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Xia W, Zhang M, Liu C, Wang S, Xu A, Xia Z, Pang L, Cai Y. Exploring the therapeutic potential of tetrahydrobiopterin for heart failure with preserved ejection fraction: A path forward. Life Sci 2024; 345:122594. [PMID: 38537900 DOI: 10.1016/j.lfs.2024.122594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/10/2024] [Accepted: 03/24/2024] [Indexed: 04/02/2024]
Abstract
A large number of patients are affected by classical heart failure (HF) symptomatology with preserved ejection fraction (HFpEF) and multiorgan syndrome. Due to high morbidity and mortality rate, hospitalization and mortality remain serious socioeconomic problems, while the lack of effective pharmacological or device treatment means that HFpEF presents a major unmet medical need. Evidence from clinical and basic studies demonstrates that systemic inflammation, increased oxidative stress, and impaired mitochondrial function are the common pathological mechanisms in HFpEF. Tetrahydrobiopterin (BH4), beyond being an endogenous co-factor for catalyzing the conversion of some essential biomolecules, has the capacity to prevent systemic inflammation, enhance antioxidant resistance, and modulate mitochondrial energy production. Therefore, BH4 has emerged in the last decade as a promising agent to prevent or reverse the progression of disorders such as cardiovascular disease. In this review, we cover the clinical progress and limitations of using downstream targets of nitric oxide (NO) through NO donors, soluble guanylate cyclase activators, phosphodiesterase inhibitors, and sodium-glucose co-transporter 2 inhibitors in treating cardiovascular diseases, including HFpEF. We discuss the use of BH4 in association with HFpEF, providing new evidence for its potential use as a pharmacological option for treating HFpEF.
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Affiliation(s)
- Weiyi Xia
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Miao Zhang
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong SAR, China; Shenzhen Second People's Hospital, First Affiliated Hospital of Shenzhen University, Guangdong, China
| | - Chang Liu
- Department of Anesthesiology, The First Hospital of Jilin University, Jilin, China
| | - Sheng Wang
- Department of Anesthesiology, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Aimin Xu
- State Key Laboratory of Pharmaceutical Biotechnology, The University of Hong Kong, Hong Kong SAR, China; Department of Medicine, The University of Hong Kong, Hong Kong SAR, China; Department of Pharmacology and Pharmacy, The University of Hong Kong, Hong Kong SAR, China
| | - Zhengyuan Xia
- Department of Anesthesiology, Affiliated Hospital of Guangdong Medical University, Guangdong, China
| | - Lei Pang
- Department of Anesthesiology, The First Hospital of Jilin University, Jilin, China.
| | - Yin Cai
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong SAR, China; Research Center for Chinese Medicine Innovation, The Hong Kong Polytechnic University, Hong Kong SAR, China; Research Institute for Future Food, The Hong Kong Polytechnic University, Hong Kong SAR, China.
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2
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Kishi S, Nagasu H, Kidokoro K, Kashihara N. Oxidative stress and the role of redox signalling in chronic kidney disease. Nat Rev Nephrol 2024; 20:101-119. [PMID: 37857763 DOI: 10.1038/s41581-023-00775-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2023] [Indexed: 10/21/2023]
Abstract
Chronic kidney disease (CKD) is a major public health concern, underscoring a need to identify pathogenic mechanisms and potential therapeutic targets. Reactive oxygen species (ROS) are derivatives of oxygen molecules that are generated during aerobic metabolism and are involved in a variety of cellular functions that are governed by redox conditions. Low levels of ROS are required for diverse processes, including intracellular signal transduction, metabolism, immune and hypoxic responses, and transcriptional regulation. However, excess ROS can be pathological, and contribute to the development and progression of chronic diseases. Despite evidence linking elevated levels of ROS to CKD development and progression, the use of low-molecular-weight antioxidants to remove ROS has not been successful in preventing or slowing disease progression. More recent advances have enabled evaluation of the molecular interactions between specific ROS and their targets in redox signalling pathways. Such studies may pave the way for the development of sophisticated treatments that allow the selective control of specific ROS-mediated signalling pathways.
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Affiliation(s)
- Seiji Kishi
- Department of Nephrology and Hypertension, Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Hajime Nagasu
- Department of Nephrology and Hypertension, Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Kengo Kidokoro
- Department of Nephrology and Hypertension, Kawasaki Medical School, Kurashiki, Okayama, Japan
| | - Naoki Kashihara
- Department of Nephrology and Hypertension, Kawasaki Medical School, Kurashiki, Okayama, Japan.
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3
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Shen L, Wang J, Pan Y, Huang J, Zhu K, Tu H, Chen M. Characteristics of Metabolites in the Development of Atherosclerosis in Tibetan Minipigs Determined Using Untargeted Metabolomics. Nutrients 2023; 15:4425. [PMID: 37892500 PMCID: PMC10609677 DOI: 10.3390/nu15204425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 10/14/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
BACKGROUND Atherosclerosis (AS) is a chronic progressive disease caused by lipometabolic disorder. However, the pathological characteristics and mechanism of AS have not been fully clarified. Through high-fat and high-cholesterol diet induction, Tibetan minipigs can be used as the AS model animals, as they have a very similar AS pathogenesis to humans. METHODS In this study, we built an AS model of Tibetan minipigs and identified the differential abundance metabolites in the development of AS based on untargeted metabolomics. RESULTS We found that sphingolipid metabolism and glucose oxidation were obviously higher in the AS group and phenylalanine metabolism was reduced in the AS group. Moreover, in the development of AS, gluconolactone was enriched in the late stage of AS whereas biopterin was enriched in the early stage of AS. CONCLUSIONS Our research provides novel clues to investigate the metabolic mechanism of AS from the perspective of metabolomics.
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Affiliation(s)
- Liye Shen
- Academy of Chinese Medicine & Institute of Comparative Medicine, Zhejiang Chinese Medical University, Hangzhou 310024, China; (L.S.); (Y.P.); (J.H.); (K.Z.); (H.T.)
- Key Laboratory of Systems Health Science of Zhejiang Province, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Hangzhou 310024, China;
| | - Jinlong Wang
- Key Laboratory of Systems Health Science of Zhejiang Province, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Hangzhou 310024, China;
| | - Yongming Pan
- Academy of Chinese Medicine & Institute of Comparative Medicine, Zhejiang Chinese Medical University, Hangzhou 310024, China; (L.S.); (Y.P.); (J.H.); (K.Z.); (H.T.)
| | - Junjie Huang
- Academy of Chinese Medicine & Institute of Comparative Medicine, Zhejiang Chinese Medical University, Hangzhou 310024, China; (L.S.); (Y.P.); (J.H.); (K.Z.); (H.T.)
| | - Keyan Zhu
- Academy of Chinese Medicine & Institute of Comparative Medicine, Zhejiang Chinese Medical University, Hangzhou 310024, China; (L.S.); (Y.P.); (J.H.); (K.Z.); (H.T.)
| | - Haiye Tu
- Academy of Chinese Medicine & Institute of Comparative Medicine, Zhejiang Chinese Medical University, Hangzhou 310024, China; (L.S.); (Y.P.); (J.H.); (K.Z.); (H.T.)
| | - Minli Chen
- Academy of Chinese Medicine & Institute of Comparative Medicine, Zhejiang Chinese Medical University, Hangzhou 310024, China; (L.S.); (Y.P.); (J.H.); (K.Z.); (H.T.)
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4
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Janaszak-Jasiecka A, Płoska A, Wierońska JM, Dobrucki LW, Kalinowski L. Endothelial dysfunction due to eNOS uncoupling: molecular mechanisms as potential therapeutic targets. Cell Mol Biol Lett 2023; 28:21. [PMID: 36890458 PMCID: PMC9996905 DOI: 10.1186/s11658-023-00423-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 01/19/2023] [Indexed: 03/10/2023] Open
Abstract
Nitric oxide (NO) is one of the most important molecules released by endothelial cells, and its antiatherogenic properties support cardiovascular homeostasis. Diminished NO bioavailability is a common hallmark of endothelial dysfunction underlying the pathogenesis of the cardiovascular disease. Vascular NO is synthesized by endothelial nitric oxide synthase (eNOS) from the substrate L-arginine (L-Arg), with tetrahydrobiopterin (BH4) as an essential cofactor. Cardiovascular risk factors such as diabetes, dyslipidemia, hypertension, aging, or smoking increase vascular oxidative stress that strongly affects eNOS activity and leads to eNOS uncoupling. Uncoupled eNOS produces superoxide anion (O2-) instead of NO, thus becoming a source of harmful free radicals exacerbating the oxidative stress further. eNOS uncoupling is thought to be one of the major underlying causes of endothelial dysfunction observed in the pathogenesis of vascular diseases. Here, we discuss the main mechanisms of eNOS uncoupling, including oxidative depletion of the critical eNOS cofactor BH4, deficiency of eNOS substrate L-Arg, or accumulation of its analog asymmetrical dimethylarginine (ADMA), and eNOS S-glutathionylation. Moreover, potential therapeutic approaches that prevent eNOS uncoupling by improving cofactor availability, restoration of L-Arg/ADMA ratio, or modulation of eNOS S-glutathionylation are briefly outlined.
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Affiliation(s)
- Anna Janaszak-Jasiecka
- Department of Medical Laboratory Diagnostics - Fahrenheit Biobank BBMRI.Pl, Medical University of Gdansk, 7 Debinki Street, 80-211, Gdansk, Poland
| | - Agata Płoska
- Department of Medical Laboratory Diagnostics - Fahrenheit Biobank BBMRI.Pl, Medical University of Gdansk, 7 Debinki Street, 80-211, Gdansk, Poland
| | - Joanna M Wierońska
- Department of Neurobiology, Polish Academy of Sciences, Maj Institute of Pharmacology, 12 Smętna Street, 31-343, Kraków, Poland
| | - Lawrence W Dobrucki
- Department of Medical Laboratory Diagnostics - Fahrenheit Biobank BBMRI.Pl, Medical University of Gdansk, 7 Debinki Street, 80-211, Gdansk, Poland.,Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA.,Beckman Institute for Advanced Science and Technology, 405 N Mathews Ave, MC-251, Urbana, IL, 61801, USA.,Department of Biomedical and Translational Sciences, Carle-Illinois College of Medicine, Urbana, IL, USA
| | - Leszek Kalinowski
- Department of Medical Laboratory Diagnostics - Fahrenheit Biobank BBMRI.Pl, Medical University of Gdansk, 7 Debinki Street, 80-211, Gdansk, Poland. .,BioTechMed Centre, Department of Mechanics of Materials and Structures, Gdansk University of Technology, 11/12 Gabriela Narutowicza Street, 80-233, Gdansk, Poland.
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Suvorava T, Metry S, Pick S, Kojda G. Alterations in endothelial nitric oxide synthase activity and their relevance to blood pressure. Biochem Pharmacol 2022; 205:115256. [DOI: 10.1016/j.bcp.2022.115256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/12/2022] [Accepted: 09/13/2022] [Indexed: 12/15/2022]
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Ameer OZ. Hypertension in chronic kidney disease: What lies behind the scene. Front Pharmacol 2022; 13:949260. [PMID: 36304157 PMCID: PMC9592701 DOI: 10.3389/fphar.2022.949260] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 09/26/2022] [Indexed: 12/04/2022] Open
Abstract
Hypertension is a frequent condition encountered during kidney disease development and a leading cause in its progression. Hallmark factors contributing to hypertension constitute a complexity of events that progress chronic kidney disease (CKD) into end-stage renal disease (ESRD). Multiple crosstalk mechanisms are involved in sustaining the inevitable high blood pressure (BP) state in CKD, and these play an important role in the pathogenesis of increased cardiovascular (CV) events associated with CKD. The present review discusses relevant contributory mechanisms underpinning the promotion of hypertension and their consequent eventuation to renal damage and CV disease. In particular, salt and volume expansion, sympathetic nervous system (SNS) hyperactivity, upregulated renin–angiotensin–aldosterone system (RAAS), oxidative stress, vascular remodeling, endothelial dysfunction, and a range of mediators and signaling molecules which are thought to play a role in this concert of events are emphasized. As the control of high BP via therapeutic interventions can represent the key strategy to not only reduce BP but also the CV burden in kidney disease, evidence for major strategic pathways that can alleviate the progression of hypertensive kidney disease are highlighted. This review provides a particular focus on the impact of RAAS antagonists, renal nerve denervation, baroreflex stimulation, and other modalities affecting BP in the context of CKD, to provide interesting perspectives on the management of hypertensive nephropathy and associated CV comorbidities.
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Affiliation(s)
- Omar Z. Ameer
- Department of Pharmaceutical Sciences, College of Pharmacy, Alfaisal University, Riyadh, Saudi Arabia
- Department of Biomedical Sciences, Faculty of Medicine, Macquarie University, Sydney, NSW, Australia
- *Correspondence: Omar Z. Ameer,
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Liu Z, Dong N, Hui H, Wang Y, Liu F, Xu L, Liu M, Rao Z, Yuan Z, Shang Y, Feng J, Cai Z, Li F. Endothelial cell-derived tetrahydrobiopterin prevents aortic valve calcification. Eur Heart J 2022; 43:1652-1664. [PMID: 35139535 DOI: 10.1093/eurheartj/ehac037] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 01/05/2022] [Accepted: 01/20/2022] [Indexed: 11/14/2022] Open
Abstract
AIMS Tetrahydrobiopterin (BH4) is a critical determinant of the biological function of endothelial nitric oxide synthase. The present study was to investigate the role of valvular endothelial cell (VEC)-derived BH4 in aortic valve calcification. METHODS AND RESULTS Plasma and aortic valve BH4 concentrations and the BH4:BH2 ratio were significantly lower in calcific aortic valve disease patients than in controls. There was a significant decrease of the two key enzymes of BH4 biosynthesis, guanosine 5'-triphosphate cyclohydrolase I (GCH1) and dihydrofolate reductase (DHFR), in calcified aortic valves compared with the normal ones. Endothelial cell-specific deficiency of Gch1 in Apoe-/- (Apoe-/-Gch1fl/flTie2Cre) mice showed a marked increase in transvalvular peak jet velocity, calcium deposition, runt-related transcription factor 2 (Runx2), dihydroethidium (DHE), and 3-nitrotyrosine (3-NT) levels in aortic valve leaflets compared with Apoe-/-Gch1fl/fl mice after a 24-week western diet (WD) challenge. Oxidized LDL (ox-LDL) induced osteoblastic differentiation of valvular interstitial cells (VICs) co-cultured with either si-GCH1- or si-DHFR-transfected VECs, while the effects could be abolished by BH4 supplementation. Deficiency of BH4 in VECs caused peroxynitrite formation increase and 3-NT protein increase under ox-LDL stimulation in VICs. SIN-1, the peroxynitrite generator, significantly up-regulated alkaline phosphatase (ALP) and Runx2 expression in VICs via tyrosine nitration of dynamin-related protein 1 (DRP1) at Y628. Finally, folic acid (FA) significantly attenuated aortic valve calcification in WD-fed Apoe-/- mice through increasing DHFR and salvaging BH4 biosynthesis. CONCLUSION The reduction in endothelial-dependent BH4 levels promoted peroxynitrite formation, which subsequently resulted in DRP1 tyrosine nitration and osteoblastic differentiation of VICs, thereby leading to aortic valve calcification. Supplementation of FA in diet attenuated hypercholesterolaemia-induced aortic valve calcification by salvaging BH4 bioavailability.
