scholarly journals Novel interaction of antioxidant-1 with TRAF4: role in inflammatory responses in endothelial cells

2019 ◽  
Vol 317 (6) ◽  
pp. C1161-C1171
Author(s):  
Archita Das ◽  
Varadarajan Sudhahar ◽  
Masuko Ushio-Fukai ◽  
Tohru Fukai

NADPH oxidase (NOX)-derived reactive oxygen species (ROS) and copper (Cu), an essential micronutrient, have been implicated in vascular inflammatory diseases. We reported that in proinflammatory cytokine TNF-α-stimulated endothelial cells (ECs), cytosolic Cu chaperone antioxidant-1 (Atox1) functions as a Cu-dependent transcription factor for the NOX organizer p47phox, thereby increasing ROS-dependent inflammatory gene expression. However, the role and mechanism of Atox1 nuclear translocation in inflamed ECs remain unclear. Using enface staining and nuclear fractionation, here we show that Atox1 was localized in the nucleus in inflamed aortas from ApoE−/− mice with angiotensin II infusion on a high-fat diet, while it was found in cytosol in those from control mice. In cultured human ECs, TNF-α stimulation promoted Atox1 nuclear translocation within 15 min, which was associated with Atox1 binding to TNF-α receptor-associated factor 4 (TRAF4) in a Cu-dependent manner. TRAF4 depletion by siRNA significantly inhibited Atox1 nuclear translocation, p47phox expression, and ROS production as well as its downstream VCAM1/ICAM1 expression and monocyte adhesion to inflamed ECs, which were rescued by overexpression of nuclear targeted Atox1. Furthermore, Atox1 colocalized with TRAF4 at the nucleus in TNF-α-stimulated inflamed ECs and vessels. In summary, Cu-dependent Atox1 binding to TRAF4 plays an important role in Atox1 nuclear translocation and ROS-dependent inflammatory responses in TNF-α-stimulated ECs. Thus the Atox1-TRAF4 axis is a novel therapeutic target for vascular inflammatory disease such as atherosclerosis.

2019 ◽  
Author(s):  
Sanoji Wijenayake ◽  
Mouly F. Rahman ◽  
Christine M.W. Lum ◽  
Wilfred C. De Vega ◽  
Aya Sasaki ◽  
...  

ABSTRACTBackgroundAcute elevations in endogenous corticosterone (CORT) with psychosocial stress or exogenous administration potentiate inflammatory gene expression. Maternal obesity as a result of high-fat diet (HFD) consumption has been linked to higher basal levels of neuroinflammation, including increased expression of pro-inflammatory genes in the amygdala. These findings suggest that exposure to maternal HFD may elicit pro-inflammatory responses in the presence of an immune stressor such as lipopolysaccharide (LPS), a component of gram-negative bacteria, as well as acute elevated CORT.MethodsRat offspring were exposed to maternal HFD or control diet (CHD) throughout pre and postnatal development until weaning, when all offspring were provided CHD until adulthood. In adulthood, offspring were ‘challenged’ with administration of exogenous CORT, to simulate an acute physiological stress, LPS, to induce an immune stress, or both. qPCR was used to measure transcript abundance of CORT receptors and downstream inflammatory genes in the amygdala, hippocampus and prefrontal cortex, brain regions that mediate neuroendocrine and behavioral responses to stress.ResultsHFD female offspring exhibited elevations in anti-inflammatory transcripts, whereas HFD male offspring responded with greater pro-inflammatory gene expression to simultaneous CORT and LPS administration.ConclusionsThese findings suggest that exposure to maternal HFD leads to sex-specific alterations that may alter inflammatory responses in the brain, possibly as an adaptive response to basal inflammation.


2020 ◽  
Author(s):  
Yalei Zhang ◽  
Xiaobing Deng ◽  
Hao Liang ◽  
Annan Guo ◽  
Kenan Li ◽  
...  

Abstract Background: Dimethyl itaconate (DMI), a membrane-permeable derivative of itaconate, was found to moderate IL-17-IκBζ-induced skin pathology including psoriasis in mouse experiments . TNF-α induced NF-κB pathway, which controls a variety of immune and inflammatory responses, was also proven to play a crucial role as mediator in psoriasis. However, whether DMI interacts with the TNF-α induced NF-κB pathway remains unclear. Results: Here we show that DMI inhibits TNF-α induced NF-κB transcriptional activities in dose-dependent manner in several human cell lines using dual luciferase assay and blocks the NF-κB nuclear entry. Moreover, DMI potently inhibits IKKβ dependent phosphorylation and degradation of IκBα in TNF-α induced activation of NF-κB pathway. We also demonstrate that DMI covalently binds to cysteine residue in IKKβ, a key regulator in NF-κB pathway, to suppress IKKβ activation and inhibit the canonical NF-κB pathway. Conclusion Our study presents a new mechanism for DMI as an anti-inflammatory agent that may have therapeutic potentials in treating NF-κB related human inflammatory diseases. Our results also suggest that itaconate produced by endogenous IRG1 may regulate NF-κB at post translation modification level, and the IRG1-itaconate-NF-κB axis could be targeted as a novel strategy for the treatment of IRG1-NF-κB mediated diseases.


