scholarly journals Superoxide, H2O2, and iron are required for TNF-α-induced MCP-1 gene expression in endothelial cells: role of Rac1 and NADPH oxidase

2004 ◽  
Vol 286 (3) ◽  
pp. H1001-H1007 ◽  
Author(s):  
Xi-Lin Chen ◽  
Qiang Zhang ◽  
Ruozhi Zhao ◽  
Russell M. Medford
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Nadph Oxidase ◽  
Gene Activation ◽  
Dominant Negative ◽  
Mrna Levels ◽  
Text Generation ◽  
Mrna Accumulation ◽  
Tnf Α ◽  
Diphenylene Iodonium

Reactive oxygen species (ROS) play an important but not yet fully defined role in the expression of inflammatory genes such as monocyte chemoattractant protein (MCP)-1. We used complementary molecular and biochemical approaches to explore the roles of specific ROS and their molecular linkage to inflammatory signaling in endothelial cells. Adenovirus-mediated expression of superoxide dismutase and catalase inhibited TNF-α-induced MCP-1 gene expression, suggesting important roles of superoxide ([Formula: see text]) and H2O2 in MCP-1 gene activation. In addition, the iron chelator 1,2-dimethyl-3-hydroxypyridin-4-one and the hydroxyl radical scavengers dimethylthiourea and dimethyl sulfoxide inhibited TNF-α-induced MCP-1 expression, suggesting important roles of iron and hydroxyl radicals in inflammatory signal activation. In contrast, scavenging of peroxynitrite with 5,10,15,20-tetrakis-(4-sulfonatophenyl)prophyrinato iron (III) chloride had no effect on TNF-α-induced MCP-1 expression. Inhibition of NADPH oxidase, the major oxidase responsible for [Formula: see text] generation, with diphenylene iodonium suppressed TNF-α-induced MCP-1 mRNA accumulation. Rac1 is an upstream signaling molecule for the activation of NADPH oxidase and [Formula: see text] generation. Expression of dominant negative N17Rac1 by adenovirus suppressed TNF-α-induced MCP-1 mRNA levels and MCP-1 protein secretion. Expression of N17Rac1 inhibited TNF-α-induced MCP-1 and NF-κB transcriptional activity. These data suggest that ROS such as superoxide and H2O2 derived from Rac1-activated NADPH oxidase mediate TNF-α-induced MCP-1 expression in endothelial cells.

Differential effects of NF-κB and p38 MAPK inhibitors and combinations thereof on TNF-α- and IL-1β-induced proinflammatory status of endothelial cells in vitro

2005 ◽  
Vol 289 (5) ◽  
pp. C1229-C1239 ◽  
Author(s):  
Joanna M. Kułdo ◽  
Johanna Westra ◽  
Sigridur A. Ásgeirsdóttir ◽  
Robbert J. Kok ◽  
Koen Oosterhuis ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
P38 Mapk ◽  
Umbilical Vein ◽  
Combined Treatment ◽  
Dominant Negative ◽  
Mrna Levels ◽  
Induced Expression ◽  
Inflammatory Genes ◽  
Tnf Α ◽  
Cox 2

