scholarly journals DNMT3b-mediated methylation of ZSWIM3 enhances inflammation in alcohol-induced liver injury via regulating TRAF2-mediated NF-κB pathway

2020 ◽  
Vol 134 (14) ◽  
pp. 1935-1956 ◽  
Author(s):  
Hai-Di Li ◽  
Xin Chen ◽  
Jie-Jie Xu ◽  
Xiao-Sa Du ◽  
Yang Yang ◽  
...  
Keyword(s):  
Liver Injury ◽  
Zinc Finger ◽  
Inflammatory Responses ◽  
Tumor Necrosis Factor Receptor ◽  
Dna Methyltransferases ◽  
Aberrant Expression ◽  
Ethanol Feeding ◽  
And Function

Abstract The regulation of macrophages during inflammatory responses is a crucial process in alcoholic liver disease (ALD) and aberrant macrophage DNA methylation is associated with inflammation. Our preliminary screening results of macrophage methylation in the present study demonstrated the zinc finger SWI2/SNF2 and MuDR (SWIM)-domain containing 3 (ZSWIM3) were hypermethylated in the 5′ untranslated region (5′-UTR) region. ZSWIM3, a novel zinc finger-chelate domain of SWIM, is predicted to function in DNA-binding and protein-binding interactions. Its expression was found to be consistently decreased in macrophages isolated from livers of ethyl alcohol (EtOH)-fed mice and in EtOH+lipopolysaccharide (LPS)-induced RAW264.7 cells. Over-expression of ZSWIM3 was found to attenuate chronic+binge ethanol feeding-induced liver injury and inhibit inflammatory responses in vivo. Enforced expression of ZSWIM3 in vitro was also found to have anti-inflammatory effects. Aberrant expression of ZSWIM3 in alcohol-induced liver injury (ALI) was found to be associated with hypermethylation. Analysis of CpG prediction indicated the presence of two methylated sites in the ZSWIM3 promoter region and methylation inhibitor and DNA methyltransferases (DNMTs)-siRNA transfection were found to restore down-regulated ZSWIM3. Chromatin immunoprecipitation (ChIP) assay and molecular docking affirmed the role of DNMT 3b (DNMT3b) as a principal regulator of ZSWIM3 expression. Mechanistically, ZSWIM3 might affect inflammation by binding with tumor necrosis factor receptor-associated factor 2 (TRAF2), which further mediates the activation of the nuclear transcription factor κB (NF-κB) pathway. The present study, therefore, provides detailed insights into the possible structure and function of ZSWIM3 and thus, contributes new substantial research in the elucidation of the pathogenesis of ALI.

scholarly journals IL-22 ameliorates LPS-induced acute liver injury by autophagy activation through ATF4-ATG7 signaling

2020 ◽  
Vol 11 (11) ◽  
Author(s):  
Lujing Shao ◽  
Xi Xiong ◽  
Yucai Zhang ◽  
Huijie Miao ◽  
Yuqian Ren ◽  
...  
Keyword(s):  
Liver Injury ◽  
Inflammatory Responses ◽  
Acute Liver Injury ◽  
Mrna Levels ◽  
Protective Effects ◽  
Activating Transcription Factor 4 ◽  
Pre Treatment ◽  
Underlying Mechanisms

Abstract Uncontrollable inflammatory response acts as a driver of sepsis-associated liver injury (SALI). IL-22 plays an important role in regulating inflammatory responses, but its role in SALI remains unknown. The aim of the study was to assess the association of serum IL-22 with SALI in pediatric patients and to enclose the underlying mechanisms of IL-22 involved in lipopolysaccharide (LPS) - induced acute liver injury (ALI) in mice. Serum IL-22 levels in patients with SALI were significantly lower than in septic patients without liver injury, and the area under receiver operating characteristic (ROC) curve of IL-22 for discriminating SALI was 0.765 (95% CI: 0.593–0.937). Pre-administration of recombinant murine IL-22 alleviated LPS-induced ALI in mice, and serum IL-6 levels and the mRNA levels of TNF-α, IL-1β, and IL-6 in livers were decreased in response to IL-22 pre-treatment in mice. More importantly, IL-22 pre-treatment activated hepatic autophagy mediated by activating transcription factor 4 (ATF4)-autophagy-related gene 7 (ATG7) signaling in vivo and in vitro in response to LPS administration. Moreover, knockdown of ATF4 in mice aggravated LPS-induced ALI, which was associated with suppressed ATG7-related autophagy. In addition, the protective effects of IL-22 on LPS-induced ALI was partially blocked by ATF4 knockdown, which was associated with lower expression of LC3II/I in the livers of ATF4 knockdown (HT or Atf4+/−) mice compared with wild-type mice (WT or Atf4+/+) mice. In conclusion, low serum IL-22 level is associated with SALI occurrence, and IL-22 pre-administration activates autophagy in hepatocytes and protects mice against LPS-induced ALI partially related to ATF4-ATG7 signaling pathway.

