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Devasia AG, Shanmugham M, Ramasamy A, Bellanger S, Parry LJ, Leo CH. Therapeutic potential of relaxin or relaxin mimetics in managing cardiovascular complications of diabetes. Biochem Pharmacol 2024; 229:116507. [PMID: 39182735 DOI: 10.1016/j.bcp.2024.116507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 08/20/2024] [Accepted: 08/22/2024] [Indexed: 08/27/2024]
Abstract
Diabetes mellitus is a metabolic disease with an escalating global prevalence. Despite the abundance and relative efficacies of current therapeutic approaches, they primarily focus on attaining the intended glycaemic targets, but patients ultimately still suffer from various diabetes-associated complications such as retinopathy, nephropathy, cardiomyopathy, and atherosclerosis. There is a need to explore innovative and effective diabetic treatment strategies that not only address the condition itself but also combat its complications. One promising option is the reproductive hormone relaxin, an endogenous ligand of the RXFP1 receptor. Relaxin is known to exert beneficial actions on the cardiovascular system through its vasoprotective, anti-inflammatory and anti-fibrotic effects. Nevertheless, the native relaxin peptide exhibits a short biological half-life, limiting its therapeutic potential. Recently, several relaxin mimetics and innovative delivery technologies have been developed to extend its biological half-life and efficacy. The current review provides a comprehensive landscape of the cardiovascular effects of relaxin, focusing on its potential therapeutic applications in managing complications associated with diabetes. The latest advancements in the development of relaxin mimetics and delivery methods for the treatment of cardiometabolic disorders are also discussed.
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Affiliation(s)
- Arun George Devasia
- Science, Math & Technology, Singapore University of Technology & Design, Singapore 487372, Singapore; Genome Institute of Singapore (GIS), Agency for Science Technology and Research (A*STAR), 60 Biopolis Street, Genome, Singapore 138672, Singapore
| | - Meyammai Shanmugham
- Science, Math & Technology, Singapore University of Technology & Design, Singapore 487372, Singapore; A*STAR Skin Research Labs (A*SRL), Skin Research Institute of Singapore (SRIS), Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, #06-06 Immunos, Singapore 138648, Singapore
| | - Adaikalavan Ramasamy
- Genome Institute of Singapore (GIS), Agency for Science Technology and Research (A*STAR), 60 Biopolis Street, Genome, Singapore 138672, Singapore
| | - Sophie Bellanger
- A*STAR Skin Research Labs (A*SRL), Skin Research Institute of Singapore (SRIS), Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, #06-06 Immunos, Singapore 138648, Singapore
| | - Laura J Parry
- School of Biological Sciences, The University of Adelaide, Adelaide, SA, Australia
| | - Chen Huei Leo
- Department of Biomedical Engineering, College of Design & Engineering, National University of Singapore, Singapore 117576, Singapore.
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Dou B, Zhu Y, Sun M, Wang L, Tang Y, Tian S, Wang F. Mechanisms of Flavonoids and Their Derivatives in Endothelial Dysfunction Induced by Oxidative Stress in Diabetes. Molecules 2024; 29:3265. [PMID: 39064844 PMCID: PMC11279171 DOI: 10.3390/molecules29143265] [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: 06/07/2024] [Revised: 07/02/2024] [Accepted: 07/05/2024] [Indexed: 07/28/2024] Open
Abstract
Diabetic complications pose a significant threat to life and have a negative impact on quality of life in individuals with diabetes. Among the various factors contributing to the development of these complications, endothelial dysfunction plays a key role. The main mechanism underlying endothelial dysfunction in diabetes is oxidative stress, which adversely affects the production and availability of nitric oxide (NO). Flavonoids, a group of phenolic compounds found in vegetables, fruits, and fungi, exhibit strong antioxidant and anti-inflammatory properties. Several studies have provided evidence to suggest that flavonoids have a protective effect on diabetic complications. This review focuses on the imbalance between reactive oxygen species and the antioxidant system, as well as the changes in endothelial factors in diabetes. Furthermore, we summarize the protective mechanisms of flavonoids and their derivatives on endothelial dysfunction in diabetes by alleviating oxidative stress and modulating other signaling pathways. Although several studies underline the positive influence of flavonoids and their derivatives on endothelial dysfunction induced by oxidative stress in diabetes, numerous aspects still require clarification, such as optimal consumption levels, bioavailability, and side effects. Consequently, further investigations are necessary to enhance our understanding of the therapeutic potential of flavonoids and their derivatives in the treatment of diabetic complications.
