scholarly journals The role of annexin A1 in the modulation of the NLRP3 inflammasome

Immunology ◽  
2020 ◽  
Vol 160 (1) ◽  
pp. 78-89 ◽  
Author(s):  
Izabela Galvão ◽  
Renan V. H. de Carvalho ◽  
Juliana P. Vago ◽  
Alexandre L. N. Silva ◽  
Toniana G. Carvalho ◽  
...  
2020 ◽  
Author(s):  
Zhiquan Zhang ◽  
Qing Ma ◽  
Ravikanth Velagapudi ◽  
William E. Barclay ◽  
Ramona M. Rodriguiz ◽  
...  

AbstractNeuroinflammation is a growing hallmark of perioperative neurocognitive disorders (PNDs), including delirium and longer-lasting cognitive deficits. We have developed a clinically-relevant orthopedic mouse model to study the impact of a common surgical procedure on the vulnerable brain. The mechanism underlying PNDs remain unknown. Here we evaluated the impact of surgical trauma on the NLRP3 inflammasome signaling, including the expression of apoptosis-associated speck-like protein containing a CARD (ASC), caspase-1, and IL-1β in the hippocampus of C57BL6/J male mice, adult (3-months) and aged (>18-months). Surgery triggered ASC specks formation in CA1 hippocampal microglia, but without inducing significant morphological changes in NLRP3 and ASC knockout mice. Since no therapies are currently available to treat PNDs, we assessed the neuroprotective effects of a biomimetic peptide derived from the endogenous inflammation-ending molecule, Annexin-A1 (ANXA1). We tested the hypothesis that this peptide (ANXA1sp) inhibits NLRP3 inflammasome activation, thus preventing microglial activation and hippocampal-dependent memory deficits. Together these results uncover a previously underrecognized role of the NLRP3 inflammasome in triggering postoperative neuroinflammation and offer a new target for advancing treatment of PNDs through resolution of inflammation.


Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 121
Author(s):  
José Marcos Sanches ◽  
Rebeca D. Correia-Silva ◽  
Gustavo H. B. Duarte ◽  
Anna Maria A. P. Fernandes ◽  
Salvador Sánchez-Vinces ◽  
...  

This study evaluated the role of endogenous and exogenous annexin A1 (AnxA1) in the activation of the NLRP3 inflammasome in isolated peritoneal neutrophils. C57BL/6 wild-type (WT) and AnxA1 knockout mice (AnxA1-/-) received 0.3% carrageenan intraperitoneally and, after 3 h, the peritoneal exudate was collected. WT and AnxA1-/- neutrophils were then stimulated with lipopolysaccharide, followed by the NLRP3 agonists nigericin or ATP. To determine the exogenous effect of AnxA1, the neutrophils were pretreated with the AnxA1-derived peptide Ac2-26 followed by the NLRP3 agonists. Ac2-26 administration reduced NLRP3-derived IL-1β production by WT neutrophils after nigericin and ATP stimulation. However, IL-1β release was impaired in AnxA1-/- neutrophils stimulated by both agonists, and there was no further impairment in IL-1β release with Ac2-26 treatment before stimulation. Despite this, ATP- and nigericin-stimulated AnxA1-/- neutrophils had increased levels of cleaved caspase-1. The lipidomics of supernatants from nigericin-stimulated WT and AnxA1-/- neutrophils showed potential lipid biomarkers of cell stress and activation, including specific sphingolipids and glycerophospholipids. AnxA1 peptidomimetic treatment also increased the concentration of phosphatidylserines and oxidized phosphocholines, which are lipid biomarkers related to the inflammatory resolution pathway. Together, our results indicate that exogenous AnxA1 negatively regulates NLRP3-derived IL-1β production by neutrophils, while endogenous AnxA1 is required for the activation of the NLRP3 machinery.


Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 926 ◽  
Author(s):  
José Marcos Sanches ◽  
Laura Migliari Branco ◽  
Gustavo Henrique Bueno Duarte ◽  
Sonia Maria Oliani ◽  
Karina Ramalho Bortoluci ◽  
...  

