Activation and expression of endogenous CREB-regulated transcription coactivators (CRTC) 1, 2 and 3 in the rat adrenal gland.
Activation and expression of endogenous CREB-regulated transcription coactivators (CRTC) 1, 2 and 3 in the rat adrenal gland.
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DOI：
10.1111/jne.12920
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发表时间：
2021-01
影响因子：
3.2
通讯作者：
Spiga F
中科院分区：
文献类型：
--
作者：
Smith LIF;Zhao Z;Walker J;Lightman S;Spiga F
cAMP 反应元件结合蛋白 (CREB) 调节的转录共激活因子 (CRTC)2 的激活和核转位发生在大鼠肾上腺中，响应促肾上腺皮质激素 (ACTH) 和应激源，并且与类固醇生成急性调节蛋白 (StAR) 的转录调节有关。我们最近证明了 CRTC 亚型 CRTC1 和 CRTC3 在肾上腺皮质细胞系中的激活。在本研究中，我们的目的是确定在基础条件下和强烈的内毒素应激挑战后，三种 CRTC 亚型在体内与 Star 转录相关的激活和表达。静脉注射后收集大鼠肾上腺和血浆。给予超电大小的 ACTH 脉冲或给予脂多糖，以及在 24 小时内无压力的条件下。测量血浆 ACTH 和皮质酮 (CORT)，处理肾上腺以通过蛋白质免疫印迹测量蛋白质，通过定量逆转录聚合酶链反应测量 RNA，并通过染色质免疫沉淀测量 CRTC2 和 CRTC3 与 Star 启动子的关联。 CRTC2 和 CRTC3 的核定位增加伴随着超电和内毒素应激诱导的血浆 ACTH 的增加，这与 CREB 磷酸化的增加和 Star 转录的相应增加有关。 CRTC2 和 CRTC3 均被证明与 Star 启动子相关，CRTC3 结合的动态与核蛋白水平的变化相对应。尽管发现了内毒素应激后长期下调的证据，但 CRTC 亚型的超电表达或 24 小时内的变化几乎没有变化。我们得出的结论是，共转录因子 CRTC2，更清楚地说，CRTC3 似乎与磷酸化 CREB 一起作用，产生 Star 转录的超电脉冲，这对于维持基础 StAR 表达至关重要。同样，我们的研究结果表明，CRTC2 和 CRTC3 在内毒素应激源后介导 Star 转录起始；然而，其他转录因子可能是肾上腺星转录长期上调的原因。本研究旨在确定与促肾上腺皮质激素（ACTH）诱导的类固醇生成急性调节（StAR）转录相关的三种cAMP反应元件结合蛋白（CREB）调节的转录共激活子（CRTC）亚型的体内激活和表达动态。 CRTC2 和 CRTC3 在 Star 启动子处的核定位和关联遵循超电和内毒素应激活动诱导的血浆 ACTH 增加。与 CREB 磷酸化的增加和 Star 转录的增加相对应，我们得出结论，CRTC2 和 CRTC3 似乎与磷酸化的 CREB 一起在 Star 转录的起始中发挥共转录因子的作用。
The activation and nuclear translocation of cAMP‐response element binding protein (CREB)‐regulated transcription coactivator (CRTC)2 occurs in the rat adrenal gland, in response to adrenocorticotrophic hormone (ACTH) and stressors, and has been implicated in the transcriptional regulation of steroidogenic acute regulatory protein (StAR). We have recently demonstrated the activation of CRTC isoforms, CRTC1 and CRTC3, in adrenocortical cell lines. In the present study, we aimed to determine the activation and expression of the three CRTC isoforms in vivo in relation to Star transcription, under basal conditions and following a robust endotoxic stress challenge. Rat adrenal glands and blood plasma were collected following i.v. administration of either an ultradian‐sized pulse of ACTH or administration of lipopolysaccharide, as well as under unstressed conditions across the 24‐hour period. Plasma ACTH and corticosterone (CORT) were measured and the adrenal glands were processed for measurement of protein by western immunoblotting, RNA by a quantitative reverse transcriptase‐polymerase chain reaction and association of CRTC2 and CRTC3 with the Star promoter by chromatin immunoprecipitation. An increase in nuclear localisation of CRTC2 and CRTC3 followed increases in both ultradian and endotoxic stress‐induced plasma ACTH, and this was associated with increased CREB phosphorylation and corresponding increases in Star transcription. Both CRTC2 and CRTC3 were shown to associate with the Star promoter, with the dynamics of CRTC3 binding corresponding to that of nuclear changes in protein levels. CRTC isoforms show little variation in ultradian expression or variation across 24 hours, although evidence of long‐term down‐regulation following endotoxic stress was found. We conclude that co‐transcription factors CRTC2 and, more clearly, CRTC3 appear to act alongside phosphorylated CREB in the generation of ultradian pulses of Star transcription, essential for the maintenance of basal StAR expression. Similarly, our findings suggest CRTC2 and CRTC3 mediate Star transcriptional initiation following an endotoxic stressor; however, other transcription factors are likely to be responsible for the long‐term up‐regulation of adrenal Star transcription. The present study aimed to determine the in vivo dynamics of activation and expression of the three cAMP‐response element binding protein (CREB)‐regulated transcription coactivator (CRTC) isoforms in relation to adrenocorticotrophic hormone (ACTH)‐induced steroidogenic acute regulatory (StAR) transcription. Nuclear localisation and association of CRTC2 and CRTC3 at the Star promoter followed increases in plasma ACTH induced by ultradian and endotoxic stress activity. Corresponding with increased CREB phosphorylation and increases in Star transcription, we conclude that CRTC2 and CRTC3 appear to play a role as co‐transcription factors alongside phosphorylated CREB in the initiation of Star transcription.
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DOI：
10.1073/pnas.1712616114
发表时间：
2017-10-01
影响因子：
11.1
作者：
Kim, Jeong-Ho;Hedrick, Susan;Montminy, Marc
通讯作者：
Montminy, Marc
影响因子：
4.8
作者：
Liu, Ying;Coello, Ana G.;Aguilera, Greti
通讯作者：
Aguilera, Greti
影响因子：
9.2
作者：
Bittinger, MA;McWhinnie, E;Labow, M
通讯作者：
Labow, M
影响因子：
16.6
作者：
Han HS;Choi BH;Kim JS;Kang G;Koo SH
通讯作者：
Koo SH
影响因子：
4.1
作者：
Liu, Ying;Smith, Lorna I.;Aguilera, Greti
通讯作者：
Aguilera, Greti