2021 ◽  
Vol 23 (1) ◽  
pp. 221
Author(s):  
Vanesa Palau ◽  
Josué Jarrín ◽  
Sofia Villanueva ◽  
David Benito ◽  
Eva Márquez ◽  
...  

Disintegrin and metalloproteinase domain 17 (ADAM17) activates inflammatory and fibrotic processes through the shedding of various molecules such as Tumor Necrosis Factor-α (TNF-α) or Transforming Growht Factor-α (TGF-α). There is a well-recognised link between TNF-α, obesity, inflammation, and diabetes. In physiological situations, ADAM17 is expressed mainly in the distal tubular cell while, in renal damage, its expression increases throughout the kidney including the endothelium. The aim of this study was to characterize, for the first time, an experimental mouse model fed a high-fat diet (HFD) with a specific deletion of Adam17 in endothelial cells and to analyse the effects on different renal structures. Endothelial Adam17 knockout male mice and their controls were fed a high-fat diet, to induce obesity, or standard rodent chow, for 22 weeks. Glucose tolerance, urinary albumin-to-creatinine ratio, renal histology, macrophage infiltration, and galectin-3 levels were evaluated. Results showed that obese mice presented higher blood glucose levels, dysregulated glucose homeostasis, and higher body weight compared to control mice. In addition, obese wild-type mice presented an increased albumin-to-creatinine ratio; greater glomerular size and mesangial matrix expansion; and tubular fibrosis with increased galectin-3 expression. Adam17 deletion decreased the albumin-to-creatinine ratio, glomerular mesangial index, and tubular galectin-3 expression. Moreover, macrophage infiltration in the glomeruli of obese Adam17 knockout mice was reduced as compared to obese wild-type mice. In conclusion, the expression of ADAM17 in endothelial cells impacted renal inflammation, modulating the renal function and histology in an obese pre-diabetic mouse model.


2017 ◽  
Vol 95 (5) ◽  
pp. 481-491 ◽  
Author(s):  
Changyu Ding ◽  
Fangfang Li ◽  
Yupeng Long ◽  
Jiang Zheng

Lipopolysaccharide (LPS) is a key pathogenic factor in sepsis, and its recognition by toll-like receptor 4 (TLR4) can activate two district signaling pathways, leading to activation of transcription factors including NF-κB and interferon regulatory factor 3 (IRF3). Chloroquine (CQ) has been shown to affect LPS–TLR4 colocalization and inhibit both MyD88-dependent and TRAM/TRIF-dependent pathways, though the mechanism involved is still poorly understood. Here, we found that the ubiquitin–proteasome system might be involved in this process. CQ increased USP25, a deubiquitinating enzyme, as well as mRNA and protein expression in a dose-dependent manner, which might to some degree be involved in CQ attenuation of LPS-induced macrophage activation. Overexpression of USP25 decreased LPS-induced inflammatory cytokines like TNF-α, IL-6, and IFN-β, while specific siRNA-mediated USP25 silencing increased TNF-α, IL-6, and IFN-β production and secretion. In addition, USP25 deletion strengthened mitogen-activated protein kinase (MAPKs) phosphorylation and IκB degradation. Moreover, USP25 interference increased NF-κB and IRF3 nuclear translocation. Taken together, our data demonstrated a new possible regulator of LPS-induced macrophage activation mediated by CQ, through upregulation of USP25.


2006 ◽  
Vol 290 (5) ◽  
pp. H1862-H1870 ◽  
Author(s):  
Xi-Lin Chen ◽  
Geraldine Dodd ◽  
Suzanne Thomas ◽  
Xiaolan Zhang ◽  
Martin A. Wasserman ◽  
...  