Protective Effect of Dihydrokaempferol on Acetaminophen-Induced Liver Injury by Activating the SIRT1 Pathway

2021 ◽  
pp. 1-14
Author(s):  
Jiaqi Zhang ◽  
Cheng Hu ◽  
Xiulong Li ◽  
Li Liang ◽  
Mingcai Zhang ◽  
...  
Keyword(s):  
Liver Injury ◽  
Protective Effect ◽  
Western Blotting ◽  
Inflammatory Responses ◽  
Chinese Herbs ◽  
Western World ◽  
Dependent Manner ◽  
Stress Injury

Acetaminophen (APAP) overdose is the leading cause of acute liver failure (ALF) in the Western world, with limited treatment opportunities. 3,5,7,4[Formula: see text]-Tetrahydroxyflavanone (Dihydrokaempferol, DHK, Aromadendrin) is a flavonoid isolated from Chinese herbs and displays high anti-oxidant and anti-inflammatory capacities. In this study, we investigated the protective effect by DHK against APAP-induced liver injury in vitro and in vivo and the potential mechanism of action. Cell viability assays were used to determine the effects of DHK against APAP-induced liver injury. The levels of reactive oxygen species (ROS), serum alanine/aspartate aminotransferases (ALT/AST), liver myeloperoxidase (MPO), and malondialdehyde (MDA) were measured and analyzed to evaluate the effects of DHK on APAP-induced liver injury. Western blotting, immunofluorescence staining, RT-PCR, and Transmission Electron Microscope were carried out to detect the signaling pathways affected by DHK. Here, we found that DHK owned a protective effect on APAP-induced liver injury with a dose-dependent manner. Meanwhile, Western blotting showed that DHK promoted SIRT1 expression and autophagy, activated the NRF2 pathway, and inhibited the translocation of nuclear p65 (NF-[Formula: see text]B) in the presence of APAP. Furthermore, SIRT1 inhibitor EX-527 aggravated APAP-induced hepatotoxicity when treating with DHK. Molecular docking results suggested potential interaction between DHK and SIRT1. Taken together, our study demonstrates that DHK protects against APAP-induced liver injury by activating the SIRT1 pathway, thereby promoting autophagy, reducing oxidative stress injury, and inhibiting inflammatory responses.

scholarly journals Baicalin Attenuates Alcoholic Liver Injury through Modulation of Hepatic Oxidative Stress, Inflammation and Sonic Hedgehog Pathway in Rats

2016 ◽  
Vol 39 (3) ◽  
pp. 1129-1140 ◽  
Author(s):  
Huifen Wang ◽  
Yanli Zhang ◽  
Ruxue Bai ◽  
Miao Wang ◽  
Shiyu Du
Keyword(s):  
Oxidative Stress ◽  
Liver Injury ◽  
Sonic Hedgehog ◽  
Inflammatory Responses ◽  
Hedgehog Pathway ◽  
Alcoholic Liver Injury ◽  
Sonic Hedgehog Pathway ◽  
Shh Pathway

