Functional Interplay between Methyltransferases and Inflammasomes in Inflammatory Responses and Diseases

An inflammasome is an intracellular protein complex that is activated in response to a pathogenic infection and cellular damage. It triggers inflammatory responses by promoting inflammatory cell death (called pyroptosis) and the secretion of pro-inflammatory cytokines, interleukin (IL)-1β and IL-18. Many types of inflammasomes have been identified and demonstrated to play a central role in inducing inflammatory responses, leading to the onset and progression of numerous inflammatory diseases. Methylation is a biological process by which methyl groups are transferred from methyl donors to proteins, nucleic acids, and other cellular molecules. Methylation plays critical roles in various biological functions by modulating gene expression, protein activity, protein localization, and molecular stability, and aberrant regulation of methylation causes deleterious outcomes in various human diseases. Methylation is a key determinant of inflammatory responses and diseases. This review highlights the current understanding of the functional relationship between inflammasome regulation and methylation of cellular molecules in inflammatory responses and diseases.

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Load Down-Regulates TNF-Alpha Induced Cartilage Degradation in Part Through NF-KB and P38 Pathways

ASME 2007 Summer Bioengineering Conference ◽

10.1115/sbc2007-176541 ◽

2007 ◽

Author(s):

Valerie M. Wolfe ◽

Seonghun Park ◽

Marjana Tomic ◽

Peter A. Torzilli ◽

C. T. Christopher Chen

Keyword(s):

Inflammatory Responses ◽

Inflammatory Diseases ◽

Interleukin 1 ◽

Tensile Load ◽

Cartilage Degradation ◽

Acute Injury ◽

Cyclic Compression ◽

Tnf Α ◽

Necrosis Factor ◽

Pro Inflammatory Cytokines

Pro-inflammatory cytokines, such as interleukin-1 (IL-1) and tumor necrosis factor (TNF), can induce cartilage degradation after acute injury or in inflammatory diseases [1,2,3,7]. The degradative events are coordinated through the elevation and activation of two classes of enzymes, namely matrix metalloproteinases (MMPs) and aggrecanases (ADAMTS-4 and −5) [1,6]. Prior studies suggested that pro-inflammatory responses induced by IL-1β can be inhibited by tensile load [2] and more recently by cyclic compression [8]. It is, however, not clear whether load affects other cytokines, such as TNF-α. TNF-α is known to bind its receptor (TNFR1) to cause a cascade that ends with degradation of an inhibitor, IκBα, and release of the transcription factor NF-κB [3]. The actions of TNF-α are also known to be affected by at least three NF-κB independent pathways including the p38, ERK, and JNK pathways [4]. The objective of this study was to determine whether cyclic compression could affect TNF-α induced cartilage degradation and to determine the roles of p38, ERK, and JNK pathways in TNF-induced cartilage degradation. We hypothesized that cyclic loading would inhibit the degradative effects caused by TNF-α.

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Antiulcer Activity of Steamed Ginger Extract against Ethanol/HCl-Induced Gastric Mucosal Injury in Rats

Molecules ◽

10.3390/molecules25204663 ◽

2020 ◽

Vol 25 (20) ◽

pp. 4663

Author(s):

Jun-Kyu Shin ◽

Jae Hyeon Park ◽

Kyeong Seok Kim ◽

Tong Ho Kang ◽

Hyung Sik Kim

Keyword(s):

