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Riaz IB, Faridi W, Husnain M, Malik SU, Sipra QUAR, Gondal FR, Xie H, Yadav S, Kohli M. Adjuvant Therapy in High-Risk Renal Cell Cancer: A Systematic Review and Meta-analysis. Mayo Clin Proc 2019; 94:1524-1534. [PMID: 31303430 DOI: 10.1016/j.mayocp.2019.01.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 12/27/2018] [Accepted: 01/08/2019] [Indexed: 01/30/2023]
Abstract
OBJECTIVE To perform a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating risk-benefit for adjuvant postoperative treatments in high-risk renal cell carcinoma by assessing reported disease-free survival (DFS), overall survival (OS), toxicity, and quality of life. METHODS A literature search was performed in PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials to identify relevant RCTs (from database inception through May 15, 2018). The results of the ATLAS trial were published while writing this manuscript, and the manuscript was updated accordingly. A generic variance-weighted random effects model was used to derive estimates for efficacy and common adverse effects. Heterogeneity was assessed using the Cochran Q statistic and was quantified using the I2 test. RESULTS Adjuvant therapy with tyrosine kinase inhibitors compared with placebo was observed to have a DFS hazard ratio [HR] of 0.92 (95% CI, 0.83-1.01) and an OS HR of 1.01 (95% CI, 0.89-1.15) (4 RCTs; 4417 patients). Analysis of DFS for sunitinib compared with placebo (n=1909) in the adjuvant setting detected an HR of 0.90 (95% CI, 0.67-1.19). Increased risk of grade 3 or 4 adverse events (relative risk [RR]=2.6; 95% CI, 2.28-2.97), diarrhea (RR=9.89; 95% CI, 4.22-23.14), fatigue (RR=3.11; 95% CI, 1.86-5.18), hypertension (RR=3.63; 95% CI, 2.99-4.41), and palmar/plantar dysesthesia (RR=2.70; 95% CI, 2.47-2.96) was observed. CONCLUSION Adjuvant vascular endothelial growth factor tyrosine kinase inhibitors in high-risk renal cell carcinoma did not improve OS or DFS, and there was a significant increased risk of toxicity in greater than half of the patients, leading to a decline in quality of life.
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Affiliation(s)
- Irbaz B Riaz
- Department of Oncology, Mayo Clinic, Rochester, MN.
| | - Warda Faridi
- Division of Hematology-Oncology, University of Arizona, Tucson
| | - Muhammad Husnain
- Department of Medicine, University of Arizona, Tucson; Division of Hematology and Oncology, University of Miami, FL
| | | | | | | | - Hao Xie
- Department of Oncology, Mayo Clinic, Rochester, MN
| | | | - Manish Kohli
- Department of Oncology, Mayo Clinic, Rochester, MN.
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Paudel P, Wagle A, Seong SH, Park HJ, Jung HA, Choi JS. A New Tyrosinase Inhibitor from the Red Alga Symphyocladia latiuscula (Harvey) Yamada (Rhodomelaceae). Mar Drugs 2019; 17:md17050295. [PMID: 31108882 PMCID: PMC6562427 DOI: 10.3390/md17050295] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 05/13/2019] [Accepted: 05/15/2019] [Indexed: 12/21/2022] Open
Abstract
A marine red alga, Symphyocladia latiuscula (Harvey) Yamada (Rhodomelaceae), is a rich source of bromophenols with a wide array of biological activities. This study investigates the anti-tyrosinase activity of the alga. Moderate activity was demonstrated by the methanol extract of S. latiuscula, and subsequent column chromatography identified three bromophenols: 2,3,6-tribromo-4,5-dihydroxybenzyl methyl alcohol (1), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (2), and bis-(2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether) (3). Bromophenols 1 and 3 exhibited potent competitive tyrosinase inhibitory activity against l-tyrosine substrates, with IC50 values of 10.78 ± 0.19 and 2.92 ± 0.04 μM, respectively. Against substrate l-3,4-dihydroxyphenylalanine (l-DOPA), compounds 1 and 3 demonstrated moderate activity, while 2 showed no observable effect. The experimental data were verified by a molecular docking study that found catalytic hydrogen and halogen interactions were responsible for the activity. In addition, compounds 1 and 3 exhibited dose-dependent inhibitory effects in melanin and intracellular tyrosinase levels in α-melanocyte-stimulating hormone (α-MSH)-induced B16F10 melanoma cells. Compounds 3 and 1 were the most effective tyrosinase inhibitors. In addition, increasing the bromine group number increased the mushroom tyrosinase inhibitory activity.
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Affiliation(s)
- Pradeep Paudel
- Department of Food and Life Science, Pukyong National University, Busan 48513, Korea.
| | - Aditi Wagle
- Department of Food and Life Science, Pukyong National University, Busan 48513, Korea.
| | - Su Hui Seong
- Department of Food and Life Science, Pukyong National University, Busan 48513, Korea.
| | - Hye Jin Park
- Department of Food Science and Nutrition, Changshin University, Gyeongsangnam-do 51352, Korea.
| | - Hyun Ah Jung
- Department of Food Science and Human Nutrition, Chonbuk National University, Jeonju 54896, Korea.
| | - Jae Sue Choi
- Department of Food and Life Science, Pukyong National University, Busan 48513, Korea.
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Abstract
Peroxynitrite is a reactive nitrogen species produced in the intravascular compartment from superoxide anion and nitric oxide. Peroxynitrite destroys blood plasma proteins and membranes of red blood cells and of platelets. This explains why excessive production of peroxynitrite contributes to diseases and to ageing. Therapeutics that antagonize peroxynitrite may delay ageing and the progression of disease. We developed an in vitro assay that allows the investigation of the oxidative damage caused by peroxynitrite in the intravascular compartment. This assay correlates the damage with the rate of formation of protein carbonyl groups, 3-nitrotyrosine (3-NT) and thiobarbituric acid reactive substances. Using this assay, we evaluated the ability of phenelzine, a scavenger of reactive aldehydes, to antagonize the effects of peroxynitrite. Herein, we showed that phenelzine significantly decreased the lipid peroxidative damage caused by peroxynitirite in blood plasma and platelets. Moreover, it inhibited carbonyl group and 3-NT formation in blood plasma and platelet proteins.
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Affiliation(s)
- Ayman G Mustafa
- a School of Medicine , Jordan University of Science and Technology , Irbid , Jordan
| | - Othman Al-Shboul
- a School of Medicine , Jordan University of Science and Technology , Irbid , Jordan
| | - Mahmoud A Alfaqih
- b Department of Physiology and Biochemistry, Faculty of Medicine , Jordan University of Science and Technology , Irbid , Jordan
| | - Mohammad A Al-Qudah
- a School of Medicine , Jordan University of Science and Technology , Irbid , Jordan
| | - Ahmed N Al-Dwairi
- a School of Medicine , Jordan University of Science and Technology , Irbid , Jordan
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Sabadashka M, Sybirna N. Reduction of radiationinduced nitrative stress in leucocytes and kidney cells of rats upon administration of polyphenolic complex concentrates from red wine. Tsitol Genet 2016; 50:46-56. [PMID: 30480409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The research has shown that exposure to ionizing radiation at the dose of 30 cGy leads to the activation of NO-synthase way of nitrogen oxide synthesis, as well as to the accumulation of its stable metabolites and 3’-nitrotyrosine modified proteins in rat peripheral blood leucocytes and the renal cortical layer. NO-synthase activity was preserved at the control value through the consumption of red wine natural polyphenolic complex concentrates by the irradiated animals. The content of proteins modified by tyrosine nitration decreased in the early period of post-radiation exposure due to the influence of the investigated concentrate. Thus the ability of red wine natural polyphenolic complex concentrates to prevent adverse changes in L-arginine/NO system and, therefore, inhibit the development of nitrative stress induced by low doses of ionizing radiation has been proved experimentally.
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Ascenzi P, Leboffe L, di Masi A, Trezza V, Fanali G, Gioia M, Coletta M, Fasano M. Ligand binding to the FA3-FA4 cleft inhibits the esterase-like activity of human serum albumin. PLoS One 2015; 10:e0120603. [PMID: 25790235 PMCID: PMC4366387 DOI: 10.1371/journal.pone.0120603] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 01/24/2015] [Indexed: 12/19/2022] Open
Abstract
The hydrolysis of 4-nitrophenyl esters of hexanoate (NphOHe) and decanoate (NphODe) by human serum albumin (HSA) at Tyr411, located at the FA3-FA4 site, has been investigated between pH 5.8 and 9.5, at 22.0°C. Values of Ks, k+2, and k+2/Ks obtained at [HSA] ≥ 5×[NphOXx] and [NphOXx] ≥ 5×[HSA] (Xx is NphOHe or NphODe) match very well each other; moreover, the deacylation step turns out to be the rate limiting step in catalysis (i.e., k+3 << k+2). The pH dependence of the kinetic parameters for the hydrolysis of NphOHe and NphODe can be described by the acidic pKa-shift of a single amino acid residue, which varies from 8.9 in the free HSA to 7.6 and 7.0 in the HSA:NphOHe and HSA:NphODe complex, respectively; the pK>a-shift appears to be correlated to the length of the fatty acid tail of the substrate. The inhibition of the HSA-Tyr411-catalyzed hydrolysis of NphOHe, NphODe, and 4-nitrophenyl myristate (NphOMy) by five inhibitors (i.e., diazepam, diflunisal, ibuprofen, 3-indoxyl-sulfate, and propofol) has been investigated at pH 7.5 and 22.0°C, resulting competitive. The affinity of diazepam, diflunisal, ibuprofen, 3-indoxyl-sulfate, and propofol for HSA reflects the selectivity of the FA3-FA4 cleft. Under conditions where Tyr411 is not acylated, the molar fraction of diazepam, diflunisal, ibuprofen, and 3-indoxyl-sulfate bound to HSA is higher than 0.9 whereas the molar fraction of propofol bound to HSA is ca. 0.5.
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Affiliation(s)
- Paolo Ascenzi
- Interdepartmental Laboratory of Electron Microscopy, Roma Tre University, Via della Vasca Navale 79, I-00146 Roma, Italy
| | - Loris Leboffe
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, I-00146 Roma, Italy
| | - Alessandra di Masi
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, I-00146 Roma, Italy
| | - Viviana Trezza
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, I-00146 Roma, Italy
| | - Gabriella Fanali
- Biomedical Research Division, Department of Theoretical and Applied Sciences, University of Insubria, Via Alberto da Giussano 12, I-21052 Busto Arsizio (VA), Italy
| | - Magda Gioia
- Department of Clinical Sciences and Translational Medicine, University of Roma “Tor Vergata”, Via Montpellier 1, I-00133 Roma, Italy
- Interuniversity Consortium for the Research on the Chemistry of Metals in Biological Systems, Via Celso Ulpiani 27, I-70126 Bari, Italy
| | - Massimo Coletta
- Department of Clinical Sciences and Translational Medicine, University of Roma “Tor Vergata”, Via Montpellier 1, I-00133 Roma, Italy
- Interuniversity Consortium for the Research on the Chemistry of Metals in Biological Systems, Via Celso Ulpiani 27, I-70126 Bari, Italy
| | - Mauro Fasano
- Biomedical Research Division, Department of Theoretical and Applied Sciences, University of Insubria, Via Alberto da Giussano 12, I-21052 Busto Arsizio (VA), Italy
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Liu Q, Rehman H, Krishnasamy Y, Ramshesh VK, Theruvath TP, Chavin KD, Schnellmann RG, Lemasters JJ, Zhong Z. Role of inducible nitric oxide synthase in mitochondrial depolarization and graft injury after transplantation of fatty livers. Free Radic Biol Med 2012; 53:250-9. [PMID: 22609250 PMCID: PMC3392495 DOI: 10.1016/j.freeradbiomed.2012.05.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 04/12/2012] [Accepted: 05/07/2012] [Indexed: 12/23/2022]
Abstract
This study investigated the role of inducible nitric oxide synthase (iNOS) in failure of ethanol-induced fatty liver grafts. Rat livers were explanted 20 h after gavaging with ethanol (5 g/kg) and storing in UW solution for 24h before implantation. Hepatic oil red O staining-positive areas increased from ∼2 to ∼33% after ethanol treatment, indicating steatosis. iNOS expression increased ∼8-fold after transplantation of lean grafts (LG) and 25-fold in fatty grafts (FG). Alanine aminotransferase release, total bilirubin, hepatic necrosis, TUNEL-positive cells, and cleaved caspase-3 were higher in FG than LG. A specific iNOS inhibitor 1400W (5 μM in the cold-storage solution) blunted these alterations by >42% and increased survival of fatty grafts from 25 to 88%. Serum nitrite/nitrate and hepatic nitrotyrosine adducts increased to a greater extent after transplantation of FG than LG, indicating reactive nitrogen species (RNS) overproduction. Phospho-c-Jun and phospho-c-Jun N-terminal kinase-1/2 (JNK1/2) were higher in FG than in LG, indicating more JNK activation in fatty grafts. RNS formation and JNK activation were blunted by 1400W. Mitochondrial polarization and cell death were visualized by intravital multiphoton microscopy of rhodamine 123 and propidium iodide, respectively. After implantation, viable cells with depolarized mitochondria were 3-fold higher in FG than in LG and 1400W decreased mitochondrial depolarization in FG to the levels of LG. Taken together, iNOS is upregulated after transplantation of FG, leading to excessive RNS formation, JNK activation, mitochondrial dysfunction, and severe graft injury. The iNOS inhibitor 1400W could be an effective therapy for primary nonfunction of fatty liver grafts.