Background/Aims: Lipid accumulation, inflammatory responses and oxidative stress have been implicated in the pathology of alcoholic liver disease (ALD). Targeting inhibition of these features may provide a promising therapeutic strategy for ALD. Baicalin, a flavonoid isolated from Scutellaria baicalensis Georgi, has been shown to exert a hepatoprotective effect. However, its effects on ALD remain obscure. This study was aimed to investigate the effects of baicalin on alcohol-induced liver injury and its related mechanisms. Methods: For in vivo experiments, rats were supplied intragastrical administration of alcohol continuously for 4 or 8 weeks, and then received baicalin treatment in the latter 4 weeks in the presence / absence of alcohol intake. Liver histology and function, inflammatory cytokines, oxidative mediators, and the components of the Sonic hedgehog pathway were evaluated. For in vitro experiments, alcohol-stimulated human normal liver cells LO2 were used. Results: Baicalin treatment significantly alleviated alcoholic liver injury, improved liver function impaired by alcohol, and inhibited hepatocytes apoptosis. In addition, baicalin decreased the expression levels of proinflammatory cytokines TNF-α, IL-1β, IL-6) and malonyldialdehyde (MDA), and increased the activities of antioxidant enzymes SOD and GSH-Px. Furthermore, baicalin modulated the activation of Sonic hedgehog (Shh) pathway. Administration of baicalin upregulated the expression of sonic hedgehog (Shh), patched (Ptc), Smoothened (Smo), and Glioblastoma-1(Gli-1). Blockade of the Shh pathway in cyclopamine abolished the effects of baicalin in vitro. Conclusion: Both in vivo and in vitro experimental results indicate that baicalin exerts hepatoprotective roles in alcohol-induced liver injury through inhibiting oxidative stress, inflammatory response, and the regulation of the Shh pathway.

scholarly journals Chronic Ethanol Feeding Modulates Inflammatory Mediators, Activation of Nuclear Factor-κB, and Responsiveness to Endotoxin in Murine Kupffer Cells and Circulating Leukocytes

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Miriam Maraslioglu ◽  
Elsie Oppermann ◽  
Carolin Blattner ◽  
Roxane Weber ◽  
Dirk Henrich ◽  
...  
Keyword(s):  
Inflammatory Mediators ◽  
Inflammatory Responses ◽  
Nuclear Factor Κb ◽  
Intracellular Signalling ◽  
Chronic Ethanol ◽  
Dependent Manner ◽  
Nuclear Factor ◽  
Ethanol Feeding

Chronic ethanol abuse is known to increase susceptibility to infections after injury, in part, by modification of macrophage function. Several intracellular signalling mechanisms are involved in the initiation of inflammatory responses, including the nuclear factor-κB (NF-κB) pathway. In this study, we investigated the systemic and hepatic effect of chronic ethanol feeding onin vivoactivation of NF-κB in NF-κBEGFPreporter gene mice. Specifically, the study focused on Kupffer cell proinflammatory cytokines IL-6 and TNF-αand activation of NF-κB after chronic ethanol feeding followed byin vitrostimulation with lipopolysaccharide (LPS). We found that chronic ethanol upregulated NF-κB activation and increased hepatic and systemic proinflammatory cytokine levels. Similarly, LPS-stimulated IL-1βrelease from whole blood was significantly enhanced in ethanol-fed mice. However, LPS significantly increased IL-6 and TNF-αlevels. These results demonstrate that chronic ethanol feeding can improve the responsiveness of macrophage LPS-stimulated IL-6 and TNF-αproduction and indicate that this effect may result from ethanol-induced alterations in intracellular signalling through NF-κB. Furthermore, LPS and TNF-αstimulated the gene expression of different inflammatory mediators, in part, in a NF-κB-dependent manner.

scholarly journals Macrophages Modulate Hepatic Injury Involving NLRP3 Inflammasome: The Example of Efavirenz

Biomedicines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 109
Author(s):  
Fernando Alegre ◽  
Alberto Martí-Rodrigo ◽  
Miriam Polo ◽  
Dolores Ortiz-Masiá ◽  
Celia Bañuls ◽  
...  
Keyword(s):  
Liver Injury ◽  
Liver Cell ◽  
Nlrp3 Inflammasome ◽  
Inflammatory Responses ◽  
Macrophage Polarization ◽  
Cell Types ◽  
Drug Induced ◽  
Anti Inflammatory

