Muscone relieves inflammatory pain by inhibiting microglial activation-mediated inflammatory response via abrogation of the NOX4/JAK2-STAT3 pathway and NLRP3 inflammasome

2020 ◽  
Vol 82 ◽  
pp. 106355 ◽  
Author(s):  
Shanshan Yu ◽  
Guoqing Zhao ◽  
Fanglei Han ◽  
Wenzhao Liang ◽  
Yuan Jiao ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Pain ◽  
Microglial Activation ◽  
Stat3 Pathway

scholarly journals Enhancement of LPS-Induced Microglial Inflammation Response via TLR4 Under High Glucose Conditions

2015 ◽  
Vol 35 (4) ◽  
pp. 1571-1581 ◽  
Author(s):  
Xiang Zhang ◽  
Hongquan Dong ◽  
Susu Zhang ◽  
Shunmei Lu ◽  
Jie Sun ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Signaling Pathways ◽  
High Glucose ◽  
Microglial Activation ◽  
Postoperative Cognitive Dysfunction ◽  
Toll Like Receptor 4 ◽  
Stat3 Pathway ◽  
Cytokine Levels ◽  
Normal Glucose ◽  
Microglial Inflammation

Background: Microglia activation mediated by toll-like receptor 4 (TLR4) plays an important role in neuroinflammation and postoperative cognitive dysfunction (POCD). Diabetes mellitus (DM) has been recently suggested as an independent risk factor for POCD. In this study, we investigate the potential exacerbation of the inflammatory response in primary microglia due to high glucose conditions. Methods: Primary microglial cells were exposed to normal glucose (25 mmol/L) and high glucose (35 mmol/L) levels alone or with lipopolyscaccharide (LPS 0, 2, 5, 10 ng/mL). The pro-inflammatory response of the cells was assessed by measuring changes in cytokine levels and the evaluation of associated signaling pathways. Results: Neither high glucose nor low LPS (≤5ng/ml) alone had an effect on TNF-a and IL-6 levels, but the combination of low LPS and high glucose stimulated the inflammatory response. Analyses of the associated signaling pathways demonstrated that high glucose enhanced the LPS-induced microglial activation via the TLR4/JAK2/STAT3 pathway. Conclusion: This study demonstrates that high glucose, one of the key abnormalities characteristic of DM, can augment LPS-induced microglial activation and inflammatory cytokine levels through the TLR4/JAK2/STAT3 pathway, offering new insight into the pathophysiological relationship between DM and POCD.

Glycyrrhizin ameliorates inflammatory pain by inhibiting microglial activation-mediated inflammatory response via blockage of the HMGB1-TLR4-NF-kB pathway

2018 ◽  
Vol 369 (1) ◽  
pp. 112-119 ◽  
Author(s):  
Xiaojuan Sun ◽  
Hongyou Zeng ◽  
Qingsong Wang ◽  
Qingwen Yu ◽  
Jianxiong Wu ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Inflammatory Pain ◽  
Microglial Activation

scholarly journals Lipopolysaccharide induces neuroinflammation in microglia by activating the MTOR pathway and downregulating Vps34 to inhibit autophagosome formation

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Xiaoxia Ye ◽  
Mingming Zhu ◽  
Xiaohang Che ◽  
Huiyang Wang ◽  
Xing-Jie Liang ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Microglial Activation ◽  
Adaptor Protein ◽  
Mtor Pathway ◽  
Microglial Cells ◽  
Inflammatory Factors ◽  
Intraventricular Injection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Autophagic Flux

