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Vitek L, Hinds TD, Stec DE, Tiribelli C. The physiology of bilirubin: health and disease equilibrium. Trends Mol Med 2023; 29:315-328. [PMID: 36828710 PMCID: PMC10023336 DOI: 10.1016/j.molmed.2023.01.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 01/25/2023] [Accepted: 01/27/2023] [Indexed: 02/24/2023]
Abstract
Bilirubin has several physiological functions, both beneficial and harmful. In addition to reactive oxygen species-scavenging activities, bilirubin has potent immunosuppressive effects associated with long-term pathophysiological sequelae. It has been recently recognized as a hormone with endocrine actions and interconnected effects on various cellular signaling pathways. Current studies show that bilirubin also decreases adiposity and prevents metabolic and cardiovascular diseases. All in all, the physiological importance of bilirubin is only now coming to light, and strategies for increasing plasma bilirubin levels to combat chronic diseases are starting to be considered. This review discusses the beneficial effects of increasing plasma bilirubin, incorporates emerging areas of bilirubin biology, and provides key concepts to advance the field.
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Affiliation(s)
- Libor Vitek
- Fourth Department of Internal Medicine and Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, 120 00 Prague, Czech Republic
| | - Terry D Hinds
- Department of Pharmacology and Nutritional Sciences, Barnstable Brown Diabetes Center, Markey Cancer Center, University of Kentucky, Lexington, KY 40508, USA
| | - David E Stec
- Department of Physiology and Biophysics, Cardiorenal, and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS 39216, USA
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2
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Kipp ZA, Xu M, Bates EA, Lee WH, Kern PA, Hinds TD. Bilirubin Levels Are Negatively Correlated with Adiposity in Obese Men and Women, and Its Catabolized Product, Urobilin, Is Positively Associated with Insulin Resistance. Antioxidants (Basel) 2023; 12:antiox12010170. [PMID: 36671031 PMCID: PMC9854555 DOI: 10.3390/antiox12010170] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 01/03/2023] [Accepted: 01/09/2023] [Indexed: 01/12/2023] Open
Abstract
Bilirubin levels in obese humans and rodents have been shown to be lower than in their lean counterparts. Some studies have proposed that the glucuronyl UGT1A1 enzyme that clears bilirubin from the blood increases in the liver with obesity. UGT1A1 clearance of bilirubin allows more conjugated bilirubin to enter the intestine, where it is catabolized into urobilin, which can be then absorbed via the hepatic portal vein. We hypothesized that when bilirubin levels are decreased, the urobilin increases in the plasma of obese humans, as compared to lean humans. To test this, we measured plasma levels of bilirubin and urobilin, body mass index (BMI), adiposity, blood glucose and insulin, and HOMA IR in a small cohort of obese and lean men and women. We found that bilirubin levels negatively correlated with BMI and adiposity in obese men and women, as compared to their lean counterparts. Contrarily, urobilin levels were positively associated with adiposity and BMI. Only obese women were found to be insulin resistant based on significantly higher HOMA IR, as compared to lean women. The urobilin levels were positively associated with HOMA IR in both groups, but women had a stronger linear correlation. These studies indicate that plasma urobilin levels are associated with obesity and its comorbidities, such as insulin resistance.
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Affiliation(s)
- Zachary A. Kipp
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, 760 Press Avenue, Healthy Kentucky Research Building, Lexington, KY 40508, USA
| | - Mei Xu
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, 760 Press Avenue, Healthy Kentucky Research Building, Lexington, KY 40508, USA
| | - Evelyn A. Bates
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, 760 Press Avenue, Healthy Kentucky Research Building, Lexington, KY 40508, USA
| | - Wang-Hsin Lee
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, 760 Press Avenue, Healthy Kentucky Research Building, Lexington, KY 40508, USA
| | - Philip A. Kern
- Department of Internal Medicine, Division of Endocrinology, University of Kentucky, Lexington, KY 40508, USA
| | - Terry D. Hinds
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, 760 Press Avenue, Healthy Kentucky Research Building, Lexington, KY 40508, USA
- Barnstable Brown Diabetes Center, University of Kentucky, Lexington, KY 40508, USA
- Markey Cancer Center, University of Kentucky, Lexington, KY 40508, USA
- Correspondence:
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3
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Stec DE, Tiribelli C, Badmus OO, Hinds TD. Novel Function for Bilirubin as a Metabolic Signaling Molecule: Implications for Kidney Diseases. KIDNEY360 2022; 3:945-953. [PMID: 36128497 PMCID: PMC9438427 DOI: 10.34067/kid.0000062022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 03/24/2022] [Indexed: 01/30/2023]
Abstract
Bilirubin is the end product of the catabolism of heme via the heme oxygenase pathway. Heme oxygenase generates carbon monoxide (CO) and biliverdin from the breakdown of heme, and biliverdin is rapidly reduced to bilirubin by the enzyme biliverdin reductase (BVR). Bilirubin has long been thought of as a toxic product that is only relevant to health when blood levels are severely elevated, such as in clinical jaundice. The physiologic functions of bilirubin correlate with the growing body of evidence demonstrating the protective effects of serum bilirubin against cardiovascular and metabolic diseases. Although the correlative evidence suggests a protective effect of serum bilirubin against many diseases, the mechanism by which bilirubin offers protection against cardiovascular and metabolic diseases remains unanswered. We recently discovered a novel function for bilirubin as a signaling molecule capable of activating the peroxisome proliferator-activated receptor α (PPARα) transcription factor. This review summarizes the new finding of bilirubin as a signaling molecule and proposes several mechanisms by which this novel action of bilirubin may protect against cardiovascular and kidney diseases.
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Affiliation(s)
- David E. Stec
- Department of Physiology and Biophysics, Cardiorenal, and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | | | - Olufunto O. Badmus
- Department of Physiology and Biophysics, Cardiorenal, and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | - Terry D. Hinds
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky,Barnstable Brown Diabetes Center, University of Kentucky, Lexington, Kentucky,Markey Cancer Center, University of Kentucky, Lexington, Kentucky
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4
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Zisimopoulos DN, Kalaitzopoulou E, Skipitari M, Papadea P, Panagopoulos NT, Salahas G, Georgiou CD. Detection of superoxide radical in all biological systems by Thin Layer Chromatography. Arch Biochem Biophys 2021; 716:109110. [PMID: 34958749 DOI: 10.1016/j.abb.2021.109110] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 12/20/2022]
Abstract
The study presents a new method that detects O2•-, via quantification of 2-hydroxyethidium (2-ΟΗ-Ε+) as low as ∼30 fmoles by High-Performance Thin Layer Chromatography (HPTLC). The method isolates 2-ΟΗ-Ε+ after its extraction by the anionic detergent SDS (at 18-fold higher than its CMC) together with certain organic/inorganic reagents, and its HPTLC-separation from di-ethidium (di-Ε+) and ethidium (Ε+). Quantification of 2-OH-E+ is based on its ex/em maxima at 290/540 nm, and of di-E+ and E+ at 295/545 nm. The major innovations of the present method are the development of protocols for (i) efficient extraction (by SDS) and (ii) sensitive quantification (by HPTLC) for 2-OH-E+ (as well as di-E+ and E+) from most biological systems (animals, plants, cells, subcellular compartments, fluids). The method extracts 2-ΟΗ-Ε+ (by neutralizing the strong binding between its quaternary N+ and negatively charged sites on phospholipids, DNA etc) together with free HE, while protects both from biological oxidases, and also extracts/quantifies total proteins (hydrophilic and hydrophobic) for expressing O2•- levels per protein quantity. The method also uses SDS (at 80-fold lower than its CMC) to extract/remove/wash 2-ΟΗ-Ε+ from cell/organelle exterior membrane sites, for more accurate internal content quantification. The new method is applied on indicative biological systems: (1) artificially stressed (mouse organs and liver mitochondria and nuclei, ±exposed to paraquat, a known O2•- generator), and (2) physiologically stressed (cauliflower plant, exposed to light/dark).
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Affiliation(s)
- Dimitrios N Zisimopoulos
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, Patras, Greece.
| | - Electra Kalaitzopoulou
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, Patras, Greece.
| | - Marianna Skipitari
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, Patras, Greece.
| | - Polyxeni Papadea
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, Patras, Greece.
| | | | | | - Christos D Georgiou
- Section of Genetics, Cell Biology and Development, Department of Biology, University of Patras, Patras, Greece.
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5
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McClung JA, Levy L, Garcia V, Stec DE, Peterson SJ, Abraham NG. Heme-oxygenase and lipid mediators in obesity and associated cardiometabolic diseases: Therapeutic implications. Pharmacol Ther 2021; 231:107975. [PMID: 34499923 DOI: 10.1016/j.pharmthera.2021.107975] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 07/08/2021] [Accepted: 07/27/2021] [Indexed: 02/08/2023]
Abstract
Obesity-mediated metabolic syndrome remains the leading cause of death worldwide. Among many potential targets for pharmacological intervention, a promising strategy involves the heme oxygenase (HO) system, specifically its inducible form, HO-1. This review collects and updates much of the current knowledge relevant to pharmacology and clinical medicine concerning HO-1 in metabolic diseases and its effect on lipid metabolism. HO-1 has pleotropic effects that collectively reduce inflammation, while increasing vasodilation and insulin and leptin sensitivity. Recent reports indicate that HO-1 with its antioxidants via the effect of bilirubin increases formation of biologically active lipid metabolites such as epoxyeicosatrienoic acid (EET), omega-3 and other polyunsaturated fatty acids (PUFAs). Similarly, HO-1and bilirubin are potential therapeutic targets in the treatment of fat-induced liver diseases. HO-1-mediated upregulation of EET is capable not only of reversing endothelial dysfunction and hypertension, but also of reversing cardiac remodeling, a hallmark of the metabolic syndrome. This process involves browning of white fat tissue (i.e. formation of healthy adipocytes) and reduced lipotoxicity, which otherwise will be toxic to the heart. More importantly, this review examines the activity of EET in biological systems and a series of pathways that explain its mechanism of action and discusses how these might be exploited for potential therapeutic use. We also discuss the link between cardiac ectopic fat deposition and cardiac function in humans, which is similar to that described in obese mice and is regulated by HO-1-EET-PGC1α signaling, a potent negative regulator of the inflammatory adipokine NOV.