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Affiliation(s)
- Zongtao Liu
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Ave, Wuhan 430022, Hubei, China
| | - Nianguo Dong
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Ave, Wuhan 430022, Hubei, China
| | - Haipeng Hui
- Department of Cardiology, the Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, 28# Fuxing Road, Beijing 100853, China
| | - Yixuan Wang
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Ave, Wuhan 430022, Hubei, China
| | - Fayun Liu
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Ave, Wuhan 430022, Hubei, China
| | - Li Xu
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Ave, Wuhan 430022, Hubei, China
| | - Ming Liu
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Ave, Wuhan 430022, Hubei, China
| | - Zhenqi Rao
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Ave, Wuhan 430022, Hubei, China
| | - Zhen Yuan
- Department of Cardiology, the Second Affiliated Hospital, Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou 310009, Zhejiang, China
| | - Yuqiang Shang
- Department of Cardiovascular Surgery, Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430014, Hubei, China
| | - Jun Feng
- Department of Emergency and Intensive Care Unit, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Ave, Wuhan 430030, Hubei, China
| | - Zhejun Cai
- Department of Cardiology, the Second Affiliated Hospital, Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou 310009, Zhejiang, China
| | - Fei Li
- Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Ave, Wuhan 430022, Hubei, China
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Machin DR, Clifton HL, Wray DW, Frech TM, Donato AJ. Tetrahydrobiopterin Administration Augments Exercise-Induced Hyperemia and Endothelial Function in Patients With Systemic Sclerosis. Front Med (Lausanne) 2022; 8:791689. [PMID: 35083247 PMCID: PMC8784551 DOI: 10.3389/fmed.2021.791689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 12/08/2021] [Indexed: 11/13/2022] Open
Abstract
Systemic sclerosis (SSc) is a rare, auto-immune disease with variably progressive fibrosis of the skin and internal organs, as well as vascular dysfunction. Recently, we demonstrated a decrement in exercising skeletal muscle blood flow and endothelium-dependent vasodilation in SSc, but the mechanisms responsible for these impairments have not been investigated. Thus, we sought to determine if acute administration of tetrahydrobiopterin (BH4), an essential cofactor for endothelial nitric oxide synthase (eNOS), would improve hyperemia and brachial artery vasodilation during progressive handgrip exercise in SSc. Thirteen patients with SSc (63 ± 11 years) participated in this placebo-controlled, randomized, double-blind, crossover study. Tetrahydrobiopterin (10 mg/kg) administration resulted in a ~4-fold increase in circulating BH4 concentrations (P < 0.05). Cardiovascular variables at rest were unaffected by BH4 (P > 0.05). During handgrip exercise, BH4 administration increased brachial artery blood flow (placebo: 200 ± 87; BH4: 261 ± 115 ml/min; P < 0.05) and vascular conductance (placebo: 2.0 ± 0.8; BH4: 2.5 ± 1.0 ml/min/mmHg; P < 0.05), indicating augmented resistance artery vasodilation. Tetrahydrobiopterin administration also increased brachial artery vasodilation in response to exercise (placebo: 12 ± 6; BH4: 17 ± 7%; P < 0.05), resulting in a significant upward shift in the slope relationship between Δ brachial artery vasodilation and Δ shear rate (placebo: 0.030 ± 0.007; BH4: 0.047 ± 0.007; P < 0.05) that indicates augmented sensitivity of the brachial artery to vasodilate to the sustained elevations in shear rate during handgrip exercise. These results demonstrate the efficacy of acute BH4 administration to improve both resistance and conduit vessel endothelial function in SSc, suggesting that eNOS recoupling may be an effective strategy for improving vasodilatory capacity in this patient group.
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Affiliation(s)
- Daniel R Machin
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States.,Geriatric Research Education and Clinical Center, VA Salt Lake City, Salt Lake City, UT, United States.,Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, United States
| | - Heather L Clifton
- Geriatric Research Education and Clinical Center, VA Salt Lake City, Salt Lake City, UT, United States
| | - D Walter Wray
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States.,Geriatric Research Education and Clinical Center, VA Salt Lake City, Salt Lake City, UT, United States.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, United States
| | - Tracy M Frech
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States.,Department of Internal Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Anthony J Donato
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States.,Geriatric Research Education and Clinical Center, VA Salt Lake City, Salt Lake City, UT, United States.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, United States.,Department of Biochemistry, University of Utah, Salt Lake City, UT, United States
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Ajmal M, Ajmal A, Huang L, Zeng L. The Potential Therapeutic Role of Celastrol in Patients With Heart Failure With Preserved Ejection Fraction. Front Cardiovasc Med 2021; 8:725602. [PMID: 34490381 PMCID: PMC8418197 DOI: 10.3389/fcvm.2021.725602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 07/27/2021] [Indexed: 12/07/2022] Open
Abstract
Analysis of left ventricular systolic dysfunction remained at the centre of heart failure research for many years (also known as heart failure with reduced ejection fraction, HFrEF). Although more than 50% of all heart failure patients experience a form of heart failure characterised by preserved ejection fraction (HFpEF), the pathophysiological mechanisms leading to this form of heart failure remain not well-understood. Several evidence-based treatments for HFrEF are in routine use, but there are limited evidence-based therapies for HFpEF. The effects of these remain controversial, with current treatment options being limited to managing the associated symptoms and conditions. Accumulating evidence demonstrates that pro-inflammatory and oxidative stress pathways play key roles in the development and progression of HFpEF, such as the Unfolded Protein Response (UPR) and inducible nitric oxide synthase. Celastrol, derived from medicinal plants, is a bioactive compound with strong anti-inflammatory properties, which could deem it as fruitful in overcoming the effects of such dysregulated UPR. This literature review therefore focuses on Celastrol's anti-inflammatory and antioxidant activities, alongside its other potential therapeutic activities, and its ability to impede the pathways that are thought to be involved in the development of HFpEF, such as the JAK2/STAT pathway, to elucidate the potential therapeutic role of this bioactive compound, in the treatment of HFpEF.
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Affiliation(s)
- Maryam Ajmal
- GKT School of Medical Education, Faculty of Life Science and Medicine, King's College London, London, United Kingdom
| | - Aisha Ajmal
- St. George's Hospital Medical School, University of London, London, United Kingdom
| | - Lei Huang
- Department of Heart Center, Tianjin Third Central Hospital, Tianjin, China.,Tianjin Key Laboratory of Extracorporeal Life Support for Critical Diseases, Tianjin Third Central Hospital, Tianjin, China
| | - Lingfang Zeng
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Excellence, Faculty of Life Science and Medicine, King's College London, London, United Kingdom
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The Role of Single-Nucleotide Variants of NOS1, NOS2, and NOS3 Genes in the Comorbidity of Arterial Hypertension and Tension-Type Headache. Molecules 2021; 26:molecules26061556. [PMID: 33809023 PMCID: PMC8002043 DOI: 10.3390/molecules26061556] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 03/06/2021] [Accepted: 03/09/2021] [Indexed: 12/13/2022] Open
Abstract
Patients with tension-type headache (TTH) have an increased risk of developing arterial hypertension (AH), while hypertensive subjects do seem to have an increased risk of TTH. We searched for full-text English publications in databases using keywords and combined word searches over the past 15 years. In addition, earlier publications of historical interest were included in the review. In our review, we summed up the single nucleotide variants (SNVs) of Nitric Oxide Synthases (NOSs) genes involved in the development of essential AH and TTH. The results of studies we discussed in this review are contradictory. This might be due to different designs of the studies, small sample sizes in some of them, as well as different social and geographical characteristics. However, the contribution of genetic and environmental factors remains understudied. This makes the issue interesting for researchers, as understanding these mechanisms can contribute to a search for new approaches to pathogenetic and disease-modifying treatment of the AH and TTH phenotype. New drugs against AH and TTH can be based on inhibition of nitric oxide (NO) production, blockade of steps in the NO-cGMP pathway, or NO scavenging. Indeed, selective neuronal NOS (n-NOS) and inducible NOS (i-NOS) inhibitors are already in early clinical development.
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Roumeliotis S, Mallamaci F, Zoccali C. Endothelial Dysfunction in Chronic Kidney Disease, from Biology to Clinical Outcomes: A 2020 Update. J Clin Med 2020; 9:jcm9082359. [PMID: 32718053 PMCID: PMC7465707 DOI: 10.3390/jcm9082359] [Citation(s) in RCA: 123] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/20/2020] [Accepted: 07/21/2020] [Indexed: 02/06/2023] Open
Abstract
The vascular endothelium is a dynamic, functionally complex organ, modulating multiple biological processes, including vascular tone and permeability, inflammatory responses, thrombosis, and angiogenesis. Endothelial dysfunction is a threat to the integrity of the vascular system, and it is pivotal in the pathogenesis of atherosclerosis and cardiovascular disease. Reduced nitric oxide (NO) bioavailability is a hallmark of chronic kidney disease (CKD), with this disturbance being almost universal in patients who reach the most advanced phase of CKD, end-stage kidney disease (ESKD). Low NO bioavailability in CKD depends on several mechanisms affecting the expression and the activity of endothelial NO synthase (eNOS). Accumulation of endogenous inhibitors of eNOS, inflammation and oxidative stress, advanced glycosylation products (AGEs), bone mineral balance disorders encompassing hyperphosphatemia, high levels of the phosphaturic hormone fibroblast growth factor 23 (FGF23), and low levels of the active form of vitamin D (1,25 vitamin D) and the anti-ageing vasculoprotective factor Klotho all impinge upon NO bioavailability and are critical to endothelial dysfunction in CKD. Wide-ranging multivariate interventions are needed to counter endothelial dysfunction in CKD, an alteration triggering arterial disease and cardiovascular complications in this high-risk population.
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Affiliation(s)
- Stefanos Roumeliotis
- Division of Nephrology and Hypertension, 1st Department of Internal Medicine, School of Medicine, AHEPA Hospital, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece;
| | - Francesca Mallamaci
- CNR-IFC (National Research Council of Italy, Centre of Clinical Physiology, Clinical Epidemiology of Renal Diseases and Hypertension Unit, Reggio Cal., c/o Ospedali Riuniti, 89124 Reggio Cal, Italy;
| | - Carmine Zoccali
- CNR-IFC (National Research Council of Italy, Centre of Clinical Physiology, Clinical Epidemiology of Renal Diseases and Hypertension Unit, Reggio Cal., c/o Ospedali Riuniti, 89124 Reggio Cal, Italy;
- Correspondence: ; Tel.: +39-340-73540-62
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Ismaeel A, Papoutsi E, Miserlis D, Lavado R, Haynatzki G, Casale GP, Bohannon WT, Smith RS, Eidson JL, Brumberg R, Hayson A, Kirk JS, Castro C, Sawicki I, Konstantinou C, Brewster LP, Pipinos II, Koutakis P. The Nitric Oxide System in Peripheral Artery Disease: Connection with Oxidative Stress and Biopterins. Antioxidants (Basel) 2020; 9:E590. [PMID: 32640613 PMCID: PMC7402092 DOI: 10.3390/antiox9070590] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/15/2020] [Accepted: 07/01/2020] [Indexed: 02/06/2023] Open
Abstract
Peripheral artery disease (PAD) pathophysiology extends beyond hemodynamics to include other operating mechanisms, including endothelial dysfunction. Oxidative stress may be linked to endothelial dysfunction by reducing nitric oxide (NO) bioavailability. We aimed to investigate whether the NO system and its regulators are altered in the setting of PAD and to assess the relationship between NO bioavailability and oxidative stress. Sera from 35 patients with intermittent claudication (IC), 26 patients with critical limb ischemia (CLI), and 35 non-PAD controls were analyzed to determine levels of tetrahydrobiopterin (BH4), dihydrobiopterin (BH2), nitrate/nitrite (nitric oxides, or NOx), arginine, citrulline, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and the oxidative stress markers 8-Oxo-2'-deoxyguanosine (8-OHdG), 4-hydroxynonenal (4-HNE), advanced glycation end products (AGEs), and protein carbonyls. NOx was significantly lower in IC and CLI patients compared to controls in association with elevated oxidative stress, with the greatest NOx reductions observed in CLI. Compared with controls, IC and CLI patients had reduced BH4, elevated BH2, and a reduced BH4/BH2 ratio. SDMA, the arginine/SDMA ratio, and the arginine/ADMA ratio were significantly higher in CLI patients. The NO system and its regulators are significantly compromised in PAD. This dysregulation appears to be driven by increased oxidative stress and worsens as the disease progresses from claudication to CLI.
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Affiliation(s)
- Ahmed Ismaeel
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL 32304, USA; (A.I.); (E.P.)
| | - Evlampia Papoutsi
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL 32304, USA; (A.I.); (E.P.)
| | - Dimitrios Miserlis
- Department of Surgery, University of Texas Health Science Center San Antonio, San Antonio, TX 78229, USA;
| | - Ramon Lavado
- Department of Environmental Science, Baylor University, Waco, TX 76798, USA;
| | - Gleb Haynatzki
- Department of Biostatistics, University of Nebraska Medical Center, Omaha, NE 68198, USA;
| | - George P. Casale
- Department of Surgery, University of Nebraska Medical Center, Omaha, NE 68198, USA; (G.P.C.); (I.I.P.)
| | - William T. Bohannon
- Department of Surgery, Baylor Scott & White Medical Center, Temple, TX 76508, USA; (W.T.B.); (R.S.S.); (J.L.E.); (I.S.)
| | - Robert S. Smith
- Department of Surgery, Baylor Scott & White Medical Center, Temple, TX 76508, USA; (W.T.B.); (R.S.S.); (J.L.E.); (I.S.)
| | - Jack Leigh Eidson
- Department of Surgery, Baylor Scott & White Medical Center, Temple, TX 76508, USA; (W.T.B.); (R.S.S.); (J.L.E.); (I.S.)
| | - Robert Brumberg
- Vascular Surgery Associates, Tallahassee, FL 32308, USA; (R.B.); (A.H.)
| | - Aaron Hayson
- Vascular Surgery Associates, Tallahassee, FL 32308, USA; (R.B.); (A.H.)
| | - Jeffrey S. Kirk
- Department of Vascular Surgery, Capital Regional Medical Center, Tallahassee, FL 32308, USA; (J.S.K.); (C.C.)
| | - Carlos Castro
- Department of Vascular Surgery, Capital Regional Medical Center, Tallahassee, FL 32308, USA; (J.S.K.); (C.C.)
| | - Ian Sawicki
- Department of Surgery, Baylor Scott & White Medical Center, Temple, TX 76508, USA; (W.T.B.); (R.S.S.); (J.L.E.); (I.S.)
| | - Charalambos Konstantinou
- Department of Electrical & Computer Engineering, Florida State University, Tallahassee, FL 32310, USA;
| | - Luke P. Brewster
- Department of Surgery, Emory University School of Medicine, Atlanta, GA 30322, USA;
| | - Iraklis I. Pipinos
- Department of Surgery, University of Nebraska Medical Center, Omaha, NE 68198, USA; (G.P.C.); (I.I.P.)