Abstract Background Microglial activation is a prominent feature of neuroinflammation, which is present in almost all neurodegenerative diseases. While an initial inflammatory response mediated by microglia is considered to be protective, excessive pro-inflammatory response of microglia contributes to the pathogenesis of neurodegeneration. Although autophagy is involved in the suppression of inflammation, its role and mechanism in microglia are unclear. Methods In the present study, we studied the mechanism by which lipopolysaccharide (LPS) affects microglial autophagy and the effects of autophagy on the production of pro-inflammatory factors in microglial cells by western blotting, immunocytochemistry, transfection, transmission electron microscopy (TEM), and real-time PCR. In a mouse model of neuroinflammation, generated by intraventricular injection of LPS (5 μg/animal), we induced autophagy by rapamycin injection and investigated the effects of enhanced autophagy on microglial activation by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry. Results We found that autophagic flux was suppressed in LPS-stimulated N9 microglial cells, as evidenced by decreased expression of the autophagy marker LC3-II (lipidated form of MAP1LC3), as well as increased levels of the autophagy adaptor protein SQSTM1. LPS significantly decreased Vps34 expression in N9 microglial cells by activating the PI3KI/AKT/MTOR pathway without affecting the levels of lysosome-associated proteins and enzymes. More importantly, overexpression of Vps34 significantly enhanced the autophagic flux and decreased the accumulation of SQSTM1 in LPS-stimulated N9 microglial cells. Moreover, our results revealed that an LPS-induced reduction in the level of Vps34 prevented the maturation of omegasomes to phagophores. Furthermore, LPS-induced neuroinflammation was significantly ameliorated by treatment with the autophagy inducer rapamycin both in vitro and in vivo. Conclusions These data reveal that LPS-induced neuroinflammation in N9 microglial cells is associated with the inhibition of autophagic flux through the activation of the PI3KI/AKT/MTOR pathway, while enhanced microglial autophagy downregulates LPS-induced neuroinflammation. Thus, this study suggests that promoting the early stages of autophagy might be a potential therapeutic approach for neuroinflammation-associated diseases.

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 Janus Kinase Inhibition Ameliorates Ischemic Stroke Injury and Neuroinflammation Through Reducing NLRP3 Inflammasome Activation via JAK2/STAT3 Pathway Inhibition

2021 ◽  
Vol 12 ◽  
Author(s):  
Hua Zhu ◽  
Zhihong Jian ◽  
Yi Zhong ◽  
Yingze Ye ◽  
Yonggang Zhang ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Brain Tissue ◽  
Proinflammatory Cytokines ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Immunofluorescence Staining ◽  
Western Blots ◽  
Stat3 Pathway ◽  
Stat3 Signaling

BackgroundInflammatory responses play a multiphase role in the pathogenesis of cerebral ischemic stroke (IS). Ruxolitinib (Rux), a selective oral JAK 1/2 inhibitor, reduces inflammatory responses via the JAK2/STAT3 pathway. Based on its anti-inflammatory and immunosuppressive effects, we hypothesized that it may have a protective effect against stroke. The aim of this study was to investigate whether inhibition of JAK2 has a neuroprotective effect on ischemic stroke and to explore the potential molecular mechanisms.MethodsRux, MCC950 or vehicle was applied to middle cerebral artery occlusion (MCAO) mice in vivo and an oxygen-glucose deprivation/reoxygenation (OGD/R) model in vitro. After 3 days of reperfusion, neurological deficit scores, infarct volume and brain water content were assessed. Immunofluorescence staining and western blots were used to measure the expression of NLRP3 inflammasome components. The infiltrating cells were investigated by flow cytometry. Proinflammatory cytokines were assessed by RT-qPCR. The expression of the JAK2/STAT3 pathway was measured by western blots. Local STAT3 deficiency in brain tissue was established with a lentiviral vector carrying STAT3 shRNA, and chromatin immunoprecipitation (ChIP) assays were used to investigate the interplay between NLRP3 and STAT3 signaling.ResultsRux treatment improved neurological scores, decreased the infarct size and ameliorated cerebral edema 3 days after stroke. In addition, immunofluorescence staining and western blots showed that Rux application inhibited the expression of proteins related to the NLRP3 inflammasome and phosphorylated STAT3 (P-STAT3) in neurons and microglia/macrophages. Furthermore, Rux administration inhibited the expression of proinflammatory cytokines, including TNF-α, IFN-γ, HMGB1, IL-1β, IL-2, and IL-6, suggesting that Rux may alleviate IS injury by inhibiting proinflammatory reactions via JAK2/STAT3 signaling pathway regulation. Infiltrating macrophages, B, T, cells were also reduced by Rux. Local STAT3 deficiency in brain tissue decreased histone H3 and H4 acetylation on the NLRP3 promoter and NLRP3 inflammasome component expression, indicating that the NLRP3 inflammasome may be directly regulated by STAT3 signaling. Rux application suppressed lipopolysaccharide (LPS)-induced NLRP3 inflammasome secretion and JAK2/STAT3 pathway activation in the OGD/R model in vitro.ConclusionJAK2 inhibition by Rux in MCAO mice decreased STAT3 phosphorylation, thus inhibiting the expression of downstream proinflammatory cytokines and the acetylation of histones H3 and H4 on the NLRP3 promoter, resulting in the downregulation of NLRP3 inflammasome expression.

scholarly journals ANXA3 regulates HIF1α-induced NLRP3 inflammasome activity and promotes LPS-induced inflammatory response in bronchial epithelial cells

