scholarly journals The gut microbial metabolite trimethylamine N-oxide aggravates GVHD by inducing M1 macrophage polarization in mice

Blood ◽  
2020 ◽  
Vol 136 (4) ◽  
pp. 501-515 ◽  
Author(s):  
Kunpeng Wu ◽  
Yan Yuan ◽  
Huihui Yu ◽  
Xin Dai ◽  
Shu Wang ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Macrophage Polarization ◽  
Short Chain Fatty Acids ◽  
Inflammasome Activation ◽  
Microbial Metabolites ◽  
M1 Macrophage ◽  
The Impact

Abstract The diversity of the human microbiome heralds the difference of the impact that gut microbial metabolites exert on allogenic graft-versus-host (GVH) disease (GVHD), even though short-chain fatty acids and indole were demonstrated to reduce its severity. In this study, we dissected the role of choline-metabolized trimethylamine N-oxide (TMAO) in the GVHD process. Either TMAO or a high-choline diet enhanced the allogenic GVH reaction, whereas the analog of choline, 3,3-dimethyl-1-butanol reversed TMAO-induced GVHD severity. Interestingly, TMAO-induced alloreactive T-cell proliferation and differentiation into T-helper (Th) subtypes was seen in GVHD mice but not in in vitro cultures. We thus investigated the role of macrophage polarization, which was absent from the in vitro culture system. F4/80+CD11b+CD16/32+ M1 macrophage and signature genes, IL-1β, IL-6, TNF-α, CXCL9, and CXCL10, were increased in TMAO-induced GVHD tissues and in TMAO-cultured bone marrow–derived macrophages (BMDMs). Inhibition of the NLRP3 inflammasome reversed TMAO-stimulated M1 features, indicating that NLRP3 is the key proteolytic activator involved in the macrophage’s response to TMAO stimulation. Consistently, mitochondrial reactive oxygen species and enhanced NF-κB nuclear relocalization were investigated in TMAO-stimulated BMDMs. In vivo depletion of NLRP3 in GVHD recipients not only blocked M1 polarization but also reversed GVHD severity in the presence of TMAO treatment. In conclusion, our data revealed that TMAO-induced GVHD progression resulted from Th1 and Th17 differentiation, which is mediated by the polarized M1 macrophage requiring NLRP3 inflammasome activation. It provides the link among the host choline diet, microbial metabolites, and GVH reaction, shedding light on alleviating GVHD by controlling choline intake.

Kaempferol Alleviates Corneal Transplantation Rejection by Inhibiting NLRP3 Inflammasome Activation and Macrophage M1 Polarization via Promoting Autophagy

2021 ◽  
Author(s):  
Huiwen Tian ◽  
Shumei Lin ◽  
Jing Wu ◽  
Ming Ma ◽  
Jian Yu ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Macrophage Polarization ◽  
Corneal Transplantation ◽  
Inflammasome Activation ◽  
M1 Polarization ◽  
Nlrp3 Inflammasome Activation ◽  
M1 Macrophage ◽  
Transplantation Rejection

Abstract Corneal transplantation rejection remains a major threat to the success rate in high-risk patients. Given the many side effects presented by traditional immunosuppressants, there is an urgency to clarify the mechanism of corneal transplantation rejection and to identify new therapeutic targets. Kaempferol is a natural flavonoid that has been proven in various studies to possess anti-inflammatory, antioxidant, anticancer, and neuroprotective properties. However, the relationship between kaempferol and corneal transplantation remains largely unexplored. To address this, both in vivo and in vitro, we established a model of corneal allograft transplantation in Wistar rats and an LPS-induced inflammatory model in THP-1 derived human macrophages. In the transplantation experiments, we observed an enhancement in the NLRP3 / IL-1 β axis and in M1 macrophage polarization post-operation. In groups to which kaempferol intraperitoneal injections were administered, this response was effectively reduced. However, the effect of kaempferol was reversed after the application of autophagy inhibitors. Similarly, in the inflammatory model, we found that different concentrations of kaempferol can reduce the LPS-induced M1 polarization and NLRP3 inflammasome activation. Moreover, we confirmed that kaempferol induced autophagy and that autophagy inhibitors reversed the effect in macrophages. In conclusion, we found that kaempferol can inhibit the activation of the NLRP3 inflammasomes by inducing autophagy, thus inhibiting macrophage polarization, and ultimately alleviating corneal transplantation rejection. Thus, our study suggests that kaempferol could be used as a potential therapeutic agent in the treatment of allograft rejection.