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Affiliation(s)
- John A McClung
- Department of Medicine, New York Medical College, Valhalla, NY 10595, United States of America
| | - Lior Levy
- Department of Medicine, New York Medical College, Valhalla, NY 10595, United States of America
| | - Victor Garcia
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595, United States of America
| | - David E Stec
- Department of Physiology and Biophysics, Cardiorenal and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, MS 39216, United States of America.
| | - Stephen J Peterson
- Department of Medicine, Weill Cornell Medicine, New York, NY 10065, United States of America; New York Presbyterian Brooklyn Methodist Hospital, Brooklyn, NY 11215, United States of America
| | - Nader G Abraham
- Department of Medicine, New York Medical College, Valhalla, NY 10595, United States of America; Department of Pharmacology, New York Medical College, Valhalla, NY 10595, United States of America.
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6
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Tan J, Pei G, Xu Y, Hu T, Tan L, Zhong Z, Tarun P, Tang Y, Qin W. Serum Bilirubin Is Correlated With the Progression of IgA Vasculitis With Nephritis. Front Med (Lausanne) 2021; 8:596151. [PMID: 34169080 PMCID: PMC8217633 DOI: 10.3389/fmed.2021.596151] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 05/10/2021] [Indexed: 02/05/2023] Open
Abstract
Background: Bilirubin has been identified as an endogenous antioxidant and cellular protectant. The present study was performed to clarify the potential influence of serum bilirubin on IgA vasculitis with nephritis (IgAV-N). Methods: One hundred and eighty-nine IgAV-N patients over 14 years old were enrolled. The patients were divided into two groups by the optimum cut-off value calculated by ROC curve. The composite endpoints were defined as a 60% decline in estimate glomerular filtration rate (e-GFR), end-stage renal disease (ESRD) and/or death. Kaplan-Meier (K-M) analysis and multivariate Cox analysis were carried out to determine the predictors for renal outcomes. In order to eliminate the influence of different baseline data, a 1:2 propensity score (PS) match was performed to make the results comparable and convictive. Results: The baseline data suggested that patients in low serum bilirubin group had significantly higher levels of systolic blood pressure, proteinuria, serum creatinine and crescent formation ratio and lower levels of serum albumin and hemoglobin. Renal survival analysis indicated that lower serum bilirubin levels were significantly correlated with a poorer prognosis. Multivariate Cox analysis demonstrated that the higher level of serum bilirubin was an independent protective factor for renal survival (HR, 0.172; 95% CI, 0.030-0.991; P = 0.049). After PS matching, the baseline characters of two groups had no statistical differences. Similar outcomes were demonstrated in K-M curve and the multivariate Cox analysis. Conclusion: Elevated bilirubin levels might be related to the favorable renal outcomes.
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Affiliation(s)
- Jiaxing Tan
- Division of Nephrology, Department of Medicine, West China Hospital, Sichuan University, Chengdu, China.,West China School of Medicine, Sichuan University, Chengdu, China
| | - Gaiqin Pei
- Division of Nephrology, Department of Medicine, West China Hospital, Sichuan University, Chengdu, China.,West China School of Medicine, Sichuan University, Chengdu, China
| | - Yicong Xu
- West China School of Medicine, Sichuan University, Chengdu, China
| | - Tengyue Hu
- West China School of Medicine, Sichuan University, Chengdu, China
| | - Li Tan
- Division of Nephrology, Department of Medicine, West China Hospital, Sichuan University, Chengdu, China.,West China School of Medicine, Sichuan University, Chengdu, China
| | - Zhengxia Zhong
- Division of Nephrology, Department of Medicine, West China Hospital, Sichuan University, Chengdu, China.,West China School of Medicine, Sichuan University, Chengdu, China
| | - Padamata Tarun
- West China School of Medicine, Sichuan University, Chengdu, China
| | - Yi Tang
- Division of Nephrology, Department of Medicine, West China Hospital, Sichuan University, Chengdu, China
| | - Wei Qin
- Division of Nephrology, Department of Medicine, West China Hospital, Sichuan University, Chengdu, China
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7
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Lopez-Ruiz A, Juncos LA. Bile Acids are Important Contributors of AKI Associated with Liver Disease: COMMENTARY. KIDNEY360 2021; 3:25-27. [PMID: 35378025 PMCID: PMC8967617 DOI: 10.34067/kid.0002422021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 04/16/2021] [Indexed: 01/10/2023]
Affiliation(s)
- Arnaldo Lopez-Ruiz
- Department of Critical Care Medicine, AdventHealth Orlando, Orlando, Florida
| | - Luis A. Juncos
- Department of Internal Medicine/Nephrology, Central Arkansas Veterans Healthcare System, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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8
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Martínez-Casales M, Hernanz R, Alonso MJ. Vascular and Macrophage Heme Oxygenase-1 in Hypertension: A Mini-Review. Front Physiol 2021; 12:643435. [PMID: 33716792 PMCID: PMC7952647 DOI: 10.3389/fphys.2021.643435] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 02/01/2021] [Indexed: 11/13/2022] Open
Abstract
Hypertension is one predictive factor for stroke and heart ischemic disease. Nowadays, it is considered an inflammatory disease with elevated cytokine levels, oxidative stress, and infiltration of immune cells in several organs including heart, kidney, and vessels, which contribute to the hypertension-associated cardiovascular damage. Macrophages, the most abundant immune cells in tissues, have a high degree of plasticity that is manifested by polarization in different phenotypes, with the most well-known being M1 (proinflammatory) and M2 (anti-inflammatory). In hypertension, M1 phenotype predominates, producing inflammatory cytokines and oxidative stress, and mediating many mechanisms involved in the pathogenesis of this disease. The increase in the renin-angiotensin system and sympathetic activity contributes to the macrophage mobilization and to its polarization to the pro-inflammatory phenotype. Heme oxygenase-1 (HO-1), a phase II detoxification enzyme responsible for heme catabolism, is induced by oxidative stress, among others. HO-1 has been shown to protect against oxidative and inflammatory insults in hypertension, reducing end organ damage and blood pressure, not only by its expression at the vascular level, but also by shifting macrophages toward the anti-inflammatory phenotype. The regulatory role of heme availability for the synthesis of enzymes involved in hypertension development, such as cyclooxygenase or nitric oxide synthase, seems to be responsible for many of the beneficial HO-1 effects; additionally, the antioxidant, anti-inflammatory, antiapoptotic, and antiproliferative effects of the end products of its reaction, carbon monoxide, biliverdin/bilirubin, and Fe2+, would also contribute. In this review, we analyze the role of HO-1 in hypertensive pathology, focusing on its expression in macrophages.
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Affiliation(s)
- Marta Martínez-Casales
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain
| | - Raquel Hernanz
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain.,Centro de Investigación en Red en Enfermedades Cardiovasculares (CIBER-CV), Madrid, Spain
| | - María J Alonso
- Depto. de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud, Universidad Rey Juan Carlos, Alcorcón, Spain.,Centro de Investigación en Red en Enfermedades Cardiovasculares (CIBER-CV), Madrid, Spain
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9
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Creeden JF, Gordon DM, Stec DE, Hinds TD. Bilirubin as a metabolic hormone: the physiological relevance of low levels. Am J Physiol Endocrinol Metab 2021; 320:E191-E207. [PMID: 33284088 PMCID: PMC8260361 DOI: 10.1152/ajpendo.00405.2020] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Recent research on bilirubin, a historically well-known waste product of heme catabolism, suggests an entirely new function as a metabolic hormone that drives gene transcription by nuclear receptors. Studies are now revealing that low plasma bilirubin levels, defined as "hypobilirubinemia," are a possible new pathology analogous to the other end of the spectrum of extreme hyperbilirubinemia seen in patients with jaundice and liver dysfunction. Hypobilirubinemia is most commonly seen in patients with metabolic dysfunction, which may lead to cardiovascular complications and possibly stroke. We address the clinical significance of low bilirubin levels. A better understanding of bilirubin's hormonal function may explain why hypobilirubinemia might be deleterious. We present mechanisms by which bilirubin may be protective at mildly elevated levels and research directions that could generate treatment possibilities for patients with hypobilirubinemia, such as targeting of pathways that regulate its production or turnover or the newly designed bilirubin nanoparticles. Our review here calls for a shift in the perspective of an old molecule that could benefit millions of patients with hypobilirubinemia.
