scholarly journals OXSR1 inhibits inflammasome activation by limiting potassium efflux during mycobacterial infection

2021 ◽  
Author(s):  
Elinor Hortle ◽  
Lam Vi Tran ◽  
Angela RM Fontaine ◽  
Natalia Pinello ◽  
Justin JL Wong ◽  
...  
Keyword(s):  
Mycobacterial Infection ◽  
Inflammasome Activation ◽  
Zebrafish Embryos ◽  
Protective Effects ◽  
Bacterial Burden ◽  
Potassium Efflux ◽  
Intracellular Potassium ◽  
Nlrp3 Inflammasome Activation ◽  
Tnf Α ◽  
Intracellular Infections

Pathogenic mycobacteria inhibit inflammasome activation as part of their pathogenesis. While it is known that potassium efflux is a trigger for inflammasome activation, the interaction between mycobacterial infection, potassium efflux and inflammasome activation has not been investigated. Here we use Mycobacterium marinum infection of zebrafish embryos to demonstrate that pathogenic mycobacteria upregulate the host WNK signalling pathway kinases SPAK and OXSR1 which control intracellular potassium balance. We show that genetic depletion or inhibition of OXSR1 decreases bacterial burden and intracellular potassium levels. The protective effects of OXSR1 depletion are mediated by NLRP3 inflammasome activation and are dependent on caspase-mediated release of IL-1β and the downstream activation of protective TNF-α. The elucidation of this druggable pathway to potentiate inflammasome activation provides a new avenue for the development of host-directed therapies against intracellular infections.

scholarly journals Qingwenzhike Prescription Alleviates Acute Lung Injury Induced by LPS via Inhibiting TLR4/NF-kB Pathway and NLRP3 Inflammasome Activation

2021 ◽  
Vol 12 ◽  
Author(s):  
Cai Zhang ◽  
Xinran Wang ◽  
Chunguo Wang ◽  
Cheng He ◽  
Quantao Ma ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Inflammasome Activation ◽  
Chemical Compositions ◽  
Alveolar Wall ◽  
Protective Effects ◽  
Caspase 1 ◽  
Nlrp3 Inflammasome Activation ◽  
Tnf Α ◽  
Ifn Γ ◽  
Underlying Mechanisms

Background: Acute lung injury (ALI) is characterized by dysfunction of the alveolar epithelial membrane caused by acute inflammation and tissue injury. Qingwenzhike (QWZK) prescription has been demonstrated to be effective against respiratory viral infections in clinical practices, including coronavirus disease 2019 (COVID-19) infection. So far, the chemical compositions, protective effects on ALI, and possible anti-inflammatory mechanisms remain unknown.Methods: In this study, the compositions of QWZK were determined via the linear ion trap/electrostatic field orbital trap tandem high-resolution mass spectrometry (UHPLC-LTQ-Orbitrap MS). To test the protective effects of QWZK on ALI, an ALI model induced by lipopolysaccharide (LPS) in rats was used. The effects of QWZK on the LPS-induced ALI were evaluated by pathological changes and the number and classification of white blood cell (WBC) in bronchoalveolar lavage fluid (BALF). To investigate the possible underlying mechanisms, the contents of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein (MCP-1), interleukin-1β (IL-1β), interleukin-18 (IL-18), and immunoregulatory-related factors interferon-γ (IFN-γ) were detected by ELISA. Furthermore, the expression of Toll-like receptor 4 (TLR4), p-IKKα/β, IKKα, IKKβ, p-IκBα, IκBα, p-NF-κB, nuclear factor-κB (NF-κB), NOD-like receptor family pyrin domain containing 3 (NLRP3), cleaved caspase-1, pro-caspase-1, apoptosis-associated speck-like protein containing CARD (ASC), and β-actin were tested by Western blot.Results: A total of 99 compounds were identified in QWZK, including 33 flavonoids, 23 phenolic acids, 3 alkaloids, 3 coumarins, 20 triterpenoids, 5 anthraquinones, and 12 others. ALI rats induced by LPS exhibited significant increase in neutrophile, significant decrease in lymphocyte, and evidently thicker alveolar wall than control animals. QWZK reversed the changes in WBC count and alveolar wall to normal level on the model of ALI induced by LPS. ELISA results revealed that QWZK significantly reduced the overexpression of proinflammatory factors IL-6, TNF-α, MCP-1, IL-1β, IL-18, and IFN-γ induced by LPS. Western blot results demonstrated that QWZK significantly downregulated the overexpression of TLR4, p-IKKα/β, p-IκBα, p-NF-κB, NLRP3, cleaved caspase-1, and ASC induced by LPS, which suggested that QWZK inhibited TLR4/NF-κB signaling pathway and NLRP3 inflammasomes.Conclusions: The chemical compositions of QWZK were first identified. It was demonstrated that QWZK showed protective effects on ALI induced by LPS. The possible underlying mechanisms of QWZK on ALI induced by LPS was via inhibiting TLR4/NF-kB signaling pathway and NLRP3 inflammasome activation. This work suggested that QWZK is a potential therapeutic candidate for the treatments of ALI and pulmonary inflammation.