- Department of Surgery and Research Service, Veterans Affairs-Western Iowa Medical Center, Omaha, NE 68105, USA
| | - Panagiotis Koutakis
- Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, FL 32304, USA; (A.I.); (E.P.)
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13
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Khosravi M, Poursaleh A, Ghasempour G, Farhad S, Najafi M. The effects of oxidative stress on the development of atherosclerosis. Biol Chem 2020; 400:711-732. [PMID: 30864421 DOI: 10.1515/hsz-2018-0397] [Citation(s) in RCA: 106] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 11/29/2018] [Indexed: 12/13/2022]
Abstract
Atherosclerosis is a cardiovascular disease (CVD) known widely world wide. Several hypothesizes are suggested to be involved in the narrowing of arteries during process of atherogenesis. The oxidative modification hypothesis is related to oxidative and anti-oxidative imbalance and is the most investigated. The aim of this study was to review the role of oxidative stress in atherosclerosis. Furthermore, it describes the roles of oxidative/anti-oxidative enzymes and compounds in the macromolecular and lipoprotein modifications and in triggering inflammatory events. The reactive oxygen (ROS) and reactive nitrogen species (RNS) are the most important endogenous sources produced by non-enzymatic and enzymatic [myeloperoxidase (MPO), nicotinamide adenine dinucleotide phosphate (NADH) oxidase and lipoxygenase (LO)] reactions that may be balanced with anti-oxidative compounds [glutathione (GSH), polyphenols and vitamins] and enzymes [glutathione peroxidase (Gpx), peroxiredoxins (Prdx), superoxide dismutase (SOD) and paraoxonase (PON)]. However, the oxidative and anti-oxidative imbalance causes the involvement of cellular proliferation and migration signaling pathways and macrophage polarization leads to the formation of atherogenic plaques. On the other hand, the immune occurrences and the changes in extra cellular matrix remodeling can develop atherosclerosis process.
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Affiliation(s)
- Mohsen Khosravi
- Biochemistry Department, Firoozabadi Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Adeleh Poursaleh
- Biochemistry Department, Firoozabadi Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Ghasem Ghasempour
- Biochemistry Department, Firoozabadi Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Shaikhnia Farhad
- Biochemistry Department, Firoozabadi Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Najafi
- Microbial Biotechnology Research Center, Biochemistry Department, Firoozabadi Hospital, Iran University of Medical Sciences, Tehran, Iran
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14
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Rajendran S, Shen X, Glawe J, Kolluru GK, Kevil CG. Nitric Oxide and Hydrogen Sulfide Regulation of Ischemic Vascular Growth and Remodeling. Compr Physiol 2019; 9:1213-1247. [PMID: 31187898 DOI: 10.1002/cphy.c180026] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Ischemic vascular remodeling occurs in response to stenosis or arterial occlusion leading to a change in blood flow and tissue perfusion. Altered blood flow elicits a cascade of molecular and cellular physiological responses leading to vascular remodeling of the macro- and micro-circulation. Although cellular mechanisms of vascular remodeling such as arteriogenesis and angiogenesis have been studied, therapeutic approaches in these areas have had limited success due to the complexity and heterogeneous constellation of molecular signaling events regulating these processes. Understanding central molecular players of vascular remodeling should lead to a deeper understanding of this response and aid in the development of novel therapeutic strategies. Hydrogen sulfide (H2 S) and nitric oxide (NO) are gaseous signaling molecules that are critically involved in regulating fundamental biochemical and molecular responses necessary for vascular growth and remodeling. This review examines how NO and H2 S regulate pathophysiological mechanisms of angiogenesis and arteriogenesis, along with important chemical and experimental considerations revealed thus far. The importance of NO and H2 S bioavailability, their synthesis enzymes and cofactors, and genetic variations associated with cardiovascular risk factors suggest that they serve as pivotal regulators of vascular remodeling responses. © 2019 American Physiological Society. Compr Physiol 9:1213-1247, 2019.
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Affiliation(s)
| | - Xinggui Shen
- Departments of Pathology, LSU Health Sciences Center, Shreveport
| | - John Glawe
- Departments of Pathology, LSU Health Sciences Center, Shreveport
| | - Gopi K Kolluru
- Departments of Pathology, LSU Health Sciences Center, Shreveport
| | - Christopher G Kevil
- Departments of Pathology, LSU Health Sciences Center, Shreveport.,Departments of Cellular Biology and Anatomy, LSU Health Sciences Center, Shreveport.,Departments of Molecular and Cellular Physiology, LSU Health Sciences Center, Shreveport
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15
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Tejero J, Shiva S, Gladwin MT. Sources of Vascular Nitric Oxide and Reactive Oxygen Species and Their Regulation. Physiol Rev 2019; 99:311-379. [PMID: 30379623 DOI: 10.1152/physrev.00036.2017] [Citation(s) in RCA: 290] [Impact Index Per Article: 58.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Nitric oxide (NO) is a small free radical with critical signaling roles in physiology and pathophysiology. The generation of sufficient NO levels to regulate the resistance of the blood vessels and hence the maintenance of adequate blood flow is critical to the healthy performance of the vasculature. A novel paradigm indicates that classical NO synthesis by dedicated NO synthases is supplemented by nitrite reduction pathways under hypoxia. At the same time, reactive oxygen species (ROS), which include superoxide and hydrogen peroxide, are produced in the vascular system for signaling purposes, as effectors of the immune response, or as byproducts of cellular metabolism. NO and ROS can be generated by distinct enzymes or by the same enzyme through alternate reduction and oxidation processes. The latter oxidoreductase systems include NO synthases, molybdopterin enzymes, and hemoglobins, which can form superoxide by reduction of molecular oxygen or NO by reduction of inorganic nitrite. Enzymatic uncoupling, changes in oxygen tension, and the concentration of coenzymes and reductants can modulate the NO/ROS production from these oxidoreductases and determine the redox balance in health and disease. The dysregulation of the mechanisms involved in the generation of NO and ROS is an important cause of cardiovascular disease and target for therapy. In this review we will present the biology of NO and ROS in the cardiovascular system, with special emphasis on their routes of formation and regulation, as well as the therapeutic challenges and opportunities for the management of NO and ROS in cardiovascular disease.
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Affiliation(s)
- Jesús Tejero
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh , Pittsburgh, Pennsylvania ; Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania ; Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, Pennsylvania ; and Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Sruti Shiva
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh , Pittsburgh, Pennsylvania ; Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania ; Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, Pennsylvania ; and Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Mark T Gladwin
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh , Pittsburgh, Pennsylvania ; Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania ; Department of Pharmacology and Chemical Biology, University of Pittsburgh , Pittsburgh, Pennsylvania ; and Department of Medicine, Center for Metabolism and Mitochondrial Medicine, University of Pittsburgh , Pittsburgh, Pennsylvania
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16
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El-Daly M, Pulakazhi Venu VK, Saifeddine M, Mihara K, Kang S, Fedak PW, Alston LA, Hirota SA, Ding H, Triggle CR, Hollenberg MD. Hyperglycaemic impairment of PAR2-mediated vasodilation: Prevention by inhibition of aortic endothelial sodium-glucose-co-Transporter-2 and minimizing oxidative stress. Vascul Pharmacol 2018; 109:56-71. [DOI: 10.1016/j.vph.2018.06.006] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 05/05/2018] [Accepted: 06/09/2018] [Indexed: 01/16/2023]
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17
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Rodriguez-Miguelez P, Gregg J, Seigler N, Bass L, Thomas J, Pollock JS, Sullivan JC, Dillard TA, Harris RA. Acute Tetrahydrobiopterin Improves Endothelial Function in Patients With COPD. Chest 2018; 154:597-606. [PMID: 29705218 DOI: 10.1016/j.chest.2018.04.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 02/27/2018] [Accepted: 04/02/2018] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Cardiovascular diseases represent a hallmark characteristic in COPD, and endothelial dysfunction has been observed in these patients. Tetrahydrobiopterin (BH4) is an essential cofactor for nitric oxide (NO) synthesis and a regulator of endothelial function. The goal of this study was to test the hypothesis that a single dose of BH4 would improve endothelial function in patients with COPD via an increase in NO bioavailability. METHODS Seventeen patients with COPD completed a randomized, double-blind, placebo (PLC)-controlled, crossover trial with an acute dose of either BH4 (Kuvan; BioMarin Pharmaceutical Inc) or PLC. Flow-mediated dilation (FMD), a bioassay of endothelial function, was completed prior to and 3 h following each treatment. Phospho- and total endothelial NO synthase (NOS3) protein was evaluated after incubating endothelial cells with plasma from the patients prior to and following treatment. Fifteen demographically matched control subjects were tested at baseline for case control comparisons. RESULTS Treatment with BH4 significantly (P ≤ .004) increased FMD, improving endothelial function in patients compared to control values (P ≥ .327). BH4 increased (P = .013) the ratio of phospho-NOS3 to total NOS3 protein. No changes in FMD (P ≥ .776) or the protein ratio (P = .536) were observed following PLC. CONCLUSIONS An acute dose of BH4 was able to improve endothelial function in patients with COPD to values similar to control subjects. The improvement in endothelial function was accompanied by an increase in NOS3 phosphorylation. BH4 may represent a potential novel therapy to improve endothelial function and reduce cardiovascular disease risk in patients with COPD. TRIAL REGISTRY ClinicalTrials.gov; No.: NCT01398943; URL: www.clinicaltrials.gov.
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Affiliation(s)
| | - Justin Gregg
- Pulmonary and Critical Care Medicine Department, Greenville Memorial Hospital, Greenville, SC
| | - Nichole Seigler
- Georgia Prevention Institute, Department of Pediatrics, Augusta University, Augusta, GA
| | - Leon Bass
- Pulmonology Department, Holston Medical Group, Kingsport, TN
| | - Jeffrey Thomas
- Georgia Prevention Institute, Department of Pediatrics, Augusta University, Augusta, GA
| | - Jennifer S Pollock
- Cardio-Renal Physiology & Medicine, University of Alabama at Birmingham, Birmingham, AL
| | | | - Thomas A Dillard
- Pulmonary and Critical Care, Department of Medicine, Augusta University, Augusta, GA
| | - Ryan A Harris
- Georgia Prevention Institute, Department of Pediatrics, Augusta University, Augusta, GA; Sport and Exercise Science Research Institute, Ulster University, Jordanstown, Northern Ireland.
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18
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Heikal L, Starr A, Hussein D, Prieto-Lloret J, Aaronson P, Dailey LA, Nandi M. l-Phenylalanine Restores Vascular Function in Spontaneously Hypertensive Rats Through Activation of the GCH1-GFRP Complex. JACC Basic Transl Sci 2018; 3:366-377. [PMID: 29963647 PMCID: PMC6018612 DOI: 10.1016/j.jacbts.2018.01.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 10/27/2017] [Accepted: 01/24/2018] [Indexed: 12/11/2022]
Abstract
Tetrahydrobiopterin is an essential cofactor for NO production. Limitation of endogenous tetrahydrobiopterin reduces NO bioavailability, enhances oxidative stress, and impairs vascular function. Orally supplemented tetrahydrobiopterin has therapeutic challenges because it is rapidly oxidized in vivo. Here, the authors demonstrate that l-phenylalanine, when administered orally, raises vascular tetrahydrobiopterin, restores NO, reduces superoxide, and enhances vascular function in spontaneously hypertensive rats. This effect is achieved by activation of a protein complex (GCH1-GFRP) involved in the biosynthesis of tetrahydrobiopterin. Activation of this protein complex by l-phenylalanine or its analogues represents a novel therapeutic target for vascular disorders underpinned by reduced NO bioavailability.
Reduced nitric oxide (NO) bioavailability correlates with impaired cardiovascular function. NO is extremely labile and has been challenging to develop as a therapeutic agent. However, NO bioavailability could be enhanced by pharmacologically targeting endogenous NO regulatory pathways. Tetrahydrobiopterin, an essential cofactor for NO production, is synthesized by GTP cyclohydrolase-1 (GCH1), which complexes with GCH1 feedback regulatory protein (GFRP). The dietary amino acid l-phenylalanine activates this complex, elevating vascular BH4. Here, the authors demonstrate that l-phenylalanine administration restores vascular function in a rodent model of hypertension, suggesting the GCH1-GFRP complex represents a rational therapeutic target for diseases underpinned by endothelial dysfunction.
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Key Words
- ACh, acetylcholine
- ANOVA, analysis of variance
- BH2, dihydrobiopterin
- BH4, tetrahydrobiopterin
- EC50, effective concentration for 50% maximal response
- EDHF, endothelium derived hyperpolarizing factor
- GCH1, GTP cyclohydrolase-1
- GFRP, GCH1 feedback regulatory protein
- L-phe, l-phenylalanine
- L-tyr, l-tyrosine
- NO, nitric oxide
- ROS, reactive oxygen species
- SHR, spontaneously hypertensive rat(s)
- WKY, Wistar Kyoto rat(s)
- cardiovascular disease
- eNOS, endothelial nitric oxide synthase
- endothelium
- l-phenylalanine
- nitric oxide
- tetrahydrobiopterin
- vascular activity
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Affiliation(s)
- Lamia Heikal
- Institute of Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Anna Starr
- Institute of Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Dania Hussein
- Institute of Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Jesus Prieto-Lloret
- Division of Asthma, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Phil Aaronson
- Division of Asthma, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Lea Ann Dailey
- Institute of Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Manasi Nandi
- Institute of Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom.,Cardiovascular Division, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
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19
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Francis BN, Salameh M, Khamisy-Farah R, Farah R. Tetrahydrobiopterin (BH 4 ): Targeting endothelial nitric oxide synthase as a potential therapy for pulmonary hypertension. Cardiovasc Ther 2018; 36. [PMID: 29151278 DOI: 10.1111/1755-5922.12312] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 10/18/2017] [Accepted: 11/11/2017] [Indexed: 12/15/2022] Open
Abstract
PURPOSE Pulmonary Hypertension (PH) is complex disease which is associated with endothelial and cardiac dysfunction. Tetrahydrobiopterin (BH4 ) regulates endothelial nitric oxide synthase (eNOS) to produce nitric oxide rather than superoxide which maintains normal endothelial and cardiac function. This study explores the therapeutic potential of BH4 in experimental PH. METHODS Monocrotaline-induced PH in rats and Hph-1 deficiency in mice were used for animal experiments. Hemodynamic measurements using pressure transducers were conducted for pulmonary and cardiac pressures, and Langendorff apparatus was used for isolated heart experiments; preventive as well as rescue treatment protocols were conducted; tissues were collected for histological and biochemical studies. RESULTS In vivo acute BH4 administration reduced pulmonary artery pressure (PAP) only in the MCT rat. In a Langendorff preparation, BH4 increased right ventricular systolic pressure (RVSP) in right ventricular hypertrophy (RVH) but not in control. In "prevention" therapy, BH4 (10 and 100 mg/kg) attenuated the development of PH in rat MCT model. eNOS protein levels in lung homogenates were maintained and cGMP levels were increased. In "rescue" therapy, BH4 (10 and 100 mg/kg) ameliorated pulmonary vascular muscularization in a dose-dependent manner. RVSP was reduced in RVH and pulmonary vascular muscularization was attenuated. BH4 at 10 mg/kg reduced RV myocyte diameter while BH4 at 100 mg/kg reversed it to control level. BH4 restored normal levels of eNOS protein and in a dose of 100 mg/kg enhanced lung tissue levels of BH4 , cGMP, and NO compared to placebo. CONCLUSION The current study provides scientific evidence for a therapeutic potential of BH4 in PH and invites further investigation.