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Affiliation(s)
- Justin F Creeden
- Department of Neurosciences, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
| | - Darren M Gordon
- Department of Neurosciences, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio
| | - David E Stec
- Department of Physiology & Biophysics, Cardiorenal and Metabolic Diseases Research Center, University of Mississippi Medical Center, Jackson, Mississippi
| | - Terry D Hinds
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, Kentucky
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10
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Nath KA, Grande JP, Belcher JD, Garovic VD, Croatt AJ, Hillestad ML, Barry MA, Nath MC, Regan RF, Vercellotti GM. Antithrombotic effects of heme-degrading and heme-binding proteins. Am J Physiol Heart Circ Physiol 2020; 318:H671-H681. [PMID: 32004074 DOI: 10.1152/ajpheart.00280.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In the murine venous thrombosis model induced by ligation of the inferior vena cava (IVCL), genetic deficiency of heme oxygenase-1 (HO-1) increases clot size. This study examined whether induction of HO-1 or administration of its products reduces thrombosis. Venous HO-1 upregulation by gene delivery reduced clot size, as did products of HO activity, biliverdin, and carbon monoxide. Induction of HO-1 by hemin reduced clot formation, clot size, and upregulation of plasminogen activator inhibitor-1 (PAI-1) that occurs in the IVCL model, while leaving urokinase plasminogen activator (uPA) and tissue plasminogen activator (tPA) expression unaltered. The reductive effect of hemin on clot size required HO activity. The IVCL model exhibited relatively high concentrations of heme that peaked just before maximum clot size, then declined as clot size decreased. Administration of hemin decreased heme concentration in the IVCL model. HO-2 mRNA was induced twofold in the IVCL model (vs. 40-fold HO-1 induction), but clot size was not increased in HO-2-/- mice compared with HO-2+/+ mice. Hemopexin, the major heme-binding protein, was induced in the IVCL model, and clot size was increased in hemopexin-/- mice compared with hemopexin+/+ mice. We conclude that in the IVCL model, the heme-degrading protein HO-1 and HO products inhibit thrombus formation, as does the heme-binding protein, hemopexin. The reductive effects of hemin administration require HO activity and are mediated, in part, by reducing PAI-1 upregulation in the IVCL model. We speculate that HO-1, HO, and hemopexin reduce clot size by restraining the increase in clot concentration of heme (now recognized as a procoagulant) that otherwise occurs.NEW & NOTEWORTHY This study provides conclusive evidence that two proteins, one heme-degrading and the other heme-binding, inhibit clot formation. This may serve as a new therapeutic strategy in preventing and treating venous thromboembolic disease.
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Affiliation(s)
- Karl A Nath
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Joseph P Grande
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - John D Belcher
- Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, Minnesota
| | - Vesna D Garovic
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Anthony J Croatt
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | | | - Michael A Barry
- Division of Infectious Diseases, Mayo Clinic, Rochester, Minnesota
| | - Meryl C Nath
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | - Raymond F Regan
- Department of Emergency Medicine, University of Maryland School of Medicine, Baltimore, Maryland
| | - Gregory M Vercellotti
- Division of Hematology, Oncology and Transplantation, University of Minnesota, Minneapolis, Minnesota
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11
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Tsujikawa H, Tanaka S, Hara M, Kawai Y, Matsukuma Y, Torisu K, Nakano T, Tsuruya K, Kitazono T. Association of Lower Serum Bilirubin With Loss of Residual Kidney Function in Peritoneal Dialysis Patients. Ther Apher Dial 2019; 24:202-207. [PMID: 31207066 DOI: 10.1111/1744-9987.12865] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 05/08/2019] [Accepted: 06/12/2019] [Indexed: 01/31/2023]
Abstract
Bilirubin is recognized as an endogenous antioxidant, and low serum bilirubin is reported to be associated with the progression of kidney disease. However, it is unclear whether serum bilirubin levels are associated with the loss of residual kidney function (RKF) in peritoneal dialysis (PD) patients. This study investigated the relationship between serum total bilirubin and loss of RKF. We prospectively followed 94 PD patients who started PD in our hospital between June 2006 and May 2016. Ten patients who had chronic liver disease or cirrhosis were excluded. Patients were divided into three groups based on serum total bilirubin concentration tertiles: tertile 1 (T1) < 0.3, T2 = 0.3, and T3 ≥ 0.4 mg/dL. We estimated the relationship between serum bilirubin and loss of RKF, defined as daily urine volume (<100 mL) within 3 years after starting PD, using a Cox proportional hazards model. During the 3-year observation period, 22 patients lost RKF. The incidence rate of loss of RKF increased linearly with the decrease in serum total bilirubin levels (P for trend < 0.05). After adjusting for confounding factors, low serum total bilirubin level was shown to be an independent predictor of loss of RKF (hazard ratio [HR] for every 0.1 mg/dL decrease, 1.50; 95% confidence interval [CI], 1.01-2.51; HR [95%CI] for T2 and T1 [vs. T3] 2.03 [0.65-7.88] and 3.70 [1.00-15.9]). This study suggests that low serum total bilirubin levels are associated with the loss of RKF in PD patients.
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Affiliation(s)
- Hiroaki Tsujikawa
- Department of Medicine and Clinical Science, Kyushu University, Fukuoka, Japan
| | | | - Masatoshi Hara
- Department of Medicine and Clinical Science, Kyushu University, Fukuoka, Japan
| | - Yasuhiro Kawai
- Department of Medicine and Clinical Science, Kyushu University, Fukuoka, Japan
| | - Yuta Matsukuma
- Department of Medicine and Clinical Science, Kyushu University, Fukuoka, Japan
| | - Kumiko Torisu
- Department of Medicine and Clinical Science, Kyushu University, Fukuoka, Japan.,Department of Integrated Therapy for Chronic Kidney Disease, Kyushu University, Fukuoka, Japan
| | - Toshiaki Nakano
- Department of Medicine and Clinical Science, Kyushu University, Fukuoka, Japan
| | - Kazuhiko Tsuruya
- Department of Integrated Therapy for Chronic Kidney Disease, Kyushu University, Fukuoka, Japan.,Department of Nephrology, Nara Medical University, Nara, Japan
| | - Takanari Kitazono
- Department of Medicine and Clinical Science, Kyushu University, Fukuoka, Japan
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12
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Drummond HA, Mitchell ZL, Abraham NG, Stec DE. Targeting Heme Oxygenase-1 in Cardiovascular and Kidney Disease. Antioxidants (Basel) 2019; 8:antiox8060181. [PMID: 31216709 PMCID: PMC6617021 DOI: 10.3390/antiox8060181] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 06/13/2019] [Accepted: 06/15/2019] [Indexed: 12/13/2022] Open
Abstract
Heme oxygenase (HO) plays an important role in the cardiovascular system. It is involved in many physiological and pathophysiological processes in all organs of the cardiovascular system. From the regulation of blood pressure and blood flow to the adaptive response to end-organ injury, HO plays a critical role in the ability of the cardiovascular system to respond and adapt to changes in homeostasis. There have been great advances in our understanding of the role of HO in the regulation of blood pressure and target organ injury in the last decade. Results from these studies demonstrate that targeting of the HO system could provide novel therapeutic opportunities for the treatment of several cardiovascular and renal diseases. The goal of this review is to highlight the important role of HO in the regulation of cardiovascular and renal function and protection from disease and to highlight areas in which targeting of the HO system needs to be translated to help benefit patient populations.
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Affiliation(s)
- Heather A Drummond
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MI 39216, USA.
| | - Zachary L Mitchell
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MI 39216, USA.
| | - Nader G Abraham
- Departments of Medicine and Pharmacology, New York Medical College, Vahalla, NY 10595, USA.
- Joan C. Edwards School of Medicine, Marshall University, Huntington, VA 25701, USA.
| | - David E Stec
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson, MI 39216, USA.
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13
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Affiliation(s)
- Terry D Hinds
- From the Department of Physiology and Pharmacology, University of Toledo College of Medicine, OH (T.D.H.)
| | - David E Stec
- Department of Physiology and Biophysics, Mississippi Center for Obesity Research, University of Mississippi Medical Center, Jackson (D.E.S.)
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14
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Relationship between serum bilirubin concentrations and diabetic nephropathy in Shanghai Han's patients with type 1 diabetes mellitus. BMC Nephrol 2017; 18:114. [PMID: 28363276 PMCID: PMC5376273 DOI: 10.1186/s12882-017-0531-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 03/24/2017] [Indexed: 12/16/2022] Open
Abstract
Background Recent studies highlight a negative association between total bilirubin concentrations and albuminuria in patients with type 2 diabetes mellitus. Our study evaluated the relationship between bilirubin concentrations and the prevalence of diabetic nephropathy (DN) in Chinese patients with type 1 diabetes mellitus (T1DM). Methods A total of 258 patients with T1DM were recruited and bilirubin concentrations were compared between patients with or without diabetic nephropathy. Multiple stepwise regression analysis was used to examine the relationship between bilirubin concentrations and 24 h urinary microalbumin. Binary logistic regression analysis was performed to assess independent risk factors for diabetic nephropathy. Participants were divided into four groups according to the quartile of total bilirubin concentrations (Q1, 0.20–0.60; Q2, 0.60–0.80; Q3, 0.80–1.00; Q4, 1.00–1.90 mg/dL) and the chi-square test was used to compare the prevalence of DN in patients with T1DM. Results The median bilirubin level was 0.56 (interquartile: 0.43–0.68 mg/dL) in the DN group, significantly lower than in the non-DN group (0.70 [interquartile: 0.58–0.89 mg/dL], P < 0.001). Spearman’s correlational analysis showed bilirubin concentrations were inversely correlated with 24 h urinary microalbumin (r = -0.13, P < 0.05) and multiple stepwise regression analysis showed bilirubin concentrations were independently associated with 24 h urinary microalbumin. In logistic regression analysis, bilirubin concentrations were significantly inversely associated with nephropathy. In addition, in stratified analysis, from the first to the fourth quartile group, increased bilirubin concentrations were associated with decreased prevalence of DN from 21.90% to 2.00%. Conclusion High bilirubin concentrations are independently and negatively associated with albuminuria and the prevalence of DN in patients with T1DM.
