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Wang Z, Zhan C, Zeng F, Wu S. A biopolymer-based and inflammation-responsive nanodrug for rheumatoid arthritis treatment via inhibiting JAK-STAT and JNK signalling pathways. NANOSCALE 2020; 12:23013-23027. [PMID: 33191426 DOI: 10.1039/d0nr05551d] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Rheumatoid arthritis (RA) is a common chronic autoimmune disease associated with progressive disability, systemic complications, and poor prognosis. The improved understanding of the roles of immune signaling pathway inhibitors has shed light on designing new and more effective approaches for RA treatment. In this work, an inflammation-responsive and molecularly targeted drug system has been developed for RA therapy. The drug carrier was synthesized by covalently grafting hydrophobic cholesterol (Chol) molecules onto a hydrophilic chondroitin sulfate (CS) chain via the inflammation-responsive diselenide bonds (SeSe). The resultant amphiphilic polymer CSSeSeChol readily forms nanoparticles (NPs) and encapsulates two kinase inhibitors tofacitinib and SP600125 in aqueous media. Upon administration into the RA mouse model, the nanodrug accumulates in RA lesions and releases the inhibitors for regulating the JAK-STAT and JNK pathways. As a result, the nanodrug exhibits satisfactory efficacy in RA treatment by suppressing the expression of relevant pro-inflammatory cytokines, blocking the activation of osteoclasts and providing protection for cartilage and joints.
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Affiliation(s)
- Ziqian Wang
- Biomedical Division, State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, College of Materials Science and Engineering, South China University of Technology, Wushan Road 381, Guangzhou 510640, China.
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2
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Barzago MM, Kurosaki M, Fratelli M, Bolis M, Giudice C, Nordio L, Cerri E, Domenici L, Terao M, Garattini E. Generation of a new mouse model of glaucoma characterized by reduced expression of the AP-2β and AP-2δ proteins. Sci Rep 2017; 7:11140. [PMID: 28894266 PMCID: PMC5593953 DOI: 10.1038/s41598-017-11752-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 08/30/2017] [Indexed: 12/20/2022] Open
Abstract
We generated 6 transgenic lines with insertion of an expression plasmid for the R883/M xanthine dehydrogenase (XDH) mutant protein. Approximately 20% of the animals deriving from one of the transgenic lines show ocular abnormalities and an increase in intra-ocular pressure which are consistent with glaucoma. The observed pathologic phenotype is not due to expression of the transgene, but rather the consequence of the transgene insertion site, which has been defined by genome sequencing. The insertion site maps to chromosome 1qA3 in close proximity to the loci encoding AP-2β and AP-2δ, two proteins expressed in the eye. The insertion leads to a reduction in AP-2β and AP-2δ levels. Down-regulation of AP-2β expression is likely to be responsible for the pathologic phenotype, as conditional deletion of the Tfap2b gene in the neural crest has recently been shown to cause defective development of the eye anterior segment and early-onset glaucoma. In these conditional knock-out and our transgenic mice, the morphological/histological features of the glaucomatous pathology are surprisingly similar. Our transgenic mouse represents a model of angle-closure glaucoma and a useful tool for the study of the pathogenesis and the development of innovative therapeutic strategies.
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Affiliation(s)
- Maria Monica Barzago
- Laboratory of Molecular Biology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", via La Masa 19, 20156, Milano, Italy
| | - Mami Kurosaki
- Laboratory of Molecular Biology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", via La Masa 19, 20156, Milano, Italy
| | - Maddalena Fratelli
- Laboratory of Molecular Biology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", via La Masa 19, 20156, Milano, Italy
| | - Marco Bolis
- Laboratory of Molecular Biology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", via La Masa 19, 20156, Milano, Italy
| | - Chiara Giudice
- DIVET, Faculty of Veterinary Medicine, University of Milan, Italy, Via Celoria 10, 20113, Milano, Italy
| | - Laura Nordio
- DIVET, Faculty of Veterinary Medicine, University of Milan, Italy, Via Celoria 10, 20113, Milano, Italy
| | - Elisa Cerri
- Consiglio Nazionale delle Ricerche (CNR), Neuroscience Institute, Pisa, Italy
| | - Luciano Domenici
- Consiglio Nazionale delle Ricerche (CNR), Neuroscience Institute, Pisa, Italy
- Department of Applied Clinical Sciences and Biotechnology (DISCAB), University of L'Aquila, L'Aquila, Italy
| | - Mineko Terao
- Laboratory of Molecular Biology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", via La Masa 19, 20156, Milano, Italy.
| | - Enrico Garattini
- Laboratory of Molecular Biology, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", via La Masa 19, 20156, Milano, Italy.
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Structure and function of mammalian aldehyde oxidases. Arch Toxicol 2016; 90:753-80. [DOI: 10.1007/s00204-016-1683-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 02/16/2016] [Indexed: 12/12/2022]
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Granger DN, Kvietys PR. Reperfusion injury and reactive oxygen species: The evolution of a concept. Redox Biol 2015; 6:524-551. [PMID: 26484802 PMCID: PMC4625011 DOI: 10.1016/j.redox.2015.08.020] [Citation(s) in RCA: 931] [Impact Index Per Article: 103.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 08/31/2015] [Indexed: 12/11/2022] Open
Abstract
Reperfusion injury, the paradoxical tissue response that is manifested by blood flow-deprived and oxygen-starved organs following the restoration of blood flow and tissue oxygenation, has been a focus of basic and clinical research for over 4-decades. While a variety of molecular mechanisms have been proposed to explain this phenomenon, excess production of reactive oxygen species (ROS) continues to receive much attention as a critical factor in the genesis of reperfusion injury. As a consequence, considerable effort has been devoted to identifying the dominant cellular and enzymatic sources of excess ROS production following ischemia-reperfusion (I/R). Of the potential ROS sources described to date, xanthine oxidase, NADPH oxidase (Nox), mitochondria, and uncoupled nitric oxide synthase have gained a status as the most likely contributors to reperfusion-induced oxidative stress and represent priority targets for therapeutic intervention against reperfusion-induced organ dysfunction and tissue damage. Although all four enzymatic sources are present in most tissues and are likely to play some role in reperfusion injury, priority and emphasis has been given to specific ROS sources that are enriched in certain tissues, such as xanthine oxidase in the gastrointestinal tract and mitochondria in the metabolically active heart and brain. The possibility that multiple ROS sources contribute to reperfusion injury in most tissues is supported by evidence demonstrating that redox-signaling enables ROS produced by one enzymatic source (e.g., Nox) to activate and enhance ROS production by a second source (e.g., mitochondria). This review provides a synopsis of the evidence implicating ROS in reperfusion injury, the clinical implications of this phenomenon, and summarizes current understanding of the four most frequently invoked enzymatic sources of ROS production in post-ischemic tissue. Reperfusion injury is implicated in a variety of human diseases and disorders. Evidence implicating ROS in reperfusion injury continues to grow. Several enzymes are candidate sources of ROS in post-ischemic tissue. Inter-enzymatic ROS-dependent signaling enhances the oxidative stress caused by I/R. .
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Affiliation(s)
- D Neil Granger
- Department of Molecular & Cellular Physiology, Louisiana State University Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932, United States.
| | - Peter R Kvietys
- Department of Physiological Sciences, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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Agarwal A, Banerjee A, Banerjee UC. Xanthine oxidoreductase: a journey from purine metabolism to cardiovascular excitation-contraction coupling. Crit Rev Biotechnol 2011; 31:264-80. [PMID: 21774633 DOI: 10.3109/07388551.2010.527823] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Xanthine oxidoreductase (XOR) is a ubiquitous complex cytosolic molybdoflavoprotein which controls the rate limiting step of purine catabolism by converting xanthine to uric acid. It is known that optimum concentrations of uric acid (UA) and reactive oxygen species (ROS) are necessary for normal functioning of the body. The ability of XOR to perform detoxification reactions, and to synthesize UA and reactive oxygen species (ROS) makes it a versatile intra- and extra-cellular protective "housekeeping enzyme". It is also an important component of the innate immune system. The enzyme is a target of drugs against gout and hyperuricemia and the protein is of major interest as it is associated with ischemia reperfusion (I/R) injury, vascular disorders in diabetes, cardiovascular disorders, adipogenesis, metabolic syndrome, cancer, and many other disease conditions. Xanthine oxidoreductase in conjugation with antibodies has been shown to have an anti-tumor effect due to its ability to produce ROS, which in turn reduces the growth of cancer tissues. Apart from this, XOR in association with nitric oxide synthase also participates in myocardial excitation-contraction coupling. Although XOR was discovered over 100 years ago, its physiological and pathophysiological roles are still not clearly elucidated. In this review, various physiological and pathophysiological functional aspects of XOR and its association with various forms of cancer are discussed in detail.