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Affiliation(s)
- Qinlong Liu
- Department of Pharmaceutical & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
- Department of General Surgery, the Second Affiliated Hospital of Dalian Medical University, Dalian, China
| | - Hasibur Rehman
- Department of Pharmaceutical & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Yasodha Krishnasamy
- Department of Pharmaceutical & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Venkat K. Ramshesh
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Tom P. Theruvath
- Department of Pharmaceutical & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Kenneth D. Chavin
- Department of Surgery, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Rick G. Schnellmann
- Department of Pharmaceutical & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
- Ralph H. Johnson VA Medical Center, Charleston, SC 29403, USA
| | - John J. Lemasters
- Department of Pharmaceutical & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
- Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Zhi Zhong
- Department of Pharmaceutical & Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425, USA
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA
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Tsuboi M, Etoh H, Kato K, Nakatugawa H, Kato H, Maejima Y, Matsumoto G, Mori H, Hosokawa M, Miyashita K, Tokuda H, Suzuki N, Maoka T. Nitrocapsanthin and nitrofucoxanthin, respective products of capsanthin and fucoxanthin reaction with peroxynitrite. J Agric Food Chem 2011; 59:10572-10578. [PMID: 21899264 DOI: 10.1021/jf203493k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The in vitro reactivity of capsanthin (1) and fucoxanthin (2) with peroxynitrite was investigated, and the reaction products produced by scavenging with peroxynitrite were analyzed. (14'Z)-Nitrocapsanthin (3) and 12-nitrocapsanthin (4) were isolated from the products of the reaction of capsanthin with peroxynitrite. Similarly, (14Z)-15-nitrofucoxanthin (5), (11Z)-11-nitrofucoxanthin (6), and (14Z,9'Z)-15-nitrofucoxanthin (7) were obtained from the reaction of peroxynitrite reaction with fucoxanthin. Capsanthin and fucoxanthin inhibited the nitration of tyrosine by peroxynitrite. Furthermore, nitrocapsanthins (3 and 4) and nitrofucoxanthins (5 and 6) exhibited an inhibitory effect on Epstein-Barr virus early antigen activation in Raji cells and an antiproliferative effect on human pancreatic carcinoma. Moreover, nitrocapsanthins (3 and 4) inhibited carcinogensis of mouse skin tumors initiated by 7,12-dimethylbenz[a]anthracene (DMBN).
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Affiliation(s)
- Makoto Tsuboi
- Graduate of Science and Technology, Shizuoka University , 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
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García-Molina F, Muñoz-Muñoz JL, Martínez-Ortiz F, García-Ruíz PA, Tudela J, García-Cánovas F, Rodríguez-López JN. Tetrahydrofolic Acid is a potent suicide substrate of mushroom tyrosinase. J Agric Food Chem 2011; 59:1383-1391. [PMID: 21265541 DOI: 10.1021/jf1035433] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The coenzyme tetrahydrofolic acid is the most rapid suicide substrate of tyrosinase that has been characterized to date. A kinetic study of the suicide inactivation process provides the kinetic constants that characterize it: λ(max), the maximum apparent inactivation constant; r, the partition ratio or the number of turnovers made by one enzyme molecule before inactivation; and k(cat) and K(m), the catalytic and Michaelis constants, respectively. From these values, it is possible to establish the ratio λ(max)/K(m), which represents the potency of the inactivation process. Besides acting as a suicide substrate of tyrosinase, tetrahydrofolic acid reduces o-quinones generated by the enzyme in its action on substrates, such as l-tyrosine and l-DOPA (o-dopaquinone), thus inhibiting enzymatic browning.
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Affiliation(s)
- Francisco García-Molina
- Grupo de Investigación de Enzimología (GENZ), Departamento de Bioquímica y Biología Molecular-A, Facultad de Biología, Universidad de Murcia , Espinardo, Murcia E-30100, Spain
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Park SH, Kim DS, Park SH, Shin JW, Youn SW, Park KC. Inhibitory effect of p-coumaric acid by Rhodiola sachalinensis on melanin synthesis in B16F10 cells. Pharmazie 2008; 63:290-295. [PMID: 18468389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Rhodiola has been widely used in traditional Asian medicine. In this study, we tested the hypopigmentation effects of R. sachalinensis and its active compounds including catechin, chlorogenic acid, p-coumaric acid, and p-tyrosol. Results have shown that only p-coumaric acid inhibits melanin synthesis in B16F10 cells. However, p-coumaric acid did not inhibit tyrosinase activity when L-DOPA was used as a substrate. Instead, p-coumaric acid inhibited tyrosinase activity when L-tyrosine was used as a substrate. We further analyzed the changes of cAMP responsive element binding protein (CREB) phosphorylation and tyrosinase gene expression. The results indicate that p-coumaric acid does not affect CREB phosphorylation or tyrosinase protein production. In turn, these findings demonstrate that p-coumaric acid has no effect on the upstream regulation of tyrosinase gene expression, although p-coumaric acid showed a significant inhibitory effect on melanogenesis. Because p-coumaric acid showed different effects on tyrosinase activity according to different substrates, we tested whether tyrosinase can utilize p-coumaric acid as a substrate. Our findings revealed that competitive inhibition occurs between p-coumaric acid and tyrosine. Consequently, this finding could be a primary mechanism for the hypopigmenting action of p-coumaric acid.
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Affiliation(s)
- So-Hee Park
- Department of Dermatology, Seoul National University College of Medicine, Seoul, Republic of Korea
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Diaz-Ricart M, Palomo M, Fuste B, Lopez-Vilchez I, Carbo C, Perez-Pujol S, White JG, Escolar G. Inhibition of tyrosine kinase activity prevents the adhesive and cohesive properties of platelets and the expression of procoagulant activity in response to collagen. Thromb Res 2008; 121:873-83. [PMID: 17904203 DOI: 10.1016/j.thromres.2007.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2007] [Revised: 08/02/2007] [Accepted: 08/03/2007] [Indexed: 11/22/2022]
Abstract
INTRODUCTION Platelet activation leads to signal transduction mechanisms, in which phosphotyrosine proteins play a relevant role. MATERIAL AND METHODS Platelet suspensions were independently activated by collagen and thrombin in the absence and in the presence of two tyrosine kinase inhibitors, tyrphostin 47 and genistein. Samples were processed to visualize morphological changes by electron microscopy, to evaluate changes in cytoskeletal assembly, to analyze modifications in the expression of activation dependent antigens, and the procoagulant activity at the surface level by flow cytometry. Additional experiments applying flow conditions were performed to assess the effect of inhibiting tyrosine phosphorylation on primary platelet adhesion and fibrin formation. RESULTS Inhibition of tyrosine phosphorylation blocked shape change and cytoskeletal assembly induced by collagen, and inhibited, though partially, those effects due to thrombin. Both activating agents induced the expression of the intraplatelet antigens CD62P and CD63 at the surface, although only collagen promoted expression of anionic phospholipids. Both tyrphostin 47 and genistein prevented those effects. The extent of platelet adhesion on both collagen-coated and subendothelial surfaces was significantly diminished by the presence of the tyrosine kinase inhibitors assayed. Fibrin formation was also significantly reduced. CONCLUSIONS Platelet shape change and secretion during platelet activation depends on tyrosine phosphorylation. In addition, primary adhesion of platelets induces signaling through tyrosine kinases to achieve full spreading, and results in the exposure of a procoagulant surface on platelets.
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Affiliation(s)
- Maribel Diaz-Ricart
- Servicio de Hemoterapia-Hemostasia, Hospital Clínic, IDIBAPS, Universidad de Barcelona, Spain.
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Singh IN, Sullivan PG, Hall ED. Peroxynitrite-mediated oxidative damage to brain mitochondria: Protective effects of peroxynitrite scavengers. J Neurosci Res 2007; 85:2216-23. [PMID: 17510982 DOI: 10.1002/jnr.21360] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Peroxynitrite-mediated oxidative damage has been implicated in brain mitochondrial respiratory dysfunction after traumatic brain injury (TBI), which precedes the onset of neuronal loss. The aim of this study was to investigate the detrimental effects of the peroxynitrite donor SIN-1 (3-morpholinosydnonimine) on isolated brain mitochondria and to screen penicillamine, a stoichiometric (1:1) peroxynitrite-scavenging agent, and tempol, a catalytic scavenger of peroxynitrite-derived radicals, as antioxidant mitochondrial protectants. Exposure of the isolated mitochondria to SIN-1 caused a significant dose-dependent decrease in the respiratory control ratio and was accompanied by a significant increase in state II respiration, followed by significant decreases (P < 0.05) in states III and V. These functional alterations occurred together with significant increases in mitochondrial protein carbonyl (PC), lipid peroxidation-related 4-hydroxynonenal (4-HNE), and 3-nitrotyrosine (3-NT) content. Penicillamine hydrochloride (10 microM) partially but significantly (P < 0.05) protected against SIN-1-induced decreases in states III and V. However, a 2.5 microM concentration of tempol was able to significantly antagonize a 4-fold molar excess (10 microM) concentration of SIN-1 as effectively as were higher tempol concentrations, consistent with the likelihood that tempol works by a catalytic mechanism. The protection of mitochondrial respiration by penicillamine and tempol occurred in parallel with attenuation of PC, 4-HNE, and 3-NT. These results indicate that SIN-1 causes mitochondrial oxidative damage and complex I dysfunction and that antioxidant compounds that target either peroxynitrite or its radicals may be effective mitochondrial protectants in the treatment of neural injury.
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Affiliation(s)
- Indrapal N Singh
- Spinal Cord & Brain Injury Research Center, University of Kentucky College of Medicine, Lexington, KY 40536-0509, USA
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Cruz C, Correa-Rotter R, Sánchez-González DJ, Hernández-Pando R, Maldonado PD, Martínez-Martínez CM, Medina-Campos ON, Tapia E, Aguilar D, Chirino YI, Pedraza-Chaverri J. Renoprotective and antihypertensive effects of S-allylcysteine in 5/6 nephrectomized rats. Am J Physiol Renal Physiol 2007; 293:F1691-8. [PMID: 17686953 DOI: 10.1152/ajprenal.00235.2007] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Progressive renal damage and hypertension are associated with oxidative and nitrosative stress. On the other hand, S-allylcysteine (SAC), the most abundant organosulfur compound in aged garlic extract (AG), has antioxidant properties. The effects of SAC and AG on blood pressure, renal damage, and oxidative and nitrosative stress were studied in five-sixths nephrectomized rats treated with SAC (200 mg/kg ip) and AG (1.2 ml/kg ip) every other day for 30 days. Proteinuria and serum creatinine and blood urea nitrogen concentrations were measured on days 0, 5, 10, 15, and 30, and systolic blood pressure was recorded on days 0, 15, and 30. The degree of glomerulosclerosis and tubulointerstitial damage, the immunostaining for inducible nitric oxide synthase, 3-nitrotyrosine, poly(ADP-ribose), and the subunits of NADPH oxidase p22phox and gp91phox, and the activity of SOD were determined on day 30. SAC and AG reduced hypertension, renal damage, and the abundance of inducible nitric oxide synthase, 3-nitrotyrosine, poly(ADP-ribose), p22phox, and gp91phox and increased SOD activity. Our data suggest that the antihypertensive and renoprotective effects of SAC and AG are associated with their antioxidant properties and that they may be used to ameliorate hypertension and delay the progression of renal damage.
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Affiliation(s)
- Cristino Cruz
- Departamento de Nefrología y Metabolismo Mineral, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico
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Abstract
Mastocytosis is characterized by pathologic mast cell accumulation and activation in tissues. Establishment of objective histopathologic and molecular criteria for diagnosis of mastocytosis has allowed sensitive detection of mast cells with aberrant features in patients presenting with suspected mast cell activation symptoms. Frequent detection of the D816V c-kit tyrosine kinase mutation in mastocytosis has led to evaluation of small-molecular-weight tyrosine kinase inhibitors as mast cell cytoreductive agents. In vitro experiments, however, showed that mast cells carrying the D816V c-kit mutation were resistant to the prototypical tyrosine kinase inhibitor imatinib. Efficacy of newer generation tyrosine inhibitors in mast cell disease is currently being evaluated.
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Affiliation(s)
- Susan I Hungness
- Department of Internal Medicine, Division of Allergy and Clinical Immunology, University of Michigan, 5520-B, MSRB-1, Box 0600, 1150 W. Medical Center Drive, Ann Arbor, MI 48109-0600, USA
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14
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Fukuyama N, Jujo S, Ito I, Shizuma T, Myojin K, Ishiwata K, Nagano M, Nakazawa H, Mori H. Kurozu moromimatsu inhibits tumor growth of Lovo cells in a mouse model in vivo. Nutrition 2007; 23:81-6. [PMID: 17189090 DOI: 10.1016/j.nut.2006.10.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Revised: 09/25/2006] [Accepted: 10/12/2006] [Indexed: 01/18/2023]
Abstract
OBJECTIVE In Japan, rice vinegar that has been matured and fermented for years in earthenware jars is considered a health food with anticolon cancer action. It is divided into the liquid component (Kurozu) and the sediment (Kurozu moromimatsu), which contains large amounts of organic materials and minerals. The effect of Kurozu moromimatsu (Kurozu-M) on cancer has not yet been examined. In this study, we examined the activity of Kurozu-M on colon cancer and investigated the mechanisms involved, focusing on active oxygen generation, apoptosis, and metalloproteinases (MMPs). METHODS We used Lovo cells transplanted into nude mice as an experimental model. We measured the tumor volume and MMP levels and conducted hematoxylin-eosin staining (for polymorphonuclear leukocytes), terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling staining (for apoptosis), and immunostaining for nitrotyrosine (a marker of active oxygen generation) in control, Kurozu-treated, and Kurozu-M--treated groups. RESULTS The tumor volume was the same in the control group (231 +/- 36 mm(3)) and Kurozu group (238 +/- 52 mm(3)), but was significantly reduced in the Kurozu-M group (152 +/- 28 mm(3), P < 0.001 versus control). Apoptosis of tumor cells and accumulation of polymorphonuclear leukocytes were not observed. Nitrotyrosine production, total MMP levels, and MMP activation were significantly reduced in the Kurozu-M group. CONCLUSION The administration of Kurozu-M prolonged the lifespan of cancer cell-transplanted mice, inhibited tumor progression, and reduced nitrotyrosine production and MMP activation, but did not induce apoptosis.