Endothelial cells actively participate in inflammatory events by regulating leukocyte recruitment via the expression of inflammatory genes such as E-selectin, VCAM-1, ICAM-1, IL-6, IL-8, and cyclooxygenase (COX)-2. In this study we showed by real-time RT-PCR that activation of human umbilical vein endothelial cells (HUVEC) by TNF-α and IL-1β differentially affected the expression of these inflammatory genes. Combined treatment with TNF-α and IL-1β resulted in nonadditive, additive, and even synergistic induction of expression of VCAM-1, IL-8, and IL-6, respectively. Overexpression of dominant-negative inhibitor κB protein blocking NF-κB signaling confirmed a major role of this pathway in controlling both TNF-α- and IL-1β-induced expression of most of the genes studied. Although dexamethasone exerted limited effects at 1 μM, the thioredoxin inhibitor MOL-294, which regulates the redox state of NF-κB, mainly inhibited adhesion molecule expression. Its most pronounced effect was seen on VCAM-1 mRNA levels, especially in IL-1β-activated endothelium. One micromolar RWJ-67657, an inhibitor of p38 MAPK activity, diminished TNF-α- and IL-1β-induced expression of IL-6, IL-8, and E-selectin but had little effect on VCAM-1 and ICAM-1. Combined treatment of HUVEC with MOL-294 and RWJ-67657 resulted in significant blocking of the expression of E-selectin, IL-6, IL-8, and COX-2. The inhibitory effects were much stronger than those observed with single drug treatment. Application of combinations of drugs that affect multiple targets in activated endothelial cells may therefore be considered as a potential new therapeutic strategy to inhibit inflammatory disease activity.

scholarly journals Nox4 NADPH oxidase mediates oxidative stress and apoptosis caused by TNF-α in cerebral vascular endothelial cells

2009 ◽  
Vol 296 (3) ◽  
pp. C422-C432 ◽  
Author(s):  
Shyamali Basuroy ◽  
Sujoy Bhattacharya ◽  
Charles W. Leffler ◽  
Helena Parfenova
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Nadph Oxidase ◽  
Vascular Endothelium ◽  
Vascular Endothelial Cells ◽  
Primary Source ◽  
Xanthine Oxidase Inhibitors ◽  
Tnf Α ◽  
Diphenylene Iodonium ◽  
Cerebral Vascular

Inflammatory brain disease may damage cerebral vascular endothelium leading to cerebral blood flow dysregulation. The proinflammatory cytokine TNF-α causes oxidative stress and apoptosis in cerebral microvascular endothelial cells (CMVEC) from newborn pigs. We investigated contribution of major cellular sources of reactive oxygen species to endothelial inflammatory response. Nitric oxide synthase and xanthine oxidase inhibitors ( Nω-nitro-l-arginine and allopurinol) had no effect, while mitochondrial electron transport inhibitors (CCCP, 2-thenoyltrifluoroacetone, and rotenone) attenuated TNF-α-induced superoxide (O2•−) and apoptosis. NADPH oxidase inhibitors (diphenylene iodonium and apocynin) greatly reduced TNF-α-evoked O2•− generation and apoptosis. TNF-α rapidly increased NADPH oxidase activity in CMVEC. Nox4, the cell-specific catalytic subunit of NADPH oxidase, is highly expressed in CMVEC, contributes to basal O2•− production, and accounts for a burst of oxidative stress in response to TNF-α. Nox4 small interfering RNA, but not Nox2, knockdown prevented oxidative stress and apoptosis caused by TNF-α in CMVEC. Nox4 is colocalized with HO-2, the constitutive isoform of heme oxygenase (HO), which is critical for endothelial protection against TNF-α toxicity. The products of HO activity, bilirubin and carbon monoxide (CO, as a CO-releasing molecule, CORM-A1), inhibited Nox4-generated O2•− and apoptosis caused by TNF-α stimulation. We conclude that Nox4 is the primary source of inflammation- and TNF-α-induced oxidative stress leading to apoptosis in brain endothelial cells. The ability of CO and bilirubin to combat TNF-α-induced oxidative stress by inhibiting Nox4 activity and/or by O2•− scavenging, taken together with close intracellular compartmentalization of HO-2 and Nox4 in cerebral vascular endothelium, may contribute to HO-2 cytoprotection against inflammatory cerebrovascular disease.

scholarly journals Turnour necrosis factor stimulates endothelin-1 gene expression in cultured bovine endothelial cells

1992 ◽  
Vol 1 (4) ◽  
pp. 263-266 ◽  
Author(s):  
Silvia Orisio ◽  
Marina Morigi ◽  
Carla Zoja ◽  
Norberto Perico ◽  
Giuseppe Remuzzi
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Hypotensive Effect ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Aortic Endothelial Cells ◽  
Endothelin 1 ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