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Abstract
Heme oxygenases are composed of two isozymes, Hmox1 and Hmox2, that catalyze the degradation of heme to carbon monoxide (CO), ferrous iron, and biliverdin, the latter of which is subsequently converted to bilirubin. While initially considered to be waste products, CO and biliverdin/bilirubin have been shown over the last 20 years to modulate key cellular processes, such as inflammation, cell proliferation, and apoptosis, as well as antioxidant defense. This shift in paradigm has led to the importance of heme oxygenases and their products in cell physiology now being well accepted. The identification of the two human cases thus far of heme oxygenase deficiency and the generation of mice deficient in Hmox1 or Hmox2 have reiterated a role for these enzymes in both normal cell function and disease pathogenesis, especially in the context of cardiovascular disease. This review covers the current knowledge on the function of both Hmox1 and Hmox2 at both a cellular and tissue level in the cardiovascular system. Initially, the roles of heme oxygenases in vascular health and the regulation of processes central to vascular diseases are outlined, followed by an evaluation of the role(s) of Hmox1 and Hmox2 in various diseases such as atherosclerosis, intimal hyperplasia, myocardial infarction, and angiogenesis. Finally, the therapeutic potential of heme oxygenases and their products are examined in a cardiovascular disease context, with a focus on how the knowledge we have gained on these enzymes may be capitalized in future clinical studies.
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Affiliation(s)
- Anita Ayer
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, Australia; and Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham Veterans Administration Medical Center, Birmingham, Alabama
| | - Abolfazl Zarjou
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, Australia; and Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham Veterans Administration Medical Center, Birmingham, Alabama
| | - Anupam Agarwal
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, Australia; and Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham Veterans Administration Medical Center, Birmingham, Alabama
| | - Roland Stocker
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, Australia; and Nephrology Research and Training Center, University of Alabama at Birmingham, Birmingham Veterans Administration Medical Center, Birmingham, Alabama
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Bakrania B, Du Toit EF, Ashton KJ, Kiessling CJ, Wagner KH, Headrick JP, Bulmer AC. Hyperbilirubinemia modulates myocardial function, aortic ejection, and ischemic stress resistance in the Gunn rat. Am J Physiol Heart Circ Physiol 2014; 307:H1142-9. [DOI: 10.1152/ajpheart.00001.2014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Mildly elevated circulating unconjugated bilirubin (UCB) is associated with protection against hypertension and ischemic heart disease. We assessed whether endogenously elevated bilirubin in Gunn rats modifies cardiovascular function and resistance to ischemic insult. Hearts were assessed ex vivo (Langendorff perfusion) and in vivo (Millar catheterization and echocardiography), and left ventricular myocardial gene expression was measured via quantitative real-time PCR. Ex vivo analysis revealed reduced intrinsic contractility in the Gunn myocardium (+dP/d t: 1,976 ± 622 vs. 2,907 ± 334 mmHg/s, P < 0.01; −dP/d t: −1,435 ± 372 vs. −2,234 ± 478 mmHg/s, P < 0.01), which correlated positively with myocardial UCB concentration ( P < 0.05). In vivo analyses showed no changes in left ventricular contractile parameters and ejection (fractional shortening and ejection fraction). However, Gunn rats exhibited reductions in the rate of aortic pressure development (3,008 ± 461 vs. 4,452 ± 644 mmHg/s, P < 0.02), mean aortic velocity (439 ± 64 vs. 644 ± 62 mm/s, P < 0.01), and aortic volume time integral pressure gradient (2.32 ± 0.65 vs. 5.72 ± 0.74 mmHg, P < 0.01), in association with significant aortic dilatation (12–24% increase in aortic diameter, P < 0.05). Ex vivo Gunn hearts exhibited improved ventricular function after 35 min of ischemia and 90 min of reperfusion (63 ± 14 vs. 35 ± 12%, P < 0.01). These effects were accompanied by increased glutathione peroxidase and reduced superoxide dismutase and phospholamban gene expression in Gunn rat myocardium ( P < 0.05). These data collectively indicate that hyperbilirubinemia in Gunn rats 1) reduces intrinsic cardiac contractility, which is compensated for in vivo; 2) induces aortic dilatation, which may beneficially influence aortic ejection velocities and pressures; and 3) may improve myocardial stress resistance in association with beneficial transcriptional changes. These effects may contribute to protection from cardiovascular disease with elevated bilirubin.
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Affiliation(s)
- Bhavisha Bakrania
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Queensland, Australia
| | - Eugene F. Du Toit
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Queensland, Australia
| | - Kevin J. Ashton
- Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia; and
| | - Can J. Kiessling
- Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia; and
| | - Karl-Heinz Wagner
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Queensland, Australia
- Department of Nutritional Science, University of Vienna, Vienna, Austria
| | - John P. Headrick
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Queensland, Australia
| | - Andrew C. Bulmer
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Queensland, Australia
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17
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Affiliation(s)
- Travis D Hull
- Division of Nephrology, Department of Medicine, The University of Alabama at Birmingham, Birmingham, ALDivision of Cardiothoracic Surgery, Department of Surgery, The University of Alabama at Birmingham, Birmingham, AL
| | - Anupam Agarwal
- Division of Nephrology, Department of Medicine, The University of Alabama at Birmingham, Birmingham, ALBirmingham Veterans Administration Medical Center, Birmingham, AL
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Boon AC, Bulmer AC, Coombes JS, Fassett RG. Circulating bilirubin and defense against kidney disease and cardiovascular mortality: mechanisms contributing to protection in clinical investigations. Am J Physiol Renal Physiol 2014; 307:F123-36. [DOI: 10.1152/ajprenal.00039.2014] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Unconjugated bilirubin is an endogenous circulating antioxidant, bound to albumin, and therefore is retained in the vascular compartment. Bilirubin has well-documented neurotoxic effects in infants; however, current evidence indicates mildly elevated bilirubin is associated with protection from cardiovascular disease and all-cause mortality in adults. Recent clinical studies show mildly elevated bilirubin is associated with protection from kidney damage and dysfunction, in addition to cardiovascular events and all-cause mortality in patients undergoing hemodialysis. This is the first review to examine the clinical evidence and summarize the potential mechanisms of action that link bilirubin to protection from kidney damage, subsequent kidney failure, and dialysis-related mortality. With this understanding, it is hoped that new therapies will be developed to prevent renal dysfunction and mortality from cardiovascular disease in at-risk individuals.
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Affiliation(s)
- Ai-Ching Boon
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Australia; and
| | - Andrew C. Bulmer
- Heart Foundation Research Centre, Griffith Health Institute, Griffith University, Gold Coast, Australia; and
| | - Jeff S. Coombes
- School of Human Movement Studies, University of Queensland, St Lucia, Australia
| | - Robert G. Fassett
- School of Human Movement Studies, University of Queensland, St Lucia, Australia
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19
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Chan EC, Dusting GJ, Liu GS, Jiang F. Redox mechanisms of the beneficial effects of heme oxygenase in hypertension. J Hypertens 2014; 32:1379-86; discussion 1387. [DOI: 10.1097/hjh.0000000000000179] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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20
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Serum bilirubin may serve as a marker for increased heme oxygenase activity and inducibility in tissues--a rationale for the versatile health protection associated with elevated plasma bilirubin. Med Hypotheses 2013; 81:607-10. [PMID: 23932761 DOI: 10.1016/j.mehy.2013.07.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 07/08/2013] [Indexed: 12/17/2022]
Abstract
Unconjugated bilirubin functions intracellularly as a potent inhibitor of NADPH oxidase complexes, and albumin-bound bilirubin contributes significantly to the oxidant scavenging activity of plasma. So it is not surprising that serum levels of bilirubin have been found to correlate inversely with risk for vascular diseases and a host of other disorders. Nonetheless, recent Mendelian randomization analyses reveal that individuals who carry low expression alleles of the hepatic bilirubin conjugating enzyme UGT1A1, and hence have somewhat elevated levels of plasma bilirubin throughout life, are not at decreased risk for vascular disorders. This likely reflects the fact that, in most people, plasma levels of unconjugated, unbound bilirubin--the fraction of bilirubin capable of fluxing back into cells--are so low (near 1 nM) that they can exert only a trivial antioxidant influence on cells. In light of these findings, it is reasonable to propose that the inverse correlation of plasma bilirubin and disease risks noted in many studies often reflect the fact that elevated plasma bilirubin can serve as a marker for an increased propensity to generate bilirubin within cells. Consistent with this view, high expression alleles of the major enzymatic source of bilirubin, heme oxygenase-1 (HO-1), do associate with decreased vascular risk in the majority of studies that have addressed this issue, and increased plasma bilirubin has been reported in carriers of these alleles. Hence, the consistent reduction in vascular risk noted in people with Gilbert syndrome (traditionally defined as having serum bilirubin in excess of 20 μM) is likely attributable to an increased rate of bilirubin generation within tissues, rather than to the decreased hepatic UGT1A1 activity that characterizes this syndrome. However, there is good reason to suspect that, at some sufficiently high plasma bilirubin level--as in individuals with very intense Gilbert syndrome or in Gunn rats lacking UGT1A1 activity--the plasma bilirubin pool does indeed provide some antioxidant protection to cells. Strategies for boosting bilirubin production within cells via HO-1 induction, or for mimicking bilirubin's antioxidant activity with cyanobacterial phycobilins, may have important potential for health promotion.