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Affiliation(s)
- Amit Agarwal
- Department of Pharmaceutical Technology (Biotechnology), National Institute of Pharmaceutical Education and Research, Punjab, India
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Forman JP, Choi H, Curhan GC. Fructose and vitamin C intake do not influence risk for developing hypertension. J Am Soc Nephrol 2009; 20:863-71. [PMID: 19144761 DOI: 10.1681/asn.2008050473] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Higher uric acid levels are associated with an increased risk for developing hypertension. Higher intake of fructose increases plasma uric acid levels and higher intake of vitamin C reduces uric acid levels, but whether these nutrients are independently associated with the risk for developing hypertension is unknown. We studied this question by analyzing data from participants of three large and independent prospective cohorts: Nurses' Health Study 1 (n = 88,540), Nurses' Health Study 2 (n = 97,315), and the Health Professionals Follow-up Study (n = 37,375). Relative risks and 95% confidence intervals for incident hypertension were computed according to quintiles of fructose intake and categories of vitamin C intake using multivariable Cox proportional hazards regression. Fructose intake was not associated with the risk for developing hypertension; the multivariable relative risks (95% confidence intervals) for the highest compared with the lowest quintile of fructose intake were 1.02 (0.99 to 1.06) in Nurses' Health Study 1, 1.03 (0.98 to 1.08) in Nurses' Health Study 2, and 0.99 (0.93 to 1.05) in Heath Professionals Follow-up Study. Regarding vitamin C, the relative risks for individuals who consumed > or =1500 mg/d compared with those who consumed <250 mg/d were 0.89 (0.83 to 0.96) in Nurses' Health Study 1, 1.02 (0.91 to 1.14) in Nurses' Health Study 2, and 1.06 (0.97 to 1.15) in Health Professionals Follow-up Study. In conclusion, fructose and vitamin C intake do not substantially influence the risk for developing hypertension.
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Affiliation(s)
- John P Forman
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital, 3rd Floor, 181 Longwood Avenue, Boston, Massachusetts 02115, USA.
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Lin J, Xu P, LaVallee P, Hoidal JR. Identification of proteins binding to E-Box/Ku86 sites and function of the tumor suppressor SAFB1 in transcriptional regulation of the human xanthine oxidoreductase gene. J Biol Chem 2008; 283:29681-9. [PMID: 18772145 PMCID: PMC2573066 DOI: 10.1074/jbc.m802076200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Revised: 08/01/2008] [Indexed: 01/24/2023] Open
Abstract
The xanthine oxidoreductase gene (XOR) encodes an important source of reactive oxygen species and uric acid, and its expression is associated with various human diseases including several forms of cancer. We previously reported that basal human XOR (hXOR) expression is restricted or repressed by E-box and TATA-like elements and a cluster of transcriptional proteins, including AREB6-like proteins and DNA-dependent protein kinase (DNA-PK). We now demonstrate that the cluster contains the tumor suppressors SAFB1, BRG1, and SAF-A. We further demonstrate that SAFB1 silencing increases hXOR expression and that SAFB1 directly binds to the E-box. Multiple studies in vitro and in vivo including pulldown, immunoprecipitation and chromatin immunoprecipitation analyses indicate that SAFB1, Ku86, and BRG1 associate with each other. The results suggest that the SAFB1 complex binds to the hXOR promoter in a chromatin environment and plays a critical role in restricting hXOR expression via its direct interaction with the E-box, DNA-PK, and tumor suppressors. Moreover, we demonstrate that the cytokine, oncostatin M (OSM), induces the phosphorylation of SAFB1 and that the OSM-induced hXOR mRNA expression is significantly inhibited by silencing the DNA-PK catalytic subunit or SAFB1 expression. The present studies for the first time demonstrate that hXOR is a tumor suppressor-targeted gene and that the phosphorylation of SAFB1 is regulated by OSM, providing a molecular basis for understanding the role of SAFB1-regulated hXOR transcription in cytokine stimulation and tumorigenesis.
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Affiliation(s)
- Junji Lin
- Department of Internal Medicine, Division of Respiratory, Critical Care, and Occupational Medicine, University of Utah Health Sciences Center and Veterans Affairs Medical Center, Salt Lake City, Utah 84132, USA
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Snelgrove RJ, Edwards L, Rae AJ, Hussell T. An absence of reactive oxygen species improves the resolution of lung influenza infection. Eur J Immunol 2006; 36:1364-73. [PMID: 16703568 DOI: 10.1002/eji.200635977] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Three influenza virus pandemics occurred in the last century, in 1918 killing 40-50 million people. In the absence of strain-specific vaccines, with potential resistance to antivirals and the threat of an imminent pandemic, strategies that alleviate symptoms are a priority. Reactive oxygen species are potent antimicrobial agents but cause immunopathology when produced in excess. Mice lacking a functional phagocyte NADPH oxidase (Cybb tm1 mice) or treated with the metalloporphyrin antioxidant manganese (III) tetrakis (N-ethyl pyridinium-2-yl) porpyhrin (MnTE-2-PyP) show heightened inflammatory infiltrates in their airways in response to pulmonary influenza infection, with augmented macrophage populations and a Th1-skewed T cell infiltrate. Underlying this exuberant macrophage response was a significant reduction in apoptosis and down-regulation of the myeloid inhibitory molecule CD200. Both, Cybb tm1 and MnTE-2-PyP-treated mice exhibited a reduced influenza titer in the lung parenchyma. Inflammatory infiltrate into the lung parenchyma was markedly reduced and lung function significantly improved. Manipulation of the homeostatic control of myeloid cells by inflammatory mediators therefore represents a novel therapeutic strategy in the treatment of influenza virus infection.
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Affiliation(s)
- Robert J Snelgrove
- Kennedy Institute of Rheumatology, Imperial College London, Hammersmith, UK
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Terao M, Kurosaki M, Barzago MM, Varasano E, Boldetti A, Bastone A, Fratelli M, Garattini E. Avian and Canine Aldehyde Oxidases. J Biol Chem 2006; 281:19748-61. [PMID: 16672219 DOI: 10.1074/jbc.m600850200] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Aldehyde oxidases are molybdo-flavoenzymes structurally related to xanthine oxidoreductase. They catalyze the oxidation of aldehydes or N-heterocycles of physiological, pharmacological, and toxicological relevance. Rodents are characterized by four aldehyde oxidases as follows: AOX1 and aldehyde oxidase homologs 1-3 (AOH1, AOH2, and AOH3). Humans synthesize a single functional aldehyde oxidase, AOX1. Here we define the structure and the characteristics of the aldehyde oxidase genes and proteins in chicken and dog. The avian genome contains two aldehyde oxidase genes, AOX1 and AOH, mapping to chromosome 7. AOX1 and AOH are structurally very similar and code for proteins whose sequence was deduced from the corresponding cDNAs. AOX1 is the ortholog of the same gene in mammals, whereas AOH represents the likely ancestor of rodent AOH1, AOH2, and AOH3. The dog genome is endowed with two structurally conserved and active aldehyde oxidases clustering on chromosome 37. Cloning of the corresponding cDNAs and tissue distribution studies demonstrate that they are the orthologs of rodent AOH2 and AOH3. The vestiges of dog AOX1 and AOH1 are recognizable upstream of AOH2 and AOH3 on the same chromosome. Comparison of the complement and the structure of the aldehyde oxidase and xanthine oxidoreductase genes in vertebrates and other animal species indicates that they evolved through a series of duplication and inactivation events. Purification of the chicken AOX1 protein to homogeneity from kidney demonstrates that the enzyme possesses retinaldehyde oxidase activity. Unlike humans and most other mammals, dog and chicken are devoid of liver aldehyde oxidase activity.
