1
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Hara S, Kono H, Suto N, Kojima H, Kishimoto K, Yoshino H, Niiyama S, Kakihana Y, Ichinose H. Inhibition of QDPR synergistically modulates intracellular tetrahydrobiopterin profiles in cooperation with methotrexate. Biochem Biophys Res Commun 2024; 717:150059. [PMID: 38723517 DOI: 10.1016/j.bbrc.2024.150059] [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: 01/25/2024] [Revised: 04/22/2024] [Accepted: 05/04/2024] [Indexed: 05/21/2024]
Abstract
Tetrahydrobiopterin (BH4) is an essential cofactor for dopamine and serotonin synthesis in monoaminergic neurons, phenylalanine metabolism in hepatocytes, and nitric oxide synthesis in endothelial and immune cells. BH4 is consumed as a cofactor or is readily oxidized by autooxidation. Quinonoid dihydropteridine reductase (QDPR) is an enzyme that reduces quinonoid dihydrobiopterin (qBH2) back to BH4, and we have previously demonstrated the significance of QDPR in maintaining BH4 in vivo using Qdpr-KO mice. In addition to the levels of BH4 in the cells, the ratios of oxidized to reduced forms of BH4 are supposed to be important for regulating nitric oxide synthase (NOS) via the so-called uncoupling of NOS. However, previous studies were limited due to the absence of specific and high-affinity inhibitors against QDPR. Here, we performed a high-throughput screening for a QDPR inhibitor and identified Compound 9b with an IC50 of 0.72 μM. To understand the inhibition mechanism, we performed kinetic analyses and molecular dynamics simulations. Treatment with 9b combined with methotrexate (MTX), an inhibitor of another BH4-reducing enzyme, dihydrofolate reductase (DHFR), significantly oxidized intracellular redox states in HepG2, Jurkat, SH-SY5Y, and PC12D cells. Collectively, these findings suggest that 9b may enhance the anticancer and anti-autoimmune effects of MTX.
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Affiliation(s)
- Satoshi Hara
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan; Department of Emergency and Intensive Care Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
| | - Haruka Kono
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Naoki Suto
- Drug Discovery Initiative, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Hirotatsu Kojima
- Drug Discovery Initiative, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Kaito Kishimoto
- Research and Development Center, SHIRATORI Pharmaceutical Co., Ltd, Narashino, Japan
| | - Hiroshi Yoshino
- Research and Development Center, SHIRATORI Pharmaceutical Co., Ltd, Narashino, Japan
| | - Shuhei Niiyama
- Department of Emergency and Intensive Care Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Yasuyuki Kakihana
- Department of Emergency and Intensive Care Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan
| | - Hiroshi Ichinose
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan.
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2
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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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3
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Feng Y, Feng Y, Gu L, Mo W, Wang X, Song B, Hong M, Geng F, Huang P, Yang H, Zhu W, Jiao Y, Zhang Q, Ding WQ, Cao J, Zhang S. Tetrahydrobiopterin metabolism attenuates ROS generation and radiosensitivity through LDHA S-nitrosylation: novel insight into radiogenic lung injury. Exp Mol Med 2024; 56:1107-1122. [PMID: 38689083 PMCID: PMC11148139 DOI: 10.1038/s12276-024-01208-z] [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: 08/05/2023] [Revised: 02/06/2024] [Accepted: 02/07/2024] [Indexed: 05/02/2024] Open
Abstract
Genotoxic therapy triggers reactive oxygen species (ROS) production and oxidative tissue injury. S-nitrosylation is a selective and reversible posttranslational modification of protein thiols by nitric oxide (NO), and 5,6,7,8-tetrahydrobiopterin (BH4) is an essential cofactor for NO synthesis. However, the mechanism by which BH4 affects protein S-nitrosylation and ROS generation has not been determined. Here, we showed that ionizing radiation disrupted the structural integrity of BH4 and downregulated GTP cyclohydrolase I (GCH1), which is the rate-limiting enzyme in BH4 biosynthesis, resulting in deficiency in overall protein S-nitrosylation. GCH1-mediated BH4 synthesis significantly reduced radiation-induced ROS production and fueled the global protein S-nitrosylation that was disrupted by radiation. Likewise, GCH1 overexpression or the administration of exogenous BH4 protected against radiation-induced oxidative injury in vitro and in vivo. Conditional pulmonary Gch1 knockout in mice (Gch1fl/fl; Sftpa1-Cre+/- mice) aggravated lung injury following irradiation, whereas Gch1 knock-in mice (Gch1lsl/lsl; Sftpa1-Cre+/- mice) exhibited attenuated radiation-induced pulmonary toxicity. Mechanistically, lactate dehydrogenase (LDHA) mediated ROS generation downstream of the BH4/NO axis, as determined by iodoacetyl tandem mass tag (iodoTMT)-based protein quantification. Notably, S-nitrosylation of LDHA at Cys163 and Cys293 was regulated by BH4 availability and could restrict ROS generation. The loss of S-nitrosylation in LDHA after irradiation increased radiosensitivity. Overall, the results of the present study showed that GCH1-mediated BH4 biosynthesis played a key role in the ROS cascade and radiosensitivity through LDHA S-nitrosylation, identifying novel therapeutic strategies for the treatment of radiation-induced lung injury.
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Affiliation(s)
- Yang Feng
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, 215123, Suzhou, China
- Department of Oncology, Wuxi No.2 People's Hospital, Jiangnan University Medical Center, 214002, Wuxi, China
| | - Yahui Feng
- Laboratory of Radiation Medicine, Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital, 610051, Chengdu, China
| | - Liming Gu
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, 215123, Suzhou, China
| | - Wei Mo
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, 215123, Suzhou, China
| | - Xi Wang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, 215123, Suzhou, China
| | - Bin Song
- West China Second University Hospital, Sichuan University, 610041, Chengdu, China
| | - Min Hong
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, 215123, Suzhou, China
| | - Fenghao Geng
- West China Second University Hospital, Sichuan University, 610041, Chengdu, China
| | - Pei Huang
- Department of Oncology, Wuxi No.2 People's Hospital, Jiangnan University Medical Center, 214002, Wuxi, China
| | - Hongying Yang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, 215123, Suzhou, China
| | - Wei Zhu
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, 215123, Suzhou, China
| | - Yang Jiao
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, 215123, Suzhou, China
| | - Qi Zhang
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, 215123, Suzhou, China
| | - Wei-Qun Ding
- Department of Pathology, Stephenson Cancer Centre, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Jianping Cao
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Medical College of Soochow University, 215123, Suzhou, China.
| | - Shuyu Zhang
- Laboratory of Radiation Medicine, Second Affiliated Hospital of Chengdu Medical College, China National Nuclear Corporation 416 Hospital, 610051, Chengdu, China.
- West China Second University Hospital, Sichuan University, 610041, Chengdu, China.
- Laboratory of Radiation Medicine, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, 610041, Chengdu, China.
- NHC Key Laboratory of Nuclear Technology Medical Transformation (Mianyang Central Hospital), 621099, Mianyang, China.
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Clark GC, Lai A, Agarwal A, Liu Z, Wang XY. Biopterin metabolism and nitric oxide recoupling in cancer. Front Oncol 2024; 13:1321326. [PMID: 38469569 PMCID: PMC10925643 DOI: 10.3389/fonc.2023.1321326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/26/2023] [Indexed: 03/13/2024] Open
Abstract
Tetrahydrobiopterin is a cofactor necessary for the activity of several enzymes, the most studied of which is nitric oxide synthase. The role of this cofactor-enzyme relationship in vascular biology is well established. Recently, tetrahydrobiopterin metabolism has received increasing attention in the field of cancer immunology and immunotherapy due to its involvement in the cytotoxic T cell response. Past research has demonstrated that when the availability of BH4 is low, as it is in chronic inflammatory conditions and tumors, electron transfer in the active site of nitric oxide synthase becomes uncoupled from the oxidation of arginine. This results in the production of radical species that are capable of a direct attack on tetrahydrobiopterin, further depleting its local availability. This feedforward loop may act like a molecular switch, reinforcing low tetrahydrobiopterin levels leading to altered NO signaling, restrained immune effector activity, and perpetual vascular inflammation within the tumor microenvironment. In this review, we discuss the evidence for this underappreciated mechanism in different aspects of tumor progression and therapeutic responses. Furthermore, we discuss the preclinical evidence supporting a clinical role for tetrahydrobiopterin supplementation to enhance immunotherapy and radiotherapy for solid tumors and the potential safety concerns.
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Affiliation(s)
- Gene Chatman Clark
- Department of Biochemistry, Virginia Commonwealth University, Richmond, VA, United States
- School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Alan Lai
- School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | | | - Zheng Liu
- Department of Human Molecular Genetics, Virginia Commonwealth University, Richmond, VA, United States
- Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, United States
| | - Xiang-Yang Wang
- Department of Human Molecular Genetics, Virginia Commonwealth University, Richmond, VA, United States
- Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, United States
- Institute of Molecular Medicine, Virginia Commonwealth University, Richmond, VA, United States
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5
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Caminiti R, Carresi C, Mollace R, Macrì R, Scarano F, Oppedisano F, Maiuolo J, Serra M, Ruga S, Nucera S, Tavernese A, Gliozzi M, Musolino V, Palma E, Muscoli C, Rubattu S, Volterrani M, Federici M, Volpe M, Mollace V. The potential effect of natural antioxidants on endothelial dysfunction associated with arterial hypertension. Front Cardiovasc Med 2024; 11:1345218. [PMID: 38370153 PMCID: PMC10869541 DOI: 10.3389/fcvm.2024.1345218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 01/15/2024] [Indexed: 02/20/2024] Open
Abstract
Arterial hypertension represents a leading cause of cardiovascular morbidity and mortality worldwide, and the identification of effective solutions for treating the early stages of elevated blood pressure (BP) is still a relevant issue for cardiovascular risk prevention. The pathophysiological basis for the occurrence of elevated BP and the onset of arterial hypertension have been widely studied in recent years. In addition, consistent progress in the development of novel, powerful, antihypertensive drugs and their appropriate applications in controlling BP have increased our potential for successfully managing disease states characterized by abnormal blood pressure. However, the mechanisms responsible for the disruption of endogenous mechanisms contributing to the maintenance of BP within a normal range are yet to be fully clarified. Recently, evidence has shown that several natural antioxidants containing active ingredients originating from natural plant extracts, used alone or in combination, may represent a valid solution for counteracting the development of arterial hypertension. In particular, there is evidence to show that natural antioxidants may enhance the viability of endothelial cells undergoing oxidative damage, an effect that could play a crucial role in the pathophysiological events accompanying the early stages of arterial hypertension. The present review aims to reassess the role of oxidative stress on endothelial dysfunction in the onset and progression of arterial hypertension and that of natural antioxidants in covering several unmet needs in the treatment of such diseases.
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Affiliation(s)
- Rosamaria Caminiti
- Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Cristina Carresi
- Department of Health Sciences, Veterinary Pharmacology Laboratory, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Rocco Mollace
- Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
- Department of Systems Medicine, University “Tor Vergata” of Rome, Rome, Italy
| | - Roberta Macrì
- Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Federica Scarano
- Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Francesca Oppedisano
- Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Jessica Maiuolo
- Laboratory of Pharmaceutical Biology, Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Maria Serra
- Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Stefano Ruga
- Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Saverio Nucera
- Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Annamaria Tavernese
- Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Micaela Gliozzi
- Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Vincenzo Musolino
- Laboratory of Pharmaceutical Biology, Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Ernesto Palma
- Department of Health Sciences, Veterinary Pharmacology Laboratory, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
| | - Carolina Muscoli
- Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
- IRCCS San Raffaele Roma, Rome, Italy
| | - Speranza Rubattu
- IRCCS Neuromed, Pozzilli, Italy
- Department of Clinical and Molecular Medicine, School of Medicine and Psychology, Sapienza University, Rome, Italy
| | | | - Massimo Federici
- Department of Systems Medicine, University “Tor Vergata” of Rome, Rome, Italy
| | | | - Vincenzo Mollace
- Department of Health Sciences, Institute of Research for Food Safety and Health (IRC-FSH), University “Magna Graecia” of Catanzaro, Catanzaro, Italy
- Renato Dulbecco Institute, Catanzaro, Italy
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6
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Fasipe B, Li S, Laher I. Exercise and vascular function in sedentary lifestyles in humans. Pflugers Arch 2023:10.1007/s00424-023-02828-6. [PMID: 37272982 DOI: 10.1007/s00424-023-02828-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 05/30/2023] [Accepted: 05/31/2023] [Indexed: 06/06/2023]
Abstract
People with sedentary lifestyles engage in minimal or no physical activity. A sedentary lifestyle promotes dysregulation of cellular redox balance, diminishes mitochondrial function, and increases NADPH oxidase activity. These changes collectively increase cellular oxidative stress, which alters endothelial function by oxidizing LDL-C, reducing NO production, and causing eNOS uncoupling. Reduced levels of nitric oxide (NO) leads to vasoconstriction, vascular remodeling, and vascular inflammation. Exercise modulates reactive oxygen species (ROS) to modify NRF2-KEAP signaling, leading to the activation of NRF2 to alleviate oxidative stress. While regular moderate exercise activates NRF2 through ROS production, high-intensity intermittent exercise stimulates NRF2 activation to a greater degree by reducing KEAP levels, which can be more beneficial for sedentary individuals. We review the damaging effects of a sedentary lifestyle on the vascular system and the health benefits of regular and intermittent exercise.
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Affiliation(s)
- Babatunde Fasipe
- Faculty of Basic Clinical Sciences, Department of Pharmacology and Therapeutics, Bowen University, Iwo, Nigeria
| | - Shunchang Li
- Institute of Sports Medicine and Health, Chengdu Sport University, Chengdu, 610041, China
| | - Ismail Laher
- Faculty of Medicine, Department of Anesthesiology, Pharmacology and Therapeutics, The University of British Columbia, 2176 Health Sciences Mall, Vancouver, Canada.