scholarly journals Histone lactylation drives oncogenesis by facilitating m6A reader protein YTHDF2 expression in ocular melanoma

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jie Yu ◽  
Peiwei Chai ◽  
Minyue Xie ◽  
Shengfang Ge ◽  
Jing Ruan ◽  
...  
Keyword(s):  
Macrophage Polarization ◽  
Regulation Of Gene Expression ◽  
Metabolic Stress ◽  
Ocular Melanoma ◽  
Rna Modifications ◽  
M1 Macrophage ◽  
Melanoma Therapy

Abstract Background Histone lactylation, a metabolic stress-related histone modification, plays an important role in the regulation of gene expression during M1 macrophage polarization. However, the role of histone lactylation in tumorigenesis remains unclear. Results Here, we show histone lactylation is elevated in tumors and is associated with poor prognosis of ocular melanoma. Target correction of aberrant histone lactylation triggers therapeutic efficacy both in vitro and in vivo. Mechanistically, histone lactylation contributes to tumorigenesis by facilitating YTHDF2 expression. Moreover, YTHDF2 recognizes the m6A modified PER1 and TP53 mRNAs and promotes their degradation, which accelerates tumorigenesis of ocular melanoma. Conclusion We reveal the oncogenic role of histone lactylation, thereby providing novel therapeutic targets for ocular melanoma therapy. We also bridge histone modifications with RNA modifications, which provides novel understanding of epigenetic regulation in tumorigenesis.

scholarly journals Inhibitory Role of Berberine, an Isoquinoline Alkaloid, on NLRP3 Inflammasome Activation for the Treatment of Inflammatory Diseases

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6238
Author(s):  
Paromita Sarbadhikary ◽  
Blassan P. George ◽  
Heidi Abrahamse
Keyword(s):  
Nlrp3 Inflammasome ◽  
Inflammatory Diseases ◽  
In Vivo Studies ◽  
Inflammasome Activation ◽  
Inflammatory Disorders ◽  
Nlrp3 Inflammasome Activation ◽  
Anti Inflammatory

The pyrin domain-containing multiprotein complex NLRP3 inflammasome, consisting of the NLRP3 protein, ASC adaptor, and procaspase-1, plays a vital role in the pathophysiology of several inflammatory disorders, including neurological and metabolic disorders, chronic inflammatory diseases, and cancer. Several phytochemicals act as promising anti-inflammatory agents and are usually regarded to have potential applications as complementary or alternative therapeutic agents against chronic inflammatory disorders. Various in vitro and in vivo studies have reported the anti-inflammatory role of berberine (BRB), an organic heteropentacyclic phytochemical and natural isoquinoline, in inhibiting NLRP3 inflammasome-dependent inflammation against many disorders. This review summarizes the mechanism and regulation of NLRP3 inflammasome activation and its involvement in inflammatory diseases, and discusses the current scientific evidence on the repressive role of BRB on NLRP3 inflammasome pathways along with the possible mechanism(s) and their potential in counteracting various inflammatory diseases.

CLEC5A knockdown protects against the cardiac dysfunction after Myocardial infarction by suppressing macrophage polarization, NLRP3 inflammasome activation and pyroptosis

2021 ◽  
Author(s):  
Xin Wang ◽  
Yu Hu ◽  
Yaguang Wang ◽  
Dapeng Shen ◽  
Guizhou Tao
Keyword(s):  
Myocardial Infarction ◽  
Nlrp3 Inflammasome ◽  
Cardiac Dysfunction ◽  
Macrophage Polarization ◽  
Left Ventricular ◽  
Receptor Protein ◽  
Inflammasome Activation ◽  
M1 Polarization