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Affiliation(s)
- Mineko Terao
- Laboratory of Molecular Biology, Centro Catullo e Daniela Borgomainerio, Istituto di Ricerche Farmacologiche Mario Negri, via Eritrea 62, 20157 Milano, Italy
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Xu P, LaVallee PA, Lin JJ, Hoidal JR. Characterization of Proteins Binding to E-box/Ku86 Sites and Function of Ku86 in Transcriptional Regulation of the Human Xanthine Oxidoreductase Gene. J Biol Chem 2004; 279:16057-63. [PMID: 14761964 DOI: 10.1074/jbc.m305856200] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
We reported previously that E-box and TATA-like elements repress human xanthine oxidoreductase gene (hXOR) expression. In the present investigation, we determined the means by which the E-box site functions in this basal repression. DNA affinity purification demonstrated that at least five proteins are involved in the nuclear protein complex binding to the E-box and adjacent Ku86-binding sites. Amino acid sequence analysis demonstrated that three proteins, DNA-PK catalytic subunit, Ku86, and Ku70 are components of DNA-dependent protein kinase (DNA-PK). By electrophoretic mobility shift assays, gel-shift, and site-directed mutagenesis, we confirmed Ku86 binding to the Ku86 site. Studies indicated that the other two proteins of the complex are AREB6-like proteins binding to the E-box. Pull-down and immunoprecipitation analyses demonstrated the binding of Ku86 to AREB6-like proteins. The functional loss of Ku86 increases hXOR promoter activity and transcript expression. Based on the findings, we propose that DNA-PK/AREB6-like proteins play a central role in repression of basal hXOR activity. AREB6-like proteins specifically bind to the E-box, whereas Ku86 binds an adjacent site and recruits DNA-PK catalytic subunit and Ku70 proteins. A working model is presented to account for the role of DNA-PK and AREB6-like proteins in regulating hXOR activity.
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Affiliation(s)
- Ping Xu
- Department of Internal Medicine, Division of Respiratory, Critical Care and Occupational Medicine, University of Utah Health Sciences Center and Veterans Affairs Medical Center, Salt Lake City, Utah 84132, USA
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Aklillu E, Carrillo JA, Makonnen E, Bertilsson L, Ingelman-Sundberg M. Xanthine oxidase activity is influenced by environmental factors in Ethiopians. Eur J Clin Pharmacol 2003; 59:533-6. [PMID: 12937875 DOI: 10.1007/s00228-003-0653-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2002] [Accepted: 07/07/2003] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To investigate xanthine oxidase (XO) polymorphism in Ethiopians and influence of environmental factors, smoking habit and gender-related differences on enzyme activity among Ethiopians living in Ethiopia or Sweden. METHODS One hundred healthy unrelated Ethiopians living in Ethiopia and 73 living in Sweden participated in the study. Subjects received a 100-mg oral dose of caffeine before bedtime. All urine voided in the following 8 h was collected and the concentrations of 1-methyluracil (1U) and 1-methylxanthine (1X) micromol/l) were analyzed by means of high-performance liquid chromatography. The 1U/(1X+1U) metabolic ratio (MR) was calculated and used as an index of XO activity. RESULTS XO activity was not normally distributed ( P<0.0001; Shapiro-Wilk's test). The incidence of putative XO poor metabolizers in Ethiopians was 4%. The effect of differences in country of residence, gender and smoking habit was analyzed using three-way ANOVA/MANOVA. The post-hoc test ( P<0.05) and Kruskal-Wallis ANOVA ( P<0.004), median test showed a significant difference in XO activity among Ethiopians living in Ethiopia compared with those living in Sweden, the activity being higher in Ethiopians living in Ethiopia. The 95% CI for differences between the two means was (0.012; 0.044). No significant difference was observed in XO MR between men and women or between smokers and non-smokers, the 95% CI for the differences being (-0.059; 0.037) and (-0.010; 0.016) respectively. CONCLUSION The XO activity is polymorphic in Ethiopians. Neither gender nor smoking-related differences influenced XO activity but the difference in activity between Ethiopians living in Sweden or in Ethiopia indicates influence of other environmental factors such as dietary habits on XO activity.
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Affiliation(s)
- Eleni Aklillu
- Division of Molecular Toxicology, IMM, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
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Wright RM, Ginger LA, Kosila N, Elkins ND, Essary B, McManaman JL, Repine JE. Mononuclear phagocyte xanthine oxidoreductase contributes to cytokine-induced acute lung injury. Am J Respir Cell Mol Biol 2003; 30:479-90. [PMID: 14512376 DOI: 10.1165/rcmb.2003-0309oc] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Acute lung injury (ALI) is characterized by increased alveolar cytokines, inflammatory cell infiltration, oxidative stress, and alveolar cell apoptosis. Previous work suggested that xanthine oxidoreductase (XOR) may contribute to oxidative stress in ALI as a product of the vascular endothelial cell. We present evidence that cytokine induced lung inflammation and injury involves activation of XOR in the newly recruited mononuclear phagocytes (MNP). We found that XOR was increased predominantly in the MNP that increase rapidly in the lungs of rats that develop ALI following intratracheal cytokine insufflation. XOR was recovered from the MNP largely converted to its oxygen radical generating, reversible O-form, and alveolar MNP exhibited increased oxidative stress as evidenced by increased nitrotyrosine staining. Cytokine insufflation also increased alveolar cell apoptosis. A functional role for XOR in cytokine-induced inflammation was demonstrated when feeding rats two different XOR inhibitors, tungsten and allopurinol, decreased MNP XOR induction, nitrotyrosine staining, inflammatory cell infiltration, and alveolar cell apoptosis. Transfer of control or allopurinol treated MNP into rat lungs confirmed a specific role for MNP XOR in promoting lung inflammation. These data indicate that XOR can contribute to lung inflammation by its expression and conversion in a highly mobile inflammatory cell population.
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Affiliation(s)
- Richard M Wright
- Department of Pulmonary Sciences, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
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Garattini E, Mendel R, Romão MJ, Wright R, Terao M. Mammalian molybdo-flavoenzymes, an expanding family of proteins: structure, genetics, regulation, function and pathophysiology. Biochem J 2003; 372:15-32. [PMID: 12578558 PMCID: PMC1223366 DOI: 10.1042/bj20030121] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2003] [Revised: 02/04/2003] [Accepted: 02/10/2003] [Indexed: 12/11/2022]
Abstract
The molybdo-flavoenzymes are structurally related proteins that require a molybdopterin cofactor and FAD for their catalytic activity. In mammals, four enzymes are known: xanthine oxidoreductase, aldehyde oxidase and two recently described mouse proteins known as aldehyde oxidase homologue 1 and aldehyde oxidase homologue 2. The present review article summarizes current knowledge on the structure, enzymology, genetics, regulation and pathophysiology of mammalian molybdo-flavoenzymes. Molybdo-flavoenzymes are structurally complex oxidoreductases with an equally complex mechanism of catalysis. Our knowledge has greatly increased due to the recent crystallization of two xanthine oxidoreductases and the determination of the amino acid sequences of many members of the family. The evolution of molybdo-flavoenzymes can now be traced, given the availability of the structures of the corresponding genes in many organisms. The genes coding for molybdo-flavoenzymes are expressed in a cell-specific fashion and are controlled by endogenous and exogenous stimuli. The recent cloning of the genes involved in the biosynthesis of the molybdenum cofactor has increased our knowledge on the assembly of the apo-forms of molybdo-flavoproteins into the corresponding holo-forms. Xanthine oxidoreductase is the key enzyme in the catabolism of purines, although recent data suggest that the physiological function of this enzyme is more complex than previously assumed. The enzyme has been implicated in such diverse pathological situations as organ ischaemia, inflammation and infection. At present, very little is known about the pathophysiological relevance of aldehyde oxidase, aldehyde oxidase homologue 1 and aldehyde oxidase homologue 2, which do not as yet have an accepted endogenous substrate.