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7
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Wahlstrøm KL, Hansen HF, Kvist M, Burcharth J, Lykkesfeldt J, Gögenur I, Ekeloef S. Effect of Remote Ischaemic Preconditioning on Perioperative Endothelial Dysfunction in Non-Cardiac Surgery: A Randomised Clinical Trial. Cells 2023; 12:cells12060911. [PMID: 36980253 PMCID: PMC10047371 DOI: 10.3390/cells12060911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 02/24/2023] [Accepted: 03/11/2023] [Indexed: 03/18/2023] Open
Abstract
Endothelial dysfunction result from inflammation and excessive production of reactive oxygen species as part of the surgical stress response. Remote ischemic preconditioning (RIPC) potentially exerts anti-oxidative and anti-inflammatory properties, which might stabilise the endothelial function after non-cardiac surgery. This was a single centre randomised clinical trial including 60 patients undergoing sub-acute laparoscopic cholecystectomy due to acute cholecystitis. Patients were randomised to RIPC or control. The RIPC procedure consisted of four cycles of five minutes of ischaemia and reperfusion of one upper extremity. Endothelial function was assessed as the reactive hyperaemia index (RHI) and circulating biomarkers of nitric oxide (NO) bioavailability (L-arginine, asymmetric dimethylarginine (ADMA), L-arginine/ADMA ratio, tetra- and dihydrobiopterin (BH4 and BH2), and total plasma biopterin) preoperative, 2–4 h after surgery and 24 h after surgery. RHI did not differ between the groups (p = 0.07). Neither did levels of circulating biomarkers of NO bioavailability change in response to RIPC. L-arginine and L-arginine/ADMA ratio was suppressed preoperatively and increased 24 h after surgery (p < 0.001). The BH4/BH2-ratio had a high preoperative level, decreased 2–4 h after surgery and remained low 24 h after surgery (p = 0.01). RIPC did not influence endothelial function or markers of NO bioavailability until 24 h after sub-acute laparoscopic cholecystectomy. In response to surgery, markers of NO bioavailability increased, and oxidative stress decreased. These findings support that a minimally invasive removal of the inflamed gallbladder countereffects reduced markers of NO bioavailability and increased oxidative stress caused by acute cholecystitis.
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Affiliation(s)
- Kirsten L. Wahlstrøm
- Center for Surgical Science, Department of Surgery, Zealand University Hospital, Lykkebækvej 1, 4600 Køge, Denmark
- Correspondence:
| | - Hannah F. Hansen
- Center for Surgical Science, Department of Surgery, Zealand University Hospital, Lykkebækvej 1, 4600 Køge, Denmark
| | - Madeline Kvist
- Center for Surgical Science, Department of Surgery, Zealand University Hospital, Lykkebækvej 1, 4600 Køge, Denmark
| | - Jakob Burcharth
- Center for Surgical Science, Department of Surgery, Zealand University Hospital, Lykkebækvej 1, 4600 Køge, Denmark
| | - Jens Lykkesfeldt
- Section of Experimental Animal Models, Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Ridebanevej 9, 1871 Frederiksberg C, Denmark
| | - Ismail Gögenur
- Center for Surgical Science, Department of Surgery, Zealand University Hospital, Lykkebækvej 1, 4600 Køge, Denmark
- Department of Clinical Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Sarah Ekeloef
- Center for Surgical Science, Department of Surgery, Zealand University Hospital, Lykkebækvej 1, 4600 Køge, Denmark
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8
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Alam A, Smith SC, Gobalakrishnan S, McGinn M, Yakovlev VA, Rabender CS. Uncoupled nitric oxide synthase activity promotes colorectal cancer progression. Front Oncol 2023; 13:1165326. [PMID: 36998441 PMCID: PMC10046306 DOI: 10.3389/fonc.2023.1165326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 02/24/2023] [Indexed: 03/16/2023] Open
Abstract
Increased levels of reactive oxygen/nitrogen species are one hallmark of chronic inflammation contributing to the activation of pro-inflammatory/proliferative pathways. In the cancers analyzed, the tetrahydrobiopterin:dihydrobiopterin ratio is lower than that of the corresponding normal tissue, leading to an uncoupled nitric oxide synthase activity and increased generation of reactive oxygen/nitrogen species. Previously, we demonstrated that prophylactic treatment with sepiapterin, a salvage pathway precursor of tetrahydrobiopterin, prevents dextran sodium sulfate-induced colitis in mice and associated azoxymethane-induced colorectal cancer. Herein, we report that increasing the tetrahydrobiopterin:dihydrobiopterin ratio and recoupling nitric oxide synthase with sepiapterin in the colon cancer cell lines, HCT116 and HT29, inhibit their proliferation and enhance cell death, in part, by Akt/GSK-3β-mediated downregulation of β-catenin. Therapeutic oral gavage with sepiapterin of mice bearing azoxymethane/dextran sodium sulfate-induced colorectal cancer decreased metabolic uptake of [18F]-fluorodeoxyglucose and enhanced apoptosis nine-fold in these tumors. Immunohistochemical analysis of both mouse and human tissues indicated downregulated expression of key enzymes in tetrahydrobiopterin biosynthesis in the colorectal cancer tumors. Human stage 1 colon tumors exhibited a significant decrease in the expression of quinoid dihydropteridine reductase, a key enzyme involved in recycling tetrahydrobiopterin suggesting a potential mechanism for the reduced tetrahydrobiopterin:dihydrobiopterin ratio in these tumors. In summary, sepiapterin treatment of colorectal cancer cells increases the tetrahydrobiopterin:dihydrobiopterin ratio, recouples nitric oxide synthase, and reduces tumor growth. We conclude that nitric oxide synthase coupling may provide a useful therapeutic target for treating patients with colorectal cancer.
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Affiliation(s)
- Asim Alam
- Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA, United States
| | - Steven C. Smith
- Department of Pathology, Virginia Commonwealth University, Richmond, VA, United States
| | | | - Mina McGinn
- Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA, United States
| | - Vasily A. Yakovlev
- Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA, United States
| | - Christopher S. Rabender
- Department of Radiation Oncology, Virginia Commonwealth University, Richmond, VA, United States
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9
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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: 30] [Impact Index Per Article: 30.0] [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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10
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Madokoro Y, Kamikokuryo C, Niiyama S, Ito T, Hara S, Ichinose H, Kakihana Y. Early ascorbic acid administration prevents vascular endothelial cell damage in septic mice. Front Pharmacol 2022; 13:929448. [PMID: 36278212 PMCID: PMC9582851 DOI: 10.3389/fphar.2022.929448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 09/21/2022] [Indexed: 11/13/2022] Open
Abstract
Oxidation of BH4, a cofactor of nitric oxide synthase (NOS), produces reactive oxygen species (ROS) through uncoupling of NOS and affects vascular endothelial dysfunction. Ascorbic acid (AsA) inhibits the oxidation of BH4 and reduces ROS. However, the kinetic changes of BH4 in sepsis and its effect on the kinetic changes in AsA administration therapy, as well as the appropriate timing of AsA administration for AsA therapy to be effective, are unclear. Mice with sepsis, induced by cecal ligation and puncture (CLP), were examined for the effect of AsA administration (200 mg/kg) on vascular endothelial cell dysfunction at two administration timings: early group (AsA administered immediately after CLP) and late group (AsA administered 12 h after CLP). Survival rates were compared between the early and late administration groups, and vascular endothelial cell damage, indicated by the dihydrobiopterin/tetrahydrobiopterin ratio, serum syndecan-1, and endothelial nitric oxide synthase, as well as liver damage, were examined. The early group showed significantly improved survival compared to the non-treatment group (p < 0.05), while the late group showed no improved survival compared to the non-treatment group. Compared to the non-treated group, the early AsA group showed less oxidation of BH4 in sepsis. Syndecan1, a marker of vascular endothelial cell damage, was less elevated and organ damage was reduced in the early AsA-treated group. In septic mice, early AsA administration immediately after CLP may protect vascular endothelial cells by inhibiting BH4 oxidation, thereby reducing organ dysfunction and improving survival.
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Affiliation(s)
- Yutaro Madokoro
- Department of Emergency and Intensive Care Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Chinatsu Kamikokuryo
- Department of Emergency and Intensive Care Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Shuhei Niiyama
- Department of Emergency and Intensive Care Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Takashi Ito
- Department of Biomedical Laboratory Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Satoshi Hara
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Hiroshi Ichinose
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Yasuyuki Kakihana
- Department of Emergency and Intensive Care Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
- *Correspondence: Yasuyuki Kakihana,
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11
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Measurement of Tetrahydrobiopterin in Animal Tissue Samples by HPLC with Electrochemical Detection-Protocol Optimization and Pitfalls. Antioxidants (Basel) 2022; 11:antiox11061182. [PMID: 35740082 PMCID: PMC9228106 DOI: 10.3390/antiox11061182] [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: 06/03/2022] [Revised: 06/10/2022] [Accepted: 06/14/2022] [Indexed: 11/17/2022] Open
Abstract
Tetrahydrobiopterin (BH4) is an essential cofactor of all nitric oxide synthase isoforms, thus determination of BH4 levels can provide important mechanistic insight into diseases. We established a protocol for high-performance liquid chromatography/electrochemical detection (HPLC/ECD)-based determination of BH4 in tissue samples. We first determined the optimal storage and work-up conditions for authentic BH4 and its oxidation product dihydrobiopterin (BH2) under various conditions (pH, temperature, presence of antioxidants, metal chelators, and storage time). We then applied optimized protocols for detection of BH4 in tissues of septic (induced by lipopolysaccharide [LPS]) rats. BH4 standards in HCl are stabilized by addition of 1,4-dithioerythritol (DTE) and diethylenetriaminepentaacetic acid (DTPA), while HCl was sufficient for BH2 standard stabilization. Overnight storage of BH4 standard solutions at room temperature in HCl without antioxidants caused complete loss of BH4 and the formation of BH2. We further optimized the protocol to separate ascorbate and the BH4 tissue sample and found a significant increase in BH4 in the heart and kidney as well as higher BH4 levels by trend in the brain of septic rats compared to control rats. These findings correspond to reports on augmented nitric oxide and BH4 levels in both animals and patients with septic shock.
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12
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Piacenza L, Zeida A, Trujillo M, Radi R. The superoxide radical switch in the biology of nitric oxide and peroxynitrite. Physiol Rev 2022; 102:1881-1906. [PMID: 35605280 DOI: 10.1152/physrev.00005.2022] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Lucìa Piacenza
- Departamento de Bioquímica, Facultad de Medicina; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Uruguay
| | - Ari Zeida
- Departamento de Bioquímica, Facultad de Medicina; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay
| | - Madia Trujillo
- Departamento de Bioquímica, Facultad de Medicina; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay
| | - Rafael Radi
- Departamento de Bioquímica, Facultad de Medicina; Centro de Investigaciones Biomédicas (CEINBIO), Universidad de la República, Montevideo, Uruguay
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13
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Tran N, Garcia T, Aniqa M, Ali S, Ally A, Nauli SM. Endothelial Nitric Oxide Synthase (eNOS) and the Cardiovascular System: in Physiology and in Disease States. AMERICAN JOURNAL OF BIOMEDICAL SCIENCE & RESEARCH 2022; 15:153-177. [PMID: 35072089 PMCID: PMC8774925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Endothelial nitric oxide synthase (eNOS) plays a critical role in regulating and maintaining a healthy cardiovascular system. The importance of eNOS can be emphasized from the genetic polymorphisms of the eNOS gene, uncoupling of eNOS dimerization, and its numerous signaling regulations. The activity of eNOS on the cardiac myocytes, vasculature, and the central nervous system are discussed. The effects of eNOS on the sympathetic autonomic nervous system (SANS) and the parasympathetic autonomic nervous system (PANS), both of which profoundly influence the cardiovascular system, will be elaborated. The relationship between the eNOS protein with cardiovascular autonomic reflexes such as the baroreflex and the Exercise Pressor Reflex will be discussed. For example, the effects of endogenous nitric oxide (NO) are shown to be mediated by the eNOS protein and that eNOS-derived endothelial NO is most effective in regulating blood pressure oscillations via modulating the baroreflex mechanisms. The protective action of eNOS on the CVS is emphasized here because dysfunction of the eNOS enzyme is intricately correlated with the pathogenesis of several cardiovascular diseases such as hypertension, arteriosclerosis, myocardial infarction, and stroke. Overall, our current understanding of the eNOS protein with a focus on its role in the modulation, regulation, and control of the cardiovascular system in a normal physiological state and in cardiovascular diseases are discussed.
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Affiliation(s)
- N Tran
- Arkansas College of Osteopathic Medicine, Fort Smith, AR, USA
| | - T Garcia
- Arkansas College of Osteopathic Medicine, Fort Smith, AR, USA
| | - M Aniqa
- Arkansas College of Osteopathic Medicine, Fort Smith, AR, USA
| | - S Ali
- Arkansas College of Osteopathic Medicine, Fort Smith, AR, USA
| | - A Ally
- Arkansas College of Osteopathic Medicine, Fort Smith, AR, USA,Corresponding author: Surya M Nauli, Chapman University and University of California, Irvine, CA, USA
| | - SM Nauli
- Chapman University and University of California, Irvine, CA, USA,Corresponding author: Surya M Nauli, Chapman University and University of California, Irvine, CA, USA
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14
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Bouly M, Bourguignon MP, Roesch S, Rigouin P, Gosgnach W, Bossard E, Royere E, Diguet N, Sansilvestri-Morel P, Bonnin A, Xuereb L, Berson P, Komajda M, Bernhardt P, Tyl B. Aging increases circulating BH 2 without modifying BH 4 levels and impairs peripheral vascular function in healthy adults. Transl Res 2021; 238:36-48. [PMID: 34332154 DOI: 10.1016/j.trsl.2021.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/23/2021] [Accepted: 07/23/2021] [Indexed: 11/17/2022]
Abstract
Little is known about the mechanisms of aging on vascular beds and its relationship with tetra and di-hydrobiopterin (BH4 and BH2) levels. This observational clinical study analyzed the impact of aging on plasma and platelet biopterins, cutaneous blood flow (CBF), and coronary flow reserve (CFR) in healthy adults. The study enrolled healthy adults in 3 age groups: 18-30, 50-59, and 60-70 years (n = 25/group). Biopterins were assessed by LC-MS/MS using newly defined pre-analytical conditions limiting BH4 oxidation and improving long-term stability. CBF was measured by Laser Speckle Contrast Imaging coupled with acetylcholine-iontophoresis and CFR by adenosine stress cardiac magnetic resonance. In healthy adults, aging (60-70 years vs 18-30 years) significantly increased platelet BH2 (+75%, P = 0.033) and BH2 + BH4 (+31%, P = 0.033), and to a lesser extent plasma BH2 (+29%, P = 0.009) without affecting BH4 and BH4/BH2. Simultaneously, CBF was decreased (-23%, P = 0.004) but not CFR, CBF being inversely correlated with platelet BH2 (r = -0.42, P = 0.001) and BH2 + BH4 (r = -0.41, P = 0.002). The proportion of adults with abnormal platelet BH2 increased with age (+28% in 60-70y). These abnormal BH2 levels were significantly associated with reduced CBF and CFR (-16%, P = 0.03 and -26%, P = 0.02). In conclusion, our study showed that age-related peripheral endothelial dysfunction was associated with an increase in circulating BH2 without decreasing BH4, the effect being more marked in platelets, the most relevant blood compartment to assess biopterin bioavailability. Peripheral but not coronary vascular function is progressively impaired with aging in healthy adults. All these findings support biopterins as therapeutic targets to improve vascular function.
