Pro-inflammatory cytokines reduce human TAFI expression via tristetraprolin-mediated mRNA destabilisation and decreased binding of HuR

2015 ◽  
Vol 114 (08) ◽  
pp. 337-349 ◽  
Author(s):  
Dragana Komnenov ◽  
Corey Scipione ◽  
Zainab Bazzi ◽  
Justin Garabon ◽  
Marlys Koschinsky ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Inflammatory Mediators ◽  
Hepg2 Cells ◽  
Inflammatory Cells ◽  
Gene Encoding ◽  
Protein Levels ◽  
Anti Inflammatory ◽  
Mechanistic Basis ◽  
Pro Inflammatory Cytokines

SummaryThrombin activatable fibrinolysis inhibitor (TAFI) is the zymogen form of a basic carboxypeptidase (TAFIa) with both anti-fibrinolytic and anti-inflammatory properties. The role of TAFI in inflammatory disease is multifaceted and involves modulation both of specific inflammatory mediators as well as of the behaviour of inflammatory cells. Moreover, as suggested by in vitro studies, inflammatory mediators are capable of regulating the expression of CPB2, the gene encoding TAFI. In this study we addressed the hypothesis that decreased TAFI levels observed in inflammation are due to post-transcriptional mechanisms. Treatment of human HepG2 cells with pro-inflammatory cytokines TNFα, IL-6 in combination with IL-1β, or with bacterial lipopolysaccharide (LPS) decreased TAFI protein levels by approximately two-fold over 24 to 48 hours of treatment. Conversely, treatment of HepG2 cells with the anti-inflammatory cytokine IL-10 increased TAFI protein levels by two-fold at both time points. We found that the mechanistic basis for this modulation of TAFI levels involves binding of tristetraprolin (TTP) to the CPB2 3′-UTR, which mediates CPB2 mRNA destabilisation. In this report we also identified that HuR, another ARE-binding protein but one that stabilises transcripts, is capable of binding the CBP2 3’UTR. We found that pro-inflammatory mediators reduce the occupancy of HuR on the CPB2 3’-UTR and that the mutation of the TTP binding site in this context abolishes this effect, although TTP and HuR appear to contact discrete binding sites. Interestingly, all of the mediators tested appear to increase TAFI protein expression in THP-1 macrophages, likewise through effects on CPB2 mRNA stability.

AAnti-Inflammatory Effects of Plasma Circulating Exosomes Obtained from Normal-Weight and Obese Subjects on Hepatocytes

2020 ◽  
Vol 20 ◽  
Author(s):  
Reza Afrisham ◽  
Sahar Sadegh-Nejadi ◽  
Reza Meshkani ◽  
Solaleh Emamgholipour ◽  
Molood Bagherieh ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Hepg2 Cells ◽  
Human Liver ◽  
Liver Cells ◽  
Normal Weight ◽  
Protein Levels ◽  
Human Liver Cells ◽  
Tnf Α ◽  
Anti Inflammatory

Introduction: Obesity is a disorder with low-grade chronic inflammation that plays a key role in the hepatic inflammation and steatosis. Moreover, there are studies to support the role of exosomes in the cellular communications, the regulation of metabolic homeostasis and immunomodulatory activity. Accordingly, we aimed to evaluate the influence of plasma circulating exosomes derived from females with normal-weight and obesity on the secretion of inflammatory cytokines in human liver cells. Methods: Plasma circulating exosomes were isolated from four normal (N-Exo) and four obese (O-Exo) women. The exosomes were characterized and approved for CD63 expression (common exosomal protein marker) and morphology/size using the western blot and TEM methods, respectively. The exosomes were used for stimulation of HepG2 cells in vitro. After 24 h incubation, the protein levels of TNF-α,IL-6, and IL-1β were measured in the culture supernatant of HepG2 cells using the ELISA kit. Results: The protein levels of IL-6 and TNF-α in the cells treated with O-Exo and N-Exo reduced significantly in comparison with control group (P=0.039 and P<0.001 respectively), while significance differences were not found between normal and obese groups (P=0.808, and P=0.978 respectively). However, no significant differences were found between three groups in term of IL-1β levels (P=0.069). Based on the correlation analysis, the protein levels of IL-6 were positively correlated with TNF-α (r 0.978, P<0.001). Conclusion: These findings suggest that plasma circulating exosomes have probably anti-inflammatory properties independently from body mass index and may decrease the secretion of inflammatory cytokines in liver. However, further investigations in vitro and in vivo are needed to address the anti-inflammatory function of N-Exo and O-Exo in human liver cells and/or other cells.

