scholarly journals Dual Role of Caspase-11 in Mediating Activation of Caspase-1 and Caspase-3 under Pathological Conditions

2000 ◽  
Vol 149 (3) ◽  
pp. 613-622 ◽  
Author(s):  
Shin-Jung Kang ◽  
Suyue Wang ◽  
Hideaki Hara ◽  
Erin P. Peterson ◽  
Shobu Namura ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Artery Occlusion ◽  
Caspase 1 ◽  
Pathological Conditions ◽  
Positional Scanning ◽  
Caspase Family ◽  
Cerebral Artery Occlusion ◽  
Deficient Mice

Caspase-11, a member of the murine caspase family, has been shown to be an upstream activator of caspase-1 in regulating cytokine maturation. We demonstrate here that in addition to its defect in cytokine maturation, caspase-11–deficient mice have a reduced number of apoptotic cells and a defect in caspase-3 activation after middle cerebral artery occlusion (MCAO), a mouse model of stroke. Recombinant procaspase-11 can autoprocess itself in vitro. Purified active recombinant caspase-11 cleaves and activates procaspase-3 very efficiently. Using a positional scanning combinatorial library method, we found that the optimal cleavage site of caspase-11 was (I/L/V/P)EHD, similar to that of upstream caspases such as caspase-8 and -9. Our results suggest that caspase-11 is a critical initiator caspase responsible for the activation of caspase-3, as well as caspase-1 under certain pathological conditions.

scholarly journals Role of TLR4 (Toll-Like Receptor 4) in N1/N2 Neutrophil Programming After Stroke

Stroke ◽  
2019 ◽  
Vol 50 (10) ◽  
pp. 2922-2932 ◽  
Author(s):  
Alicia García-Culebras ◽  
Violeta Durán-Laforet ◽  
Carolina Peña-Martínez ◽  
Ana Moraga ◽  
Ivan Ballesteros ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Microarray Analysis ◽  
Artery Occlusion ◽  
Toll Like Receptor ◽  
Cdna Microarray Analysis ◽  
Toll Like Receptor 4 ◽  
Cerebral Artery Occlusion ◽  
Deficient Mice

Background and Purpose— After stroke, the population of infiltrated neutrophils in the brain is heterogeneous, including a population of alternative neutrophils (N2) that express M2 phenotype markers. We explored the role of TLR4 (toll-like receptor 4) on neutrophil infiltration and polarization in this setting. Methods— Focal cerebral ischemia was induced by occlusion of the middle cerebral artery occlusion in TLR4-KO and WT (wild type) mice. Infarct size was measured by Nissl staining and magnetic resonance imaging. Leukocyte infiltration was quantified 48 hours after middle cerebral artery occlusion by immunofluorescence and flow cytometry. To elucidate mechanisms underlying TLR4-mediated N2 phenotype, a cDNA microarray analysis was performed in neutrophils isolated from blood 48 hours after stroke in WT and TLR4-KO mice. Results— As demonstrated previously, TLR4-deficient mice presented lesser infarct volumes than WT mice. TLR4-deficient mice showed higher density of infiltrated neutrophils 48 hours after stroke compared with WT mice, concomitantly to neuroprotection. Furthermore, cytometric and stereological analyses revealed an increased number of N2 neutrophils (YM1 + cells) into the ischemic core in TLR4-deficient mice, suggesting a protective effect of this neutrophil subset that was corroborated by depleting peripheral neutrophils or using mice with TLR4 genetically ablated in the myeloid lineage. Finally, cDNA microarray analysis in neutrophils, confirmed by quantitative polymerase chain reaction, showed that TLR4 modulates several pathways associated with ischemia-induced inflammation, migration of neutrophils into the parenchyma, and their functional priming, which might explain the opposite effect on outcome of the different neutrophil subsets. Conclusions— TLR4 deficiency increased the levels of alternative neutrophils (N2)—an effect associated with neuroprotection after stroke—supporting that modulation of neutrophil polarization is a major target of TLR4 and highlighting the crucial role of TLR4 at the peripheral level after stroke. Visual Overview— An online visual overview is available for this article.

scholarly journals Gasdermin E deficiency attenuates acute kidney injury by inhibiting pyroptosis and inflammation