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MESH Headings
- Animals
- Antihypertensive Agents/pharmacology
- Arterial Pressure/drug effects
- Biopterins/analogs & derivatives
- Biopterins/pharmacology
- Cyclic GMP/metabolism
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Enzyme Inhibitors/pharmacology
- GTP Cyclohydrolase/deficiency
- GTP Cyclohydrolase/genetics
- Hypertension, Pulmonary/chemically induced
- Hypertension, Pulmonary/enzymology
- Hypertension, Pulmonary/physiopathology
- Hypertension, Pulmonary/prevention & control
- Isolated Heart Preparation
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Monocrotaline
- Myocardial Contraction/drug effects
- Nitric Oxide/metabolism
- Nitric Oxide Synthase Type III/antagonists & inhibitors
- Nitric Oxide Synthase Type III/metabolism
- Rats, Sprague-Dawley
- Signal Transduction/drug effects
- Time Factors
- Ventricular Function, Right/drug effects
- Ventricular Pressure/drug effects
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Affiliation(s)
- Bahaa N Francis
- Experimental Medicine and Toxicology, Imperial College London, Hammersmith Hospital, London, UK
- Department of Internal Medicine B, Ziv Medical Center, Safad, Israel
- Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel
| | - Maram Salameh
- Pharmacy Department, Carmel Medical Center, Haifa, Israel
| | | | - Raymond Farah
- Department of Internal Medicine B, Ziv Medical Center, Safad, Israel
- Faculty of Medicine in the Galilee, Bar-Ilan University, Safed, Israel
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20
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Hess S, Baker G, Gyenes G, Tsuyuki R, Newman S, Le Melledo JM. Decreased serum L-arginine and L-citrulline levels in major depression. Psychopharmacology (Berl) 2017; 234:3241-3247. [PMID: 28803324 DOI: 10.1007/s00213-017-4712-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 08/06/2017] [Indexed: 11/26/2022]
Abstract
RATIONALE It has been suggested that endothelial dysfunction caused by a decreased endothelial production of nitric oxide (NO) may contribute to the consistently observed increased risk of developing cardiovascular disease (CVD) in physically healthy patients suffering from major depression (MD). NO is a gas synthesized from Larginine (a conditionally essential amino acid) and oxygen by endothelial nitric oxide synthase (eNOS). The end products of NO production include both NO and L-citrulline. NO is rapidly reduced to the anions nitrite and nitrate, classically referred to as NO metabolites. Their measurement has been used as a surrogate measurement for endothelial NO production. We and others have shown decreased levels of NO metabolites in the serum of MD patients. The mechanism of this decreased production of NO by the endothelium has not yet been elucidated. OBJECTIVES The purpose of this study is to assess serum levels of L-arginine and L-citrulline in patients with MD. METHODS Levels of L-arginine and L-citrulline were measured in 35 unmedicated physically healthy MD patients and 36 healthy controls (HCs). RESULTS L-arginine and L-citrulline concentrations were significantly lower in MD patients than in healthy controls (L-arginine, 73.54 + 21.53 μmol/L and 84.89 + 25.16, p = 0.04 μmol/L and L-citrulline 31.58 + 6.05 μmol/L and 35.19 + 6.85 μmol/L, p = 0.03, respectively). CONCLUSIONS The decrease in L-arginine levels in MD patients is a possible explanation for the decrease in NO metabolites in MD patients and therefore may contribute, through endothelial dysfunction, to the increased CV risk associated with MD.
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Affiliation(s)
- S Hess
- Department of Psychiatry, University of Alberta, 114th street, Edmonton, AB, T6G 2B7, Canada
| | - G Baker
- Department of Psychiatry, Neurochemical Research Unit, University of Alberta, 114th street, Edmonton, AB, T6G 2B7, Canada
| | - G Gyenes
- Department of Cardiology, University of Alberta, 114th street, Edmonton, AB, T6G 2B7, Canada
| | - R Tsuyuki
- Department of Cardiology, University of Alberta, 114th street, Edmonton, AB, T6G 2B7, Canada
| | - S Newman
- Department of Psychiatry, University of Alberta, 114th street, Edmonton, AB, T6G 2B7, Canada
| | - Jean-Michel Le Melledo
- Department of Psychiatry, University of Alberta, 114th street, Edmonton, AB, T6G 2B7, Canada.
- University of Alberta Hospital, 114th street, Edmonton, AB, T6G 2B7, Canada.
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21
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Rivera JC, Noueihed B, Madaan A, Lahaie I, Pan J, Belik J, Chemtob S. Tetrahydrobiopterin (BH4) deficiency is associated with augmented inflammation and microvascular degeneration in the retina. J Neuroinflammation 2017; 14:181. [PMID: 28874201 PMCID: PMC5586016 DOI: 10.1186/s12974-017-0955-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 08/28/2017] [Indexed: 02/07/2023] Open
Abstract
Background Tetrahydrobiopterin (BH4) is an essential cofactor in multiple metabolic processes and plays an essential role in maintaining the inflammatory and neurovascular homeostasis. In this study, we have investigated the deleterious effects of BH4 deficiency on retinal vasculature during development. Methods hph-1 mice, which display deficiency in BH4 synthesis, were used to characterize the inflammatory effects and the integrity of retinal microvasculature. BH4 levels in retinas from hph-1 and wild type (WT) mice were measured by LC-MS/MS. Retinal microvascular area and microglial cells number were quantified in hph-1 and WT mice at different ages. Retinal expression of pro-inflammatory, anti-angiogenic, and neuronal-derived factors was analyzed by qPCR. BH4 supplementation was evaluated in vitro, ex-vivo, and in vivo models. Results Our findings demonstrated that BH4 levels in the retina from hph-1 mice were significantly lower by ~ 90% at all ages analyzed compared to WT mice. Juvenile hph-1 mice showed iris atrophy, persistent fetal vasculature, significant increase in the number of microglial cells (p < 0.01), as well as a marked degeneration of the retinal microvasculature. Retinal microvascular alterations in juvenile hph-1 mice were associated with a decreased expression in Norrin (0.2-fold) and its receptor Frizzled-4 (FZD4; 0.51-fold), as well as with an augmented expression of pro-inflammatory factors such as IL-6 (3.2-fold), NRLP-3 (4.4-fold), IL-1β (8.6-fold), and the anti-angiogenic factor thrombospondin-1 (TSP-1; 17.5-fold). We found that TSP-1 derived from activated microglial cells is a factor responsible of inducing microvascular degeneration, but BH4 supplementation markedly prevented hyperoxia-induced microglial activation in vitro and microvascular injury in an ex-vivo model of microvascular angiogenesis and an in vivo model of oxygen-induced retinopathy (OIR). Conclusion Our findings reveal that BH4 is a key cofactor in regulating the expression of inflammatory and anti-angiogenic factors that play an important function in the maintenance of retinal microvasculature. Electronic supplementary material The online version of this article (10.1186/s12974-017-0955-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- José Carlos Rivera
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Center, Université de Montréal, 5415 Blvd de l'Assomption, Montréal, Québec, H1T 2M4, Canada. .,Department of Pediatrics, Ophthalmology and Pharmacology, CHU Sainte-Justine Research Center, Université de Montréal, Montréal, QC, Canada.
| | - Baraa Noueihed
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Center, Université de Montréal, 5415 Blvd de l'Assomption, Montréal, Québec, H1T 2M4, Canada
| | - Ankush Madaan
- Department of Pediatrics, Ophthalmology and Pharmacology, CHU Sainte-Justine Research Center, Université de Montréal, Montréal, QC, Canada
| | - Isabelle Lahaie
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Center, Université de Montréal, 5415 Blvd de l'Assomption, Montréal, Québec, H1T 2M4, Canada
| | - Jingyi Pan
- Departments of Pediatrics and Physiology, The Hospital For Sick Children, University of Toronto, Toronto, Canada
| | - Jaques Belik
- Departments of Pediatrics and Physiology, The Hospital For Sick Children, University of Toronto, Toronto, Canada
| | - Sylvain Chemtob
- Department of Ophthalmology, Maisonneuve-Rosemont Hospital Research Center, Université de Montréal, 5415 Blvd de l'Assomption, Montréal, Québec, H1T 2M4, Canada. .,Department of Pediatrics, Ophthalmology and Pharmacology, CHU Sainte-Justine Research Center, Université de Montréal, Montréal, QC, Canada.
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Migrino RQ, Davies HA, Truran S, Karamanova N, Franco DA, Beach TG, Serrano GE, Truong D, Nikkhah M, Madine J. Amyloidogenic medin induces endothelial dysfunction and vascular inflammation through the receptor for advanced glycation endproducts. Cardiovasc Res 2017; 113:1389-1402. [PMID: 28859297 PMCID: PMC6676393 DOI: 10.1093/cvr/cvx135] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 04/17/2017] [Accepted: 07/07/2017] [Indexed: 12/25/2022] Open
Abstract
AIMS Medin is a common amyloidogenic protein in humans that accumulates in arteries with advanced age and has been implicated in vascular degeneration. Medin's effect on endothelial function remains unknown. The aims are to assess medin's effects on human arteriole endothelial function and identify potential mechanisms underlying medin-induced vascular injury. METHODS AND RESULTS Ex vivo human adipose and leptomeningeal arterioles were exposed (1 h) to medin (0.1, 1, or 5 µM) without or with FPS-ZM1 [100 µM, receptor for advanced glycation endproducts (RAGE)-specific inhibitor] and endothelium-dependent function (acetylcholine dilator response) and endothelium-independent function (dilator response to nitric oxide donor diethylenetriamine NONOate) were compared with baseline control. Human umbilical vein endothelial cells were exposed to medin without or with FPS-ZM1 and oxidative and nitrative stress, cell viability, and pro-inflammatory signaling measures were obtained. Medin caused impaired endothelial function (vs. baseline response: -45.2 ± 5.1 and -35.8 ± 7.9% in adipose and leptomeningeal arterioles, respectively, each P < 0.05). Dilator response to NONOate was not significantly changed. Medin decreased arteriole and endothelial cell nitric oxide production, increased superoxide production, reduced endothelial cell viability, proliferation, and migration. Medin increased gene and protein expression of interleukin-6 and interleukin-8 via activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB). Medin-induced endothelial dysfunction and oxidative stress were reversed by antioxidant polyethylene glycol superoxide dismutase and by RAGE inhibitor FPS-ZM1. CONCLUSIONS Medin causes human microvascular endothelial dysfunction through oxidative and nitrative stress and promotes pro-inflammatory signaling in endothelial cells. These effects appear to be mediated via RAGE. The findings represent a potential novel mechanism of vascular injury.
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Affiliation(s)
- Raymond Q. Migrino
- Office of Research, Phoenix Veterans Affairs Health Care System, 650 E. Indian School Road, Phoenix, AZ 85022, USA
- Department of Medicine, University of Arizona College of Medicine-Phoenix, AZ, USA
| | - Hannah A. Davies
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - Seth Truran
- Office of Research, Phoenix Veterans Affairs Health Care System, 650 E. Indian School Road, Phoenix, AZ 85022, USA
| | - Nina Karamanova
- Office of Research, Phoenix Veterans Affairs Health Care System, 650 E. Indian School Road, Phoenix, AZ 85022, USA
| | - Daniel A. Franco
- Office of Research, Phoenix Veterans Affairs Health Care System, 650 E. Indian School Road, Phoenix, AZ 85022, USA
| | - Thomas G. Beach
- Department of Neuropathology, Banner Sun Health Research Institute, Sun City, AZ, USA
| | - Geidy E. Serrano
- Department of Neuropathology, Banner Sun Health Research Institute, Sun City, AZ, USA
| | - Danh Truong
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA
| | - Mehdi Nikkhah
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA
| | - Jillian Madine
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
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Vascular K ATP channels mitigate severe muscle O 2 delivery-utilization mismatch during contractions in chronic heart failure rats. Respir Physiol Neurobiol 2017; 238:33-40. [PMID: 28119150 DOI: 10.1016/j.resp.2017.01.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 01/10/2017] [Accepted: 01/18/2017] [Indexed: 12/14/2022]
Abstract
The vascular ATP-sensitive K+ (KATP) channel is a mediator of skeletal muscle microvascular oxygenation (PO2mv) during contractions in health. We tested the hypothesis that KATP channel function is preserved in chronic heart failure (CHF) and therefore its inhibition would reduce PO2mv and exacerbate the time taken to reach the PO2mv steady-state during contractions of the spinotrapezius muscle. Moreover, we hypothesized that subsequent KATP channel activation would oppose the effects of this inhibition. Muscle PO2mv (phosphorescence quenching) was measured during 180s of 1-Hz twitch contractions (∼6V) under control, glibenclamide (GLI, KATP channel antagonist; 5mg/kg) and pinacidil (PIN, KATP channel agonist; 5mg/kg) conditions in 16 male Sprague-Dawley rats with CHF induced via myocardial infarction (coronary artery ligation, left ventricular end-diastolic pressure: 18±1mmHg). GLI reduced baseline PO2mv (control: 28.3±0.9, GLI: 24.8±1.0mmHg, p<0.05), lowered mean PO2mv (average PO2mv during the overall time taken to reach the steady-state; control: 20.6±0.6, GLI: 17.6±0.3mmHg, p<0.05), and slowed the attainment of steady-state PO2mv (overall mean response time; control: 66.1±10.2, GLI: 93.6±7.8s, p<0.05). PIN opposed these effects on the baseline PO2mv, mean PO2mv and time to reach the steady-state PO2mv (p<0.05 for all vs. GLI). Inhibition of KATP channels exacerbates the transient mismatch between muscle O2 delivery and utilization in CHF rats and this effect is opposed by PIN. These data reveal that the KATP channel constitutes one of the select few well-preserved mechanisms of skeletal muscle microvascular oxygenation control in CHF.
