NLRP3 inflammasome expression is driven by NF-κB in cultured hepatocytes
NLRP3 inflammasome expression is driven by NF-κB in cultured hepatocytes
复制标题
DOI：
10.1016/j.bbrc.2015.02.029
复制
发表时间：
2015-03-13
影响因子：
3.1
通讯作者：
Weiskirchen, Ralf
中科院分区：
文献类型：
--
作者：
Boaru, Sorina Georgiana;Borkham-Kamphorst, Erawan;Weiskirchen, Ralf
炎性小体是负责激活炎症反应的细胞质多蛋白复合物。原则上，存在四个单独的炎性体分支（NLRP 1、NLRP 3、NLRC 4/NALP 4和AIM 2），其介导半胱天冬酶-1和IL-1 β的裂解和活化，这进而导致引发局部和全身炎性反应的细胞反应的复杂网络。我们最近发现，NLRP 3的表达在原代培养的肝细胞中几乎不存在，并且在体外用脂多糖刺激肝细胞导致NLRP 3表达的强烈激活。我们在这里证明，这种激活可以通过NF-κ B激活抑制剂QNZ或通过用组成型表达NF-κ B超阻遏物的腺病毒表达载体感染来阻断。我们发现QNZ阻断TNF-α、IL-1 β和NLRP 3的NF-κ B依赖性表达。同样，NF-κ B的超阻遏物阻止NLRP 3的表达，并显著降低肝细胞中炎性标志物基因的表达。在原代鼠肝癌细胞中，NEMO和Caspase-8的伴随消耗导致脂多糖攻击后NLRP 3表达的显著抑制。此外，我们证明，位于最上游的转录起始位点的人NLRP 3基因，窝藏一个假定的八聚体NF-κ B结合位点附近的1.3 kbp的片段，使LPS的敏感性在报告基因测定。我们得出结论，NF-κ B信号传导是原代肝细胞中NLRP 3炎性体适当激活的必要先决条件。(C)2015 Elsevier Inc. All rights reserved.
The inflammasomes are cytoplasmic multiprotein complexes that are responsible for activation of inflammatory reactions. In principle, there are four individual inflammasome branches (NLRP1, NLRP3, NLRC4/NALP4, and AIM2) that mediate the cleavage and activation of Caspase-1 and IL-1 beta that in turn lead to a complex network of cellular reactions initiating local and systemic inflammatory reactions. We have recently shown that NLRP3 expression is virtually absent in primary cultured hepatocytes and that in vitro the stimulation of hepatocytes with lipopolysaccharides results in strong activation of NLRP3 expression. We here demonstrate that this activation can be blocked by the NF-kappa B activation inhibitor QNZ or by infection with an adenoviral expression vector constitutively expressing a superrepressor of NF-kappa B. We show that QNZ blocks NF-kappa B-dependent expression of TNF-alpha, IL-1 beta and NLRP3. Likewise, the superrepressor of NF-kappa B prevents expression of NLRP3 and significantly reduces expression of inflammatory marker genes in liver cells. In a primary murine hepatoma cells, the concomitant depletion of NEMO and Caspase-8 resulted in a significant suppression of NLRP3 expression after Lipopolysaccharide challenge. Moreover, we demonstrate that a 1.3-kbp fragment located in close proximity of the most upstream transcriptional start site of the human NLRP3 gene that harbours one putative octamer NF-kappa B binding site renders LPS sensitivity in reporter gene assay. We conclude that NF-kappa B signalling is a necessary prerequisite for proper activation of the NLRP3 inflammasome in primary hepatocytes. (C) 2015 Elsevier Inc. All rights reserved.