Bartlett A A, DeRosa H, Clark M, Lapp H E, Guffanti G, Hunter R G
University of Massachusetts Boston, 100 Morrissey Blvd, Boston, MA, 02125, USA.
McLean Hospital, Harvard Medical School, 115 Mill St, Belmont, MA, 02478, USA.
Neurobiol Stress. 2021 Sep 13;15:100397. doi: 10.1016/j.ynstr.2021.100397. eCollection 2021 Nov.
The hippocampus is a highly plastic brain region sensitive to environmental stress. It shows dynamic changes in epigenetic marks associated with stress related learning. Previous work has shown that acute stress induces substantial transient changes in histone H3 lysine 9 trimethylation (H3K9me3). Moreover, increased H3K9me3 is enriched in hippocampal gene deserts accumulating within endogenous retroviruses and transposable elements. We have found that in response to acute glucocorticoid treatment, a similar change in global H3K9me3 is observed. However, when localized we found that H3K9me3 is markedly decreased at B2 short interspersed nuclear elements but not within intracisternal-A particle endogenous retroviruses. Further, decreased H3K9me3 valence within B2 elements was associated with increased transcript abundance. These data demonstrate the capacity for acute glucocorticoids to mobilize transposable elements via epigenetic unmasking. Reconciled with previous findings following acute stress, this suggests the capacity for mobile elements to potentially function as novel regulators given their dynamic regulation by stress and glucocorticoids.
海马体是一个对环境压力敏感的高度可塑性脑区。它在与应激相关学习有关的表观遗传标记中表现出动态变化。先前的研究表明，急性应激会诱导组蛋白H3赖氨酸9三甲基化（H3K9me3）发生大量短暂变化。此外，增加的H3K9me3富集于内源性逆转录病毒和转座元件内积累的海马体基因荒漠中。我们发现，在急性糖皮质激素处理后，观察到全局H3K9me3有类似变化。然而，当进行局部观察时，我们发现H3K9me3在B2短散在核元件处明显减少，但在A颗粒内源性逆转录病毒内并未减少。此外，B2元件内H3K9me3效价的降低与转录本丰度的增加有关。这些数据证明了急性糖皮质激素通过表观遗传去掩盖来动员转座元件的能力。与急性应激后的先前发现相一致，这表明鉴于转座元件受应激和糖皮质激素的动态调控，它们有可能作为新型调节因子发挥作用。