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Affiliation(s)
| | | | | | | | | | | | - Furong Wang
- College of Traditional Chinese Medicine, Shandong University of Traditional Chinese Medicine, Jinan 250300, China
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Shanmugham M, Devasia AG, Chin YL, Cheong KH, Ong ES, Bellanger S, Ramasamy A, Leo CH. Time-dependent specific molecular signatures of inflammation and remodelling are associated with trimethylamine-N-oxide (TMAO)-induced endothelial cell dysfunction. Sci Rep 2023; 13:20303. [PMID: 37985702 PMCID: PMC10661905 DOI: 10.1038/s41598-023-46820-7] [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: 06/06/2023] [Accepted: 11/06/2023] [Indexed: 11/22/2023] Open
Abstract
Endothelial dysfunction is a critical initiating factor contributing to cardiovascular diseases, involving the gut microbiome-derived metabolite trimethylamine N-oxide (TMAO). This study aims to clarify the time-dependent molecular pathways by which TMAO mediates endothelial dysfunction through transcriptomics and metabolomics analyses in human microvascular endothelial cells (HMEC-1). Cell viability and reactive oxygen species (ROS) generation were also evaluated. TMAO treatment for either 24H or 48H induces reduced cell viability and enhanced oxidative stress. Interestingly, the molecular signatures were distinct between the two time-points. Specifically, few Gene Ontology biological processes (BPs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were modulated after a short (24H) compared to a long (48H) treatment. However, the KEGG signalling pathways namely "tumour necrosis factor (TNF)" and "cytokine-cytokine receptor interaction" were downregulated at 24H but activated at 48H. In addition, at 48H, BPs linked to inflammatory phenotypes were activated (confirming KEGG results), while BPs linked to extracellular matrix (ECM) structural organisation, endothelial cell proliferation, and collagen metabolism were repressed. Lastly, metabolic profiling showed that arachidonic acid, prostaglandins, and palmitic acid were enriched at 48H. This study demonstrates that TMAO induces distinct time-dependent molecular signatures involving inflammation and remodelling pathways, while pathways such as oxidative stress are also modulated, but in a non-time-dependent manner.
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Affiliation(s)
- Meyammai Shanmugham
- Science, Math & Technology, Singapore University of Technology & Design, 8 Somapah Road, Singapore, 487372, Republic of Singapore
- A*STAR Skin Research Labs (A*SRL), Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, #06-06 Immunos, Singapore, 138648, Republic of Singapore
| | - Arun George Devasia
- Science, Math & Technology, Singapore University of Technology & Design, 8 Somapah Road, Singapore, 487372, Republic of Singapore
- Genome Institute of Singapore (GIS), Agency for Science Technology and Research (A*STAR), 60 Biopolis Street, Genome, Singapore, 138672, Republic of Singapore
| | - Yu Ling Chin
- Science, Math & Technology, Singapore University of Technology & Design, 8 Somapah Road, Singapore, 487372, Republic of Singapore
| | - Kang Hao Cheong
- Science, Math & Technology, Singapore University of Technology & Design, 8 Somapah Road, Singapore, 487372, Republic of Singapore
| | - Eng Shi Ong
- Science, Math & Technology, Singapore University of Technology & Design, 8 Somapah Road, Singapore, 487372, Republic of Singapore
| | - Sophie Bellanger
- A*STAR Skin Research Labs (A*SRL), Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, #06-06 Immunos, Singapore, 138648, Republic of Singapore
| | - Adaikalavan Ramasamy
- Genome Institute of Singapore (GIS), Agency for Science Technology and Research (A*STAR), 60 Biopolis Street, Genome, Singapore, 138672, Republic of Singapore
| | - Chen Huei Leo
- Science, Math & Technology, Singapore University of Technology & Design, 8 Somapah Road, Singapore, 487372, Republic of Singapore.
