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Kaltsas A, Zikopoulos A, Dimitriadis F, Sheshi D, Politis M, Moustakli E, Symeonidis EN, Chrisofos M, Sofikitis N, Zachariou A. Oxidative Stress and Erectile Dysfunction: Pathophysiology, Impacts, and Potential Treatments. Curr Issues Mol Biol 2024; 46:8807-8834. [PMID: 39194738 DOI: 10.3390/cimb46080521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2024] [Revised: 08/01/2024] [Accepted: 08/13/2024] [Indexed: 08/29/2024] Open
Abstract
Erectile dysfunction (ED) is a prevalent condition affecting men's sexual health, with oxidative stress (OS) having recently been identified as a significant contributing causative factor. This narrative review aims to elucidate the role of OS in the pathophysiology of ED, focusing on impact, mechanisms, and potential therapeutic interventions. Key findings indicate that OS disrupts endothelial function and nitric oxide (NO) signaling, crucial for erectile function. Various sources of reactive oxygen species (ROS) and their detrimental effects on penile tissue are discussed, including aging, diabetes mellitus, hypertension, hyperlipidemia, smoking, obesity, alcohol consumption, psychological stress, hyperhomocysteinemia, chronic kidney disease, and sickle cell disease. Major sources of ROS, such as NADPH oxidase, xanthine oxidase, uncoupled endothelial NO synthase (eNOS), and mitochondrial electron transport, are identified. NO is scavenged by these ROS, leading to endothelial dysfunction characterized by reduced NO availability, impaired vasodilation, increased vascular tone, and inflammation. This ultimately results in ED due to decreased blood flow to penile tissue and the inability to achieve or maintain an erection. Furthermore, ROS impact the transmission of nitrergic neurotransmitters by causing the death of nitrergic neurons and reducing the signaling of neuronal NO synthase (nNOS), exacerbating ED. Therapeutic approaches targeting OS, including antioxidants and lifestyle modifications, show promise in ameliorating ED symptoms. The review underscores the need for further research to develop effective treatments, emphasizing the interplay between OS and vascular health in ED. Integrating pharmacological and non-pharmacological strategies could enhance clinical outcomes for ED patients, advocating for OS management in ED treatment protocols to improve patient quality of life.
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Affiliation(s)
- Aris Kaltsas
- Third Department of Urology, Attikon University Hospital, School of Medicine, National and Kapodistrian University of Athens, 12462 Athens, Greece
| | | | - Fotios Dimitriadis
- Department of Urology, Faculty of Medicine, School of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Danja Sheshi
- Department of Urology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece
| | - Magdalena Politis
- Department of Urology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece
| | - Efthalia Moustakli
- Laboratory of Medical Genetics, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece
| | - Evangelos N Symeonidis
- Department of Urology II, European Interbalkan Medical Center, 55535 Thessaloniki, Greece
| | - Michael Chrisofos
- Third Department of Urology, Attikon University Hospital, School of Medicine, National and Kapodistrian University of Athens, 12462 Athens, Greece
| | - Nikolaos Sofikitis
- Department of Urology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece
| | - Athanasios Zachariou
- Department of Urology, Faculty of Medicine, School of Health Sciences, University of Ioannina, 45110 Ioannina, Greece
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2
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Gupta M, Meehan-Atrash J, Strongin RM. Identifying a role for the interaction of homocysteine and copper in promoting cardiovascular-related damage. Amino Acids 2021; 53:739-744. [PMID: 33886000 DOI: 10.1007/s00726-021-02979-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 04/03/2021] [Indexed: 12/15/2022]
Abstract
Observations that copper and homocysteine levels are simultaneously elevated in patients with cardiovascular disease has generated interest in investigating the interactions between copper and homocysteine. Several prior studies have shown that complexes of copper and homocysteine are toxic, leading to cardiovascular damage in vitro. It is not clear, however, why related effects do not occur with other structurally similar, more abundant cellular thiols such as glutathione and cysteine. Herein, a mechanism for a selective redox interaction between copper and homocysteine is demonstrated. It involves a kinetically favored intramolecular hydrogen atom transfer that results in an alpha-amino carbon-centered radical known to promote biomolecular damage.
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Affiliation(s)
- Megha Gupta
- Department of Chemistry, Portland State University, Portland, OR, 97207, USA
| | | | - Robert M Strongin
- Department of Chemistry, Portland State University, Portland, OR, 97207, USA.