We have studied the effect of human recombinant tumour necrosis factor-α (TNF-α) on gene expression and production of endothelin-1 in cultured bovine aortic endothelial cells. TNF-α (10 and 100 ng ml−1) increased in a time dependent manner the preproendothelin-1 mRNA levels in respect to unstimulated endothelial cells. TNF-α induced endothelin-1 gene expression was associated with a parallel increase in the release of the corresponding peptide in the culture medium. These findings suggest that the enhanced synthesis and release of endothelin-1 occurring in conditions of increased generation of TNF, may act as a modulatory factor that counteracts the hypotensive effect and the excessive platelet aggregation and adhesion induced by TNF.

Inhibitor-κB kinase-β regulates LPS-induced TNF-α production in cardiac myocytes through modulation of NF-κB p65 subunit phosphorylation

2005 ◽  
Vol 289 (5) ◽  
pp. H2103-H2111 ◽  
Author(s):  
Gentzon Hall ◽  
Ishwar S. Singh ◽  
Lisa Hester ◽  
Jeffery D. Hasday ◽  
Terry B. Rogers
Keyword(s):  
Gene Expression ◽  
Cardiac Myocytes ◽  
Ventricular Myocytes ◽  
Myocardial Dysfunction ◽  
Gene Promoter ◽  
Fold Increase ◽  
Dominant Negative ◽  
Mrna Levels ◽  
Tnf Α

TNF-α is recognized as a significant contributor to myocardial dysfunction. Although several studies suggest that members of the NF-κB family of transcription factors are essential regulators of myocardial TNF-α gene expression, recent developments in our understanding of the modulation of NF-κB activity through posttranslational modification of NF-κB subunits suggest that the present view of NF-κB-dependent cytokine expression in heart is incomplete. Therefore, the goal of the present study was to examine the role of p65 subunit phosphorylation in the regulation of TNF-α production in cultured neonatal ventricular myocytes. Bacterial LPS-induced TNF-α production is accompanied by a 12-fold increase in phosphorylation of p65 at Ser536, a modification associated with enhancement of p65 transactivation potential. Pharmacological inhibition of IKK-β reduced LPS-induced TNF-α production 38-fold, TNF-α mRNA levels 6-fold, and IκB-α phosphorylation 5-fold and degraded IκB-α 2-fold and p65 phosphorylation 6-fold. Overexpression of dominant-negative p65 reduced TNF-α production 3.5-fold, whereas overexpression of dominant-negative IKK-β reduced LPS-induced TNF-α production 2-fold and p65 phosphorylation 2-fold. Overexpression of dominant-negative IKK-α had no effect on p65 phosphorylation or TNF-α production, revealing that IKK-β, not IKK-α, plays a central role in regulation of p65 phosphorylation at Ser536 and TNF-α production in heart. Finally, we demonstrated, using a chromatin immunoprecipitation assay, that LPS stimulates recruitment of Ser536-phosphorylated p65 to the TNF-α gene promoter in cardiac myocytes. Taken together, these data provide compelling evidence for the role of NF-κB signaling in TNF-α gene expression in heart and highlight the importance of this proinflammatory gene-regulatory pathway as a potential therapeutic target in the management of cytokine-induced myocardial dysfunction.

scholarly journals Activation of Nuclear Factor κb and bcl-x Survival Gene Expression by Nerve Growth Factor Requires Tyrosine Phosphorylation of IκBα

2001 ◽  
Vol 152 (4) ◽  
pp. 753-764 ◽  
Author(s):  
Nguyen Truc Bui ◽  
Antonia Livolsi ◽  
Jean-Francois Peyron ◽  
Jochen H.M. Prehn
Keyword(s):  
Gene Expression ◽  
Tyrosine Phosphorylation ◽  
Fluorescent Protein ◽  
Nuclear Translocation ◽  
Nuclear Factor Κb ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Nuclear Factor ◽  
Human Neuroblastoma ◽  
Tnf Α

