scholarly journals Trichomonas vaginalis Induces NLRP3 Inflammasome Activation and Pyroptotic Cell Death in Human Macrophages

2018 ◽  
Vol 11 (1) ◽  
pp. 86-98 ◽  
Author(s):  
Angelica Montenegro Riestra ◽  
J. Andrés Valderrama ◽  
Kathryn A. Patras ◽  
Sharon D. Booth ◽  
Xing Yen Quek ◽  
...  
Keyword(s):  
Cell Death ◽  
Host Cell ◽  
Nlrp3 Inflammasome ◽  
Trichomonas Vaginalis ◽  
Inflammasome Activation ◽  
Cell Detection ◽  
Human Macrophages ◽  
Sexually Transmitted ◽  
Caspase 1 ◽  
Nlrp3 Inflammasome Activation

Trichomonas vaginalis is a sexually transmitted, eukaryotic parasite that causes trichomoniasis, the most common nonviral, sexually transmitted disease in the USA and worldwide. Little is known about the molecular mechanisms involved in the host immune response to this widespread parasite. Here we report that T. vaginalis induces NLRP3 inflammasome activation in human macrophages, leading to caspase-1 activation and the processing of pro-IL-1β to the mature and bioactive form of the cytokine. Using inhibitor-based approaches, we show that NLRP3 activation by T. vaginalis involves host cell detection of extracellular ATP via P2X7 receptors and potassium efflux. In addition, our data reveal that T. vaginalis inflammasome activation induces macrophage inflammatory cell death by pyroptosis, known to occur via caspase-1 cleavage of the gasdermin D protein, which assembles to form pores in the host cell membrane. We found that T. vaginalis-induced cytolysis of macrophages is attenuated in gasdermin D knockout cells. Lastly, in a murine challenge model, we detected IL-1β production in vaginal fluids in response to T. vaginalis infection in vivo. Together, our findings mechanistically dissect how T. vaginalis contributes to the production of the proinflammatory IL-1β cytokine and uncover pyroptosis as a mechanism by which the parasite can trigger host macrophage cell death.

scholarly journals Lycopus lucidus Turcz exerts neuroprotective effect against H2O2‑induced neuroinflammation by inhibiting NLRP3 inflammasome activation in cortical neurons

2021 ◽  
Author(s):  
Hyunseong Kim ◽  
Jin Young Hong ◽  
Wan-Jin Jeon ◽  
Junseon Lee ◽  
Seung Ho Baek ◽  
...  
Keyword(s):  
Cell Death ◽  
Nlrp3 Inflammasome ◽  
Cortical Neurons ◽  
Neuronal Damage ◽  
Neuroprotective Effect ◽  
Synaptic Connectivity ◽  
Inflammasome Activation ◽  
Caspase 1 ◽  
Nlrp3 Inflammasome Activation ◽  
Rat Cortical Neurons

Abstract Background Central nervous system (CNS) injuries are a leading cause of permanent functional impairment in humans. Nerve damage can be aggravated by neuroinflammation mediated by protein complexes known as inflammasomes, such as the NLRP3 inflammasome which is a key mediator of caspase-1 and interleukin-1β (IL-1β) /interleukin-18 (IL-18) activation. Lycopus lucidus Turcz (LLT) is a traditional medicinal herb that exerts therapeutic effects against oxidative stress, inflammation, and angiogenesis; however, it remains unclear whether LLT can directly protect neurons against damage, and the underlying molecular mechanisms are poorly understood. Methods We investigated the neuroprotective effect of LLT against hydrogen peroxide (H2O2)-induced neuronal damage in cultured primary rat cortical neurons, as well as the potential underlying mechanisms. Neuronal viability and cell death assays were used to determine the effects of LLT on neuroprotection, while the mode of cell death was confirmed using flow cytometry. Changes in the expression of inflammatory factors involved in activation of the NLRP3 inflammasome were measured using immunocytochemistry (ICC) and confirmed by real-time PCR. And, we analyzed that the effect of LLT on neurotrophic factors secretion and synaptic connectivity using ICC in H2O2-induced neuron at 7 days in vitro. Results LLT effectively protected cultured rat cortical neurons from H2O2-induced injury by significantly inhibiting NLRP3 inflammasome activation. In addition, LLT significantly reduced caspase1 activation, which is known to be induced by inflammasome formation, and consequently regulated the secretion of IL-1β/IL-18. We demonstrated that LLT enhances axonal elongation and synaptic connectivity against H2O2-induced injury of rat primary cortical neuron. Conclusions Together, these results demonstrate that LLT can directly protect cultured cortical neurons from H2O2-induced neuronal damage by inhibiting NLRP3 inflammasome activation and the secretion of caspase-1 and IL-1β/IL-18. Thus, our study provides new insights into the therapeutic mechanisms of LLT and suggests that the NLRP3 inflammasome could be a promising target for treating neurological diseases.