Abstract 582: Inflammatory Cytokines Reduce Thrombin Activatable Fibrinolysis Inhibitor Protein Levels in HepG2 Cells via TTP-Mediated Destabilization of TAFI mRNA

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Dragana Novakovic ◽  
Michael B Boffa
Keyword(s):  
Inflammatory Cytokines ◽  
Inflammatory Mediators ◽  
Mrna Stability ◽  
Hepg2 Cells ◽  
Fusion Transcript ◽  
Thrombin Activatable Fibrinolysis Inhibitor ◽  
Protein Levels ◽  
Fibrinolysis Inhibitor ◽  
Anti Inflammatory

Thrombin activatable fibrinolysis inhibitor (TAFI) is the zymogen form of a basic carboxypeptidase (TAFIa) with both anti-fibrinolytic and anti-inflammatory properties. The role of TAFI in inflammatory disease is multifaceted and involves both recognition of specific pro-inflammatory substrates by TAFIa as well as regulation of TAFI gene expression by inflammatory mediators. In this study we addressed the hypothesis that decreased TAFI levels observed in inflammation are due to destabilization of its mRNA via the A/U-rich responsive element binding protein tristetraprolin (TTP). TAFI protein levels were measured in conditioned medium of HepG2 cells with recently developed assay specific for TAFIa. Treatment of cells with pro-inflammatory cytokines TNFα, IL-6 in combination with IL-1β, or with bacterial lipopolysaccharide (LPS) decreased TAFI protein levels by approximately 2-fold over 24 to 48 hours of treatment. Conversely, treatment of HepG2 cells with the anti-inflammatory cytokine IL-10 increased TAFI protein levels by 2-fold at both 24 and 48 hour time points. We employed luciferase reporter gene studies using human TAFI promoter constructs and found no change in promoter activity with these treatments. We then hypothesized that changes in mRNA stability may be involved through binding of TTP to the TAFI 3’-UTR, as we recently characterized the role of TTP in mediating TAFI mRNA stability. Using constructs expressing β-globin fusion mRNAs containing the TAFI 3’-UTR, we found that TNFα, IL-6, IL-1β, and LPS reduce TAFI mRNA half-life by 30%. This effect appears to be dependent on TTP binding, since these cytokines did not alter the stability of a fusion transcript lacking the TTP binding site. IL-10 caused an increase in fusion transcript stability by 38%, an effect that was also observed when the TTP binding site was mutated. Using reporter constructs expressing fusion mRNA’s containing the luciferase coding region and the TAFI 3’-UTR, we found that translation rate remained unaffected with both pro- and anti-inflammatory treatments. In conclusion, destabilization of TAFI mRNA appears to be the main mechanism behind decreased TAFI protein levels observed in the presence of pro-inflammatory mediators.

scholarly journals Cerebrospinal fluid biomarkers of neuroinflammation in children with hydrocephalus and shunt malfunction

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Carolyn A. Harris ◽  
Diego M. Morales ◽  
Rooshan Arshad ◽  
James P. McAllister ◽  
David D. Limbrick
Keyword(s):  
Cerebrospinal Fluid ◽  
Inflammatory Cytokines ◽  
Protein Concentration ◽  
Shunt Revision ◽  
Csf Shunt ◽  
Shunt Failure ◽  
Revision Operation ◽  
Protein Levels ◽  
Anti Inflammatory ◽  
Pro Inflammatory Cytokines