Drug-induced liver injury (DILI) constitutes a clinical challenge due to the incomplete characterization of the mechanisms involved and potential risk factors. Efavirenz, an anti-HIV drug, induces deleterious actions in hepatocytes that could underlie induction of the NLRP3 inflammasome, an important regulator of inflammatory responses during liver injury. We assessed the potential of efavirenz to modulate the inflammatory and fibrogenic responses of major liver cell types involved in DILI. The effects of efavirenz were evaluated both in vitro and in vivo. Efavirenz triggered inflammation in hepatocytes, in a process that involved NF-κB and the NLRP3 inflammasome, and activated hepatic stellate cells (HSCs), thereby enhancing expression of inflammatory and fibrogenic markers. The NLRP3 inflammasome was not altered in efavirenz-treated macrophages, but these cells polarized towards the anti-inflammatory M2 phenotype and displayed upregulated anti-inflammatory mediators. Conversely, no evidence of damage was observed in efavirenz-treated animals, except when macrophages were depleted, which resulted in the in vivo manifestation of the deleterious effects detected in hepatocytes and HSCs. Efavirenz elicits a cell-specific activation of the NLRP3 inflammasome in hepatocytes and HSCs, but macrophages appear to counteract efavirenz-induced liver injury. Our results highlight the dynamic nature of the interaction among liver cell populations and emphasize the potential of targeting macrophage polarization as a strategy to treat NLRP3 inflammasome-induced liver injury.

scholarly journals Regulation of inflammatory responses by IL-17F

2008 ◽  
Vol 205 (5) ◽  
pp. 1063-1075 ◽  
Author(s):  
Xuexian O. Yang ◽  
Seon Hee Chang ◽  
Heon Park ◽  
Roza Nurieva ◽  
Bhavin Shah ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Severe Disease ◽  
Tumor Necrosis Factor Receptor ◽  
Allergen Challenge ◽  
Autoimmune Encephalomyelitis ◽  
Important Regulator ◽  
Proinflammatory Gene

Although interleukin (IL) 17 has been extensively characterized, the function of IL-17F, which has an expression pattern regulated similarly to IL-17, is poorly understood. We show that like IL-17, IL-17F regulates proinflammatory gene expression in vitro, and this requires IL-17 receptor A, tumor necrosis factor receptor–associated factor 6, and Act1. In vivo, overexpression of IL-17F in lung epithelium led to infiltration of lymphocytes and macrophages and mucus hyperplasia, similar to observations made in IL-17 transgenic mice. To further understand the function of IL-17F, we generated and analyzed mice deficient in IL-17F or IL-17. IL-17, but not IL-17F, was required for the initiation of experimental autoimmune encephalomyelitis. Mice deficient in IL-17F, but not IL-17, had defective airway neutrophilia in response to allergen challenge. Moreover, in an asthma model, although IL-17 deficiency reduced T helper type 2 responses, IL-17F–deficient mice displayed enhanced type 2 cytokine production and eosinophil function. In addition, IL-17F deficiency resulted in reduced colitis caused by dextran sulfate sodium, whereas IL-17 knockout mice developed more severe disease. Our results thus demonstrate that IL-17F is an important regulator of inflammatory responses that seems to function differently than IL-17 in immune responses and diseases.

scholarly journals A key role for ATF3 in regulating mast cell survival and mediator release

Blood ◽  
2010 ◽  
Vol 115 (23) ◽  
pp. 4734-4741 ◽  
Author(s):  
Mark Gilchrist ◽  
William R. Henderson ◽  
Andrew Morotti ◽  
Carrie D. Johnson ◽  
Alex Nachman ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Leucine Zipper ◽  
Inflammatory Responses ◽  
Immunoglobulin E ◽  
Allergic Diseases ◽  
Activating Transcription Factor 3 ◽  
Basic Leucine Zipper ◽  
And Function

Abstract Activating transcription factor 3 (ATF3) is a basic leucine zipper transcription factor that plays a regulatory role in inflammation, cell division, and apoptosis. Mast cells (MCs) initiate many inflammatory responses and have a central role in allergy and allergic diseases. We report here that ATF3 has a central role in MC development and function. Bone marrow–derived MC populations from ATF3-deficient mice are unresponsive to interleukin-3 (IL-3)–induced maturation signals, and this correlates with increased apoptosis, diminished activation of the Akt kinase, and decreased phosphorylation of the proapoptotic protein Bad. Furthermore, ATF3-null mice lacked MCs in the peritoneum and dermis, showing that the in vitro results are recapitulated in vivo. ATF3-null MCs also showed functional defects; high-affinity immunoglobulin E receptor–mediated degranulation was significantly inhibited, whereas IL-4 and IL-6 expression was enhanced. This dual role of ATF3 provides insight into the complex interplay between MC development and its subsequent physiologic role.