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Affiliation(s)
- Muriel Bouly
- Cardiovascular & Metabolic Disease Centre for Therapeutic Innovation, Institut de Recherches Internationales Servier, Suresnes, France
| | - Marie-Pierre Bourguignon
- Cardiovascular & Metabolic Disease Centre for Therapeutic Innovation, Institut de Recherches Servier, Suresnes, France
| | - Susanne Roesch
- Centre of Excellence Clinical Operations, Institut de Recherches Internationales Servier, Suresnes, France
| | - Pascal Rigouin
- Biostatistics Department, Keyrus Life Science, Nantes, France
| | - Willy Gosgnach
- Centre of Excellence Biotechnology, Institut de Recherches Servier, Croissy, France
| | | | - Emilie Royere
- Cardiovascular & Metabolic Disease Centre for Therapeutic Innovation, Institut de Recherches Servier, Suresnes, France
| | - Nicolas Diguet
- Cardiovascular & Metabolic Disease Centre for Therapeutic Innovation, Institut de Recherches Servier, Suresnes, France
| | - Patricia Sansilvestri-Morel
- Cardiovascular & Metabolic Disease Centre for Therapeutic Innovation, Institut de Recherches Servier, Suresnes, France
| | - Ariane Bonnin
- Drug Safety & Pharmacokinetics Centre of Excellence, Biologie Servier, Gidy, France
| | - Laura Xuereb
- Centre of Excellence Methodology and Valorisation of Data, Institut de Recherches Internationales Servier, Suresnes, France
| | - Pascal Berson
- Cardiovascular & Metabolic Disease Centre for Therapeutic Innovation, Institut de Recherches Servier, Suresnes, France
| | - Michel Komajda
- Department of Cardiology, Hospital Saint Joseph, France/Paris Sorbonne Université France, Paris, France
| | | | - Benoit Tyl
- Cardiovascular & Metabolic Disease Centre for Therapeutic Innovation, Institut de Recherches Internationales Servier, Suresnes, France
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15
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Rubach MP, Mukemba JP, Florence SM, Lopansri BK, Hyland K, Simmons RA, Langelier C, Nakielny S, DeRisi JL, Yeo TW, Anstey NM, Weinberg JB, Mwaikambo ED, Granger DL. Cerebrospinal Fluid Pterins, Pterin-Dependent Neurotransmitters, and Mortality in Pediatric Cerebral Malaria. J Infect Dis 2021; 224:1432-1441. [PMID: 33617646 PMCID: PMC8682765 DOI: 10.1093/infdis/jiab086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 02/10/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Cerebral malaria (CM) pathogenesis remains incompletely understood. Having shown low systemic levels of tetrahydrobiopterin (BH4), an enzymatic cofactor for neurotransmitter synthesis, we hypothesized that BH4 and BH4-dependent neurotransmitters would likewise be low in cerebrospinal fluid (CSF) in CM. METHODS We prospectively enrolled Tanzanian children with CM and children with nonmalaria central nervous system conditions (NMCs). We measured CSF levels of BH4, neopterin, and BH4-dependent neurotransmitter metabolites, 3-O-methyldopa, homovanillic acid, and 5-hydroxyindoleacetate, and we derived age-adjusted z-scores using published reference ranges. RESULTS Cerebrospinal fluid BH4 was elevated in CM (n = 49) compared with NMC (n = 51) (z-score 0.75 vs -0.08; P < .001). Neopterin was increased in CM (z-score 4.05 vs 0.09; P < .001), and a cutoff at the upper limit of normal (60 nmol/L) was 100% sensitive for CM. Neurotransmitter metabolite levels were overall preserved. A higher CSF BH4/BH2 ratio was associated with increased odds of survival (odds ratio, 2.94; 95% confidence interval, 1.03-8.33; P = .043). CONCLUSION Despite low systemic BH4, CSF BH4 was elevated and associated with increased odds of survival in CM. Coma in malaria is not explained by deficiency of BH4-dependent neurotransmitters. Elevated CSF neopterin was 100% sensitive for CM diagnosis and warrants further assessment of its clinical utility for ruling out CM in malaria-endemic areas.
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Affiliation(s)
- Matthew P Rubach
- Department of Medicine, Division of Infectious Diseases, Duke University, Durham, North Carolina, USA
- Duke Global Health Institute, Duke University, Durham, North Carolina, USA
| | - Jackson P Mukemba
- Department of Pediatrics, Hubert Kairuki Memorial University, Dar es Salaam, United Republic of Tanzania
| | - Salvatore M Florence
- Department of Pediatrics, Hubert Kairuki Memorial University, Dar es Salaam, United Republic of Tanzania
| | - Bert K Lopansri
- Department of Medicine, Intermountain Healthcare, Salt Lake City, Utah, USA
- Department of Medicine, University of Utah School of Medicine and VA Medical Center, Salt Lake City, Utah, USA
| | - Keith Hyland
- Medical Neurogenetics Laboratories, Atlanta, Georgia, USA
| | - Ryan A Simmons
- Duke Global Health Institute, Duke University, Durham, North Carolina, USA
- Department of Biostatistics, Duke University, Durham, North Carolina, USA
| | - Charles Langelier
- Department of Medicine, Division of Infectious Diseases, University of California San Francisco, San Francisco, California, USA
- Chan Zuckerberg Biohub, San Francisco, California, USA
| | - Sara Nakielny
- Chan Zuckerberg Biohub, San Francisco, California, USA
| | - Joseph L DeRisi
- Chan Zuckerberg Biohub, San Francisco, California, USA
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA
| | - Tsin W Yeo
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Australia
- Division of Medicine, Royal Darwin Hospital, Darwin, Northern Territory, Australia
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Nicholas M Anstey
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Australia
- Division of Medicine, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - J Brice Weinberg
- Department of Medicine, Duke University and VA Medical Centers, Durham, North Carolina, USA
| | - Esther D Mwaikambo
- Department of Pediatrics, Hubert Kairuki Memorial University, Dar es Salaam, United Republic of Tanzania
| | - Donald L Granger
- Department of Medicine, University of Utah School of Medicine and VA Medical Center, Salt Lake City, Utah, USA
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16
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Feng Y, Feng Y, Gu L, Liu P, Cao J, Zhang S. The Critical Role of Tetrahydrobiopterin (BH4) Metabolism in Modulating Radiosensitivity: BH4/NOS Axis as an Angel or a Devil. Front Oncol 2021; 11:720632. [PMID: 34513700 PMCID: PMC8429800 DOI: 10.3389/fonc.2021.720632] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/12/2021] [Indexed: 12/16/2022] Open
Abstract
Ionizing radiation and radioactive materials have been widely used in industry, medicine, science and military. The efficacy of radiotherapy and adverse effects of normal tissues are closed related to cellular radiosensitivity. Molecular mechanisms underlying radiosensitivity are of significance to tumor cell radiosensitization as well as normal tissue radioprotection. 5,6,7,8-Tetrahydrobiopterin (BH4) is an essential cofactor for nitric oxide synthases (NOS) and aromatic amino acid hydroxylases, and its biosynthesis involves de novo biosynthesis and a pterin salvage pathway. In this review we overview the role of BH4 metabolism in modulating radiosensitivity. BH4 homeostasis determines the role of NOS, affecting the production of nitric oxide (NO) and oxygen free radicals. Under conditions of oxidative stress, such as UV-radiation and ionizing radiation, BH4 availability is diminished due to its oxidation, which subsequently leads to NOS uncoupling and generation of highly oxidative free radicals. On the other hand, BH4/NOS axis facilitates vascular normalization, a process by which antiangiogenic therapy corrects structural and functional flaws of tumor blood vessels, which enhances radiotherapy efficacy. Therefore, BH4/NOS axis may serve as an angel or a devil in regulating cellular radiosensitivity. Finally, we will address future perspectives, not only from the standpoint of perceived advances in treatment, but also from the potential mechanisms. These advances have demonstrated that it is possible to modulate cellular radiosensitivity through BH4 metabolism.
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Affiliation(s)
- Yang Feng
- School of Radiation Medicine and Protection, State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, China
| | - Yahui Feng
- China National Nuclear Corporation 416 Hospital (Second Affiliated Hospital of Chengdu Medical College), Chengdu, China
| | - Liming Gu
- School of Radiation Medicine and Protection, State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, China
| | - Pengfei Liu
- School of Radiation Medicine and Protection, State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, China
| | - Jianping Cao
- School of Radiation Medicine and Protection, State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, China
| | - Shuyu Zhang
- China National Nuclear Corporation 416 Hospital (Second Affiliated Hospital of Chengdu Medical College), Chengdu, China.,West China Second University Hospital, Sichuan University, Chengdu, China.,West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
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17
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de Melo FHM, Gonçalves DA, de Sousa RX, Icimoto MY, Fernandes DDC, Laurindo FRM, Jasiulionis MG. Metastatic Melanoma Progression Is Associated with Endothelial Nitric Oxide Synthase Uncoupling Induced by Loss of eNOS:BH4 Stoichiometry. Int J Mol Sci 2021; 22:9556. [PMID: 34502464 PMCID: PMC8430733 DOI: 10.3390/ijms22179556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/13/2021] [Accepted: 08/17/2021] [Indexed: 12/26/2022] Open
Abstract
Melanoma is the most aggressive type of skin cancer due to its high capability of developing metastasis and acquiring chemoresistance. Altered redox homeostasis induced by increased reactive oxygen species is associated with melanomagenesis through modulation of redox signaling pathways. Dysfunctional endothelial nitric oxide synthase (eNOS) produces superoxide anion (O2-•) and contributes to the establishment of a pro-oxidant environment in melanoma. Although decreased tetrahydrobiopterin (BH4) bioavailability is associated with eNOS uncoupling in endothelial and human melanoma cells, in the present work we show that eNOS uncoupling in metastatic melanoma cells expressing the genes from de novo biopterin synthesis pathway Gch1, Pts, and Spr, and high BH4 concentration and BH4:BH2 ratio. Western blot analysis showed increased expression of Nos3, altering the stoichiometry balance between eNOS and BH4, contributing to NOS uncoupling. Both treatment with L-sepiapterin and eNOS downregulation induced increased nitric oxide (NO) and decreased O2• levels, triggering NOS coupling and reducing cell growth and resistance to anoikis and dacarbazine chemotherapy. Moreover, restoration of eNOS activity impaired tumor growth in vivo. Finally, NOS3 expression was found to be increased in human metastatic melanoma samples compared with the primary site. eNOS dysfunction may be an important mechanism supporting metastatic melanoma growth and hence a potential target for therapy.
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Affiliation(s)
- Fabiana Henriques Machado de Melo
- Pharmacology Department, Universidade Federal de São Paulo, São Paulo 05508-090, Brazil
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo 05508-060, Brazil
| | - Diego Assis Gonçalves
- Micro-Imuno-Parasitology Department, Universidade Federal de São Paulo, São Paulo 05508-090, Brazil;
- Parasitology Department, Microbiology and Immunology, Federal University of Juiz de Fora, Juiz de Fora 36036-900, Brazil
| | - Ricardo Xisto de Sousa
- Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, São Paulo 01221-020, Brazil;
| | - Marcelo Yudi Icimoto
- Biophysics Department, Universidade Federal de São Paulo, São Paulo 05508-090, Brazil;
| | - Denise de Castro Fernandes
- Vascular Biology Laboratory, Heart Institute (InCor), University of São Paulo School of Medicine, São Paulo 05508-060, Brazil; (D.d.C.F.); (F.R.M.L.)
| | - Francisco R. M. Laurindo
- Vascular Biology Laboratory, Heart Institute (InCor), University of São Paulo School of Medicine, São Paulo 05508-060, Brazil; (D.d.C.F.); (F.R.M.L.)
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18
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Dent MR, DeMartino AW, Tejero J, Gladwin MT. Endogenous Hemoprotein-Dependent Signaling Pathways of Nitric Oxide and Nitrite. Inorg Chem 2021; 60:15918-15940. [PMID: 34313417 DOI: 10.1021/acs.inorgchem.1c01048] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Interdisciplinary research at the interface of chemistry, physiology, and biomedicine have uncovered pivotal roles of nitric oxide (NO) as a signaling molecule that regulates vascular tone, platelet aggregation, and other pathways relevant to human health and disease. Heme is central to physiological NO signaling, serving as the active site for canonical NO biosynthesis in nitric oxide synthase (NOS) enzymes and as the highly selective NO binding site in the soluble guanylyl cyclase receptor. Outside of the primary NOS-dependent biosynthetic pathway, other hemoproteins, including hemoglobin and myoglobin, generate NO via the reduction of nitrite. This auxiliary hemoprotein reaction unlocks a "second axis" of NO signaling in which nitrite serves as a stable NO reservoir. In this Forum Article, we highlight these NO-dependent physiological pathways and examine complex chemical and biochemical reactions that govern NO and nitrite signaling in vivo. We focus on hemoprotein-dependent reaction pathways that generate and consume NO in the presence of nitrite and consider intermediate nitrogen oxides, including NO2, N2O3, and S-nitrosothiols, that may facilitate nitrite-based signaling in blood vessels and tissues. We also discuss emergent therapeutic strategies that leverage our understanding of these key reaction pathways to target NO signaling and treat a wide range of diseases.