NGF has been shown to support neuron survival by activating the transcription factor nuclear factor-κB (NFκB). We investigated the effect of NGF on the expression of Bcl-xL, an anti–apoptotic Bcl-2 family protein. Treatment of rat pheochromocytoma PC12 cells, human neuroblastoma SH-SY5Y cells, or primary rat hippocampal neurons with NGF (0.1–10 ng/ml) increased the expression of bcl-xL mRNA and protein. Reporter gene analysis revealed a significant increase in NFκB activity after treatment with NGF that was associated with increased nuclear translocation of the active NFκB p65 subunit. NGF-induced NFκB activity and Bcl-xL expression were inhibited in cells overexpressing the NFκB inhibitor, IκBα. Unlike tumor necrosis factor-α (TNF-α), however, NGF-induced NFκB activation occurred without significant degradation of IκBs determined by Western blot analysis and time-lapse imaging of neurons expressing green fluorescent protein–tagged IκBα. Moreover, in contrast to TNF-α, NGF failed to phosphorylate IκBα at serine residue 32, but instead caused significant tyrosine phosphorylation. Overexpression of a Y42F mutant of IκBα potently suppressed NFG-, but not TNF-α–induced NFκB activation. Conversely, overexpression of a dominant negative mutant of TNF receptor-associated factor-6 blocked TNF-α–, but not NGF-induced NFκB activation. We conclude that NGF and TNF-α induce different signaling pathways in neurons to activate NFκB and bcl-x gene expression.

Exercise elevates plasma levels but not gene expression of IL-1β, IL-6, and TNF-α in blood mononuclear cells

2000 ◽  
Vol 89 (4) ◽  
pp. 1499-1504 ◽  
Author(s):  
Andrei I. Moldoveanu ◽  
Roy J. Shephard ◽  
Pang N. Shek
Keyword(s):  
Gene Expression ◽  
Oxygen Uptake ◽  
Mononuclear Cells ◽  
Plasma Concentrations ◽  
Peak Oxygen Uptake ◽  
Cytokine Gene Expression ◽  
Mrna Accumulation ◽  
Peripheral Blood Mononuclear ◽  
Tnf Α ◽  
Blood Mononuclear Cells

Physical activity induces a subclinical inflammatory response, mediated in part by leukocytes, and manifested by elevated concentrations of circulating proinflammatory cytokines, including interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α). However, the source of the cytokines that appear during exercise remains unknown. In this study, we examined exercise-induced changes in plasma cytokine concentrations and their corresponding mRNA expression in peripheral blood mononuclear cells. Ten healthy [peak oxygen uptake = 48.8 ± 6.5 (SD) ml · kg−1 · min−1] but untrained men [age = 25 ± 5 (SD) yr] undertook 3 h of exercise (cycling and inclined walking) at 60–65% peak oxygen uptake. Circulating leukocyte subset counts were elevated during and 2 h postexercise but returned to normal within 24 h. Plasma concentrations of IL-1β, IL-6, and TNF-α peaked at the end of exercise and remained elevated at 2 h (IL-6) and up to 24 h (IL-1β and TNF-α) postexercise. Cytokine gene expression in circulating mononuclear cells was measured by using the reverse transcriptase-polymerase chain reaction; mRNA accumulation did not change with exercise. In conclusion, mRNA accumulation of IL-1β, IL-6, and TNF-α in circulating mononuclear cells is not affected by 3 h of moderate endurance exercise and does not seem to account for the observed increases in plasma cytokines.

scholarly journals Gene Expression of Adhesion Molecules in Endothelial Cells from Patients with Peripheral Arterial Disease Is Reduced after Surgical Revascularization and Pharmacological Treatment