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3
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Medici V, Kieffer DA, Shibata NM, Chima H, Kim K, Canovas A, Medrano JF, Islas-Trejo AD, Kharbanda KK, Olson K, Su RJ, Islam MS, Syed R, Keen CL, Miller AY, Rutledge JC, Halsted CH, LaSalle JM. Wilson Disease: Epigenetic effects of choline supplementation on phenotype and clinical course in a mouse model. Epigenetics 2016; 11:804-818. [PMID: 27611852 DOI: 10.1080/15592294.2016.1231289] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Wilson disease (WD), a genetic disorder affecting copper transport, is characterized by hepatic and neurological manifestations with variable and often unpredictable presentation. Global DNA methylation in liver was previously modified by dietary choline in tx-j mice, a spontaneous mutant model of WD. We therefore hypothesized that the WD phenotype and hepatic gene expression of tx-j offspring could be modified by maternal methyl supplementation during pregnancy. In an initial experiment, female tx-j mice or wild type mice were fed control or choline-supplemented diets 2 weeks prior to mating through embryonic day 17. Transcriptomic analysis (RNA-seq) on embryonic livers revealed tx-j-specific differences in genes related to oxidative phosphorylation, mitochondrial dysfunction, and the neurological disorders Huntington's disease and Alzheimer disease. Maternal choline supplementation restored the transcript levels of a subset of genes to wild type levels. In a separate experiment, a group of tx-j offspring continued to receive choline-supplemented or control diets, with or without the copper chelator penicillamine (PCA) for 12 weeks until 24 weeks of age. Combined choline supplementation and PCA treatment of 24-week-old tx-j mice was associated with increased liver transcript levels of methionine metabolism and oxidative phosphorylation-related genes. Sex differences in gene expression within each treatment group were also observed. These results demonstrate that the transcriptional changes in oxidative phosphorylation and methionine metabolism genes in WD that originate during fetal life are, in part, prevented by prenatal maternal choline supplementation, a finding with potential relevance to preventive treatments of WD.
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Affiliation(s)
- Valentina Medici
- a Department of Internal Medicine, Division of Gastroenterology and Hepatology , University of California Davis , CA , USA
| | - Dorothy A Kieffer
- a Department of Internal Medicine, Division of Gastroenterology and Hepatology , University of California Davis , CA , USA
| | - Noreene M Shibata
- a Department of Internal Medicine, Division of Gastroenterology and Hepatology , University of California Davis , CA , USA
| | - Harpreet Chima
- b Department of Nutrition , University of California Davis , CA , USA
| | - Kyoungmi Kim
- c Department of Public Health Sciences, Division of Biostatistics , University of California Davis , CA , USA
| | - Angela Canovas
- d Department of Animal Science , University of California Davis , CA , USA
| | - Juan F Medrano
- d Department of Animal Science , University of California Davis , CA , USA
| | - Alma D Islas-Trejo
- d Department of Animal Science , University of California Davis , CA , USA
| | - Kusum K Kharbanda
- e Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System , Omaha , NE , USA
| | - Kristin Olson
- f Department of Pathology , University of California Davis , CA , USA
| | - Ruijun J Su
- f Department of Pathology , University of California Davis , CA , USA
| | - Mohammad S Islam
- g Department of Medical Microbiology and Immunology , Genome Center, and MIND Institute, University of California Davis , CA , USA
| | - Raisa Syed
- a Department of Internal Medicine, Division of Gastroenterology and Hepatology , University of California Davis , CA , USA
| | - Carl L Keen
- b Department of Nutrition , University of California Davis , CA , USA
| | - Amy Y Miller
- h Department of Internal Medicine, Division of Cardiovascular Medicine , University of California Davis , CA , USA
| | - John C Rutledge
- h Department of Internal Medicine, Division of Cardiovascular Medicine , University of California Davis , CA , USA
| | - Charles H Halsted
- a Department of Internal Medicine, Division of Gastroenterology and Hepatology , University of California Davis , CA , USA
| | - Janine M LaSalle
- g Department of Medical Microbiology and Immunology , Genome Center, and MIND Institute, University of California Davis , CA , USA
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4
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Côco H, Pernomian L, Marchi KC, Gomes MS, de Andrade CR, Ramalho LNZ, Tirapelli CR, de Oliveira AM. Consequence of hyperhomocysteinaemia on α1-adrenoceptor-mediated contraction in the rat corpus cavernosum: the role of reactive oxygen species. ACTA ACUST UNITED AC 2016; 68:63-75. [PMID: 26725912 DOI: 10.1111/jphp.12486] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 09/12/2015] [Indexed: 12/11/2022]
Abstract
OBJECTIVES Our main objective was to investigate the mechanisms underlying the effects of hyperhomocysteinaemia (HHcy) on contractile response mediated by α1-adrenoceptors in the rat corpus cavernosum. METHODS Concentration-response curves for phenylephrine (PE) were obtained in strips of corpus cavernosum, in absence or after incubation with tiron, tempol or polyethylene glycol (PEG)-catalase combined or not with tempol. We also measured the superoxide anion (O2(-)) and hydrogen peroxide (H2O2) generation, superoxide dismutase (SOD) and catalase activity and α-actin expression in rat corpus cavernosum from both groups. KEY FINDINGS HHcy increased PE-induced contraction in cavernosal strips. Tiron, PEG-catalase or tempol increased PE-induced contraction in strips from control rats, but it was not altered by tiron or PEG-catalase in HHcy rats, whereas tempol reduced this response. The combination of PEG-catalase and tempol did not alter the contractile response to PE in both groups. HHcy increased O2(-) generation and SOD activity, whereas H2O2 concentration was reduced. Finally, HHcy did not alter catalase activity or expression of α-actin. CONCLUSIONS The major new finding from this study is that HHcy induced a marked increase in PE-induced contraction in rat corpus cavernosum by a mechanism that involves increased O2(-) generation and it could play a role in the pathogenesis of erectile dysfunction associated with HHcy.
