Role of Stat3 in NLRP3/caspase‐1‐mediated hippocampal neuronal pyroptosis in epileptic mice

Synapse ◽  
2021 ◽  
Author(s):  
Qian Jiang ◽  
Guo Tang ◽  
Xue‐Min Zhong ◽  
Dan‐Rui Ding ◽  
Hui Wang ◽  
...  
Keyword(s):  
Caspase 1

scholarly journals GSDMD contributes to host defence against Staphylococcus aureus skin infection by suppressing the Cxcl1–Cxcr2 axis

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Zhen-Zhen Liu ◽  
Yong-Jun Yang ◽  
Feng-Hua Zhou ◽  
Ke Ma ◽  
Xiao-Qi Lin ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Skin Infection ◽  
Bacterial Colonization ◽  
Critical Role ◽  
Host Defence ◽  
Skin Damage ◽  
Microbial Infection ◽  
Caspase 1 ◽  
Deficient Mice

AbstractGasdermin D (GSDMD), a member of the gasdermin protein family, is a caspase substrate, and its cleavage is required for pyroptosis and IL-1β secretion. To date, the role and regulatory mechanism of GSDMD during cutaneous microbial infection remain unclear. Here, we showed that GSDMD protected against Staphylococcus aureus skin infection by suppressing Cxcl1–Cxcr2 signalling. GSDMD deficiency resulted in larger abscesses, more bacterial colonization, exacerbated skin damage, and increased inflammatory cell infiltration. Although GSDMD deficiency resulted in defective IL-1β production, the critical role of IL-1β was counteracted by the fact that Caspase-1/11 deficiency also resulted in less IL-1β production but did not aggravate disease severity during S. aureus skin infection. Interestingly, GSDMD-deficient mice had increased Cxcl1 secretion accompanied by increased recruitment of neutrophils, whereas Caspase-1/11-deficient mice presented similar levels of Cxcl1 and neutrophils as wild-type mice. Moreover, the absence of GSDMD promoted Cxcl1 secretion in bone marrow-derived macrophages induced by live, dead, or different strains of S. aureus. Corresponding to higher transcription and secretion of Cxcl1, enhanced NF-κB activation was shown in vitro and in vivo in the absence of GSDMD. Importantly, inhibiting the Cxcl1–Cxcr2 axis with a Cxcr2 inhibitor or anti-Cxcl1 blocking antibody rescued host defence defects in the GSDMD-deficient mice. Hence, these results revealed an important role of GSDMD in suppressing the Cxcl1–Cxcr2 axis to facilitate pathogen control and prevent tissue damage during cutaneous S. aureus infection.

scholarly journals ATP Induces IL-1βSecretion inNeisseria gonorrhoeae-Infected Human Macrophages by a Mechanism Not Related to the NLRP3/ASC/Caspase-1 Axis

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Killen García ◽  
Gisselle Escobar ◽  
Pablo Mendoza ◽  
Caroll Beltran ◽  
Claudio Perez ◽  
...  
Keyword(s):  
Immune Responses ◽  
Immune Evasion ◽  
Transcriptional Activation ◽  
Pore Formation ◽  
Human Monocyte ◽  
Positive Staining ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Caspase 1

Neisseria gonorrhoeae(Ngo) has developed multiple immune evasion mechanisms involving the innate and adaptive immune responses. Recent findings have reported that Ngo reduces the IL-1βsecretion of infected human monocyte-derived macrophages (MDM). Here, we investigate the role of adenosine triphosphate (ATP) in production and release of IL-1βin Ngo-infected MDM. We found that the exposure of Ngo-infected MDM to ATP increases IL-1βlevels about ten times compared with unexposed Ngo-infected MDM (P<0.01). However, we did not observe any changes in inflammasome transcriptional activation of speck-like protein containing a caspase recruitment domain (CARD) (ASC,P>0.05) and caspase-1 (CASP1,P>0.05). In addition, ATP was not able to modify caspase-1 activity in Ngo-infected MDM but was able to increase pyroptosis (P>0.01). Notably ATP treatment defined an increase of positive staining for IL-1βwith a distinctive intracellular pattern of distribution. Collectively, these data demonstrate that ATP induces IL-1βsecretion by a mechanism not related to the NLRP3/ASC/caspase-1 axis and likely is acting at the level of vesicle trafficking or pore formation.

scholarly journals miR-29a-5p Alleviates Traumatic Brain Injury (TBI)-Induced Permeability Disruption Via Regulating NLRP3 Pathway