scholarly journals Dimethyl Fumarate Alleviates NLRP3 Inflammasome Activation in Microglia and Sickness Behavior in LPS-Challenged Mice

2021 ◽  
Vol 12 ◽  
Author(s):  
Bora Tastan ◽  
Burak I. Arioz ◽  
Kemal Ugur Tufekci ◽  
Emre Tarakcioglu ◽  
Ceren Perihan Gonul ◽  
...  
Keyword(s):  
Cell Death ◽  
Nlrp3 Inflammasome ◽  
Forced Swim Test ◽  
Sickness Behavior ◽  
Dimethyl Fumarate ◽  
Inflammasome Activation ◽  
Caspase 1 ◽  
Nlrp3 Inflammasome Activation

NLRP3 inflammasome activation contributes to several pathogenic conditions, including lipopolysaccharide (LPS)-induced sickness behavior characterized by reduced mobility and depressive behaviors. Dimethyl fumarate (DMF) is an immunomodulatory and anti-oxidative molecule commonly used for the symptomatic treatment of multiple sclerosis and psoriasis. In this study, we investigated the potential use of DMF against microglial NLRP3 inflammasome activation both in vitro and in vivo. For in vitro studies, LPS- and ATP-stimulated N9 microglial cells were used to induce NLRP3 inflammasome activation. DMF’s effects on inflammasome markers, pyroptotic cell death, ROS formation, and Nrf2/NF-κB pathways were assessed. For in vivo studies, 12–14 weeks-old male BALB/c mice were treated with LPS, DMF + LPS and ML385 + DMF + LPS. Behavioral tests including open field, forced swim test, and tail suspension test were carried out to see changes in lipopolysaccharide-induced sickness behavior. Furthermore, NLRP3 and Caspase-1 expression in isolated microglia were determined by immunostaining. Here we demonstrated that DMF ameliorated LPS and ATP-induced NLRP3 inflammasome activation by reducing IL-1β, IL-18, caspase-1, and NLRP3 levels, reactive oxygen species formation and damage, and inhibiting pyroptotic cell death in N9 murine microglia via Nrf2/NF-κB pathways. DMF also improved LPS-induced sickness behavior in male mice and decreased caspase-1/NLRP3 levels via Nrf2 activation. Additionally, we showed that DMF pretreatment decreased miR-146a and miR-155 both in vivo and in vitro. Our results proved the effectiveness of DMF on the amelioration of microglial NLRP3 inflammasome activation. We anticipate that this study will provide the foundation consideration for further studies aiming to suppress NLRP3 inflammasome activation associated with in many diseases and a better understanding of its underlying mechanisms.

Coptisine from Coptis chinensis blocks NLRP3 inflammasome activation by inhibiting caspase-1

2019 ◽  
Vol 147 ◽  
pp. 104348 ◽  
Author(s):  
Jiasi Wu ◽  
Yu Luo ◽  
Qing Jiang ◽  
Sheng Li ◽  
Wenge Huang ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Coptis Chinensis ◽  
Caspase 1 ◽  
Nlrp3 Inflammasome Activation

scholarly journals The Essential Oil of Artemisia argyi H.Lév. and Vaniot Attenuates NLRP3 Inflammasome Activation in THP-1 Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Pengxiao Chen ◽  
Qi Bai ◽  
Yanting Wu ◽  
Qiongzhen Zeng ◽  
Xiaowei Song ◽  
...  
Keyword(s):  
Essential Oil ◽  
Nlrp3 Inflammasome ◽  
Therapeutic Potential ◽  
Inflammasome Activation ◽  
Caspase 1 ◽  
Artemisia Argyi ◽  
Nlrp3 Inflammasome Activation ◽  
Long Time

Artemisia argyi H. Lév. and Vaniot is a traditional medical herb that has been used for a long time in China and other Asian counties. Essential oil is the main active fraction of Artemisia argyi H. Lév. and Vaniot, and its anti-inflammatory potential has been observed in vitro and in vivo. Here, we found that the essential oil of Artemisia argyi H. Lév. and Vaniot (EOAA) inhibited monosodium urate (MSU)- and nigericin-induced NLRP3 inflammasome activation. EOAA suppressed caspase-1 and IL-1β processing and pyroptosis. NF-κB p65 phosphorylation and translocation were also inhibited. In addition, EOAA suppressed nigericin-induced NLRP3 inflammasome activation without blocking ASC oligomerization, suggesting that it may inhibit NLRP3 inflammasome activation by preventing caspase-1 processing. Our study thus indicates that EOAA inhibits NLRP3 inflammasome activation and has therapeutic potential against NLRP3-driven diseases.

