scholarly journals SARS-CoV-2 N promotes the NLRP3 inflammasome activation to induce hyperinflammation

2020 ◽  
Author(s):  
Pan Pan ◽  
Miaomiao Shen ◽  
Zhenyang Yu ◽  
Weiwei Ge ◽  
Keli Chen ◽  
...  
Keyword(s):  
Lung Injury ◽  
Nlrp3 Inflammasome ◽  
Cultured Cells ◽  
Inflammatory Responses ◽  
Pathological Process ◽  
Inflammasome Activation ◽  
N Protein ◽  
Distinct Mechanism ◽  
Nlrp3 Inflammasome Activation ◽  
Proinflammatory Responses

Abstract Excessive inflammatory responses induced upon SARS-CoV-2 infection interlocks with severe symptoms and acute lung injury in patients with Severe Coronavirus Disease 2019 (COVID-19). Revealing the mechanism underlying the control of SARS-CoV-2-triggered immune-inflammatory responses would help us to understand the pathological process and guide clinical treatment. However, the effect of the NLRP3 inflammasome on regulating SARS-CoV-2-induced inflammatory responses has not been reported. Here, we revealed a distinct mechanism by which SARS-CoV-2 nucleocapsid (N) protein promotes the NLRP3 inflammasome activation to induce hyperinflammation. We demonstrated that N protein facilitates the maturation of proinflammatory cytokines IL-1β and IL-6 and induces proinflammatory responses in cultured cells and mice tissues. In team of molecular mechanism, N protein interacts directly with NLRP3 protein, promotes the binding of NLRP3 with ASC, and facilitates the assemble of the inflammasome complex. More importantly, N protein aggravates lung injury, accelerated death in sepsis and acute inflammation mouse models, and promotes IL-1β and IL-6 activation in mice. Notably, N-induced lung injury and cytokine production were blocked by Ac-YVAD-cmk, an inhibitor of the NLRP3 inflammasome. Therefore, this study revealed a distinct mechanism by which SARS-CoV-2 N protein promotes the NLRP3 inflammasome activation and induces excessive inflammatory responses.

scholarly journals SARS-CoV-2 N protein promotes NLRP3 inflammasome activation to induce hyperinflammation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pan Pan ◽  
Miaomiao Shen ◽  
Zhenyang Yu ◽  
Weiwei Ge ◽  
Keli Chen ◽  
...  
Keyword(s):  
Lung Injury ◽  
Nlrp3 Inflammasome ◽  
Cultured Cells ◽  
Inflammatory Responses ◽  
Specific Inhibitor ◽  
Inflammasome Activation ◽  
N Protein ◽  
Distinct Mechanism ◽  
Nlrp3 Inflammasome Activation ◽  
Proinflammatory Responses

AbstractExcessive inflammatory responses induced upon SARS-CoV-2 infection are associated with severe symptoms of COVID-19. Inflammasomes activated in response to SARS-CoV-2 infection are also associated with COVID-19 severity. Here, we show a distinct mechanism by which SARS-CoV-2 N protein promotes NLRP3 inflammasome activation to induce hyperinflammation. N protein facilitates maturation of proinflammatory cytokines and induces proinflammatory responses in cultured cells and mice. Mechanistically, N protein interacts directly with NLRP3 protein, promotes the binding of NLRP3 with ASC, and facilitates NLRP3 inflammasome assembly. More importantly, N protein aggravates lung injury, accelerates death in sepsis and acute inflammation mouse models, and promotes IL-1β and IL-6 activation in mice. Notably, N-induced lung injury and cytokine production are blocked by MCC950 (a specific inhibitor of NLRP3) and Ac-YVAD-cmk (an inhibitor of caspase-1). Therefore, this study reveals a distinct mechanism by which SARS-CoV-2 N protein promotes NLRP3 inflammasome activation and induces excessive inflammatory responses.

scholarly journals Inhibition of IP3R/Ca2+ Dysregulation Protects Mice From Ventilator-Induced Lung Injury via Endoplasmic Reticulum and Mitochondrial Pathways

2021 ◽  
Vol 12 ◽  
Author(s):  
Liu Ye ◽  
Qi Zeng ◽  
Maoyao Ling ◽  
Riliang Ma ◽  
Haishao Chen ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Lung Injury ◽  
Er Stress ◽  
Mitochondrial Dysfunction ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Inflammasome Activation ◽  
Dependent Manner ◽  
Ventilator Induced Lung Injury ◽  
Nlrp3 Inflammasome Activation