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Affiliation(s)
- Naoto Fukuyama
- Department of Physiology, Tokai University, School of Medicine, Isehara, Kanagawa, Japan.
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15
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Olmos A, Máñez S, Giner RM, Recio MC, Ríos JL. Protein tyrosine nitration induced by heme/hydrogen peroxide: inhibitory effect of hydroxycinnamoyl conjugates. Planta Med 2007; 73:20-6. [PMID: 17109254 DOI: 10.1055/s-2006-951744] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The present study was designed to optimize the experimental conditions that govern the heme-catalyzed nitration of protein tyrosine residues by nitrite, and, within this framework, to study the effects of 3,5-dicaffeoylquinic acid and its methyl ester, both of which have been previously reported to be antioxidants and inhibitors of leukocyte functions. Although the presence of hydrogen peroxide is essential in cell-free systems, an excess of this compound was found to be detrimental, so much so that an increase in hemin concentration actually resulted in an inverse effect on the reaction, depending on the levels of fixed hydrogen peroxide. Unlike previous reports on nitrite-induced albumin tyrosine nitration, the optimal pH here was found to be 7.0. The two caffeoyl conjugates tested were found to be effective inhibitors of protein nitration, with IC50 values ranging from 20 - 30 microM, regardless of the presence of bicarbonate. For the inhibition of myeloperoxidase-catalyzed protein nitration by human polymorphonuclear leukocytes stimulated by phorbol ester, the potencies obtained were up to two times higher. This is the first time that caffeoylquinic esters have been reported as inhibitors of heme-based protein nitration.
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Affiliation(s)
- Ana Olmos
- Departament de Farmacologia, Universitat de València, Valencia, Spain
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16
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Di Paola R, Mazzon E, Maiere D, Zito D, Britti D, De Majo M, Genovese T, Cuzzocrea S. Rosiglitazone reduces the evolution of experimental periodontitis in the rat. J Dent Res 2006; 85:156-61. [PMID: 16434734 DOI: 10.1177/154405910608500208] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The peroxisome proliferator-activated receptor-gamma (PPAR-gamma) receptor appears to play a pivotal role in the regulation of cellular proliferation and inflammation. Recent evidence also suggests that rosiglitazone, a PPAR-gamma agonist, reduces acute and chronic inflammation. We hypothesized that rosiglitazone would attenuate periodontal inflammation. In the present study, we investigated the effects of rosiglitazone in a rat model of ligature-induced periodontitis. At day 8, ligation significantly induced an increase in neutrophil infiltration, as well as of gingivomucosal tissue expression of iNOS, nitrotyrosine formation, and poly (ADP-ribose) polymerase activation. Ligation significantly increased Evans blue extravasation in gingivomucosal tissue and alveolar bone destruction. Intraperitoneal injection of rosiglitazone (10 mg/kg 10% DMSO daily for 8 days) significantly decreased all of the parameters of inflammation, as described above. Analysis of these data demonstrated that rosiglitazone exerted an anti-inflammatory role during experimental periodontitis, and was able to ameliorate the tissue damage associated with ligature-induced periodontitis.
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Affiliation(s)
- R Di Paola
- Department of Clinical and Experimental Medicine and Pharmacology, Torre Biologica, Policlinico Universitario, Via C. Valeria, Gazzi, 98100 Messina, Italy
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17
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Abstract
Inflammation contributes greatly to the pathogenesis of bronchopulmonary dysplasia. In previous studies, we showed that blocking neutrophil influx by treatment with SB265610, a selective CXCR2 antagonist, could partly reduce superoxide accumulation and preserve alveolar development in 60% O(2)-exposed newborn rats. The purpose of this study was to further investigate the role of neutrophils in the formation of reactive oxygen and nitrogen species mediating hyperoxia-impaired lung development. We found that hydroxyl radical formation and lipid peroxidation in rat lungs were significantly increased during 60% O(2) exposure. These increases were attenuated by the administration of SB265610. In addition, SB265610 largely inhibited protein nitration induced by hyperoxia. SB265610 partly prevented the hyperoxia-enhanced bronchoalveolar lavage (BAL) protein content in 60% O(2)-exposed animals. Our results demonstrate that neutrophils have a pivotal role in hydroxyl radical formation, lipid peroxidation and protein nitration. Taken together with our previous studies, the present findings show that blocking neutrophil influx protects alveolar development and improves lung function in part by preventing reactive oxygen/nitrogen species accumulation.
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Affiliation(s)
- Lingjie Liao
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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18
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Oh J, Diaz T, Wei B, Chang H, Noda M, Stetler-Stevenson WG. TIMP-2 upregulates RECK expression via dephosphorylation of paxillin tyrosine residues 31 and 118. Oncogene 2006; 25:4230-4. [PMID: 16491114 PMCID: PMC1502148 DOI: 10.1038/sj.onc.1209444] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Revised: 01/10/2006] [Accepted: 01/10/2006] [Indexed: 02/07/2023]
Abstract
We previously demonstrated that TIMP-2 increases the association of Crk with C3G and via subsequent activation of Rap1 enhances the expression of RECK, a membrane-anchored MMP inhibitor. In the present study, we investigate the mechanism of how the TIMP-2 signal is transduced from the alpha3beta1 integrin receptor to the Crk-C3G-Rap1 molecular complex. TIMP-2 treatment of human microvascular endothelial cells (hMVECs) increased the phosphorylation levels of Src at Tyr-527, the negative regulatory site, through enhanced association of Src with Csk. This results in the reduction of Src kinase activity and dephosphorylation of paxillin at Tyr-31/118, the target sites for Src kinase phosphorylation and also the binding sites for the downstream effector Crk. Such TIMP-2 effects accompany the disassembly of paxillin-Crk-DOCK180 molecular complex and, in turn, Rac1 inactivation. On the contrary, levels of paxillin-Crk-C3G complex formation are not reduced, rather slightly increased, which is consistent with our previous finding. Therefore, TIMP-2-mediated inhibition of Src kinase activity leads to the signaling switch from Rac1 to Rap1, thereby leading to enhanced RECK expression.
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Affiliation(s)
- J Oh
- Laboratory of Cellular Oncology, Korea University Graduate School of Medicine, Ansan, Gyeonggi do, Korea.
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19
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Pollard SE, Whiteman M, Spencer JPE. Modulation of peroxynitrite-induced fibroblast injury by hesperetin: a role for intracellular scavenging and modulation of ERK signalling. Biochem Biophys Res Commun 2006; 347:916-23. [PMID: 16857166 DOI: 10.1016/j.bbrc.2006.06.153] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2006] [Accepted: 06/24/2006] [Indexed: 12/28/2022]
Abstract
Peroxynitrite is thought to contribute to the progression of many diseases including cardiovascular disease, cancer, and neurodegenerative disorders. We report that pre-treatment of fibroblasts with the citrus flavanone, hesperetin, prior to peroxynitrite exposure protects against peroxynitrite-mediated cytotoxicity. This protection was partially mediated by the intracellular scavenging of peroxynitrite by hesperetin as exposure of fibroblasts to peroxynitrite following hesperetin loading led to the formation of two intracellular nitro-hesperetin derivatives. In addition, protection appeared to be mediated by hesperetin-induced changes in MAP kinase signalling. Exposure of fibroblasts to hesperetin led to concentration-dependent increases in the phosphorylation of ERK1/2 and was observed to restore peroxynitrite-mediated decreases in ERK1/2 phosphorylation. We propose that the protective potential of hesperetin in fibroblasts may be mediated both by intracellular scavenging of peroxynitrite and by modulation of fibroblast signalling.
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Affiliation(s)
- Susan E Pollard
- Molecular Nutrition Group, School of Chemistry, Food Biosciences and Pharmacy, University of Reading, Reading RG6 6AP, UK
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20
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Zolodz MD, Jia M, Liu H, Henderson GN, Stacpoole PW. A GC–MS/MS method for the quantitative analysis of low levels of the tyrosine metabolites maleylacetone, succinylacetone, and the tyrosine metabolism inhibitor dichloroacetate in biological fluids and tissues. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 837:125-32. [PMID: 16713404 DOI: 10.1016/j.jchromb.2006.04.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Revised: 04/12/2006] [Accepted: 04/18/2006] [Indexed: 11/16/2022]
Abstract
We developed a sensitive method to quantitate the tyrosine metabolites maleylacetone (MA) and succinylacetone (SA) and the tyrosine metabolism inhibitor dichloroacetate (DCA) in biological specimens. Accumulation of these metabolites may be responsible for the toxicity observed when exposed to DCA. Detection limits of previous methods are 200 ng/mL (1.2 pmol/microL) (MA) and 2.6 microg/mL (16.5 pmol/microL) (SA) but the metabolites are likely present in lower levels in biological specimens. To increase sensitivity, analytes were extracted from liver, urine, plasma and cultured nerve cells before and after dosing with DCA, derivatized to their pentafluorobenzyl esters, and analyzed via GC-MS/MS.
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Affiliation(s)
- Melissa D Zolodz
- Division of Endocrinology and Metabolism, Department of Medicine, University of Florida, Gainesville, FL 32610, USA
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21
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Gahm C, Danilov A, Holmin S, Wiklund PN, Brundin L, Mathiesen T. Reduced neuronal injury after treatment with NG-nitro-L-arginine methyl ester (L-NAME) or 2-sulfo-phenyl-N-tert-butyl nitrone (S-PBN) following experimental brain contusion. Neurosurgery 2006; 57:1272-81; discussion 1272-81. [PMID: 16331176 DOI: 10.1227/01.neu.0000187317.32529.06] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE Nitric oxide (NO) and oxygen free radicals are implicated in the pathophysiology of traumatic brain injury (TBI). Peroxynitrite formation from NO and superoxide contributes to secondary neuronal injury but the neuroprotective effects of nitric oxide synthase (NOS)-inhibitors have been contradictory. This study was undertaken to examine whether PTtic administration of the (NOS)-inhibitor N-nitro-l-arginine methyl ester (L-NAME), and a combination of L-NAME and the nitrone radical scavenger 2-sulfo-phenyl-N-tert-butyl nitrone (S-PBN) favorable affects neuronal injury in a model of TBI. METHODS A weight-drop model of TBI was used. The animals received L-NAME, S-PBN or a combination of the drugs 15 minutes prothrombin time (PT) and sacrificed after 24 hours or six days. NOS activity was measured by the conversion of L-[U-C]arginine to L-[U-C]citrulline. Peroxynitrite formation, cellular apoptosis, neuronal degeneration and survival were assessed by nitrotyrosine-, TUNEL-, Fluoro-Jade- and NeuN-stainings. RESULTS eNOS and nNOS activity was significantly reduced in animals that received L-NAME alone or the combination with S-PBN. iNOS activity or iNOS immunoreactivity was not affected. All treatments significantly reduced neuronal degeneration and nitrotyrosine immunoreactivity at 24 hours and increased neuronal survival at six days PT. No differences were detected between L-NAME and L-NAME + S-PBN groups. CONCLUSION NO from NOS contributes to secondary neuronal injury in this TBI-model. PTtic treatment does not inhibit early beneficial NO-related effects. L-NAME and S-PBN limit peroxynitrite formation, promoting neuronal survival. The combination of L-NAME and S-PBN was neuroprotective; surprisingly no additive effects were found on nitrotyrosine formation, apoptosis or neuronal survival.
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Affiliation(s)
- Caroline Gahm
- Department of Clinical Neuroscience, Section of Clinical CNS Research, Karolinska Institute, Stockholm, Sweden.
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22
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Gurer-Orhan H, Ercal N, Mare S, Pennathur S, Orhan H, Heinecke J. Misincorporation of free m-tyrosine into cellular proteins: a potential cytotoxic mechanism for oxidized amino acids. Biochem J 2006; 395:277-84. [PMID: 16363993 PMCID: PMC1422773 DOI: 10.1042/bj20051964] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In vitro studies demonstrate that the hydroxyl radical converts L-phenylalanine into m-tyrosine, an unnatural isomer of L-tyrosine. Quantification of m-tyrosine has been widely used as an index of oxidative damage in tissue proteins. However, the possibility that m-tyrosine might be generated oxidatively from free L-phenylalanine that could subsequently be incorporated into proteins as an L-tyrosine analogue has received little attention. In the present study, we demonstrate that free m-tyrosine is toxic to cultured CHO (Chinese-hamster ovary) cells. We readily detected radiolabelled material in proteins isolated from CHO cells that had been incubated with m-[14C]tyrosine, suggesting that the oxygenated amino acid was taken up and incorporated into cellular proteins. m-Tyrosine was detected by co-elution with authentic material on HPLC and by tandem mass spectrometric analysis in acid hydrolysates of proteins isolated from CHO cells exposed to m-tyrosine, indicating that free m-tyrosine was incorporated intact rather than being metabolized to other products that were subsequently incorporated into proteins. Incorporation of m-tyrosine into cellular proteins was sensitive to inhibition by cycloheximide, suggesting that protein synthesis was involved. Protein synthesis using a cell-free transcription/translation system showed that m-tyrosine was incorporated into proteins in vitro by a mechanism that may involve L-phenylalanine-tRNA synthetase. Collectively, these observations indicate that m-tyrosine is toxic to cells by a pathway that may involve incorporation of the oxidized amino acid into proteins. Thus misincorporation of free oxidized amino acids during protein synthesis may represent an alternative mechanism for oxidative stress and tissue injury during aging and disease.