scholarly journals Lipoproteins Are Responsible for the Pro-Inflammatory Property of Staphylococcus aureus Extracellular Vesicles

2021 ◽  
Vol 22 (13) ◽  
pp. 7099
Author(s):  
Pradeep Kumar Kopparapu ◽  
Meghshree Deshmukh ◽  
Zhicheng Hu ◽  
Majd Mohammad ◽  
Marco Maugeri ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Inflammatory Responses ◽  
Surface Proteins ◽  
Host Cells ◽  
Immune Stimulation ◽  
Domains Of Life ◽  
Major Surface ◽  
Staphylococcal Aureus

Staphylococcal aureus (S. aureus), a Gram-positive bacteria, is known to cause various infections. Extracellular vesicles (EVs) are a heterogeneous array of membranous structures secreted by cells from all three domains of life, i.e., eukaryotes, bacteria, and archaea. Bacterial EVs are implied to be involved in both bacteria–bacteria and bacteria–host interactions during infections. It is still unclear how S. aureus EVs interact with host cells and induce inflammatory responses. In this study, EVs were isolated from S. aureus and mutant strains deficient in either prelipoprotein lipidation (Δlgt) or major surface proteins (ΔsrtAB). Their immunostimulatory capacities were assessed both in vitro and in vivo. We found that S. aureus EVs induced pro-inflammatory responses both in vitro and in vivo. However, this activity was dependent on lipidated lipoproteins (Lpp), since EVs isolated from the Δlgt showed no stimulation. On the other hand, EVs isolated from the ΔsrtAB mutant showed full immune stimulation, indicating the cell wall anchoring of surface proteins did not play a role in immune stimulation. The immune stimulation of S. aureus EVs was mediated mainly by monocytes/macrophages and was TLR2 dependent. In this study, we demonstrated that not only free Lpp but also EV-imbedded Lpp had high pro-inflammatory activity.

scholarly journals Involvement of HECTD1 in LPS-induced astrocyte activation via σ-1R-JNK/p38-FOXJ2 axis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ying Tang ◽  
Mengchun Zhou ◽  
Rongrong Huang ◽  
Ling Shen ◽  
Li Yang ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Astrocyte Activation ◽  
Hect Domain ◽  
P38 Inhibitor ◽  
Ubiquitin Protein Ligase ◽  
Primary Mouse ◽  
Lps Treatment

Abstract Background Astrocytes participate in innate inflammatory responses within the mammalian central nervous system (CNS). HECT domain E3 ubiquitin protein ligase 1 (HECTD1) functions during microglial activation, suggesting a connection with neuroinflammation. However, the potential role of HECTD1 in astrocytes remains largely unknown. Results Here, we demonstrated that HECTD1 was upregulated in primary mouse astrocytes after 100 ng/ml lipopolysaccharide (LPS) treatment. Genetic knockdown of HECTD1 in vitro or astrocyte-specific knockdown of HECTD1 in vivo suppressed LPS-induced astrocyte activation, whereas overexpression of HECTD1 in vitro facilitated LPS-induced astrocyte activation. Mechanistically, we established that LPS activated σ-1R-JNK/p38 pathway, and σ-1R antagonist BD1047, JNK inhibitor SP600125, or p38 inhibitor SB203580 reversed LPS-induced expression of HECTD1, thus restored LPS-induced astrocyte activation. In addition, FOXJ2 functioned as a transcription factor of HECTD1, and pretreatment of primary mouse astrocytes with BD1047, SB203580, and SP600125 significantly inhibited LPS-mediated translocation of FOXJ2 into the nucleus. Conclusions Overall, our present findings suggest that HECTD1 participates in LPS-induced astrocyte activation by activation of σ-1R-JNK/p38-FOXJ2 pathway and provide a potential therapeutic strategy for neuroinflammation induced by LPS or any other neuroinflammatory disorders.

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