Anti-Inflammatory Activity of PYNOD and Its Mechanism in Humans and Mice
Anti-Inflammatory Activity of PYNOD and Its Mechanism in Humans and Mice
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DOI：
10.4049/jimmunol.0900779
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发表时间：
2010-05-15
影响因子：
4.4
通讯作者：
Suda, Takashi
中科院分区：
文献类型：
--
作者：
Imamura, Ryu;Wang, Yetao;Suda, Takashi
核苷酸结合和寡聚化结构域(NOD)和富含亮氨酸重复序列的蛋白(NLR)家族中的许多成员在病原体识别和炎症中发挥着重要作用。然而，我们先前报道，人PYNOD/NLRP10是一种由PYNOD结构域和NOD结构域组成的NLR样蛋白，在HEK293细胞重建实验中抑制由caspase-1和含有caspase募集域(ASC)的凋亡相关SPECK样蛋白介导的炎症信号。本研究对PYNOD体外抗炎作用的分子机制及其在小鼠体内的表达和作用进行了研究。人PYNOD抑制半胱氨酸天冬氨酸氨基转移酶-1和半胱氨酸天冬氨酸氨基转移酶-L介导的IL-1β的自动处理，并抑制天冬氨酸天冬氨酸细胞的聚集，天冬氨酸天冬氨酸细胞是天冬氨酸天冬氨酸细胞活化的标志。有趣的是，人PYNOD的NOD足以抑制caspase-1介导的IL-1β的分泌，而其吡咯结构域足以抑制ASC介导的核因子-kappaB的激活和凋亡，并降低ASC促进caspase-1介导的IL-1β产生的能力。在皮肤、舌头、心脏、结肠、腹膜巨噬细胞以及几种造血系和肌系细胞系中检测到小鼠PYNOD蛋白。在LPS+R837刺激的巨噬细胞中，小鼠PYNOD与ASC聚集体共存；然而，与人PYNOD不同，小鼠PYNOD不能抑制ASC聚集。PYNOD转基因小鼠的巨噬细胞和中性粒细胞在微生物感染时表现出IL-1β的处理和分泌减少，尽管小鼠PYNOD未能抑制caspase-1的处理，caspase-4抑制剂z-LEED-氟甲基酮抑制了caspase-1的处理。这些结果表明，小鼠PYNOD与ASC共定位，并抑制caspase-1介导的IL-1β处理，而不抑制caspase-4(小鼠caspase-11)介导的caspase-1处理。此外，PYNOD转基因小鼠对致死性内毒素休克具有抵抗力。因此，PYNOD是第一个在体内具有抗炎功能的NLR例子。免疫学杂志，2010,184：5874-5884。
Many members of the nucleotide-binding and oligomerization domain (NOD)- and leucine-rich-repeat-containing protein (NLR) family play important roles in pathogen recognition and inflammation. However, we previously reported that human PYNOD/NLRP10, an NLR-like protein consisting of a pyrin domain and a NOD, inhibits inflammatory signal mediated by caspase-1 and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) in reconstitution experiments using HEK293 cells. In this study, we investigated the molecular mechanism of PYNOD's anti-inflammatory activity in vitro and its expression and function in mice. Human PYNOD inhibited the autoprocessing of caspase-1 and caspase-l-mediated IL-1 beta processing and suppressed the aggregation of ASC, a hallmark of ASC activation. Interestingly, the NOD of human PYNOD was sufficient to inhibit caspase-1-mediated IL-1 beta secretion, whereas its pyrin domain was sufficient to inhibit ASC-mediated NF-kappa B activation and apoptosis and to reduce ASC's ability to promote caspase-1-mediated IL-1 beta production. Mouse PYNOD protein was detected in the skin, tongue, heart, colon, peritoneal macrophages, and several cell lines of hematopoietic and myocytic lineages. Mouse PYNOD colocalized with ASC aggregates in LPS + R837-stimulated macrophages; however, unlike human PYNOD, mouse PYNOD failed to inhibit ASC aggregation. Macrophages and neutrophils from PYNOD-transgenic mice exhibited reduced IL-1 beta processing and secretion upon microbial infection, although mouse PYNOD failed to inhibit caspase-1 processing, which was inhibited by caspase-4 inhibitor z-LEED-fluoromethylketone. These results suggest that mouse PYNOD colocalizes with ASC and inhibits caspase-1-mediated IL-1 beta processing without inhibiting caspase-4 (mouse caspase-11)-mediated caspase-1 processing. Furthermore, PYNOD-transgenic mice were resistant to lethal endotoxic shock. Thus, PYNOD is the first example of an NLR that possesses an anti-inflammatory function in vivo. The Journal of Immunology, 2010,184: 5874-5884.