scholarly journals Heterogeneous NLRP3 inflammasome signature in circulating myeloid cells as a biomarker of COVID-19 severity

2021 ◽  
Vol 5 (5) ◽  
pp. 1523-1534
Author(s):  
Johan Courjon ◽  
Océane Dufies ◽  
Alexandre Robert ◽  
Laurent Bailly ◽  
Cédric Torre ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Myeloid Cells ◽  
Inflammasome Activation ◽  
Caspase 1 ◽  
Molecular Pattern ◽  
Nlrp3 Inflammasome Activation ◽  
Healthy Donors ◽  
Activation Potential ◽  
Key Factor ◽  
Pathogen Associated Molecular Pattern

Abstract Dysregulated immune response is the key factor leading to unfavorable coronavirus disease 2019 (COVID-19) outcome. Depending on the pathogen-associated molecular pattern, the NLRP3 inflammasome can play a crucial role during innate immunity activation. To date, studies describing the NLRP3 response during severe acute respiratory syndrome coronavirus 2 infection in patients are lacking. We prospectively monitored caspase-1 activation levels in peripheral myeloid cells from healthy donors and patients with mild to critical COVID-19. The caspase-1 activation potential in response to NLRP3 inflammasome stimulation was opposed between nonclassical monocytes and CD66b+CD16dim granulocytes in severe and critical COVID-19 patients. Unexpectedly, the CD66b+CD16dim granulocytes had decreased nigericin-triggered caspase-1 activation potential associated with an increased percentage of NLRP3 inflammasome impaired immature neutrophils and a loss of eosinophils in the blood. In patients who recovered from COVID-19, nigericin-triggered caspase-1 activation potential in CD66b+CD16dim cells was restored and the proportion of immature neutrophils was similar to control. Here, we reveal that NLRP3 inflammasome activation potential differs among myeloid cells and could be used as a biomarker of a COVID-19 patient’s evolution. This assay could be a useful tool to predict patient outcome. This trial was registered at www.clinicaltrials.gov as #NCT04385017.

scholarly journals Internalization of the Membrane Attack Complex Triggers NLRP3 Inflammasome Activation and IL-1β Secretion in Human Macrophages

2021 ◽  
Vol 12 ◽  
Author(s):  
Ines Diaz-del-Olmo ◽  
Jonathan Worboys ◽  
Fatima Martin-Sanchez ◽  
Anna Gritsenko ◽  
Ashley R. Ambrose ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Pore Formation ◽  
Membrane Attack Complex ◽  
Inflammasome Activation ◽  
Adapter Protein ◽  
Human Macrophages ◽  
Danger Signals ◽  
Nlrp3 Inflammasome Activation ◽  
Golgi Network ◽  
Stimulation Of

Interleukin 1β (IL-1β) plays a major role in inflammation and is secreted by immune cells, such as macrophages, upon recognition of danger signals. Its secretion is regulated by the inflammasome, the assembly of which results in caspase 1 activation leading to gasdermin D (GSDMD) pore formation and IL-1β release. During inflammation, danger signals also activate the complement cascade, resulting in the formation of the membrane attack complex (MAC). Here, we report that stimulation of LPS-primed human macrophages with sub-lytic levels of MAC results in activation of the NOD-like receptor 3 (NLRP3) inflammasome and GSDMD-mediated IL-1β release. The MAC is first internalized into endosomes and then colocalizes with inflammasome components; adapter protein apoptosis associated speck-like protein containing a CARD (ASC) and NLRP3. Pharmacological inhibitors established that MAC-triggered activation of the NLRP3 inflammasome was dependent on MAC endocytosis. Internalization of the MAC also caused dispersion of the trans-Golgi network. Thus, these data uncover a role for the MAC in activating the inflammasome and triggering IL-1β release in human macrophages.