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Leo CH, Ong ES. Recent advances in the combination of organic solvent-free extraction, chemical standardization, antioxidant assay, and cell culture metabolomics for functional food and its by-product. Crit Rev Food Sci Nutr 2023:1-15. [PMID: 37574586 DOI: 10.1080/10408398.2023.2245040] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Functional foods and their by-products contain a wide range of bioactive components with an array of health benefits and were proposed to improve public health, well-being, and others. To achieve a circular economy, the processing and extraction of flavonoids, phenolic compounds, and others from functional food and agri-food wastes will require the use of environmentally friendly, sustainable, and a low-cost solution. Extraction methods that can eliminate the use of organic solvents, suitable for use in the laboratory and production of extracts will be covered. This will include subcritical water extraction (SBE), pressurized hot water extraction (PHWE), supercritical fluid extraction (SFE), and others. Based on the selected analytical methods, the determination of the marker or bioactive compounds and chemical fingerprints will provide the control measures to identify the batch-to-batch variation of the composition of the functional food products obtained. The combination of chemical standardization with antioxidant assay, such as DPPH and ABTS+ will provide further information on the quality of the extracts. Lastly, to ascertain the biological and physiological relevance of the antioxidant properties of the target sample, treatment of the antioxidant compounds or extracts was carried out using cellular models, and validated using other experimental endpoints, such as metabolomics.
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Affiliation(s)
- Chen Huei Leo
- Department of Science, Math & Technology, Singapore University of Technology & Design, Singapore, Singapore
- Center for Healthcare Education, Entrepreneurship and Research (CHEERS), Singapore University of Technology & Design, Singapore, Singapore
| | - Eng Shi Ong
- Department of Science, Math & Technology, Singapore University of Technology & Design, Singapore, Singapore
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Shanmugham M, Bellanger S, Leo CH. Gut-Derived Metabolite, Trimethylamine-N-oxide (TMAO) in Cardio-Metabolic Diseases: Detection, Mechanism, and Potential Therapeutics. Pharmaceuticals (Basel) 2023; 16:ph16040504. [PMID: 37111261 PMCID: PMC10142468 DOI: 10.3390/ph16040504] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/17/2023] [Accepted: 03/23/2023] [Indexed: 03/30/2023] Open
Abstract
Trimethylamine N-oxide (TMAO) is a biologically active gut microbiome-derived dietary metabolite. Recent studies have shown that high circulating plasma TMAO levels are closely associated with diseases such as atherosclerosis and hypertension, and metabolic disorders such as diabetes and hyperlipidemia, contributing to endothelial dysfunction. There is a growing interest to understand the mechanisms underlying TMAO-induced endothelial dysfunction in cardio-metabolic diseases. Endothelial dysfunction mediated by TMAO is mainly driven by inflammation and oxidative stress, which includes: (1) activation of foam cells; (2) upregulation of cytokines and adhesion molecules; (3) increased production of reactive oxygen species (ROS); (4) platelet hyperreactivity; and (5) reduced vascular tone. In this review, we summarize the potential roles of TMAO in inducing endothelial dysfunction and the mechanisms leading to the pathogenesis and progression of associated disease conditions. We also discuss the potential therapeutic strategies for the treatment of TMAO-induced endothelial dysfunction in cardio-metabolic diseases.
