ARIH2 Ubiquitinates NLRP3 and Negatively Regulates NLRP3 Inflammasome Activation in Macrophages
ARIH2 Ubiquitinates NLRP3 and Negatively Regulates NLRP3 Inflammasome Activation in Macrophages
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ARIH2泛素化NLRP3并负调控巨噬细胞NLRP3炎性体激活
DOI：
10.4049/jimmunol.1700184
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发表时间：
2017-11-15
影响因子：
4.4
通讯作者：
Takahashi, Masafumi
中科院分区：
文献类型：
--
作者：
Kawashima, Akira;Karasawa, Tadayoshi;Takahashi, Masafumi
核苷酸结合的寡聚结构域样受体家族3(NLRP3)炎症体是一个诱导caspase-1激活和随后的IL-1b成熟的分子平台，与炎症性疾病有关，但对NLRP3炎症体激活的负调控知之甚少。在本文中，我们发现了一个E3连接酶Ariadne Homolog 2(Arih2)，它是巨噬细胞中NLRP3炎症体活性的翻译后负调控因子。在NLRP3炎症体复合体中，Arih2通过其Nacht结构域(aa220-575)与NLRP3相互作用。特别是，我们发现，当使用Arih2和泛素的突变体时，Arih2真正有趣的新基因2结构域是通过K48和K63连接的NLRP3泛素化所必需的。利用CRISPR/Cas9基因组编辑技术删除内源性Arih2抑制了NLRP3泛素化，促进了NLRP3炎症小体的激活，导致了含有caspase招募结构域的凋亡相关斑点样蛋白的寡聚、前IL-1b加工和IL-1b的产生。相反，Arih2过表达促进了NLRP3泛素化，抑制了NLRP3炎症体的激活。我们的发现揭示了Arih2对NLRP3炎症体的泛素化依赖的新的负调控机制，并突出了Arih2作为炎症性疾病的潜在治疗靶点的可能性。
The nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome is a molecular platform that induces caspase-1 activation and subsequent IL-1b maturation, and is implicated in inflammatory diseases; however, little is known about the negative regulation of NLRP3 inflammasome activation. In this article, we identified an E3 ligase, Ariadne homolog 2 (ARIH2), as a posttranslational negative regulator of NLRP3 inflammasome activity in macrophages. ARIH2 interacted with NLRP3 via its NACHT domain (aa 220-575) in the NLRP3 inflammasome complex. In particular, we found that while using mutants of ARIH2 and ubiquitin, the really interesting new gene 2 domain of ARIH2 was required for NLRP3 ubiquitination linked through K48 and K63. Deletion of endogenous ARIH2 using CRISPR/Cas9 genome editing inhibited NLRP3 ubiquitination and promoted NLRP3 inflammasome activation, resulting in apoptosis-associated speck-like protein containing a caspase recruitment domain oligomerization, pro-IL-1b processing, and IL-1b production. Conversely, ARIH2 overexpression promoted NLRP3 ubiquitination and inhibited NLRP3 inflammasome activation. Our findings reveal a novel mechanism of ubiquitination-dependent negative regulation of the NLRP3 inflammasome by ARIH2 and highlight ARIH2 as a potential therapeutic target for inflammatory diseases.