Psidium guajava Flavonoids Prevent NLRP3 Inflammasome Activation and Alleviate the Pancreatic Fibrosis in a Chronic Pancreatitis Mouse Model

2021 ◽  
Vol 49 (08) ◽  
pp. 2001-2015
Author(s):  
Guixian Zhang ◽  
Liming Tang ◽  
Hongbin Liu ◽  
Dawei Liu ◽  
Manxue Wang ◽  
...  
Keyword(s):  
Chronic Pancreatitis ◽  
Signaling Pathway ◽  
Nlrp3 Inflammasome ◽  
Target Genes ◽  
Inflammatory Responses ◽  
Psidium Guajava ◽  
Pancreatic Fibrosis ◽  
Inflammasome Activation ◽  
Caspase 1 ◽  
Nlrp3 Inflammasome Activation

Chronic pancreatitis (CP) is a multifactorial, inflammatory syndrome characterized by acinar atrophy and fibrosis. Activation of NOD-like receptors family pyrin domain-containing 3 (NLRP3) inflammasome is a central mediator of multiple chronic inflammatory responses and chronic fibrosis including pancreatic fibrosis in CP. The Psidium guajavaleaf is widely used in traditional medicine for the treatment of chronic inflammation, but the anti-inflammatory effect of Psidium guajavaleaf on CP has not yet been revealed. In this study, we investigated whether the extract of total flavonoids from Psidium guajava leaves (TFPGL) plays a therapeutic mechanism on CP through NLRP3 inflammasome signaling pathway in a mouse CP model. The H&E and acid-Sirius red staining indicted that TFPGL attenuated the inflammatory cell infiltration and fibrosis significantly. The results of immunohistological staining, western blot and RT-qPCR showed that the expressions of NLRP3 and caspase-1 were significantly increased in the CP model group, while TFPGL significantly decreased the NLRP3 and caspase-1 expression at both the gene and protein levels. Moreover, ELISA assay was used to examine the levels of NLRP3 inflammasome target genes, such as caspase-1, IL-1[Formula: see text] and IL-18. We found that TFPGL treatment decreased the expression of caspase-1, IL-1[Formula: see text] and IL-18, which is critical for the NLRP3 inflammasome signaling pathway and inflammation response significantly. These results demonstrated that TFPGL attenuated pancreatic inflammation and fibrosis via preventing NLRP3 inflammasome activation and TFPGL can be used as a potential therapeutic agent for CP.

scholarly journals Astragaloside IV Suppresses High Glucose-Induced NLRP3 Inflammasome Activation by Inhibiting TLR4/NF-κB and CaSR

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Bin Leng ◽  
Yingjie Zhang ◽  
Xinran Liu ◽  
Zhen Zhang ◽  
Yang Liu ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
High Glucose ◽  
Inflammasome Activation ◽  
Astragaloside Iv ◽  
Caspase 1 ◽  
Endothelial Inflammation ◽  
Nlrp3 Inflammasome Activation ◽  
Anti Inflammatory

Long-term exposure to high glucose induces vascular endothelial inflammation that can result in cardiovascular disease. Astragaloside IV (As-IV) is widely used for anti-inflammatory treatment of cardiovascular diseases. However, its mechanism of action is still not fully understood. In this study, we investigated the effect of As-IV on high glucose-induced endothelial inflammation and explored its possible mechanisms. In vivo, As-IV (40 and 80 mg/kg/d) was orally administered to rats for 8 weeks after a single intraperitoneal injection of streptozotocin (STZ, 65 mg/kg). In vitro, human umbilical vein endothelial cells (HUVECs) were treated with high glucose (33 mM glucose) in the presence or absence of As-IV, NPS2143 (CaSR inhibitor), BAY 11-7082 (NF-κB p65 inhibitor), and INF39 (NLRP3 inhibitor), and overexpression of CaSR was induced by infection of CaSR-overexpressing lentiviral vectors to further discuss the anti-inflammatory property of As-IV. The results showed that high glucose increased the expression of interleukin-18 (IL-18), interleukin-1β (IL-1β), NLRP3, caspase-1, and ASC, as well as the protein level of TLR4, nucleus p65, and CaSR. As-IV can reverse these changes in vivo and in vitro. Meanwhile, NPS2143, BAY 11-7082, and INF39 could significantly abolish the high glucose-enhanced NLRP3, ASC, caspase-1, IL-18, and IL-1β expression in vitro. In addition, both NPS2143 and BAY 11-7082 attenuated high glucose-induced upregulation of NLRP3, ASC, caspase-1, IL-18, and IL-1β expression. In conclusion, this study suggested that As-IV could inhibit high glucose-induced NLRP3 inflammasome activation and subsequent secretion of proinflammatory cytokines via inhibiting TLR4/NF-κB signaling pathway and CaSR, which provides new insights into the anti-inflammatory activity of As-IV.

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