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Weiwei Xia ◽  
Yuanyuan Li ◽  
Mengying Wu ◽  
Qianqian Jin ◽  
Qian Wang ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Caspase 3 ◽  
Inflammatory Diseases ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Tubular Epithelial Cells ◽  
Regulated Cell Death ◽  
Deficient Mice

AbstractPyroptosis, one kind of inflammatory regulated cell death, is involved in various inflammatory diseases, including acute kidney injury (AKI). Besides Gasdermin D (GSDMD), GSDME is a newly identified mediator of pyroptosis via the cleavage of caspase-3 generating pyroptotic GSDME-N. Here, we investigated the role of GSDME in renal cellular pyroptosis and AKI pathogenesis employing GSDME-deficient mice and human tubular epithelial cells (TECs) with the interventions of pharmacological and genetic approaches. After cisplatin treatment, GSDME-mediated pyroptosis was induced as shown by the characteristic pyroptotic morphology in TECs, upregulated GSDME-N expression and enhanced release of IL-1β and LDH, and decreased cell viability. Strikingly, silencing GSDME in mice attenuated acute kidney injury and inflammation. The pyroptotic role of GSDME was also verified in human TECs in vitro. Further investigation showed that inhibition of caspase-3 blocked GSDME-N cleavage and attenuated cisplatin-induced pyroptosis and kidney dysfunction. Moreover, deletion of GSDME also protected against kidney injury induced by ischemia-reperfusion. Taken together, the findings from current study demonstrated that caspase-3/GSDME-triggered pyroptosis and inflammation contributes to AKI, providing new insights into the understanding and treatment of this disease.

Abstract 13493: Complete Disruption of All Nitric Oxide Synthase Genes Markedly Reduces Cerebral Infarct Size after Middle Cerebral Artery Occlusion in Mice

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Masato Tsutsui ◽  
Haruaki Kubota ◽  
Katsuhiko Noguchi ◽  
Toshihiro Matsuzaki ◽  
Fumiya Hattori ◽  
...  
Keyword(s):  
Cerebral Infarction ◽  
Infarct Size ◽  
Artery Occlusion ◽  
Cerebral Infarct ◽  
Wild Type ◽  
Complete Disruption ◽  
Oxide Synthase ◽  
Cerebral Artery Occlusion ◽  
Deficient Mice

Background: The role of each nitric oxide synthase (NOS) isoform in the pathogenesis of cerebral infarction has been studied in individual NOS isoform-deficient mice. It has been reported that, in a model of middle cerebral artery occlusion (MCAO), neuronal and inducible NOSs exacerbate cerebral infarction, whereas endothelial NOS conversely alleviates cerebral infarction. Although the role of the whole NOSs system in cerebral infarction has been examined in pharmacological studies with non-selective NOS inhibitors, the results are quit inconsistent, possibly because of non-specificity of the agents. In this study, we addressed this point in mice in which all three NOS genes are completely disrupted. Method and Results: We newly generated triple NOSs-deficient mice and wild-type littermates by crossbreeding single NOS -/- mice. Transient (1 hour) and permanent MCAO was performed in male triple NOSs -/- and wild-type mice at 8-12 weeks of age (n=9-11). Cerebral infarct size was evaluated by triphenyltetrazolium chloride (TTC) staining. There was no anatomical difference in the structure of cerebral arteries between the triple NOSs -/- and wild-type mice (n=3 each). Reductions in cerebral blood flow during MCAO were identical between the two mice. However, cerebral infarct size at 24 hours after transient MCAO was markedly smaller in the triple NOSs -/- than in the wild-type mice ( P <0.05, n=8-12). Cerebral infarct size at 24 hours after permanent MCAO was also markedly decreased in the triple NOSs -/- mice as compared with the wild-type mice ( P <0.05, n=8-10). In addition, neurological deficit was significantly less and the survival rate was significantly better in the triple NOSs -/- mice compared with the wild-type mice (both P <0.05, n=8-12). Conclusions: These results provide the first evidence that complete disruption of all NOS genes markedly reduces cerebral infarct size after MCAO in mice, demonstrating a novel injurious role of the entire NOSs system in cerebral infarction. Inhibition of the NOSs system may be a novel therapeutic option in the treatment of cerebral infarction.

