SYNCRIP-Dependent Nox2 mRNA Destabilization Impairs ROS Formation in M2-Polarized Macrophages
SYNCRIP-Dependent Nox2 mRNA Destabilization Impairs ROS Formation in M2-Polarized Macrophages
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DOI：
10.1089/ars.2013.5760
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发表时间：
2014-12-20
影响因子：
6.6
通讯作者：
von Knethen, Andreas
中科院分区：
文献类型：
--
作者：
Kuchler, Laura;Giegerich, Annika Klara;von Knethen, Andreas
目的：在脓毒症期间，巨噬细胞与凋亡细胞(ACS)或其分泌产物接触时，可交替激活为M2样表型。同时，NADPH氧化酶依赖的活性氧物种(ROS)的形成被减弱，从而导致免疫瘫痪。然而，确切的机制仍然难以捉摸。在这里，我们提供了NADPH氧化酶NOX2在巨噬细胞M2极化上的mRNA稳定性降低的机制见解，从而减少了脓毒症中ROS的形成。结果：小鼠J774A.1巨噬细胞经凋亡T细胞条件培养液(CM)刺激后，NOX2基因和蛋白表达减少，ROS生成减少。MRNA下拉结合质谱分析鉴定了NOX2 mRNA 3‘非翻译区(3’UTR)上的RNA结合蛋白SYNCRIP。用CM处理凋亡T细胞后，SYNCRIP与NOX2基因3‘端非编码区的结合减弱，随后NOX2基因失稳。在盲肠结扎和穿孔等多菌败血症的体内模型中，SYNCRIP表达显著下调，这与腹膜巨噬细胞中NOX2的表达减少有关。创新：在与ACS物质接触后，巨噬细胞中SYNCRIP的下调破坏了NOX2 mRNA的稳定，并损害了ROS的形成，从而促进了脓毒症中巨噬细胞M2表型的转变。结论：脓毒症大鼠巨噬细胞M2极化导致与NOX2基因3‘非编码区的SYNCRIP结合减弱，破坏了NOX2基因的丰度和表达。因此，对抗反复感染所需的ROS形成受到损害。综上所述，SYNCRIP调控的NOX2 mRNA降解参与了脓毒症的低炎性阶段。抗氧化剂。氧化还原信号。21,2483-2497。
Aims: During sepsis, macrophages are alternatively activated toward an M2-like phenotype on contact with apoptotic cells (ACs) or their secretion products. Simultaneously, NADPH oxidase-dependent reactive oxygen species (ROS) formation is attenuated, thus contributing to immune paralysis. However, the exact mechanism remains elusive. Here, we provide mechanistic insights into diminished mRNA stability of the NADPH oxidase Nox2 on macrophage M2 polarization and therefore reduced ROS formation in sepsis. Results: Murine J774A.1 macrophages were stimulated with conditioned medium (CM) of apoptotic T cells, which reduced Nox2 mRNA and protein expression, consequently decreasing ROS production. An mRNA pulldown approach coupled to mass spectrometry analysis identified the RNA-binding protein SYNCRIP attached to the Nox2 mRNA 3 ' untranslated region (3 ' UTR). The binding of SYNCRIP to the 3 ' UTR of Nox2 mRNA is attenuated after treatment with CM of apoptotic T cells, followed by Nox2 mRNA destabilization. In in vivo models of polymicrobial sepsis such as cecal ligation and puncture, SYNCRIP was strongly downregulated, which was associated with a decreased Nox2 expression in peritoneal macrophages. Innovation: Downregulation of SYNCRIP in macrophages after contact to material of ACs destabilized Nox2 mRNA and impaired ROS formation, thereby contributing to an M2 phenotype shift of macrophages in sepsis. Conclusion: M2 polarization of macrophages in sepsis results in an attenuated SYNCRIP binding to the 3 ' UTR of Nox2 mRNA, destabilizing Nox2 mRNA abundance and expression. Consequently, ROS formation needed to fight against recurrent infections is impaired. In conclusion, SYNCRIP-regulated Nox2 mRNA degradation mediates the hypoinflammatory phase of sepsis. Antioxid. Redox Signal. 21, 2483-2497.