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Affiliation(s)
- Hariane Côco
- Departament of Pharmacology, Faculdade de Medicina de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | - Larissa Pernomian
- Laboratory of Vascular Injury, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | - Katia C Marchi
- Departament of Pharmacology, Faculdade de Medicina de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | - Mayara S Gomes
- Laboratory of Vascular Injury, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | - Cláudia R de Andrade
- Department of Pathology and Legal Medicine, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Leandra N Z Ramalho
- Nucleus of Applied Bioprospection and Molecular Research, Faculdades Inta, Fortaleza, CE, Brazil
| | - Carlos R Tirapelli
- Laboratory of Pharmacology, Escola de Enfermagem de Ribeirão Preto, Ribeirão Preto, SP, Brazil
| | - Ana M de Oliveira
- Laboratory of Vascular Injury, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Ribeirão Preto, SP, Brazil
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Cheung CCH, Soon CY, Chuang CL, Phillips ARJ, Zhang S, Cooper GJS. Low-dose copper infusion into the coronary circulation induces acute heart failure in diabetic rats: New mechanism of heart disease. Biochem Pharmacol 2015. [PMID: 26208785 DOI: 10.1016/j.bcp.2015.06.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Diabetes impairs copper (Cu) regulation, causing elevated serum Cu and urinary Cu excretion in patients with established cardiovascular disease; it also causes cardiomyopathy and chronic cardiac impairment linked to defective Cu homeostasis in rats. However, the mechanisms that link impaired Cu regulation to cardiac dysfunction in diabetes are incompletely understood. Chronic treatment with triethylenetetramine (TETA), a Cu²⁺-selective chelator, improves cardiac function in diabetic patients, and in rats with heart disease; the latter displayed ∼3-fold elevations in free Cu²⁺ in the coronary effluent when TETA was infused into their coronary arteries. To further study the nature of defective cardiac Cu regulation in diabetes, we employed an isolated-perfused, working-heart model in which we infused micromolar doses of Cu²⁺ into the coronary arteries and measured acute effects on cardiac function in diabetic and non-diabetic-control rats. Infusion of CuCl₂ solutions caused acute dose-dependent cardiac dysfunction in normal hearts. Several measures of baseline cardiac function were impaired in diabetic hearts, and these defects were exacerbated by low-micromolar Cu²⁺ infusion. The response to infused Cu²⁺ was augmented in diabetic hearts, which became defective at lower infusion levels and underwent complete pump failure (cardiac output = 0 ml/min) more often (P < 0.0001) at concentrations that only moderately impaired function of control hearts. To our knowledge, this is the first report describing the acute effects on cardiac function of pathophysiological elevations in coronary Cu²⁺. The effects of Cu²⁺ infusion occur within minutes in both control and diabetic hearts, which suggests that they are not due to remodelling. Heightened sensitivity to the acute effects of small elevations in Cu²⁺ could contribute substantively to impaired cardiac function in patients with diabetes and is thus identified as a new mechanism of heart disease.