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Affiliation(s)
- Meyammai Shanmugham
- Science, Math & Technology, Singapore University of Technology & Design, 8 Somapah Road, Singapore 487372, Singapore
| | - Sophie Bellanger
- A*STAR Skin Research Labs, Agency for Science, Technology and Research, Singapore 138648, Singapore
| | - Chen Huei Leo
- Science, Math & Technology, Singapore University of Technology & Design, 8 Somapah Road, Singapore 487372, Singapore
- Correspondence: ; Tel.: +65-6434-8213
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Leo CH, Foo SY, Tan JCW, Tan UX, Chua CK, Ong ES. Green Extraction of Orange Peel Waste Reduces TNFα-Induced Vascular Inflammation and Endothelial Dysfunction. Antioxidants (Basel) 2022; 11:antiox11091768. [PMID: 36139842 PMCID: PMC9495443 DOI: 10.3390/antiox11091768] [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: 07/20/2022] [Revised: 08/30/2022] [Accepted: 09/02/2022] [Indexed: 11/16/2022] Open
Abstract
Orange peel waste (OPW) is known to contain an abundant amount of polyphenols compounds such as flavonoids, well-reported for their antioxidant and anti-inflammatory properties. While OPW is generally regarded as a food waste, the opportunity to extract bioactive compounds from these “wastes” arises due to their abundance, allowing the investigation of their potential effects on endothelial cells. Hence, this study aims to use a green extraction method and pressurized hot water extraction (PHWE) to extract bioactive compounds from OPW. Liquid chromatography with UV detection (LC/UV) and liquid chromatography mass spectrometry (LC/MS) were subsequently used to identify the bioactive compounds present. Through the optimization of the extraction temperature for PHWE, our results demonstrated that extraction temperatures of 60 °C and 80 °C yield distinct bioactive compounds and resulted in better antioxidant capacity compared to other extraction temperatures or organic solvent extraction. Despite having similar antioxidant capacity, their effects on endothelial cells were distinct. Specifically, treatment of endothelial cells with 60 °C OPW extracts inhibited TNFα-induced vascular inflammation and endothelial dysfunction in vitro, suggesting that OPW possess vasoprotective effects likely mediated by anti-inflammatory effects.
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Affiliation(s)
- Chen Huei Leo
- Science, Math & Technology, Singapore University of Technology & Design, Singapore 487372, Singapore
- Correspondence: ; Tel.: +65-6434-8213
| | - Su Yi Foo
- Science, Math & Technology, Singapore University of Technology & Design, Singapore 487372, Singapore
| | - Joseph Choon Wee Tan
- Science, Math & Technology, Singapore University of Technology & Design, Singapore 487372, Singapore
| | - U-Xuan Tan
- Pillar of Engineering Product Development, Singapore University of Technology & Design, Singapore 487372, Singapore
| | - Chee Kai Chua
- Pillar of Engineering Product Development, Singapore University of Technology & Design, Singapore 487372, Singapore
| | - Eng Shi Ong
- Science, Math & Technology, Singapore University of Technology & Design, Singapore 487372, Singapore
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Fan Gaskin JC, Kong RCK, Shah MH, Edgley AJ, Peshavariya HM, Chan EC. Inhibitory Effects of 3',4'-Dihydroxyflavonol in a Mouse Model of Glaucoma Filtration Surgery and TGFβ1-Induced Responses in Human Tenon's Fibroblasts. Transl Vis Sci Technol 2022; 11:18. [PMID: 35980669 PMCID: PMC9404366 DOI: 10.1167/tvst.11.8.18] [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] [Indexed: 11/24/2022] Open
Abstract