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21
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Therapeutic approaches to limit hemolysis-driven endothelial dysfunction: scavenging free heme to preserve vasculature homeostasis. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:396527. [PMID: 23781294 PMCID: PMC3678425 DOI: 10.1155/2013/396527] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 04/29/2013] [Accepted: 05/14/2013] [Indexed: 12/11/2022]
Abstract
Hemolysis results in the release of hemoglobin and heme into the bloodstream and is associated with the development of several pathologic conditions of different etiology, including hemoglobinopathies, hemolytic anemias, bacterial infections, malaria, and trauma. In addition, hemolysis is associated with surgical procedures, hemodialysis, blood transfusion, and other conditions in which mechanical forces can lead to red blood cell rupture. Free plasma hemoglobin and heme are toxic for the vascular endothelium since heme iron promotes oxidative stress that causes endothelial activation responsible for vasoocclusive events and thrombus formation. Moreover, free hemoglobin scavenges nitric oxide, reducing its bioavailability, and heme favours ROS production, thus causing oxidative nitric oxide consumption. This results in the dysregulation of the endothelium vasodilator:vasoconstrictor balance, leading to severe vasoconstriction and hypertension. Thus, endothelial dysfunction and impairment of cardiovascular function represent a common feature of pathologic conditions associated with hemolysis. In this review, we discuss how hemoglobin/heme released following hemolysis may affect vascular function and summarise the therapeutic approaches available to limit hemolysis-driven endothelial dysfunction. Particular emphasis is put on recent data showing the beneficial effects obtained through the use of the plasma heme scavenger hemopexin in counteracting heme-mediated endothelial damage in mouse models of hemolytic diseases.
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Tsapenko MV, d'Uscio LV, Grande JP, Croatt AJ, Hernandez MC, Ackerman AW, Katusic ZS, Nath KA. Increased production of superoxide anion contributes to dysfunction of the arteriovenous fistula. Am J Physiol Renal Physiol 2012; 303:F1601-7. [PMID: 22993073 PMCID: PMC3532470 DOI: 10.1152/ajprenal.00449.2012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 09/17/2012] [Indexed: 11/22/2022] Open
Abstract
Vascular access dysfunction causes morbidity in hemodialysis patients. This study examined the generation and pathobiological significance of superoxide anion in a rat femoral arteriovenous fistula (AVF). One week after AVF creation, there was increased production of superoxide anion accompanied by decreased total superoxide dismutase (SOD) and Cu/Zn SOD activities and induction of the redox-sensitive gene heme oxygenase-1. Immunohistochemical studies of nitrotyrosine formation demonstrated that peroxynitrite, a product of superoxide anion and nitric oxide, was present in increased amounts in endothelial and smooth muscle cells in the AVF. Because uncoupled NOS isoforms generate superoxide anion, and NOS coupling requires tetrahydrobiopterin (BH(4)) as a cofactor, we assessed NOS uncoupling by determining the ratio of BH(4) to dihydrobiopterin (BH(2)); the BH(4)-to-BH(2) ratio was markedly attenuated in the AVF. Because Src is a vasculopathic signaling species upstream and downstream of superoxide anion, such expression was evaluated; expression of Src and phosphorylated Src was both markedly increased in the AVF. Expression of NADPH oxidase (NOX) 1, NOX2, NOX4, cyclooxygenase (COX) 1, COX2, p47(phox), and p67(phox) was all unchanged, as assessed by Western analyses, thereby suggesting that these proteins may not be involved in increased production of superoxide anion. Finally, administration of tempol, a superoxide anion scavenger, decreased neointima formation in the juxta-anastomotic venous segment and improved AVF blood flow. We conclude that the AVF exhibits increased superoxide anion generation that may reflect the combined effects of decreased scavenging by SOD and increased generation by uncoupled NOS, and that enhanced superoxide anion production promotes juxta-anastomotic stenosis and impairs AVF function.
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23
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Csongradi E, Juncos LA, Drummond HA, Vera T, Stec DE. Role of carbon monoxide in kidney function: is a little carbon monoxide good for the kidney? Curr Pharm Biotechnol 2012; 13:819-26. [PMID: 22201605 DOI: 10.2174/138920112800399284] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 08/28/2010] [Indexed: 12/13/2022]
Abstract
Carbon monoxide (CO) is an endogenously produced gas resulting from the degradation of heme by heme oxygense or from fatty acid oxidation. Heme oxygenase (HO) enzymes are constitutively expressed in the kidney (HO-2) and HO-1 is induced in the kidney in response to several physiological and pathological stimuli. While the beneficial actions of HO in the kidney have been recognized for some time, the important role of CO in mediating these effects has not been fully examined. Recent studies using CO inhalation therapy and carbon monoxide releasing molecules (CORMs) have demonstrated that increases in CO alone can be beneficial to the kidney in several forms of acute renal injury by limiting oxidative injury, decreasing cell apoptosis, and promoting cell survival pathways. Renal CO is also emerging as a major regulator of renal vascular and tubular function acting to protect the renal vasculature against excessive vasoconstriction and to promote natriuresis by limiting sodium reabsorption in tubule cells. Within this review, recent studies on the physiological actions of CO in the kidney will be explored as well as the potential therapeutic avenues that are being developed targeting CO in the kidney which may be beneficial in diseases such as acute renal failure and hypertension.
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Affiliation(s)
- Eva Csongradi
- Department of Physiology & Biophysics, Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson, MS 39216, USA
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Stec DE, Hosick PA, Granger JP. Bilirubin, renal hemodynamics, and blood pressure. Front Pharmacol 2012; 3:18. [PMID: 22347861 PMCID: PMC3278997 DOI: 10.3389/fphar.2012.00018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 02/01/2012] [Indexed: 11/28/2022] Open
Abstract
Bilirubin is generated from the breakdown of heme by heme oxygenase and the reduction of biliverdin by the enzyme biliverdin reductase. Several large population studies have reported a significant inverse correlation between plasma bilirubin levels and the incidence of cardiovascular disease. Protection from cardiovascular disease is also observed in patients with Gilbert’s syndrome which is a disease characterized by mutations in hepatic UGT1A1, the enzyme responsible for the conjugation of bilirubin into the bile. Despite the strong correlation between plasma bilirubin levels and the protection from cardiovascular disease, the mechanism by which increases in plasma bilirubin acts to protect against cardiovascular disease is unknown. Since the chronic antihypertensive actions of bilirubin are likely due to its renal actions, the effects of moderate increases in plasma bilirubin on renal hemodynamics as well as bilirubin’s potential effects on renal tubule function will be discussed in this review. Mechanisms of action as well as the potential for antihypertensive therapies targeting moderate increases in plasma bilirubin levels will also be highlighted.
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Affiliation(s)
- David E Stec
- Department of Physiology and Biophysics, Center for Excellence in Cardiovascular - Renal Research, University of Mississippi Medical Center Jackson, MS, USA
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25
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Gómez-Guzmán M, Jiménez R, Sánchez M, Zarzuelo MJ, Galindo P, Quintela AM, López-Sepúlveda R, Romero M, Tamargo J, Vargas F, Pérez-Vizcaíno F, Duarte J. Epicatechin lowers blood pressure, restores endothelial function, and decreases oxidative stress and endothelin-1 and NADPH oxidase activity in DOCA-salt hypertension. Free Radic Biol Med 2012; 52:70-9. [PMID: 22001745 DOI: 10.1016/j.freeradbiomed.2011.09.015] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Revised: 09/13/2011] [Accepted: 09/14/2011] [Indexed: 02/07/2023]
Abstract
Flavanol-rich diets have been reported to exert beneficial effects in preventing cardiovascular diseases, such as hypertension. We studied the effects of chronic treatment with epicatechin on blood pressure, endothelial function, and oxidative status in deoxycorticosterone acetate (DOCA)-salt-induced hypertension. Rats were treated for 5 weeks with (-)-epicatechin at 2 or 10 mg kg(-1)day(-1). The high dose of epicatechin prevented both the increase in systolic blood pressure and the proteinuria induced by DOCA-salt. Plasma endothelin-1 and malondialdehyde levels and urinary iso-prostaglandin F(2α) excretion were increased in animals of the DOCA-salt group and reduced by the epicatechin 10 mg kg(-1) treatment. Aortic superoxide levels were enhanced in the DOCA-salt group and abolished by both doses of epicatechin. However, only epicatechin at 10 mg kg(-1) reduced the rise in aortic nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and p47(phox) and p22(phox) gene overexpression found in DOCA-salt animals. Epicatechin increased the transcription of nuclear factor-E2-related factor-2 (Nrf2) and Nrf2 target genes in aortas from control rats. Epicatechin also improved the impaired endothelium-dependent relaxation response to acetylcholine and increased the phosphorylation of both Akt and eNOS in aortic rings. In conclusion, epicatechin prevents hypertension, proteinuria, and vascular dysfunction. Epicatechin also induced a reduction in ET-1 release, systemic and vascular oxidative stress, and inhibition of NADPH oxidase activity.