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Affiliation(s)
- Carlos Chun Ho Cheung
- The School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand
| | - Choong Yee Soon
- The School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand
| | - Chia-Lin Chuang
- The School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand
| | - Anthony R J Phillips
- The School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand
| | - Shaoping Zhang
- The School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand; The Maurice Wilkins Centre for Molecular BioDiscovery, Faculty of Science, The University of Auckland, Auckland, New Zealand
| | - Garth J S Cooper
- The School of Biological Sciences, Faculty of Science, University of Auckland, Auckland, New Zealand; The Maurice Wilkins Centre for Molecular BioDiscovery, Faculty of Science, The University of Auckland, Auckland, New Zealand; Department of Pharmacology, Medical Sciences Division, University of Oxford, Oxford, UK; The Centre for Advanced Discovery and Experimental Therapeutics, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Sciences Centre, The University of Manchester, Manchester, UK; The Centre for Endocrinology and Diabetes, Institute of Human Development, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK.
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6
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Neves D. Advanced glycation end-products: a common pathway in diabetes and age-related erectile dysfunction. Free Radic Res 2013; 47 Suppl 1:49-69. [PMID: 23822116 DOI: 10.3109/10715762.2013.821701] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Reactive derivatives of non-enzymatic glucose-protein condensation reactions integrate a heterogeneous group of irreversible adducts called advanced glycation end-products (AGEs). Numerous studies have investigated the role of the AGEs in cardiovascular system; however, its contribution to erectile dysfunction (ED) that is an early manifestation of cardiovascular disease has been less intensively investigated. This review summarizes the most recent advances concerning AGEs effects in the cavernous tissue of the penis and in ED onset, particularly on diabetes and aging, conditions that not only favor AGEs formation, but also increase risk of developing ED. The specific contribution of AGE on intra- and extracellular deposition of insoluble complexes, interference in activity of endothelial nitric oxide (NO) synthase, NO bioavailability, endothelial-dependent vasodilatation, as well as molecular pathways activated by receptor of AGEs are presented. Finally, the interventional actions that prevent AGEs formation, accumulation or activity in the cavernous tissue and that include nutritional pattern modulation, nutraceuticals, exercise, therapeutic strategies (statins, anti-diabetics, inhibitors of phosphodiesterase-5, anti-hypertensive drugs) and inhibitors of AGEs formation and crosslink breakers, are discussed. From this review, we conclude that despite the experiments conducted in animal models pointing to the AGE/RAGE axis as a potential interventional target with respect to ED associated with diabetes and aging, the clinical data have been very disappointing and, until now, did not provide evidence of benefits of treatments directed to AGE inactivation.
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Affiliation(s)
- D Neves
- Department of Experimental Biology, Faculty of Medicine and IBMC of Universidade do Porto, Al. Prof Hernani Monteiro, Porto, Portugal.
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7
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Disturbance of copper homeostasis is a mechanism for homocysteine-induced vascular endothelial cell injury. PLoS One 2013; 8:e76209. [PMID: 24204604 PMCID: PMC3799909 DOI: 10.1371/journal.pone.0076209] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 08/21/2013] [Indexed: 02/05/2023] Open
Abstract
Elevation of serum homocysteine (Hcy) levels is a risk factor for cardiovascular diseases. Previous studies suggested that Hcy interferes with copper (Cu) metabolism in vascular endothelial cells. The present study was undertaken to test the hypothesis that Hcy-induced disturbance of Cu homeostasis leads to endothelial cell injury. Exposure of human umbilical vein endothelial cells (HUVECs) to concentrations of Hcy at 0.01, 0.1 or 1 mM resulted in a concentration-dependent decrease in cell viability and an increase in necrotic cell death. Pretreatment of the cells with a final concentration of 5 µM Cu in cultures prevented the effects of Hcy. Hcy decreased intracellular Cu concentrations. HPLC-ICP-MS analysis revealed that Hcy caused alterations in the distribution of intracellular Cu; more Cu was redistributed to low molecular weight fractions. ESI-Q-TOF detected the formation of Cu-Hcy complexes. Hcy also decreased the protein levels of Cu chaperone COX17, which was accompanied by a decrease in the activity of cytochrome c oxidase (CCO) and a collapse of mitochondrial membrane potential. These effects of Hcy were all preventable by Cu pretreatment. The study thus demonstrated that Hcy disturbs Cu homeostasis and limits the availability of Cu to critical molecules such as COX17 and CCO, leading to mitochondrial dysfunction and endothelial cell injury.
