Glucocorticoids (GCs) act through the glucocorticoid receptor (GR, also known as NR3C1) 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. Here, we show that 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 GC 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.

This article has an associated First Person interview with the first author of the paper.

糖皮质激素（GC）通过糖皮质激素受体（GR，也称为 NR3C1）发挥作用，调节免疫、能量代谢和组织修复。配体结合后，激活的 GR 通过调节基因表达来介导细胞效应，但某些 GR 效应可以在没有新转录的情况下迅速发生。在这里，我们发现 GC 响应 GR 激动剂和拮抗剂配体结合而快速抑制细胞迁移。siRNA 的 GR 敲低可以阻止对迁移的抑制作用，证实了 GR 特异性，但放线菌素 D 处理则不能阻止这种作用，这表明存在非转录机制。我们发现 GC 处理后微管聚合迅速增加，确定细胞骨架稳定是可能的作用机制。HDAC6 过表达（而非 αTAT1 敲低）挽救了 GC 效应，表明 HDAC6 是 GR 效应子。与这一假设一致，定量成像证实了 GR 和 HDAC6 之间配体依赖性细胞质相互作用。综上所述，我们认为激活的 GR 会抑制 HDAC6 功能，从而增加微管网络的稳定性，从而降低细胞运动性。因此，我们报告了一种新颖的非转录机制，GC 通过抑制 HDAC6 和细胞结构的快速重组来损害细胞运动。

本文有对该论文第一作者的相关第一人称采访。