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Affiliation(s)
- Manuel Gómez-Guzmán
- Department of Pharmacology, School of Pharmacy, School of Medicine, University of Granada, Granada, Spain
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Hosick PA, Stec DE. Heme oxygenase, a novel target for the treatment of hypertension and obesity? Am J Physiol Regul Integr Comp Physiol 2011; 302:R207-14. [PMID: 22071158 DOI: 10.1152/ajpregu.00517.2011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Heme oxygenase (HO) is the rate-limiting enzyme in the metabolism of heme-releasing bioactive molecules carbon monoxide (CO), biliverdin, and iron, each with beneficial cardiovascular actions. Biliverdin is rapidly reduced to bilirubin, a potent antioxidant, by the enzyme biliverdin reductase, and iron is rapidly sequestered by ferritin in the cell. Several studies have demonstrated that HO-1 induction can attenuate the development of hypertension as well as lower blood pressure in established hypertension in both genetic and experimental models. HO-1 induction can also reduce target organ injury and can be beneficial in cardiovascular diseases, such as heart attack and stroke. Recent studies have also identified a beneficial role for HO-1 in the regulation of body weight and metabolism in diabetes and obesity. Chronic HO-1 induction lowers body weight and corrects hyperglycemia and hyperinsulinemia. Chronic HO-1 induction also modifies the phenotype of adipocytes in obesity from one of large, cytokine producing to smaller, adiponectin producing. Finally, chronic induction of HO-1 increases oxygen consumption, CO(2), and heat production and activity in obese mice. This review will discuss the current understanding of the actions of the HO system to lower blood pressure and body weight and how HO or its metabolites may be ideal candidates for the development of drugs that can both reduce blood pressure and lower body weight.
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Affiliation(s)
- Peter A Hosick
- Dept. of Physiology and Biophysics, Univ. of Mississippi Medical Center, Jackson, MS 39216, USA
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Hosick PA, Stec DE. Heme oxygenase, a novel target for the treatment of hypertension and obesity? AMERICAN JOURNAL OF PHYSIOLOGY. REGULATORY, INTEGRATIVE AND COMPARATIVE PHYSIOLOGY 2011. [PMID: 22071158 DOI: 10.1152/ajpregu.00517.20113349392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Heme oxygenase (HO) is the rate-limiting enzyme in the metabolism of heme-releasing bioactive molecules carbon monoxide (CO), biliverdin, and iron, each with beneficial cardiovascular actions. Biliverdin is rapidly reduced to bilirubin, a potent antioxidant, by the enzyme biliverdin reductase, and iron is rapidly sequestered by ferritin in the cell. Several studies have demonstrated that HO-1 induction can attenuate the development of hypertension as well as lower blood pressure in established hypertension in both genetic and experimental models. HO-1 induction can also reduce target organ injury and can be beneficial in cardiovascular diseases, such as heart attack and stroke. Recent studies have also identified a beneficial role for HO-1 in the regulation of body weight and metabolism in diabetes and obesity. Chronic HO-1 induction lowers body weight and corrects hyperglycemia and hyperinsulinemia. Chronic HO-1 induction also modifies the phenotype of adipocytes in obesity from one of large, cytokine producing to smaller, adiponectin producing. Finally, chronic induction of HO-1 increases oxygen consumption, CO(2), and heat production and activity in obese mice. This review will discuss the current understanding of the actions of the HO system to lower blood pressure and body weight and how HO or its metabolites may be ideal candidates for the development of drugs that can both reduce blood pressure and lower body weight.
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Affiliation(s)
- Peter A Hosick
- Dept. of Physiology and Biophysics, Univ. of Mississippi Medical Center, Jackson, MS 39216, USA
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28
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Durante W. Targeting heme oxygenase-1 in vascular disease. Curr Drug Targets 2011; 11:1504-16. [PMID: 20704550 DOI: 10.2174/1389450111009011504] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 03/11/2010] [Indexed: 12/13/2022]
Abstract
Heme oxygenase-1 (HO-1) metabolizes heme to generate carbon monoxide (CO), biliverdin, and iron. Biliverdin is subsequently metabolized to bilirubin by biliverdin reductase. HO-1 has recently emerged as a promising therapeutic target in the treatment of vascular disease. Pharmacological induction or gene transfer of HO-1 ameliorates vascular dysfunction in animal models of atherosclerosis, post-angioplasty restenosis, vein graft stenosis, thrombosis, myocardial infarction, and hypertension, while inhibition of HO-1 activity or gene deletion exacerbates these disorders. The vasoprotection afforded by HO-1 is largely attributable to its end products: CO and the bile pigments, biliverdin and bilirubin. These end products exert potent anti-inflammatory, antioxidant, anti-apoptotic, and anti-thrombotic actions. In addition, CO and bile pigments act to preserve vascular homeostasis at sites of arterial injury by influencing the proliferation, migration, and adhesion of vascular smooth muscle cells, endothelial cells, endothelial progenitor cells, or leukocytes. Several strategies are currently being developed to target HO-1 in vascular disease. Pharmacological induction of HO-1 by heme derivatives, dietary antioxidants, or currently available drugs, is a promising near-term approach, while HO-1 gene delivery is a long-term therapeutic goal. Direct administration of CO via inhalation or through the use of CO-releasing molecules and/or CO-sensitizing agents provides an attractive alternative approach in targeting HO-1. Furthermore, delivery of bile pigments, either alone or in combination with CO, presents another avenue for protecting against vascular disease. Since HO-1 and its products are potentially toxic, a major challenge will be to devise clinically effective therapeutic modalities that target HO-1 without causing any adverse effects.
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Affiliation(s)
- William Durante
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri 65212, USA.
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Vera T, Stec DE. Moderate hyperbilirubinemia improves renal hemodynamics in ANG II-dependent hypertension. Am J Physiol Regul Integr Comp Physiol 2010; 299:R1044-9. [PMID: 20668235 PMCID: PMC2957382 DOI: 10.1152/ajpregu.00316.2010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2010] [Accepted: 07/25/2010] [Indexed: 11/22/2022]
Abstract
We have previously demonstrated that moderate hyperbilirubinemia decreases blood pressure in ANG II-dependent hypertension through mechanisms that decrease oxidative stress and increase nitric oxide levels. Since decreases in renal hemodynamics play an important role in mediating the hypertensive actions of ANG II, the goal of the present study was to examine the effect of moderate hyperbilirubinemia on glomerular filtration rate (GFR) and renal blood flow (RBF) in a mouse model of ANG II hypertension. Mice were made moderately hyperbilirubinemic by two methods: indinavir or specific morpholino antisense oligonucleotides against UGT1A1, which is the enzyme responsible for the conjugation of bilirubin in the liver. GFR and RBF were measured in mice after implantation of an osmotic minipump delivering ANG II at a rate of 1 μg·kg(-1)·min(-1). GFR was measured by continuous infusion of I(125)-labeled iothalamate on days 5 and 6 of ANG II infusion in conscious mice. RBF was measured on day 7 of ANG II infusion in anesthetized mice. Blood levels of unconjugated bilirubin were significantly increased in mice treated with indinavir or anti-UGT1A1 (P = 0.002). ANG II decreased GFR by 33% of control (n = 9, P = 0.004), and this was normalized by moderate hyperbilirubinemia (n = 6). Next, we examined the effect of moderate hyperbilirubinemia on RBF in ANG II-infused mice. ANG II infusion significantly decreased RBF by 22% (P = 0.037) of control, and this decrease was normalized by moderate hyperbilirubinemia (n = 6). These results indicate that improvement of renal hemodynamics may be one mechanism by which moderate hyperbilirubinemia lowers blood pressure in this model.
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Affiliation(s)
- Trinity Vera
- Dept. of Physiology and Biophysics, Center for Excellence in Cardiovascular-Renal Research, University of Mississippi Medical Center, Jackson, 39216-4505, USA
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Altered expression of the natriuretic peptide system in genetically modified heme oxygenase-1 mice treated with high dietary salt. Mol Cell Biochem 2010; 346:57-67. [PMID: 20872048 DOI: 10.1007/s11010-010-0591-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Accepted: 09/08/2010] [Indexed: 12/17/2022]
Abstract
Heme oxygenase-1 (HO-1) has been well established as a cytoprotective molecule, and has been shown to exert cardioprotective effects in both hypertension and cardiac hypertrophy. However, the precise mechanism of the cardioprotective effect of HO-1 has yet to be fully elucidated. With the natriuretic peptide system (NPS) as a key player in cardiovascular homeostasis and tissue dynamics, we sought to examine the effect of high dietary salt treatment in genetic models of HO-1 expression, and assessed the expression of the NPS in the left ventricle (LV), to determine if the effects of altered HO-1 expression may be due to modified levels of the NPS. Age-matched 12-week old male HO-1 knockout (HO-1(-/-)) and HO-1 cardiomyocyte-specific transgenic overexpressing (HO-1(Tg)) mice were treated with either normal salt (NS; 0.8%) or high salt (HS; 8.0%) chow for 5 weeks. LV mRNA expression was determined using quantitative real-time PCR. ANP peptide level was measured in the LV and plasma using radioimmunoassay, and LV cyclic 3'-5' guanosine monophosphate level was measured using an enzyme immunoassay kit. HO-1(-/-) fed HS diet had significantly higher left ventricle-to-body weight ratio (LV/BW) compared to HO-1(+/+) mice fed NS diet. HO-1(-/-) mice had significantly reduced expression of the NPS compared to controls, and these mice did not exhibit a salt-induced increase in ANP expression. HS treatment had no noticeable effect on LV/BW in HO-1(Tg) mice compared to controls. HO-1(Tg) mice had significantly higher ANP and BNP expression compared to controls. There were no differences in LV cGMP levels among all genotypes and dietary treatments. HO-1 ablation resulted in significantly lower mRNA expression of the NPS, whereas HO-1 overexpression resulted in higher mRNA expression of the NPS. Both were substantiated by peptide levels as measured by RIA. These data indicate that the detrimental effect of reduced HO-1 expression and the cardioprotective effect of increased HO-1 expression may be due, in part, to altered expression of the NPS.