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Dikalova A, Aschner JL, Kaplowitz MR, Summar M, Fike CD. Tetrahydrobiopterin oral therapy recouples eNOS and ameliorates chronic hypoxia-induced pulmonary hypertension in newborn pigs. Am J Physiol Lung Cell Mol Physiol 2016; 311:L743-L753. [PMID: 27542807 PMCID: PMC5142125 DOI: 10.1152/ajplung.00238.2016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 08/14/2016] [Indexed: 01/21/2023] Open
Abstract
We previously showed that newborn piglets who develop pulmonary hypertension during exposure to chronic hypoxia have diminished pulmonary vascular nitric oxide (NO) production and evidence of endothelial NO synthase (eNOS) uncoupling (Fike CD, Dikalova A, Kaplowitz MR, Cunningham G, Summar M, Aschner JL. Am J Respir Cell Mol Biol 53: 255-264, 2015). Tetrahydrobiopterin (BH4) is a cofactor that promotes eNOS coupling. Current clinical strategies typically invoke initiating treatment after the diagnosis of pulmonary hypertension, rather than prophylactically. The major purpose of this study was to determine whether starting treatment with an oral BH4 compound, sapropterin dihydrochloride (sapropterin), after the onset of pulmonary hypertension would recouple eNOS in the pulmonary vasculature and ameliorate disease progression in chronically hypoxic piglets. Normoxic (control) and hypoxic piglets were studied. Some hypoxic piglets received oral sapropterin starting on day 3 of hypoxia and continued throughout an additional 7 days of hypoxic exposure. Catheters were placed for hemodynamic measurements, and pulmonary arteries were dissected to assess eNOS dimer-to-monomer ratios (a measure of eNOS coupling), NO production, and superoxide (O2·-) generation. Although higher than in normoxic controls, pulmonary vascular resistance was lower in sapropterin-treated hypoxic piglets than in untreated hypoxic piglets. Consistent with eNOS recoupling, eNOS dimer-to-monomer ratios and NO production were greater and O2·- generation was less in pulmonary arteries from sapropterin-treated than untreated hypoxic animals. When started after disease onset, oral sapropterin treatment inhibits chronic hypoxia-induced pulmonary hypertension at least in part by recoupling eNOS in the pulmonary vasculature of newborn piglets. Rescue treatment with sapropterin may be an effective strategy to inhibit further development of pulmonary hypertension in newborn infants suffering from chronic cardiopulmonary conditions associated with episodes of prolonged hypoxia.
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Affiliation(s)
- Anna Dikalova
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, Tennessee; and Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Judy L Aschner
- Department of Pediatrics, Albert Einstein College of Medicine and the Children's Hospital at Montefiore, New York, New York
| | - Mark R Kaplowitz
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Pediatrics, the University of Utah School of Medicine, Salt Lake City, Utah; and
| | - Marshall Summar
- Division of Genetics and Metabolism, Children's National Medical Center, Washington, District of Columbia
| | - Candice D Fike
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee; Department of Pediatrics, the University of Utah School of Medicine, Salt Lake City, Utah; and
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25
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Stewart CR, Obi N, Epane EC, Akbari AA, Halpern L, Southerland JH, Gangula PR. Effects of Diabetes on Salivary Gland Protein Expression of Tetrahydrobiopterin and Nitric Oxide Synthesis and Function. J Periodontol 2016; 87:735-41. [PMID: 26777763 PMCID: PMC4882217 DOI: 10.1902/jop.2016.150639] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Xerostomia is defined as dry mouth resulting from a change in the amount or composition of saliva and is often a major oral health complication associated with diabetes mellitus (DM). Studies have shown that xerostomia is more common in females at the onset of DM. Evidence suggests that nitric oxide (NO) plays a critical role in healthy salivary gland function. However, the specific mechanisms by which NO regulates salivary gland function at the onset of DM have yet to be determined. This study has two aims: 1) to determine whether protein expression or dimerization of NO synthase enzymes (neuronal [nNOS] and endothelial [eNOS]) are altered in the onset of diabetic xerostomia; and 2) to determine whether the changes in nNOS/eNOS protein expression or dimerization are correlated with changes in NO cofactor tetrahydrobiopterin (BH4) biosynthetic enzymes (guanosine triphosphate cyclohydrolase-1 and dihydrofolate reductase). METHODS Functional and Western blot studies were performed in streptozotocin-induced and control Sprague-Dawley female rats with DM (type 1 [t1DM]) using standardized protocols. Confirmation of xerostomia was determined by increased water intake and decreased salivary flow rate. RESULTS The results showed that in female rats with DM, salivary hypofunction is correlated with decreased submandibular and parotid gland sizes. The results also show a decrease in NOS and BH4 biosynthetic enzyme in submandibular glands. CONCLUSIONS These results indicate that a decrease in submandibular NO-BH4 protein expression may provide insight pertaining to mechanisms for the development of hyposalivation in DM-induced xerostomia. Furthermore, understanding the role of the NO-BH4 pathway may give insight into possible treatment options for the patient with DM experiencing xerostomia.
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Affiliation(s)
| | - Nneka Obi
- School of Dentistry, Meharry Medical College, Nashville, TN
| | - Elodie C Epane
- School of Dentistry, Meharry Medical College, Nashville, TN
| | | | - Leslie Halpern
- Department of Oral Surgery, School of Dentistry, Meharry Medical College
| | | | - Pandu R Gangula
- School of Dentistry, Meharry Medical College, Nashville, TN
- Center for Women's Health Research, School of Medicine, Meharry Medical College
- Department of Physiology, School of Medicine, Meharry Medical College
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Cheng F, Lan J, Xia W, Tu C, Chen B, Li S, Pan W. Folic Acid Attenuates Vascular Endothelial Cell Injury Caused by Hypoxia via the Inhibition of ERK1/2/NOX4/ROS Pathway. Cell Biochem Biophys 2016; 74:205-11. [PMID: 26906511 DOI: 10.1007/s12013-016-0723-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/29/2016] [Indexed: 11/25/2022]
Abstract
Coronary artery disease is a disease with high morbidity and mortality, in which vascular endothelial dysfunction plays an important role. Hypoxia leads to the inflammation and oxidative stress in endothelial cells, which results in the endothelial injury. The present study was designed to investigate the protective effect and mechanism of folic acid on hypoxia-induced injury in human umbilical vein endothelial cells (HUVEC). Cell counting Kit was used to detect cell survival rate, and apoptotic cells were detected by Hoechst 33258 staining. Intracellular reactive oxygen species (ROS) level was measured using dichloro-dihydro-fluorescein diacetate staining. Western blot was used to determine the protein expressions of extracellular signal protein kinase 1/2 (ERK1/2) and phosphorylated ERK1/2 (p-ERK1/2), NOX4 subunit of NAPDH and endothelial nitric oxide synthase (eNOS). Folic acid significantly increased the cell survival rate and decreased the apoptosis of HUVECs treated with folic acid compared with hypoxia-treated HUVEC. Folic acid also decreased ROS level, while it increased the nitrite content in HUVECs. In addition, folic acid decreased protein expressions of NOX4 and p-ERK1/2, while it increased the protein expression of eNOS in HUVECs. Furthermore, N-acetyl cysteine (NAC), the antioxidant, had similar effect on the cell survival rate and the apoptosis. In addition, DPI (NOX4 inhibitor) and U0126 (ERK1/2 inhibitor) rather than NAC decreased the protein expression of NOX4. NAC, DPI, and U0126 increased the protein expression of eNOS. Furthermore, U0126 rather than DPI and NAC decreased the protein expression of p-ERK1/2. Taken together, the results suggested that hypoxia decreased the cell survival rate and induced apoptosis via ERK1/2/NOX4/ROS pathway, which could be the target of folic acid in protecting the HUVECs from injury caused by hypoxia.
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Affiliation(s)
- Fei Cheng
- Department of Cardiovascular Medicine, Dongguan Third People's Hospital, No. 1 Xianglong Road, Shilong Town, Dongguan, 523326, China
| | - Jun Lan
- Department of Cardiovascular Medicine, Dongguan Third People's Hospital, No. 1 Xianglong Road, Shilong Town, Dongguan, 523326, China
| | - Wenhao Xia
- Department of Hypertension and Vascular Disease, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, 510080, China
| | - Chang Tu
- Department of Cardiovascular Medicine, Dongguan Third People's Hospital, No. 1 Xianglong Road, Shilong Town, Dongguan, 523326, China
| | - Benfa Chen
- Department of Cardiovascular Medicine, Dongguan Third People's Hospital, No. 1 Xianglong Road, Shilong Town, Dongguan, 523326, China
| | - Shicheng Li
- Department of Cardiovascular Medicine, Dongguan Third People's Hospital, No. 1 Xianglong Road, Shilong Town, Dongguan, 523326, China
| | - Weibiao Pan
- Department of Cardiovascular Medicine, Dongguan Third People's Hospital, No. 1 Xianglong Road, Shilong Town, Dongguan, 523326, China.
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Abstract
Atherosclerotic coronary artery disease (CAD) is a major cause of morbidity and mortality in the developed world. Endothelial dysfunction plays an important role in the development of atherosclerosis and predicts cardiovascular (CV) outcomes independent of conventional CV risk factors. In recent years, there have been tremendous improvements in the pharmacological prevention and management of CAD. In this review, the pathophysiology of endothelial dysfunction in relation to CAD is discussed and various techniques of invasive and noninvasive assessments of peripheral and coronary endothelial function described. In addition, evidence for the association of endothelial dysfunction and CV outcomes has been examined and finally the role of therapeutic interventions in endothelial dysfunction has been discussed.
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Leiva A, Fuenzalida B, Westermeier F, Toledo F, Salomón C, Gutiérrez J, Sanhueza C, Pardo F, Sobrevia L. Role for Tetrahydrobiopterin in the Fetoplacental Endothelial Dysfunction in Maternal Supraphysiological Hypercholesterolemia. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:5346327. [PMID: 26697136 PMCID: PMC4677232 DOI: 10.1155/2016/5346327] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 08/23/2015] [Indexed: 02/07/2023]
Abstract
Maternal physiological hypercholesterolemia occurs during pregnancy, ensuring normal fetal development. In some cases, the maternal plasma cholesterol level increases to above this physiological range, leading to maternal supraphysiological hypercholesterolemia (MSPH). This condition results in endothelial dysfunction and atherosclerosis in the fetal and placental vasculature. The fetal and placental endothelial dysfunction is related to alterations in the L-arginine/nitric oxide (NO) pathway and the arginase/urea pathway and results in reduced NO production. The level of tetrahydrobiopterin (BH4), a cofactor for endothelial NO synthase (eNOS), is reduced in nonpregnant women who have hypercholesterolemia, which favors the generation of the superoxide anion rather than NO (from eNOS), causing endothelial dysfunction. However, it is unknown whether MSPH is associated with changes in the level or metabolism of BH4; as a result, eNOS function is not well understood. This review summarizes the available information on the potential link between MSPH and BH4 in causing human fetoplacental vascular endothelial dysfunction, which may be crucial for understanding the deleterious effects of MSPH on fetal growth and development.
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Affiliation(s)
- Andrea Leiva
- Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, 8330024 Santiago, Chile
| | - Bárbara Fuenzalida
- Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, 8330024 Santiago, Chile
| | - Francisco Westermeier
- Advanced Center for Chronic Diseases (ACCDiS), Faculty of Chemical & Pharmaceutical Sciences and Faculty of Medicine, Universidad de Chile, 8380492 Santiago, Chile
- Faculty of Science, Universidad San Sebastián, 7510157 Santiago, Chile
| | - Fernando Toledo
- Department of Basic Sciences, Faculty of Sciences, Universidad del Bío-Bío, 3780000 Chillán, Chile
| | - Carlos Salomón
- University of Queensland Centre for Clinical Research (UQCCR), Faculty of Medicine and Biomedical Sciences, University of Queensland, Herston, QLD 4029, Australia
| | - Jaime Gutiérrez
- Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, 8330024 Santiago, Chile
- Cellular Signaling and Differentiation Laboratory (CSDL), Health Sciences Faculty, Universidad San Sebastian, 7510157 Santiago, Chile
| | - Carlos Sanhueza
- Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, 8330024 Santiago, Chile
| | - Fabián Pardo
- Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, 8330024 Santiago, Chile
| | - Luis Sobrevia
- Cellular and Molecular Physiology Laboratory (CMPL), Division of Obstetrics and Gynaecology, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, 8330024 Santiago, Chile
- University of Queensland Centre for Clinical Research (UQCCR), Faculty of Medicine and Biomedical Sciences, University of Queensland, Herston, QLD 4029, Australia
- Department of Physiology, Faculty of Pharmacy, Universidad de Sevilla, 41012 Seville, Spain
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Hsieh J, Trajcevski KE, Farr SL, Baker CL, Lake EJ, Taher J, Iqbal J, Hussain MM, Adeli K. Glucagon-Like Peptide 2 (GLP-2) Stimulates Postprandial Chylomicron Production and Postabsorptive Release of Intestinal Triglyceride Storage Pools via Induction of Nitric Oxide Signaling in Male Hamsters and Mice. Endocrinology 2015; 156:3538-47. [PMID: 26132919 DOI: 10.1210/en.2015-1110] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The intestinal overproduction of apolipoprotein B48 (apoB48)-containing chylomicron particles is a common feature of diabetic dyslipidemia and contributes to cardiovascular risk in insulin resistant states. We previously reported that glucagon-like peptide-2 (GLP-2) is a key endocrine stimulator of enterocyte fat absorption and chylomicron output in the postprandial state. GLP-2's stimulatory effect on chylomicron production in the postabsorptive state has been confirmed in human studies. The mechanism by which GLP-2 regulates chylomicron production is unclear, because its receptor is not expressed on enterocytes. We provide evidence for a key role of nitric oxide (NO) in mediating the stimulatory effects of GLP-2 during the postprandial and postabsorptive periods. Intestinal chylomicron production was assessed in GLP-2-treated hamsters administered the pan-specific NO synthase (NOS) inhibitor L-N(G)-nitroarginine methyl ester (L-NAME), and in GLP-2-treated endothelial NOS knockout mice. L-NAME blocked GLP-2-stimulated apoB48 secretion and reduced triglycerides (TGs) in the TG-rich lipoprotein (TRL) fraction of the plasma in the postprandial state. Endothelial NOS-deficient mice were resistant to GLP-2 stimulation and secreted fewer large apoB48-particles. When TG storage pools were allowed to accumulate, L-NAME mitigated the GLP-2-mediated increase in TRL-TG, suggesting that NO is required for early mobilization and secretion of stored TG and preformed chylomicrons. Importantly, the NO donor S-nitroso-L-glutathione was able to elicit an increase in TRL-TG in vivo and stimulate chylomicron release in vitro in primary enterocytes. We describe a novel role for GLP-2-mediated NO-signaling as a critical regulator of intestinal lipid handling and a potential contributor to postprandial dyslipidemia.