Increasing evidence has shown that NOD-like receptor protein 3 (NLRP3) inflammasome and pyroptotic cell death play vital roles in the pathophysiology of myocardial infarction (MI), a common cardiovascular disease characterized with cardiac dysfunction. C-type lectin member 5A (CLEC5A) is reported to strongly associate with activation of NLRP3 inflammasome and pyroptosis. In this study, in vivo MI model was established by the ligation of left anterior descending coronary artery on male C57BL/6 mice, and CLEC5A knockdown was further achieved by intra-myocardial injection of adenovirus delivering shRNA-CLEC5A. CLEC5A was found to be highly expressed in left ventricular of MI mice, while CLEC5A knockdown conversely alleviated the cardiac dysfunction in MI mice. Besides, MI-induced classical activation of macrophages was significantly inhibited after CLEC5A silencing. Additionally, CLEC5A knockdown dramatically inhibited MI-triggered activation of NLRP3 inflammasome, pyroptosis and NF-κB signaling in left ventricular of mice. In vitro experiment further validated that CLEC5A knockdown suppressed M1 polarization in LPS/IFNγ-stimulated RAW264.7 cells, and inhibited the polarized RAW264.7-induced activation of NLRP3 inflammasome/pyroptosis signaling in co-cultured cardiomyocytes. In conclusion, CLEC5A knockdown protects against the MI-induced cardiac dysfunction by regulating macrophage polarization, NLRP3 inflammasome and cell pyroptosis.

scholarly journals Atractylenolide I Inhibits NLRP3 Inflammasome Activation in Colitis-Associated Colorectal Cancer via Suppressing Drp1-Mediated Mitochondrial Fission

2021 ◽  
Vol 12 ◽  
Author(s):  
Yao Qin ◽  
Yanwei Yu ◽  
Chendong Yang ◽  
Zhuien Wang ◽  
Yi Yang ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Nlrp3 Inflammasome ◽  
Lentiviral Vector ◽  
Mitochondrial Fission ◽  
Inflammasome Activation ◽  
Atractylenolide I ◽  
Nlrp3 Inflammasome Activation

Inflammatory bowel disease (IBD) is an important high-risk factor that promotes the occurrence and development of colon cancer. Research on the mechanism of regulating NLRP3 can provide potential targets for treating NLRP3 inflammasome–related diseases and changing the inflammatory potential of immune cells. In this study, the effects of atractylenolide I on colitis-associated CRC (caCRC) and inflammasome activation were investigated both in vivo and in vitro. Furthermore, the role of atractylenolide I on Drp1-mediated mitochondrial fission was analyzed via Western blotting and transmission electron microscopy (TEM). Moreover, the Drp1 overexpression lentiviral vector was used to study the role of Drp1 on the signaling mechanisms of atractylenolide I. Atractylenolide I treatment significantly reduced the cell viability of human HCT116 and SW480 cells and induced apoptosis, and effectively inhibited colon tumors in the AOM/DSS mouse model. The reduction of NLRP3 inflammasome activation and excessive fission of mitochondria mediated by Drp1 were associated with the administration of atractylenolide I. Upregulation of Drp1 reversed the inhibitory effect of atractylenolide I on the activation of NLRP3 inflammasomes. Overexpressing the Drp1 expression counteracted the restraint of atractylenolide I on the release of IL-1β of LPS/DSS-stimulated BMDMs. Atractylenolide I inhibited NLRP3 and caspase-1 expression in mice BMDMs, with no influence in the Drp1-overexpressed BMDMs. These results demonstrated that atractylenolide I inhibits NLRP3 inflammasome activation in colitis-associated colorectal cancer via suppressing Drp1-mediated mitochondrial fission.

scholarly journals Melatonin Alleviates Microglia-Mediated Neuroinflammation By Suppressing NLRP3 Inflammasome-Mediated Pyroptosis Via ROS/mtDNA/STING Pathway After Spinal Cord Injury

2021 ◽  
Author(s):  
Jin Wang ◽  
Haiyuan Yang ◽  
Fan Zhang ◽  
Minghao Shao ◽  
Haocheng Xu ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Nlrp3 Inflammasome Activation ◽  
Cord Injury ◽  
Sting Pathway