The antioxidant response element (ARE) is a transcriptional control element that mediates expression of a set of antioxidant proteins. NF-E2-related factor 2 (Nrf2) is a transcription factor that activates ARE-containing genes. In endothelial cells, the ARE-mediated genes are upregulated by atheroprotective laminar flow through a Nrf2-dependent mechanism. We tested the hypothesis that activation of ARE-regulated genes via adenovirus-mediated expression of Nrf2 may suppress redox-sensitive inflammatory gene expression. Expression of Nrf2 in human aortic endothelial cells (HAECs) resulted in a marked increase in ARE-driven transcriptional activity and protected HAECs from H2O2-mediated cytotoxicity. Nrf2 suppressed TNF-α-induced monocyte chemoattractant protein (MCP)-1 and VCAM-1 mRNA and protein expression in a dose-dependent manner and inhibited TNF-α-induced monocytic U937 cell adhesion to HAECs. Nrf2 also inhibited IL-1β-induced MCP-1 gene expression in human mesangial cells. Expression of Nrf2 inhibited TNF-α-induced activation of p38 MAP kinase. Furthermore, expression of a constitutively active form of MKK6 (an upstream kinase for p38 MAP kinase) partially reversed Nrf2-mediated inhibition of VCAM-1 expression, suggesting that p38 MAP kinase, at least in part, mediates Nrf2's anti-inflammatory action. In contrast, Nrf2 did not inhibit TNF-α-induced NF-κB activation. These data identify the Nrf2/ARE pathway as an endogenous atheroprotective system for antioxidant protection and suppression of redox-sensitive inflammatory genes, suggesting that targeting the Nrf2/ARE pathway may represent a novel therapeutic approach for the treatment of inflammatory diseases such as atherosclerosis.


2019 ◽  
Author(s):  
yalei zhang ◽  
Xiaobing Deng ◽  
Hao Liang ◽  
Kenan Li ◽  
Annan Guo ◽  
...  

Abstract Background: Dimethyl itaconate (DMI), a membrane-permeable derivative of itaconate, was found to moderate IL-17-IκBζ-induced skin pathology including psoriasis in mouse experiments. TNF-α induced NF-κB pathway, which controls a variety of immune and inflammatory responses, was also proven to play a crucial role as mediator in psoriasis. However, whether DMI interacts with the TNF-α induced NF-κB pathway remains unclear. Results: Here we show that DMI inhibits TNF-α induced NF-κB transcriptional activities in dose-dependent manner in several human cell lines using dual luciferase assay and blocks the NF-κB nuclear entry. Moreover, DMI potently inhibits IKKβ dependent phosphorylation and degradation of IκBα in TNF-α induced activation of NF-κB pathway. We also demonstrate that DMI covalently binds to cysteine residue in IKKβ, a key regulator in NF-κB pathway, to suppress IKKβ activation and inhibit the canonical NF-κB pathway. Conclusion Our study presents a new mechanism for DMI as an anti-inflammatory agent that may have therapeutic potentials in treating NF-κB related human inflammatory diseases. Our results also suggest that itaconate produced by endogenous IRG1 may regulate NF-κB at post translation modification level, and the IRG1-itaconate-NF-κB axis could be targeted as a novel strategy for the treatment of IRG1-NF-κB mediated diseases.


Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2795
Author(s):  
Yun Jung Lee ◽  
Yong Pyo Lee ◽  
Chang Seob Seo ◽  
Eun Sik Choi ◽  
Byung Hyuk Han ◽  
...  

Carthamus tinctorius L., known as safflower, has been used in traditional treatment for cardiovascular, cerebrovascular, and diabetic vascular complications. We proposed to investigate how the ethanol extract of Carthamus tinctorius L. (ECT) can be used ethnopharmacologically and alleviate vascular inflammatory processes under cytokine stimulation in human vascular endothelial cells. Using the optimized HPLC method, six markers were simultaneously analyzed for quality control of ECT. Pretreatment with ECT (10–100 μg/mL) significantly reduced the increase of leukocyte adhesion to HUVEC by TNF-α in a dose-dependent manner. Cell adhesion molecules (CAMs) such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial cell selectin (E-selectin) are decreased by ECT. In addition, ECT significantly suppressed TNF-α-induced oxidative stress referring to reactive oxygen species (ROS) production. p65 NF-κB nuclear translocation and its activation were inhibited by ECT. Furthermore, pretreatment of ECT increased the HO-1 expression, and nuclear translocation of Nrf-2. These data suggest the potential role of ECT as a beneficial therapeutic herb in vascular inflammation via ROS/NF-kB pathway and the regulation of Nrf-2/HO-1 signaling axis is involved in its vascular protection. Thus, further study will be needed to clarify which compound is dominant for protection of vascular diseases.