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Franca Marino ◽  
Luigina Guasti ◽  
Matteo Tozzi ◽  
Laura Schembri ◽  
Luana Castiglioni ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Mrna Expression ◽  
Adhesion Molecules ◽  
Mononuclear Cells ◽  
Venous Blood ◽  
Statin Treatment ◽  
Early Event ◽  
Mrna Levels ◽  
Peripheral Blood Mononuclear

Atherosclerosis is an inflammatory disease characterized by immunological activity, in which endothelial dysfunction represents an early event leading to subsequent inflammatory vascular damage. We investigated gene expression of the adhesion molecules (AMs) ICAM-1, VCAM-1, andβ1-integrin in endothelial cells (ECs) isolated from venous blood (circulating EC, cEC) and purified from femoral plaques (pEC) obtained from 9 patients with peripheral artery disease (PAD) submitted to femoral artery thrombendarterectomy (FEA). In addition, in peripheral blood mononuclear cells (PBMCs) of the same subjects, we investigated gene expression of IFN-γ, IL-4, TGF-β, and IL-10. Patients were longitudinally evaluated 1 month before surgery, when statin treatment was established, at the time of surgery, and after 2 and 5 months. All AM mRNA levels, measured by means of real-time PCR, in cEC diminished during the study, up to 41–50% of initial levels at followup. AM mRNA expression was significantly higher in pEC than in cEC. During the study, in PBMCs, TGF-βand IL-10 mRNA levels remained unchanged while IFN-γand IL-4 levels increased; however, the ratio IFN-γ/IL-4 showed no significant modification. In PAD patients, FEA and statin treatment induce a profound reduction of AM expression in cEC and affect cytokine mRNA expression in PBMCs.

Determinants of leptin gene expression in fat depots of lean mice

2002 ◽  
Vol 282 (1) ◽  
pp. R226-R234 ◽  
Author(s):  
Yiying Zhang ◽  
Kai-Ying Guo ◽  
Patricia A. Diaz ◽  
Moonseong Heo ◽  
Rudolph L. Leibel
Keyword(s):  
Gene Expression ◽  
Glucocorticoid Receptor ◽  
Insulin Receptor ◽  
Physiological Role ◽  
Mrna Levels ◽  
Strongly Correlated ◽  
Fat Depots ◽  
Tnf Α ◽  
Adipocyte Volume

The relationship of leptin gene expression to adipocyte volume was investigated in lean 10-wk-old male C57BL/6J mice. mRNA levels for leptin, insulin receptor, glucocorticoid receptor, and tumor necrosis factor (TNF)-α in inguinal, epididymal, and retroperitoneal adipose tissues were quantified and related to adipocyte volume. Leptin mRNA levels were highly correlated with adipocyte volume within each fat depot. Multiple regression analysis of pooled data from the three depots showed that leptin mRNA levels were strongly correlated with adipocyte volumes (β = 0.84, P < 0.001) and, to a smaller degree, with glucocorticoid receptor mRNA levels (β = 0.36, P < 0.001). Depot of origin had no effect ( P > 0.9). Rates of leptin secretion in vitro were strongly correlated with leptin mRNA levels ( r = 0.89, P < 0.001). mRNA levels for TNF-α, insulin receptor, and glucocorticoid receptor showed no significant correlation with adipocyte volume. These results demonstrate that depot-specific differences in leptin gene expression are mainly related to the volumes of the constituent adipocytes. The strong correlation between leptin gene expression and adipocyte volume supports leptin's physiological role as a humoral signal of fat mass.