Inflammatory Cytokines ◽

Inflammatory Responses ◽

Inflammatory Diseases ◽

Folk Medicine ◽

Nuclear Factor Κb ◽

Gastric Ulcers ◽

Antiulcer Activity ◽

Ginger Extract ◽

Nitrite Production ◽

Pro Inflammatory Cytokines

Ginger (Zingiber officianale), the most widely consumed species, is traditionally used as a folk medicine to treat some inflammatory diseases in China and Korea. However, the functional activity of steamed ginger extract on gastric ulcers has not been previously explored. The present study aimed to investigate antiulcer activity of steamed ginger extract (GGE03) against ethanol (EtOH)/HCl-induced gastric ulcers in a rat model. GGE03 (100 mg/kg) was orally administered for 14 days to rats before oral intubation of an EtOH/HCl mixture to induce gastric damage. Pretreatment with GGE03 markedly protected the formation of microscopic pathological damage in the gastric mucosa. Further, administration of GGE03 significantly increased mucosal total nitrate/nitrite production in gastric tissues, and elevated total GSH content, catalase activity and superoxide dismutase (SOD) expression as well as decreasing lipid peroxidation and myeloperoxidase (MPO) activity. Underlying protective mechanisms were examined by assessing inflammation-related genes, including nuclear factor-κB (NF-κB), prostaglandin E2 (PGE2), and pro-inflammatory cytokines levels. GGE03 administration significantly reduced the expression of NF-κB and pro-inflammatory cytokines. Our findings suggest that GGE03 possesses antiulcer activity by attenuating oxidative stress and inflammatory responses.

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Interleukin-38 ameliorates poly(I:C) induced lung inflammation: therapeutic implications in respiratory viral infections

Cell Death and Disease ◽

10.1038/s41419-020-03283-2 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Xun Gao ◽

Paul Kay Sheung Chan ◽

Grace Chung Yan Lui ◽

David Shu Cheong Hui ◽

Ida Miu-Ting Chu ◽

...

Keyword(s):

Inflammatory Cytokines ◽

Viral Infections ◽

Inflammatory Responses ◽

Inflammatory Diseases ◽

Poly I:C ◽

Therapeutic Implications ◽

Cytokines And Chemokines ◽

Respiratory Viral Infections ◽

Pro Inflammatory Cytokines

AbstractInterleukin-38 has recently been shown to have anti-inflammatory properties in lung inflammatory diseases. However, the effects of IL-38 in viral pneumonia remains unknown. In the present study, we demonstrate that circulating IL-38 concentrations together with IL-36α increased significantly in influenza and COVID-19 patients, and the level of IL-38 and IL-36α correlated negatively and positively with disease severity and inflammation, respectively. In the co-cultured human respiratory epithelial cells with macrophages to mimic lung microenvironment in vitro, IL-38 was able to alleviate inflammatory responses by inhibiting poly(I:C)-induced overproduction of pro-inflammatory cytokines and chemokines through intracellular STAT1, STAT3, p38 MAPK, ERK1/2, MEK, and NF-κB signaling pathways. Intriguingly, transcriptomic profiling revealed that IL-38 targeted genes were associated with the host innate immune response to virus. We also found that IL-38 counteracts the biological processes induced by IL-36α in the co-culture. Furthermore, the administration of recombinant IL-38 could mitigate poly I:C-induced lung injury, with reduced early accumulation of neutrophils and macrophages in bronchoalveolar lavage fluid, activation of lymphocytes, production of pro-inflammatory cytokines and chemokines and permeability of the alveolar-epithelial barrier. Taken together, our study indicates that IL-38 plays a crucial role in protection from exaggerated pulmonary inflammation during poly(I:C)-induced pneumonia, thereby providing the basis of a novel therapeutic target for respiratory viral infections.

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The Immunomodulatory Role of G2013 (α-L-Guluronic Acid) on the Expression of TLR2 and TLR4 in HT29 cell line

Current Drug Discovery Technologies ◽

10.2174/1570163815666180226093711 ◽

2019 ◽

Vol 16 (1) ◽

pp. 91-95 ◽

Cited By ~ 4

Author(s):

Hamid Farhang ◽

Laleh Sharifi ◽

Mohammad Mehdi Soltan Dallal ◽

Mona Moshiri ◽

Zahra Norouzbabaie ◽

...

Keyword(s):