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Affiliation(s)
- Matthew R Dent
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Anthony W DeMartino
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Jesús Tejero
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.,Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States.,Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States
| | - Mark T Gladwin
- Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.,Division of Pulmonary, Allergy and Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.,Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
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19
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Wang Z, Cheng C, Yang X, Zhang C. L-phenylalanine attenuates high salt-induced hypertension in Dahl SS rats through activation of GCH1-BH4. PLoS One 2021; 16:e0250126. [PMID: 33857222 PMCID: PMC8049246 DOI: 10.1371/journal.pone.0250126] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 03/31/2021] [Indexed: 02/07/2023] Open
Abstract
Amino acid metabolism plays an important role in controlling blood pressure by regulating the production of NO and ROS. The present study examined amino acid levels in the serum of Dahl SS rats and SS.13BN rats fed a low or high salt diet. We observed that 8 of 27 amino acids responded to a high salt diet in SS rats. Thus, we hypothesized that a defect in amino acids may contribute to the development of salt-induced hypertension. L-phenylalanine was used to treat SS rats with a low or high salt diet. The results demonstrated that L-phenylalanine supplementation significantly enhanced the serum nitrite levels and attenuated the high salt-induced hypertension in SS rats. Low levels of BH4 and nitrite and the impaired vascular response to acetylcholine were rescued by L-phenylalanine supplementation. Moreover, increased GTP cyclohydrolase (GCH1) mRNA, levels of BH4 and nitrite, and reduced superoxide production were observed in the kidneys of hypertensive SS rats with L-phenylalanine. The antihypertensive effects of L-phenylalanine might be mediated by enhancing BH4 biosynthesis and decreasing superoxide production from NO synthase, thereby protecting vascular and kidney function with reduced ROS and elevated NO levels. The present study demonstrated that L-phenylalanine supplementation restored vascular function, suggesting L-phenylalanine represented a potential target to attenuate high salt-sensitive hypertension through GCH1-BH4.
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Affiliation(s)
- Zhengjun Wang
- School of Psychology, Shaanxi Normal University and Key Laboratory for Behavior and Cognitive Neuroscience of Shaanxi Province, Xi’an, China
- * E-mail: (ZW); (CZ)
| | - Chen Cheng
- School of Psychology, Shaanxi Normal University and Key Laboratory for Behavior and Cognitive Neuroscience of Shaanxi Province, Xi’an, China
| | - Xiaoyu Yang
- School of Life Science, Shaanxi Normal University, Xi’an, China
| | - Chen Zhang
- College of Animal Sciences, Zhejiang University, Hangzhou, China
- School of Life Sciences, Northwestern Polytechnical University, Xi’an, China
- * E-mail: (ZW); (CZ)
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Panday S, Kar S, Kavdia M. How does ascorbate improve endothelial dysfunction? - A computational analysis. Free Radic Biol Med 2021; 165:111-126. [PMID: 33497797 DOI: 10.1016/j.freeradbiomed.2021.01.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 12/23/2020] [Accepted: 01/14/2021] [Indexed: 01/02/2023]
Abstract
Low levels of ascorbate (Asc) are observed in cardiovascular and neurovascular diseases. Asc has therapeutic potential for the treatment of endothelial dysfunction, which is characterized by a reduction in nitric oxide (NO) bioavailability and increased oxidative stress in the vasculature. However, the potential mechanisms remain poorly understood for the Asc mitigation of endothelial dysfunction. In this study, we developed an endothelial cell based computational model integrating endothelial cell nitric oxide synthase (eNOS) biochemical pathway with downstream reactions and interactions of oxidative stress, tetrahydrobiopterin (BH4) synthesis and biopterin ratio ([BH4]/[TBP]), Asc and glutathione (GSH). We quantitatively analyzed three Asc mediated mechanisms that are reported to improve/maintain endothelial cell function. The mechanisms include the reduction of •BH3 to BH4, direct scavenging of superoxide (O2•-) and peroxynitrite (ONOO-) and increasing eNOS activity. The model predicted that Asc at 0.1-100 μM concentrations improved endothelial cell NO production, total biopterin and biopterin ratio in a dose dependent manner and the extent of cellular oxidative stress. Asc increased BH4 availability and restored eNOS coupling under oxidative stress conditions. Asc at concentrations of 1-10 mM reduced O2•- and ONOO- levels and could act as an antioxidant. We predicted that glutathione peroxidase and peroxiredoxin in combination with GSH and Asc can restore eNOS coupling and NO production under oxidative stress conditions. Asc supplementation may be used as an effective therapeutic strategy when BH4 levels are depleted. This study provides detailed understanding of the mechanism responsible and the optimal cellular Asc levels for improvement in endothelial dysfunction.
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Affiliation(s)
- Sheetal Panday
- Department of Biomedical Engineering, Wayne State University, Detroit, 48202, MI, USA
| | - Saptarshi Kar
- College of Engineering and Technology, American University of the Middle East, Kuwait
| | - Mahendra Kavdia
- Department of Biomedical Engineering, Wayne State University, Detroit, 48202, MI, USA.
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21
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Akaihata H, Hata J, Tanji R, Honda-Takinami R, Matsuoka K, Sato Y, Kataoka M, Ogawa S, Kojima Y. Tetrahydrobiopterin prevents chronic ischemia-related lower urinary tract dysfunction through the maintenance of nitric oxide bioavailability. Sci Rep 2020; 10:19844. [PMID: 33199757 PMCID: PMC7670448 DOI: 10.1038/s41598-020-76948-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 11/03/2020] [Indexed: 12/28/2022] Open
Abstract
This study aimed to investigate the influence of chronic ischemia on nitric oxide biosynthesis in the bladder and the effect of administering tetrahydrobiopterin (BH4), a cofactor for endothelial nitric oxide synthase (eNOS), on chronic ischemia-related lower urinary tract dysfunction (LUTD). This study divided male Sprague-Dawley rats into Control, chronic bladder ischemia (CBI) and CBI with oral BH4 supplementation (CBI/BH4) groups. In the CBI group, bladder capacity and bladder muscle strip contractility were significantly lower, and arterial wall was significantly thicker than in Controls. Significant improvements were seen in bladder capacity, muscle strip contractility and arterial wall thickening in the CBI/BH4 group as compared with the CBI group. Western blot analysis of bladder showed expressions of eNOS (p = 0.043), HIF-1α (p < 0.01) and dihydrofolate reductase (DHFR) (p < 0.01), which could regenerate BH4, were significantly higher in the CBI group than in Controls. In the CBI/BH4 group, HIF-1α (p = 0.012) and DHFR expressions (p = 0.018) were significantly decreased compared with the CBI group. Our results suggest that chronic ischemia increases eNOS and DHFR in the bladder to prevent atherosclerosis progression. However, DHFR could not synthesize sufficient BH4 relative to the increased eNOS, resulting in LUTD. BH4 supplementation protects lower urinary tract function by promoting eNOS activity.
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Affiliation(s)
- Hidenori Akaihata
- Department of Urology, Fukushima Medical University of School of Medicine, Fukushima, 960-1295, Japan.
| | - Junya Hata
- Department of Urology, Fukushima Medical University of School of Medicine, Fukushima, 960-1295, Japan
| | - Ryo Tanji
- Department of Urology, Fukushima Medical University of School of Medicine, Fukushima, 960-1295, Japan
| | - Ruriko Honda-Takinami
- Department of Urology, Fukushima Medical University of School of Medicine, Fukushima, 960-1295, Japan
| | - Kanako Matsuoka
- Department of Urology, Fukushima Medical University of School of Medicine, Fukushima, 960-1295, Japan
| | - Yuichi Sato
- Department of Urology, Fukushima Medical University of School of Medicine, Fukushima, 960-1295, Japan
| | - Masao Kataoka
- Department of Urology, Fukushima Medical University of School of Medicine, Fukushima, 960-1295, Japan
| | - Soichiro Ogawa
- Department of Urology, Fukushima Medical University of School of Medicine, Fukushima, 960-1295, Japan
| | - Yoshiyuki Kojima
- Department of Urology, Fukushima Medical University of School of Medicine, Fukushima, 960-1295, Japan
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22
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Fiorello ML, Treweeke AT, Macfarlane DP, Megson IL. The impact of glucose exposure on bioenergetics and function in a cultured endothelial cell model and the implications for cardiovascular health in diabetes. Sci Rep 2020; 10:19547. [PMID: 33177612 PMCID: PMC7659000 DOI: 10.1038/s41598-020-76505-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 10/19/2020] [Indexed: 12/22/2022] Open
Abstract
Cardiovascular disease is the primary driver of morbidity and mortality associated with diabetes. Hyperglycaemia is implicated in driving endothelial dysfunction that might underpin the link between diabetes and cardiovascular disease. This study was designed to determine the impact of chronic preconditioning of cells to hyperglycaemia and transient switching of cultured endothelial cells between hyper- and normo-glycaemic conditions on bioenergetic and functional parameters. Immortalised EA.hy926 endothelial cells were cultured through multiple passages under normoglycaemic (5.5 mM) or hyperglycaemic (25 mM) conditions. Cells were subsequently subjected (48 h) to continued normo- or hyperglycaemic exposure, or were switched to the alternative glycaemic condition, or to an intermediate glucose concentration (12.5 mM) and metabolic activity, together with key markers of function were measured. Cells habituated to hyperglycaemia were energetically quiescent. Functional activity, characterised by the measurement of nitric oxide, endothelin-1, tissue plasminogen activator and plasminogen activator inhibitor-1, was depressed by exposure to high glucose, with the reduction in nitric oxide production being the most notable. Function was more responsive to acute changes in extracellular glucose than were bioenergetic changes. We conclude that glucose is a key determinant of endothelial function. The study highlights the importance of chronic glucose exposure on cell phenotype and emphasises the need to pay close attention to glucose preconditioning in interpreting results under culture conditions.
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Affiliation(s)
- Maria Luisa Fiorello
- Division of Biomedical Sciences, Centre for Health Science, University of the Highlands and Islands, Inverness, IV2 4JH, UK
| | - Andrew T Treweeke
- Division of Biomedical Sciences, Centre for Health Science, University of the Highlands and Islands, Inverness, IV2 4JH, UK
| | | | - Ian L Megson
- Division of Biomedical Sciences, Centre for Health Science, University of the Highlands and Islands, Inverness, IV2 4JH, UK.
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23
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Malekmohammad K, Sewell RD, Rafieian-Kopaei M. Mechanisms of Medicinal Plant Activity on Nitric Oxide (NO) Bioavailability as Prospective Treatments for Atherosclerosis. Curr Pharm Des 2020; 26:2591-2601. [DOI: 10.2174/1381612826666200318152049] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 02/28/2020] [Indexed: 02/07/2023]
Abstract
Background and objective:
Atherosclerosis is one of the leading causes of human morbidity globally
and reduced bioavailability of vascular nitric oxide (NO) has a critical role in the progression and development of
the atherosclerotic disease. Loss of NO bioavailability, for example via a deficiency of the substrate (L-arginine)
or cofactors for endothelial nitric oxide synthase (eNOS), invariably leads to detrimental vascular effects such as
impaired endothelial function and increased smooth muscle cell proliferation, deficiency of the substrate (Larginine)
or cofactors for eNOS. Various medicinal plants and their bioactive compounds or secondary metabolites
with fewer side effects are potentially implicated in preventing cardiovascular disease by increasing NO
bioavailability, thereby ameliorating endothelial dysfunction. In this review, we describe the most notable medicinal
plants and their bioactive compounds that may be appropriate for enhancing NO bioavailability, and
treatment of atherosclerosis.
Methods:
The material in this article was obtained from noteworthy scientific databases, including Web of Science,
PubMed, Science Direct, Scopus and Google Scholar.
Results:
Medicinal plants and their bioactive compounds influence NO production through diverse mechanisms
including the activation of the nuclear factor kappa B (NF-κB) signaling pathway, activating protein kinase C
(PKC)-α, stimulating protein tyrosine kinase (PTK), reducing the conversion of nitrite to NO via nitrate-nitrite
reduction pathways, induction of eNOS, activating the phosphatidylinositol 3-kinase (PI3K)/serine threonine
protein kinase B (AKT) (PI3K/AKT/eNOS/NO) pathway and decreasing oxidative stress.
Conclusion:
Medicinal plants and/or their constituent bioactive compounds may be considered as safe therapeutic
options for enhancing NO bioavailability and prospective preventative therapy for atherosclerosis.
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Affiliation(s)
| | - Robert D.E. Sewell
- Cardiff School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3NB. Wales, United Kingdom
| | - Mahmoud Rafieian-Kopaei
- Medical Plants Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran
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24
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Pérez-Torres I, Manzano-Pech L, Rubio-Ruíz ME, Soto ME, Guarner-Lans V. Nitrosative Stress and Its Association with Cardiometabolic Disorders. Molecules 2020; 25:molecules25112555. [PMID: 32486343 PMCID: PMC7321091 DOI: 10.3390/molecules25112555] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/28/2020] [Accepted: 05/29/2020] [Indexed: 02/07/2023] Open
Abstract
Reactive nitrogen species (RNS) are formed when there is an abnormal increase in the level of nitric oxide (NO) produced by the inducible nitric oxide synthase (iNOS) and/or by the uncoupled endothelial nitric oxide synthase (eNOS). The presence of high concentrations of superoxide anions (O2−) is also necessary for their formation. RNS react three times faster than O2− with other molecules and have a longer mean half life. They cause irreversible damage to cell membranes, proteins, mitochondria, the endoplasmic reticulum, nucleic acids and enzymes, altering their activity and leading to necrosis and to cell death. Although nitrogen species are important in the redox imbalance, this review focuses on the alterations caused by the RNS in the cellular redox system that are associated with cardiometabolic diseases. Currently, nitrosative stress (NSS) is implied in the pathogenesis of many diseases. The mechanisms that produce damage remain poorly understood. In this paper, we summarize the current knowledge on the participation of NSS in the pathology of cardiometabolic diseases and their possible mechanisms of action. This information might be useful for the future proposal of anti-NSS therapies for cardiometabolic diseases.
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Affiliation(s)
- Israel Pérez-Torres
- Vascular Biomedicine Department, Instituto Nacional de Cardiología “Ignacio Chávez”, Juan Badiano 1, Sección XVI, Tlalpan, México City 14080, Mexico;
- Correspondence: (I.P.-T.); (V.G.-L.)
| | - Linaloe Manzano-Pech
- Vascular Biomedicine Department, Instituto Nacional de Cardiología “Ignacio Chávez”, Juan Badiano 1, Sección XVI, Tlalpan, México City 14080, Mexico;
| | - María Esther Rubio-Ruíz
- Physiology Department, Instituto Nacional de Cardiología “Ignacio Chávez”, Juan Badiano 1, Sección XVI, Tlalpan, México City 14080, Mexico;
| | - María Elena Soto
- Immunology Department, Instituto Nacional de Cardiología “Ignacio Chávez”, Juan Badiano 1, Sección XVI, Tlalpan, México City 14080, Mexico;
| | - Verónica Guarner-Lans
- Physiology Department, Instituto Nacional de Cardiología “Ignacio Chávez”, Juan Badiano 1, Sección XVI, Tlalpan, México City 14080, Mexico;
- Correspondence: (I.P.-T.); (V.G.-L.)