scholarly journals Cichoric Acid Ameliorates Monosodium Urate-Induced Inflammatory Response by Reducing NLRP3 Inflammasome Activation via Inhibition of NF-kB Signaling Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Qi Wang ◽  
Bingfeng Lin ◽  
Zhifeng Li ◽  
Jie Su ◽  
Yulin Feng
Keyword(s):  
Inflammatory Response ◽  
Signaling Pathway ◽  
Nlrp3 Inflammasome ◽  
Gouty Arthritis ◽  
Inflammasome Activation ◽  
Cichoric Acid ◽  
Monosodium Urate ◽  
Protein Levels ◽  
Nlrp3 Inflammasome Activation ◽  
Tnf Α

Gouty arthritis is characterized by the deposition of monosodium urate (MSU) within synovial joints and tissues due to increased urate concentrations. Here, we elucidated the role of the natural compound cichoric acid (CA) on the MSU crystal-stimulated inflammatory response. The THP-1-derived macrophages (THP-Ms) were pretreated with CA and then stimulated with MSU suspensions. The protein levels of p65 and IκBα, the activation of the NF-κB signaling pathway by measuring the expression of its downstream inflammatory cytokines, and the activity of NLRP3 inflammasome were measured by western blotting and ELISA. CA treatment markedly inhibited the degradation of IκBα and the activation of NF-κB signaling pathway and reduced the levels of its downstream inflammatory genes such as IL-1β, TNF-α, COX-2, and PGE2 in the MSU-stimulated THP-M cells. Therefore, we infer that CA effectively alleviated MSU-induced inflammation by suppressing the degradation of IκBα, thereby reducing the activation of the NF-κB signaling pathway and the NLRP3 inflammasome. These results suggest that CA could be a novel therapeutic strategy in averting acute episodes of gout.

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 Distinct Molecular Mechanisms Underlying Potassium Efflux for NLRP3 Inflammasome Activation

2020 ◽  
Vol 11 ◽  
Author(s):  
Ziwei Xu ◽  
Zi-mo Chen ◽  
Xiaoyan Wu ◽  
Linjie Zhang ◽  
Ying Cao ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Inflammasome Activation ◽  
Potassium Efflux ◽  
Pannexin 1 ◽  
Nlrp3 Inflammasome Activation ◽  
K2p Channels ◽  
Pore Forming Proteins ◽  
Molecular Patterns

The NLRP3 inflammasome is a core component of innate immunity, and dysregulation of NLRP3 inflammasome involves developing autoimmune, metabolic, and neurodegenerative diseases. Potassium efflux has been reported to be essential for NLRP3 inflammasome activation by structurally diverse pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs). Thus, the molecular mechanisms underlying potassium efflux to activate NLRP3 inflammasome are under extensive investigation. Here, we review current knowledge about the distinction channels or pore-forming proteins underlying potassium efflux for NLRP3 inflammasome activation with canonical/non-canonical signaling or following caspase-8 induced pyroptosis. Ion channels and pore-forming proteins, including P2X7 receptor, Gasdermin D, pannexin-1, and K2P channels involved present viable therapeutic targets for NLRP3 inflammasome related diseases.