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Affiliation(s)
- Hande Gurer-Orhan
- *Department of Toxicology, University of Hacettepe, Faculty of Pharmacy, 06100, Ankara, Turkey
| | - Nuran Ercal
- †Department of Chemistry, University of Missouri-Rolla, Rolla, MO 65409, U.S.A
| | - Suneetha Mare
- †Department of Chemistry, University of Missouri-Rolla, Rolla, MO 65409, U.S.A
| | | | - Hilmi Orhan
- *Department of Toxicology, University of Hacettepe, Faculty of Pharmacy, 06100, Ankara, Turkey
| | - Jay W. Heinecke
- ‡Department of Medicine, University of Washington, Seattle, WA 98195, U.S.A
- To whom correspondence should be addressed (email )
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23
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Perluigi M, Joshi G, Sultana R, Calabrese V, De Marco C, Coccia R, Butterfield DA. In vivo protection by the xanthate tricyclodecan-9-yl-xanthogenate against amyloid beta-peptide (1-42)-induced oxidative stress. Neuroscience 2006; 138:1161-70. [PMID: 16427207 DOI: 10.1016/j.neuroscience.2005.12.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Revised: 11/23/2005] [Accepted: 12/01/2005] [Indexed: 10/25/2022]
Abstract
Considerable evidence supports the role of oxidative stress in the pathogenesis of Alzheimer's disease. One hallmark of Alzheimer's disease is the accumulation of amyloid beta-peptide, which invokes a cascade of oxidative damage to neurons that can eventually result in neuronal death. Amyloid beta-peptide is the main component of senile plaques and generates free radicals ultimately leading to neuronal damage of membrane lipids, proteins and nucleic acids. Therefore, interest in the protective role of different antioxidant compounds has been growing for treatment of Alzheimer's disease and other oxidative stress-related disorders. Among different antioxidant drugs, much interest has been devoted to "thiol-delivering" compounds. Tricyclodecan-9-yl-xanthogenate is an inhibitor of phosphatidylcholine specific phospholipase C, and recent studies reported its ability to act as a glutathione-mimetic compound. In the present study, we investigate the in vivo ability of tricyclodecan-9-yl-xanthogenate to protect synaptosomes against amyloid beta-peptide-induced oxidative stress. Gerbils were injected i.p. with tricyclodecan-9-yl-xanthogenate or with saline solution, and synaptosomes were isolated from the brain. Synaptosomal preparations isolated from tricyclodecan-9-yl-xanthogenate injected gerbils and treated ex vivo with amyloid beta-peptide (1-42) showed a significant decrease of oxidative stress parameters: reactive oxygen species levels, protein oxidation (protein carbonyl and 3-nitrotyrosine levels) and lipid peroxidation (4-hydroxy-2-nonenal levels). Our results are consistent with the hypothesis that modulation of free radicals generated by amyloid beta-peptide might represent an efficient therapeutic strategy for treatment of Alzheimer's disease and other oxidative-stress related disorders. Based on the above data, we suggest that tricyclodecan-9-yl-xanthogenate is a potent antioxidant and could be of importance for the treatment of Alzheimer's disease and other oxidative stress-related disorders.
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Affiliation(s)
- M Perluigi
- Department of Biochemical Sciences, University of Rome La Sapienza, Rome 00185, Italy
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24
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Lee SYH, Munerol B, Pollard S, Youdim KA, Pannala AS, Kuhnle GGC, Debnam ES, Rice-Evans C, Spencer JPE. The reaction of flavanols with nitrous acid protects against N-nitrosamine formation and leads to the formation of nitroso derivatives which inhibit cancer cell growth. Free Radic Biol Med 2006; 40:323-34. [PMID: 16413414 DOI: 10.1016/j.freeradbiomed.2005.08.031] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2005] [Revised: 08/16/2005] [Accepted: 08/18/2005] [Indexed: 01/24/2023]
Abstract
Studies have suggested that diets rich in polyphenols such as flavonoids may lead to a reduced risk of gastrointestinal cancers. We demonstrate the ability of monomeric and dimeric flavanols to scavenge reactive nitrogen species derived from nitrous acid. Both epicatechin and dimer B2 (epicatechin dimer) inhibited nitrous acid-induced formation of 3-nitrotyrosine and the formation of the carcinogenic N-nitrosamine, N-nitrosodimethylamine. The reaction of monomeric and dimeric epicatechin with nitrous acid led to the formation of mono- and di-nitroso flavanols, whereas the reaction with hesperetin resulted primarily in the formation of nitrated products. Although, epicatechin was transferred across the jejunum of the small intestine yielding metabolites, its nitroso form was not absorbed. Dimer B2 but not epicatechin monomer inhibited the proliferation of, and triggered apoptosis in, Caco-2 cells. The latter was accompanied by caspase-3 activation and reductions in Akt phosphorylation, suggesting activation of apoptosis via inhibition of prosurvival signaling. Furthermore, the dinitroso derivative of dimer B2, and to a lesser extent the dinitroso-epicatechin, also induced significant toxic effects in Caco-2 cells. The inhibitory effects on cellular proliferation were paralleled by early inhibition of ERK 1/2 phosphorylation and later reductions in cyclin D1 levels, indicating modulation of cell cycle regulation in Caco-2 cells. These effects highlight multiple routes in which dietary derived flavanols may exert beneficial effects in the gastrointestinal tract.
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Affiliation(s)
- Stephanie Y H Lee
- Molucular Nutrition Group, School of Biosciences, University of Reading, Reading RG2 6AP, UK
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25
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McGargill MA, Sharp LL, Bui JD, Hedrick SM, Calbo S. Active Ca2+/calmodulin-dependent protein kinase II gamma B impairs positive selection of T cells by modulating TCR signaling. J Immunol 2005; 175:656-64. [PMID: 16002660 DOI: 10.4049/jimmunol.175.2.656] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
T cell development is regulated at two critical checkpoints that involve signaling events through the TCR. These signals are propagated by kinases of the Src and Syk families, which activate several adaptor molecules to trigger Ca(2+) release and, in turn, Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) activation. In this study, we show that a constitutively active form of CaMKII antagonizes TCR signaling and impairs positive selection of thymocytes in mice. Following TCR engagement, active CaMKII decreases TCR-mediated CD3zeta chain phosphorylation and ZAP70 recruitment, preventing further downstream events. Therefore, we propose that CaMKII belongs to a negative-feedback loop that modulates the strength of the TCR signal through the tyrosine phosphatase Src homology 2 domain-containing phosphatase 2 (SHP-2).
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MESH Headings
- Animals
- CD3 Complex/metabolism
- Calcium/metabolism
- Calcium/physiology
- Calcium-Calmodulin-Dependent Protein Kinase Type 2
- Calcium-Calmodulin-Dependent Protein Kinases/biosynthesis
- Calcium-Calmodulin-Dependent Protein Kinases/genetics
- Calcium-Calmodulin-Dependent Protein Kinases/physiology
- Cell Differentiation/genetics
- Cell Differentiation/immunology
- Cell Line, Tumor
- Female
- Humans
- Intracellular Fluid/enzymology
- Intracellular Fluid/metabolism
- Intracellular Signaling Peptides and Proteins/metabolism
- Isoenzymes/biosynthesis
- Isoenzymes/genetics
- Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/genetics
- Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Phosphorylation
- Protein Phosphatase 2
- Protein Tyrosine Phosphatase, Non-Receptor Type 11
- Protein Tyrosine Phosphatases/metabolism
- Receptors, Antigen, T-Cell/antagonists & inhibitors
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell/physiology
- SH2 Domain-Containing Protein Tyrosine Phosphatases
- Signal Transduction/genetics
- Signal Transduction/immunology
- T-Lymphocyte Subsets/cytology
- T-Lymphocyte Subsets/enzymology
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Tyrosine/antagonists & inhibitors
- Tyrosine/metabolism
- src Homology Domains/genetics
- src Homology Domains/immunology
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Affiliation(s)
- Maureen A McGargill
- Department of Biology and Cancer Center, University of California-San Diego, La Jolla, CA 92093, USA
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26
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Ho LJ, Hung LF, Weng CY, Wu WL, Chou P, Lin YL, Chang DM, Tai TY, Lai JH. Dengue virus type 2 antagonizes IFN-alpha but not IFN-gamma antiviral effect via down-regulating Tyk2-STAT signaling in the human dendritic cell. J Immunol 2005; 174:8163-72. [PMID: 15944325 DOI: 10.4049/jimmunol.174.12.8163] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The immunopathogenesis mechanism of dengue virus (DV) infection remains elusive. We previously showed that the target of DV in humans is dendritic cells (DCs), the primary sentinels of immune system. We also observed that despite the significant amount of IFN-alpha induced; DV particles remain massively produced from infected DCs. It suggests that DV may antagonize the antiviral effect of IFN-alpha. Recent work in animal studies demonstrated the differential critical roles of antiviral cytokines, namely IFN-alpha/IFN-beta and IFN-gamma, in blocking early viral production and in preventing viral-mediated disease, respectively. In this study, we examined the effects of IFN-alpha and IFN-gamma in DV infection of monocyte-derived DCs. We showed that the preinfection treatment with either IFN-alpha or IFN-gamma effectively armed DCs and limited viral production in infected cells. However, after infection, DV developed mechanisms to counteract the protection from lately added IFN-alpha, but not IFN-gamma. Such a selective antagonism on antiviral effect of IFN-alpha, but not IFN-gamma, correlated with down-regulated tyrosine-phosphorylation and DNA-binding activities of STAT1 and STAT3 transcription factors by DV. Furthermore, subsequent studies into the underlying mechanisms revealed that DV attenuated IFN-alpha-induced tyrosine-phosphorylation of Tyk2, an upstream molecule of STAT activation, but had no effect on expression of both IFN-alpha receptor 1 and IFN-alpha receptor 2. Moreover, DV infection by itself could activate STAT1 and STAT3 through IFN-alpha-dependent and both IFN-alpha-dependent and IFN-alpha-independent mechanisms, respectively. These observations provide very useful messages with physiological significance in investigation of the pathogenesis, the defense mechanisms of human hosts and the therapeutic considerations in DV infection.
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Affiliation(s)
- Ling-Jun Ho
- Division of Gerontology Research, National Health Research Institute, Academia Sinica, Taipei, Taiwan
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Zhang M, Moran M, Round J, Low TA, Patel VP, Tomassian T, Hernandez JD, Miceli MC. CD45 Signals outside of Lipid Rafts to Promote ERK Activation, Synaptic Raft Clustering, and IL-2 Production. J Immunol 2005; 174:1479-90. [PMID: 15661907 DOI: 10.4049/jimmunol.174.3.1479] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CD45 is dynamically repositioned within lipid rafts and the immune synapse during T cell activation, although the molecular consequences of CD45 repositioning remain unclear. In this study we examine the role of CD45 membrane compartmentalization in regulating murine T cell activation. We find that raft-localized CD45 antagonizes IL-2 production by opposing processive TCR signals, whereas raft-excluded CD45 promotes ERK-dependent polarized synaptic lipid raft clustering and IL-2 production. We propose that these dual CD45 activities ensure that only robust TCR signals proceed, whereas signals meeting threshold requirements are potentiated. Our findings highlight membrane compartmentalization as a key regulator of CD45 function and elucidate a novel signal transduction pathway by which raft-excluded CD45 positively regulates T cell activation.