Inflammatory Responses ◽

Inflammatory Diseases ◽

Rna Extraction ◽

Cell Plate ◽

Inhibitory Effect ◽

Control Group ◽

Ht29 Cells ◽

Guluronic Acid ◽

Tlr4 Mrna

Background: The non-steroidal anti-inflammatory drugs (NSAIDs) play crucial role in the controlling of inflammatory diseases. Due to the vast side effects of NSAIDs, its use is limited. G2013 or &#945;-L-Guluronic Acid is a new NSAID with immunomodulatory features. Objectives: Considering the leading role of TLRs in inflammatory responses, in this study, we aimed to evaluate G2013 cytotoxicity and its effect on the expression of TLR2 and TLR4 molecules. Methods: HEK293-TLR2 and HEK293-TLR4 cells were cultured and seeded on 96-well cell plate, and MTT assay was performed for detecting the viability of the cells after treatment with different concentrations of G2013. HT29 cells were grown and treated with low and high doses of G2013. After total RNA extraction and cDNA synthesis, quantitative real-time PCR were performed to assess the TLR2 and TLR4 mRNA synthesis. Results: We found that concentrations of ≤125 &#181;g/ml of G2013 had no apparent cytotoxicity effect on the HEK293-TLR2 and -TLR4 cells. Our results indicated that after G2013 treatment (5 &#181;g/ml) in HT29 cells, TLR2 and TLR4 mRNA expression decreased significantly compared with the untreated control group (p=0.02 and p=0.001 respectively). Conclusion: The results of this study revealed that G2013 can down regulate the TLR2 and TLR4 gene expression and exerts its inhibitory effect. Our findings are parallel to our previous finding which showed G2013 ability to down regulate the signaling pathway of TLRs. However, further studies are needed to identify the molecular mechanism of G2013.<p>

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Punicalagin Prevents Inflammation in LPS-Induced RAW264.7 Macrophages by Inhibiting FoxO3a/Autophagy Signaling Pathway

Nutrients ◽

10.3390/nu11112794 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2794 ◽

Cited By ~ 8

Author(s):

Cao ◽

Chen ◽

Ren ◽

Zhang ◽

Tan ◽

...

Keyword(s):

Western Blot ◽

Signaling Pathway ◽

Inflammatory Cytokines ◽

Blot Analysis ◽

Western Blot Analysis ◽

Inflammatory Responses ◽

Raw264.7 Macrophages ◽

Tnf Α ◽

Autophagy Inhibition ◽

Pro Inflammatory Cytokines

Punicalagin, a hydrolysable tannin of pomegranate juice, exhibits multiple biological effects, including inhibiting production of pro-inflammatory cytokines in macrophages. Autophagy, an intracellular self-digestion process, has been recently shown to regulate inflammatory responses. In this study, we investigated the anti-inflammatory potential of punicalagin in lipopolysaccharide (LPS) induced RAW264.7 macrophages and uncovered the underlying mechanisms. Punicalagin significantly attenuated, in a concentration-dependent manner, LPS-induced release of NO and decreased pro-inflammatory cytokines TNF-α and IL-6 release at the highest concentration. We found that punicalagin inhibited NF-κB and MAPK activation in LPS-induced RAW264.7 macrophages. Western blot analysis revealed that punicalagin pre-treatment enhanced LC3II, p62 expression, and decreased Beclin1 expression in LPS-induced macrophages. MDC assays were used to determine the autophagic process and the results worked in concert with Western blot analysis. In addition, our observations indicated that LPS-induced releases of NO, TNF-α, and IL-6 were attenuated by treatment with autophagy inhibitor chloroquine, suggesting that autophagy inhibition participated in anti-inflammatory effect. We also found that punicalagin downregulated FoxO3a expression, resulting in autophagy inhibition. Overall these results suggested that punicalagin played an important role in the attenuation of LPS-induced inflammatory responses in RAW264.7 macrophages and that the mechanisms involved downregulation of the FoxO3a/autophagy signaling pathway.

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Flavonoids: Nutraceuticals for Rheumatic Diseases via Targeting of Inflammasome Activation

International Journal of Molecular Sciences ◽

10.3390/ijms22020488 ◽

2021 ◽

Vol 22 (2) ◽

pp. 488

Author(s):

Young-Su Yi

Keyword(s):