Abstract Background Approximately 30% of cerebrospinal fluid (CSF) shunt systems for hydrocephalus fail within the first year and 98% of all patients will have shunt failure in their lifetime. Obstruction remains the most common reason for shunt failure. Previous evidence suggests elevated pro-inflammatory cytokines in CSF are associated with worsening clinical outcomes in neuroinflammatory diseases. The aim of this study was to determine whether cytokines and matrix metalloproteinases (MMPs) contribute towards shunt failure in hydrocephalus. Methods Using multiplex ELISA, this study examined shunt failure through the CSF protein concentration profiles of select pro-inflammatory and anti-inflammatory cytokines, as well as select MMPs. Interdependencies such as the past number of previous revisions, length of time implanted, patient age, and obstruction or non-obstruction revision were examined. The pro-inflammatory cytokines were IL-1β, IL-2, IL-5, IL-6, IL-8, IL-12, IL-17, TNF-α, GM-CSF, IFN-γ. The anti-inflammatory cytokines were IL-4 and IL-10, and the MMPs were MMP-2, MMP-3, MMP-7, MMP-9. Protein concentration is reported as pg/mL for each analyte. Results Patient CSF was obtained at the time of shunt revision operation; all pediatric (< 18), totaling n = 38. IL-10, IL-6, IL-8 and MMP-7 demonstrated significantly increased concentrations in patient CSF for the non-obstructed subgroup. Etiological examination revealed IL-6 was increased in both obstructed and non-obstructed cases for PHH and congenital hydrocephalic patients, while IL-8 was higher only in PHH patients. In terms of number of past revisions, IL-10, IL-6, IL-8, MMP-7 and MMP-9 progressively increased from zero to two past revisions and then remained low for subsequent revisions. This presentation was notably absent in the obstruction subgroup. Shunts implanted for three months or less showed significantly increased concentrations of IL-6, IL-8, and MMP-7 in the obstruction subgroup. Lastly, only patients aged six months or less presented with significantly increased concentration of IL-8 and MMP-7. Conclusion Non-obstructive cases are reported here to accompany significantly higher CSF cytokine and MMP protein levels compared to obstructive cases for IL-10, IL-6, IL-8, MMP-7 and MMP-9. A closer examination of the definition of obstruction and the role neuroinflammation plays in creating shunt obstruction in hydrocephalic patients is suggested.

The protective effects of carvacrol and thymol against paracetamol–induced toxicity on human hepatocellular carcinoma cell lines (HepG2)

2016 ◽  
Vol 35 (12) ◽  
pp. 1252-1263 ◽  
Author(s):  
SS Palabiyik ◽  
E Karakus ◽  
Z Halici ◽  
E Cadirci ◽  
Y Bayir ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Inflammatory Cytokines ◽  
Hepg2 Cells ◽  
Folk Medicine ◽  
Hepatoprotective Activity ◽  
High Dose ◽  
Protective Effects ◽  
And Oxidative Stress ◽  
Pro Inflammatory Cytokines

Acetaminophen (APAP) overdose could induce liver damage and lead to acute liver failure. The treatment of APAP overdoses could be improved by new therapeutic strategies. Thymus spp., which has many beneficial effects and has been used in folk medicine, is one such potential strategy. In the present study, the hepatoprotective activity of the main constituents of Thymus spp., carvacrol and thymol, were evaluated in light of APAP-induced hepatotoxicity. We hoped to understand the hepatoprotective mechanism of these agents on the antioxidant system and pro-inflammatory cytokines in vitro. Dose-dependent effects of thymol and carvacrol (25, 50, and 100 µM) were tested on cultured HepG2 cells. N-Acetylcysteine (NAC) was tested as positive control. We showed that APAP inhibited HepG2 cell growth by inducing inflammation and oxidative stress. Incubating APAP-exposed HepG2 cells with carvacrol and thymol for 24 h ameliorated this inflammation and oxidative stress. We also evaluated alanine transaminase and lactate dehydrogenase levels of HepG2 cells. We found that thymol and carvacrol protected against APAP-induced toxicity in HepG2 cells by increasing antioxidant activity and reducing pro-inflammatory cytokines, such as tumor necrosis factor α and interleukin 1β. Taking together high-dose thymol and carvacrol treatment has an effect close to NAC treatment in APAP toxicity, but thymol has better treatment effect than carvacrol.

