcomes of GR activation occur through its nuclear activity. GR binds the genome through the glucocorticoid response element (GRE) motif, which comprises two palindromic hexamers separated by a 3bp spacer (AGAA-CANNNTGTTCT).…”