Gene expression after resumption of development of Artemia franciscana cryptobiotic embryos

1994 ◽  
Vol 72 (3-4) ◽  
pp. 78-83 ◽  
Author(s):  
Ricardo Escalante ◽  
Alberto García-Sáez ◽  
Maria-Asunción Ortega ◽  
Leandro Sastre
Keyword(s):  
Gene Expression ◽  
Time Course ◽  
Developmental Stages ◽  
Artemia Franciscana ◽  
Mrna Levels ◽  
Muscle Actin ◽  
Mrna Accumulation ◽  
Α Subunit ◽  
Steady State Levels ◽  
Cyst Development

The steady-state levels of six different mRNAs have been studied during Artemia franciscana development. Some of these mRNAs are present in the cryptobiotic cyst, like those coding for cytoplasmic actins, sarcoplasmic/endoplasmic reticulum Ca2+-ATPase, and the Na+,K+-ATPase α-subunit isoform coded by the clone pArATNa136. The expression of these mRNAs is markedly induced during cyst development. A small increase in mRNA levels can be observed for some genes at very early stages of development (2 h). The main increase is observed between 4 and 16 h of development for all these genes, although the time course of mRNA accumulation is different for each one of the genes studied. Some other genes, like those coding for muscle actin (actin 3) or the Na+,K+-ATPase α-subunit isoform coded by the cDNA clone α2850, are not expressed in the cyst before resumption of development and their expression is induced after 10 or 6 h of development, respectively. These data on the kinetic of mRNA accumulation provide the information required to determine transcriptionally active developmental stages, necessary to study in more detail the mechanisms of transcriptional regulation during activation of cryptobiotic cysts and resumption of embryonic development.Key words: Artemia, gene expression, actin, Na,K-ATPase, Ca2+-ATPase.

scholarly journals Phorbol Ester-Induced Human Cytomegalovirus Major Immediate-Early (MIE) Enhancer Activation through PKC-Delta, CREB, and NF-κB Desilences MIE Gene Expression in Quiescently Infected Human Pluripotent NTera2 Cells

2010 ◽  
Vol 84 (17) ◽  
pp. 8495-8508 ◽  
Author(s):  
Xiaoqiu Liu ◽  
Jinxiang Yuan ◽  
Allen W. Wu ◽  
Patrick W. McGonagill ◽  
Courtney S. Galle ◽  
...  
Keyword(s):  
Gene Expression ◽  
Human Cytomegalovirus ◽  
Binding Sites ◽  
Molecular Mechanisms ◽  
Cell Model ◽  
Gene Activation ◽  
Dominant Negative ◽  
Immediate Early ◽  
Signaling Cascade ◽  
Pkc Delta

ABSTRACT The ways in which human cytomegalovirus (HCMV) major immediate-early (MIE) gene expression breaks silence from latency to initiate the viral replicative cycle are poorly understood. A delineation of the signaling cascades that desilence the HCMV MIE genes during viral quiescence in the human pluripotent N-Tera2 (NT2) cell model provides insight into the molecular mechanisms underlying HCMV reactivation. In this model, we show that phorbol 12-myristate 13-acetate (PMA) immediately activates the expression of HCMV MIE RNA and protein and greatly increases the MIE-positive (MIE+) NT2 cell population density; levels of Oct4 (pluripotent cell marker) and HCMV genome penetration are unchanged. Decreasing PKC-delta activity (pharmacological, dominant-negative, or RNA interference [RNAi] method) attenuates PMA-activated MIE gene expression. MIE gene activation coincides with PKC-delta Thr505 phosphorylation. Mutations in MIE enhancer binding sites for either CREB (cyclic AMP [cAMP] response element [CRE]) or NF-κB (κB) partially block PMA-activated MIE gene expression; the ETS binding site is negligibly involved, and κB does not confer MIE gene activation by vasoactive intestinal peptide (VIP). The PMA response is also partially attenuated by the RNAi-mediated depletion of the CREB or NF-κB subunit RelA or p50; it is not diminished by TORC2 knockdown or accompanied by TORC2 dephosphorylation. Mutations in both CRE and κB fully abolish PMA-activated MIE gene expression. Thus, PMA stimulates a PKC-delta-dependent, TORC2-independent signaling cascade that acts through cellular CREB and NF-κB, as well as their cognate binding sites in the MIE enhancer, to immediately desilence HCMV MIE genes. This signaling cascade is distinctly different from that elicited by VIP.

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