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MESH Headings
- Adaptor Proteins, Signal Transducing/antagonists & inhibitors
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Animals
- Cell Line
- Cell Line, Tumor
- Down-Regulation/immunology
- Enzyme Activation/immunology
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Humans
- Hybridomas
- Interleukin-2/antagonists & inhibitors
- Interleukin-2/biosynthesis
- Leukocyte Common Antigens/biosynthesis
- Leukocyte Common Antigens/genetics
- Leukocyte Common Antigens/physiology
- Lymphocyte Activation/genetics
- Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/genetics
- Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/metabolism
- Membrane Microdomains/enzymology
- Membrane Microdomains/immunology
- Membrane Microdomains/metabolism
- Membrane Proteins/antagonists & inhibitors
- Membrane Proteins/genetics
- Membrane Proteins/metabolism
- Mice
- Phosphoproteins/antagonists & inhibitors
- Phosphoproteins/genetics
- Phosphoproteins/metabolism
- Phosphorylation
- Receptors, Antigen, T-Cell/genetics
- Receptors, Antigen, T-Cell/metabolism
- Receptors, Antigen, T-Cell/physiology
- Recombinant Fusion Proteins/genetics
- Recombinant Fusion Proteins/metabolism
- Signal Transduction/genetics
- Signal Transduction/immunology
- Son of Sevenless Proteins/genetics
- Son of Sevenless Proteins/metabolism
- T-Lymphocytes/enzymology
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Tyrosine/antagonists & inhibitors
- Tyrosine/metabolism
- Up-Regulation/immunology
- src Homology Domains/genetics
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Affiliation(s)
- Min Zhang
- Department of Microbiology, University of California School of Medicine, Los Angeles, CA 90095, USA
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Prabhakar S, Qiao Y, Canova A, Tse DB, Pine R. IFN-αβ Secreted during Infection Is Necessary but Not Sufficient for Negative Feedback Regulation of IFN-αβ Signaling byMycobacterium tuberculosis. J Immunol 2005; 174:1003-12. [PMID: 15634924 DOI: 10.4049/jimmunol.174.2.1003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
IFN-alphabeta functions in the transition from innate to adaptive immunity and may impinge on the interaction of Mycobacterium tuberculosis with its host. Infection by M. tuberculosis causes IFN-alphabeta secretion and down-regulation of IFN-alphabeta signaling in human APC and the human monocytic cell line THP-1, which provides a model for these studies. Neutralization of secreted IFN-alphabeta prevents inhibition of IFN-alpha signaling during infection, but several lines of evidence distinguish inhibition due to infection from a negative feedback response to only IFN-alphabeta. First, greater inhibition of IFN-alpha-stimulated STAT-1 tyrosine phosphorylation occurs 3 days postinfection than 1 or 3 days after IFN-alphabeta pretreatment. Second, LPS also induces IFN-alphabeta secretion and causes IFN-alphabeta-dependent down-regulation of IFN-alpha signaling, yet the inhibition differs from that caused by infection. Third, IFN-alpha signaling is inhibited when cells are grown in conditioned medium collected from infected cells 1 day postinfection, but not if it is collected 3 days postinfection. Because IFN-alphabeta is stable, the results with conditioned medium suggest the involvement of an additional, labile substance during infection. Further characterizing signaling for effects of infection, we found that cell surface IFN-alphabeta receptor is not reduced by infection, but that infection increases association of protein tyrosine phosphatase 1c with the receptor and with tyrosine kinase 2. Concomitantly, IFN-alpha stimulation of tyrosine kinase 2 tyrosine phosphorylation and kinase activity decreases in infected cells. Moreover, infection reduces the abundance of JAK-1 and tyrosine-phosphorylated JAK-1. Thus, the distinctive down-regulation of IFN-alpha signaling by M. tuberculosis occurs together with a previously undescribed combination of inhibitory intracellular events.
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Sommerfeld MR, Metzger S, Stosik M, Tennagels N, Eckel J. In vitro phosphorylation of insulin receptor substrate 1 by protein kinase C-zeta: functional analysis and identification of novel phosphorylation sites. Biochemistry 2004; 43:5888-901. [PMID: 15134463 DOI: 10.1021/bi049640v] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein kinase C-zeta (PKC-zeta) participates both in downstream insulin signaling and in the negative feedback control of insulin action. Here we used an in vitro approach to identify PKC-zeta phosphorylation sites within insulin receptor substrate 1 (IRS-1) and to characterize the functional implications. A recombinant IRS-1 fragment (rIRS-1(449)(-)(664)) containing major tyrosine motifs for interaction with phosphatidylinositol (PI) 3-kinase strongly associated to the p85alpha subunit of PI 3-kinase after Tyr phosphorylation by the insulin receptor. Phosphorylation of rIRS-1(449)(-)(664) by PKC-zeta induced a prominent inhibition of this process with a mixture of classical PKC isoforms being less effective. Both PKC-zeta and the classical isoforms phosphorylated rIRS-1(449)(-)(664) on Ser(612). However, modification of this residue did not reduce the affinity of p85alpha binding to pTyr-containing peptides (amino acids 605-615 of rat IRS-1), as determined by surface plasmon resonance. rIRS-1(449)(-)(664) was then phosphorylated by PKC-zeta using [(32)P]ATP and subjected to tryptic phosphopeptide mapping based on two-dimensional HPLC coupled to mass spectrometry. Ser(498) and Ser(570) were identified as novel phosphoserine sites targeted by PKC-zeta. Both sites were additionally confirmed by phosphopeptide mapping of the corresponding Ser --> Ala mutants of rIRS-1(449)(-)(664). Ser(570) was specifically targeted by PKC-zeta, as shown by immunoblotting with a phosphospecific antiserum against Ser(570) of IRS-1. Binding of p85alpha to the S570A mutant was less susceptible to inhibition by PKC-zeta, when compared to the S612A mutant. In conclusion, our in vitro data demonstrate a strong inhibitory action of PKC-zeta at the level of IRS-1/PI 3-kinase interaction involving multiple serine phosphorylation sites. Whereas Ser(612) appears not to participate in the negative control of insulin signaling, Ser(570) may at least partly contribute to this process.
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Affiliation(s)
- Mark R Sommerfeld
- Department of Clinical Biochemistry and Pathobiochemistry, German Diabetes Research Institute, Germany
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30
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Ernst NMSKJ, Suryapranata H, Miedema K, Slingerland RJ, Ottervanger JP, Hoorntje JCA, Gosselink ATM, Dambrink JHE, de Boer MJ, Zijlstra F, van 't Hof AWJ. Achieved platelet aggregation inhibition after different antiplatelet regimens during percutaneous coronary intervention for ST-segment elevation myocardial infarction. J Am Coll Cardiol 2004; 44:1187-93. [PMID: 15364318 DOI: 10.1016/j.jacc.2004.06.050] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2004] [Revised: 05/13/2004] [Accepted: 06/07/2004] [Indexed: 11/17/2022]
Abstract
OBJECTIVES To evaluate the extent of platelet aggregation inhibition in patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI), treated with different antiplatelet agents and dosages. BACKGROUND The extent of platelet aggregation inhibition is an independent predictor of major cardiac events after elective PCI. In STEMI patients undergoing PCI, routine dose of antiplatelet agents may be associated with less effective platelet aggregation inhibition. METHODS Patients were treated with clopidogrel before angiography and randomized to abciximab, tirofiban, high-dose tirofiban, or no glycoprotein (GP) IIb/IIIa inhibitor; GP IIb/IIIa inhibitor bolus, followed by maintenance infusion, was administered after angiography, but before PCI. Platelet aggregation inhibition was assessed before angiography, immediately after PCI, and 1 and 6 h afterwards. RESULTS The total study population consisted of 112 patients. Platelet aggregation inhibition was variable for individuals and suboptimal for all agents, particularly in the periprocedural period. Only with high-dose tirofiban, mean periprocedural platelet aggregation inhibition exceeded 80%. Angiographic parameters after PCI were not different between the groups. No relationship was found between the level of platelet aggregation and parameters of PCI success (Thrombolysis In Myocardial Infarction frame count and myocardial blush grade), after combining the data from all four groups studied. CONCLUSIONS Platelet aggregation inhibition in STEMI patients undergoing PCI, treated with antiplatelet agents, is variable and suboptimal for all agents and dosages studied. Only with high-dose tirofiban, mean periprocedural platelet aggregation inhibition exceeded 80%. However, no relationship of platelet aggregation inhibition and angiographic outcome was found in this patient cohort.
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31
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Morrison AC, Wilson CB, Ray M, Correll PH. Macrophage-stimulating protein, the ligand for the stem cell-derived tyrosine kinase/RON receptor tyrosine kinase, inhibits IL-12 production by primary peritoneal macrophages stimulated with IFN-gamma and lipopolysaccharide. J Immunol 2004; 172:1825-32. [PMID: 14734766 DOI: 10.4049/jimmunol.172.3.1825] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
IL-12, produced by APCs during the initial stages of an immune response, plays a pivotal role in the induction of IFN-gamma by NK and gammadeltaT cells and in driving the differentiation of Th1 cells, thus providing a critical link between innate and acquired immunity. Due to the unique position occupied by IL-12 in the regulation of immunity, many mechanisms have evolved to modulate IL-12 production. We have shown previously that macrophage-stimulating protein (MSP), the ligand for the stem cell-derived tyrosine kinase/recepteur d'origine nantais (RON) receptor, inhibits NO production by macrophages in response to IFN-gamma and enhances the expression of arginase. Mice lacking RON exhibit increased inflammation in a delayed-type hypersensitivity reaction and increased susceptibility to endotoxic shock. In this study we demonstrate that pretreatment of macrophages with MSP before IFN-gamma and LPS results in the complete inhibition of IL-12 production due to suppression of p40 expression. This response is mediated by the RON receptor, and splenocytes from RON(-/-) animals produce increased levels of IFN-gamma. MSP pretreatment of macrophages resulted in decreased tyrosine phosphorylation of Stat-1 and decreased expression of IFN consensus sequence binding protein in response to inflammatory cytokines. In addition to IL-12, the expression of IL-15 and IL-18, cytokines that are also dependent on IFN consensus sequence binding protein activation, is inhibited by pretreatment with MSP before IFN-gamma and LPS. We also show that the ability of MSP to inhibit IL-12 production is independent of IL-10. Taken together, these results suggest that MSP may actively suppress cell-mediated immune responses through its ability to down-regulate IL-12 production and thus inhibit classical activation of macrophages.
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Affiliation(s)
- Amy C Morrison
- Department of Veterinary Science, Graduate Program in Biochemistry, Microbiology, and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA
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32
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Di Paola R, Genovese T, Caputi AP, Threadgill M, Thiemermann C, Cuzzocrea S. Beneficial effects of 5-aminoisoquinolinone, a novel, potent, water-soluble, inhibitor of poly (ADP-ribose) polymerase, in a rat model of splanchnic artery occlusion and reperfusion. Eur J Pharmacol 2004; 492:203-10. [PMID: 15178366 DOI: 10.1016/j.ejphar.2004.03.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2003] [Revised: 03/04/2004] [Accepted: 03/17/2004] [Indexed: 11/24/2022]
Abstract
Poly(ADP-ribose) polymerase (PARP), a nuclear enzyme activated by strand breaks in DNA, plays an important role in the tissue injury associated with ischemia-reperfusion and inflammation. Splanchnic artery occlusion and reperfusion causes an enhanced formation of reactive oxygen species which contribute to the pathophysiology of shock. The aim of the present study was to investigate the effects of 5-aminoisoquinolinone (5-AIQ), a potent water-soluble inhibitor of poly(ADP-ribose) polymerase (PARP), in the pathogenesis of splanchnic artery occlusion shock. Splanchnic artery occlusion shock was induced in rats by clamping both the superior mesenteric artery and the celiac artery for 45 min, followed thereafter by release of the clamp (reperfusion). At 60 min after reperfusion, all animals were sacrificed for histological examination and biochemical studies. Treatment of rats with 5-AIQ (3 mg/kg i.v.), attenuated the fall of mean arterial blood pressure caused by splanchnic artery occlusion shock. 5-AIQ also attenuated the ileum injury as well as the increase in the tissue levels of myeloperoxidase and malondialdehyde caused by splanchnic artery occlusion shock in the ileum. The immunohistochemical examination also demonstrated a marked increase in the immunoreactivity to PAR, nitrotyrosine, and intercellular adhesion molecule (ICAM-1) in the necrotic ileum from splanchnic artery occlusion-shocked rats. 5-AIQ treatment significantly reduced the increase of positive staining for PAR, nitrotyrosine and ICAM-I. In conclusion, these results show that 5-AIQ, a new water-soluble potent inhibitor of poly(ADP-ribose) polymerase, exerts multiple protective effects in splanchnic artery occlusion/reperfusion shock.
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Affiliation(s)
- Rosanna Di Paola
- Department of Clinical and Experimental Medicine and Pharmacology, School of Medicine, University of Messina, via C. Valeria, Torre Biologica, Policlinico Universitario, 98123 Messina, Italy
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Bamm VV, Tsemakhovich VA, Shaklai M, Shaklai N. Haptoglobin Phenotypes Differ in Their Ability To Inhibit Heme Transfer from Hemoglobin to LDL†. Biochemistry 2004; 43:3899-906. [PMID: 15049697 DOI: 10.1021/bi0362626] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
LDL oxidation plays a pivotal role in atherosclerosis. Excellular hemoglobin (Hb) is a trigger of LDL oxidation. By virtue of its ability to bind hemoglobin, haptoglobin (Hp) serves as an antioxidant. Oxidation of LDL by hemoglobin was analyzed to occur by heme displacement from methemoglobin lodged in LDL. The LDL-associated heme is disintegrated, and iron inserted this way in LDL triggers formation of lipid peroxides. The genetic polymorphism of haptoglobin was found to be a risk factor in the pathogenesis of atherosclerosis. Individuals with Hp2-2 have more vascular incidences as compared to those with Hp1-1. In the current study, oxidation of LDL by metHb was carried out at physiological pH without addition of external peroxides. Hb-derived oxidation of lipids and protein was found to be practically inhibited by Hp1-1 but only partially by Hp2-2. Heme transfer from metHb to LDL was almost completely omitted by Hp1-1 and only partially by Hp2-2. We concluded that partial heme transfer from the Hb-Hp2-2 complex to LDL is the reason for oxidation of LDL lipids as well as protein. These findings provide a molecular basis for Hp2-2 atherogenic properties.