Purpose Cytotoxic agents such as mitomycin C (MMC) are part of the mainstay treatment for limiting subconjunctival scarring following glaucoma filtration surgery (GFS). However, a safer antifibrotic therapy is clinically needed. The anti-scarring properties of 3′,4′-dihydroxyflavonol (DiOHF) were evaluated in a mouse model of GFS and in cultured human Tenon's fibroblasts (HTFs). Methods GFS was performed in C57BL/6 mice receiving daily intraperitoneal injections of DiOHF or vehicle or a single intraoperative injection of MMC. Eyes were harvested on day 14 for assessment of collagen deposition, expression of alpha-smooth muscle actin (α-SMA), cluster of differentiation 31 (CD31), and 4-hydroxy-2-nonenal (4HNE) in the conjunctiva/Tenon's layer. The inhibitory effects of DiOHF on transforming growth factor β (TGFβ)-induced responses were also assessed in HTFs. Results Treatment with DiOHF demonstrated a reduction in collagen deposition at the GFS site compared to vehicle-treated mice. The degree of 4HNE-positive fluorescence was significantly reduced in DiOHF-treated eyes compared to the other groups, indicating a decrease in oxidative stress. A reduction in expression of α-SMA and CD31 was seen in DiOHF-treated conjunctiva compared to those treated with vehicle. Concordant results were demonstrated in cultured HTFs in vitro. Furthermore, treatment of cultured HTFs with DiOHF also displayed a reduction in the proliferation, migration, and contractility of HTFs. Conclusions Treatment with DiOHF reduces scarring and angiogenesis in the conjunctiva of mice with GFS at a level comparable to MMC. The reduction in oxidative stress suggests that DiOHF may suppress scarring via different mechanisms from MMC. Translational Relevance DiOHF may be a safer and superior wound modulating agent than conventional antifibrotic therapy in GFS.
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Affiliation(s)
- Jennifer C Fan Gaskin
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Glaucoma Investigation and Research Unit, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia
| | - Roy C K Kong
- Department of Medicine, St. Vincent's Hospital, University of Melbourne, Melbourne, Australia
| | - Manisha H Shah
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia
| | - Amanda J Edgley
- Department of Medicine, St. Vincent's Hospital, University of Melbourne, Melbourne, Australia
| | - Hitesh M Peshavariya
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia
| | - Elsa C Chan
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, Australia.,Department of Medicine, St. Vincent's Hospital, University of Melbourne, Melbourne, Australia
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Kompa AR, Khong FL, Zhang Y, Nguyen C, Edgley AJ, Woodman OL, McLachlan G, Kelly DJ. NP202 treatment improves left ventricular systolic function and attenuates pathological remodelling following chronic myocardial infarction. Life Sci 2022; 289:120220. [PMID: 34902438 DOI: 10.1016/j.lfs.2021.120220] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 11/19/2022]
Abstract
AIMS Myocardial injury is a major contributor to left ventricular (LV) remodelling activating neurohormonal and inflammatory processes that create an environment of enhanced oxidative stress. This results in geometric and structural alterations leading to reduced LV systolic function. In this study we evaluated the efficacy of NP202, a synthetic flavonol, on cardiac remodelling in a chronic model of myocardial infarction (MI). MAIN METHODS A rat model of chronic MI was induced by permanent surgical ligation of the coronary artery. NP202 treatment was commenced 2 days post-MI for 6 weeks at different doses (1, 10 and 20 mg/kg/day) to determine efficacy. Cardiac function was assessed by echocardiography prior to treatment and at week 6, and pressure-volume measurements were performed prior to tissue collection. Tissues were analysed for changes in fibrotic and inflammatory markers using immunohistochemistry and gene expression analysis. KEY FINDINGS Rats treated with NP202 demonstrated improved LV systolic function and LV geometry compared to vehicle treated animals. Furthermore, measures of hypertrophy and interstitial fibrosis were attenuated in the non-infarct region of the myocardium with NP202 at the higher dose of 20 mg/kg (P < 0.05). At the tissue level, NP202 reduced monocyte chemoattractant protein-1 expression (P < 0.05) and tended to attenuate active caspase-3 expression to similar levels observed in sham animals (P = 0.075). SIGNIFICANCE Improved LV function and structural changes observed with NP202 may be mediated through inhibition of inflammatory and apoptotic processes in the MI setting. NP202 could therefore prove a useful addition to standard therapy in patients with post-MI LV dysfunction.