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Affiliation(s)
- Joanne Hsieh
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Karin E Trajcevski
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Sarah L Farr
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Christopher L Baker
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Elizabeth J Lake
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Jennifer Taher
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Jahangir Iqbal
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Mahmood M Hussain
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
| | - Khosrow Adeli
- Molecular Structure and Function (J.H., K.E.T., S.L.F., C.L.B., E.J.L., J.T., K.A.), Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada, M5G 1X8; Departments of Biochemistry (J.H., K.E.T., K.A.) and Laboratory Medicine and Pathobiology (S.L.F., J.T., K.A.), University of Toronto, Toronto, Ontario, Canada, M5S 1A8; and State University of New York Downstate Medical Center (J.I., M.H.H.), Brooklyn, New York 11203
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Suvorava T, Nagy N, Pick S, Lieven O, Rüther U, Dao VTV, Fischer JW, Weber M, Kojda G. Impact of eNOS-Dependent Oxidative Stress on Endothelial Function and Neointima Formation. Antioxid Redox Signal 2015; 23:711-23. [PMID: 25764009 PMCID: PMC4580305 DOI: 10.1089/ars.2014.6059] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 03/03/2015] [Accepted: 03/11/2015] [Indexed: 12/14/2022]
Abstract
AIMS Vascular oxidative stress generated by endothelial NO synthase (eNOS) was observed in experimental and clinical cardiovascular disease, but its relative importance for vascular pathologies is unclear. We investigated the impact of eNOS-dependent vascular oxidative stress on endothelial function and on neointimal hyperplasia. RESULTS A dimer-destabilized mutant of bovine eNOS where cysteine 101 was replaced by alanine was cloned and introduced into an eNOS-deficient mouse strain (eNOS-KO) in an endothelial-specific manner. Destabilization of mutant eNOS in cells and eNOS-KO was confirmed by the reduced dimer/monomer ratio. Purified mutant eNOS and transfected cells generated less citrulline and NO, respectively, while superoxide generation was enhanced. In eNOS-KO, introduction of mutant eNOS caused a 2.3-3.7-fold increase in superoxide and peroxynitrite formation in the aorta and myocardium. This was completely blunted by an NOS inhibitor. Nevertheless, expression of mutant eNOS in eNOS-KO completely restored maximal aortic endothelium-dependent relaxation to acetylcholine. Neointimal hyperplasia induced by carotid binding was much larger in eNOS-KO than in mutant eNOS-KO and C57BL/6, while the latter strains showed comparable hyperplasia. Likewise, vascular remodeling was blunted in eNOS-KO only. INNOVATION Our results provide the first in vivo evidence that eNOS-dependent oxidative stress is unlikely to be an initial cause of impaired endothelium-dependent vasodilation and/or a pathologic factor promoting intimal hyperplasia. These findings highlight the importance of other sources of vascular oxidative stress in cardiovascular disease. CONCLUSION eNOS-dependent oxidative stress is unlikely to induce functional vascular damage as long as concomitant generation of NO is preserved. This underlines the importance of current and new therapeutic strategies in improving endothelial NO generation.
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Affiliation(s)
- Tatsiana Suvorava
- Institute for Pharmacology and Clinical Pharmacology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Nadine Nagy
- Institute for Pharmacology and Clinical Pharmacology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Stephanie Pick
- Institute for Pharmacology and Clinical Pharmacology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Oliver Lieven
- Institute for Animal Developmental and Molecular Biology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Ulrich Rüther
- Institute for Animal Developmental and Molecular Biology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Vu Thao-Vi Dao
- Institute for Pharmacology and Clinical Pharmacology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Jens W. Fischer
- Institute for Pharmacology and Clinical Pharmacology, Heinrich-Heine-University, Düsseldorf, Germany
| | - Martina Weber
- Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia
| | - Georg Kojda
- Institute for Pharmacology and Clinical Pharmacology, Heinrich-Heine-University, Düsseldorf, Germany
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Xie L, Talukder MAH, Sun J, Varadharaj S, Zweier JL. Liposomal tetrahydrobiopterin preserves eNOS coupling in the post-ischemic heart conferring in vivo cardioprotection. J Mol Cell Cardiol 2015; 86:14-22. [PMID: 26116866 PMCID: PMC4558339 DOI: 10.1016/j.yjmcc.2015.06.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 06/17/2015] [Accepted: 06/19/2015] [Indexed: 02/07/2023]
Abstract
Tetrahydrobiopterin (BH4) is an essential cofactor of nitric oxide synthase (NOS), and reduced BH4 availability leads to endothelial NOS (eNOS) uncoupling and increased reactive oxygen species (ROS) generation. Questions remain regarding the functional state of eNOS and role of BH4 availability in the process of in vivo myocardial ischemia-reperfusion (I/R) injury. Rats were subjected to 60min of in vivo left coronary artery occlusion and varying periods of reperfusion with or without pre-ischemic liposomal BH4 supplementation (1mg/kg, iv). Myocardial infarction was correlated with cardiac BH4 content, eNOS protein level, NOS enzyme activity, and ROS generation. In the vehicle group, 60-min ischemia drastically reduced myocardial BH4 content in the area at risk (AAR) compared to non-ischemic (NI) area and the level remained lower during early reperfusion followed by recovery after 24-h reperfusion. Total eNOS, activated eNOS protein level (eNOS Ser1177 phosphorylation) and NOS activity were also significantly reduced during ischemia and/or early reperfusion, but recovered after 24-h reperfusion. With liposomal BH4 treatment, BH4 levels were identical in the AAR and NI area during ischemia and/or early reperfusion, and were significantly higher than with vehicle. BH4 pre-treatment preserved eNOS Ser1177 phosphorylation and NOS activity in the AAR, and significantly reduced myocardial ROS generation and infarction compared to vehicle. These findings provide direct evidence that in vivo I/R induces eNOS dysfunction secondary to BH4 depletion, and that pre-ischemic liposomal BH4 administration preserves eNOS function conferring cardioprotection with reduced oxidative stress.
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Affiliation(s)
- Lin Xie
- Davis Heart and Lung Research Institute and Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH, USA; The Institute of Organ Transplantation, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - M A Hassan Talukder
- Davis Heart and Lung Research Institute and Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Jian Sun
- Davis Heart and Lung Research Institute and Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Saradhadevi Varadharaj
- Davis Heart and Lung Research Institute and Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Jay L Zweier
- Davis Heart and Lung Research Institute and Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, OH, USA.
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Benhamou Y, Miranda S, Armengol G, Harouki N, Drouot L, Zahr N, Thuillez C, Boyer O, Levesque H, Joannides R, Richard V. Infliximab improves endothelial dysfunction in a mouse model of antiphospholipid syndrome: Role of reduced oxidative stress. Vascul Pharmacol 2015; 71:93-101. [DOI: 10.1016/j.vph.2015.03.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 02/24/2015] [Accepted: 03/30/2015] [Indexed: 11/15/2022]
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Park J, Liao P, Sher S, Lyles RH, Deveaux DD, Quyyumi AA. Tetrahydrobiopterin lowers muscle sympathetic nerve activity and improves augmentation index in patients with chronic kidney disease. Am J Physiol Regul Integr Comp Physiol 2015; 308:R208-18. [PMID: 25477424 PMCID: PMC4313073 DOI: 10.1152/ajpregu.00409.2014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 12/01/2014] [Indexed: 11/22/2022]
Abstract
Chronic kidney disease (CKD) is characterized by overactivation of the sympathetic nervous system (SNS) that contributes to cardiovascular risk. Decreased nitric oxide (NO) bioavailability is a major factor contributing to SNS overactivity in CKD, since reduced neuronal NO leads to increased central SNS activity. Tetrahydrobiopterin (BH4) is an essential cofactor for nitric oxide synthase that increases NO bioavailability in experimental models of CKD. We conducted a randomized, double-blinded, placebo-controlled trial testing the benefits of oral sapropterin dihydrochloride (6R-BH4, a synthetic form of BH4) in CKD. 36 patients with CKD and hypertension were randomized to 12 wk of 1) 200 mg 6R-BH4 twice daily + 1 mg folic acid once daily; vs. 2) placebo + folic acid. The primary endpoint was a change in resting muscle sympathetic nerve activity (MSNA). Secondary endpoints included arterial stiffness using pulse wave velocity (PWV) and augmentation index (AIx), endothelial function using brachial artery flow-mediated dilation and endothelial progenitor cells, endothelium-independent vasodilatation (EID), microalbuminuria, and blood pressure. We observed a significant reduction in MSNA after 12 wk of 6R-BH4 (-7.5 ± 2.1 bursts/min vs. +3.2 ± 1.3 bursts/min; P = 0.003). We also observed a significant improvement in AIx (by -5.8 ± 2.0% vs. +1.8 ± 1.7 in the placebo group, P = 0.007). EID increased significantly (by +2.0 ± 0.59%; P = 0.004) in the 6R-BH4 group, but there was no change in endothelial function. There was a trend toward a reduction in diastolic blood pressure by -4 ± 3 mmHg at 12 wk with 6R-BH4 (P = 0.055). 6R-BH4 treatment may have beneficial effects on SNS activity and central pulse wave reflections in hypertensive patients with CKD.
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Affiliation(s)
- Jeanie Park
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; Research Service Line, Department of Veterans Affairs Medical Center, Decatur, Georgia;
| | - Peizhou Liao
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia; and
| | - Salman Sher
- Cardiology Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - Robert H Lyles
- Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia; and
| | - Don D Deveaux
- Renal Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; Research Service Line, Department of Veterans Affairs Medical Center, Decatur, Georgia
| | - Arshed A Quyyumi
- Cardiology Division, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
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Tetrahydrobiopterin improves endothelial function in cardiovascular disease: a systematic review. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 2014:850312. [PMID: 25548592 PMCID: PMC4273464 DOI: 10.1155/2014/850312] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 11/20/2014] [Indexed: 11/18/2022]
Abstract
Background. Tetrahydrobiopterin (BH4) is a cofactor of nitric oxide synthase (NOS). Nitric oxide (NO) bioavailability is reduced during the early stage of vascular diseases, such as coronary artery disease, hypercholesterolemia, hypertension, and diabetic vasculopathy, and even throughout the entire progression of atherosclerosis. Methods. A literature search was performed using electronic databases (up to January 31, 2014), including MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL), using an established strategy. Results. Fourteen articles were selected with a total of 370 patients. Ten of the fourteen studies showed a significant improvement in the endothelial dysfunction of various cardiovascular disease groups with BH4 supplementation compared with the control groups or placebos. Three studies showed no positive outcome, and one study showed that low-dose BH4 had no effect but that high-dose BH4 did have a significantly different result. Conclusions. This review concludes that supplementation with BH4 and/or augmentation of the endogenous levels of BH4 will be a novel approach to improve the endothelial dysfunction observed in various cardiovascular diseases. BH4 might be considered to be a new therapeutic agent to prevent the initiation and progression of cardiovascular disease.
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Cardini B, Watschinger K, Hermann M, Obrist P, Oberhuber R, Brandacher G, Chuaiphichai S, Channon KM, Pratschke J, Maglione M, Werner ER. Crucial role for neuronal nitric oxide synthase in early microcirculatory derangement and recipient survival following murine pancreas transplantation. PLoS One 2014; 9:e112570. [PMID: 25389974 PMCID: PMC4229216 DOI: 10.1371/journal.pone.0112570] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Accepted: 10/08/2014] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE Aim of this study was to identify the nitric oxide synthase (NOS) isoform involved in early microcirculatory derangements following solid organ transplantation. BACKGROUND Tetrahydrobiopterin donor treatment has been shown to specifically attenuate these derangements following pancreas transplantation, and tetrahydrobiopterin-mediated protective effects to rely on its NOS-cofactor activity, rather than on its antioxidant capacity. However, the NOS-isoform mainly involved in this process has still to be defined. METHODS Using a murine pancreas transplantation model, grafts lacking one of the three NOS-isoforms were compared to grafts from wild-type controls. Donors were treated with either tetrahydrobiopterin or remained untreated. All grafts were subjected to 16 h cold ischemia time and transplanted into wild-type recipients. Following 4 h graft reperfusion, microcirculation was analysed by confocal intravital fluorescence microscopy. Recipient survival was monitored for 50 days. RESULTS Transplantation of the pancreas from untreated wild-type donor mice resulted in microcirculatory damage of the transplanted graft and no recipient survived more than 72 h. Transplanting grafts from untreated donor mice lacking either endothelial or inducible NOS led to similar outcomes. In contrast, donor treatment with tetrahydrobiopterin prevented microcirculatory breakdown enabling long-term survival. Sole exception was transplantation of grafts from untreated donor mice lacking neuronal NOS. It resulted in intact microvascular structure and long-term recipient survival, either if donor mice were untreated or treated with tetrahydrobiopterin. CONCLUSION We demonstrate for the first time the crucial involvement of neuronal NOS in early microcirculatory derangements following solid organ transplantation. In this model, protective effects of tetrahydrobiopterin are mediated by targeting this isoform.
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Affiliation(s)
- Benno Cardini
- Center of Operative Medicine, Department of Visceral, Transplant and Thoracic Surgery, Innsbruck Medical University, Innsbruck, Austria
- Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Katrin Watschinger
- Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Martin Hermann
- Department of Anaesthesiology and Critical Care Medicine, Innsbruck Medical University, Innsbruck, Austria
| | - Peter Obrist
- Institute of Pathology, St. Vinzenz Krankenhaus, Zams, Austria
| | - Rupert Oberhuber
- Center of Operative Medicine, Department of Visceral, Transplant and Thoracic Surgery, Innsbruck Medical University, Innsbruck, Austria
| | - Gerald Brandacher
- Center of Operative Medicine, Department of Visceral, Transplant and Thoracic Surgery, Innsbruck Medical University, Innsbruck, Austria
- Department of Plastic and Reconstructive Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Surawee Chuaiphichai
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Keith M. Channon
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Johann Pratschke
- Center of Operative Medicine, Department of Visceral, Transplant and Thoracic Surgery, Innsbruck Medical University, Innsbruck, Austria
| | - Manuel Maglione
- Center of Operative Medicine, Department of Visceral, Transplant and Thoracic Surgery, Innsbruck Medical University, Innsbruck, Austria
| | - Ernst R. Werner
- Division of Biological Chemistry, Biocenter, Innsbruck Medical University, Innsbruck, Austria
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Ma S, Ma CCH. Recent developments in the effects of nitric oxide-donating statins on cardiovascular disease through regulation of tetrahydrobiopterin and nitric oxide. Vascul Pharmacol 2014; 63:63-70. [PMID: 25139660 DOI: 10.1016/j.vph.2014.08.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2014] [Revised: 08/01/2014] [Accepted: 08/04/2014] [Indexed: 10/24/2022]
Abstract
Since the discovery of the importance of nitric oxide (NO) to the human body three decades ago, numerous laboratory and clinical studies have been done to explore its potential therapeutic actions on many organs. In the cardiovascular system, NO works as a volatile signaling molecule regulating the vascular permeability and vascular tone, preventing thrombosis and inflammation, as well as inhibiting the smooth muscle hyperplasia. Thus, NO is important in the prevention and treatment of cardiovascular disease. NO is synthesized by NO synthase (NOS) with tetrahydrobiopterin (BH4) as the crucial cofactor. Many studies have been done to form nitric oxide donors so as to deliver NO directly to the vessel walls. In addition, NO moieties have been incorporated into existing therapeutic agents to enhance the NO bioavailability, including statins. Statins are inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme (HMG-CoA), the rate-limiting enzyme of the mevalonate pathway. By inhibiting this pathway, statins lower blood cholesterol and exert their pleiotropic effects through activity in reaction cascades, such as Rho/ROCK and Rac 1/NADPH oxidase pathways. Statins have also been observed to implement their non-lipid effects by promoting BH4 synthesis with increase of NO bioavailability. Furthermore, NO-donating statins in laboratory studies have demonstrated to produce better therapeutic effects than their parent's drugs. They offer better anti-inflammatory, anti-proliferative and antithrombotic actions on cardiovascular system. They also cause better revascularization in peripheral ischemia and produce greater enhancement in limb reperfusion and salvage. In addition, it has been shown that NO-donating statin caused less myotoxicity, the most common side effect related to treatment with statins. The initial studies have demonstrated the superior therapeutic effects of NO-donating statins while producing fewer side effects.