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25
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Łuczak A, Madej M, Kasprzyk A, Doroszko A. Role of the eNOS Uncoupling and the Nitric Oxide Metabolic Pathway in the Pathogenesis of Autoimmune Rheumatic Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:1417981. [PMID: 32351667 PMCID: PMC7174952 DOI: 10.1155/2020/1417981] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 03/31/2020] [Indexed: 12/15/2022]
Abstract
Atherosclerosis and its clinical complications constitute the major healthcare problems of the world population. Due to the central role of endothelium throughout the atherosclerotic disease process, endothelial dysfunction is regarded as a common mechanism for various cardiovascular (CV) disorders. It is well established that patients with rheumatic autoimmune diseases are characterized by significantly increased prevalence of cardiovascular morbidity and mortality compared with the general population. The current European guidelines on cardiovascular disease (CVD) prevention in clinical practice recommend to use a 1,5-factor multiplier for CV risk in rheumatoid arthritis as well as in other autoimmune inflammatory diseases. However, mechanisms of accelerated atherosclerosis in these diseases, especially in the absence of traditional risk factors, still remain unclear. Oxidative stress plays the major role in the endothelial dysfunction and recently is strongly attributed to endothelial NO synthase dysfunction (eNOS uncoupling). Converted to a superoxide-producing enzyme, uncoupled eNOS not only leads to reduction of the nitric oxide (NO) generation but also potentiates the preexisting oxidative stress, which contributes significantly to atherogenesis. However, to date, there are no systemic analyses on the role of eNOS uncoupling in the excess CV mortality linked with autoimmune rheumatic diseases. The current review paper addresses this issue.
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Affiliation(s)
- Anna Łuczak
- Department of Rheumatology, Wroclaw Medical University, Poland
| | - Marta Madej
- Department of Rheumatology, Wroclaw Medical University, Poland
| | - Agata Kasprzyk
- Department of Rheumatology, Wroclaw Medical University, Poland
| | - Adrian Doroszko
- Department of Internal Medicine, Hypertension and Clinical Oncology, Wroclaw Medical University, Poland
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26
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Ekeloef S, Oreskov JO, Falkenberg A, Burcharth J, Schou-Pedersen AMV, Lykkesfeldt J, Gögenur I. Endothelial dysfunction and myocardial injury after major emergency abdominal surgery: a prospective cohort study. BMC Anesthesiol 2020; 20:67. [PMID: 32178626 PMCID: PMC7075012 DOI: 10.1186/s12871-020-00977-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 03/02/2020] [Indexed: 01/04/2023] Open
Abstract
Background Preoperative endothelial dysfunction is a predictor of myocardial injury and major adverse cardiac events. Non-cardiac surgery is known to induce acute endothelial changes. The aim of this explorative cohort study was to assess the extent of systemic endothelial dysfunction after major emergency abdominal surgery and the potential association with postoperative myocardial injury. Methods Patients undergoing major emergency abdominal surgery were included in this prospective cohort study. The primary outcome was the change in endothelial function expressed as the reactive hyperemia index from 4-24 h after surgery until postoperative day 3–5. The reactive hyperemia index was assessed by non-invasive digital pulse tonometry. Secondary outcomes included changes in biomarkers of nitric oxide metabolism and bioavailability. All assessments were performed at the two separate time points in the postoperative period. Clinical outcomes included myocardial injury within the third postoperative day and major adverse cardiovascular events within 30 days of surgery. Results Between October 2016 and June 2017, 83 patients were included. The first assessment of the endothelial function, 4–24 h, was performed 15.8 (SD 6.9) hours after surgery and the second assessment, postoperative day 3–5, was performed 83.7 (SD 19.8) hours after surgery. The reactive hyperemia index was suppressed early after surgery and did not increase significantly; 1.64 (95% CI 1.52–177) at 4–24 h after surgery vs. 1.75 (95% CI 1.63–1.89) at postoperative day 3–5, p = 0.34. The L-arginine/ADMA ratio, expressing the nitric oxide production, was reduced in the perioperative period and correlated significantly with the reactive hyperemia index. A total of 16 patients (19.3%) had a major adverse cardiovascular event, of which 11 patients (13.3%) had myocardial injury. The L-arginine/ADMA ratio was significantly decreased at 4–24 h after surgery in patients suffering myocardial injury. Conclusion This explorative pathophysiological study showed that acute systemic endothelial dysfunction was present early after major emergency abdominal surgery and remained unchanged until day 3–5 after the procedure. Early postoperative disturbances in the nitric oxide bioavailability might add to the pathogenesis of myocardial injury. This pathophysiological link should be confirmed in larger studies. Trial registration clinicaltrials.gov no. NCT03010969.
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Affiliation(s)
- Sarah Ekeloef
- Center for Surgical Science, Department of Surgery, Zealand University Hospital, Lykkebækvej 1, 4600, Koege, Denmark.
| | - Jakob Ohm Oreskov
- Center for Surgical Science, Department of Surgery, Zealand University Hospital, Lykkebækvej 1, 4600, Koege, Denmark
| | - Andreas Falkenberg
- Center for Surgical Science, Department of Surgery, Zealand University Hospital, Lykkebækvej 1, 4600, Koege, Denmark
| | - Jakob Burcharth
- Center for Surgical Science, Department of Surgery, Zealand University Hospital, Lykkebækvej 1, 4600, Koege, Denmark
| | | | - Jens Lykkesfeldt
- Faculty of Health & Medical Sciences, University of Copenhagen, 1870, Frederiksberg, Denmark
| | - Ismail Gögenur
- Center for Surgical Science, Department of Surgery, Zealand University Hospital, Lykkebækvej 1, 4600, Koege, Denmark
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27
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Evers RAF, van Vliet D, van Spronsen FJ. Tetrahydrobiopterin treatment in phenylketonuria: A repurposing approach. J Inherit Metab Dis 2020; 43:189-199. [PMID: 31373030 DOI: 10.1002/jimd.12151] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 07/01/2019] [Accepted: 07/04/2019] [Indexed: 12/24/2022]
Abstract
In phenylketonuria (PKU) patients, early diagnosis by neonatal screening and immediate institution of a phenylalanine-restricted diet can prevent severe intellectual impairment. Nevertheless, outcome remains suboptimal in some patients asking for additional treatment strategies. Tetrahydrobiopterin (BH4 ) could be one of those treatment options, as it may not only increase residual phenylalanine hydroxylase activity in BH4 -responsive PKU patients, but possibly also directly improves neurocognitive functioning in both BH4 -responsive and BH4 -unresponsive PKU patients. In the present review, we aim to further define the theoretical working mechanisms by which BH4 might directly influence neurocognitive functioning in PKU having passed the blood-brain barrier. Further research should investigate which of these mechanisms are actually involved, and should contribute to the development of an optimal BH4 treatment regimen to directly improve neurocognitive functioning in PKU. Such possible repurposing approach of BH4 treatment in PKU may improve neuropsychological outcome and mental health in both BH4 -responsive and BH4 -unresponsive PKU patients.
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Affiliation(s)
- Roeland A F Evers
- Division of Metabolic Diseases, University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Groningen, The Netherlands
| | - Danique van Vliet
- Division of Metabolic Diseases, University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Groningen, The Netherlands
| | - Francjan J van Spronsen
- Division of Metabolic Diseases, University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Groningen, The Netherlands
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28
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Gheibi S, Samsonov AP, Gheibi S, Vazquez AB, Kashfi K. Regulation of carbohydrate metabolism by nitric oxide and hydrogen sulfide: Implications in diabetes. Biochem Pharmacol 2020; 176:113819. [PMID: 31972170 DOI: 10.1016/j.bcp.2020.113819] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 01/15/2020] [Indexed: 12/19/2022]
Abstract
Nitric oxide (NO) and hydrogen sulfide (H2S) are two gasotransmitters that are produced in the human body and have a key role in many of the physiological activities of the various organ systems. Decreased NO bioavailability and deficiency of H2S are involved in the pathophysiology of type 2 diabetes and its complications. Restoration of NO levels have favorable metabolic effects in diabetes. The role of H2S in pathophysiology of diabetes is however controversial; H2S production is decreased during development of obesity, diabetes, and its complications, suggesting the potential therapeutic effects of H2S. On the other hand, increased H2S levels disturb the pancreatic β-cell function and decrease insulin secretion. In addition, there appear to be important interactions between NO and H2S at the levels of both biosynthesis and signaling pathways, yet clear an insight into this relationship is lacking. H2S potentiates the effects of NO in the cardiovascular system as well as NO release from its storage pools. Likewise, NO increases the activity and the expression of H2S-generating enzymes. Inhibition of NO production leads to elimination/attenuation of the cardioprotective effects of H2S. Regarding the increasing interest in the therapeutic applications of NO or H2S-releasing molecules in a variety of diseases, particularly in the cardiovascular disorders, much is to be learned about their function in glucose/insulin metabolism, especially in diabetes. The aim of this review is to provide a better understanding of the individual and the interactive roles of NO and H2S in carbohydrate metabolism.
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Affiliation(s)
- Sevda Gheibi
- Department of Clinical Sciences in Malmö, Unit of Molecular Metabolism, Lund University Diabetes Centre, Clinical Research Center, Malmö University Hospital, Lund University, Malmö, Sweden.
| | - Alan P Samsonov
- Department of Molecular, Cellular and Biomedical Sciences, Sophie Davis School of Biomedical Education, City University of New York School of Medicine, New York, NY, USA
| | - Shahsanam Gheibi
- Maternal and Childhood Obesity Research Center, Urmia University of Medical Sciences, Urmia, Iran
| | - Alexandra B Vazquez
- Department of Molecular, Cellular and Biomedical Sciences, Sophie Davis School of Biomedical Education, City University of New York School of Medicine, New York, NY, USA
| | - Khosrow Kashfi
- Department of Molecular, Cellular and Biomedical Sciences, Sophie Davis School of Biomedical Education, City University of New York School of Medicine, New York, NY, USA; Graduate Program in Biology, City University of New York Graduate Center, New York, NY, USA.
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29
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Mannino GC, Pezzilli S, Averta C, Fuoco A, Spiga R, Mancuso E, Di Fatta C, Perticone F, Prudente S, Trischitta V, Andreozzi F, Sesti G. A functional variant of the dimethylarginine dimethylaminohydrolase-2 gene is associated with myocardial infarction in type 2 diabetic patients. Cardiovasc Diabetol 2019; 18:102. [PMID: 31409409 PMCID: PMC6693196 DOI: 10.1186/s12933-019-0906-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 08/05/2019] [Indexed: 02/06/2023] Open
Abstract
Background Myocardial infarction is the main mortality cause in patients with type 2 diabetes (T2DM). Endothelial dysfunction due to reduced bioavailability of nitric oxide (NO) is an early step of atherogenesis. Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NO synthesis, and it is metabolized by the enzymes dimethylarginine dimethylaminohydrolase (DDAH) 1 and 2. The functional variant rs9267551 C, in the promoter region of DDAH2, has been linked to increased DDAH2 expression, and lower ADMA plasma levels, and was associated with lower risk of coronary artery disease in large-scale genome-wide association studies (GWAS) performed in the general population. However, it is unknown whether this association holds true in T2DM patients. To address this issue, we investigated whether rs9267551 is associated with risk of myocardial infarction in two cohorts of T2DM patients. Methods SNP rs9267551 was genotyped in 1839 White T2DM patients from the Catanzaro Study (CZ, n = 1060) and the Gargano Heart Study-cross sectional design (GHS, n = 779). Cases were patients with a previous myocardial infarction, controls were asymptomatic patients with neither previous myocardial ischemia nor signs of it at resting and during a maximal symptom limited stress electrocardiogram. Results Carriers of allele rs9267551 C showed a dose dependent reduction in the risk of myocardial infarction [(CZ = OR 0.380, 95% CI 0.175–0.823, p = 0.014), (GHS = 0.497, 0.267–0.923, p = 0.027), (Pooled = 0.458, 0.283–0.739, p = 0.001)] which remained significant after adjusting for sex, age, BMI, smoking, HbA1c, total cholesterol HDL, and triglyceride levels [(CZ = 0.307, 0.106–0.885, p = 0.029), (GHS = 0.512, 0.270–0.970, p = 0.040), (Pooled = 0.458, 0.266–0.787, p = 0.005)]. Conclusions We found that rs9267551 polymorphism is significantly associated with myocardial infarction in T2DM patients of European ancestry from two independent cohorts. It is possible that in subjects carrying the protective C allele less ADMA accumulates in endothelial cells causing vascular protection as a consequence of higher nitric oxide availability.