scholarly journals Neuroprotective Role of Lactate after Cerebral Ischemia

2009 ◽  
Vol 29 (11) ◽  
pp. 1780-1789 ◽  
Author(s):  
Carole Berthet ◽  
Hongxia Lei ◽  
Jonathan Thevenet ◽  
Rolf Gruetter ◽  
Pierre J Magistretti ◽  
...  
Keyword(s):  
Hippocampal Slices ◽  
Glucose Deprivation ◽  
Lesion Size ◽  
Artery Occlusion ◽  
Neurologic Outcome ◽  
Moderate Increase ◽  
Cerebral Artery Occlusion

It is well established that lactate can be used as an energy substrate by the brain by conversion to pyruvate and a subsequent oxidation in the mitochondria. Knowing the need for readily metabolizable substrates directly after ischemia and the protective effect of lactate after excitotoxicity, the aim of this study was to investigate whether lactate administration directly after ischemia could be neuroprotective. In vitro, the addition of 4 mmol/L l-lactate to the medium of rat organotypic hippocampal slices, directly after oxygen and glucose deprivation (OGD), protected against neuronal death, whereas a higher dose of 20 mmol/L was toxic. In vivo, after middle cerebral artery occlusion in the mouse, an intracerebroventricular injection of 2 μL of 100 mmol/L l-lactate, immediately after reperfusion, led to a significant decrease in lesion size, which was more pronounced in the striatum, and an improvement in neurologic outcome. A later injection 1 h after reperfusion did not reduce lesion size, but significantly improved neurologic outcome, which is an important point in the context of a potential clinical application. Therefore, a moderate increase in lactate after ischemia may be a therapeutic tool.

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 20-HETE-mediated cytotoxicity and apoptosis in ischemic kidney epithelial cells

2008 ◽  
Vol 294 (3) ◽  
pp. F562-F570 ◽  
Author(s):  
Vani Nilakantan ◽  
Cheryl Maenpaa ◽  
Guangfu Jia ◽  
Richard J. Roman ◽  
Frank Park
Keyword(s):  
Caspase 3 ◽  
Fluorescent Protein ◽  
Ischemia Reperfusion ◽  
Atp Depletion ◽  
Cellular Damage ◽  
Apoptotic Pathway ◽  
Injury Model ◽  
Green Fluorescent

20-HETE, a metabolite of arachidonic acid, has been implicated as a mediator of free radical formation and tissue death following ischemia-reperfusion (IR) injury in the brain and heart. The present study examined the role of this pathway in a simulated IR renal injury model in vitro. Modified self-inactivating lentiviral vectors were generated to stably overexpress murine Cyp4a12 following transduction into LLC-PK1 cells (LLC-Cyp4a12). We compared the survival of control and transduced LLC-PK1 cells following 4 h of ATP depletion and 2 h of recovery in serum-free medium. ATP depletion-recovery of LLC-Cyp4a12 cells resulted in a significantly higher LDH release ( P < 0.05) compared with LLC-enhanced green fluorescent protein (EGFP) cells. Treatment with the SOD mimetic MnTMPyP (100 μM) resulted in decreased cytotoxicity in LLC-Cyp4a12 cells. The selective 20-HETE inhibitor HET-0016 (10 μM) also inhibited cytotoxicity significantly ( P < 0.05) in LLC-Cyp4a12 cells. Dihydroethidium fluorescence showed that superoxide levels were increased to the same degree in LLC-EGFP and LLC-Cyp4a12 cells after ATP depletion-recovery compared with control cells and that this increase was inhibited by MnTMPyP. There was a significant increase ( P < 0.05) of caspase-3 cleavage, an effector protease of the apoptotic pathway, in the LLC-Cyp4a12 vs. LLC-EGFP cells ( P < 0.05). This was abolished in the presence of HET-0016 ( P < 0.05) or MnTMPyP ( P < 0.01). These results demonstrate that 20-HETE overexpression can significantly exacerbate the cellular damage that is associated with renal IR injury and that the programmed cell death is mediated by activation of caspase-3 and is partially dependent on enhanced CYP4A generation of free radicals.

scholarly journals Extracellular vesicles package dsDNA to aggravate Crohn’s disease by activating the STING pathway