2021 ◽  
Keyword(s):  
Epithelial Cells ◽  
Inflammatory Response ◽  
Nlrp3 Inflammasome ◽  
Hypoxia Inducible Factor ◽  
Bronchial Epithelial Cells ◽  
Inflammasome Activation ◽  
Bronchial Epithelial ◽  
Asthmatic Patients ◽  
Pediatric Diseases ◽  
Inflammasome Activity

Introduction: Childhood asthma is one of the most common pediatric diseases, and its incidence is increasing. Annexin A3 (ANXA3) is a member of the Annexin family, a well-known polygenic family of membrane binding proteins. Bioinformation analysis showed that ANXA3 was highly expressed in asthmatic patients, suggesting the effects of ANXA3 on asthma, whereas the mechanism is still unclear. Methods: A inflammatory response model of bronchial epithelial BEAS-2B cells induced by LPS was constructed. Immunoblot and quantitative PCR assays were performed to detect the expression levels of ANXA3 in control or LPS-induced BEAS-2B cells. MTT, flow cytometry (FCM), and Immunoblot assays were respectively conducted to detect the effects of ANXA3 on survival and apoptosis of LPS-induced BEAS-2B cells. qPCR and ELISA assays were performed to detect the expression of TNF-α, IL-6, and IL-8. Additionally, Immunoblot assays were performed to detect the effects of ANXA3 on HIF1α and NLRP3 inflammasome in BEAS-2B cells. Results: We found ANXA3 was overexpressed in LPS-induced BEAS-2B cells. ANXA3 ablation promoted the survival of LPS-induced BEAS-2B cells and suppressed the inflammatory response of LPS-induced BEAS-2B cells. Importantly, we noticed ANXA3 inhibited HIF1α-induced NLRP3 inflammasome activity, and increasing the expression of HIF-α rescued the effects of ANXA3 depletion on asthma. Conclusion: ANXA3 enhanced LPS-triggered inflammation of human bronchial epithelial cells by regulating hypoxia-inducible factor-1α (HIF1α)-mediated NLRP3 inflammasome activation, and thought ANXA3 as a promising molecular target for acute asthma treatment.

mTOR inhibition as a possible pharmacological target in the management of systemic inflammatory response and associated neuroinflammation by lipopolysaccharide challenge in rats

2021 ◽  
Author(s):  
Demet Sinem Guden ◽  
Meryem Temiz-Resitoglu ◽  
Sefika Pınar Senol ◽  
Deniz Kibar ◽  
Sakir Necat Yilmaz ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Microglial Activation ◽  
Critical Role ◽  
Mammalian Target Of Rapamycin ◽  
Hypoxia Inducible Factor ◽  
B Cell Lymphoma ◽  
Nuclear Factor Κb ◽  
Systemic Inflammatory Response ◽  
Mtor Inhibition ◽  
Factor Α

Neuroinflammation plays a critical role during sepsis triggered by microglial activation. Mammalian target of rapamycin (mTOR) has gained attraction in neuroinflammation, however, the mechanism remains unclear. Our goal was to assess the effects of mTOR inhibition by rapamycin on inflammation, microglial activation, oxidative stress, and apoptosis associated with the changes in the inhibitor-κB (IκB)-α/nuclear factor-κB (NF-κB)/hypoxia-inducible factor-1α (HIF-1α) pathway activity following a systemic challenge with lipopolysaccharide (LPS). Rats received saline (10 ml/kg), LPS (10 mg/kg), and/or rapamycin (1 mg/kg) via intraperitoneally. Inhibition of mTOR by rapamycin blocked phosphorylated form of ribosomal protein S6, NF-κB p65 activity by increasing degradation of IκB-α in parallel with HIF-1α expression increased by LPS in the kidney, heart, lung, and brain tissues. Rapamycin attenuated the increment in the expression of tumor necrosis factor-α and interleukin-1β, the inducible nitric oxide synthase, gp91<sup>phox</sup>, and p47<sup>phox</sup> in addition to nitrite levels elicited by LPS in tissues or sera. Concomitantly, rapamycin treatment reduced microglial activation, brain expression of caspase-3, and Bcl-2-associated X protein while increased expression of B-cell lymphoma 2 induced by LPS. Overall, this study supports the hypothesis that mTOR contributes to the detrimental effect of LPS-induced systemic inflammatory response associated with neuroinflammation via IκB-α/NF-κB/HIF-1α signaling pathway.

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