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Affiliation(s)
- Vladimir V Bamm
- Department of Human Genetics and Molecular Medicine, Sackler Institute of Molecular Medicine, Tel Aviv University, 69978 Tel-Aviv, Israel
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34
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Bezerra MM, Brain SD, Greenacre S, Jerônimo SMB, de Melo LB, Keeble J, da Rocha FAC. Reactive nitrogen species scavenging, rather than nitric oxide inhibition, protects from articular cartilage damage in rat zymosan-induced arthritis. Br J Pharmacol 2004; 141:172-82. [PMID: 14662723 PMCID: PMC1574182 DOI: 10.1038/sj.bjp.0705600] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2003] [Revised: 10/02/2003] [Accepted: 10/28/2003] [Indexed: 01/22/2023] Open
Abstract
1. The contribution of nitric oxide (NO) and peroxynitrite (PN) to inflammation in a zymosan-induced (1 mg, intra-articular, i.art.) rat model of arthritis was assessed by histopathology and by measuring the glycosaminoglycan (GAG) content of the articular cartilage. 2. Progression of the chronic synovitis in zymosan-induced arthritis (ZYA) was associated with increased nitrite and nitrotyrosine (3-NT) levels in the joint exudates that paralleled a progressive loss of the GAG content. An increase in 3-NT was also observed after i.art. PN. 3. The nonselective nitric oxide synthase (NOS) inhibitor l-N(G)-nitroarginine methyl ester (25-75 mg x kg(-1)day(-1)) or the selective inducible NOS inhibitor aminoguanidine (50-100 mg x kg(-1)day(-1)) given 1 h before (prophylactic) or 3 days after (therapeutic) injection of the zymosan ameliorated the synovitis, but worsened the GAG loss, as measured at the end of the experiment (day 7). 4. The PN scavenger uric acid (100-250 mg x kg(-1) i.p. four times daily) given prophylactically until the end of the experiment (day 14), in a dose compatible with its PN scavenging activity, significantly decreased both the synovitis and the GAG loss. 5. In conclusion, PN formation is associated with cartilage damage in addition to proinflammatory activity in ZYA. NOS inhibitors and a PN scavenger were able to reduce the cellular infiltration, while displaying opposite effects on cartilage homeostasis either by enhancing or ameliorating the damage, respectively.
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Affiliation(s)
- Mirna Marques Bezerra
- Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceará, Fortaleza, Brazil
| | - Susan D Brain
- Centre for Cardiovascular Biology & Medicine, New Hunt's House, King's College London, Guy's Campus, London SE1 1UL
| | - Stan Greenacre
- Centre for Cardiovascular Biology & Medicine, New Hunt's House, King's College London, Guy's Campus, London SE1 1UL
| | | | - Liana Batista de Melo
- Department of Biochemistry, Federal University of Rio Grande do Norte, Natal, Brazil
| | - Julie Keeble
- Centre for Cardiovascular Biology & Medicine, New Hunt's House, King's College London, Guy's Campus, London SE1 1UL
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Zingarelli B, Sheehan M, Hake PW, O'Connor M, Denenberg A, Cook JA. Peroxisome Proliferator Activator Receptor-γ Ligands, 15-Deoxy-Δ12,14-Prostaglandin J2 and Ciglitazone, Reduce Systemic Inflammation in Polymicrobial Sepsis by Modulation of Signal Transduction Pathways. J Immunol 2003; 171:6827-37. [PMID: 14662889 DOI: 10.4049/jimmunol.171.12.6827] [Citation(s) in RCA: 160] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Peroxisome proliferator activator receptor-gamma (PPARgamma) is a nuclear receptor that controls the expression of several genes involved in metabolic homeostasis. We investigated the role of PPARgamma during the inflammatory response in sepsis by the use of the PPARgamma ligands, 15-deoxy-Delta(12,14)-PGJ(2) (15d-PGJ(2)) and ciglitazone. Polymicrobial sepsis was induced by cecal ligation and puncture in rats and was associated with hypotension, multiple organ failure, and 50% mortality. PPARgamma expression was markedly reduced in lung and thoracic aorta after sepsis. Immunohistochemistry showed positive staining for nitrotyrosine and poly(ADP-ribose) synthetase in thoracic aortas. Plasma levels of TNF-alpha, IL-6, and IL-10 were increased. Elevated activity of myeloperoxidase was found in lung, colon, and liver, indicating a massive infiltration of neutrophils. These events were preceded by degradation of inhibitor kappaBalpha (IkappaBalpha), activation of IkappaB kinase complex, and c-Jun NH(2)-terminal kinase and, subsequently, activation of NF-kappaB and AP-1 in the lung. In vivo treatment with ciglitazone or 15d-PGJ(2) ameliorated hypotension and survival, blunted cytokine production, and reduced neutrophil infiltration in lung, colon, and liver. These beneficial effects of the PPARgamma ligands were associated with the reduction of IkappaB kinase complex and c-Jun NH(2)-terminal kinase activation and the reduction of NF-kappaB and AP-1 DNA binding in the lung. Furthermore, treatment with ciglitazone or 15d-PGJ(2) up-regulated the expression of PPARgamma in lung and thoracic aorta and abolished nitrotyrosine formation and poly(ADP-ribose) expression in aorta. Our data suggest that PPARgamma ligands attenuate the inflammatory response in sepsis through regulation of the NF-kappaB and AP-1 pathways.
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Affiliation(s)
- Basilia Zingarelli
- Division of Critical Care, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
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36
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Dráberová L, Dudková L, Boubelík M, Tolarová H, Smíd F, Dráber P. Exogenous Administration of Gangliosides Inhibits FcεRI-Mediated Mast Cell Degranulation by Decreasing the Activity of Phospholipase Cγ. J Immunol 2003; 171:3585-93. [PMID: 14500655 DOI: 10.4049/jimmunol.171.7.3585] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Gangliosides released from tumor cells, as well as administered exogenously, suppress the immune responses by largely unknown mechanisms. We show here that a pretreatment of rat basophilic leukemia cells with isolated brain gangliosides inhibited the release of preformed secretory mediators from cells activated via FcepsilonRI but not Thy-1 glycoprotein. Exogenously administered gangliosides also affected the cell-substrate adhesion and the levels of polymeric filamentous actin in Ag-activated cells. Although the production of phosphoinositides was also decreased, enzymatic activity of phosphatidylinositol 3-kinase was not inhibited. Gangliosides had no or only marginal effect on the association of aggregated FcepsilonRI with glycosphingolipid-enriched membranes and on tyrosine phosphorylation of FcepsilonRI and the linker for activation of T cells. Though pretreatment with gangliosides did not inhibit the association of linker for activation of T cells with phospholipase C (PLC)gamma1 and PLCgamma2, tyrosine phosphorylation of these enzymes, as well as their enzymatic activities and association with detergent-insoluble signaling assemblies were reduced. This resulted in a decreased production of inositol 1,4,5-trisphosphate and an inhibition of Ca(2+) mobilization. The combined data support the concept that exogenously administered gangliosides interfere with those properties of glycosphingolipid-enriched membranes that are important for the formation of plasma membrane-associated signaling assemblies containing PLCgamma but not for initial tyrosine phosphorylation of FcepsilonRI subunits.
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Affiliation(s)
- Lubica Dráberová
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
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37
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Cuzzocrea S, Pisano B, Dugo L, Ianaro A, Patel NSA, Paola RD, Genovese T, Chatterjee PK, Rosa MD, Caputi AP, Thiemermann C. Rosiglitazone and 15-deoxy-Delta12,14-prostaglandin J2, ligands of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma), reduce ischaemia/reperfusion injury of the gut. Br J Pharmacol 2003; 140:366-76. [PMID: 12970094 PMCID: PMC1574022 DOI: 10.1038/sj.bjp.0705419] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. The peroxisome proliferator-activated receptor-gamma (PPAR-gamma) is a member of the nuclear receptor superfamily of ligand-dependent transcription factors related to retinoid, steroid and thyroid hormone receptors. The thiazolidinedione rosiglitazone and the endogenous cyclopentenone prostaglandin (PG)D2 metabolite, 15-deoxy-Delta12,14-PGJ2 (15d-PGJ2), are two PPAR-gamma ligands, which modulate the transcription of target genes. 2. The aim of this study was to investigate the effect of rosiglitazone and 15d-PGJ2 on the tissue injury caused by ischaemia/reperfusion (I/R) of the gut. 3. I/R injury of the intestine was caused by clamping both the superior mesenteric artery and the coeliac trunk for 45 min, followed by release of the clamp allowing reperfusion for 2 or 4 h. This procedure results in splanchnic artery occlusion (SAO) shock. 4. Rats subjected to SAO developed a significant fall in mean arterial blood pressure, and only 10% of the animals survived for the entire 4 h reperfusion period. Surviving animals were killed for histological examination and biochemical studies. Rats subjected to SAO displayed a significant increase in tissue myeloperoxidase (MPO) activity and malondialdehyde (MDA) levels, significant increases in plasma tumour necrosis factor (TNF)-alpha and interleukin (IL)-1beta levels and marked injury to the distal ileum. 5. Increased immunoreactivity to nitrotyrosine was observed in the ileum of rats subjected to SAO. Staining of sections of the ileum obtained from SAO rats with anti-intercellular adhesion molecule (ICAM-1) antibody resulted in diffuse staining. 6. Administration at 30 min prior to the onset of gut ischaemia of the two PPAR-gamma agonists (rosiglitazone (0.3 mg kg-1 i.v.) and 15d-PGJ2 (0.3 mg kg-1 i.v.)) significantly reduced the (i) fall in mean arterial blood pressure, (ii) mortality rate, (iii) infiltration of the reperfused intestine with polymorphonuclear neutrophils (MPO activity), (iv) lipid peroxidation (MDA levels), (v) production of proinflammatory cytokines (TNF-alpha and IL-1beta) and (vi) histological evidence of gut injury. Administration of rosiglitazone and 15d-PGJ2 also markedly reduced the nitrotyrosine formation and the upregulation of ICAM-1 during reperfusion. 7. In order to elucidate whether the protective effects of rosiglitazone and 15d-PGJ2 are related to the activation of the PPAR-gamma receptor, we also investigated the effect of a PPAR-gamma antagonist, bisphenol A diglycidyl ether (BADGE), on the protective effects of rosiglitazone and 15d-PGJ2. BADGE (1 mg kg-1 administered i.v. 30 min prior to the treatment of rosiglitazone or 15d-PGJ2) significantly antagonised the effect of the two PPAR-gamma agonists and thus abolished the protective effect against gut I/R. 8. These results demonstrate that the two PPAR-gamma agonists, rosiglitazone and 15d-PGJ2, significantly reduce I/R injury of the intestine.
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Affiliation(s)
- Salvatore Cuzzocrea
- Department of Clinical and Experimental Medicine and Pharmacology, Torre Biologica, Policlinico Universitario, 98123 Messina, Italy
- Author for correspondence:
| | - Barbara Pisano
- Department of Experimental Pharmacology, University of Naples Federico II, Italy
| | - Laura Dugo
- Department of Clinical and Experimental Medicine and Pharmacology, Torre Biologica, Policlinico Universitario, 98123 Messina, Italy
| | - Angela Ianaro
- Department of Experimental Pharmacology, University of Naples Federico II, Italy
| | - Nimesh S A Patel
- Department of Experimental Medicine & Nephrology, The William Harvey Research Institute, St Bartholomew's and The Royal London School of Medicine and Dentistry, Charterhouse Square, London EC1M 6BQ
| | - Rosanna Di Paola
- Department of Clinical and Experimental Medicine and Pharmacology, Torre Biologica, Policlinico Universitario, 98123 Messina, Italy
| | - Tiziana Genovese
- Department of Clinical and Experimental Medicine and Pharmacology, Torre Biologica, Policlinico Universitario, 98123 Messina, Italy
| | - Prabal K Chatterjee
- Department of Experimental Medicine & Nephrology, The William Harvey Research Institute, St Bartholomew's and The Royal London School of Medicine and Dentistry, Charterhouse Square, London EC1M 6BQ
| | - Massimo Di Rosa
- Department of Experimental Pharmacology, University of Naples Federico II, Italy
| | - Achille P Caputi
- Department of Clinical and Experimental Medicine and Pharmacology, Torre Biologica, Policlinico Universitario, 98123 Messina, Italy
| | - Christoph Thiemermann
- Department of Experimental Medicine & Nephrology, The William Harvey Research Institute, St Bartholomew's and The Royal London School of Medicine and Dentistry, Charterhouse Square, London EC1M 6BQ
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Ceponis PJM, McKay DM, Menaker RJ, Galindo-Mata E, Jones NL. Helicobacter pylori infection interferes with epithelial Stat6-mediated interleukin-4 signal transduction independent of cagA, cagE, or VacA. J Immunol 2003; 171:2035-41. [PMID: 12902508 DOI: 10.4049/jimmunol.171.4.2035] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Helicobacter pylori is a bacterial pathogen evolved to chronically colonize the gastric epithelium, evade immune clearance by the host, and cause gastritis, peptic ulcers, and even gastric malignancies in some infected humans. In view of the known ability of this bacterium to manipulate gastric epithelial cell signal transduction cascades, we determined the effects of H. pylori infection on epithelial IL-4-Stat6 signal transduction. HEp-2 and MKN45 epithelial cells were infected with H. pylori strains LC11 or 8823 (type 1; cagA(+)/cagE(+)/VacA(+)), LC20 (type 2; cagA(-), cagE(-), VacA(-)), and cagA, cagE, and vacA isogenic mutants of strain 8823, with some cells receiving subsequent treatment with the Th2 cytokine IL-4, a known Stat6 activator. Immunofluorescence showed a disruption of Stat6-induced nuclear translocation by IL-4 in LC11-infected HEp-2 cells. IL-4-inducible Stat6 DNA binding in HEp-2 and MKN45 cells was abrogated by infection, but MKN45 cell viability was unaffected. A decrease in IL-4-mediated Stat6 tyrosine phosphorylation in nuclear and whole cell lysates was also observed following infection with strains LC11 and LC20, while neither strain altered IL-4 receptor chain alpha or Janus kinase 1 protein expression. Furthermore, parental strain 8823 and its isogenic cagA, cagE, and vacA mutants also suppressed IL-4-induced Stat6 tyrosine phosphorylation to comparable degrees. Thus, H. pylori did not directly activate Stat6, but blocked the IL-4-induced activation of epithelial Stat6. This may represent an evolutionarily conserved strategy to disrupt a Th2 response and evade the host immune system, allowing for successful chronic infection.
