Characterization of porcine NLRP3 inflammasome activation and its upstream mechanism

Abstract

Inflammasomes, which are intracellular sensors of endogenous or exogenous danger signals, activate caspase-1, resulting in interleukin (IL)-1β maturation. Although most studies on inflammasomes have been performed in human and/or mouse-derived macrophages, porcine inflammasome activation has not been elucidated even though pigs are considered one of the best animal models for translational and preclinical investigations. In this study, we optimized detection of porcine IL-1β secretion, which is the most well established indicator of inflammasome activation, and compared inflammasome activation between miniature and domestic pigs as well as between porcine and murine macrophages. In our results, anti-sera against murine IL-1β had higher affinity to porcine IL-1β than anti-sera against human IL-1β, even though the amino acid sequence of porcine IL-1β was more similar to that of human IL-1β. In addition, there was no significant difference in inflammasome activation between miniature and domestic pigs. Furthermore, well established inflammasome triggers (ATP, nigericin, and crystals) in humans and mice had similar effects on porcine NLRP3 inflammasome activation. We further elucidated the upstream signaling pathway of porcine inflammasome activation using pharmacological inhibitors. Similar to the mechanisms of inflammasome activation in humans and mice, potassium efflux and reactive oxygen species generation were confirmed as key pathways in porcine inflammasome activation. Thus, inflammasome activation in pigs is not different from that in humans or mice.

Phosphatidylinositol 3-kinases pathway mediates lung caspase-1 activation and high mobility group box 1 production in a toluene-diisocyanate induced murine asthma model

“…As far as we know, plenty of evidence suggested that PI3K signaling plays a pivotal role downstream of oxidative stress in airway inflammation (Marwick et al, 2009) and in pulmonary epithelial cells (Papaiahgari et al, 2006). Oxidative stress was an vitally important mechanism involved in TDI induced asthma (Shin et al, 2013) as well as the most well-established upstream of caspase-1 (Kim et al, 2014). Therefore, it is possible that ROS/PI3K signal pathway mediates TDI induced caspase-1 activation, which deserves our future investigation.…”

The anti-inflammatory effects of baicalin through suppression of NLRP3 inflammasome pathway in LPS-challenged piglet mononuclear phagocytes

“…In pigs, it is not different from that in humans or mice. 27 The NLRP3 inflammasome is now recognized as a critical molecular mechanism for many degenerative diseases. 27 Several models have been developed to describe how NLRP3 inflammasomes are activated, including K + efflux, lysosome function, ER stress, intracellular calcium, ubiquitination, microRNAs and, in particular, ROS.…”

Lentinan from shiitake selectively attenuates AIM2 and non-canonical inflammasome activation while inducing pro-inflammatory cytokine production

“…For inflammasome activation, BMDMs (1.0 × 10 6 cells per well) in RPMI 1640 containing 10% FBS and antibiotics were seeded in 12-well tissue culture plates (SPL Life Science Co.) and primed with lipopolysaccharide (LPS, 1 μg/mL; #L4130, Sigma-Aldrich Co., St. Louis, MO, USA) 43, 44 . After 3 h, LPS-primed BMDMs were given fresh media (RPMI 1640, 350 μL in 12-well plates) without FBS or antibiotics in the presence of adenosine triphosphate (2 mM, ATP; #tlrl-atp, InvivoGen, San Diego, CA, USA) for 1 h, nigericin (40 μM, NG; #4312 Tocris Bioscience, Bristol, UK) for 1 h, flagellin (0.5 μg/mL; #tlrl-stfla, InvivoGen) with Lipofectamine 2000 (10 μL/mL, Invitrogen, Grand Island, NY, USA) for 1 h, double-stranded DNA (1 μg/mL, dsDNA) with jetPRIME TM (2 μL/mL, Polyplus-transfection Inc., Illkirch, France) for 1 h, monosodium urate crystals (800 μg/mL, MSU, Sigma-Aldrich Co.) for 6 h, LPS (14 μg/mL) with Lipofectamine 2000 (10 μL/mL) for 6 h, or Escherichia coli ( E .…”