2011 ◽  
Vol 300 (2) ◽  
pp. C256-C265 ◽  
Author(s):  
Shyamali Basuroy ◽  
Dilyara Tcheranova ◽  
Sujoy Bhattacharya ◽  
Charles W. Leffler ◽  
Helena Parfenova

We investigated the role of reactive oxygen species (ROS) in promoting cell survival during oxidative stress induced by the inflammatory mediator tumor necrosis factor-α (TNF-α) in cerebral microvascular endothelial cells (CMVEC) from newborn piglets. Nox4 is the major isoform of NADPH oxidase responsible for TNF-α-induced oxidative stress and apoptosis in CMVEC. We present novel data that Nox4 NADPH oxidase-derived ROS also initiate a cell survival mechanism by increasing production of a gaseous antioxidant mediator carbon monoxide (CO) by constitutive heme oxygenase-2 (HO-2). TNF-α rapidly enhanced endogenous CO production in a superoxide- and NADPH oxidase-dependent manner in CMVEC with innate, but not with small interfering RNA (siRNA)-downregulated Nox4 activity. CORM-A1, a CO-releasing compound, inhibited Nox4-mediated ROS production and enhanced cell survival in TNF-α-challenged CMVEC. The ROS-induced CO-mediated survival mechanism requires functional interactions between the protein kinase B/Akt and extracellular signal-related kinase (ERK)/p38 MAPK signaling pathways activated by TNF-α. In Akt siRNA-transfected CMVEC and in cells with pharmacologically inhibited Akt, Erk1/2, and p38 mitogen-activated protein kinase (MAPK) activities, CORM-A1 was no longer capable of blocking Nox4 activation and apoptosis caused by TNF-α. Overall, Nox4 NADPH oxidase-derived ROS initiate both death and survival pathways in TNF-α-challenged CMVEC. The ROS-dependent cell survival pathway is mediated by an endogenous antioxidant CO, which inhibits Nox4 activation via a mechanism that includes Akt, ERK1/2, and p38 MAPK signaling pathways. The ability of CO to inhibit TNF-α-induced ERK1/2 and p38 MAPK activities in an Akt-dependent manner appears to be the key element in ROS-dependent survival of endothelial cells during TNF-α-mediated brain inflammatory disease.


2018 ◽  
Author(s):  
Ingrid Gomez ◽  
Ben Ward ◽  
Celine Souilhol ◽  
Chiara Recarti ◽  
Mark Ariaans ◽  
...  

AbstractNeutrophils have been implicated in the pathogenesis of atherosclerosis, a lipid-driven disease of arteries, but they are seldom found in atherosclerotic plaques. To resolve this longstanding paradox, we investigated whether neutrophil-derived microvesicles may influence arterial pathophysiology. Clinical and pre-clinical studies revealed that levels of circulating neutrophil microvesicles were enhanced by exposure to a high fat diet, a known risk factor for atherosclerosis. Neutrophil microvesicles accumulated at disease-prone regions of arteries that are exposed to complex flow patterns, and they promoted vascular inflammation and atherosclerosis in a murine model. Using cultured endothelial cells exposed to disturbed flow, it was demonstrated that neutrophil microvesicles promoted inflammatory gene expression by delivering a microRNA (miR-155) that enhanced NF-κB activation. Similary, neutrophil microvesicles increased miR-155 and enhanced NF-κB at disease-prone sites of disturbed flow in arteries of mice. We conclude that delivery of microvesicles carrying miR-155 to disease-prone regions of arteries provides a novel mechanism by which neutrophils contribute to vascular inflammation and atherogenesis.


2021 ◽  
Vol 12 ◽  
Author(s):  
Fabiany da Costa Gonçalves ◽  
Sander S. Korevaar ◽  
Maitane Ortiz Virumbrales ◽  
Carla C. Baan ◽  
Marlies E. J. Reinders ◽  
...  

Mesenchymal stromal cells (MSC) are a promising therapy for inflammatory diseases. However, MSC are large and become trapped in the lungs after intravenous infusion, where they have a short survival time. To steer MSC immunoregulatory therapy beyond the lungs, we generated nm-sized particles from MSC membranes (membrane particles, MP), which have immunomodulatory properties, and investigated their internalization and mode of interaction in macrophages subtypes and human umbilical vein endothelial cells (HUVEC) under control and inflammatory conditions. We found that macrophages and HUVEC take up MP in a dose, time, and temperature-dependent manner. Specific inhibitors for endocytotic pathways revealed that MP internalization depends on heparan sulfate proteoglycan-, dynamin-, and clathrin-mediated endocytosis but does not involve caveolin-mediated endocytosis. MP uptake also involved the actin cytoskeleton and phosphoinositide 3-kinase, which are implicated in macropinocytosis and phagocytosis. Anti-inflammatory M2 macrophages take up more MP than pro-inflammatory M1 macrophages. In contrast, inflammatory conditions did not affect the MP uptake by HUVEC. Moreover, MP induced both anti- and pro-inflammatory responses in macrophages and HUVEC by affecting gene expression and cell surface proteins. Our findings on the mechanisms of uptake of MP under different conditions help the development of target-cell specific MP therapy to modulate immune responses.


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