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Říha M, Karlíčková J, Filipský T, Macáková K, Hrdina R, Mladěnka P. Novel method for rapid copper chelation assessment confirmed low affinity of D-penicillamine for copper in comparison with trientine and 8-hydroxyquinolines. J Inorg Biochem 2013; 123:80-7. [PMID: 23563391 DOI: 10.1016/j.jinorgbio.2013.02.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 02/06/2013] [Accepted: 02/28/2013] [Indexed: 12/11/2022]
Abstract
Copper is an essential trace element involved in many physiological processes. Since disorder of copper homeostasis is observed in various pathologies, copper chelators may represent a promising therapeutic tool. This study was aimed at: 1) formation of an in vitro methodology for screening of copper chelators, and 2) detailed analysis of the interaction of copper with clinically used D-penicillamine (D-PEN), triethylenetetramine (trientine), experimentally tested 8-hydroxyquinolines, and the disodium salt of EDTA as a standard chelator. Methodology based on bathocuproinedisulfonic acid disodium salt (BCS), usable at (patho)physiologically relevant pHs (4.5-7.5), enabled assessment of both cuprous and cupric ions chelation and comparison of the relative affinities of the tested compounds for copper. In the case of potent chelators, the stoichiometry could be estimated too. Clioquinol, chloroxine and EDTA formed very stable complexes with Cu(+)/Cu(2+) at all tested pHs, while copper complexes with trientine were stable only under neutral or slightly acidic conditions. Non-substituted 8-hydroxyquinoline was a less efficient copper chelator, but still unequivocally more potent than D-PEN. Both 8-hydroxyquinoline and D-PEN chelation potencies, similarly to that of trientine, were pH-dependent and decreased with pH. Moreover, only D-PEN was able to reduce cupric ions. Conclusively, BCS assay represents a rapid, simple and precise method for copper chelation measurement. In addition, lower binding affinity of D-PEN compared with 8-hydroxyquinolines and trientine was demonstrated.
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Affiliation(s)
- Michal Říha
- Department of Pharmacology and Toxicology, Faculty of Pharmacy in Hradec Králové, Charles University in Prague, Heyrovského 1203, 500 05 Hradec Králové, Czech Republic
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9
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Medici V, Shibata NM, Kharbanda KK, LaSalle JM, Woods R, Liu S, Engelberg JA, Devaraj S, Török NJ, Jiang JX, Havel PJ, Lönnerdal B, Kim K, Halsted CH. Wilson's disease: changes in methionine metabolism and inflammation affect global DNA methylation in early liver disease. Hepatology 2013; 57:555-65. [PMID: 22945834 PMCID: PMC3566330 DOI: 10.1002/hep.26047] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Accepted: 08/14/2012] [Indexed: 12/18/2022]
Abstract
UNLABELLED Hepatic methionine metabolism may play an essential role in regulating methylation status and liver injury in Wilson's disease (WD) through the inhibition of S-adenosylhomocysteine hydrolase (SAHH) by copper (Cu) and the consequent accumulation of S-adenosylhomocysteine (SAH). We studied the transcript levels of selected genes related to liver injury, levels of SAHH, SAH, DNA methyltransferases genes (Dnmt1, Dnmt3a, Dnmt3b), and global DNA methylation in the tx-j mouse (tx-j), an animal model of WD. Findings were compared to those in control C3H mice, and in response to Cu chelation by penicillamine (PCA) and dietary supplementation of the methyl donor betaine to modulate inflammatory and methylation status. Transcript levels of selected genes related to endoplasmic reticulum stress, lipid synthesis, and fatty acid oxidation were down-regulated at baseline in tx-j mice, further down-regulated in response to PCA, and showed little to no response to betaine. Hepatic Sahh transcript and protein levels were reduced in tx-j mice with consequent increase of SAH levels. Hepatic Cu accumulation was associated with inflammation, as indicated by histopathology and elevated serum alanine aminotransferase (ALT) and liver tumor necrosis factor alpha (Tnf-α) levels. Dnmt3b was down-regulated in tx-j mice together with global DNA hypomethylation. PCA treatment of tx-j mice reduced Tnf-α and ALT levels, betaine treatment increased S-adenosylmethionine and up-regulated Dnmt3b levels, and both treatments restored global DNA methylation levels. CONCLUSION Reduced hepatic Sahh expression was associated with increased liver SAH levels in the tx-j model of WD, with consequent global DNA hypomethylation. Increased global DNA methylation was achieved by reducing inflammation by Cu chelation or by providing methyl groups. We propose that increased SAH levels and inflammation affect widespread epigenetic regulation of gene expression in WD.