scholarly journals IIIM-941, a Stilbene Derivative Inhibits NLRP3 Inflammasome Activation by Inducing Autophagy

2021 ◽  
Vol 12 ◽  
Author(s):  
Mehboob Ali ◽  
Mehak Gupta ◽  
Abubakar Wani ◽  
Ankita Sharma ◽  
Mohd Abdullaha ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Inhibitory Activity ◽  
Inflammatory Diseases ◽  
Inflammasome Activation ◽  
Synthetic Compound ◽  
Nlrp3 Inflammasome Activation ◽  
Tnf Α ◽  
Pathological Development ◽  
Inflammasome Activity ◽  
Nlrp3 Activity

Aberrant activation of NLRP3 inflammasome has been implicated in several inflammatory diseases. Autophagy is one of the primary mechanisms that regulate NLRP3 inflammasome activity. In this study, we attempted to target NLRP3 inflammasome activity by a synthetic compound IIIM-941. We found that IIIM-941 inhibits ATP induced NLRP3 inflammasome by induction of autophagy through AMPK pathway in bone marrow derived macrophages (BMDMs) and J774A.1 cells. It was interesting to observe that IIIM-941 did not show any inhibitory activity against LPS induced pro-inflammatory cytokines TNF-α and IL-6. The anti-NLRP3 activity of IIIM-941 was significantly reversed when we attempted to block autophagy by using either pharmacological inhibitor bafilomycin A1or by using siRNA against AMPK. Further, we found that IIIM-941 downregulated the expression of NLRP3 and prevented the oligomerization of ASC to exert its anti-NLRP3 inflammasome effect in J774A.1 cells. We validated inhibitory activity of IIIM-941 against NLRP3 in three different mice models. The anti-inflammatory effect of IIIM-941 was highly significant in ATP induced peritoneal inflammation model. IIIM-941 was similarly effective in suppressing MSU induced IL-1β in the air pouch model of inflammation without affecting the levels of TNF-α and IL-6. Finally, oral efficacy of IIIM-941 was also proved in MSU indued foot paw edema model of inflammation in mice at 10 and 20 mg/kg (b.w.). The compounds like IIIM-941 can be explored further for the development of therapies against diseases such as Alzheimer’s disease and Parkinson’s disease, where hampered autophagy and NLRP3 activation play a crucial role in the pathological development.

scholarly journals Orientin Ameliorates LPS-Induced Inflammatory Responses through the Inhibitory of the NF-κB Pathway and NLRP3 Inflammasome

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Qingfei Xiao ◽  
Zhihui Qu ◽  
Ying Zhao ◽  
Liming Yang ◽  
Pujun Gao
Keyword(s):  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Receptor Protein ◽  
Raw 264.7 Cells ◽  
Prostaglandin E ◽  
Inflammasome Activation ◽  
Therapeutic Effects ◽  
Protective Effects ◽  
Nlrp3 Inflammasome Activation ◽  
Underlying Mechanisms

Inflammation is a complex response to diverse pathological conditions, resulting in negative rather than protective effects when uncontrolled. Orientin (Ori), a flavonoid component isolated from natural plants, possesses abundant properties. Thus, we aimed to discover the potential therapeutic effects of orientin on lipopolysaccharide- (LPS-) induced inflammation in RAW 264.7 cells and the underlying mechanisms. In our studies, we evaluated the effects of Ori on proinflammatory mediator production stimulated by LPS, including tumor necrosis factor- (TNF-) α, interleukin- (IL-) 6, IL-18, and IL-1β, along with prostaglandin E2 (PGE2) and NO. Our data indicated that orientin dramatically inhibited the levels of these mediators. Consistent with these results, the expression levels of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) were also reduced. Further study demonstrated that such inhibitory effects of Ori were due to suppression of the nuclear factor-kappa B (NF-κB) pathway and nucleotide-binding domain- (NOD-) like receptor protein 3 (NLRP3) inflammasome activation, which may contribute to its anti-inflammatory effects. Together, these findings show that Ori may be an effective candidate for ameliorating LPS-induced inflammatory responses.