2021 ◽  
Author(s):  
Aijun Zhang ◽  
Youming Lu ◽  
Lei Yuan ◽  
Pengqi Zhang ◽  
Dongdong Zou ◽  
...  
Keyword(s):  
Gene Expression ◽  
Traumatic Brain Injury ◽  
Endothelial Cell ◽  
Brain Injury ◽  
Inflammasome Activation ◽  
Caspase 1 ◽  
Promising Strategy ◽  
Pathway Activation ◽  
Nlrp3 Expression

Abstract Blood-brain barrier (BBB) dysfunction is presented during traumatic brain injury (TBI) and is dependent upon the activation of the NLRP3/Caspase-1 inflammasome pathway. MicroRNA (miRNA) was proved to inhibit signaling pathway activation by targeting gene expression and we predicated in the database that miR-29a targets to NLRP3. Herein, this study aims to define the regulating role of miR-29a in NLRP3 expression and NLRP3/Caspase-1 inflammasome activation in TBI-induced BBB dysfunction. Our results indicated that miR-29a-5p alleviates TBI-induced the increased permeability of endothelial cell and BBB via suppressing NLRP3 expression and NLRP3/Caspase-1 inflammasome activation, providing a promising strategy for relieving TBI via inhibiting NLRP3/Caspase-1 inflammasome activation.

scholarly journals USP7 Inhibition Alleviates H2O2-Induced Injury in Chondrocytes via Inhibiting NOX4/NLRP3 Pathway

2021 ◽  
Vol 11 ◽  
Author(s):  
Gang Liu ◽  
Qingbai Liu ◽  
Bin Yan ◽  
Ziqiang Zhu ◽  
Yaozeng Xu
Keyword(s):  
Treatment Options ◽  
Current Treatment ◽  
Pathological Process ◽  
Joint Disease ◽  
Matrix Remodeling ◽  
Ros Production ◽  
Caspase 1 ◽  
Enhanced Production

Osteoarthritis (OA), the most common form of arthritis, is a very common joint disease that often affects middle-aged to elderly people. However, current treatment options for OA are predominantly palliative. Thus, understanding its pathological process and exploring its potential therapeutic approaches are of great importance. Rat chondrocytes were isolated and exposed to hydrogen peroxide (H2O2) to mimic OA. The effects of H2O2 on ubiquitin-specific protease 7 (USP7) expression, reactive oxygen species (ROS) levels, proliferation, inflammatory cytokine release, and pyroptosis were measured. USP7 was knocked down (KD) or overexpressed to investigate the role of USP7 in OA. Co-immunoprecipitation (Co-IP) was used to study the interaction between USP7 and NAD(P)H oxidases (NOX)4 as well as NOX4 ubiquitination. NOX4 inhibitor was applied to study the involvement of NOX4 in USP7-mediated OA development. USP7 inhibitor was given to OA animals to further investigate the role of USP7 in OA in vivo. Moreover, H2O2 treatment significantly increased USP7 expression, enhanced ROS levels, and inhibited proliferation in rat chondrocytes. The overexpression of USP7 enhanced pyroptosis, ROS production, interleukin (IL)-1β and IL-18 levels, and the expression level of NLRP3, GSDMD-N, active caspase-1, pro-caspase-1, matrix metalloproteinases (MMP) 1, and MMP13, which was abolished by ROS inhibition. The USP7 KD protected rat chondrocytes against H2O2-induced injury. Co-IP results showed that USP7 interacted with NOX4, and USP7 KD enhanced NOX4 ubiquitinylation. The inhibition of NOX4 blocked the pro-OA effect of USP7. Moreover, the USP7 inhibitor given to OA animals suppressed OA in vivo. USP7 inhibited NOX4 ubiquitination for degradation which leads to elevated ROS production. ROS subsequently activates NLPR3 inflammasome, leading to enhanced production of IL-1β and IL-18, GSDMD-N-dependent pyroptosis, and extracellular matrix remodeling. Thus, UPS7 contributes to the progression of OA via NOX4/ROS/NLPR3 axis.

scholarly journals Role of Short-wavelength Blue Light in the Formation of Cataract and Expression of Caspase-1, -11 and Gasdermin D in rat Lens Epithelium Cells: Insight into the Novel Pathogenesis of Cataract.