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Affiliation(s)
- Andrew R Kompa
- The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, VIC, Australia.
| | - Fay L Khong
- The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, VIC, Australia
| | - Yuan Zhang
- The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, VIC, Australia
| | - Cindy Nguyen
- The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, VIC, Australia
| | - Amanda J Edgley
- The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, VIC, Australia
| | - Owen L Woodman
- Monash University, Monash Institute of Pharmaceutical Sciences, Parkville, VIC, Australia
| | | | - Darren J Kelly
- The University of Melbourne, Department of Medicine, St Vincent's Hospital, Fitzroy, VIC, Australia
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Pressurized Hot Water Extraction of Okra Seeds Reveals Antioxidant, Antidiabetic and Vasoprotective Activities. PLANTS 2021; 10:plants10081645. [PMID: 34451690 PMCID: PMC8399463 DOI: 10.3390/plants10081645] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/06/2021] [Accepted: 08/07/2021] [Indexed: 12/19/2022]
Abstract
Abelmoschus esculentus L. Moench (okra) is a commonly consumed vegetable that consists of the seeds and peel component which are rich in polyphenolic compounds. The aim of this study is to utilize pressurized hot water extraction (PHWE) for the extraction of bioactive phytochemicals from different parts of okra. A single step PHWE was performed at various temperatures (60 °C, 80 °C, 100 °C and 120 °C) to determine which extraction temperature exhibits the optimum phytochemical profile, antioxidant and antidiabetic activities. The optimum temperature for PHWE extraction was determined at 80 °C and the biological activities of the different parts of okra (Inner Skin, Outer Skin and Seeds) were characterized using antioxidant (DPPH and ABTS), α-glucosidase and vasoprotective assays. Using PHWE, the different parts of okra displayed distinct phytochemical profiles, which consist of primarily polyphenolic compounds. The okra Seeds were shown to have the most antioxidant capacity and antidiabetic effects compared to other okra parts, likely to be attributed to their higher levels of polyphenolic compounds. Similarly, okra Seeds also reduced vascular inflammation by downregulating TNFα-stimulated VCAM-1 and SELE expression. Furthermore, metabolite profiling by LC/MS also provided evidence of the cytoprotective effect of okra Seeds in endothelial cells. Therefore, the use of PHWE may be an alternative approach for the environmentally friendly extraction and evaluation of plant extracts for functional food applications.
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3',4'-Dihydroxyflavonol Modulates the Cell Cycle in Cancer Cells: Implication as a Potential Combination Drug in Osteosarcoma. Pharmaceuticals (Basel) 2021; 14:ph14070640. [PMID: 34358066 PMCID: PMC8308859 DOI: 10.3390/ph14070640] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 06/29/2021] [Accepted: 06/30/2021] [Indexed: 12/29/2022] Open
Abstract
New agents are demanded to increase the therapeutic options for osteosarcoma (OS). Although OS is the most common bone cancer in children and adolescents, it is considered a rare disorder. Therefore, finding adjuvant drugs has potential to advance therapy for this disease. In this study, 3′,4′-dihydroxyflavonol (DiOHF) was investigated to assess the effects in OS cellular models in combination with doxorubicin (Dox). MG-63 and U2OS human OS cells were exposed to DiOHF and Dox and tested for cell viability and growth. To elucidate the inhibitory effects of DiOHF, additional studies were conducted to assess apoptosis and cell cycle distribution, gene expression quantification of cell cycle regulators, and cytokinesis-block cytome assay to determine nuclear division rate. DiOHF decreased OS cell growth and viability in a concentration-dependent manner. Its combination with Dox enabled Dox dose reduction in both cell lines, with synergistic interactions in U2OS cells. Although no significant apoptotic effects were detected at low concentrations, cytostatic effects were demonstrated in both cell lines. Incubation with DiOHF altered cell cycle dynamics and resulted in differential cyclin and cyclin-dependent kinase expression. Overall, this study presents an antiproliferative action of DiOHF in OS combination therapy via modulation of the cell cycle and nuclear division.