2021 ◽  
Vol 12 (9) ◽  
Author(s):  
Fan Zhao ◽  
Tao Zheng ◽  
Wenbin Gong ◽  
Jie Wu ◽  
Haohao Xie ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Extracellular Vesicles ◽  
Intestinal Inflammation ◽  
Therapeutic Effects ◽  
Murine Colitis ◽  
Sting Pathway ◽  
Deficient Mice

AbstractCrohn’s disease (CD) is an intestinal immune-dysfunctional disease. Extracellular vesicles (EVs) are membrane-enclosed particles full of functional molecules, e.g., nuclear acids. Recently, EVs have been shown to participate in the development of CD by realizing intercellular communication among intestinal cells. However, the role of EVs carrying double-strand DNA (dsDNA) shed from sites of intestinal inflammation in CD has not been investigated. Here we isolated EVs from the plasma or colon lavage of murine colitis and CD patients. The level of exosomal dsDNA, including mtDNA and nDNA, significantly increased in murine colitis and active human CD, and was positively correlated with the disease activity. Moreover, the activation of the STING pathway was verified in CD. EVs from the plasma of active human CD triggered STING activation in macrophages in vitro. EVs from LPS-damaged colon epithelial cells were also shown to raise inflammation in macrophages via activating the STING pathway, but the effect disappeared after the removal of exosomal dsDNA. These findings were further confirmed in STING-deficient mice and macrophages. STING deficiency significantly ameliorated colitis. Besides, potential therapeutic effects of GW4869, an inhibitor of EVs release were assessed. The application of GW4869 successfully ameliorated murine colitis by inhibiting STING activation. In conclusion, exosomal dsDNA was found to promote intestinal inflammation via activating the STING pathway in macrophages and act as a potential mechanistic biomarker and therapeutic target of CD.

Abstract TMP25: Long Non-Coding RNA Mediates Stroke-Induced Neurogenesis

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Baoyan Fan ◽  
Wanlong Pan ◽  
Xinli Wang ◽  
Michael Chopp ◽  
Zheng Gang Zhang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Regulation Of Gene Expression ◽  
Artery Occlusion ◽  
Loss Of Function ◽  
Bioinformatics Analyses ◽  
Guide Rna ◽  
Non Coding Rna ◽  
Cerebral Artery Occlusion ◽  
Long Non Coding Rna

Background and Purpose: Adult neurogenesis contributes to functional recovery after stroke. Long non-coding RNAs (lncRNAs) regulate stem cell self-renewal and differentiation. However, the role of lncRNAs in stroke-induced neurogenesis remains unknown. Methods and Results: Using lncRNA array and in situ hybridization, we analyzed lncRNA profiles of adult neural stem cells (NSCs) isolated from the subventricular zone neurogenic region in rats subjected to middle cerebral artery occlusion. We found that H19 was the most highly upregulated lncRNA (19 fold) in ischemic NSCs compared with non-ischemic NSCs. Reduction of endogenous H19 in NSCs by CRISPR-Cas9 genome editing significantly decreased the proliferation and increased the apoptosis of ischemic NSCs, as assayed by the number of BrdU + cells (56±5% vs 22±3%, p<0.01, n=3) and Caspase-3/7 activity compared to NSCs transfected with scrambled small guide RNA (sgRNA). Knockdown of H19 significantly decreased the number of Tuj1 + neuroblasts (8±2% vs 5±0.4%, p<0.01, n=3) and NG 2 + oliogodendrocyte progenitor cells (10±1% vs 5±0.3%, p<0.01, n=3), suggesting that deletion of H19 suppresses the proliferation and survival and blocks the differentiation of NSCs into neurons and oligodendrocytes. Additional RNA-sequencing and bioinformatics analyses revealed that genes deregulated by H19 knockdown were involved in transcription, apoptosis, proliferation, cell cycle and response to hypoxia. Western blot analysis validated that loss-of-function and gain-of-function of H19 significantly increased and reduced, respectively, the transcription of cell cycle-related genes including p27. Using ChIRP assay, we found that upregulated H19 in NSCs was physically associated with EZH2 which catalyzes the repressive H3K27me3 histone marker. Knockdown of H19 significantly reduced the enrichment of H3K27me3 at the promoter of p27, leading to the upregulation of p27 expression and consequently inhibition of NSC proliferation. Conclusions: H19 mediates stroke-induced neurogenesis by regulating genes involved in cell cycle and survival through the interaction with chromatin remodeling proteins. Our data provide novel insights into epigenetic regulation of gene expression by lncRNA in neurogenesis.