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Affiliation(s)
- Enrico Garattini
- Laboratory of Molecular Biology, Istituto di Ricerche Farmacologiche Mario Negri, via Eritrea 62, 20157 Milan, Italy.
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Martelin E, Lapatto R, Raivio KO. Regulation of xanthine oxidoreductase by intracellular iron. Am J Physiol Cell Physiol 2002; 283:C1722-8. [PMID: 12388055 DOI: 10.1152/ajpcell.00280.2002] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Xanthine oxidoreductase (XOR) may produce reactive oxygen species and play a role in ischemia-reperfusion injury. Because tissue iron levels increase after ischemia, and because XOR contains functionally critical iron-sulfur clusters, we studied the effects of intracellular iron on XOR expression. Ferric ammonium citrate and FeSO(4) elevated intracellular iron levels and increased XOR activity up to twofold in mouse fibroblast and human bronchial epithelial cells. Iron increased XOR protein and mRNA levels, whereas protein and RNA synthesis inhibitors abolished the induction of XOR activity. A human XOR promoter construct (nucleotides +42 to -1937) was not induced by iron in human embryonic kidney cells. Hydroxyl radical scavengers did not block induction of XOR activity by iron. Iron chelation by deferoxamine (DFO) decreased XOR activity but did not lower endogenous XOR protein or mRNA levels. Furthermore, DFO reduced the activity of overexpressed human XOR but not the amount of immunoreactive protein. Our data show that XOR activity is transcriptionally induced by iron but posttranslationally inactivated by iron chelation.
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Affiliation(s)
- Eeva Martelin
- Hospital for Children and Adolescents, Research Laboratory, University of Helsinki, Biomedicum Helsinki, 00014 University of Helsinki, Finland.
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Abstract
Xanthine oxidoreductase (XOR) is a complex molybdoflavoenzyme, present in milk and many other tissues, which has been studied for over 100 years. While it is generally recognized as a key enzyme in purine catabolism, its structural complexity and specialized tissue distribution suggest other functions that have never been fully identified. The publication, just over 20 years ago, of a hypothesis implicating XOR in ischemia-reperfusion injury focused research attention on the enzyme and its ability to generate reactive oxygen species (ROS). Since that time a great deal more information has been obtained concerning the tissue distribution, structure, and enzymology of XOR, particularly the human enzyme. XOR is subject to both pre- and post-translational control by a range of mechanisms in response to hormones, cytokines, and oxygen tension. Of special interest has been the finding that XOR can catalyze the reduction of nitrates and nitrites to nitric oxide (NO), acting as a source of both NO and peroxynitrite. The concept of a widely distributed and highly regulated enzyme capable of generating both ROS and NO is intriguing in both physiological and pathological contexts. The details of these recent findings, their pathophysiological implications, and the requirements for future research are addressed in this review.
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Affiliation(s)
- Roger Harrison
- Department of Biology and Biochemistry, University of Bath, Bath, UK.
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Pritsos CA. Cellular distribution, metabolism and regulation of the xanthine oxidoreductase enzyme system. Chem Biol Interact 2000; 129:195-208. [PMID: 11154741 DOI: 10.1016/s0009-2797(00)00203-9] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Xanthine oxidase (EC 1.1.3.22) and xanthine dehydrogenase (EC 1.1.1. 204) are both members of the molybdenum hydroxylase flavoprotein family and represent different forms of the same gene product. The two enzyme forms and their reactions are often referred to as xanthine oxidoreductase (XOR) activity. Physiologically, XOR is known as the rate-limiting enzyme in purine catabolism but has also been shown to be able to metabolize a number of other physiological compounds. Recent studies have also demonstrated its ability to metabolize xenobiotics, including a number of anticancer compounds, to their active metabolites. During the past 10 years, evidence has mounted to support a role for XOR in the pathophysiology of inflammatory diseases and atherosclerosis as well as its previously determined role in ischemia-reperfusion injury. While significant progress has recently been made in our understanding of the physiological and biochemical nature of this enzyme system, considerable work still needs to be done. This paper will review some of the more recent work characterizing the interactions and the factors that influence the interactions of XOR with various physiological and xenobiotic compounds.
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Affiliation(s)
- C A Pritsos
- Department of Nutrition, Center for Environmental Sciences and Engineering, MS 199, University of Nevada, Reno, NV 89557, USA.
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17
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Martelin E, Palvimo JJ, Lapatto R, Raivio KO. Nuclear factor Y activates the human xanthine oxidoreductase gene promoter. FEBS Lett 2000; 480:84-8. [PMID: 11034305 DOI: 10.1016/s0014-5793(00)01909-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To study the regulation of the human xanthine oxidoreductase (XOR) gene, we cloned 1.9 kb of the promoter region. In reporter gene assays, a construct encompassing nucleotides between 142 to +42 conferred maximal basal activity of the XOR promoter in 293T cells, in comparison with shorter (-92 to +42) or longer (up to -1937 to +42) constructs. The promoter activity was low in NIH-3T3 cells. The most active construct contained a putative CCAAT motif at -119 to -123. Electrophoretic mobility shift assays showed that this sequence binds the ubiquitous nuclear factor Y (NF-Y). Mutation of the CCAAT motif (CTGAT) abolished the NF-Y binding and considerably reduced the promoter activity. Our data suggest an important functional role for NF-Y in the transcriptional activation of the human XOR gene.
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Affiliation(s)
- E Martelin
- Hospital for Children and Adolescents, Research Laboratory, University of Helsinki, Finland.
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18
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Segal BH, Sakamoto N, Patel M, Maemura K, Klein AS, Holland SM, Bulkley GB. Xanthine oxidase contributes to host defense against Burkholderia cepacia in the p47(phox-/-) mouse model of chronic granulomatous disease. Infect Immun 2000; 68:2374-8. [PMID: 10722648 PMCID: PMC97432 DOI: 10.1128/iai.68.4.2374-2378.2000] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Chronic granulomatous disease (CGD) is an inherited disorder of the NADPH oxidase in which phagocytes are defective in generating superoxide and downstream microbicidal reactive oxidants, leading to recurrent life-threatening bacterial and fungal infections. Xanthine oxidase (XO) is another enzyme known to produce superoxide in many tissues. Using the p47(phox-/-) mouse model of CGD, we evaluated the residual antibacterial activity of XO. Clearance of Burkholderia cepacia, a major pathogen in CGD, was reduced in p47(phox-/-) mice compared to that in wild-type mice and was further inhibited in p47(phox-/-) mice by pretreatment with the specific XO inhibitor allopurinol. Hepatic B. cepacia burden was similar in the two genotypes, but allopurinol significantly reduced net hepatic killing and killing efficiency only in p47(phox-/-) mice. Clearance and killing of intravenous Escherichia coli was intact in p47(phox-/-) mice and was unaffected by pretreatment with allopurinol. In CGD, XO may contribute to host defense against a subset of reactive oxidant-sensitive pathogens.
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Affiliation(s)
- B H Segal
- Laboratory of Host Defenses, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
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19
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Xu P, LaVallee P, Hoidal JR. Repressed expression of the human xanthine oxidoreductase gene. E-box and TATA-like elements restrict ground state transcriptional activity. J Biol Chem 2000; 275:5918-26. [PMID: 10681584 DOI: 10.1074/jbc.275.8.5918] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Studies were initiated to address the basis for the low xanthine oxidoreductase (XOR) activity in humans relative to nonprimate mammalian species. The expression of the XOR in humans is strikingly lower than in mice, and both transcription rates and core promoter activity of the gene are repressed. Analysis of human XOR promoter activity in hepatocytes and vascular endothelial cells showed that the region from -258 to -1 contains both repressor and activator binding regions regulating core promoter activity. The region between -138 and -1 is necessary and sufficient for initiating, and the region between -258 and -228 is critical for restricting core promoter activity. Within the latter region, site-directed mutations identified a consensus sequence "acacaggtgtgg" (-242 to -230) that contains an E-box that binds a repressor. In addition, the TATA-like element is also required to restrict promoter activity and TFIID binds to this site. The results demonstrate that both an E-box and TATA-like element are required to restrict gene activity. A model is proposed to account for human XOR regulation.