Annexin A1 (AnxA1) is a potent anti-inflammatory protein that downregulates proinflammatory cytokine release. This study evaluated the role of AnxA1 in the regulation of NLRP3 inflammasome activation and lipid release by starch-elicited murine peritoneal macrophages. C57bl/6 wild-type (WT) and AnxA1-null (AnxA1-/-) mice received an intraperitoneal injection of 1.5% starch solution for macrophage recruitment. NLRP3 was activated by priming cells with lipopolysaccharide for 3 h, followed by nigericin (1 h) or ATP (30 min) incubation. As expected, nigericin and ATP administration decreased elicited peritoneal macrophage viability and induced IL-1β release, more pronounced in the AnxA1-/- cells than in the control peritoneal macrophages. In addition, nigericin-activated AnxA1-/- macrophages showed increased levels of NLRP3, while points of co-localization of the AnxA1 protein and NLRP3 inflammasome were detected in WT cells, as demonstrated by ultrastructural analysis. The lipidomic analysis showed a pronounced release of prostaglandins in nigericin-stimulated WT peritoneal macrophages, while ceramides were detected in AnxA1-/- cell supernatants. Different eicosanoid profiles were detected for both genotypes, and our results suggest that endogenous AnxA1 regulates the NLRP3-derived IL-1β and lipid mediator release in macrophages.


2017 ◽  
Author(s):  
Sehar Sajid ◽  
Derek Renshaw ◽  
Bernard Burke ◽  
Christopher Mee
Keyword(s):  

Author(s):  
Ishita Sharma ◽  
Tapan Behl ◽  
Simona Bungau ◽  
Monika Sachdeva ◽  
Arun Kumar ◽  
...  

Abstract:: Angina pectoris, associated with coronary artery disease, a cardiovascular disease where, pain is caused by adverse oxygen supply in myocardium, resulting in contractility and discomfort in chest. Inflammasomes, triggered by stimuli due to infection and cellular stress have identified to play a vital role in the progression of cardiovascular disorders and thus, causing various symptoms like angina pectoris. Nlrp3 inflammasome, a key contributor in the pathogenesis of angina pectoris, requires activation and primary signaling for the commencement of inflammation. Nlrp3 inflammasome elicit out an inflammatory response by emission of pro inflammatory cytokines by ROS (reactive oxygen species) production, mobilization of K+ efflux and Ca2+ and by activation of lysosome destabilization that eventually causes pyroptosis, a programmed cell death process. Thus, inflammasome are considered to be one of the factors involved in the progression of coronary artery diseases and have an intricate role in development of angina pectoris.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1231-1231
Author(s):  
Giulio Pasinetti

Abstract Objectives Chronic stress activates danger-associated molecular patterns (DAMPs), stimulating the NLRP3 inflammasome. NLRP3 activation triggers the release of pro-inflammatory cytokine IL-1β. The activity of the NLRP3 inflammasome propagates pro-inflammatory signaling cascades implicated in the onset of depression. Our previous studies show that polyphenolic compounds were found to ameliorate stress induced depression in mouse models. However, the relevant mechanism has not been identified. This study examined the effect of administering polyphenols on DAMP signaling in enriched mice microglia. Methods This study examined the effect of administering polyphenols on DAMP signaling in mice microglia. To recapitulate stress-induced depression, mice underwent chronic unpredictable stress (CUS). Microglia were isolated at various time points throughout the CUS protocol. We also assessed long-term persistent changes after CUS and susceptibility to subthreshold unpredictable stress (US) re-exposure. Results Interestingly, the development of US – induced depression and anxiety depended upon a previous exposure to CUS. We found that CUS caused robust upregulation of IL-1β mRNA in enriched microglia, an effect that persists for up to 4 weeks following CUS exposure. Following the subthreshold US re-exposure, we observed the upregulation of pro- IL-1β as well as pro-receptor for advanced glycation end products (RAGE). Toll-like receptor 4 (TLR-4) was not. We also observed an increase in RAGE mRNA expression when mice were exposed to US prior to the start of the CUS paradigm. Importantly, a primary exposure to US, was sufficient to increase RAGE mRNA expression. We found that polyphenol administration significantly improved CUS-induced depressive-like phenotypes and also reversed neuroinflammation in mice. Treatment with dietary flavonoids prevented upregulation of IL-1β, RAGE mRNA, which reflects the ability of polyphenols that may have begun following the primary exposure to US. Conclusions Taken all together, the results provide evidence of the role of dietary polyphenols in preventing persistent microglial activation, which has been shown to result in reduced long term vulnerability to depressive-like behaviors following expose to chronic stress. Funding Sources This study was supported by a P50 CARBON Center grant from the NCCIH/ODS.