scholarly journals Inhibition of Prostate Cancer DU-145 Cells Proliferation by Anthopleura anjunae Oligopeptide (YVPGP) via PI3K/AKT/mTOR Signaling Pathway

Marine Drugs ◽  
2018 ◽  
Vol 16 (9) ◽  
pp. 325 ◽  
Author(s):  
Xiaojuan Li ◽  
Yunping Tang ◽  
Fangmiao Yu ◽  
Yu Sun ◽  
Fangfang Huang ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Signaling Pathway ◽  
Caspase 3 ◽  
Mtor Signaling ◽  
Mtor Signaling Pathway ◽  
Nude Mouse Model ◽  
Dose Dependent

We investigated the antitumor mechanism of Anthopleura anjunae oligopeptide (AAP-H, YVPGP) in prostate cancer DU-145 cells in vitro and in vivo. Results indicated that AAP-H was nontoxic and exhibited antitumor activities. Cell cycle analysis indicated that AAP-H may arrest DU-145 cells in the S phase. The role of the phosphatidylinositol 3-kinase/protein kinase B/mammalian rapamycin target protein (PI3K/AKT/mTOR) signaling pathway in the antitumor mechanism of APP-H was investigated. Results showed that AAP-H treatment led to dose-dependent reduction in the levels of p-AKT (Ser473), p-PI3K (p85), and p-mTOR (Ser2448), whereas t-AKT and t-PI3K levels remained unaltered compared to the untreated DU-145 cells. Inhibition of PI3K/AKT/mTOR signaling pathway in the DU-145 cells by employing inhibitor LY294002 (10 μM) or rapamycin (20 nM) effectively attenuated AAP-H-induced phosphorylation of AKT and mTOR. At the same time, inhibitor addition further elevated AAP-H-induced cleaved-caspase-3 levels. Furthermore, the effect of AAP-H on tumor growth and the role of the PI3K/AKT/mTOR signaling pathway in nude mouse model were also investigated. Immunohistochemical analysis showed that activated AKT, PI3K, and mTOR levels were reduced in DU-145 xenografts. Western blotting showed that AAP-H treatment resulted in dose-dependent reduction in p-AKT (Ser473), p-PI3K (p85), and p-mTOR (Ser2448) levels, whereas t-AKT and t-PI3K levels remained unaltered. Similarly, Bcl-xL levels decreased, whereas that of Bax increased after AAP-H treatment. AAP-H also increased initiator (caspase 8 and 9) and executor caspase (caspase 3 and 7) levels. Therefore, the antitumor mechanism of APP-H on DU-145 cells may involve regulation of the PI3K/AKT/mTOR signaling pathway, which eventually promotes apoptosis via mitochondrial and death receptor pathways. Thus, the hydrophobic oligopeptide (YVPGP) can be developed as an adjuvant for the prevention or treatment of prostate cancer in the future.

The use of siRNA as a pharmacological tool to assess a role for the transcription factor NF-IL6 in the brain under in vitro and in vivo conditions during LPS-induced inflammatory stimulation

2017 ◽  
Vol 28 (6) ◽  
Author(s):  
Jelena Damm ◽  
Joachim Roth ◽  
Rüdiger Gerstberger ◽  
Christoph Rummel
Keyword(s):  
Transcription Factor ◽  
Brain Cells ◽  
Nuclear Factor ◽  
Si Rna ◽  
The Brain ◽  
Deficient Mice ◽  
Transcription Factor Nuclear Factor

AbstractBackground:Studies with NF-IL6-deficient mice indicate that this transcription factor plays a dual role during systemic inflammation with pro- and anti-inflammatory capacities. Here, we aimed to characterize the role of NF-IL6 specifically within the brain.Methods:In this study, we tested the capacity of short interfering (si) RNA to silence the inflammatory transcription factor nuclear factor-interleukin 6 (NF-IL6) in brain cells underResults:In cells of a mixed neuronal and glial primary culture from the ratConclusions:This approach was, thus, not suitable to characterize the role NF-IL6 in the brain

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