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Affiliation(s)
- Valentina Medici
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of California Davis
| | - Noreene M. Shibata
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of California Davis
| | - Kusum K. Kharbanda
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska
| | - Janine M. LaSalle
- Department of Medical Microbiology and Immunology, University of California Davis
| | - Rima Woods
- Department of Medical Microbiology and Immunology, University of California Davis
| | - Sarah Liu
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of California Davis
| | | | | | - Natalie J. Török
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of California Davis
| | - Joy X. Jiang
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of California Davis
| | - Peter J. Havel
- Department of Molecular Biosciences, University of California Davis
- Department of Nutrition, University of California Davis
| | - Bo Lönnerdal
- Department of Nutrition, University of California Davis
| | - Kyoungmi Kim
- Department of Public Health Sciences, Division of Biostatistics, University of California Davis
| | - Charles H. Halsted
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, University of California Davis
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10
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Kang YJ. Copper and homocysteine in cardiovascular diseases. Pharmacol Ther 2010; 129:321-31. [PMID: 21130114 DOI: 10.1016/j.pharmthera.2010.11.004] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Accepted: 11/08/2010] [Indexed: 02/05/2023]
Abstract
High blood copper (Cu) and homocysteine (Hcy) concentrations have been independently reported as risk factors for cardiovascular diseases. When they are simultaneously measured, a concomitant increase in both parameters in association with vascular dysfunction has been observed. Cu chelator penicillamine can significantly diminish the inhibitory effect of Hcy on endothelial function, which has led to the interpretation that Cu mediates the deleterious effect of Hcy. However, Cu itself has been shown to be beneficial to the cardiovascular system. In particular, Cu promotion of angiogenesis has been well documented. Cu stimulates endothelial cell proliferation and differentiation and promotes microtubule formation in cultured saphenous veins. High levels of Hcy do not affect the process of microtubule formation, but the combination of Cu and Hcy leads to a significant inhibitory effect. Under other conditions, Cu does not affect, but Hcy inhibits, the endothelium-dependent relaxation of blood vessels and the combination of both augments the inhibition. Why does Cu produce adverse effects when it co-exists with Hcy? Cu forms complexes with Hcy and the Cu-Hcy complexes possess a deleterious potential due to their redox properties. Cu chelation can remove Cu from the Cu-Hcy complexes, but leaves behind high levels of Hcy and produces Cu deficiency. An alternative approach should focus on the reduction of Hcy, but maintenance of Cu, making detrimental Cu beneficial. A comprehensive understanding of Cu speciation and a development of selective modulation of Cu coordination to Cu-binding molecules to avoid Cu-Hcy complex formation would effectively improve the condition of cardiovascular disease.
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Affiliation(s)
- Y James Kang
- Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China.
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11
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Gur S, Kadowitz PJ, Hellstrom WJG. A critical appraisal of erectile function in animal models of diabetes mellitus. ACTA ACUST UNITED AC 2009; 32:93-114. [DOI: 10.1111/j.1365-2605.2008.00928.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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12
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Shukla N, Rossoni G, Hotston M, Sparatore A, Del Soldato P, Tazzari V, Persad R, Angelini GD, Jeremy JY. Effect of hydrogen sulphide-donating sildenafil (ACS6) on erectile function and oxidative stress in rabbit isolated corpus cavernosum and in hypertensive rats. BJU Int 2009; 103:1522-9. [PMID: 19245441 DOI: 10.1111/j.1464-410x.2009.08415.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To study the effect of the H(2)S-donating derivative of sildenafil (ACS6) compared to sildenafil citrate and sodium hydrosulphide (NaHS) on relaxation, superoxide formation and NADPH oxidase and type 5 phosphodiesterase (PDE5) expression in isolated rabbit cavernosal tissue and smooth muscle cells (CSMCs), and in vivo on indices of oxidative stress induced with buthionine sulphoximine (BSO). MATERIALS AND METHODS Relaxation was studied in an organ bath in response to carbachol and after incubation with interleukin-1beta for 12 h. CSMCs were incubated with tumour-necrosis factor-alpha or the thromboxane A(2) (TXA(2)) analogue, U46619, with or with no sildenafil citrate, ACS6 or NaHS for 16 h. Superoxide formation and the expression of p47(phox) (an active subunit of the NADPH oxidase complex) and PDE5 protein was then assessed using Western blotting. Rats were also treated with BSO (with or with no sildenafil citrate or ACS6) for 7 days; cavernosal cGMP, cAMP, glutathionine and plasma TXA(2) and 8-isoprostane F(2alpha) was measured by enzyme-linked immunosorbent assay. RESULTS ACS6 and sildenafil citrate relaxed cavernosal smooth muscle equipotently; NaHS alone had little effect at up to 100 microm. The formation of superoxide and expression of p47(phox) and PDE5 was reduced by ACS6, sildenafil citrate and NaHS (order of potency: ACS6 > sildenafil citrate > NaHS). The effects of ACS6 were blocked by inhibitors of protein kinase A (PKA) and PKG. In rats treated with BSO, both ASC6 and sildenafil citrate reduced the increased plasma levels of TXA(2) and 8-isoprostane F(2alpha) but increased cGMP, cAMP and glutathionine levels in corpus cavernosum. CONCLUSIONS By virtue of a dual action on PKA and PKG activation, ACS6 not only promotes erection, acutely, but might also have a long-term beneficial effect through inhibition of oxidative stress and downregulation of PDE5.