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Affiliation(s)
- Peter J M Ceponis
- Research Institute, Hospital for Sick Children, Toronto, Ontario, Canada
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Chen CW, Chang YH, Tsi CJ, Lin WW. Inhibition of IFN-gamma-mediated inducible nitric oxide synthase induction by the peroxisome proliferator-activated receptor gamma agonist, 15-deoxy-delta 12,14-prostaglandin J2, involves inhibition of the upstream Janus kinase/STAT1 signaling pathway. J Immunol 2003; 171:979-88. [PMID: 12847270 DOI: 10.4049/jimmunol.171.2.979] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peroxisome proliferator-activated receptor gamma (PPARgamma) ligands have been reported to exert anti-inflammatory activities in macrophages by competition for transcriptional coactivators with some transcriptional factors, including NF-kappaB. In the present study the influence of PPARgamma activators on IFN-gamma-elicited macrophage stimulation and signaling cascades was investigated. The results show that IFN-gamma-induced inducible NO synthase (iNOS) gene transcription, iNOS protein induction, and NO production are more sensitive to inhibition by 15-deoxy-Delta(12,14)-prostaglandin J(2) (15dPGJ(2)) than by the other two PPARgamma agonists, GW1929 and ciglitazone. Delayed addition of 15dPGJ(2) for 2 h resulted in reduced inhibition, suggesting action by 15dPGJ(2) on the upstream signaling cascades. Immunoblotting, DNA binding, and reporter gene assays consistently revealed the inhibitory ability of 15dPGJ(2), but not GW1929 or ciglitazone, on IFN-gamma-elicited signaling cascades, including tyrosine phosphorylation of Janus tyrosine protein kinase 2 and STAT1, DNA binding, and IFN regulatory factor-1 trans-activation of STAT1. These effects of 15dPGJ(2) were not abrogated by the PPARgamma antagonist, bisphenol A diglycidyl ether, indicating the PPARgamma-independent actions. 15dPGJ(2) also attenuated IL-6-induced tyrosine phosphorylation of STAT1 and STAT3 in Hep3B hepatoma cells. Consistent with the inhibitory effect of reactive oxygen species on STAT1 signaling, STAT1 inhibition by 15dPGJ(2) was abrogated by N-acetylcysteine, glutathione, superoxide dismutase, and catalase. Furthermore, 15dPGJ(2)-induced inhibition of STAT1 phosphorylation and NO production still occurred in the presence of peroxovanadate, ruling out the action mechanism of 15dPGJ(2) on tyrosine phosphatase. Taken together, for the first time in this study we demonstrate that 15dPGJ(2) can inhibit cytokine-stimulated Janus kinase 2-STAT signaling through a PPARgamma-independent, reactive oxygen species-dependent mechanism. These data provide a novel molecular mechanism of iNOS inhibition by 15dPGJ(2) and confirm its physiological role in anti-inflammation.
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Affiliation(s)
- Ching-Wen Chen
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
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40
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Huang WC, Chen JJ, Inoue H, Chen CC. Tyrosine phosphorylation of I-kappa B kinase alpha/beta by protein kinase C-dependent c-Src activation is involved in TNF-alpha-induced cyclooxygenase-2 expression. J Immunol 2003; 170:4767-75. [PMID: 12707358 DOI: 10.4049/jimmunol.170.9.4767] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The signaling pathway involved in TNF-alpha-induced cyclooxygenase-2 (COX-2) expression was further studied in human NCI-H292 epithelial cells. A protein kinase C (PKC) inhibitor (staurosporine), tyrosine kinase inhibitors (genistein and herbimycin A), or a Src kinase inhibitor (PP2) attenuated TNF-alpha- or 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced COX-2 promoter activity. TNF-alpha- or TPA-induced I-kappaB kinase (IKK) activation was also blocked by these inhibitors, which reversed I-kappaBalpha degradation. Activation of c-Src and Lyn kinases, two Src family members, was inhibited by the PKC, tyrosine kinase, or Src kinase inhibitors. The dominant-negative c-Src (KM) mutant inhibited induction of COX-2 promoter activity by TNF-alpha or TPA. Overexpression of the constitutively active PKCalpha (PKCalpha A/E) or wild-type c-Src plasmids induced COX-2 promoter activity, and these effects were inhibited by the dominant-negative c-Src (KM), NF-kappaB-inducing kinase (NIK) (KA), or IKKbeta (KM) mutant. The dominant-negative PKCalpha (K/R) or c-Src (KM) mutant failed to block induction of COX-2 promoter activity caused by wild-type NIK overexpression. In coimmunoprecipitation experiments, IKKalpha/beta was found to be associated with c-Src and to be phosphorylated on its tyrosine residues after TNF-alpha or TPA treatment. Two tyrosine residues, Tyr(188) and Tyr(199), near the activation loop of IKKbeta, were identified to be crucial for NF-kappaB activation. Substitution of these residues with phenylalanines attenuated COX-2 promoter activity and c-Src-dependent phosphorylation of IKKbeta induced by TNF-alpha or TPA. These data suggest that, in addition to activating NIK, TNF-alpha also activates PKC-dependent c-Src. These two pathways cross-link between c-Src and NIK and converge at IKKalpha/beta, and go on to activate NF-kappaB, via serine phosphorylation and degradation of IkappaB-alpha, and, finally, to initiate COX-2 expression.
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Affiliation(s)
- Wei-Chien Huang
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
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Ali A, Hashem M, Rosman HS, Kazmouz G, Gardin JM, Schrieber TL. Use of platelet glycoprotein IIb/IIIa inhibitors and spontaneous pulmonary hemorrhage. J Invasive Cardiol 2003; 15:186-8. [PMID: 12668843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
BACKGROUND The use of platelet glycoprotein (GP) IIb/IIIa inhibitors in patients undergoing percutaneous coronary intervention has resulted in an impressive reduction in adverse events. Pulmonary hemorrhage is a rare but potentially lethal complication of antithrombotic and antiplatelet therapy. We analyzed the incidence of spontaneous pulmonary hemorrhage following the use of platelet GP IIb/IIIa inhibitors. METHODS The medical records of 1,020 consecutive patients who received GP IIb/IIIa inhibitors and underwent PCI at our institution between August 1997 and December 1999 were reviewed. RESULTS Diffuse pulmonary hemorrhage developed in 7 patients (0.68%), two of whom died. Five of 7 patients with pulmonary hemorrhage had activated clotting times > 250 seconds during the procedure. Activated partial thromboplastin time measured at the time of pulmonary hemorrhage was elevated in all patients (mean, 85 seconds; range, 69 95 seconds). All patients had history of congestive heart failure and had elevated pulmonary capillary wedge pressure and/or left ventricular end-diastolic pressure at the time of the index procedure. Six patients also had evidence of baseline radiographic abnormalities. CONCLUSION Diffuse pulmonary hemorrhage is a potentially disastrous complication of GP Ilb/Illa antagonists. No specific predictors can be identified, but evidence of pulmonary congestion, baseline pulmonary abnormalities and use of higher heparin dosages may predispose patients to this serious complication.
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Affiliation(s)
- Arshad Ali
- Division of ardiology, St Johns Hospital & Medical Center, Detroit, MI, USA.
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42
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Dasgupta S, Zhou Y, Jana M, Banik NL, Pahan K. Sodium phenylacetate inhibits adoptive transfer of experimental allergic encephalomyelitis in SJL/J mice at multiple steps. J Immunol 2003; 170:3874-82. [PMID: 12646656 DOI: 10.4049/jimmunol.170.7.3874] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Experimental allergic encephalomyelitis (EAE) is the animal model for multiple sclerosis. The present study underlines the importance of sodium phenylacetate (NaPA), a drug approved for urea cycle disorders, in inhibiting the disease process of adoptively transferred EAE in female SJL/J mice at multiple steps. Myelin basic protein (MBP)-primed T cells alone induced the expression of NO synthase (iNOS) and the activation of NF-kappaB in mouse microglial cells through cell-cell contact. However, pretreatment of MBP-primed T cells with NaPA markedly inhibited its ability to induce microglial expression of iNOS and activation of NF-kappaB. Consistently, adoptive transfer of MBP-primed T cells, but not that of NaPA-pretreated MBP-primed T cells, induced the clinical symptoms of EAE in female SJL/J mice. Furthermore, MBP-primed T cells isolated from NaPA-treated donor mice were also less efficient than MBP-primed T cells isolated from normal donor mice in inducing iNOS in microglial cells and transferring EAE to recipient mice. Interestingly, clinical symptoms of EAE were much less in mice receiving NaPA through drinking water than those without NaPA. Similar to NaPA, sodium phenylbutyrate, a chemically synthesized precursor of NaPA, also inhibited the disease process of EAE. Histological and immunocytochemical analysis showed that NaPA inhibited EAE-induced spinal cord mononuclear cell invasion and normalized iNOS, nitrotyrosine, and p65 (the RelA subunit of NF-kappaB) expression within the spinal cord. Taken together, our results raise the possibility that NaPA or sodium phenylbutyrate taken through drinking water or milk may reduce the observed neuroinflammation and disease process in multiple sclerosis patients.
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MESH Headings
- Acute Disease
- Administration, Oral
- Adoptive Transfer/methods
- Animals
- Anti-Inflammatory Agents, Non-Steroidal/administration & dosage
- Anti-Inflammatory Agents, Non-Steroidal/pharmacology
- Cell Differentiation/drug effects
- Cell Differentiation/immunology
- Cell Line
- Cell Movement/drug effects
- Cell Movement/immunology
- Chronic Disease
- Disease Progression
- Encephalomyelitis, Autoimmune, Experimental/enzymology
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Encephalomyelitis, Autoimmune, Experimental/prevention & control
- Enzyme Inhibitors/administration & dosage
- Enzyme Inhibitors/pharmacology
- Female
- Growth Inhibitors/administration & dosage
- Growth Inhibitors/pharmacology
- Immunosuppressive Agents/administration & dosage
- Immunosuppressive Agents/pharmacology
- Injections, Intraperitoneal
- Lymphocyte Activation/drug effects
- Mice
- Mice, Inbred Strains
- Microglia/drug effects
- Microglia/enzymology
- Microglia/immunology
- Myelin Basic Protein/antagonists & inhibitors
- Myelin Basic Protein/immunology
- NF-kappa B/antagonists & inhibitors
- NF-kappa B/biosynthesis
- NF-kappa B/metabolism
- Nitric Oxide Synthase/antagonists & inhibitors
- Nitric Oxide Synthase/biosynthesis
- Nitric Oxide Synthase Type II
- Phenylacetates/administration & dosage
- Phenylacetates/pharmacology
- Phenylbutyrates/administration & dosage
- Phenylbutyrates/pharmacology
- Severity of Illness Index
- Spinal Cord/drug effects
- Spinal Cord/immunology
- Spinal Cord/metabolism
- Spinal Cord/pathology
- T-Lymphocyte Subsets/drug effects
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/transplantation
- Transcription Factor RelA
- Tyrosine/analogs & derivatives
- Tyrosine/antagonists & inhibitors
- Tyrosine/biosynthesis
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Affiliation(s)
- Subhajit Dasgupta
- Department of Oral Biology, University of Nebraska Medical Center, Lincoln, NE 68583-0740, USA
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43
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Fernandez LA, Torrealba J, Yagci G, Ishido N, Tsuchida M, Tae Kim H, Dong Y, Oberley T, Fechner J, Colburn MJ, Schultz J, Kanmaz T, Hu H, Knechtle SJ, Hamawy MM. Piceatannol in combination with low doses of cyclosporine A prolongs kidney allograft survival in a stringent rat transplantation model. Transplantation 2002; 74:1609-17. [PMID: 12490796 DOI: 10.1097/00007890-200212150-00020] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The discovery of new immunosuppressive agents has enhanced short-term graft survival. However, current immunosuppressants often induce toxicities that limit their clinical use. Thus, there is a need for new immunosuppressants for use in clinical transplantation. Piceatannol blocks Syk and ZAP-70, tyrosine kinases involved in immune cell activation. We examined whether piceatannol prolongs kidney allograft survival in the stringent ACI-to-Lewis rat model. METHODS Kidney recipients were divided into four groups. Group 1 (n=8) received piceatannol 30 mg/kg per day intravenously and cyclosporine A (CsA) 2 mg/kg per day intramuscularly from day -3 to day 7 after transplantation. At day 8, piceatannol was reduced to 10 mg/kg per day and the combined treatment continued until day 60. Group 2 (n=9) received 2 mg/kg per day CsA alone from day -3 to day 60. Group 3 (n=4) received piceatannol alone as in group 1. Group 4 (n=2) received only the vehicle dimethyl sulfoxide from day -3 to day 60. Graft rejection was defined as either a serum creatinine level more than 2 mg/dL or animal death. RESULTS Group 1 animals survived for at least 115 days (n=8, P<0.05), with several animals maintaining their grafts for more than 200 days. In contrast, 8 of 9 animals in group 2 rejected their grafts within 10 days of transplantation; one animal survived for 71 days. Excellent graft function was maintained in group 1 animals despite withdrawal of immunosuppression. CONCLUSIONS These results are the first to show that piceatannol, when combined with subtherapeutic dosages of CsA, prevents graft rejection, suggesting that targeting Syk and Zap could be useful for preventing graft rejection.