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Nath KA, Hernandez MC, Croatt AJ, Katusic ZS, Juncos LA. Heme oxygenase activity as a determinant of the renal hemodynamic response to low-dose ANG II. Am J Physiol Regul Integr Comp Physiol 2010; 299:R1183-91. [PMID: 20702802 DOI: 10.1152/ajpregu.00212.2010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
ANG II causes renal injury through hemodynamic and other effects, and pressor doses of ANG II induce heme oxygenase-1 (HO-1) as a protective response. The present studies examined the hemodynamic effects of more clinically relevant, lower doses of ANG II and the role of HO activity in influencing these effects. Under euvolemic conditions, ANG II increased arterial pressure and renal vascular resistance. ANG II did not induce oxidative stress, inflammation/injury-related gene expression, or proteinuria and did not alter extrarenal vascular reactivity. At these doses, ANG II failed to increase HO-1 or HO-2 mRNA expression or HO activity. Inhibiting HO activity in ANG II-treated rats by tin mesoporphyrin further increased renal vascular resistances, decreased renal blood flow, and blunted the rise in arterial pressure without inducing oxidative stress or altering expression of selected vasoactive/injury/inflammation-related genes; tin mesoporphyrin did not alter vasorelaxation of mesenteric resistor vessels. We conclude that in this model renal vasoconstriction occurs without the recognized adverse effects of ANG II on glomerular filtration rate, renal blood flow, oxidative stress, vascular reactivity, proteinuria, and injury-related gene expression; renal HO activity is essential in preserving perfusion of the ANG II-exposed kidney. These findings represent an uncommon example wherein function of a stressed organ (by ANG II), but not that of the unstressed organ, requires intact renal HO activity, even when the imposed stress neither induces HO-1 nor HO activity. These findings may be germane to conditions attended by heightened ANG II levels, ineffective renal perfusion, and susceptibility to acute kidney injury.
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Affiliation(s)
- Karl A Nath
- Division of Nephrology and Hypertension, Mayo Clinic, Guggenheim 542, 200 First St., SW, Rochester, MN 55905, USA.
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Zielonka J, Kalyanaraman B. Hydroethidine- and MitoSOX-derived red fluorescence is not a reliable indicator of intracellular superoxide formation: another inconvenient truth. Free Radic Biol Med 2010; 48:983-1001. [PMID: 20116425 PMCID: PMC3587154 DOI: 10.1016/j.freeradbiomed.2010.01.028] [Citation(s) in RCA: 383] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 01/20/2010] [Accepted: 01/21/2010] [Indexed: 12/15/2022]
Abstract
Hydroethidine (HE; or dihydroethidium) is the most popular fluorogenic probe used for detecting intracellular superoxide radical anion. The reaction between superoxide and HE generates a highly specific red fluorescent product, 2-hydroxyethidium (2-OH-E(+)). In biological systems, another red fluorescent product, ethidium, is also formed, usually at a much higher concentration than 2-OH-E(+). In this article, we review the methods to selectively detect the superoxide-specific product (2-OH-E(+)) and the factors affecting its levels in cellular and biological systems. The most important conclusion of this review is that it is nearly impossible to assess the intracellular levels of the superoxide-specific product, 2-OH-E(+), using confocal microscopy or other fluorescence-based microscopic assays and that it is essential to measure by HPLC the intracellular HE and other oxidation products of HE, in addition to 2-OH-E(+), to fully understand the origin of red fluorescence. The chemical reactivity of mitochondria-targeted hydroethidine (Mito-HE, MitoSOX red) with superoxide is similar to the reactivity of HE with superoxide, and therefore, all of the limitations attributed to the HE assay are applicable to Mito-HE (or MitoSOX) as well.
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Affiliation(s)
- Jacek Zielonka
- Department of Biophysics and Free Radical Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
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Croatt AJ, Grande JP, Hernandez MC, Ackerman AW, Katusic ZS, Nath KA. Characterization of a model of an arteriovenous fistula in the rat: the effect of L-NAME. THE AMERICAN JOURNAL OF PATHOLOGY 2010; 176:2530-41. [PMID: 20363917 DOI: 10.2353/ajpath.2010.090649] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Vascular access dysfunction contributes to the mortality of patients undergoing chronic hemodialysis. The present study analyzed the changes that evolve in a femoral arteriovenous fistula in the rat. The venous segment of this model exhibited, at 1 week, activation of pro-inflammatory transcription factors and up-regulation of pro-inflammatory, proliferative, procoagulant, and profibrotic genes; and at 4 weeks, the venous segment displayed neointimal hyperplasia, smooth muscle proliferation, and thrombus formation. These changes were accompanied by endothelial (e) nitric oxide synthase (NOS) and inducible (i) NOS up-regulation. The administration of NG-nitro-L-arginine methyl ester, an inhibitor of NOS activity, increased venous neointimal hyperplasia and pro-inflammatory gene expression (monocyte chemoattractant protein-1 and cytokine-induced neutrophil chemoattractant-1), increased systolic blood pressure, and decreased blood flow through the fistula. In another hypertensive model, the rat subtotal nephrectomy model, venous neointimal hyperplasia in the arteriovenous fistula was also exacerbated. We conclude that this arteriovenous fistula model recapitulates the salient features observed in dysfunctional, hemodialysis arteriovenous fistulas, and that venous neointimal hyperplasia is exacerbated when this model is superimposed in two different models of systemic hypertension. Since the uremic milieu contains increased amounts of asymmetric dimethylarginine, we speculate that such accumulation of this endogenous inhibitor of NOS, by virtue of its pressor or nitric oxide-depleting effects, or a combination thereof, may contribute to the limited longevity of arteriovenous fistulas used for hemodialysis.
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Affiliation(s)
- Anthony J Croatt
- Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota 55905, USA
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Lamon BD, Zhang FF, Puri N, Brodsky SV, Goligorsky MS, Nasjletti A. Dual pathways of carbon monoxide-mediated vasoregulation: modulation by redox mechanisms. Circ Res 2009; 105:775-83. [PMID: 19745167 DOI: 10.1161/circresaha.109.197434] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
RATIONALE Vascular tissues produce carbon monoxide (CO) via HO-dependent and HO-independent mechanisms; the former in tandem with biliverdin and iron and the latter as a lone product. CO has been shown to function as both a vasoconstrictor and vasodilator; however, factors that dictate the vasoregulatory phenotype of this gas are unknown. OBJECTIVE We investigated whether CO-mediated vasoconstriction is mechanistically linked to enhanced reactive oxygen species production that masks vasodilatory pathways. METHODS AND RESULTS Sprague-Dawley rat interlobar and interlobular arteries were examined in terms of superoxide (O2*-) generation and vascular reactivity in the absence and presence of antioxidants. Both authentic CO and the CO-releasing molecule (CORM)-3 constricted renal arteries and increased O2*- production in a dose-dependent manner. The antioxidants tempol, ebselen, and deferoxamine inhibited CO-induced O2*- production and converted CO from constrictor to dilator. CO-induced O2*- generation was found to involve the activity of multiple oxidases including nitric oxide synthase, NADPH oxidase, xanthine oxidase, and complex IV of the mitochondrial electron chain. Furthermore, inhibition of these enzymes converted CO from constrictor to dilator. Similarly, biliverdin and bilirubin inhibited CO-induced O2*- production and vasoconstriction, allowing for a vasodilatory response to CO to be expressed. CO-induced vasoconstriction was dependent on a non-thromboxane agonist of the thromboxane receptor, whereas vasodilatory mechanisms of CO relied on the activation of soluble guanylate cyclase and calcium-gated potassium channels. CONCLUSIONS CO-induced vasoconstriction involves the generation of reactive oxygen species, which, when negated, allows for the expression of vasodilatory pathways which are masked by the primary oxidative stress response to this gas.
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Affiliation(s)
- Brian D Lamon
- Department of Pharmacology, New York Medical College, Valhalla, NY, USA.