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Affiliation(s)
- Gaia Chiara Mannino
- Department of Medical and Surgical Sciences, University "Magna Graecia" of Catanzaro, Viale Europa, 88100, Catanzaro, Italy
| | - Serena Pezzilli
- Research Unit of Metabolic and Cardiovascular Diseases, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy.,Medical Genetics, University Chieti-Pescara, Pescara, Chieti Scalo, Italy
| | - Carolina Averta
- Department of Medical and Surgical Sciences, University "Magna Graecia" of Catanzaro, Viale Europa, 88100, Catanzaro, Italy
| | - Anastasia Fuoco
- Department of Medical and Surgical Sciences, University "Magna Graecia" of Catanzaro, Viale Europa, 88100, Catanzaro, Italy
| | - Rosangela Spiga
- Department of Medical and Surgical Sciences, University "Magna Graecia" of Catanzaro, Viale Europa, 88100, Catanzaro, Italy
| | - Elettra Mancuso
- Department of Medical and Surgical Sciences, University "Magna Graecia" of Catanzaro, Viale Europa, 88100, Catanzaro, Italy
| | - Concetta Di Fatta
- Department of Medical and Surgical Sciences, University "Magna Graecia" of Catanzaro, Viale Europa, 88100, Catanzaro, Italy
| | - Francesco Perticone
- Department of Medical and Surgical Sciences, University "Magna Graecia" of Catanzaro, Viale Europa, 88100, Catanzaro, Italy
| | - Sabrina Prudente
- Research Unit of Metabolic and Cardiovascular Diseases, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Vincenzo Trischitta
- Research Unit of Metabolic and Cardiovascular Diseases, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy.,Department of Experimental Medicine, Sapienza University, Rome, Italy
| | - Francesco Andreozzi
- Department of Medical and Surgical Sciences, University "Magna Graecia" of Catanzaro, Viale Europa, 88100, Catanzaro, Italy.
| | - Giorgio Sesti
- Department of Medical and Surgical Sciences, University "Magna Graecia" of Catanzaro, Viale Europa, 88100, Catanzaro, Italy
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30
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Pharmacological inhibition of guanosine triphosphate cyclohydrolase1 elevates tyrosine phosphorylation of caveolin1 and cellular senescence. Eur J Pharmacol 2019; 848:1-10. [PMID: 30690003 DOI: 10.1016/j.ejphar.2019.01.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 01/15/2019] [Accepted: 01/18/2019] [Indexed: 01/02/2023]
Abstract
The role of 2,4-diamino-6-hydroxypyrimidine (DAHP), on cellular-senescence remains unclear as differential effects of DAHP have been reported in cardiovascular and cerebrovascular systems. We investigated the effect of pharmacologically-induced guanosine-triphosphate-cyclohydrolase1 (GTPCH1)-inhibition, through DAHP, on cellular-senescence in experimentally-induced diabetic and non-diabetic Wistar rats. Cellular-senescence was evaluated through senescence-associated events, namely, cell-cycle-arrest of peripheral blood mononuclear cells (PBMNCs); myocardial DNA fragmentation, total antioxidant capacity (TAC), telomerase-activity, nicotinamide adenine dinucleotide (NAD+)-content and tyrosine14-phosphorylation of caveolin1 (pY14) in similarly-aged, pubertal Wistar rats with streptozotocin (STZ) and/or DAHP. Oxidative stress (OS) indices such as myocardial biopterin concentrations (tetrahydrobiopterin-BH4 and dihydrobiopterin-BH2) and plasma total nitrite and nitrate (NOx) were determined. DAHP, per se, exhibited distinct senescence; in addition, in STZ+DAHP (the cardiomyopathy model), there was a marked accumulation of cells in G0G1 phase, as evidenced through flow-cytometry analysis, as-well-as fragmented DNA, than the respective controls suggesting the DAHP-mediated onset of senescence in circulating cells and the myocardium, with or without STZ. Concentrations of BH4 and BH2, and NOx were impaired in STZ and/or DAHP, indicating elevated OS in the treatment groups. In the independent treatment groups or the combination treatment, typical senescence indicators including myocardial telomerase-activity, NAD+-content and TAC were significantly reduced, while there was a marked elevation in the concentrations of pY14 as compared to the respective controls, reinforcing the occurrence of senescence in PBMNCs and the myocardium. We postulate that DAHP promotes early onset of cellular-senescence, potentially through OS-mediated cellular events in diabetic or non-diabetic models.
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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: 277] [Impact Index Per Article: 55.4] [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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Peri-operative endothelial dysfunction in patients undergoing minor abdominal surgery. Eur J Anaesthesiol 2019; 36:130-134. [DOI: 10.1097/eja.0000000000000935] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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McDonald JD, Mah E, Chitchumroonchokchai C, Dey P, Labyk AN, Villamena FA, Volek JS, Bruno RS. Dairy milk proteins attenuate hyperglycemia-induced impairments in vascular endothelial function in adults with prediabetes by limiting increases in glycemia and oxidative stress that reduce nitric oxide bioavailability. J Nutr Biochem 2019; 63:165-176. [DOI: 10.1016/j.jnutbio.2018.09.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 09/12/2018] [Accepted: 09/17/2018] [Indexed: 12/11/2022]
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Natarajan M, Habib SL, Reddick RL, Delma CR, Manickam K, Prihoda TJ, Werner SL, Mohan S. Endothelial cell-specific overexpression of endothelial nitric oxide synthase in Ins2Akita mice exacerbates diabetic nephropathy. J Diabetes Complications 2019; 33:23-32. [PMID: 30424931 PMCID: PMC6344355 DOI: 10.1016/j.jdiacomp.2018.10.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 08/13/2018] [Accepted: 10/07/2018] [Indexed: 10/28/2022]
Abstract
Previous studies demonstrated that global deficiency of eNOS in diabetic mice exacerbated renal lesions and that overexpression of eNOS may protect against tissue injury. Our study revealed for the first time overexpression of eNOS leads to disease progression rather than protection. Transgenic mice selectively expressing eNOS in endothelial cells (eNOSTg) were cross bred with Ins2Akita type-1 (AK) diabetic mice to generate eNOS overexpressing eNOSTg/AK mice. Wild type, eNOSTg, AK and eNOSTg/AK mice were assessed for kidney function and blood glucose levels. Remarkably, overexpressing eNOSTg mice showed evidence of unpredicted glomerular injury with segmental mesangiolysis and occasional microaneurysms. Notably, in eNOSTg/AK mice overexpression of eNOS led to increased glomerular/endothelial injury that was associated with increased superoxide levels and renal dysfunction. Results indicate for the first time that overexpressing eNOS in endothelial cells cannot ameliorate diabetic lesions, but paradoxically leads to progression of nephropathy likely due to eNOS uncoupling and superoxide upsurge. This novel finding has a significant impact on current therapeutic strategies to improve endothelial function and prevent progression of diabetic renal disease. Further, the eNOSTg/AK model developed in this study has significant translational potentials for elucidating the underlying mechanism implicated in the deflected function of eNOS in diabetic nephropathy.
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Affiliation(s)
- Mohan Natarajan
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Samy L Habib
- Geriatric Research Education and Clinical Center, South Texas Veterans Healthcare System and Cell Systems & Anatomy, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Robert L Reddick
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Caroline R Delma
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Krishnan Manickam
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Thomas J Prihoda
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Sherry L Werner
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Sumathy Mohan
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
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McDonald JD, Mah E, Dey P, Olmstead BD, Sasaki GY, Villamena FA, Bruno RS. Dairy milk, regardless of fat content, protects against postprandial hyperglycemia-mediated impairments in vascular endothelial function in adults with prediabetes by limiting oxidative stress responses that reduce nitric oxide bioavailability. J Nutr Biochem 2018; 63:129-139. [PMID: 30359862 DOI: 10.1016/j.jnutbio.2018.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 08/30/2018] [Accepted: 10/03/2018] [Indexed: 12/28/2022]
Abstract
Postprandial hyperglycemia (PPH) transiently impairs vascular endothelial function (VEF) in an oxidative-stress-dependent manner by decreasing nitric oxide (NO•) bioavailability. Dairy milk, regardless of fat content, attenuates PPH, but whether this improves VEF by limiting oxidative stress responses that otherwise decrease NO• bioavailability is not known. We hypothesized that nonfat and full-fat dairy milk would similarly improve VEF by attenuating PPH-induced oxidative stress that otherwise decreases NO• biosynthesis and bioavailability. A randomized, crossover trial was conducted in adults with prediabetes (n=22) who ingested glucose (75 g) dissolved in 473 ml of water (GLU), or glucose with an equal volume of nonfat dairy milk (NFM) or full-fat dairy milk (FFM). Prior to and at 30-min intervals for 180 min postprandially, we assessed brachial artery flow-mediated dilation (FMD) and measured circulating biomarkers of glycemic control, oxidative stress and NO• homeostasis. AUC0-180 min for FMD and NO• metabolites was lowest in GLU but relatively greater in NFM and FFM. Compared with GLU, AUCs for glucose, malondialdehyde, F2-isoprostanes and endothelin-1 were similarly lower in dairy trials. Milk-mediated vasoprotection was accompanied by greater levels of plasma arginine and lower levels of asymmetric dimethylarginine and symmetric dimethylarginine. Postprandial insulin, lipids and tetrahydrobiopterin redox status did not differ among trials. Thus, dairy milk, regardless of its fat content, attenuates PPH-mediated impairments in VEF by limiting oxidative stress. This improves NO• bioavailability to the vascular endothelium by increasing arginine availability and limiting competitive inhibition on NO• biosynthesis by asymmetric dimethylarginine.
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Affiliation(s)
- Joshua D McDonald
- Human Nutrition Program, Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Eunice Mah
- Human Nutrition Program, Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA; Biofortis, Merieux NutriSciences, Addison, IL 60101, USA
| | - Priyankar Dey
- Human Nutrition Program, Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Bryan D Olmstead
- Human Nutrition Program, Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Geoffrey Y Sasaki
- Human Nutrition Program, Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Frederick A Villamena
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210, USA
| | - Richard S Bruno
- Human Nutrition Program, Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA.
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Zhang X, Sun D, Song JW, Zullo J, Lipphardt M, Coneh-Gould L, Goligorsky MS. Endothelial cell dysfunction and glycocalyx – A vicious circle. Matrix Biol 2018; 71-72:421-431. [DOI: 10.1016/j.matbio.2018.01.026] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 01/29/2018] [Accepted: 01/30/2018] [Indexed: 12/16/2022]
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Bailey J, Davis S, Shaw A, Diotallevi M, Fischer R, Benson MA, Zhu H, Brown J, Bhattacharya S, Kessler BM, Channon KM, Crabtree MJ. Tetrahydrobiopterin modulates ubiquitin conjugation to UBC13/UBE2N and proteasome activity by S-nitrosation. Sci Rep 2018; 8:14310. [PMID: 30254268 PMCID: PMC6156325 DOI: 10.1038/s41598-018-32481-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 09/06/2018] [Indexed: 12/16/2022] Open
Abstract
Nitric Oxide (NO) is an intracellular signalling mediator, which affects many biological processes via the posttranslational modification of proteins through S-nitrosation. The availability of NO and NOS-derived reactive oxygen species (ROS) from enzymatic uncoupling are determined by the NO synthase cofactor Tetrahydrobiopterin (BH4). Here, using a global proteomics "biotin-switch" approach, we identified components of the ubiquitin-proteasome system to be altered via BH4-dependent NO signalling by protein S-nitrosation. We show S-nitrosation of ubiquitin conjugating E2 enzymes, in particular the catalytic residue C87 of UBC13/UBE2N, leading to impaired polyubiquitylation by interfering with the formation of UBC13~Ub thioester intermediates. In addition, proteasome cleavage activity in cells also seems to be altered by S-nitrosation, correlating with the modification of cysteine residues within the 19S regulatory particle and catalytic subunits of the 20S complex. Our results highlight the widespread impact of BH4 on downstream cellular signalling as evidenced by the effect of a perturbed BH4-dependent NO-Redox balance on critical processes within the ubiquitin-proteasome system (UPS). These studies thereby uncover a novel aspect of NO associated modulation of cellular homeostasis.
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Affiliation(s)
- Jade Bailey
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK
| | - Simon Davis
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7FZ, UK
| | - Andrew Shaw
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK
| | - Marina Diotallevi
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK
| | - Roman Fischer
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7FZ, UK
| | - Matthew A Benson
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK
| | - Hanneng Zhu
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK
| | - James Brown
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK
| | - Shoumo Bhattacharya
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK
| | - Benedikt M Kessler
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7FZ, UK
| | - Keith M Channon
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK
| | - Mark J Crabtree
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford, OX3 9DU, UK.
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Co-ingestion of whole eggs or egg whites with glucose protects against postprandial hyperglycaemia-induced oxidative stress and dysregulated arginine metabolism in association with improved vascular endothelial function in prediabetic men. Br J Nutr 2018; 120:901-913. [PMID: 30160222 DOI: 10.1017/s0007114518002192] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Replacing a portion of a glucose challenge with whole eggs (EGG) or egg whites (WHITE) was shown to protect against glucose-induced impairments in vascular function. We hypothesised in the present study that previously observed vasoprotection following co-ingestion of EGG or WHITE with glucose was attributed to limiting postprandial hyperglycaemia-induced oxidative stress that improves NO∙ bioavailability. Prediabetic men completed a randomised, cross-over study in which they ingested isoenergetic meals containing 100 g glucose (GLU), or 75 g glucose with 1·5 EGG, seven WHITE or two egg yolks (YOLK). At 30 min intervals for 3 h, we assessed plasma NO∙ metabolites, the lipid peroxidation biomarker malondialdehyde, antioxidants, arginine and its methylated metabolites (asymmetric dimethylarginine and symmetric dimethylarginine), tetrahydrobiopterin redox status, vasoconstrictors and inflammatory markers. Compared with GLU, malondialdehyde was lower and NO∙ metabolites were greater in EGG and WHITE, but YOLK was not different from GLU. Malondialdehyde was inversely correlated with NO∙ metabolites and vascular function, whereas NO∙ metabolites were positively correlated with vascular function. Compared with GLU, arginine was greater, but asymmetric and symmetric dimethylarginine and angiotensin-II were lower in all egg-based meals. Antioxidants, tetrahydrobiopterin redox status and inflammatory markers did not differ among treatments. Thus, while each egg-based meal improved arginine metabolism, only EGG and WHITE limited lipid peroxidation. This suggests that vasoprotection mediated by EGG and WHITE likely occurs in an NO∙-dependent manner by improving arginine metabolism and attenuating oxidative stress that otherwise limit NO∙ biosynthesis and bioavailability to the vascular endothelium.
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Oxidative stress induces BH 4 deficiency in male, but not female, SHR. Biosci Rep 2018; 38:BSR20180111. [PMID: 29899168 PMCID: PMC6028750 DOI: 10.1042/bsr20180111] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 06/08/2018] [Accepted: 06/13/2018] [Indexed: 02/07/2023] Open
Abstract
We previously published that female spontaneously hypertensive rats (SHR) have significantly greater nitric oxide (NO) bioavailability and NO synthase (NOS) enzymatic activity in the renal inner medulla (IM) compared with age-matched males, although the mechanism responsible remains unknown. Tetrahydrobiopterin (BH4) is a critical cofactor required for NO generation, and decreases in BH4 as a result of increases in oxidative stress have been implicated in the pathogenesis of hypertension. As male SHR are known to have higher levels of oxidative stress compared with female SHR, we hypothesized that relative BH4 deficiency induced by oxidative stress in male SHR results in lower levels of NOS activity in renal IM compared with females. Twelve-week-old male and female SHR were randomized to receive tempol (30 mg/kg/day via drinking water) or vehicle for 2 weeks. Tempol treatment did not affect blood pressure (BP) in either sex, but reduced peroxynitrite levels only in males. Females had more total biopterin, dihydrobiopterin (BH2), and BH4 levels in renal IMs than males, and tempol treatment eliminated these sex differences. Females had greater total NOS activity in the renal IM than males, and adding exogenous BH4 to the assay increased NOS activity in both sexes. This sex difference in total NOS and the effect of exogenous BH4 were abolished with tempol treatment. We conclude that higher oxidative stress in male SHR results in a relative deficiency of BH4 compared with females, resulting in diminished renal NOS activity in the male.