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Affiliation(s)
- Sze Ma
- Hong Kong Baptist Hospital, Hong Kong; National University Ireland, Ireland; Royal College of Physicians of Ireland, Ireland
| | - Christopher Cheng-Hwa Ma
- NHS Dumfries & Galloway, GMC 7411692, United Kingdom; King's College London School of Medicine, United Kingdom.
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Shi Y, Lüscher TF, Camici GG. Dual role of endothelial nitric oxide synthase in oxidized LDL-induced, p66Shc-mediated oxidative stress in cultured human endothelial cells. PLoS One 2014; 9:e107787. [PMID: 25247687 PMCID: PMC4172699 DOI: 10.1371/journal.pone.0107787] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 08/21/2014] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND The aging gene p66Shc, is an important mediator of oxidative stress-induced vascular dysfunction and disease. In cultured human aortic endothelial cells (HAEC), p66Shc deletion increases endothelial nitric oxide synthase (eNOS) expression and nitric oxide (NO) bioavailability via protein kinase B. However, the putative role of the NO pathway on p66Shc activation remains unclear. This study was designed to elucidate the regulatory role of the eNOS/NO pathway on p66Shc activation. METHODS AND RESULTS Incubation of HAEC with oxidized low density lipoprotein (oxLDL) led to phosphorylation of p66Shc at Ser-36, resulting in an enhanced production of superoxide anion (O2-). In the absence of oxLDL, inhibition of eNOS by small interfering RNA or L-NAME, induced p66Shc phosphorylation, suggesting that basal NO production inhibits O2- production. oxLDL-induced, p66Shc-mediated O2- was prevented by eNOS inhibition, suggesting that when cells are stimulated with oxLDL eNOS is a source of reactive oxygen species. Endogenous or exogenous NO donors, prevented p66Shc activation and reduced O2- production. Treatment with tetrahydrobiopterin, an eNOS cofactor, restored eNOS uncoupling, prevented p66Shc activation, and reduced O2- generation. However, late treatment with tetrahydropterin did not yield the same result suggesting that eNOS uncoupling is the primary source of reactive oxygen species. CONCLUSIONS The present study reports that in primary cultured HAEC treated with oxLDL, p66Shc-mediated oxidative stress is derived from eNOS uncoupling. This finding contributes novel information on the mechanisms of p66Shc activation and its dual interaction with eNOS underscoring the importance eNOS uncoupling as a putative antioxidant therapeutical target in endothelial dysfunction as observed in cardiovascular disease.
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Affiliation(s)
- Yi Shi
- Cardiology, University Heart Center, University Hospital Zürich and Center for Molecular Cardiology, Campus Schlieren, University of Zurich, Zurich, Switzerland
- Center for Integrative Human Physiology (ZHIP), University of Zurich, Zurich, Switzerland
- Biomedical Research Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Thomas F. Lüscher
- Cardiology, University Heart Center, University Hospital Zürich and Center for Molecular Cardiology, Campus Schlieren, University of Zurich, Zurich, Switzerland
- Center for Integrative Human Physiology (ZHIP), University of Zurich, Zurich, Switzerland
| | - Giovanni G. Camici
- Cardiology, University Heart Center, University Hospital Zürich and Center for Molecular Cardiology, Campus Schlieren, University of Zurich, Zurich, Switzerland
- Center for Integrative Human Physiology (ZHIP), University of Zurich, Zurich, Switzerland
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Qiu S, Mintz JD, Salet CD, Han W, Giannis A, Chen F, Yu Y, Su Y, Fulton DJ, Stepp DW. Increasing muscle mass improves vascular function in obese (db/db) mice. J Am Heart Assoc 2014; 3:e000854. [PMID: 24965025 PMCID: PMC4309080 DOI: 10.1161/jaha.114.000854] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background A sedentary lifestyle is an independent risk factor for cardiovascular disease and exercise has been shown to ameliorate this risk. Inactivity is associated with a loss of muscle mass, which is also reversed with isometric exercise training. The relationship between muscle mass and vascular function is poorly defined. The aims of the current study were to determine whether increasing muscle mass by genetic deletion of myostatin, a negative regulator of muscle growth, can influence vascular function in mesenteric arteries from obese db/db mice. Methods and Results Myostatin expression was elevated in skeletal muscle of obese mice and associated with reduced muscle mass (30% to 50%). Myostatin deletion increased muscle mass in lean (40% to 60%) and obese (80% to 115%) mice through increased muscle fiber size (P<0.05). Myostatin deletion decreased adipose tissue in lean mice, but not obese mice. Markers of insulin resistance and glucose tolerance were improved in obese myostatin knockout mice. Obese mice demonstrated an impaired endothelial vasodilation, compared to lean mice. This impairment was improved by superoxide dismutase mimic Tempol. Deletion of myostatin improved endothelial vasodilation in mesenteric arteries in obese, but not in lean, mice. This improvement was blunted by nitric oxide (NO) synthase inhibitor l‐NG‐nitroarginine methyl ester (l‐NAME). Prostacyclin (PGI2)‐ and endothelium‐derived hyperpolarizing factor (EDHF)‐mediated vasodilation were preserved in obese mice and unaffected by myostatin deletion. Reactive oxygen species) was elevated in the mesenteric endothelium of obese mice and down‐regulated by deletion of myostatin in obese mice. Impaired vasodilation in obese mice was improved by NADPH oxidase inhibitor (GKT136901). Treatment with sepiapterin, which increases levels of tetrahydrobiopterin, improved vasodilation in obese mice, an improvement blocked by l‐NAME. Conclusions Increasing muscle mass by genetic deletion of myostatin improves NO‐, but not PGI2‐ or EDHF‐mediated vasodilation in obese mice; this vasodilation improvement is mediated by down‐regulation of superoxide.
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Affiliation(s)
- Shuiqing Qiu
- Vascular Biology Center and Department of Physiology, Georgia Regents University, Augusta, GA, Germany (S.Q., J.D.M., C.D.S., W.H., A.G., F.C., Y.Y., Y.S., D.J.F., D.W.S.)
| | - James D Mintz
- Vascular Biology Center and Department of Physiology, Georgia Regents University, Augusta, GA, Germany (S.Q., J.D.M., C.D.S., W.H., A.G., F.C., Y.Y., Y.S., D.J.F., D.W.S.)
| | - Christina D Salet
- Vascular Biology Center and Department of Physiology, Georgia Regents University, Augusta, GA, Germany (S.Q., J.D.M., C.D.S., W.H., A.G., F.C., Y.Y., Y.S., D.J.F., D.W.S.)
| | - Weihong Han
- Vascular Biology Center and Department of Physiology, Georgia Regents University, Augusta, GA, Germany (S.Q., J.D.M., C.D.S., W.H., A.G., F.C., Y.Y., Y.S., D.J.F., D.W.S.) Department of Physiology, Georgia Regents University, Augusta, GA, Germany (W.H., Y.S.)
| | - Athanassios Giannis
- Vascular Biology Center and Department of Physiology, Georgia Regents University, Augusta, GA, Germany (S.Q., J.D.M., C.D.S., W.H., A.G., F.C., Y.Y., Y.S., D.J.F., D.W.S.) Institute of Organic Chemistry, University of Leipzig, Leipzig, Germany (A.G.)
| | - Feng Chen
- Vascular Biology Center and Department of Physiology, Georgia Regents University, Augusta, GA, Germany (S.Q., J.D.M., C.D.S., W.H., A.G., F.C., Y.Y., Y.S., D.J.F., D.W.S.)
| | - Yanfang Yu
- Vascular Biology Center and Department of Physiology, Georgia Regents University, Augusta, GA, Germany (S.Q., J.D.M., C.D.S., W.H., A.G., F.C., Y.Y., Y.S., D.J.F., D.W.S.)
| | - Yunchao Su
- Vascular Biology Center and Department of Physiology, Georgia Regents University, Augusta, GA, Germany (S.Q., J.D.M., C.D.S., W.H., A.G., F.C., Y.Y., Y.S., D.J.F., D.W.S.) Department of Physiology, Georgia Regents University, Augusta, GA, Germany (W.H., Y.S.)
| | - David J Fulton
- Vascular Biology Center and Department of Physiology, Georgia Regents University, Augusta, GA, Germany (S.Q., J.D.M., C.D.S., W.H., A.G., F.C., Y.Y., Y.S., D.J.F., D.W.S.)
| | - David W Stepp
- Vascular Biology Center and Department of Physiology, Georgia Regents University, Augusta, GA, Germany (S.Q., J.D.M., C.D.S., W.H., A.G., F.C., Y.Y., Y.S., D.J.F., D.W.S.)
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Bendall JK, Douglas G, McNeill E, Channon KM, Crabtree MJ. Tetrahydrobiopterin in cardiovascular health and disease. Antioxid Redox Signal 2014; 20:3040-77. [PMID: 24294830 PMCID: PMC4038990 DOI: 10.1089/ars.2013.5566] [Citation(s) in RCA: 164] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 11/01/2013] [Accepted: 12/02/2013] [Indexed: 01/03/2023]
Abstract
Tetrahydrobiopterin (BH4) functions as a cofactor for several important enzyme systems, and considerable evidence implicates BH4 as a key regulator of endothelial nitric oxide synthase (eNOS) in the setting of cardiovascular health and disease. BH4 bioavailability is determined by a balance of enzymatic de novo synthesis and recycling, versus degradation in the setting of oxidative stress. Augmenting vascular BH4 levels by pharmacological supplementation has been shown in experimental studies to enhance NO bioavailability. However, it has become more apparent that the role of BH4 in other enzymatic pathways, including other NOS isoforms and the aromatic amino acid hydroxylases, may have a bearing on important aspects of vascular homeostasis, inflammation, and cardiac function. This article reviews the role of BH4 in cardiovascular development and homeostasis, as well as in pathophysiological processes such as endothelial and vascular dysfunction, atherosclerosis, inflammation, and cardiac hypertrophy. We discuss the therapeutic potential of BH4 in cardiovascular disease states and attempt to address how this modulator of intracellular NO-redox balance may ultimately provide a powerful new treatment for many cardiovascular diseases.
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Affiliation(s)
- Jennifer K Bendall
- Division of Cardiovascular Medicine, British Heart Foundation Centre of Research Excellence, University of Oxford , John Radcliffe Hospital, Oxford, United Kingdom
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Endothelial dysfunction in conduit arteries and in microcirculation. Novel therapeutic approaches. Pharmacol Ther 2014; 144:253-67. [PMID: 24928320 DOI: 10.1016/j.pharmthera.2014.06.003] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 05/28/2014] [Indexed: 11/22/2022]
Abstract
The vascular endothelium not only is a single monolayer of cells between the vessel lumen and the intimal wall, but also plays an important role by controlling vascular function and structure mainly via the production of nitric oxide (NO). The so called "cardiovascular risk factors" are associated with endothelial dysfunction, that reduces NO bioavailability, increases oxidative stress, and promotes inflammation contributing therefore to the development of atherosclerosis. The significant role of endothelial dysfunction in the development of atherosclerosis emphasizes the need for efficient therapeutic interventions. During the last years statins, angiotensin-converting enzyme inhibitors, angiotensin-receptor antagonists, antioxidants, beta-blockers and insulin sensitizers have been evaluated for their ability to restore endothelial function (Briasoulis et al., 2012). As there is not a straightforward relationship between therapeutic interventions and improvement of endothelial function but rather a complicated interrelationship between multiple cellular and sub-cellular targets, research has been focused on the understanding of the underlying mechanisms. Moreover, the development of novel diagnostic invasive and non-invasive methods has allowed the early detection of endothelial dysfunction expanding the role of therapeutic interventions and our knowledge. In the current review we present the available data concerning the contribution of endothelial dysfunction to atherogenesis and review the methods that assess endothelial function with a view to understand the multiple targets of therapeutic interventions. Finally we focus on the classic and novel therapeutic approaches aiming to improve endothelial dysfunction and the underlying mechanisms.
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Armitage ME, La M, Schmidt HHHW, Wingler K. Diagnosis and individual treatment of cardiovascular diseases: targeting vascular oxidative stress. Expert Rev Clin Pharmacol 2014; 3:639-48. [DOI: 10.1586/ecp.10.40] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Rajendran P, Rengarajan T, Thangavel J, Nishigaki Y, Sakthisekaran D, Sethi G, Nishigaki I. The vascular endothelium and human diseases. Int J Biol Sci 2013; 9:1057-69. [PMID: 24250251 PMCID: PMC3831119 DOI: 10.7150/ijbs.7502] [Citation(s) in RCA: 944] [Impact Index Per Article: 85.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 10/07/2013] [Indexed: 02/07/2023] Open
Abstract
Alterations of endothelial cells and the vasculature play a central role in the pathogenesis of a broad spectrum of the most dreadful of human diseases, as endothelial cells have the key function of participating in the maintenance of patent and functional capillaries. The endothelium is directly involved in peripheral vascular disease, stroke, heart disease, diabetes, insulin resistance, chronic kidney failure, tumor growth, metastasis, venous thrombosis, and severe viral infectious diseases. Dysfunction of the vascular endothelium is thus a hallmark of human diseases. In this review the main endothelial abnormalities found in various human diseases such as cancer, diabetes mellitus, atherosclerosis, and viral infections are addressed.
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Affiliation(s)
- Peramaiyan Rajendran
- 1. NPO-International Laboratory of Biochemistry,1-166, Uchide, Nakagawa-ku, Nagoya 454-0926, Japan
| | | | - Jayakumar Thangavel
- 2. Department of Pharmacology and Center of Lung and Vascular Biology, University of Illinois College of Medicine, Chicago, Illinois, United States of America
| | - Yutaka Nishigaki
- 1. NPO-International Laboratory of Biochemistry,1-166, Uchide, Nakagawa-ku, Nagoya 454-0926, Japan
| | - Dhanapal Sakthisekaran
- 3. Department of Medical Biochemistry, Dr. ALM PG Institute of Basic Medical Sciences, University of Madras, Taramani Campus, Chennai, India 600 113
| | - Gautam Sethi
- 4. Department of Pharmacology,Yong Loo Lin School of Medicine,National University Health System, 10 Medical Drive, MD11, #05-09, Clinical Research Centre, Singapore 117597
| | - Ikuo Nishigaki
- 1. NPO-International Laboratory of Biochemistry,1-166, Uchide, Nakagawa-ku, Nagoya 454-0926, Japan
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Benson MA, Batchelor H, Chuaiphichai S, Bailey J, Zhu H, Stuehr DJ, Bhattacharya S, Channon KM, Crabtree MJ. A pivotal role for tryptophan 447 in enzymatic coupling of human endothelial nitric oxide synthase (eNOS): effects on tetrahydrobiopterin-dependent catalysis and eNOS dimerization. J Biol Chem 2013; 288:29836-45. [PMID: 23965989 PMCID: PMC3795282 DOI: 10.1074/jbc.m113.493023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 08/12/2013] [Indexed: 11/06/2022] Open
Abstract
Tetrahydrobiopterin (BH4) is a required cofactor for the synthesis of NO by NOS. Bioavailability of BH4 is a critical factor in regulating the balance between NO and superoxide production by endothelial NOS (eNOS coupling). Crystal structures of the mouse inducible NOS oxygenase domain reveal a homologous BH4-binding site located in the dimer interface and a conserved tryptophan residue that engages in hydrogen bonding or aromatic stacking interactions with the BH4 ring. The role of this residue in eNOS coupling remains unexplored. We overexpressed human eNOS W447A and W447F mutants in novel cell lines with tetracycline-regulated expression of human GTP cyclohydrolase I, the rate-limiting enzyme in BH4 synthesis, to determine the importance of BH4 and Trp-447 in eNOS uncoupling. NO production was abolished in eNOS-W447A cells and diminished in cells expressing W447F, despite high BH4 levels. eNOS-derived superoxide production was significantly elevated in W447A and W447F versus wild-type eNOS, and this was sufficient to oxidize BH4 to 7,8-dihydrobiopterin. In uncoupled, BH4-deficient cells, the deleterious effects of W447A mutation were greatly exacerbated, resulting in further attenuation of NO and greatly increased superoxide production. eNOS dimerization was attenuated in W447A eNOS cells and further reduced in BH4-deficient cells, as demonstrated using a novel split Renilla luciferase biosensor. Reduction of cellular BH4 levels resulted in a switch from an eNOS dimer to an eNOS monomer. These data reveal a key role for Trp-447 in determining NO versus superoxide production by eNOS, by effects on BH4-dependent catalysis, and by modulating eNOS dimer formation.