Artemisinin improves neurocognitive deficits associated with sepsis by activating the AMPK axis in the microglia.

2020 ◽  
Author(s):  
Shao-Peng Lin ◽  
Jue-Xian Wei ◽  
Shan Ye ◽  
Jiasong Hu ◽  
Jingyi Bu ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Inflammatory Cytokines ◽  
Nuclear Translocation ◽  
Neuronal Damage ◽  
Protective Mechanism ◽  
Protective Effects ◽  
Neurocognitive Deficits ◽  
Anti Inflammatory ◽  
Pro Inflammatory Cytokines

Abstract Background and purpose: Artemisinin has been in use as an anti-malarial drug for almost half a century in the world. There is growing evidence that artemisinin also possesses potent anti-inflammatory and immunoregulatory properties. However, the efficacy of artemisinin treatment in neurocognitive deficits associated with sepsis remains unknown. Here, we evaluate the possible protective effects and explore the underlying mechanism of artemisinin on cognitive impairment resulting from sepsis.Methods: Male C57BL/6 mice were pretreated with either vehicle or artemisinin, and then injected with LPS to establish an animal model of sepsis. The cognitive function was then assessed using the Morris water maze. Neuronal damage and neuroinflammation in the hippocampus were evaluated by immunohistochemical and ELISA analysis. Additionally, the protective mechanism of artemisinin was determined in vitro.Results: The results showed that artemisinin preconditioning attenuated LPS-induced cognitive impairment, neural damage, and microglial activation in the mouse brain. The in vitro experiment revealed that artemisinin could reduce the production of pro-inflammatory cytokines and suppress the microglial migration in the BV2 microglia cells. Meanwhile, western blot demonstrated that artemisinin suppressed nuclear translocation of nuclear factor kappa-B and the expression of pro-inflammatory cytokines (i.e. tumor necrosis factor alpha, interleukin-6) by activating adenosine monophosphate-activated protein kinaseα1 (AMPKα1) pathway. Furthermore, knock-down of AMPKα1 markedly abolished the anti-inflammatory effects of artemisinin.Conclusion: Artemisinin is a potential therapeutic agent for sepsis-associated neuroinflammation and cognitive impairment, and its effect was probably mediated by the activation of AMPKα1 signalling pathway in microglia.

scholarly journals P0527AROLE OF PROMOTING INFLAMMATION OF KLF6 IN ACUTE KIDNEY INURY

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Dan Li ◽  
Chenyu Li ◽  
Yan Xu
Keyword(s):  
Inflammatory Cytokines ◽  
Inflammatory Cytokine ◽  
Ischemia Reperfusion ◽  
Kidney Injury ◽  
Tnf Α ◽  
Public Dataset ◽  
Anti Inflammatory ◽  
Anti Inflammatory Cytokine ◽  
Pro Inflammatory Cytokines

Abstract Background and Aims Acute kidney injury (AKI), commonly appeared in cardiac arrest, surgery and kidney transplantation which involved in ischemia-reperfusion (IR) injury of kidney. However, the mechanisms underlying inflammatory response in IR AKI is still unclear. Method Public dataset showed kruppel-like factor 6 (KLF6) was significantly highly expressed (P&lt;0.05) in AKI, implies KLF6 might be associated with AKI. To evaluate the mechanism of KLF6 on IR AKI, 30 rats were randomly divided into sham and IR group, and were sacrificed at 0 h, 3 h, 6 h, 12 h or 24 h after IR. Results The results showed KLF6 expression was peaking at 6 h after IR, and the expression of pro-inflammatory cytokines MCP-1 and TNF-α were increased both in serum and kidney tissues after IR, while anti-inflammatory cytokine IL-10 was decreased after IR. Furthermore, in vitro results showed KLF6 knock-down reduced the pro-inflammatory cytokines expression and increased the anti-inflammatory cytokines expression. Conclusion These results suggest that (1) KLF6 might be a novel biomarker for early diagnosis of AKI and (2) targeting KLF6 expression may offer novel strategies to protect kidneys from IR AKI Figure KLF6, AKI, Control Inflammation