2019 ◽  
Author(s):  
Yamin Wang ◽  
Min Zhang ◽  
Ying Sun ◽  
Xiaohui Wang ◽  
Zhaowei Song ◽  
...  
Keyword(s):  
Blue Light ◽  
Short Wavelength ◽  
Light Exposure ◽  
The Novel ◽  
Blue Led ◽  
Caspase 1 ◽  
Epithelium Cells ◽  
Experimental Group ◽  
Insight Into

Abstract Background Cataracts have been verified to be associated with a number of risk factors. The sun and artificial light sources, including light-emitting diode (LED) and fluorescent light tubes, are the primary sources of short-wavelength blue light. With the increasing popularity of blue-rich LED-backlit display devices, our eyes are now exposed to more short-wavelength blue light than they were in the past. The goal of this study was to evaluate the role of short-wavelength blue light in the formation of cataract. Additionally, the pathogenesis of cataracts after short-wavelength light exposure was investigated.Methods SD rats were randomly divided into 2 main groups: a control group (10 rats each for the 4-, 8-, and 12-week groups) and an experimental group (10 rats each for the 4-, 8-, and 12-week groups). The rats in the experimental group were exposed to a short-wavelength blue LED lamp for 12 hours per day. After exposure to the blue LED lamp, the rats were maintained in total darkness for 12 hours, after which a 12-hour light/dark cycle was resumed. The intensity of the lamp was 3000 lux. At the end of the short-wavelength blue LED lamp exposure (for 4, 8, and 12 weeks), the expression levels of caspase-1, caspase-11 and gasdermin D (GSDMD) in rat epithelium cells (LECs) were examined in rat epithelial cells (LECs) using qRT-PCR and Western blotting analyses. Results After 6 weeks, cataracts had developed in the experimental rats (4/20 eyes). The clarity of the lens then gradually worsened with the duration of exposure. Twelve weeks later, all of the rat eyes had developed cataracts. Then the expression levels of caspase-1, caspase-11 and GSDMD at 4, 8, and 12 weeks were significantly higher in samples from rats exposed to a short-wavelength blue LED lamp than samples from control rat (p˂0.05). Conclusion The data indicate that pyroptosis play a key role of in cataracts induced by short-wavelength blue light exposure, highlighting caspase-1, caspase-11 and GSDMD as possible therapeutic targets for cataract treatment. This study might provide new insight into the novel pathogenesis of cataracts.

scholarly journals Macrophage Uptake of Necrotic Cell DNA Activates the AIM2 Inflammasome to Regulate a Proinflammatory Phenotype in CKD

2018 ◽  
Vol 29 (4) ◽  
pp. 1165-1181 ◽  
Author(s):  
Takanori Komada ◽  
Hyunjae Chung ◽  
Arthur Lau ◽  
Jaye M. Platnich ◽  
Paul L. Beck ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Inflammasome Activation ◽  
Dna Uptake ◽  
Chronic Injury ◽  
Caspase 1 ◽  
Double Stranded Dna ◽  
Molecular Pattern ◽  
Macrophage Uptake

Nonmicrobial inflammation contributes to CKD progression and fibrosis. Absent in melanoma 2 (AIM2) is an inflammasome-forming receptor for double-stranded DNA. AIM2 is expressed in the kidney and activated mainly by macrophages. We investigated the potential pathogenic role of the AIM2 inflammasome in kidney disease. In kidneys from patients with diabetic or nondiabetic CKD, immunofluorescence showed AIM2 expression in glomeruli, tubules, and infiltrating leukocytes. In a mouse model of unilateral ureteral obstruction (UUO), Aim2 deficiency attenuated the renal injury, fibrosis, and inflammation observed in wild-type (WT) littermates. In bone marrow chimera studies, UUO induced substantially more tubular injury and IL-1β cleavage in Aim2−/− or WT mice that received WT bone marrow than in WT mice that received Aim2−/− bone marrow. Intravital microscopy of the kidney in LysM(gfp/gfp) mice 5–6 days after UUO demonstrated the significant recruitment of GFP+ proinflammatory macrophages that crawled along injured tubules, engulfed DNA from necrotic cells, and expressed active caspase-1. DNA uptake occurred in large vacuolar structures within recruited macrophages but not resident CX3CR1+ renal phagocytes. In vitro, macrophages that engulfed necrotic debris showed AIM2-dependent activation of caspase-1 and IL-1β, as well as the formation of AIM2+ ASC specks. ASC specks are a hallmark of inflammasome activation. Cotreatment with DNaseI attenuated the increase in IL-1β levels, confirming that DNA was the principal damage-associated molecular pattern in this process. Therefore, the activation of the AIM2 inflammasome by DNA from necrotic cells drives a proinflammatory phenotype that contributes to chronic injury in the kidney.