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Affiliation(s)
- P Xu
- Department of Internal Medicine, Division of Respiratory, Critical Care and Occupational Medicine, University of Utah Health Sciences Center and Veterans Affairs Medical Center, Salt Lake City, Utah 84132, USA
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20
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Abstract
The characteristics and possible functions of the most abundant proteins associated with the bovine milk-fat globule membrane are reviewed. Under the auspices of the Milk Protein Nomenclature Committee of the ADSA, a revised nomenclature for the major membrane proteins is proposed and discussed in relation to earlier schemes. We recommend that proteins be assigned specific names as they are identified by molecular cloning and sequencing techniques. The practice of identifying proteins according to their Mr, electrophoretic mobility, or staining characteristics should be discontinued, except for uncharacterized proteins. The properties and amino acid sequences of the following proteins are discussed in detail: MUC1, xanthine dehydrogenase/oxidase, CD36, butyrophilin, adipophilin, periodic acid Schiff 6/7 (PAS 6/7), and fatty acid binding protein. In addition, a compilation of less abundant proteins associated with the bovine milk-fat globule membrane is presented.
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Affiliation(s)
- I H Mather
- Department of Animal and Avian Sciences, University of Maryland, College Park 20742, USA.
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21
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Skulachev VP. Mitochondrial physiology and pathology; concepts of programmed death of organelles, cells and organisms. Mol Aspects Med 1999; 20:139-84. [PMID: 10626278 DOI: 10.1016/s0098-2997(99)00008-4] [Citation(s) in RCA: 202] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The review summarizes the present state of our knowledge concerning alternative functions of mitochondria, namely energy conservation in forms of protonic potential and ATP, thermoregulatory energy dissipation as heat, production of useful substances, decomposition of harmful substances, control of cellular processes. The recent progress in understanding of some mitochondrion-linked pathologies is described. The role of reactive oxygen species in these processes is stressed. Possible mechanisms of programmed death of mitochondrion (mitoptosis), cell (apoptosis) and organism (phenoptosis) are considered. A concept is put forward assuming that mitoptosis is involved in some types of apoptosis whereas apoptosis can be a part of a phenoptotic cascade. It is hypothesized that septic shock, as well as the stress-induced brain and heart ischemic diseases and cancer, exemplify mechanisms of phenoptosis purifying population, community of organisms or kin from dangerous or useless individuals.
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Affiliation(s)
- V P Skulachev
- Department of Bioenergetics, A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russian Federation.
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22
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Moriwaki Y, Yamamoto T, Yamakita J, Takahashi S, Tsutsumi Z, Higashino K. Effect of interferon-gamma on purine catabolic and salvage enzyme activities in rats. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1427:385-91. [PMID: 10350654 DOI: 10.1016/s0304-4165(99)00038-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To determine whether interferon-gamma affects rat purine catabolic and salvage enzyme activities, rats were injected with interferon-gamma (600000 U/kg, i.p.) and, similarly to a vehicle-injected control group, killed before or after injection at 6, 12, and 24 h. Organ homogenates were prepared and enzymatic reactions with substrates were carried out, after which the products were measured either chromatographically or spectrophotometrically. Western and Northern blotting also were performed. In contrast to the vehicle-injected rats, interferon-gamma-injected rats showed a significant rise in xanthine oxidoreductase activity in the liver, while enzyme activity was unchanged in the spleen, kidney, and lung. Western analysis of hepatic xanthine oxidoreductase showed an increased concentration of this protein 12 and 24 h after interferon-gamma injection. Northern analysis disclosed an enhanced mRNA expression coding for this enzyme, peaking 12 h after injection. Contrastingly, the activities of adenosine deaminase, purine nucleoside phosphorylase, hypoxanthine guanine phosphoribosyltransferase, and adenine phosphoribosyltransferase were not affected by interferon-gamma in any organ tested. While interferon-gamma causes an increased hepatic biosynthesis of xanthine oxidoreductase, the physiologic role of this enzyme induction remains undetermined.
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Affiliation(s)
- Y Moriwaki
- Third Department of Internal Medicine, Hyogo College of Medicine, Mukogawa-cho 1-1, Nishinomiya, Hyogo 663-8501, Japan
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23
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Clark MP, Chow CW, Rinaldo JE, Chalkley R. Multiple domains for initiator binding proteins TFII-I and YY-1 are present in the initiator and upstream regions of the rat XDH/XO TATA-less promoter. Nucleic Acids Res 1998; 26:2813-20. [PMID: 9592172 PMCID: PMC147594 DOI: 10.1093/nar/26.11.2813] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We previously reported that the TATA-less rat xanthine dehydrogenase/oxidase (XDH/XO) promoter is organized with multiple initiator elements (Inr 1, 2, 3 and 4). Additionally, we identified six factor binding footprints in the upstream region of this promoter (FP 1-FP 6), two of which (FP 2 and FP 4) we showed to be C/EBP binding sites. In this report we continue our characterization of the XDH/XO promoter, detailing other cis elements which comprise the Inr and upstream binding factors. Interestingly, multiple binding domains for known initiator binding proteins, YY-1 and USF-related factor/TFII-I, have been identified which potentially play an important role in transcription initiation.
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Affiliation(s)
- M P Clark
- Nashville VA Medical Center, Department of Medicine, School of Medicine, Vanderbilt University, Nashville, TN 37237, USA
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24
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Parks DA, Skinner KA, Skinner HB, Tan S. Multiple organ dysfunction syndrome: Role of xanthine oxidase and nitric oxide. PATHOPHYSIOLOGY 1998. [DOI: 10.1016/s0928-4680(98)00008-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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25
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Clark MP, Chow CW, Rinaldo JE, Chalkley R. Correct usage of multiple transcription initiation sites and C/EBP-dependent transcription activation of the rat XDH/XO TATA-less promoter requires downstream elements located in the coding region of the gene. Nucleic Acids Res 1998; 26:1801-6. [PMID: 9512555 PMCID: PMC147445 DOI: 10.1093/nar/26.7.1801] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In the present study, we have shown that a downstream element located in the coding region of the TATA-less rat xanthine dehydrogenase/oxidase (XDH/XO) gene (-7 to +42) plays an important role in transcription initiation and C/EBP transcriptional activation. Previous work from our laboratory has shown that the promoter is organized with multiple initiator elements (Inr 1, 2, 3 and 4) which are important for transcription initiation. Additionally, we had identified two C/EBP binding sites upstream of this promoter. Deletional and mutational studies revealed that C/EBP binding was not essential for the basal level of transcriptional initation. However when XO-luciferase constructs include downstream sequence extending to +42 there is development of C/EBP sensitivity as well as a shift in the initiator usage. In the absence of the downstream element, primer extension analyses reveals Inr 3 and 4 to be the major start sites but in the presence of this additional sequence the usage is shifted to Inr 1 and 2. This shift in Inr usage more closely resembles that seen in intact macrophages or liver cells. Gel mobility shift assays indicate the presence of several binding factors located in this downstream region, one of which has been identified as YY-1. We postulate that YY-1 allows DNA bending which permits the upstream C/EBP elements to exhibit a transcriptional activation which is not seen when the downstream element is absent. This study presents a potential model for regulation of the XDH/XO promoter.