scholarly journals Astilbe Chinensis ethanol extract suppresses inflammation in macrophages via NF-κB pathway

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Tae-Young Gil ◽  
Bo-Ram Jin ◽  
Chul-Hee Hong ◽  
Jong Hyuk Park ◽  
Hyo-Jin An
Keyword(s):  
Nitric Oxide ◽  
Inflammatory Cytokines ◽  
Inflammatory Mediators ◽  
Ethanol Extract ◽  
Nuclear Factor Κb ◽  
Peritoneal Macrophages ◽  
Necrosis Factor Alpha ◽  
Iκb Kinase ◽  
Anti Inflammatory ◽  
Pro Inflammatory Cytokines

Abstract Background Macrophages play a crucial role in inflammation. Astilbe chinensis is one of perennial herbs belonging to the genus Astilbe. Plants in the genus have been used for pain, headaches, arthralgia, and chronic bronchitis. However, the effect of A.chinensis on inflammation remains unclear. To study the anti-inflammatory action of A.chinensis ethanol extract (ACE), we investigated the effect of ACE on the production of pro-inflammatory mediators and cytokines in macrophages. Methods We evaluated the effectiveness of ACE in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and thioglycollate (TG)-elicited peritoneal macrophages from male C57BL/6 mice. We measured the levels of pro-inflammatory mediators and cytokines, and examined the anti-inflammatory actions of ACE on nuclear factor κB (NF-κB) pathway in the macrophages. Western blot analysis and immunofluorescence microscopy were used to determine protein level and translocation, respectively. Results ACE suppressed the output of nitric oxide (NO), prostaglandin E2 (PGE2), and pro-inflammatory cytokines in stimulated macrophages via inhibiting the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins. ACE suppressed mRNA expression of pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-α). We examined the efficacies of ACE on NF-κB activation by measuring the expressions including IκB kinase (IKK), inhibitor of κB (IκB), and nuclear p65 proteins. In addition, the inhibition of NF-κB p65’s translocation was determined with immunofluorescence assay. Conclusion Our findings manifested that ACE inhibited LPS or TG-induced inflammation by blocking the NF-κB signaling pathway in macrophages. It indicated that ACE is a potential therapeutic mean for inflammation and related diseases.

scholarly journals Extracellular vesicles from human cardiovascular progenitors trigger a reparative immune response in infarcted hearts

2020 ◽  
Author(s):  
Bruna Lima Correa ◽  
Nadia El Harane ◽  
Ingrid Gomez ◽  
Hocine Rachid Hocine ◽  
José Vilar ◽  
...  
Keyword(s):  
Immune Response ◽  
Extracellular Vesicles ◽  
Inflammatory Cytokines ◽  
Nk Cell ◽  
Inflammatory Monocytes ◽  
Ifn Γ ◽  
Anti Inflammatory ◽  
Pro Inflammatory Cytokines