RationaleDisruption of intracellular calcium (Ca2+) homeostasis is implicated in inflammatory responses. Here we investigated endoplasmic reticulum (ER) Ca2+ efflux through the Inositol 1,4,5-trisphosphate receptor (IP3R) as a potential mechanism of inflammatory pathophysiology in a ventilator-induced lung injury (VILI) mouse model.MethodsC57BL/6 mice were exposed to mechanical ventilation using high tidal volume (HTV). Mice were pretreated with the IP3R agonist carbachol, IP3R inhibitor 2-aminoethoxydiphenyl borate (2-APB) or the Ca2+ chelator BAPTA-AM. Lung tissues and bronchoalveolar lavage fluid (BALF) were collected to measure Ca2+ concentrations, inflammatory responses and mRNA/protein expression associated with ER stress, NLRP3 inflammasome activation and inflammation. Analyses were conducted in concert with cultured murine lung cell lines.ResultsLungs from mice subjected to HTV displayed upregulated IP3R expression in ER and mitochondrial-associated-membranes (MAMs), with enhanced formation of MAMs. Moreover, HTV disrupted Ca2+ homeostasis, with increased flux from the ER to the cytoplasm and mitochondria. Administration of carbachol aggravated HTV-induced lung injury and inflammation while pretreatment with 2-APB or BAPTA-AM largely prevented these effects. HTV activated the IRE1α and PERK arms of the ER stress signaling response and induced mitochondrial dysfunction-NLRP3 inflammasome activation in an IP3R-dependent manner. Similarly, disruption of IP3R/Ca2+ in MLE12 and RAW264.7 cells using carbachol lead to inflammatory responses, and stimulated ER stress and mitochondrial dysfunction.ConclusionIncrease in IP3R-mediated Ca2+ release is involved in the inflammatory pathophysiology of VILI via ER stress and mitochondrial dysfunction. Antagonizing IP3R/Ca2+ and/or maintaining Ca2+ homeostasis in lung tissue represents a prospective treatment approach for VILI.

scholarly journals STING recruits NLRP3 to the ER and deubiquitinates NLRP3 to activate the inflammasome

2019 ◽  
Author(s):  
Wenbiao Wang ◽  
Dingwen Hu ◽  
Yuqian Feng ◽  
Caifeng Wu ◽  
Aixin Li ◽  
...  
Keyword(s):  
Immune Responses ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Innate Immune ◽  
Inflammasome Activation ◽  
Primary Cells ◽  
Innate Immune Responses ◽  
Distinct Mechanism ◽  
Nlrp3 Inflammasome Activation ◽  
Pro Inflammatory Cytokines

AbstractOne of the fundamental reactions of the innate immune responses to pathogen infection is the release of pro-inflammatory cytokines, including IL-1β, processed by the NLRP3 inflammasome. STING is essential for innate immune responses and inflammasome activation. Here we reveal a distinct mechanism by which STING regulates the NLRP3 inflammasome activation, IL-1β secretion, and inflammatory responses in human cell lines, mice primary cells, and mice. Interestingly, upon HSV-1 infection and cytosolic DNA stimulation, STING binds to NLRP3 and promotes the inflammasome activation through two approaches. First, STING recruits NLRP3 and promotes NLRP3 translocation to the endoplasmic reticulum, thereby facilitating the inflammasome formation. Second, STING interacts with NLRP3 and removes K48- and K63-linked polyubiquitination of NLRP3, thereby promoting the inflammasome activation. Collectively, we demonstrate that the cGAS-STING-NLRP3 signaling is essential for host defense against DNA virus infection.

scholarly journals Anapc10 Orchestrates the NLRP3 Inflammasome Activation during Cell Cycle Control

2021 ◽  
Author(s):  
Siyu Huang ◽  
Pin Wan ◽  
Shanyu Huang ◽  
Qi Xiang ◽  
Ge Yang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Cell Cycle Control ◽  
Innate Immune ◽  
Inflammasome Activation ◽  
Anaphase Promoting Complex ◽  
Distinct Mechanism ◽  
Nlrp3 Inflammasome Activation ◽  
Recognition Protein

Activation of the NLRP3 inflammasome plays a crucial role in innate immune response. During cell division, the NLRP3 inflammasome activation must be strictly controlled. Here, we discovered the anaphase promoting complex subunit 10 (Anapc10, APC10), a substrate recognition protein of the anaphase promoting complex/cyclosome (APC/C), is a critical mediator of the NLRP3 inflammasome activation. APC10 protein interacts with NLRP3, and co-localizes with NLRP3 protein in the cytoplasm. During interphase, APC10 interacts with NLRP3 to promote the NLRP3 inflammasome activation. During mitosis, APC10 disassociates from the NLRP3 inflammasome to inhibit the inflammatory responses. This study reveals a distinct mechanism by which APC10 serves as a switch of the NLRP3 inflammasome activation during cell cycle.

scholarly journals Vaspin Alleviates Osteoarthritis by Inhibiting NLRP3-mediated Inflammation

2021 ◽  
Author(s):  
Xianjie Zhu ◽  
Shiyou Dai ◽  
Baohua Xia ◽  
Jianbao Gong ◽  
Bingzheng Ma
Keyword(s):  
Nlrp3 Inflammasome ◽  
Wistar Rat ◽  
Cartilage Degradation ◽  
Pathological Process ◽  
Inflammasome Activation ◽  
Protective Effects ◽  
Collagen Formation ◽  
Nlrp3 Inflammasome Activation