Abstract BackgroundMicroglia pyroptosis-induced neuroinflammation has been one of the potential treatment targets for spinal cord injury (SCI). And melatonin is reported to have anti-neuroinflammation effect on SCI, but the underlying mechanism is largely unexplored. In addition, the potential regulatory role of stimulator of interferon genes (STING) mediated innate immune response in the SCI-induced neuroinflammation also remains unknown. The aim of this study is to identify the potential molecular mechanism of the anti-neuroinflammation effect of melatonin in SCI mice and to explore whether STING-mediated signal pathway is involved in this pharmacological process. MethodsIn vivo, the C57BL/6 female mice underwent SCI injury or Sham surgery (laminectomy alone). Melatonin and selective STING antagonist C-176 were administered intraperitoneally after injury in the SCI group once a day for 3 or 28 consecutive days for different experiments. The BMS score system was adopted to assess the motor function of mice. In vitro, the Lipopolysaccharide (LPS)/ATP was combinedly used to induce cell pyroptosis in BV2 microglia and the adenovirus was used to overexpress STING. A series of molecular experiments including Western blot (WB), quantitative real-time polymerase chain reaction (RT-qPCR), enzyme linked immunosorbent assay (ELISA) and immunofluorescence (IF) were performed in vivo and in vitro. ResultsOur results showed that melatonin effectively suppressed NLRP3 inflammasome-induced pyroptosis and STING-mediated pathway after SCI. In addition, C-176 also alleviated the NLRP3 inflammasome-mediated pyroptosis and promoted functional recovery in vivo. In vitro, we also found that melatonin abrogated NLRP3 inflammasome activation in LPS/ATP-induced BV2 cells, while overexpression of STING reversed the anti-pyroptotic role of melatonin. Subsequent results together indicated that the role of melatonin on STING-dependent NLRP3 inflammasome activation may be mediated by decreasing ROS production and cytosolic mtDNA release. ConclusionThis study preliminarily demonstrated that melatonin exerts its anti-neuroinflammation role on SCI by alleviating the NLRP3 inflammasome-mediated pyroptosis, which was mediated by blocking the ROS/mtDNA/STING pathway. It provides us a better understanding of the pathological mechanism after SCI and offer experiment evidence to promote the use of melatonin for SCI.

The role of NLRP3 inflammasome activation in the neuroinflammatory responses to Ag2Se quantum dots in microglia

Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20820-20836 ◽  
Author(s):  
Tianshu Wu ◽  
Xue Liang ◽  
Keyu He ◽  
Tingting Wei ◽  
Yan Wang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Cytokine ◽  
Inflammasome Activation ◽  
Activated Microglia ◽  
Nlrp3 Inflammasome Activation

Ag2Se QD exposure activated microglia followed by pro-inflammatory cytokine IL-1β release in vivo and in vitro through NLRP3 inflammasome activation.

Microcystin-LR Induces NLRP3 Inflammasome Activation via FOXO1 Phosphorylation, Resulting in Interleukin-1β Secretion and Pyroptosis in Hepatocytes

2020 ◽  
Author(s):  
Yali Zhang ◽  
Peipei Zhu ◽  
Xiaofeng Wu ◽  
Tianli Yuan ◽  
Zhangyao Su ◽  
...  
Keyword(s):  
Nlrp3 Inflammasome ◽  
Interleukin 1Β ◽  
Inflammasome Activation ◽  
Inflammatory Injury ◽  
Nlrp3 Inflammasome Activation ◽  
Phosphatase 2A ◽  
Related Proteins

Abstract Microcystin-LR (MC-LR), the most common and toxic microcystin (MC) present in freshwater, poses a substantial threat to human health, especially hepatotoxicity. Recent evidence reveals that the NLRP3 inflammasome plays an important role in liver injury by activating caspase-1 to promote interleukin-1β (IL-1β) secretion. In this study, we investigated the possible role of NLRP3 inflammasome activation in MC-LR-induced mouse liver inflammatory injury. We found that MC-LR administered to mice by oral gavage mainly accumulated in liver and induced the activation of the NLRP3 inflammasome and production of mature IL-1β. Additionally, we observed an increase in the levels of NLRP3 inflammasome-related proteins and the proportion of pyroptosis in MC-LR-treated AML-12 cells. We also found that inhibition of NLRP3 in mice attenuated MC-LR-induced IL-1β production, indicating an essential role for NLRP3 in MC-LR-induced liver inflammatory injury. In addition, we found that inhibition of FOXO1 by AKT-mediated hyperphosphorylation, due to protein phosphatase 2A (PP2A) inhibition, is required for MC-LR-induced expression of NLRP3. Taken together, our in vivo and in vitro findings suggest a model in which the NLRP3 inflammasome activation, a result of AKT-mediated hyperphosphorylation of FOXO1 through inhibition of PP2A, plays a key role in MC-LR–induced liver inflammatory injury via IL-1β secretion and pyroptotic cell death.

