蛋白激酶 B/AKT 通过 NADPH 氧化酶 4 的激活介导胰岛素样生长因子 1 诱导的血管平滑肌细胞组蛋白去乙酰化酶 5 的磷酸化和核输出。

Protein kinase B/AKT mediates insulin-like growth factor 1-induced phosphorylation and nuclear export of histone deacetylase 5 via NADPH oxidase 4 activation in vascular smooth muscle cells.

机构信息

Laboratory of Cellular Signaling, Montreal Diabetes Research Center and Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada.

Department of Pharmacology and Physiology, Faculty of Medicine, University of Montreal, Montreal, Canada.

出版信息

J Cell Physiol. 2019 Aug;234(10):17337-17350. doi: 10.1002/jcp.28353. Epub 2019 Feb 22.

DOI:10.1002/jcp.28353

PMID:30793765

Abstract

Insulin-like growth factor 1 (IGF-1) mediates the generation of reactive oxygen species (ROS) and the activation of growth promoting signaling pathways. Histone deacetylases (HDACs) regulate gene transcription by deacetylating lysine residues in histone and nonhistone proteins and a heightened HDAC activation, notably of HDAC5, is associated with vascular disorders, such as atherosclerosis. Although the contribution of IGF-1 in these pathologies is well documented, its role in HDAC phosphorylation and activation remains unexplored. Here, we examined the effect of IGF-1 on HDAC5 phosphorylation in vascular smooth muscle cells (VSMCs) and identified the signaling pathways involved in controlling HDAC5 phosphorylation and nuclear export. Treatment of A10 VSMCs with IGF-1 enhanced HDAC5 phosphorylation. Blockade of the IGF-1 receptor tyrosine kinase (TK) activity with the specific pharmacological inhibitor, AG1024, significantly inhibited IGF-1-induced HDAC5 phosphorylation, whereas the epidermal growth factor receptor (EGFR) TK antagonist, AG1478, had no effect. Inhibition of the mitogen-activated protein kinase pathway with U0126, SP600125, or SB203580, did not affect HDAC5 phosphorylation, whereas two inhibitors of the phosphoinositide 3-kinase (PI3K)/AKT pathways, wortmannin and SC66, almost completely attenuated IGF-1-induced responses as confirmed by immunoblotting of phospho-HDAC5 and by small interfering RNA (siRNA)-induced AKT silencing. Moreover, the NAD(P)H oxidase (Nox) inhibitor, diphenyleneiodonium (DPI), and Nox4 siRNA, attenuated IGF-1-induced phosphorylation of HDAC5 and AKT. The HDAC5 phosphorylation resulted in its nuclear export, which was reversed by SC66 and DPI. Our results indicate that IGF-1-induced phosphorylation and nuclear export of HDAC5 involve Nox4-dependent ROS generation and PI3K/AKT signaling pathways.

摘要

胰岛素样生长因子 1（IGF-1）介导活性氧（ROS）的生成和促进生长的信号通路的激活。组蛋白去乙酰化酶（HDACs）通过去乙酰化组蛋白和非组蛋白蛋白中的赖氨酸残基来调节基因转录，并且 HDAC 激活度的增加，特别是 HDAC5 的激活度，与血管疾病有关，如动脉粥样硬化。尽管 IGF-1 在这些病理中的作用已有充分的记录，但它在 HDAC 磷酸化和激活中的作用仍未得到探索。在这里，我们研究了 IGF-1 对血管平滑肌细胞（VSMCs）中 HDAC5 磷酸化的影响，并确定了参与控制 HDAC5 磷酸化和核输出的信号通路。用 IGF-1 处理 A10 VSMCs 可增强 HDAC5 的磷酸化。用特异性药理学抑制剂 AG1024 阻断 IGF-1 受体酪氨酸激酶（TK）活性可显著抑制 IGF-1 诱导的 HDAC5 磷酸化，而表皮生长因子受体（EGFR）TK 拮抗剂 AG1478 则没有作用。用 U0126、SP600125 或 SB203580 抑制丝裂原活化蛋白激酶（MAPK）途径不会影响 HDAC5 的磷酸化，而两种磷酸肌醇 3-激酶（PI3K）/AKT 途径抑制剂wortmannin 和 SC66 则几乎完全阻断了 IGF-1 诱导的反应，如通过免疫印迹法检测到的磷酸化 HDAC5 和通过小干扰 RNA（siRNA）诱导的 AKT 沉默来证实。此外，NAD（P）H 氧化酶（Nox）抑制剂二苯碘鎓（DPI）和 Nox4 siRNA 可减弱 IGF-1 诱导的 HDAC5 和 AKT 磷酸化。HDAC5 的磷酸化导致其核输出，SC66 和 DPI 可逆转该过程。我们的结果表明，IGF-1 诱导的 HDAC5 磷酸化和核输出涉及 Nox4 依赖性 ROS 生成和 PI3K/AKT 信号通路。