Rheumatic Diseases ◽

Fruits And Vegetables ◽

Inflammatory Responses ◽

Protein Complexes ◽

Cellular Damage ◽

Inflammatory Rheumatic Diseases ◽

Inflammasome Activation ◽

Central Feature ◽

Inflammatory Protein ◽

Anti Inflammatory

Inflammation, an innate immune response that prevents cellular damage caused by pathogens, consists of two successive mechanisms, namely priming and triggering. While priming is an inflammation-preparation step, triggering is an inflammation-activation step, and the central feature of triggering is the activation of inflammasomes and intracellular inflammatory protein complexes. Flavonoids are natural phenolic compounds predominantly present in plants, fruits, and vegetables and are known to possess strong anti-inflammatory activities. The anti-inflammatory activity of flavonoids has long been demonstrated, with the main focus on the priming mechanisms, while increasing numbers of recent studies have redirected the research focus on the triggering step, and studies have reported that flavonoids inhibit inflammatory responses and diseases by targeting inflammasome activation. Rheumatic diseases are systemic inflammatory and autoimmune diseases that primarily affect joints and connective tissues, and they are associated with numerous deleterious effects. Here, we discuss the emerging literature on the ameliorative role of flavonoids targeting inflammasome activation in inflammatory rheumatic diseases.

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Skullcapflavone II Suppresses TNF-α/IFN-γ-Induced TARC, MDC, and CTSS Production in HaCaT Cells

International Journal of Molecular Sciences ◽

10.3390/ijms22126428 ◽

2021 ◽

Vol 22 (12) ◽

pp. 6428

Author(s):

Hanon Lee ◽

Dong Hun Lee ◽

Jang-Hee Oh ◽

Jin Ho Chung

Keyword(s):

P38 Mapk ◽

Therapeutic Potential ◽

Inflammatory Diseases ◽

Mapk Signaling ◽

Hacat Cells ◽

Protein Levels ◽

Tnf Α ◽

Ifn Γ ◽

Mapk Signaling Pathways ◽

Pro Inflammatory Cytokines

Skullcapflavone II (SFII), a flavonoid derived from Scutellaria baicalensis, has been reported to have anti-inflammatory properties. However, its therapeutic potential for skin inflammatory diseases and its mechanism are unknown. Therefore, this study aimed to investigate the effect of SFII on TNF-α/IFN-γ-induced atopic dermatitis (AD)-associated cytokines, such as thymus- and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC). Co-stimulation with TNF-α/IFN-γ in HaCaT cells is a well-established model for induction of pro-inflammatory cytokines. We treated cells with SFII prior to TNF-α/IFN-γ-stimulation and confirmed that it significantly inhibited TARC and MDC expression at the mRNA and protein levels. Additionally, SFII also inhibited the expression of cathepsin S (CTSS), which is associated with itching in patients with AD. Using specific inhibitors, we demonstrated that STAT1, NF-κB, and p38 MAPK mediate TNF-α/IFN-γ-induced TARC and MDC, as well as CTSS expression. Finally, we confirmed that SFII significantly suppressed TNF-α/IFN-γ-induced phosphorylation of STAT1, NF-κB, and p38 MAPK. Taken together, our study indicates that SFII inhibits TNF-α/IFN-γ-induced TARC, MDC, and CTSS expression by regulating STAT1, NF-κB, and p38 MAPK signaling pathways.

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Novel Insights into YB-1 Signaling and Cell Death Decisions

Cancers ◽

10.3390/cancers13133306 ◽

2021 ◽

Vol 13 (13) ◽

pp. 3306

Author(s):

Aneri Shah ◽

Jonathan A. Lindquist ◽

Lars Rosendahl ◽

Ingo Schmitz ◽

Peter R. Mertens

Keyword(s):

Stress Responses ◽

Rna Splicing ◽

Cell Cycle Progression ◽

Rna Binding ◽

Inflammatory Responses ◽

Rna Binding Proteins ◽

Inflammatory Diseases ◽

Therapeutic Option ◽

Tumor Therapy ◽

Inflammatory Microenvironment

YB-1 belongs to the evolutionarily conserved cold-shock domain protein family of RNA binding proteins. YB-1 is a well-known transcriptional and translational regulator, involved in cell cycle progression, DNA damage repair, RNA splicing, and stress responses. Cell stress occurs in many forms, e.g., radiation, hyperthermia, lipopolysaccharide (LPS) produced by bacteria, and interferons released in response to viral infection. Binding of the latter factors to their receptors induces kinase activation, which results in the phosphorylation of YB-1. These pathways also activate the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), a well-known transcription factor. NF-κB is upregulated following cellular stress and orchestrates inflammatory responses, cell proliferation, and differentiation. Inflammation and cancer are known to share common mechanisms, such as the recruitment of infiltrating macrophages and development of an inflammatory microenvironment. Several recent papers elaborate the role of YB-1 in activating NF-κB and signaling cell survival. Depleting YB-1 may tip the balance from survival to enhanced apoptosis. Therefore, strategies that target YB-1 might be a viable therapeutic option to treat inflammatory diseases and improve tumor therapy.