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Vera T, Granger JP, Stec DE. Inhibition of bilirubin metabolism induces moderate hyperbilirubinemia and attenuates ANG II-dependent hypertension in mice. Am J Physiol Regul Integr Comp Physiol 2009; 297:R738-43. [PMID: 19571206 DOI: 10.1152/ajpregu.90889.2008] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Population studies indicate that moderate hyperbilirubinemia is associated with reduced incidence of cardiovascular diseases, including hypertension. Despite this correlative evidence, no studies have directly tested the hypothesis that moderate increases in plasma bilirubin levels can attenuate the development of hypertension. This hypothesis was tested by treating mice with Indinavir, a drug that competes with bilirubin for metabolism by UDP-glucuronosyltransferase 1A1 (UGT1A1). Treatment of mice with Indinavir (500 mg x kg(-1) x day(-1), gavage) resulted in a twofold increase in plasma unconjugated bilirubin levels. Next, we determined the effect of Indinavir-induced changes in plasma bilirubin on the development of ANG II-dependent hypertension. Moderate hyperbilirubinemia was induced 3 days before the implantation of an osmotic minipump that delivered ANG II at a rate of 1 microg x kg(-1) x min(-1). ANG II infusion increased mean arterial pressure (MAP) by 20 mmHg in control mice but by only 6 mmHg in mice treated with Indinavir (n = 6). Similar to Indinavir treatment, direct infusion of bilirubin (37.2 mg x kg(-1) x day(-1) i.v.) resulted in a twofold increase in plasma bilirubin levels and also attenuated the development of ANG II-dependent hypertension. Moderate hyperbilirubinemia resulted in an increase in plasma nitrate/nitrite levels, which averaged 36 +/- 2 vs. 50 +/- 7 microM in ANG II vehicle vs. Indinavir-treated mice (n = 5). Moderate hyperbilirubinemia resulted in attenuation of vascular oxidative stress as determined by dihydroethidium staining of aortic segments. These results indicate that moderate hyperbilirubinemia prevents ANG II-dependent hypertension by a mechanism that may involve decreases in vascular oxidative stress.
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Affiliation(s)
- Trinity Vera
- Dept. of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi 39216-4505, USA.
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Condezo-Hoyos L, Abderrahim F, Conde MV, Susín C, Díaz-Gil JJ, González MC, Arribas SM. Antioxidant activity of liver growth factor, a bilirubin covalently bound to albumin. Free Radic Biol Med 2009; 46:656-62. [PMID: 19133327 DOI: 10.1016/j.freeradbiomed.2008.12.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Revised: 10/17/2008] [Accepted: 12/03/2008] [Indexed: 10/21/2022]
Abstract
We previously reported that treatment of spontaneously hypertensive rats (SHR) with liver growth factor (LGF), an albumin-bilirubin complex with a covalent bond, reduces blood pressure, improves nitric oxide (NO)-dependent vasodilatation, and exerts vascular antifibrotic actions. Because bilirubin, albumin, and albumin-bound bilirubins have antioxidant properties, we hypothesize that LGF might exert its cardiovascular actions through an antioxidant mechanism. We have tested in vitro the capacity of LGF to scavenge ABTS cation and peroxyl and hydroxyl radicals and to protect vascular NO from degradation by superoxide anion. We have also compared the antioxidant capacity of LGF with that of its molecular components albumin and bilirubin and the reference antioxidant trolox. LGF exhibited antioxidant capacity against all free radicals tested at lower concentrations than albumin, bilirubin, and trolox. LGF, bilirubin, and albumin were also able to protect endothelial NO from superoxide anion degradation in a fashion similar to that of superoxide dismutase or tiron, but at much lower concentrations. These data, together with our previous results in SHR, suggest that LGF might exert its cardiovascular regenerative actions, at least in part, through an antioxidant mechanism and that LGF could be a relevant circulating antioxidant in situations of oxidative stress.
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Zielonka J, Hardy M, Kalyanaraman B. HPLC study of oxidation products of hydroethidine in chemical and biological systems: ramifications in superoxide measurements. Free Radic Biol Med 2009; 46:329-38. [PMID: 19026738 PMCID: PMC3375818 DOI: 10.1016/j.freeradbiomed.2008.10.031] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 10/15/2008] [Accepted: 10/17/2008] [Indexed: 12/26/2022]
Abstract
Methods for the detection and quantitation of hydroethidine (HE) and its oxidation products by HPLC analysis are described. Synthetic methods for preparation of authentic standards (2-hydroxyethidium and diethidium) are provided. Potential applications of the HPLC methods to chemical and biological systems are discussed. Specific examples of chromatograms obtained using UV-Vis absorption, fluorescence, electrochemical, and mass spectrometry detectors are provided. The development of a dual electrochemical and fluorescence detection methodology and its applications are described. The HPLC-based method enables analyses of HE and its oxidation products such as ethidium and the dimeric products of HE. The ramifications of HPLC measurement of HE and its oxidation products in the detection and quantitation of 2-hydroxyethidium, the diagnostic marker product of superoxide and HE, in the intracellular milieu are discussed. Similarly, mitochondria-targeted HE conjugated to a triphenylphosphonium group (Mito-HE or Mito-SOX) also forms oxidation products (dimers of Mito-HE and Mito-E+) that can affect the detection and quantitation of 2-hydroxy-mito-ethidium, the diagnostic marker product of Mito-HE and superoxide in mitochondria.
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Affiliation(s)
- Jacek Zielonka
- Department of Biophysics and Free Radical Research Center, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Micael Hardy
- Laboratoire SREP, UMR 6517 CNRS et Universités d'Aix-Marseille 1, 2 et 3, Centre de Saint Jérôme, 13397 Marseille, France
| | - B. Kalyanaraman
- Department of Biophysics and Free Radical Research Center, Medical College of Wisconsin, Milwaukee, WI 53226
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Gross DR. Other Transgenic Animal Models Used in Cardiovascular Studies. ANIMAL MODELS IN CARDIOVASCULAR RESEARCH 2009. [PMCID: PMC7121723 DOI: 10.1007/978-0-387-95962-7_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Previous chapters have described a large number of transgenic animal models used to study specific cardiovascular syndromes. This chapter will fill in some gaps. Many of these transgenic animals were developed to study normal and/or abnormal physiological responses in other organ systems, or to study basic biochemical and molecular reactions or pathways. These models were then discovered to also have effects on the cardiovascular system, some of them unanticipated. A word of caution, particularly when highly inbred mouse strains are used to develop transgenic models - not all strains of a particular species are created equal. When cardiovascular parameters of age- and sex-matched A/J and C57BL/6J inbred mice were compared the C57BL/6J mice demonstrated eccentric physiologic ventricular hypertrophy, increased ventricular function, lower heart rates, and increased exercise endurance.1
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Cao J, Drummond G, Inoue K, Sodhi K, Li XY, Omura S. Upregulation of heme oxygenase-1 combined with increased adiponectin lowers blood pressure in diabetic spontaneously hypertensive rats through a reduction in endothelial cell dysfunction, apoptosis and oxidative stress. Int J Mol Sci 2008; 9:2388-2406. [PMID: 19330083 PMCID: PMC2635644 DOI: 10.3390/ijms9122388] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 11/22/2008] [Accepted: 11/28/2008] [Indexed: 12/12/2022] Open
Abstract
This study was designed to investigate the effect of increased levels of HO-1 on hypertension exacerbated by diabetes. Diabetic spontaneously hypertensive rat (SHR) and WKY (control) animals were treated with streptozotocin (STZ) to induce diabetes and stannous chloride (SnCl2) to upregulate HO-1. Treatment with SnCl2 not only attenuated the increase of blood pressure (p<0.01), but also increased HO-1 protein content, HO activity and plasma adiponectin levels, decreased the levels of superoxide and 3-nitrotyrosine (NT), respectively. Reduction in oxidative stress resulted in the increased expression of Bcl-2 and AKT with a concomitant reduction in circulating endothelial cells (CEC) in the peripheral blood (p<0.005) and an improvement of femoral reactivity (response to acetylcholine). Thus induction of HO-1 accompanied with increased plasma adiponectin levels in diabetic hypertensive rats alters the phenotype through a reduction in oxidative stress, thereby permitting endothelial cells to maintain an anti-apoptotic environment and the restoration of endothelial responses thus preventing hypertension.
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Affiliation(s)
- Jian Cao
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595 USA. E-Mails:
(G. D.);
(K. I.);
(K. S.);
(S. O.)
- Department of Geriatric Cardiology, Chinese PLA General Hospital, Beijing 100853 China. E-Mail:
(J. C.);
(X. L.)
- Author to whom correspondence should be addressed; E-Mail:
; Tel. +1-914-594-4805; Fax: +1-914-594-4273
| | - George Drummond
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595 USA. E-Mails:
(G. D.);
(K. I.);
(K. S.);
(S. O.)
| | - Kazuyoshi Inoue
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595 USA. E-Mails:
(G. D.);
(K. I.);
(K. S.);
(S. O.)
| | - Komal Sodhi
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595 USA. E-Mails:
(G. D.);
(K. I.);
(K. S.);
(S. O.)
| | - Xiao Ying Li
- Department of Geriatric Cardiology, Chinese PLA General Hospital, Beijing 100853 China. E-Mail:
(J. C.);
(X. L.)
| | - Shinji Omura
- Department of Pharmacology, New York Medical College, Valhalla, NY 10595 USA. E-Mails:
(G. D.);
(K. I.);
(K. S.);
(S. O.)
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Bibliography. Current world literature. Atherosclerosis: cell biology and lipoproteins. Curr Opin Lipidol 2008; 19:525-35. [PMID: 18769235 DOI: 10.1097/mol.0b013e328312bffc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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