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LaCorte S. How chronic administration of benzodiazepines leads to unexplained chronic illnesses: A hypothesis. Med Hypotheses 2018; 118:59-67. [PMID: 30037616 DOI: 10.1016/j.mehy.2018.06.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 05/28/2018] [Accepted: 06/19/2018] [Indexed: 11/15/2022]
Abstract
It is thought that an ill defined biochemical cascade may lead to protracted withdrawal symptoms subsequent to discontinuance of routine use of benzodiazepine class drugs and establish chronic illness in some patients. In this review, published findings are presented that support the novel concept that withdrawal from benzodiazepine class drugs can trigger elevated and sustained levels of a potent oxidant called peroxynitrite via potentiation of the L-type voltage-gated calcium channels, and in the later stages of withdrawal, via excessive N-methyl-D-aspartate receptor activity, as well. Potentiation of L-type voltage-gated calcium channels and excessive N-methyl-D-aspartate receptor activity both result in calcium influx into the cell that triggers nitric oxide synthesis. In pathophysiological conditions, such increased nitric oxide synthesis leads to peroxynitrite formation. The downstream effects of peroxynitrite formation that may occur during withdrawal ultimately lead to further peroxynitrite production in a system of overlapping vicious cycles collectively referred to as the NO/ONOO(-) cycle. Once triggered, the elements of the NO/ONOO(-) cycle perpetuate pathophysiology, perhaps including reduced GABAA receptor functioning, that may explain protracted withdrawal associated symptoms while the vicious cycle nature of the NO/ONOO(-) cycle may explain how withdrawal becomes a chronic state. Suboptimal levels of tetrahydrobiopterin may be one risk factor for the development of the protracted withdrawal syndrome as this will lead to partial nitric oxide uncoupling and resultant peroxynitrite formation. Nitric oxide uncoupling results in superoxide production as calcium-dependent nitric oxide synthases attempt to produce nitric oxide in response to L-type voltage-gated calcium channel-mediated calcium influx that is known to occur during withdrawal. The combination of nitric oxide and superoxide produced, as when partial uncoupling occurs, react together in a very rapid, diffusion limited reaction to form peroxynitrite and thereby trigger the NO/ONOO(-) cycle. The NO/ONOO(-) cycle may explain the nature of the protracted withdrawal syndrome and the related constellation of symptoms that are also common in other illnesses characterized as NO/ONOO(-) disorders such as myalgic encephalomyelitis/chronic fatigue syndrome and fibromyalgia.
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Affiliation(s)
- S LaCorte
- Benzodiazepine Information Coalition, 1042 Fort Union Blvd. Suite 1030, Midvale, UT 84047, United States.
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Rabender CS, Bruno N, Alam A, Sundaresan G, Zweit J, Mikkelsen RB. Sepiapterin Enhances Tumor Radio- and Chemosensitivities by Promoting Vascular Normalization. J Pharmacol Exp Ther 2018; 365:536-543. [PMID: 29581154 PMCID: PMC11046730 DOI: 10.1124/jpet.117.245258] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 02/26/2018] [Indexed: 12/22/2022] Open
Abstract
Previously, we demonstrated that nitric oxide (NO) synthase (NOS) is uncoupled in a wide range of solid tumors and that restoring NOS coupling with the tetrahydrobiopterin precursor sepiapterin (SP) inhibits tumor progression. Endothelial dysfunction characterizes the poorly functional vasculature of solid tumors, and since NO is critical for regulation of endothelial function we asked whether SP, by recoupling NOS, improves tumor vasculature structure and function-enhancing chemotherapeutic delivery and response to radiotherapy. MMTV-neu mice with spontaneous breast tumors were treated with SP by oral gavage and evaluated by multispectral optoacoustic tomographic analysis of tumor HbO2 and by tissue staining for markers of hypoxia, blood perfusion, and markers of endothelial and smooth muscle proteins. Recoupling tumor NOS activity results in vascular normalization observed as reduced tumor hypoxia, improved tumor percentage of HbO2 and perfusion, as well as increased pericyte coverage of tumor blood vessels. The normalized vasculature and improved tumor oxygenation led to a greater than 2-fold increase in radiation-induced apoptosis compared with radiation or SP alone. High-performance liquid chromatography analysis of tumor doxorubicin levels showed a greater than 50% increase in doxorubicin uptake and a synergistic effect on tumor cell apoptosis. This study highlights for the first time the importance of NOS uncoupling and endothelial dysfunction in the development of tumor vasculature and presents a new approach for improving the tumoricidal efficacies of chemotherapy and radiotherapy.
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Affiliation(s)
- Christopher S Rabender
- Department of Radiation Oncology (C.S.R., N.B., A.A., R.B.M.) and Center for Molecular Imaging (G.S., J.Z.), Virginia Commonwealth University, Richmond, Virginia
| | - Ninu Bruno
- Department of Radiation Oncology (C.S.R., N.B., A.A., R.B.M.) and Center for Molecular Imaging (G.S., J.Z.), Virginia Commonwealth University, Richmond, Virginia
| | - Asim Alam
- Department of Radiation Oncology (C.S.R., N.B., A.A., R.B.M.) and Center for Molecular Imaging (G.S., J.Z.), Virginia Commonwealth University, Richmond, Virginia
| | - Gobalakrishnan Sundaresan
- Department of Radiation Oncology (C.S.R., N.B., A.A., R.B.M.) and Center for Molecular Imaging (G.S., J.Z.), Virginia Commonwealth University, Richmond, Virginia
| | - Jamal Zweit
- Department of Radiation Oncology (C.S.R., N.B., A.A., R.B.M.) and Center for Molecular Imaging (G.S., J.Z.), Virginia Commonwealth University, Richmond, Virginia
| | - Ross B Mikkelsen
- Department of Radiation Oncology (C.S.R., N.B., A.A., R.B.M.) and Center for Molecular Imaging (G.S., J.Z.), Virginia Commonwealth University, Richmond, Virginia
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Eichinger A, Danecka MK, Möglich T, Borsch J, Woidy M, Büttner L, Muntau AC, Gersting SW. Secondary BH4 deficiency links protein homeostasis to regulation of phenylalanine metabolism. Hum Mol Genet 2018; 27:1732-1742. [PMID: 29514280 DOI: 10.1093/hmg/ddy079] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 02/28/2018] [Indexed: 01/01/2023] Open
Abstract
Metabolic control of phenylalanine concentrations in body fluids is essential for cognitive development and executive function. The hepatic phenylalanine hydroxylating system is regulated by the ratio of l-phenylalanine, which is substrate of phenylalanine hydroxylase (PAH), to the PAH cofactor tetrahydrobiopterin (BH4). Physiologically, phenylalanine availability is governed by nutrient intake, whereas liver BH4 is kept at constant level. In phenylketonuria, PAH deficiency leads to elevated blood phenylalanine and is often caused by PAH protein misfolding with loss of function. Here, we report secondary hepatic BH4 deficiency in Pah-deficient mice. Alterations in de novo synthesis and turnover of BH4 were ruled out as molecular causes. We demonstrate that kinetically instable and aggregation-prone variant Pah proteins trap BH4, shifting the pool of free BH4 towards bound BH4. Interference of PAH protein misfolding with metabolite-based control of l-phenylalanine turnover suggests a mechanistic link between perturbation of protein homeostasis and disturbed regulation of metabolic pathways.
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Affiliation(s)
- Anna Eichinger
- Molecular Pediatrics, Dr von Hauner Children's Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | | | - Tamara Möglich
- Molecular Pediatrics, Dr von Hauner Children's Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - Julia Borsch
- Molecular Pediatrics, Dr von Hauner Children's Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - Mathias Woidy
- University Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Lars Büttner
- Molecular Pediatrics, Dr von Hauner Children's Hospital, Ludwig-Maximilians-Universität, Munich, Germany
| | - Ania C Muntau
- University Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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Ye S, Shan XF, Han WQ, Zhang QR, Gao J, Jin AP, Wang Y, Sun CF, Zhang SL. Microparticles from Patients Undergoing Percutaneous Coronary Intervention Impair Vasodilatation by Uncoupling Endothelial Nitric Oxide Synthase. Shock 2018; 48:201-208. [PMID: 28002238 DOI: 10.1097/shk.0000000000000823] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
OBJECTIVES Percutaneous coronary interventions (PCIs) save countless acute myocardial infarction (AMI) patients. However, endothelial injury is still an inevitable complication. Circulating microparticles (MPs) play important roles in vascular dysfunction. Whether PCI affects function of MPs remains unclear. METHODS MPs were obtained from AMI patients (n = 38) both preoperatively and 24 h after PCI, and healthy subjects (n = 20). MPs origins were tested by flow cytometry. Rat thoracic aortas were incubated with MPs to determine the effects of MPs on phosphorylation of endothelial nitric oxide synthase (eNOS), caveolin-1 expression, eNOS association with heat shock protein 90 (Hsp90), generation of nitric oxide (NO) and superoxide anion (O2), and endothelial-dependent vasodilatation. RESULTS Compared with healthy subjects, MP concentrations increased in AMI patients. Undergoing PCI had no further effect on MPs concentration, but it results in increased endothelial-derived MPs proportion and decreased platelet-derived MP ratio. MPs from AMI patients decreased eNOS phosphorylation at Ser1177, increased eNOS phosphorylation at T495 and caveolin-1 expression, decreased eNOS association with Hsp90, decreased NO production but increased (O2) generation, damaged endothelial-dependent vasodilatation. All of these effects of MPs were strengthened by PCI. CONCLUSIONS PCI further enhances the vascular injury effect of MPs. Circulating MPs may be a potential therapeutic target for patients undergoing PCI.
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Affiliation(s)
- Sha Ye
- *Geriatric Vasculocardiology Department, The Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China †Department of Children's Cardiac Surgery, The First Affiliated Hospital of Xinjiang Medical University, Urumuqi, Xinjiang, China ‡Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi, China §Department of Cardiovascular Medicine, MOE, Ion Channel Disease Laboratory, MOE Key Laboratory of Environment and Genes Related to Diseases, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, China
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Ohashi A, Mamada K, Harada T, Naito M, Takahashi T, Aizawa S, Hasegawa H. Organic anion transporters, OAT1 and OAT3, are crucial biopterin transporters involved in bodily distribution of tetrahydrobiopterin and exclusion of its excess. Mol Cell Biochem 2017; 435:97-108. [PMID: 28534121 PMCID: PMC5632347 DOI: 10.1007/s11010-017-3060-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2016] [Accepted: 05/04/2017] [Indexed: 01/05/2023]
Abstract
Tetrahydrobiopterin (BH4) is a common coenzyme of phenylalanine-, tyrosine-, and tryptophan hydroxylases, alkylglycerol monooxygenase, and NO synthases (NOS). Synthetic BH4 is used medicinally for BH4-responsive phenylketonuria and inherited BH4 deficiency. BH4 supplementation has also drawn attention as a therapy for various NOS-related cardio-vascular diseases, but its use has met with limited success in decreasing BH2, the oxidized form of BH4. An increase in the BH2/BH4 ratio leads to NOS dysfunction. Previous studies revealed that BH4 supplementation caused a rapid urinary loss of BH4 accompanied by an increase in the blood BH2/BH4 ratio and an involvement of probenecid-sensitive but unknown transporters was strongly suggested in these processes. Here we show that OAT1 and OAT3 enabled cells to take up BP (BH4 and/or BH2) in a probenecid-sensitive manner using rat kidney slices and transporter-expressing cell systems, LLC-PK1 cells and Xenopus oocytes. Both OAT1 and OAT3 preferred BH2 and sepiapterin as their substrate roughly 5- to 10-fold more than BH4. Administration of probenecid acutely reduced the urinary exclusion of endogenous BP accompanied by a rise in blood BP in vivo. These results indicated that OAT1 and OAT3 played crucial roles: (1) in determining baseline levels of blood BP by excluding endogenous BP through the urine, (2) in the rapid distribution to organs of exogenous BH4 and the exclusion to urine of a BH4 excess, particularly when BH4 was administered, and (3) in scavenging blood BH2 by cellular uptake as the gateway to the salvage pathway of BH4, which reduces BH2 back to BH4.
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Affiliation(s)
- Akiko Ohashi
- Department of Anatomy, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda, Tokyo, 101-8310, Japan.
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Chiyoda, Tokyo, 101-8310, Japan.
| | - Kaori Mamada
- Department of Biosciences, Teikyo University of Science and Technology, Uenohara, Yamanashi, 401-0193, Japan
| | - Tomonori Harada
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, Itabashi, Tokyo, 173-8610, Japan
| | - Masako Naito
- Department of Anatomy, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda, Tokyo, 101-8310, Japan
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Chiyoda, Tokyo, 101-8310, Japan
| | - Tomihisa Takahashi
- Department of Anatomy, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda, Tokyo, 101-8310, Japan
- Division of Functional Morphology, Dental Research Center, Nihon University School of Dentistry, Chiyoda, Tokyo, 101-8310, Japan
| | - Shin Aizawa
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, Itabashi, Tokyo, 173-8610, Japan
| | - Hiroyuki Hasegawa
- Department of Anatomy, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda, Tokyo, 101-8310, Japan
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Joshi S, Kar S, Kavdia M. Computational analysis of interactions of oxidative stress and tetrahydrobiopterin reveals instability in eNOS coupling. Microvasc Res 2017; 114:114-128. [PMID: 28729163 DOI: 10.1016/j.mvr.2017.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 07/11/2017] [Accepted: 07/11/2017] [Indexed: 01/30/2023]
Abstract
In cardiovascular and neurovascular diseases, an increase in oxidative stress and endothelial dysfunction has been reported. There is a reduction in tetrahydrobiopterin (BH4), which is a cofactor for the endothelial nitric oxide synthase (eNOS), resulting in eNOS uncoupling. Studies of the enhancement of BH4 availability have reported mixed results for improvement in endothelial dysfunction. Our understanding of the complex interactions of eNOS uncoupling, oxidative stress and BH4 availability is not complete and a quantitative understanding of these interactions is required. In the present study, we developed a computational model for eNOS uncoupling that considers the temporal changes in biopterin ratio in the oxidative stress conditions. Using the model, we studied the effects of cellular oxidative stress (Qsupcell) representing the non-eNOS based oxidative stress sources and BH4 synthesis (QBH4) on eNOS NO production and biopterin ratio (BH4/total biopterins (TBP)). Model results showed that oxidative stress levels from 0.01 to 1nM·s-1 did not affect eNOS NO production and eNOS remained in coupled state. When the Qsupcell increased above 1nM·s-1, the eNOS coupling and NO production transitioned to an oscillatory state. Oxidative stress levels dynamically changed the biopterin ratio. When Qsupcell increased from 1 to 100nM·s-1, the endothelial cell NO production, TBP levels and biopterin ratio reduced significantly from 26.5 to 2nM·s-1, 3.75 to 0.002μM and 0.99 to 0.25, respectively. For an increase in BH4 synthesis, the improvement in NO production rate and BH4 levels were dependent on the extent of cellular oxidative stress. However, a 10-fold increase in QBH4 at higher oxidative stresses did not restore the NO-production rate and the biopterin ratio. Our mechanistic analysis reveals that a combination of enhancing tetrahydrobiopterin level with a reduction in cellular oxidative stress may result in significant improvement in endothelial dysfunction.