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Mutant glucocorticoid receptor binding elements on the interleukin-6 promoter regulate dexamethasone effects

BMC Immunology ◽

10.1186/s12865-021-00413-z ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Wen-Teng Chang ◽

Ming-Yuan Hong ◽

Chien-Liang Chen ◽

Chi-Yuan Hwang ◽

Cheng-Chieh Tsai ◽

...

Keyword(s):

Binding Sites ◽

Inflammatory Diseases ◽

Inducible Promoter ◽

Transcriptional Factor ◽

Factor Binding ◽

Inflammatory Processes ◽

Nuclear Receptor Family ◽

Specificity Protein ◽

Receptor Family ◽

Pro Inflammatory Cytokines

Abstract Background Glucocorticoids (GCs) have been extensively used as essential modulators in clinical infectious and inflammatory diseases. The GC receptor (GR) is a transcription factor belonging to the nuclear receptor family that regulates anti-inflammatory processes and releases pro-inflammatory cytokines, such as interleukin (IL)-6. Results Five putative GR binding sites and other transcriptional factor binding sites were identified on theIL-6 promoter, and dexamethasone (DEX) was noted to reduce the lipopolysaccharide (LPS)-induced IL-6 production. Among mutant transcriptional factor binding sites, nuclear factor-kappa B (NF-κB), activator protein (AP)-1, and specificity protein (Sp)1–2 sites reduced basal and LPS-induced IL-6 promoter activities through various responses. The second GR binding site (GR2) was noted to play a crucial role in both basal and inducible promoter activities in LPS-induced inflammation. Conclusions We concluded that selective GR2 modulator might exert agonistic and antagonistic effects and could activate crucial signaling pathways during the LPS-stimulated inflammatory process.

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Kyungheechunggan-Tang-01, a New Herbal Medication, Suppresses LPS-Induced Inflammatory Responses through JAK/STAT Signaling Pathway in RAW 264.7 Macrophages

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2017/7383104 ◽

2017 ◽

Vol 2017 ◽

pp. 1-15 ◽

Cited By ~ 4

Author(s):

Hee-Soo Han ◽

Eungyeong Jang ◽

Ji-Sun Shin ◽

Kyung-Soo Inn ◽

Jang-Hoon Lee ◽

...

Keyword(s):

Signaling Pathway ◽

Inflammatory Responses ◽

Inflammatory Diseases ◽

Molecular Data ◽

Mrna Levels ◽

Protein Levels ◽

Stat3 Phosphorylation ◽

Stat Signaling ◽

Cox 2 ◽

Anti Inflammatory

Medicinal plants have been used as alternative therapeutic tools to alleviate inflammatory diseases. The objective of this study was to evaluate anti-inflammatory properties of Kyungheechunggan-tang- (KCT-) 01, KCT-02, and Injinchunggan-tang (IJCGT) as newly developed decoctions containing 3–11 herbs in LPS-induced macrophages. KCT-01 showed the most potent inhibitory effects on LPS-induced NO, PGE2, TNF-α, and IL-6 production among those three herbal formulas. In addition, KCT-01 significantly inhibited LPS-induced iNOS and COX-2 at protein levels and expression of iNOS, COX-2, TNF-α, and IL-6 at mRNA levels. Molecular data revealed that KCT-01 attenuated the activation of JAK/STAT signaling cascade without affecting NF-κB or AP-1 activation. In ear inflammation induced by croton oil, KCT-01 significantly reduced edema, MPO activity, expression levels of iNOS and COX-2, and STAT3 phosphorylation in ear tissues. Taken together, our findings suggest that KCT-01 can downregulate the expression of proinflammatory genes by inhibiting JAK/STAT signaling pathway under inflammatory conditions. This study provides useful data for further exploration and application of KCT-01 as a potential anti-inflammatory medicine.

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