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Hotston M, Jeremy JY, Bloor J, Greaves NS, Persad R, Angelini G, Shukla N. Homocysteine and copper interact to promote type 5 phosphodiesterase expression in rabbit cavernosal smooth muscle cells. Asian J Androl 2009; 10:905-13. [PMID: 18097500 DOI: 10.1111/j.1745-7262.2008.00380.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
AIM To study the effects of homocysteine and copper on type 5 phosphodiesterase (PDE5) expression in cavernosal vascular smooth muscle cells (CVSMCs) and to investigate superoxide (O(2)(.-)) derived from nicotinamide adenine dinucleotide phosphate oxidase as homocysteine and copper generate O(2)(.-), and O(2)(.-) upregulates PDE5 expression. METHODS CVSMCs derived from rabbit penis were incubated with homocysteine or copper chloride with or without superoxide dismutase (SOD), catalase, sildenafil citrate, or apocynin (nicotinamide adenine dinucleotide phosphate inhibitor) for 16 h. The expression of PDE5 and of glyceraldehyde-3-phosphate dehydrogenase (internal standard) was assessed using Western blot analysis. In parallel, O(2)(.-) was measured spectrophotometrically. RESULTS CuCl(2) alone (up to 10 micromol/L) and homocysteine alone (up to 100 micromol/L) had no effect on O(2)(.-) formation in CVSMCs compared to controls. In combination, however, homocysteine and CuCl(2) markedly increased O(2)(.-) formation, an effect blocked by SOD, catalase, apocynin, and sildenafil (1 micromol/L) when co-incubated over the same time course. PDE5 expression was also significantly increased in CVSMCs incubated with homocysteine and CuCl(2), compared to controls. This effect was also negated by 16-h co-incubation with SOD, catalase, apocynin and sildenafil. CONCLUSION This represents a novel pathogenic mechanism underlying ED, and indicates that the therapeutic actions of prolonged sildenafil use are mediated in part through inhibition of this pathway.
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Affiliation(s)
- Matthew Hotston
- Department of Urology, University of Bristol, 13 Freeland Place, Bristol BS8 4NP, UK.
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Shukla N, Hotston M, Persad R, Angelini GD, Jeremy JY. The administration of folic acid improves erectile function and reduces intracavernosal oxidative stress in the diabetic rabbit. BJU Int 2008; 103:98-103. [PMID: 18778356 DOI: 10.1111/j.1464-410x.2008.07911.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To test the possibility that folic acid (FA) may be a means of treating erectile dysfunction (ED) in diabetes mellitus (DM), by studying the effect of FA administration to DM rabbits on cavernosal function and intrapenile oxidative stress. MATERIALS AND METHODS To investigate the effect of administering FA to DM rabbits on erectile function and oxidative stress the formation of superoxide (O(2)(-)), 8-isoprostane F(2 alpha) (8-IPF(2 alpha)) and prostacyclin (as 6-keto-PGF(1 alpha)) were assessed, as well as carbachol- and electrical field stimulated (EFS) relaxation and p47(phox) content (active component of NADPH oxidase complex). Non-ketotic DM was induced in New Zealand rabbits with alloxan and FA administered orally daily for 1 month. Rabbits were killed, penises excised and segments prepared. These were mounted in an organ bath and relaxation elicited with carbachol or EFS. O(2)(-) release was measured spectrophotometrically, p47(phox) expression by Western blotting and 8-IPF(2 alpha) and 6-keto-PGF(1 alpha) formation by enzyme-linked immunosorbant assay. Blood was collected for measurement of homocysteine, red blood cell (RBC) folate and glucose. RESULTS In cavernosal tissue from DM rabbits, carbachol-and EFS-induced relaxation was significantly impaired compared with the untreated controls. O(2)(-) release, p47(phox) expression and 8-IPF(2 alpha) formation were all enhanced and 6-keto-PGF(1 alpha) formation reduced compared with the controls. All these effects were reversed by FA. Plasma total homocysteine was reduced and RBC folate elevated. CONCLUSIONS The administration of FA may constitute a strategy for reducing ED in patients with DM.