Abstract Background:Osteoarthritis (OA) is a chronic degenerative joint bone disease characterized by cartilage degradation. Visceral adipose tissue-derived serine protease inhibitor (vaspin) is associated with the inflammatory and metabolic responses to OA. However, the underlying mechanisms of the pathological process of OA are not clear. The aim of the present study was to examine the protective effects of vaspin both in vitro and in vivo.Methods:Monosodium iodoacetate (MIA)-induced Wistar rat model of OA was used to assess the in vivo effects of vaspin administered for 12 weeks. The characteristics of OA were evaluated by haematoxylin and eosin (H&E) and safranin O/fast green staining. The anti-inflammatory effect of vaspin was assessed using immunohistochemical, qRT-PCR, and western blotting analysis. Parallel experiments to detect the molecular mechanism through which vaspin prevents OA were performed using LPS-treated chondrocytes.Results:Our results showed that the degeneration of cartilage and upregulated expression of matrix metalloproteinase (MMP)-1 and MMP-13 were ameliorated by vaspin. Additionally, vaspin suppressed the activation of TXNIP/NLRP3 and secretion of tumor necrosis factor ɑ and interleukin-1β in vivo. It was further confirmed that vaspin could also suppress LPS-induced NLRP3 inflammasome activation and reduce collagen formation in chondrocytes. Moreover, vaspin inhibited NLRP3 inflammasome activation by suppressing the ROS/TXNIP pathway.Conclusions: Vaspin inhibited OA by repressing TXNIP/NLRP3 activation in in vitro and in vivo models of OA, thus providing a novel therapeutic strategy for OA.

scholarly journals A novel function of NLRP3 independent of inflammasome as a key transcription factor of IL-33 in epithelial cells of atopic dermatitis

2021 ◽  
Vol 12 (10) ◽  
Author(s):  
Jie Zheng ◽  
Lu Yao ◽  
Yijing Zhou ◽  
Xiaoqun Gu ◽  
Can Wang ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Atopic Dermatitis ◽  
Epithelial Cells ◽  
Mrna Expression ◽  
Nlrp3 Inflammasome ◽  
Myeloid Cells ◽  
Pathological Process ◽  
Inflammasome Activation ◽  
Mice Model ◽  
Nlrp3 Inflammasome Activation

AbstractAtopic dermatitis (AD) is a common chronic pruritic inflammatory skin disorder characterized by recurrent eczematous lesions. Interleukin (IL)−33, a cytokine of the IL-1 family, was found to play an important role in the pathogenesis of AD. As a key component of the inflammasome, NLRP3 has been mostly described in myeloid cells that to mediate inflammasome activation conducted proinflammatory cytokine production of the IL-1 family. However, the role of NLRP3 inflammasome in the pathogenesis of AD, as well as IL-33 processing are highly controversial. Whether NLRP3 can mediate IL-33 expression and secretion independently of the inflammasome in the epithelium of AD has remained unclear. In this article, we found the mRNA expression of Il33 and Nlrp3 were notably increased in the lesional skin of AD patients compared to healthy controls. We then found a significant positive correlation between the expression of Nlrp3 and Il33 in the epithelium of MC903-mediated AD mice model, but no changes were observed for Il36α, Il36γ, Il1β, or Il18 mRNA expression, as well as IL-1β or IL-18 production. Overexpression of NLRP3 in human immortalized epithelial cells increased IL-33 expression, whereas siRNA targeting NLRP3 abolished IL-33 expression. In addition, inhibition of NLRP3 inflammasome activation or caspase-1 activity with MCC950 or VX-765 showed no effect on the expression and secretion of IL-33 in AD mice. Unlike myeloid cells, NLRP3 predominantly located in the nucleus of epithelial cells, which could directly bind to Il33 specific-promoters and transactivate it through an interaction with transcription factor IRF4. Furthermore, NLRP3 deficient mice exhibited a significant alleviated epidermis inflammation and decreased mRNA expression and secretion of IL-33 in MC903-mediated AD mice without interfering with TSLP and IL-1β production. Our results demonstrate a novel ability of NLRP3 to function as a crucial transcription factor of IL-33 in epithelium independently of inflammasome that to mediate the pathological process of AD.

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 Extracellular mitochondrial DNA promote NLRP3 inflammasome activation and induce acute lung injury through TLR9 and NF-κB

2019 ◽  
Vol 11 (11) ◽  
pp. 4816-4828 ◽  
Author(s):  
Guannan Wu ◽  
Qingqing Zhu ◽  
Junli Zeng ◽  
Xiaoling Gu ◽  
Yingying Miao ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation
Sign in / Sign up

Export Citation Format

Share Document