Abstract Aims The cardioprotective effects of human induced pluripotent stem cell-derived cardiovascular progenitor cells (CPC) are largely mediated by the paracrine release of extracellular vesicles (EV). We aimed to assess the immunological behaviour of EV-CPC, which is a prerequisite for their clinical translation. Methods and results Flow cytometry demonstrated that EV-CPC expressed very low levels of immune relevant molecules including HLA Class I, CD80, CD274 (PD-L1), and CD275 (ICOS-L); and moderate levels of ligands of the natural killer (NK) cell activating receptor, NKG2D. In mixed lymphocyte reactions, EV-CPC neither induced nor modulated adaptive allogeneic T cell immune responses. They also failed to induce NK cell degranulation, even at high concentrations. These in vitro effects were confirmed in vivo as repeated injections of EV-CPC did not stimulate production of immunoglobulins or affect the interferon (IFN)-γ responses from primed splenocytes. In a mouse model of chronic heart failure, intra-myocardial injections of EV-CPC, 3 weeks after myocardial infarction, decreased both the number of cardiac pro-inflammatory Ly6Chigh monocytes and circulating levels of pro-inflammatory cytokines (IL-1α, TNF-α, and IFN-γ). In a model of acute infarction, direct cardiac injection of EV-CPC 2 days after infarction reduced pro-inflammatory macrophages, Ly6Chigh monocytes, and neutrophils in heart tissue as compared to controls. EV-CPC also reduced levels of pro-inflammatory cytokines IL-1α, IL-2, and IL-6, and increased levels of the anti-inflammatory cytokine IL-10. These effects on human macrophages and monocytes were reproduced in vitro; EV-CPC reduced the number of pro-inflammatory monocytes and M1 macrophages, while increasing the number of anti-inflammatory M2 macrophages. Conclusions EV-CPC do not trigger an immune response either in in vitro human allogeneic models or in immunocompetent animal models. The capacity for orienting the response of monocyte/macrophages towards resolution of inflammation strengthens the clinical attractiveness of EV-CPC as an acellular therapy for cardiac repair.

scholarly journals Estrogen receptor α phosphorylated at Ser216 confers inflammatory function to mouse microglia

2019 ◽  
Author(s):  
Sawako Shindo ◽  
Shih-Heng Chen ◽  
Saki Gotoh ◽  
Kosuke Yokobori ◽  
Hao Hu ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Inflammatory Cytokines ◽  
Estrogen Receptor Α ◽  
Microglia Activation ◽  
Immune Functions ◽  
Protein Levels ◽  
Brain Extracts ◽  
Anti Inflammatory ◽  
The Brain ◽  
Pro Inflammatory Cytokines

Abstract Background Estrogen has been suggested to regulate anti-inflammatory signaling in brain microglia through estrogen receptor α (ERα), the only resident immune cells of the brain. The mechanism of how ERα regulates is not well understood. Previously, ERα is phosphorylated at Ser216 in mouse neutrophils, regulating their infiltration into the uterus. Therefore, ERα has now been examined as to its phosphorylation in microglia to regulate their inflammatory functions.MethodsAn antibody against an anti-phospho-S216 peptide of ERα (αP-S216) was used for double immunofluorescence staining to detect to ERα in cultured microglia. A knock-in (KI) mouse line bearing the phosphorylation-blocked ERα mutation S216A (ERα KI) was generated to examine whether this phosphorylation regulate immune functions of microglia.ResultsPhosphorylated ERα at Ser216 was present in microglia but not astrocytes. Staining with an anti-Iba-1 antibody showed that microglia activation was augmented in substantial nigra of ERα KI brains. Lipopolysaccharide (LPS) treatments aggravated microglia activation in ERα KI brains, pro-inflammatory cytokines were increased while anti-inflammatory cytokines were decreased at mRNA and protein levels in whole brain extracts. These increases and decreases of cytokine proteins were also observed in LPS-treated microglia cultured from brains of ERα KI neonates. FACS analysis revealed that ERα KI mutation increased number of IL-6 producing microglia and apoptosis. ERα KI mice decreased motor connection ability in Rotarod tests.ConclusionsBlocking of Ser216 phosphorylation aggravated microglia activation and inflammation of mouse brain, thus confirming that phosphorylated ERα exerts anti-inflammatory functions. ERα KI mice enable us to further investigate the mechanism by which phosphorylated ERα regulates brain immunity and inflammation.

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