scholarly journals The signaling adaptor BCAP inhibits NLRP3 and NLRC4 inflammasome activation in macrophages through interactions with Flightless-1

2019 ◽  
Vol 12 (581) ◽  
pp. eaau0615 ◽  
Author(s):  
Samuel J. Carpentier ◽  
Minjian Ni ◽  
Jeffrey M. Duggan ◽  
Richard G. James ◽  
Brad T. Cookson ◽  
...  
Keyword(s):  
B Cell ◽  
Yersinia Pseudotuberculosis ◽  
Cell Receptor ◽  
Pi3k Pathway ◽  
Inflammasome Activation ◽  
Interacting Protein ◽  
Caspase 1 ◽  
B Cell Receptor Signaling ◽  
Phosphoinositide 3 Kinase

B cell adaptor for phosphoinositide 3-kinase (PI3K) (BCAP) is a signaling adaptor that activates the PI3K pathway downstream of B cell receptor signaling in B cells and Toll-like receptor (TLR) signaling in macrophages. BCAP binds to the regulatory p85 subunit of class I PI3K and is a large, multidomain protein. We used proteomic analysis to identify other BCAP-interacting proteins in macrophages and found that BCAP specifically associated with the caspase-1 pseudosubstrate inhibitor Flightless-1 and its binding partner leucine-rich repeat flightless-interacting protein 2. Because these proteins inhibit the NLRP3 inflammasome, we investigated the role of BCAP in inflammasome function. Independent of its effects on TLR priming, BCAP inhibited NLRP3- and NLRC4-induced caspase-1 activation, cell death, and IL-1β release from macrophages. Accordingly, caspase-1–dependent clearance of a Yersinia pseudotuberculosis mutant was enhanced in BCAP-deficient mice. Mechanistically, BCAP delayed the recruitment and activation of pro–caspase-1 within the NLRP3/ASC preinflammasome through its association with Flightless-1. Thus, BCAP is a multifunctional signaling adaptor that inhibits key pathogen-sensing pathways in macrophages.

scholarly journals Exendin-4 Protects against Hyperglycemia-Induced Cardiomyocyte Pyroptosis via the AMPK-TXNIP Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Hong Wei ◽  
Rui Bu ◽  
Qinghui Yang ◽  
Jing Jia ◽  
Tao Li ◽  
...  
Keyword(s):  
Diabetic Cardiomyopathy ◽  
High Fat Diet ◽  
Rna Silencing ◽  
Diabetic Heart ◽  
Cardiac Inflammation ◽  
Caspase 1 ◽  
Signaling Mechanisms ◽  
Patients With Diabetes ◽  
Cardiac Condition

Diabetic cardiomyopathy is a common cardiac condition in patients with diabetes mellitus, which results in cardiac hypertrophy and subsequent heart failure. Chronic inflammation in the diabetic heart results in loss of cardiomyocytes and subsequentially cardiac dysfunction. Accumulated evidence implicated pyroptosis as a vital contributor to the hyperglycemia-induced cardiac inflammatory response. Exendin-4, a GLP analog, promotes survival of cardiomyocytes in cardiovascular diseases, including diabetic cardiomyopathy. However, the role of Exendin-4 in cardiac pyroptosis remains to be elucidated. Our study revealed that Exendin-4 treatment protected against heart remolding and dysfunction and attenuated cardiac inflammation in high-fat diet-fed rats. The activity of caspase-1 and production of pyroptotic cytokines were significantly inhibited by Exendin-4 treatment in the diabetic heart and in high glucose-treated cardiomyocytes as well. In an effort to understand the signaling mechanisms underlying the antipyroptotic property of Exendin-4, we found that blockade of AMPK, an oxidative stress sensor, activity diminished the antipyroptotic property of Exendin-4. Phosphorylation of AMPK resulted in degeneration of TXNIP that promoted the activation of the NLRP3 inflammasome. Exendin-4 treatment decreased the protein level of TXNIP. Moreover, RNA silencing of TXNIP mimicked the antipyroptotic actions of Exendin-4. These findings promoted us to propose a new signaling pathway mediating cardioprotective effect of Exendin-4 under hyperglycemic conditions: Exendin-4 → ROS↓ → pAMPK↑ → TXNIP↓ → caspase-1↓ → IL-1β and IL-18↓ → pyroptosis↓. In general, our study identified Exendin-4 as a pyroptotic inhibitor protecting against hyperglycemia-induced cardiomyocyte pyroptosis via the AMPK-TXNIP pathway.

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