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Affiliation(s)
- Matthew A. Benson
- the Nuffield Department of Clinical Medicine, Target Discovery Institute, The Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, United Kingdom, and
| | - Helen Batchelor
- From the British Heart Foundation Centre of Research Excellence, Division of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
| | - Surawee Chuaiphichai
- From the British Heart Foundation Centre of Research Excellence, Division of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
| | - Jade Bailey
- From the British Heart Foundation Centre of Research Excellence, Division of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
| | - Hanneng Zhu
- the Nuffield Department of Clinical Medicine, Target Discovery Institute, The Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford OX3 7BN, United Kingdom, and
| | - Dennis J. Stuehr
- the Department of Pathobiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195
| | - Shoumo Bhattacharya
- From the British Heart Foundation Centre of Research Excellence, Division of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
| | - Keith M. Channon
- From the British Heart Foundation Centre of Research Excellence, Division of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
| | - Mark J. Crabtree
- From the British Heart Foundation Centre of Research Excellence, Division of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
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Abstract
6R l-erythro-5,6,7,8-tetrahydrobiopterin (BH4) is an essential cofactor for several enzymes including phenylalanine hydroxylase and the nitric oxide synthases (NOS). Oral supplementation of BH4 has been successfully employed to treat subsets of patients with hyperphenylalaninaemia. More recently, research efforts have focussed on understanding whether BH4 supplementation may also be efficacious in cardiovascular disorders that are underpinned by reduced nitric oxide bioavailability. Whilst numerous preclinical and clinical studies have demonstrated a positive association between enhanced BH4 and vascular function, the efficacy of orally administered BH4 in human cardiovascular disease remains unclear. Furthermore, interventions that limit BH4 bioavailability may provide benefit in diseases where nitric oxide over production contributes to pathology. This review describes the pathways involved in BH4 bio-regulation and discusses other endogenous mechanisms that could be harnessed therapeutically to manipulate vascular BH4 levels.
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Affiliation(s)
- Anna Starr
- Pharmacology and Therapeutics Group, Institute of Pharmaceutical Science, School of Biomedical Sciences, King's College London, Franklin Wilkins Building, 150 Stamford Street,London SE1 9NH, United Kingdom
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McNeill E, Channon KM. The role of tetrahydrobiopterin in inflammation and cardiovascular disease. Thromb Haemost 2012; 108:832-9. [PMID: 23052970 PMCID: PMC5238931 DOI: 10.1160/th12-06-0424] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Accepted: 08/21/2012] [Indexed: 12/11/2022]
Abstract
The cofactor tetrahydrobiopterin (BH4) is required for nitric oxide (NO) production by all nitric oxide synthase (NOS) enzymes and is a key regulator of cellular redox signalling. When BH4 levels become limiting NOS enzymes become 'uncoupled' and produce superoxide rather than NO. Endothelial cell BH4 is required for the maintenance of vascular function through NO production, and reduced BH4 levels are associated with vascular dysfunction. Evidence increasingly points to important roles for BH4 and NOS enzymes in other vascular cell types. Leukocytes have a fundamental role in atherosclerosis, and new evidence points to a role in the control of hypertension. Leukocytes are a major site of iNOS expression, and the regulation of this isoform is another mechanism by which BH4 availability may modulate disease. This review provides an overview of BH4 control of NOS function in both endothelial cells and leukocytes in the context of vascular disease and current therapeutic evaluations.
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Affiliation(s)
- Eileen McNeill
- Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
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Cunnington C, Van Assche T, Shirodaria C, Kylintireas I, Lindsay AC, Lee JM, Antoniades C, Margaritis M, Lee R, Cerrato R, Crabtree MJ, Francis JM, Sayeed R, Ratnatunga C, Pillai R, Choudhury RP, Neubauer S, Channon KM. Systemic and vascular oxidation limits the efficacy of oral tetrahydrobiopterin treatment in patients with coronary artery disease. Circulation 2012; 125:1356-66. [PMID: 22315282 PMCID: PMC5238935 DOI: 10.1161/circulationaha.111.038919] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND The endothelial nitric oxide synthase cofactor tetrahydrobiopterin (BH4) plays a pivotal role in maintaining endothelial function in experimental vascular disease models and in humans. Augmentation of endogenous BH4 levels by oral BH4 treatment has been proposed as a potential therapeutic strategy in vascular disease states. We sought to determine the mechanisms relating exogenous BH4 to human vascular function and to determine oral BH4 pharmacokinetics in both plasma and vascular tissue in patients with coronary artery disease. METHODS AND RESULTS Forty-nine patients with coronary artery disease were randomized to receive low-dose (400 mg/d) or high-dose (700 mg/d) BH4 or placebo for 2 to 6 weeks before coronary artery bypass surgery. Vascular function was quantified by magnetic resonance imaging before and after treatment, along with plasma BH4 levels. Vascular superoxide, endothelial function, and BH4 levels were determined in segments of saphenous vein and internal mammary artery. Oral BH4 treatment significantly augmented BH4 levels in plasma and in saphenous vein (but not internal mammary artery) but also increased levels of the oxidation product dihydrobiopterin (BH2), which lacks endothelial nitric oxide synthase cofactor activity. There was no effect of BH4 treatment on vascular function or superoxide production. Supplementation of human vessels and blood with BH4 ex vivo revealed rapid oxidation of BH4 to BH2 with predominant BH2 uptake by vascular tissue. CONCLUSIONS Oral BH4 treatment augments total biopterin levels in patients with established coronary artery disease but has no net effect on vascular redox state or endothelial function owing to systemic and vascular oxidation of BH4. Alternative strategies are required to target BH4-dependent endothelial function in established vascular disease states.
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Affiliation(s)
- Colin Cunnington
- Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
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Moreau KL, Meditz A, Deane KD, Kohrt WM. Tetrahydrobiopterin improves endothelial function and decreases arterial stiffness in estrogen-deficient postmenopausal women. Am J Physiol Heart Circ Physiol 2012; 302:H1211-8. [PMID: 22245769 PMCID: PMC3311456 DOI: 10.1152/ajpheart.01065.2011] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 01/09/2012] [Indexed: 01/22/2023]
Abstract
The mechanisms mediating arterial stiffening with aging and menopause are not completely understood. We determined whether administration of tetrahydrobiopterin (BH(4)), a critical cofactor for endothelial nitric oxide synthase to produce nitric oxide, would increase vascular endothelial-dependent vasodilatory tone and decrease arterial stiffness in estrogen-deficient postmenopausal women. Additionally, we examined whether the beneficial effects of estrogen on vascular function were possibly related to BH(4). Arterial stiffness (carotid artery compliance) and endothelial-dependent vasodilation [brachial artery flow-mediated dilation (FMD)] were measured in postmenopausal (n = 24; 57 ± 1 yr, mean ± SE) and eumenorrheic premenopausal (n = 9; 33 ± 2 yr) women before and 3 h after the oral administration of BH(4). Subsequently, in postmenopausal women, vascular testing (before and after BH(4)) was repeated following randomization to either 2 days of transdermal estradiol or placebo. Baseline carotid artery compliance and brachial artery FMD were lower in postmenopausal than in premenopausal women (P < 0.0001). BH(4) administration increased carotid artery compliance (0.61 ± 0.05 to 0.73 ± 0.04 mm(2)·mmHg(-1)·10(-1) vs. baseline, P < 0.0001) and brachial artery FMD (P < 0.001) in postmenopausal women but had no effect in premenopausal women (P = 0.62). Carotid artery compliance (0.59 ± 0.05 to 0.78 ± 0.06 mm(2)·mmHg(-1)·10(-1), P < 0.001) and FMD increased in postmenopausal women in response to estradiol (P = 0.02) but were not further improved with the coadministration of BH(4), possibly because estrogen increased BH(4) bioavailability. Carotid artery compliance and FMD increased with BH(4) in the placebo group (P = 0.02). Although speculative, these results suggest that reduced vascular BH(4) may be an important contributor to arterial stiffening in estrogen-deficient postmenopausal women, related in part to reduced endothelial-dependent vasodilatory tone.
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Affiliation(s)
- Kerrie L Moreau
- Divisions of Geriatric Medicine, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado.
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Poole DC, Hirai DM, Copp SW, Musch TI. Muscle oxygen transport and utilization in heart failure: implications for exercise (in)tolerance. Am J Physiol Heart Circ Physiol 2012; 302:H1050-63. [PMID: 22101528 PMCID: PMC3311454 DOI: 10.1152/ajpheart.00943.2011] [Citation(s) in RCA: 206] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Accepted: 11/17/2011] [Indexed: 01/01/2023]
Abstract
The defining characteristic of chronic heart failure (CHF) is an exercise intolerance that is inextricably linked to structural and functional aberrations in the O(2) transport pathway. CHF reduces muscle O(2) supply while simultaneously increasing O(2) demands. CHF severity varies from moderate to severe and is assessed commonly in terms of the maximum O(2) uptake, which relates closely to patient morbidity and mortality in CHF and forms the basis for Weber and colleagues' (167) classifications of heart failure, speed of the O(2) uptake kinetics following exercise onset and during recovery, and the capacity to perform submaximal exercise. As the heart fails, cardiovascular regulation shifts from controlling cardiac output as a means for supplying the oxidative energetic needs of exercising skeletal muscle and other organs to preventing catastrophic swings in blood pressure. This shift is mediated by a complex array of events that include altered reflex and humoral control of the circulation, required to prevent the skeletal muscle "sleeping giant" from outstripping the pathologically limited cardiac output and secondarily impacts lung (and respiratory muscle), vascular, and locomotory muscle function. Recently, interest has also focused on the dysregulation of inflammatory mediators including tumor necrosis factor-α and interleukin-1β as well as reactive oxygen species as mediators of systemic and muscle dysfunction. This brief review focuses on skeletal muscle to address the mechanistic bases for the reduced maximum O(2) uptake, slowed O(2) uptake kinetics, and exercise intolerance in CHF. Experimental evidence in humans and animal models of CHF unveils the microvascular cause(s) and consequences of the O(2) supply (decreased)/O(2) demand (increased) imbalance emblematic of CHF. Therapeutic strategies to improve muscle microvascular and oxidative function (e.g., exercise training and anti-inflammatory, antioxidant strategies, in particular) and hence patient exercise tolerance and quality of life are presented within their appropriate context of the O(2) transport pathway.
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Affiliation(s)
- David C Poole
- Departments of Anatomy and Physiology, and Kinesiology, Kansas State University, Manhattan, KS 66506-5802, USA.
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Olmez I, Ozyurt H. Reactive oxygen species and ischemic cerebrovascular disease. Neurochem Int 2011; 60:208-12. [PMID: 22122807 DOI: 10.1016/j.neuint.2011.11.009] [Citation(s) in RCA: 205] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Revised: 09/25/2011] [Accepted: 11/12/2011] [Indexed: 02/07/2023]
Abstract
Stroke is an emerging major health problem often resulting in death or disability. Hyperlipidemia, high blood pressure and diabetes are well established risk factors. Endothelial dysfunction associated with these risk factors underlies pathological processes leading to atherogenesis and cerebral ischemic injury. While mechanisms of disease are complex, endothelial dysfunction involves decreased nitric oxide (NO) and elevated levels of reactive oxygen species (ROS). At physiological levels, ROS participate in regulation of cellular metabolism. However, when ROS increase to toxic levels through imbalance of production and neutralization by antioxidant enzymes, they cause cellular injury in the form of lipid peroxidation, protein oxidation and DNA damage. Central nervous system cells are more vulnerable to ROS toxicity due to their inherent higher oxidative metabolism and less antioxidant enzymes, as well as higher content of membranous fatty acids. During ischemic stroke, ROS concentration rises from normal low levels to a peak point during reperfusion possibly underlying apoptosis or cellular necrosis. Clinical trials and animal studies have shown that natural compounds can reduce oxidative stress due to excessive ROS through their antioxidant properties. With further study, we may be able to incorporate these compounds into clinical use with potential efficacy for both the treatment and prevention of stroke.
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Affiliation(s)
- Inan Olmez
- Vanderbilt University, Department of Neurology, Nashville, TN 37232, USA.
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PPAR-α Agonist Fenofibrate Upregulates Tetrahydrobiopterin Level through Increasing the Expression of Guanosine 5'-Triphosphate Cyclohydrolase-I in Human Umbilical Vein Endothelial Cells. PPAR Res 2011; 2011:523520. [PMID: 22190909 PMCID: PMC3236356 DOI: 10.1155/2011/523520] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 08/04/2011] [Accepted: 09/04/2011] [Indexed: 11/17/2022] Open
Abstract
Tetrahydrobiopterin (BH4) is an essential cofactor for endothelial nitric oxide (NO) synthase. Guanosine 5'-triphosphate cyclohydrolase-I (GTPCH-I) is a key limiting enzyme for BH4 synthesis. In the present in vitro study, we investigated whether peroxisome proliferator-activated receptor α (PPAR-α) agonist fenofibrate could recouple eNOS by reversing low-expression of intracellular BH4 in endothelial cells and discussed the potential mechanisms. After human umbilical vein endothelial cells (HUVECs) were treated with lipopolysaccharide (LPS) for 24 hours, the levels of cellular eNOS, BH4 and cell supernatant NO were significantly reduced compared to control group. And the fluorescence intensity of intracellular ROS was significantly increased. But pretreated with fenofibrate (10 umol/L) for 2 hours before cells were induced by LPS, the levels of eNOS, NO, and BH4 were significantly raised compared to LPS treatment alone. ROS production was markedly reduced in fenofibrate group than LPS group. In addition, our results showed that the level of intracellular GTPCH-I detected by western blot was increased in a concentration-dependent manner after being treated with fenofibrate. These results suggested that fenofibrate might help protect endothelial function and against atherosclerosis by increasing level of BH4 and decreasing production of ROS through upregulating the level of intracellular GTPCH-I.
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