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Affiliation(s)
- Nilima Shukla
- Department of Cardiac Surgery, Bristol Royal Infirmary, Bristol, UK
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Abstract
Important roles for reactive oxygen species (ROS) in physiology and pathophysiology have been increasingly recognized. Under normal conditions, ROS serve as signaling molecules in the regulation of cellular functions. However, enhanced ROS production as a result of the activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase contributes significantly to the pathogeneses of vascular diseases. Although it has become evident that increased ROS is associated with erectile dysfunction (ED), the sources of ROS in the penis remain largely unknown. In recent years, emergent evidence suggests the possible role of NADPH oxidase in inducing ED. In this review, we examine the relationship between ROS and ED in different disease models and discuss the current evidence basis for NADPH oxidase-derived ROS in ED.
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Affiliation(s)
- Liming Jin
- Department of Internal Medicine, University of California, Davis, CA 95616, USA.
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Hotston MR, Jeremy JY, Bloor J, Koupparis A, Persad R, Shukla N. Sildenafil inhibits the up-regulation of phosphodiesterase type 5 elicited with nicotine and tumour necrosis factor-alpha in cavernosal vascular smooth muscle cells: mediation by superoxide. BJU Int 2006; 99:612-8. [PMID: 17176295 DOI: 10.1111/j.1464-410x.2006.06618.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVES To determine whether there is an association between vascular phosphodiesterase type 5 (PDE-5) and NADPH oxidase (NOX) in cavernosal vascular smooth muscle cells (CVSMCs), and to study the actions of the PDE-5 inhibitor sildenafil; the pro-erectile actions of nitric oxide (NO) are reduced by PDE-5 which hydrolyses cGMP to inactive GMP, thus an up-regulation of PDE-5 and over-production of O(2)(-) derived from NOX might promote erectile dysfunction (ED). MATERIALS AND METHODS To study the effects of nicotine and tumour necrosis factor-alpha (TNF-alpha) on superoxide (O(2)(-)) production and PDE-5 expression, CVSMCs from rabbit penis were incubated with nicotine or TNF-alpha, and superoxide dismutase (SOD), catalase, sildenafil citrate, or apocynin (NADPH inhibitor) for 16 h. The expression of PDE-5 and of glyceraldehyde-3-phosphate dehydrogenase (internal standard) was assessed using Western blotting. O(2)(-) was measured spectrophotometrically. RESULTS After a 16-h incubation, both nicotine (maximal at 10 microm) and TNF-alpha (10 ng/mL) significantly increased O(2)(-) formation in CVSMCs; this effect was blocked by co-incubating with SOD, catalase, and sildenafil (1 microm). Apocynin also inhibited O(2)(-) formation when added after 16-h incubation with nicotine (10 microm) or TNF-alpha. PDE-5 expression was also significantly increased in CVSMCs incubated with nicotine and TNF-alpha. This effect was negated by 16-h co-incubation with SOD, catalase, apocynin, and sildenafil. CONCLUSIONS Nicotine and TNF-alpha up-regulate PDE-5 expression in CVSMCs through an a priori up-regulation of NOX and formation of O(2)(-). As PDE-5 hydrolyses cGMP, this effect might 'blunt' the pro-erectile actions of NO. Sildenafil inhibits O(2)(-) formation, and 'normalizes' PDE-5 expression. This represents a novel pathogenic mechanism underlying ED, and a novel mechanism of action of sildenafil.
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Jeremy JY, Jones RA, Koupparis AJ, Hotston M, Persad R, Angelini GD, Shukla N. Reactive oxygen species and erectile dysfunction: possible role of NADPH oxidase. Int J Impot Res 2006; 19:265-80. [PMID: 17053777 DOI: 10.1038/sj.ijir.3901523] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Erectile dysfunction (ED) is a widespread condition, the incidence of which is increasing globally. ED is also indicative of underlying vasculopathy and represents a predictor of more serious cardiovascular disorders. Understanding the aetiology of ED may therefore provide invaluable pointers to the pathobiology of other cardiovascular diseases (CVDs) and syndromes. It follows, too, that therapeutic interventions that are successful in treating ED may, ipso facto, be effective in treating the early stages of conditions that include atherosclerosis, angina, plaque rupture and diabetic angiopathy. One common pathological denominator in both CVD and ED is oxidative stress, that is, the overproduction of reactive oxygen species (ROS), in particular, superoxide (O(2)(*-)) and hydrogen peroxide (H(2)O(2)). In this review, therefore, we consider the aetiology and pathobiology of O(2)(*-) in promoting ED and focus on NADPH oxidase as an inducible source of O(2)(*-) and H(2)O(2). Therapeutic strategies aimed at reducing oxidative stress to improve erectile function are also discussed.
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Affiliation(s)
- J Y Jeremy
- Department of Cardiac Surgery, Bristol Heart Institute, Bristol Royal Infirmary, The University of Bristol, Bristol, UK.
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