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Affiliation(s)
- M P Clark
- Department of Medicine, School of Medicine, Vanderbilt University, Nashville, TN 37232, USA
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26
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Terada LS, Piermattei D, Shibao GN, McManaman JL, Wright RM. Hypoxia regulates xanthine dehydrogenase activity at pre- and posttranslational levels. Arch Biochem Biophys 1997; 348:163-8. [PMID: 9390187 DOI: 10.1006/abbi.1997.0367] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hypoxia increases the activity of xanthine oxidase (XO) and its precursor, xanthine dehydrogenase (XDH), but the mechanism of regulation is unclear. In hypoxic Swiss 3T3 cells, an early (0-24 h) cycloheximide-insensitive increase in XO-XDH activity, coupled with a lack of increase in de novo XO-XDH synthesis (immunoprecipitation) or mRNA levels (quantitative RT-PCR), demonstrated a posttranslational effect of hypoxia. Similarly, hyperoxia decreased XO-XDH activity faster than could be accounted for by cessation of XO-XDH protein synthesis. In further support of a posttranslational effect, cells transfected with a constitutively driven XDH construct displayed an exaggerated increase in activity in hypoxia but no increase in activity in hyperoxia. However, more prolonged exposure to hypoxia (24-48 h) induced an increase in XO-XDH mRNA levels and de novo XO-XDH protein synthesis, suggesting an additional pretranslational effect. Finally, hypoxic induction of XO-XDH activity was found to be cell-type-restricted. We conclude that control of XO-XDH levels by oxygen tension is a complex process which involves several points of regulation.
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Affiliation(s)
- L S Terada
- Webb-Waring Institute for Biomedical Research, University of Colorado Health Sciences Center, Denver 80262, USA.
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27
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Umezawa K, Akaike T, Fujii S, Suga M, Setoguchi K, Ozawa A, Maeda H. Induction of nitric oxide synthesis and xanthine oxidase and their roles in the antimicrobial mechanism against Salmonella typhimurium infection in mice. Infect Immun 1997; 65:2932-40. [PMID: 9199469 PMCID: PMC175411 DOI: 10.1128/iai.65.7.2932-2940.1997] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The role of superoxide anion (O2-) and nitric oxide (NO) in the host defense mechanism against Salmonella typhimurium (LT-2) was examined by focusing on xanthine oxidase (XO) as an O2(-)-generating system and on inducible NO synthase (iNOS). When ICR mice were infected with a 0.1 50% lethal dose (2 x 10(5) CFU) of S. typhimurium, bacterial growth in the liver reached a peak value 3 days after infection (10(4.32) CFU/g of liver) and decreased thereafter. XO activity in the liver became maximum at 7 days after infection; the value was 34.6 +/- 1.4 mU/g of liver at 7 days (compared with 11.0 +/- 1.3 mU/g of liver before infection). The time profile of NO production in the liver as determined by electron spin resonance spectroscopy was consistent with that of XO activity. Histological examination of infected liver showed the formation of multiple microabscesses with granulomatous lesions consisting of polymorphonuclear cells and mononuclear cells, and iNOS-expressing cells were localized in the confined areas of the microabscesses. When XO inhibitors such as allopurinol and 4-amino-6-hydroxypyrazolo[3,4-d]pyrimidine (AHPP) were administered to the infected mice, the mortality of the mice was significantly increased (10 of 21 and 11 of 20 for the allopurinol- and AHPP-treated groups, respectively, versus 2 of 20 for control mice), and bacterial growth was significantly enhanced. A similar exacerbation of the infection was obtained with N(omega)-monomethyl-L-arginine (L-NMMA) treatment of the mice. Of considerable importance is that granuloma formation in the liver was poorly developed by treatment with either XO inhibitors or L-NMMA. These results suggest that XO and NO play an important role in the antimicrobial mechanism against S. typhimurium in mice.
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Affiliation(s)
- K Umezawa
- Department of Microbiology, Kumamoto University School of Medicine, Honjo, Japan
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28
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Abstract
Abstract
Treatment of freshly isolated acute promyelocytic leukemia (APL) cells and the myelogenous leukemia cell lines, NB4, HL-60, and U937, with all-trans retinoic acid (ATRA) results in a remarkable elevation in the amounts of Stat1α and Stat2 proteins. Stat1α protein levels are augmented by ATRA as a consequence of elevated amounts of the corresponding transcripts. The retinoid increases the levels of nuclear complexes that are capable of binding to interferon (IFN)-regulated consensus sequences and contain Stat1 and/or Stat2 proteins, and causes a rapid and long-lasting elevation in Stat1α tyrosine phosphorylation. Transient transfection experiments show that ATRA enhances the transactivating properties of Stat1α observed on an appropriate reporter gene, in the presence of the RARα retinoic acid receptor, but not in the presence of the PML-RAR protein. Treatment of NB4 cells with ATRA is associated with a remarkable upregulation of the two IFN-responsive genes IFN-responsive factor 1 and 2′-5′ oligoadenylate synthetase, as well as with an augmentation in the levels of IFNα secretion. Our data show that ATRA is capable of modulating the amounts and the state of activation of some of the components of the IFN intracellular signaling pathways. They also suggest that the retinoid can bypass IFN/IFN-receptor interactions and induce the expression of IFN-regulated genes.
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29
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Hellsten Y, Frandsen U, Orthenblad N, Sjødin B, Richter EA. Xanthine oxidase in human skeletal muscle following eccentric exercise: a role in inflammation. J Physiol 1997; 498 ( Pt 1):239-48. [PMID: 9023782 PMCID: PMC1159248 DOI: 10.1113/jphysiol.1997.sp021855] [Citation(s) in RCA: 152] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
1. The present study tested the hypothesis that the level of xanthine oxidase is elevated in injured human skeletal muscle in association with inflammatory events. Seven male subjects performed five bouts of strenuous one-legged eccentric exercise. Muscle biopsies from both the exercised and the control leg, together with venous blood samples, were obtained prior to exercise and at 45 min, 24, 48 and 96 h after exercise. The time courses of xanthine oxidase immunoreactivity and indicators of muscle damage and inflammation were examined. 2. The number of xanthine oxidase structures observed by immunohistological methods in the exercised muscle was up to eightfold higher than control from day 1 to day 4 after exercise (P < 0.05). The increase was attributed to an enhanced expression of xanthine oxidase in microvascular endothelial cells and an invasion of leucocytes containing xanthine oxidase. 3. The concentration of plasma interleukin-6 was significantly higher 90 min after exercise than before exercise (P < 0.05) and remained higher than pre-exercise levels throughout the 4 days. On day 4 the plasma creatine kinase activity was approximately 150-fold higher (P < 0.05) than resting levels. 4. Despite the increase in xanthine oxidase in the muscle there were no detectable changes in the levels of muscle malondialdehyde or in plasma antioxidant capacity up to 4 days post-exercise. 5. It is concluded that eccentric exercise leads to an increased level of xanthine oxidase in human muscle and that the increase is associated with secondary inflammatory processes. The increase in xanthine oxidase in the muscle occurs mainly in microvascular endothelial cells, but occurs also via infiltrating leucocytes containing xanthine oxidase. A role for leucocytes in xanthine oxidase induction in endothelium is proposed.
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Affiliation(s)
- Y Hellsten
- Copenhagen Muscle Research Centre, August Krogh Institute, Denmark.
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30
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Kurosaki M, Zanotta S, Li Calzi M, Garattini E, Terao M. Expression of xanthine oxidoreductase in mouse mammary epithelium during pregnancy and lactation: regulation of gene expression by glucocorticoids and prolactin. Biochem J 1996; 319 ( Pt 3):801-10. [PMID: 8920983 PMCID: PMC1217859 DOI: 10.1042/bj3190801] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In the mammary gland of virgin mice, xanthine oxidoreductase (XOR) enzymic activity is barely measurable. a high increase in the levels of the enzyme is observed during the last days of pregnancy and during lactation, and this is parallelled by an elevation in the amounts of the respective protein and transcript. In situ hybridization experiments demonstrate that the XOR mRNA is specifically expressed in the alveolar epithelial cells of the mammary gland. In HC11 cells, a model culture system for normal breast epithelium, the levels of XOR enzymic activity are dose- and time-dependently induced by dexamethasone, and a further synergistic augmentation is observed in the presence of dexamethasone plus prolactin. Increased XOR gene expression is consequent on glucocorticoid receptor activation, as indicated by sensitivity to the specific receptor antagonist RU486. In addition, the phenomenon is likely to involve protein phosphorylation and dephosphorylation events, as suggested by modulation of XOR mRNA by tyrosine kinase and phosphatase inhibitors.