Author(s):  
Fillipe M. de Araújo ◽  
Lorena Cuenca-Bermejo ◽  
Emiliano Fernández-Villalba ◽  
Silvia L. Costa ◽  
Victor Diogenes A. Silva ◽  
...  

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
W Zuo ◽  
R Tian ◽  
Q Chen ◽  
L Wang ◽  
Q Gu ◽  
...  

Abstract Background Myocardial ischemia-reperfusion injury (MIRI) is one of the leading causes of human death. Nod-like receptor protein-3 (NLRP3) inflammasome signaling pathway involved in the pathogenesis of MIRI. However, the upstream regulating mechanisms of NLRP3 at molecular level remains unknown. Purpose This study investigated the role of microRNA330-5p (miR-330-5p) in NLRP3 inflammasome-mediated MIRI and the associated mechanism. Methods Mice underwent 45 min occlusion of the left anterior descending coronary artery followed by different times of reperfusion. Myocardial miR-330-5p expression was examined by quantitative polymerase chain reaction (PCR), and miR-330-5p antagomir and agomir were used to regulate miR-330-5p expression. To evaluate the role of miR-330-5p in MIRI, Evans Blue (EB)/2, 3, 5-triphenyltetrazolium chloride (TTC) staining, echocardiography, and immunoblotting were used to assess infarct volume, cardiac function, and NLRP3 inflammasome activation, respectively. Further, in vitro myocardial ischemia-reperfusion model was established in cardiomyocytes (H9C2 cell line). A luciferase binding assay was used to examine whether miR-330-5p directly bound to T-cell immunoglobulin domain and mucin domain-containing molecule-3 (TIM3). Finally, the role of miR-330-5p/TIM3 axis in regulating apoptosis and NLRP3 inflammasome formation were evaluated using flow cytometry assay and immunofluorescence staining. Results Compared to the model group, inhibiting miR-330-5p significantly aggravated MIRI resulting in increased infarct volume (58.09±6.39% vs. 37.82±8.86%, P<0.01) and more severe cardiac dysfunction (left ventricular ejection fraction [LVEF] 12.77%±6.07% vs. 27.44%±4.47%, P<0.01; left ventricular end-diastolic volume [LVEDV] 147.18±25.82 vs. 101.31±33.20, P<0.05; left ventricular end-systolic volume [LVESV] 129.11±30.17 vs. 74.29±28.54, P<0.05). Moreover, inhibiting miR-330-5p significantly increased the levels of NLRP3 inflammasome related proteins including caspase-1 (0.80±0.083 vs. 0.60±0.062, P<0.05), interleukin (IL)-1β (0.87±0.053 vs. 0.79±0.083, P<0.05), IL-18 (0.52±0.063 vs. 0.49±0.098, P<0.05) and tissue necrosis factor (TNF)-α (1.47±0.17 vs. 1.03±0.11, P<0.05). Furthermore, TIM3 was confirmed as a potential target of miR-330-5p. As predicted, suppression of TIM3 by small interfering RNA (siRNA) ameliorated the anti-miR-330-5p-mediated apoptosis of cardiomyocytes and activation of NLRP3 inflammasome signaling pathway (Figure 1). Conclusion Overall, our study indicated that miR-330-5p/TIM3 axis involved in the regulating mechanism of NLRP3 inflammasome-mediated myocardial ischemia-reperfusion injury. Figure 1 Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): National Natural Science Foundation of China Grants


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