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Affiliation(s)
- Sheetal Joshi
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48202, USA
| | - Saptarshi Kar
- Engineering Computational Biology Group, University of Western Australia, Crawley, WA 6009, Australia
| | - Mahendra Kavdia
- Department of Biomedical Engineering, Wayne State University, Detroit, MI 48202, USA.
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Potje SR, Chen Z, Oliveira SDS, Bendhack LM, da Silva RS, Bonini MG, Antoniali C, Minshall RD. Nitric oxide donor [Ru(terpy)(bdq)NO] 3+ induces uncoupling and phosphorylation of endothelial nitric oxide synthase promoting oxidant production. Free Radic Biol Med 2017; 112:587-596. [PMID: 28899725 PMCID: PMC5647835 DOI: 10.1016/j.freeradbiomed.2017.09.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 02/07/2023]
Abstract
[Ru(terpy)(bdq)NO]3+ (TERPY) is a nitric oxide (NO) donor that promotes relaxation of the mesenteric artery and aorta in rats. We sought to investigate whether it acts as both an NO donor and endothelial NO synthase (eNOS) activator, as shown previously for nitroglycerin. Human umbilical vein endothelial cells (HUVECs) and human embryonic kidney 293 cells transfected with empty vector (HEK) or eNOS cDNA (HEK-eNOS) were treated with TERPY (1µM) for different lengths of time. eNOS expression, dimerization, and Ser1177 phosphorylation, caveolin-1 (Cav-1) oligomerization, Cav-1 Tyr14 phosphorylation were evaluated by Western blotting. Studies also assessed the production of reactive oxygen/nitrogen species (ROS/RNS) in HUVECs and HEK-eNOS cells. In HEK cells devoid of eNOS, TERPY released NO without additional stimulus indicating that is an NO donor. Moreover, in HEK-eNOS cells, TERPY-induced NO production that was blocked by L-NAME. In addition, TERPY increased ROS and ONOO- production which were blocked by more than 80% by BH4 (essential eNOS co-factor) and eNOS siRNA. These results suggest that TERPY-induced ROS and ONOO- production were originated from eNOS. HUVECs stimulated with TERPY showed increased eNOS Ser1177 and Cav-1 Tyr14 phosphorylation, and decreased eNOS dimerization, Cav-1 oligomerization, and Cav-1/eNOS interaction after 20min. It suggests that TERPY induces eNOS hyperactivation and uncoupling by disrupting Cav-1/eNOS interaction and depleting BH4. Endothelium-dependent vasodilation in response to NO donor TERPY is associated with eNOS activation and uncoupling, and thereby appears to be mediated, at least in part, via eNOS-dependent ROS/RNS production.
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Affiliation(s)
- Simone R Potje
- Programa Multicêntrico de Pós-graduação em Ciências Fisiológicas, Department of Basic Sciences, School of Dentistry, São Paulo State University, Araçatuba, Brazil; Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL, USA
| | - Zhenlong Chen
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL, USA
| | | | - Lusiane M Bendhack
- Department of Physics and Chemistry, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, Brazil
| | - Roberto S da Silva
- Department of Physics and Chemistry, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, Brazil
| | - Marcelo G Bonini
- Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Cristina Antoniali
- Programa Multicêntrico de Pós-graduação em Ciências Fisiológicas, Department of Basic Sciences, School of Dentistry, São Paulo State University, Araçatuba, Brazil.
| | - Richard D Minshall
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL, USA; Department of Pharmacology, University of Illinois at Chicago, Chicago, IL, USA.
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Dong X, Cai R, Sun J, Huang R, Wang P, Sun H, Tian S, Wang S. Diabetes as a risk factor for acute coronary syndrome in women compared with men: a meta-analysis, including 10 856 279 individuals and 106 703 acute coronary syndrome events. Diabetes Metab Res Rev 2017; 33. [PMID: 28103417 DOI: 10.1002/dmrr.2887] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 09/17/2016] [Accepted: 01/16/2017] [Indexed: 11/11/2022]
Abstract
BACKGROUND Diabetes mellitus is a significant cause of death and disability worldwide and is a strong risk factor for acute coronary syndrome (ACS). Whether diabetes confers the same excess risk of ACS in both sexes is unknown. Therefore, we undertook a meta-analysis to estimate the relative risk (RR) for ACS associated with diabetes in men and women. METHODS We systematically searched PubMed, Embase, and Cochrane Library databases for both case-control and cohort studies published between January 1, 1966, and January 1, 2015. Studies were included if they reported sex-specific estimates of the RR, hazard ratio, or odds ratio for the association between diabetes and ACS. We pooled the sex-specific RR and the ratio between women and men using a random-effect model with inverse-variance weighting. RESULTS We included 9 case-control and 10 cohort studies with data for 10 856 279 individuals and at least 106 703 fatal and nonfatal ACS events. The pooled maximum-adjusted RR of ACS associated with diabetes was 2.46 (95% CI, 1.92-3.17) in women and 1.68 (95% CI, 1.39-2.04) in men. In patients with diabetes compared with those without diabetes, women had a significantly greater risk of ACS-the pooled women-to-men RR and the ratio of relative risks was 1.38 (95% CI, 1.25-1.52; P < .001), with no evidence of publication bias. CONCLUSIONS The excess risk of ACS associated with diabetes is significantly higher in women than in men. This finding may be explained by more adverse cardiovascular risk profiles and suggests that further work is needed to clarify the relevant biological, behavioural, and social mechanisms.
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Affiliation(s)
- Xue Dong
- Department of Endocrinology, Affiliated ZhongDa Hospital of Southeast University, Medical School of Southeast University, Nanjing, China
| | - Rongrong Cai
- Medical School of Southeast University, Nanjing, China
| | - Jie Sun
- Medical School of Southeast University, Nanjing, China
| | - Rong Huang
- Medical School of Southeast University, Nanjing, China
| | - Pin Wang
- Medical School of Southeast University, Nanjing, China
| | - Haixia Sun
- Medical School of Southeast University, Nanjing, China
| | - Sai Tian
- Medical School of Southeast University, Nanjing, China
| | - Shaohua Wang
- Department of Endocrinology, Affiliated ZhongDa Hospital of Southeast University, Medical School of Southeast University, Nanjing, China
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High-Intensity Exercise Reduces Cardiac Fibrosis and Hypertrophy but Does Not Restore the Nitroso-Redox Imbalance in Diabetic Cardiomyopathy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:7921363. [PMID: 28698769 PMCID: PMC5494101 DOI: 10.1155/2017/7921363] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Revised: 04/18/2017] [Accepted: 04/27/2017] [Indexed: 01/25/2023]
Abstract
Diabetic cardiomyopathy refers to the manifestations in the heart as a result of altered glucose homeostasis, reflected as fibrosis, cellular hypertrophy, increased oxidative stress, and apoptosis, leading to ventricular dysfunction. Since physical exercise has been indicated as cardioprotective, we tested the hypothesis that high-intensity exercise training could reverse the cardiac maladaptations produced by diabetes. For this, diabetes was induced in rats by a single dose of alloxan. Diabetic rats were randomly assigned to a sedentary group or submitted to a program of exercise on a treadmill for 4 weeks at 80% of maximal performance. Another group of normoglycemic rats was used as control. Diabetic rat hearts presented cardiomyocyte hypertrophy and interstitial fibrosis. Chronic exercise reduced both parameters but increased apoptosis. Diabetes increased the myocardial levels of the mRNA and proteins of NADPH oxidases NOX2 and NOX4. These altered levels were not reduced by exercise. Diabetes also increased the level of uncoupled endothelial nitric oxide synthase (eNOS) that was not reversed by exercise. Finally, diabetic rats showed a lower degree of phosphorylated phospholamban and reduced levels of SERCA2 that were not restored by high-intensity exercise. These results suggest that high-intensity chronic exercise was able to reverse remodeling in the diabetic heart but was unable to restore the nitroso-redox imbalance imposed by diabetes.
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McCarty MF. Supplementation with Phycocyanobilin, Citrulline, Taurine, and Supranutritional Doses of Folic Acid and Biotin-Potential for Preventing or Slowing the Progression of Diabetic Complications. Healthcare (Basel) 2017; 5:E15. [PMID: 28335416 PMCID: PMC5371921 DOI: 10.3390/healthcare5010015] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 02/23/2017] [Accepted: 03/06/2017] [Indexed: 02/07/2023] Open
Abstract
Oxidative stress, the resulting uncoupling of endothelial nitric oxide synthase (eNOS), and loss of nitric oxide (NO) bioactivity, are key mediators of the vascular and microvascular complications of diabetes. Much of this oxidative stress arises from up-regulated nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity. Phycocyanobilin (PhyCB), the light-harvesting chromophore in edible cyanobacteria such as spirulina, is a biliverdin derivative that shares the ability of free bilirubin to inhibit certain isoforms of NADPH oxidase. Epidemiological studies reveal that diabetics with relatively elevated serum bilirubin are less likely to develop coronary disease or microvascular complications; this may reflect the ability of bilirubin to ward off these complications via inhibition of NADPH oxidase. Oral PhyCB may likewise have potential in this regard, and has been shown to protect diabetic mice from glomerulosclerosis. With respect to oxidant-mediated uncoupling of eNOS, high-dose folate can help to reverse this by modulating the oxidation status of the eNOS cofactor tetrahydrobiopterin (BH4). Oxidation of BH4 yields dihydrobiopterin (BH2), which competes with BH4 for binding to eNOS and promotes its uncoupling. The reduced intracellular metabolites of folate have versatile oxidant-scavenging activity that can prevent oxidation of BH4; concurrently, these metabolites promote induction of dihydrofolate reductase, which functions to reconvert BH2 to BH4, and hence alleviate the uncoupling of eNOS. The arginine metabolite asymmetric dimethylarginine (ADMA), typically elevated in diabetics, also uncouples eNOS by competitively inhibiting binding of arginine to eNOS; this effect is exacerbated by the increased expression of arginase that accompanies diabetes. These effects can be countered via supplementation with citrulline, which efficiently enhances tissue levels of arginine. With respect to the loss of NO bioactivity that contributes to diabetic complications, high dose biotin has the potential to "pinch hit" for diminished NO by direct activation of soluble guanylate cyclase (sGC). High-dose biotin also may aid glycemic control via modulatory effects on enzyme induction in hepatocytes and pancreatic beta cells. Taurine, which suppresses diabetic complications in rodents, has the potential to reverse the inactivating impact of oxidative stress on sGC by boosting synthesis of hydrogen sulfide. Hence, it is proposed that concurrent administration of PhyCB, citrulline, taurine, and supranutritional doses of folate and biotin may have considerable potential for prevention and control of diabetic complications. Such a regimen could also be complemented with antioxidants such as lipoic acid, N-acetylcysteine, and melatonin-that boost cellular expression of antioxidant enzymes and glutathione-as well as astaxanthin, zinc, and glycine. The development of appropriate functional foods might make it feasible for patients to use complex nutraceutical regimens of the sort suggested here.
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Affiliation(s)
- Mark F McCarty
- Catalytic Longevity, 7831 Rush Rose Dr., Apt. 316, Carlsbad, CA 92009, USA.
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50
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Bailey J, Shaw A, Fischer R, Ryan BJ, Kessler BM, McCullagh J, Wade-Martins R, Channon KM, Crabtree MJ. A novel role for endothelial tetrahydrobiopterin in mitochondrial redox balance. Free Radic Biol Med 2017; 104:214-225. [PMID: 28104455 PMCID: PMC5338462 DOI: 10.1016/j.freeradbiomed.2017.01.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 01/04/2017] [Accepted: 01/06/2017] [Indexed: 02/07/2023]
Abstract
The redox co-factor tetrahydrobiopterin (BH4) regulates nitric oxide (NO) and reactive oxygen species (ROS) production by endothelial NOS (eNOS) and is an important redox-dependent signalling molecule in the endothelium. Loss of endothelial BH4 is observed in cardiovascular disease (CVD) states and results in decreased NO and increased superoxide (O2-) generation via eNOS uncoupling. Genetic mouse models of augmented endothelial BH4 synthesis have shown proof of concept that endothelial BH4 can alter CVD pathogenesis. However, clinical trials of BH4 therapy in vascular disease have been limited by systemic oxidation, highlighting the need to explore the wider roles of BH4 to find novel therapeutic targets. In this study, we aimed to elucidate the effects of BH4 deficiency on mitochondrial function and bioenergetics using targeted knockdown of the BH4 synthetic enzyme, GTP Cyclohydrolase I (GTPCH). Knockdown of GTPCH by >90% led to marked loss of cellular BH4 and a striking induction of O2- generation in the mitochondria of murine endothelial cells. This effect was likewise observed in BH4-depleted fibroblasts devoid of NOS, indicating a novel NOS-independent role for BH4 in mitochondrial redox signalling. Moreover, this BH4-dependent, mitochondria-derived ROS further oxidised mitochondrial BH4, concomitant with changes in the thioredoxin and glutathione antioxidant pathways. These changes were accompanied by a modest increase in mitochondrial size, mildly attenuated basal respiratory function, and marked changes in the mitochondrial proteome and cellular metabolome, including the accumulation of the TCA intermediate succinate. Taken together, these data reveal a novel NOS-independent role for BH4 in the regulation of mitochondrial redox signalling and bioenergetic metabolism.
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Affiliation(s)
- Jade Bailey
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, United Kingdom
| | - Andrew Shaw
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, United Kingdom
| | - Roman Fischer
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7FZ, United Kingdom
| | - Brent J Ryan
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, South Parks Road, Oxford OX1 3QX, United Kingdom
| | - Benedikt M Kessler
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7FZ, United Kingdom
| | - James McCullagh
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Richard Wade-Martins
- Oxford Parkinson's Disease Centre, Department of Physiology, Anatomy and Genetics, South Parks Road, Oxford OX1 3QX, United Kingdom
| | - Keith M Channon
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, United Kingdom.
| | - Mark J Crabtree
- BHF Centre of Research Excellence, Division of Cardiovascular Medicine, Radcliffe Department of Medicine, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, United Kingdom
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