scholarly journals NLRP3 inflammasome activation in aged macrophages is diminished during Streptococcus pneumoniae infection

2018 ◽  
Vol 314 (3) ◽  
pp. L372-L387 ◽  
Author(s):  
Soo Jung Cho ◽  
Kristen Rooney ◽  
Augustine M. K. Choi ◽  
Heather W. Stout-Delgado
Keyword(s):  
Streptococcus Pneumoniae ◽  
Nlrp3 Inflammasome ◽  
The United States ◽  
Biological Aging ◽  
Inflammasome Activation ◽  
Pneumococcal Infections ◽  
Nlrp3 Inflammasome Activation ◽  
The Impact

Pneumococcal infections are the eigth leading cause of death in the United States, and it is estimated that older patients (≥65 yr of age) account for the most serious cases. The goal of our current study is to understand the impact of biological aging on innate immune responses to Streptococcus pneumoniae, a causative agent of bacterial pneumonia. With the use of in vitro and in vivo aged murine models, our findings demonstrate that age-enhanced unfolded protein responses (UPRs) contribute to diminished inflammasome assembly and activation during S. pneumoniae infection. Pretreatment of aged mice with endoplasmic reticulum chaperone and the stress-reducing agent tauroursodeoxycholic acid (TUDCA) decreased mortality in aged hosts that was associated with increased NLRP3 inflammasome activation, improved pathogen clearance, and decreased pneumonitis during infection. Taken together, our data provide new evidence as to why older persons are more susceptible to S. pneumoniae and provide a possible therapeutic target to decrease morbidity and mortality in this population.

Neutrophil-Derived Exosomes Induce M1 Macrophage Polarization and Prime Macrophage Pyroptosis via miR-30d-5p in Sepsis

2021 ◽  
Author(s):  
Yang Jiao ◽  
Ti Zhang ◽  
Chengmi Zhang ◽  
Haiying Ji ◽  
Xingyu Tong ◽  
...  
Keyword(s):  
Macrophage Activation ◽  
Macrophage Polarization ◽  
Cecal Ligation ◽  
Polymorphonuclear Neutrophils ◽  
Raw264.7 Macrophages ◽  
M1 Macrophage ◽  
Tnf Α

Abstract Background: Polymorphonuclear neutrophils (PMNs) have been demonstrated to play a role in proinflammatory M1 activation and macrophage (Mϕ) pyroptosis in sepsis. Accumulating evidence suggests PMN-derived exosomes as a new subcellular entity acting as a fundamental link between PMN-driven inflammation and tissue damage. However, the role of PMN-derived exosomes in sepsis remains unclear. This study aimed to determine whether PMN-derived exosomes play a role in proinflammatory M1 activation and Mϕ pyroptosis in sepsis and explore the potential mechanisms involved. Methods: Exosomes were isolated from the supernatant of PMNs activated with phosphate buffered saline (PBS) or tumor necrosis factor (TNF)-α, cocultured with Raw264.7 macrophages or BMDMs, and then assayed for macrophage polarization and pyroptosis. To examine the role of exosomes in vivo, PMN-derived exosomes were administered to mice, and then examined for lung inflammation. Results: After activated by TNF-α, PMNs released exosomes (TNF-Exo) to promote M1 macrophage activation both in vivo and in vitro. In addition, TNF-Exo primed macrophages for pyroptosis by upregulating NLRP3 inflammasome expression through NF-κB signaling pathway. Mechanistic studies demonstrated that miR-30d-5p mediated the function of TNF-Exo by targeting SOCS-1 and SIRT1 in macrophages. Furthermore, treatment of miR-30d-5p inhibitors in vivo significantly decreased cecal ligation and puncture (CLP) or TNF-Exo-induced M1 macrophage activation and macrophage death in the lung. Lung injury was also alleviated by miR-30d-5p inhibitors.Conclusions: In this study, we identified a novel mechanism of PMN-Mϕ interaction in sepsis, demonstrating that exosomal miR-30d-5p from PMNs induced M1 macrophage polarization and primed Mϕ for pyroptosis by activating NF-κB signaling. These findings suggest a previously unidentified role of neutrophil-derived exosomes in sepsis and may lead to new therapeutic approaches.

Sign in / Sign up

Export Citation Format

Share Document