Lipopolysaccharide/adenosine triphosphate induces IL-1β and IL-18 secretion through the NLRP3 inflammasome in RAW264.7 murine macrophage cells

Abstract

Abstract. The NOD-like receptor family, pyrin domaincontaining 3 (NLRP3) inflammasome plays pivotal roles in inflammation and autoimmunity. The NLRP3 inflammasome is activated in response to various signals, including pathogenassociated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs). However, its role in inflammation remains unclear. In this study, we used lipopolysaccharide (LPS) and adenosine triphosphate (ATP) to simulate an inflammatory environment as the testing model. We found that the exposure of RAW264.7 cells to LPS/ATP triggered the activation of caspase-1 (P<0.01) and the cleavage of interleukin (IL)-1β (P<0.01), as well as the release of other cytokines, such as IL-18 (P<0.01) and IL-33 (P<0.01). Extracellular potassium chloride at a high concentration (150 mM) abrogated the secretion of IL-1β and IL-18 (P<0.01), but did not reduce the processing of IL-33 (P>0.05). In addition, the silencing of NLRP3 with small interfering RNA (siRNA) suppressed the generation of proinflammatory cytokines, such as IL-1β (P<0.01), IL-18 (P<0.01), but not IL-33 (P>0.05), along with the decreased mRNA and protein expression of NLRP3 and caspase-1 (P<0.05). However, extracellular potassium at a high concentration and NLRP3 siRNA did not affect the level of apoptosis-associated speck-like protein containing a caspase recruitment domain (CARD) (ASC; P>0.05). Our results suggest that the NLRP3/ASC/caspase-1 axis participates in the regulation of pro-imflammatory cytokine secretion in RAW264.7 cells, particularly the generation of IL-1β and IL-18.

Dexmedetomidine Alleviates Hyperoxia-Induced Acute Lung Injury via Inhibiting NLRP3 Inflammasome Activation

“…Previous studies showed that stimulation by LPS plus ATP could trigger the activation of NLRP3 inflammasome in RAW264.7 cells [38, 39]. Here, we observed that exposure to hyperoxia could result in NLRP3 inflammasome activation in RAW264.7 cells, which was consistent with the previous studies.…”

TET-2 up-regulation is associated with the anti-inflammatory action of Vicenin-2

“…For instance, exposure to bacterial lipopolysaccharide (LPS) induces an inflammatory phenotype in macrophages that is characterised by the expression of many proinflammatory cytokines including TNF-α and IL-1β [4]. The proinflammatory activities of macrophages is also associated with activation of NLR Family Pyrin Domain Containing 3 (NLRP3)-dependent inflammasome [5] and the nuclear transcription factor, NF-κB [6]. During the resolution of inflammation, macrophages produce mediators such as IL-10 and Interleukin-1 receptor antagonist (IL-Ra), that in turn, down-regulate inflammatory processes [7].…”

ATF3 inhibits the inflammation induced byMycoplasma pneumoniain vitro and in vivo

“…In accordance with these reports, our results also implicate the overexpression of ATF3 in the reduction of the mRNA and the secretion of TNF‐α, IL‐1β, and IL‐6 in RAW264.7, as well as mouse peritoneal macrophages. IL‐18 is a pro‐cytokine and induced by LPS in RAW264.7 murine macrophage cells . Moreover, the IL‐18 in BALF was increased after infected with Streptococcus pneumonia in mice .…”

“…IL-18 is a pro-cytokine and induced by LPS in RAW264.7 murine macrophage cells. 29 Moreover, the IL-18 in BALF was increased after infected with Streptococcus pneumonia in mice. 30 Prior study reported that was up-regulated in patients with MPP compared to no infected.…”