scholarly journals Inhibition of oxidative stress and NLRP3 inflammasome by Saikosaponin-d alleviates acute liver injury in carbon tetrachloride-induced hepatitis in mice

2020 ◽  
Vol 34 ◽  
pp. 205873842095059
Author(s):  
Yirong Chen ◽  
Renye Que ◽  
Liubing Lin ◽  
Yanting Shen ◽  
Jinkai Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Carbon Tetrachloride ◽  
Liver Injury ◽  
Nlrp3 Inflammasome ◽  
Acute Liver Injury ◽  
Inflammasome Activation ◽  
Protective Effects ◽  
Mice Model ◽  
Caspase 1 ◽  
Nlrp3 Inflammasome Activation

NLRP3 inflammasome activation results in severe liver inflammation and injury. Saikosaponin-d (SSd) possesses anti-inflammatory and hepatoprotective effects. This study aimed to determine the protective effects of SSd on carbon tetrachloride (CCl4)-induced acute liver injury in mice, and whether oxidative stress and NLRP3 inflammasome activation participate in the process. The CCl4 mice model and controls were induced. The mice were treated with SSd at 1, 1.5, or 2.0 mg/kg in a total volume of 100 µl/25 g of body weight. Liver injury was assessed by histopathology. Oxidative stress was determined using mitochondrial superoxide production (MSP), malondialdehyde (MDA) content, and superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities. NLRP3, ASC, and Caspase 1 were determined by real-time PCR and western blot. IL-1β and IL-18 levels were determined by ELISA. Significantly elevated oxidative stress was induced in the liver by CCl4, as demonstrated by histopathology and increases of MDA and MSP levels and decreases of SOD, GPx, and CAT activities (all P < 0.01). SSd significantly decreased the MDA and MSP levels and increased the activities of SOD, GPx, and CAT (all P < 0.05). The mRNA expression of NLRP3, ASC, and Caspase 1, and the protein expression of Caspase 1-p10, NLRP3, ASC, IL-1β, and IL-18 were significantly increased after CCl4 induction (all P < 0.01). These changes were reversed by SSd (all P < 0.05). Suppression of the oxidative stress and NLRP3 inflammasome activation were involved in SSd-alleviated acute liver injury in CCl4-induced hepatitis.

scholarly journals NLRP3 Inflammasome Modulation by Melatonin Supplementation in Chronic Pristane-Induced Lupus Nephritis

2019 ◽  
Vol 20 (14) ◽  
pp. 3466 ◽  
Author(s):  
Francesca Bonomini ◽  
Mariane Dos Santos ◽  
Francisco Veríssimo Veronese ◽  
Rita Rezzani
Keyword(s):  
Oxidative Stress ◽  
Lupus Nephritis ◽  
Lupus Erythematosus ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Morphological Alteration ◽  
Inflammasome Activation ◽  
Protective Effects ◽  
Nlrp3 Inflammasome Activation

Lupus nephritis (LN) is a kidney inflammatory disease caused by systemic lupus erythematosus (SLE). NLRP3 inflammasome activation is implicated in LN pathogenesis, suggesting its potential targets for LN treatment. Melatonin, an endogenous indoleamine, is considered an important multitasking molecule that has been reported to have anti-inflammatory effects by inhibiting nuclear factor-kappa B (NF-κB)-mediated inflammatory responses in vivo. This molecule has also protective effects against the activation of the inflammasomes and, in particular, the NLRP3 inflammasome. Thus, this work evaluated the effect of melatonin on morphological alteration and NLRP3 inflammasome activation in LN pristane mouse models. To evaluate the melatonin effects in these mice, we studied the renal cytoarchitecture by means of morphological analyses and immunohistochemical expression of specific markers related to oxidative stress, inflammation and inflammasome activation. Our results showed that melatonin attenuates pristane-induced LN through restoring of morphology and attenuation of oxidative stress and inflammation through a pathway that inhibited activation of NLRP3 inflammasome signaling. Our data clearly demonstrate that melatonin has protective activity on lupus nephritis in these mice that is highly associated with its effect on enhancing the Nrf2 antioxidant signaling pathway and decreasing renal NLRP3 inflammasome activation.

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