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Affiliation(s)
- M Kurosaki
- Molecular Biology Unit, istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy
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31
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Abstract
Hyperuricemia is associated with the severity of preeclampsia and with fetal outcome. Traditionally the high uric acid concentration in preeclampsia has been attributed soley to renal dysfunction. Preeclampsia is also characterized by increased free radical formation and elevated oxidative stress. Xanthine dehydrogenase/oxidase produces uric acid. Xanthine dehydrogenase/oxidase is present as two isoforms in vivo. Uric acid production is coupled with formation of reactive oxygen species when the enzyme is in the oxidase form. Several factors can increase the holoenzyme activity and the conversion of xanthine dehydrogenase/oxidase to its oxidase form. These factors include hypoxia-reperfusion, cytokines, and increased substrate availability (xanthine and hypoxanthine). Preeclampsia is characterized by hyperuricemia and signs of increased formation of reactive oxygen species and decreased levels of antioxidants. Preeclampsia is also characterized by shallow implantation, producing a relatively hypoxic maternal-fetal interface, and increased turnover of trophoblast tissue, which can result in higher xanthine and hypoxanthine concentrations and higher levels of circulating cytokines. These mechanisms can lead to increased production of uric acid and free radicals and contribute to the hyperuricemia and increased oxidative stress present in preeclampsia.
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Affiliation(s)
- A Many
- Magee Womens Research Institute, Pittsburgh, PA 15213, USA
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32
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Chow CW, Clark MP, Rinaldo JE, Chalkley R. Multiple initiators and C/EBP binding sites are involved in transcription from the TATA-less rat XDH/XO basal promoter. Nucleic Acids Res 1995; 23:3132-40. [PMID: 7667089 PMCID: PMC307170 DOI: 10.1093/nar/23.16.3132] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
In the present study, we have explored further the organization of the TATA-less rat xanthine dehydrogenase/oxidase gene (XDH/XO). A DNase I hypersensitive site has been identified which it colocalizes with the basal promoter reported previously [Chow et al. (1994) Nucleic Acids Res., 22, 1846-1854]. Gel mobility shift assays indicate the presence of multiple binding factors located in the promoter. At least six footprints were detected of which two have been shown to be C/EBP binding sites. Members of the C/EBP-alpha and C/EBP-beta, but not C/EBP-delta, family are able to bind to these two sites. Deletional and mutational studies revealed that C/EBP binding is not essential for the basal level of transcription initiation of this promoter. Much of the transcriptional activity resides in the -102 to -7 DNA fragment, which contains all initiator activity which acts unidirectionally. Within this fragment, four putative initiator elements could be identified; interestingly, the linear integrity of these initiators is important for efficient transcription of the XDH/XO gene. Separation of the initiators leads to a complete loss of transcription activity; however, this loss could be partially restored by the introduction of an Sp1 binding site upstream of the separated initiators. Despite a difference in usage/frequency of initiation at the various initiators, primer extension analyses reveal similar positions for transcription initiations in both XDH/XO reporter constructs and in the endogenous XDH/XO gene. The differential usage of initiators may imply a possible post-transcriptional regulation for the XDH/XO gene.
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Affiliation(s)
- C W Chow
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, TN 37232, USA
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33
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Shaw T, Locarnini SA. Hepatic purine and pyrimidine metabolism: implications for antiviral chemotherapy of viral hepatitis. LIVER 1995; 15:169-84. [PMID: 8544639 DOI: 10.1111/j.1600-0676.1995.tb00667.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The use of nucleoside analogues as antiviral agents is expanding. For most nucleoside analogues, intracellular phosphorylation is the major prerequisite for activity. Antiviral activity may be limited by poor uptake, absence of appropriate activating enzymes, catabolism, and competition from endogenous nucleotides. Appreciation of these factors, which are species-, tissue- and cell-specific is important in the understanding of the pharmacology and toxicology of nucleoside analogues. The use of nucleoside analogues against the agents of viral hepatitis is inherently problematic for many reasons including active hepatic nucleoside catabolism, probable absence of virus-specific activating enzymes, competition from endogenous nucleotides synthesised de novo or derived from RNA turnover, and factors related to mitochondrial toxicity. Despite these drawbacks, some nucleoside analogues have been found efficacious against hepatitis B virus and it is likely that as knowledge of their mechanism of action accumulates, their efficacy can be improved both by rational drug design and by use in combination with other drugs, including interferon.
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Affiliation(s)
- T Shaw
- Macfarlane Burnet Centre for Medical Research, Fairfield Hospital, Victoria, Australia
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34
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Kooij A. A re-evaluation of the tissue distribution and physiology of xanthine oxidoreductase. ACTA ACUST UNITED AC 1995. [PMID: 7896566 DOI: 10.1007/bf02388567] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Xanthine oxidoreductase is an enzyme which has the unusual property that it can exist in a dehydrogenase form which uses NAD+ and an oxidase form which uses oxygen as electron acceptor. Both forms have a high affinity for hypoxanthine and xanthine as substrates. In addition, conversion of one form to the other may occur under different conditions. The exact function of the enzyme is still unknown but it seems to play a role in purine catabolism, detoxification of xenobiotics and antioxidant capacity by producing urate. The oxidase form produces reactive oxygen species and, therefore, the enzyme is thought to be involved in various pathological processes such as tissue injury due to ischaemia followed by reperfusion, but its role is still a matter of debate. The present review summarizes information that has become available about the enzyme. Interpretations of contradictory findings are presented in order to reduce confusion that still exists with respect to the role of this enzyme in physiology and pathology.
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Affiliation(s)
- A Kooij
- Academic Medical Centre, University of Amsterdam, The Netherlands
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35
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Kurosaki M, Li Calzi M, Scanziani E, Garattini E, Terao M. Tissue- and cell-specific expression of mouse xanthine oxidoreductase gene in vivo: regulation by bacterial lipopolysaccharide. Biochem J 1995; 306 ( Pt 1):225-34. [PMID: 7864814 PMCID: PMC1136505 DOI: 10.1042/bj3060225] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The expression of the xanthine oxidoreductase gene was studied in various mouse organs and tissues, under basal conditions and on treatment with bacterial lipopolysaccharide. Levels of xanthine oxidoreductase protein and mRNA were compared in order to understand the molecular mechanisms regulating the expression of this enzyme system. The highest amounts of xanthine oxidoreductase and the respective mRNA are observed in the duodenum and jejunum, where the protein is present in an unusual form because of a specific proteolytic cleavage of the primary translation product present in all locations. Under basal conditions, multiple tissue-specific mechanisms of xanthine oxidoreductase regulation are evident. Lipopolysaccharide increases enzyme activity in some, but not all tissues, mainly via modulation of the respective transcript, although translational and post-translational mechanisms are also active. In situ hybridization studies on tissue sections obtained from mice under control conditions or with lipopolysaccharide treatment demonstrate that xanthine oxidoreductase is present in hepatocytes, predominantly in the proximal tubules of the kidney, epithelial layer of the gastrointestinal mucosa, the alveolar compartment of the lung, the pulpar region of the spleen and the vascular component of the heart.