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Affiliation(s)
- Luis A Fernandez
- Department of Surgery, Division of Transplantation, Laboratory of Transplant Immunology, University of Wisconsin-Madison, WI, USA
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Balakrishnan A, Jain-Vakkalagadda B, Yang C, Pal D, Mitra AK. Carrier mediated uptake of L-tyrosine and its competitive inhibition by model tyrosine linked compounds in a rabbit corneal cell line (SIRC)--strategy for the design of transporter/receptor targeted prodrugs. Int J Pharm 2002; 247:115-25. [PMID: 12429490 DOI: 10.1016/s0378-5173(02)00405-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The objective of this study was to investigate the presence of amino acid transporters on the corneal epithelium and to enhance corneal drug absorption through prodrug modification targeted to the amino acid transporters. SIRC was used as a model cell line representing the corneal epithelium. Uptake studies were carried out using [3H] L-tyrosine at 37 degrees C. Temperature, energy and pH dependence studies were carried out. The uptake seems to be composed of a major saturable and minor non-saturable component (V(max) =2.9+/-0.62 nmoles/min/mg protein, K(m) =71+/-21 microM, K(d) =2.6+/-0.6 nl/min/mg protein). No significant inhibition of uptake was observed in the presence of metabolic inhibitors or in the absence of sodium. Competitive inhibition studies were performed in the presence of various amino acids and model tyrosine conjugates (p-nitro and p-chloro benzyl ether conjugate of L-tyrosine). Uptake was inhibited by neutral aromatic and large neutral aliphatic amino acids. L-Tyrosine uptake was inhibited by its ether conjugates in a concentration dependent manner suggesting that these compounds may be sharing the same transport mechanism. This study provides biochemical evidence of the presence of a large neutral amino acid transport system on the corneal epithelium, which may be utilized to enhance the corneal drug transport.
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Affiliation(s)
- Anand Balakrishnan
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 5005 Rockhill Road, Kansas City, MO 64110-2499, USA
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Yasuda K, Nagafuku M, Shima T, Okada M, Yagi T, Yamada T, Minaki Y, Kato A, Tani-Ichi S, Hamaoka T, Kosugi A. Cutting edge: Fyn is essential for tyrosine phosphorylation of Csk-binding protein/phosphoprotein associated with glycolipid-enriched microdomains in lipid rafts in resting T cells. J Immunol 2002; 169:2813-7. [PMID: 12218089 DOI: 10.4049/jimmunol.169.6.2813] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In resting T cells, Csk is constitutively localized in lipid rafts by virtue of interaction with a phosphorylated adaptor protein, Csk-binding protein (Cbp)/phosphoprotein associated with glycolipid-enriched microdomains, and sets an activation threshold in TCR signaling. In this study, we examined a kinase responsible for Cbp phosphorylation in T cell membrane rafts. By analyzing T cells from Fyn-/- mice, we clearly demonstrated that Fyn, but not Lck, has its kinase activity in membrane rafts, and plays a critical role in Cbp phosphorylation, Cbp-Csk interaction, and Csk kinase activity. Naive CD44(low)CD62 ligand(high) T cells were substantially reduced in Fyn-/- mice, presumably due to the inhibition of Cbp phosphorylation. Thus, Fyn mediates Cbp-Csk interaction and recruits Csk to rafts by phosphorylating Cbp. Csk recruited to rafts would then be activated and inhibit the kinase activity of Lck to keep resting T cells in a quiescent state. Our results elucidate a negative regulatory role for Fyn in proximal TCR signaling in lipid rafts.
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Affiliation(s)
- Koubun Yasuda
- Department of Oncogenesis, Graduate School of Medicine, Osaka University, Osaka, Japan
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Dauvillier S, Mérida P, Visintin M, Cattaneo A, Bonnerot C, Dariavach P. Intracellular single-chain variable fragments directed to the Src homology 2 domains of Syk partially inhibit Fc epsilon RI signaling in the RBL-2H3 cell line. J Immunol 2002; 169:2274-83. [PMID: 12193692 DOI: 10.4049/jimmunol.169.5.2274] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Intracellular expression of Ab fragments has been efficiently used to inactivate therapeutic targets, oncogene products, and to induce viral resistance in plants. Ab fragments expressed in the appropriate cell compartment may also help to elucidate the functions of a protein of interest. We report in this study the successful targeting of the protein tyrosine kinase Syk in the RBL-2H3 rat basophilic leukemia cell line. We isolated from a phage display library human single-chain variable fragments (scFv) directed against the portion of Syk containing the Src homology 2 domains and the linker region that separates them. Among them, two scFv named G4G11 and G4E4 exhibited the best binding to Syk in vivo in a yeast two-hybrid selection system. Stable transfectants of RBL-2H3 cells expressing cytosolic G4G11 and G4E4 were established. Immunoprecipitation experiments showed that intracellular G4G11 and G4E4 bind to Syk, but do not inhibit the activation of Syk following FcepsilonRI aggregation, suggesting that the scFv do not affect the recruitment of Syk to the receptor. Nevertheless, FcepsilonRI-mediated calcium mobilization and the release of inflammatory mediators are inhibited, and are consistent with a defect in Bruton's tyrosine kinase and phospholipase C-gamma2 tyrosine phosphorylation and activation. Interestingly, FcepsilonRI-induced mitogen-activated protein kinase phosphorylation is not altered, suggesting that intracellular G4G11 and G4E4 do not prevent the coupling of Syk to the Ras pathway, but they selectively inhibit the pathway involving phospholipase C-gamma2 activation.
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Affiliation(s)
- Stéphanie Dauvillier
- Institut de Génétique Moléculaire de Montpellier, Unité Mixte de Recherche 5535 Centre National de la Recherche Scientifique, Montpellier, France
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Fusa K, Saigusa T, Koshikawa N, Cools AR. Tyrosine-induced release of dopamine is under inhibitory control of presynaptic dopamine D2 and, probably, D3 receptors in the dorsal striatum, but not in the nucleus accumbens. Eur J Pharmacol 2002; 448:143-50. [PMID: 12144934 DOI: 10.1016/s0014-2999(02)01911-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Stimulation of dopamine D2-like receptors decreases extracellular dopamine in the dorsal striatum and the nucleus accumbens. It is unknown whether the role of these receptors differs from that of dopamine D3 receptors. It is also unknown to what extent the role of these two types of receptors varies across both structures. Using microdialysis, we therefore investigated whether intracerebrally administered quinpirole, a dopamine D2-like receptor agonist, and PD 128907, (S(+)-(4aR,10bR)-3,4,4a,10b-tetrahydro-4-propyl-2H,5H-[1]-benzopyrano[4,3-b]-1,4-oxazin-9-ol, a dopamine D3 receptor preferring agonist, differentially alter the tyrosine-induced increase of extracellular dopamine in the dorsal striatum and the nucleus accumbens, respectively. Perfusion of tyrosine (100 microM) into the dorsal striatum and the nucleus accumbens enhanced extracellular dopamine in a physiological manner in both areas. Infusion of the Na(+) channel blocker tetrodotoxin (2 microM) suppressed the enhanced level of dopamine derived from exogenous tyrosine in both brain areas. Infusion of the dopamine D2-like receptor agonist quinpirole at a concentration (1 nM), which alone did not affect basal extracellular dopamine, reduced tyrosine-enhanced extracellular dopamine when infused into the dorsal striatum, but not into the nucleus accumbens; the preferential dopamine D3 receptor agonist, PD 128907, had similar effects. Haloperidol, a dopamine D2-like receptor antagonist, given systemically at a dose, which alone did not significantly affect basal dopamine levels (10 nmol/kg i.p.), enhanced extracellular dopamine derived from exogenous tyrosine. This haloperidol treatment antagonized only the quinpirole-induced, but not the PD 128907-induced reduction in dopamine levels seen in tyrosine-treated rats. The results show that extracellular dopamine derived from exogenous tyrosine is under inhibitory control of presynaptic dopamine D2-like receptors in the dorsal striatum, but not in the nucleus accumbens; to what extent the same holds for dopamine D3 receptors remains to be proven. Future studies are required to elucidate whether the noted difference is absolute or not.
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Affiliation(s)
- Koichi Fusa
- Department of Dental Anaesthesiology, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan
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48
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Shiojiri T, Wada K, Nakajima A, Katayama K, Shibuya A, Kudo C, Kadowaki T, Mayumi T, Yura Y, Kamisaki Y. PPAR gamma ligands inhibit nitrotyrosine formation and inflammatory mediator expressions in adjuvant-induced rheumatoid arthritis mice. Eur J Pharmacol 2002; 448:231-8. [PMID: 12144946 DOI: 10.1016/s0014-2999(02)01946-5] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Peroxisome proliferator-activated receptor gamma (PPARgamma) is a nuclear receptor, whose activation has been linked to several physiologic pathways including those related to the regulation of insulin sensitivity. Here, we investigate effects of PPARgamma specific ligands, rosiglitazone and pioglitazone, on formation of nitrotyrosine and increased expression of inflammatory mediators such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 and intercellular adhesion molecule-1 (ICAM-1) in adjuvant-induced murine arthritis. Administration of rosiglitazone or pioglitazone (30 mg/kg, p.o.) significantly inhibited the adjuvant-induced increase in formation of nitrotyrosine and expression of iNOS on both ankle and temporomandibular joints. Rosiglitazone also inhibited the adjuvant-induced expression of M30 positive cells, as a marker of apoptosis, in the joint tissues. In addition, treatment with rosiglitazone or pioglitazone (30 microM) inhibited lipopolysaccharide plus tumor necrosis factor (TNF)-alpha-induced protein expression of iNOS, cyclooxygenase-2, ICAM-1 and nitrotyrosine formation in RAW 264 cells, a murine macrophage-like cell line. Rosiglitazone or pioglitazone inhibited increase in phosphorylated I-kappaB (pI-kappaB) expression, as an index of activation of nuclear factor (NF)-kappaB, in both joint tissues and RAW264 cells. Furthermore, in PPARgamma-transfected HEK293 cells, rosiglitazone inhibited the TNF-alpha-stimulated response using NF-kappaB-mediated transcription reporter assay. These results indicate that PPARgamma ligands may possess anti-inflammatory activity against adjuvant-induced arthritis via the inhibition of NF-kappaB pathway.
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Affiliation(s)
- Tomoko Shiojiri
- Department of Pharmacology, Graduate School of Dentistry, Osaka University, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan
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49
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Harding S, Lipp P, Alexander DR. A therapeutic CD4 monoclonal antibody inhibits TCR-zeta chain phosphorylation, zeta-associated protein of 70-kDa Tyr319 phosphorylation, and TCR internalization in primary human T cells. J Immunol 2002; 169:230-8. [PMID: 12077249 DOI: 10.4049/jimmunol.169.1.230] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The molecular mechanisms mediating the inhibitory effects of a humanized CD4 mAb YHB.46 on primary human CD4(+) T cells were investigated. Preincubation of T cells with soluble YHB.46 caused a general inhibition of TCR-stimulated protein tyrosine phosphorylation events, including a reduction in phosphorylation of p95(vav), linker for activation of T cells, and Src homology 2 domain-containing leukocyte protein of 76-kDa signaling molecules. A marked reduction in activation of the Ras/mitogen-activated protein kinase pathway was also observed. Examination of the earliest initiation events of TCR signal transduction showed that YHB.46 inhibited TCR-zeta chain phosphorylation together with recruitment and tyrosine phosphorylation of the zeta-associated protein of 70-kDa tyrosine kinase, particularly at Tyr(319), as well as reduced recruitment of p56(lck) to the TCR-zeta and zeta-associated protein of 70-kDa complex. These inhibitory events were associated with inhibition of TCR endocytosis. Our results show that the YHB.46 mAb is a powerful inhibitor of the early initiating events of TCR signal transduction.
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Affiliation(s)
- Susanne Harding
- Laboratories of Lymphocyte Signaling and Development, The Babraham Institute, Cambridge, United Kingdom
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Samoszu M, Brennan ML, To V, Leonor L, Zheng L, Fu X, Hazen SL. Association between nitrotyrosine levels and microvascular density in human breast cancer. Breast Cancer Res Treat 2002; 74:271-8. [PMID: 12206516 DOI: 10.1023/a:1016328526866] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Nitrotyrosine (NO2Y) is a global marker of protein modification by reactive nitrogen species such as peroxynitrite derived from nitric oxide (NO). Because NO and its derivatives are postulated to enhance carcinogenesis, we used stable isotope dilution mass spectrometry to measure the levels of NO2Y in 30 samples of human breast cancer of varying pathologic types. In the samples tested, the NO2Y levels were generally low (average of 14.1 +/- 9.2 micromol NO2Y per mole of tyrosine). Breast cancers with a high microvascular density, however, had a significantly higher average level of NO2Y than tumors with a low microvascular density (20 v.s. 10 micromol NO2Y per mole of tyrosine, p = 0.007 by two-tailed t-test, assuming unequal variances of two samples). There was no apparent association between NO2Y levels and the differentiation of the tumors, tumor aneuploidy, estrogen receptor status, HER-2 expression, lymph node status, or infiltration of the tumors by neutrophils or eosinophils. When the tissues were stained by immunohistochemistry for NO2Y, the NO2Y was localized predominantly within inflammatory cells located immediately adjacent to blood vessels at the edges of the tumors. NO2Y was generally not evident within the tumor cells or inflammatory cells in the stroma. We conclude that low levels of reactive nitrogen species are located predominantly within inflammatory cells near blood vessels of breast cancer and that higher NO2Y levels are associated with an increased density of blood vessels. Our findings, therefore, support a possible association between inflammatory cells and reactive nitrogen species in modulating microvascular density at the edges of breast cancer.
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Affiliation(s)
- Michael Samoszu
- Pathology Department, University of California, Irvine, USA.
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