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Affiliation(s)
- M Kurosaki
- Molecular Biology Unit, Centro Daniela e Catullo Borgomainerio, Istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy
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Chow CW, Clark M, Rinaldo J, Chalkley R. Identification of the rat xanthine dehydrogenase/oxidase promoter. Nucleic Acids Res 1994; 22:1846-54. [PMID: 8208609 PMCID: PMC308083 DOI: 10.1093/nar/22.10.1846] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Inflammation and ischemia--reperfusion tissue injury are important pathophysiologic processes with a wide spectrum of clinical presentations; the enzyme xanthine dehydrogenase/oxidase (XDH/XO) is thought to play a key role in ischemia--reperfusion injury. Recent studies have shown the transcriptional regulation of XDH/XO by cytokines (Dupont et al., 1992, J. Clin. Invest. 89, 197-202). In the present study, the 5' structure of the XDH/XO gene and characterization of its promoter are undertaken providing an initial step to further elucidate the regulatory mechanism(s) of this enzyme. XDH/XO cDNA from rat bone marrow macrophage has been isolated and used to screen a rat genomic library in order to identify and characterize the promoter of the XDH/XO gene. By Southern analysis, XDH/XO was found to be a single copy gene in the rat genome. Primer extension, RNase protection, and anchor-PCR studies indicate the presence of multiple start sites within a 65 bp window located some 20-85 bp upstream of the translation initiator (ATG). Functional studies of the sequences up to 116 nt upstream of the translational start site, which encompasses the several transcriptional start sites, indicate that this region is sufficient to drive the expression of a luciferase reporter gene and is presumed to represent the promoter. Neither a TATA box nor a GC-rich region are present in close proximity to any of the transcriptional start sites; however, sequences with homology to known initiator elements are found within this 116 bp fragment. Several possible regulatory elements, including a NF-IL6 motif, are also located upstream of the transcriptional start site. This study represents the first description of the XDH/XO promoter from a vertebrate system.
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Affiliation(s)
- C W Chow
- Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, TN 37232
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Falciani F, Terao M, Goldwurm S, Ronchi A, Gatti A, Minoia C, Li Calzi M, Salmona M, Cazzaniga G, Garattini E. Molybdenum(VI) salts convert the xanthine oxidoreductase apoprotein into the active enzyme in mouse L929 fibroblastic cells. Biochem J 1994; 298 ( Pt 1):69-77. [PMID: 8129733 PMCID: PMC1137984 DOI: 10.1042/bj2980069] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The mouse L929 fibroblastic cell line presents low, but detectable, levels of the mRNA encoding xanthine oxidoreductase under basal conditions, and it responds to type I and type II interferons by inducing the expression of the transcript [Falciani, Ghezzi, Terao, Cazzaniga, and Garattini (1992) Biochem. J. 285, 1001-1008]. This cell line, however, does not show any detectable amount of xanthine oxidoreductase enzymic activity, either before or after treatment with the cytokines. Molybdenum(VI) salts, in the millimolar range, are capable of activating xanthine oxidoreductase in L929 cells both under basal conditions and after treatment with interferon-alpha. The increase is observed in mouse L929 as well as in clones derived from it, but not in many other human and mouse cell lines. The induction observed in L929 cells is post-translational in nature and it is insensitive to cycloheximide, indicating that the molybdenum ion converts a pool of inactive xanthine oxidoreductase apoenzyme into its holoenzymic form. When grown in the absence of sodium molybdate, the L929 cell line has undetectable intracellular levels of the molybdenum cofactor, since the cell extracts are unable to complement the nitrate reductase defect of the nit-1 mutant of Neurospora crassa. L929 cells grown in the presence of millimolar concentrations of sodium molybdate, however, become competent to complement the nit-1 defect. L929 cells accumulate molybdenum ion inside the intracellular compartment as efficiently as TEnd cells, a mouse endothelial cell line that expresses xanthine oxidoreductase activity both under basal conditions and after treatment with interferon-gamma, suggesting that L929 cells have a defect in one or more of the metabolic steps leading to the synthesis of the molybdenum cofactor.
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Affiliation(s)
- F Falciani
- Molecular Biology Unit, Centro Daniela e Catullo Borgomainerio, Istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy
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Conde M, Andrade J, Bedoya FJ, Sobrino F. Inhibitory effect of interferon-alpha on respiratory burst and glucose metabolism in phagocytic cells. JOURNAL OF INTERFERON RESEARCH 1994; 14:11-6. [PMID: 8027589 DOI: 10.1089/jir.1994.14.11] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Anion superoxide (O2-) production and glucose metabolism was studied in murine macrophages following in vivo or in vitro treatment with human recombinant interferon-alpha 2b (IFN-alpha 2b). The PMA-dependent O2- production was inhibited by IFN-alpha 2b in a concentration- and time-dependent manner. NO2- production by macrophages in culture was slightly inhibited (about 16%) at 30 nM IFN-alpha and a clear decrease (35%) was obtained with 150 nM IFN-alpha. Low doses (0.3 and 3 nM IFN-alpha) had no effect. Also, IFN-alpha 2b inhibited lactate release and 3H2O production from [2-3H] and [3-3H]glucose in macrophages isolated after in vivo treatment for 24 h. The data support an inhibitory role of IFN-alpha in the metabolic activation of macrophages and suggest a putative mechanism for the inhibition of some macrophage functions as previously reported.
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Affiliation(s)
- M Conde
- Dept. Bioquímica Médica y Biología Molecular, Facultad de Medicina, Universidad de Sevilla, Spain
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Terada LS, Arnold PD. Xanthine oxidase does not mediate the antiproliferative effects of interferon-gamma in human umbilical vein endothelial cells. JOURNAL OF INTERFERON RESEARCH 1993; 13:419-22. [PMID: 8151136 DOI: 10.1089/jir.1993.13.419] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Interferon-gamma (IFN-gamma) has potent antiproliferative effects on the endothelium, although the specific mechanisms responsible for this effect are not clear. We tested the hypothesis that suppression of endothelial cell proliferation by IFN-gamma is mediated by an increase in xanthine oxidase-derived O2-.. Human umbilical vein endothelial cells (HUVEC) were exposed to recombinant human IFN-gamma. We found that [3H]thymidine uptake decreased (p < 0.05) with increasing doses of IFN-gamma. Treatment of HUVEC with the xanthine oxidase inhibitor allopurinol or the O2-. scavenger superoxide dismutase had no effect (p > 0.05) on [3H]thymidine uptake of IFN-gamma-treated cells. In parallel, IFN-gamma decreased (p < 0.05) HUVEC cell counts, while allopurinol again had no effect (p > 0.05) on cell counts of IFN-gamma-treated or control HUVEC. In addition, xanthine oxidase activity of HUVEC did not (p > 0.05) increase following treatment with IFN-gamma. We conclude that IFN-gamma suppresses HUVEC proliferation by a mechanism independent of O2-. production by xanthine oxidase.
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Affiliation(s)
- L S Terada
- Webb-Waring Institute for Biomedical Research, University of Colorado Health Sciences Center, Denver 80262
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Lembo D, Gaboli M, Caliendo A, Falciani F, Garattini E, Landolfo S. Regulation of the 202 gene expression by interferons in L929 cells. Biochem Biophys Res Commun 1992; 187:628-34. [PMID: 1382418 DOI: 10.1016/0006-291x(92)91241-h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Type I and II interferons (IFNs) stimulate the expression of the 202 and 2'-5' oligoadenylate synthetase (OASE) genes in L929, NIH 3T3 and LM-TK- fibroblastic cell lines. In two other cell lines, B16 melanoma and F9 teratocarcinoma, these cytokines induce OASE but not the 202 mRNA. In L929 cells, IFN-alpha induces the 202 mRNA at concentrations between 10 and 10(3) units/ml. To achieve maximal induction of the 202 mRNA, continuous exposure of L929 cells to IFN-alpha is necessary, whereas 30 minutes of exposure are sufficient to trigger maximal upregulation of the OASE transcript. The induction of the 202 mRNA is the consequence of both transcriptional and post-transcriptional events. Cycloheximide, a known inhibitor of protein synthesis, does not block the induction of 202 mRNA by IFN-alpha, demonstrating that new protein synthesis is not required for this effect. Protein kinase C, arachidonic acid metabolism via the cyclooxygenase or the lipoxygenase pathways and cAMP are not involved as second messengers in the induction of the 202 mRNA by IFN-alpha in L929 cells.
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Affiliation(s)
- D Lembo
- Istituto di Microbiologia, Facolta di Medicina, Università degli Studi di Torino, Italy
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