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Ong ES, Pek CJN, Tan JCW, Leo CH. Antioxidant and Cytoprotective Effect of Quinoa ( Chenopodium quinoa Willd.) with Pressurized Hot Water Extraction (PHWE). Antioxidants (Basel) 2020; 9:antiox9111110. [PMID: 33187302 PMCID: PMC7697190 DOI: 10.3390/antiox9111110] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/05/2020] [Accepted: 11/09/2020] [Indexed: 01/05/2023] Open
Abstract
Quinoa is widely noted for its nutritional value. The seed is the main edible part of the plant and exists in at least three different colors: white, red and black. This study utilized a pressurized hot water extraction (PHWE) for the extraction of phytochemicals from quinoa. Chemical fingerprints with LC/UV and LC/MS using a targeted approach and pattern recognition tools were used to evaluate the quinoa extracts. The antioxidant properties for various types of quinoa were evaluated using DPPH assay, ABTS assay and the cytoprotective effect of quinoa extracts were investigated in HMEC-1 cell line. Distinctive chemical profiles obtained from black and red quinoa were well correlated with the antioxidant activities and cytoprotective effects. The combination of PHWE, chemical standardization with LC/UV and LC/MS, pattern recognition tools and biological assay provided an approach for the evaluation and eventual production of quinoa extracts for functional food.
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Extra Virgin Olive Oil Phenols Dilate the Rat Mesenteric Artery by Activation of BK Ca2+ Channels in Smooth Muscle Cells. Molecules 2020; 25:molecules25112601. [PMID: 32503254 PMCID: PMC7321220 DOI: 10.3390/molecules25112601] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 05/15/2020] [Accepted: 05/29/2020] [Indexed: 12/25/2022] Open
Abstract
Accumulating evidence has shown the beneficial health effects of extra virgin olive oil (EVOO) consumption in reducing blood pressure and preventing the risk of developing hypertension. Some studies associate the hypotensive activity of EVOO to a minor component—the phenols. This study was designed to investigate the effects of EVOO phenols on the rat resistance mesenteric artery (MA) and to find out the possible vascular pathways involved. The experiments were carried out using a pressurized myograph, which allowed the effects of phenols on isolated MA to be tested under different conditions: (a) with endothelium removed; (b) with inhibition of nitric oxide synthase by Nω-Nitro-l-arginine methyl ester hydrochloride (l-NAME, 10−4 M) + Nω-Nitro-l-arginine (l-NNA, 10−4 M); (c) with inhibition of cyclooxygenase by indomethacin (10−5 M); (d) with inhibition of guanylate cyclase by 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ,10−5 M) or adenylate cyclase by 9-(Tetrahydro-2′-furyl)adenine (SQ, 10−5 M); (e) with depolarization by high potassium chloride (40 mM); and (f) with inhibition of the large conductance Ca2+–potassium channels (BKCa2+) with paxilline (10−5 M). EVOO phenols induce vasodilation of the endothelium, mediated by a direct effect on smooth muscle cells (SMC) by activation of BKCa2+ channels, an action by which phenols can regulate the vascular tone of the resistance artery. Phenols can be regarded as bioactive molecules that may contribute to the antihypertensive effects of EVOO.
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The Novel Small-molecule Annexin-A1 Mimetic, Compound 17b, Elicits Vasoprotective Actions in Streptozotocin-induced Diabetic Mice. Int J Mol Sci 2020; 21:ijms21041384. [PMID: 32085666 PMCID: PMC7073122 DOI: 10.3390/ijms21041384] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/14/2020] [Accepted: 02/16/2020] [Indexed: 12/11/2022] Open
Abstract
The formyl peptide receptor (FPR) family are a group of G-protein coupled receptors that play an important role in the regulation of inflammatory processes. It is well-established that activation of FPRs can have cardioprotective properties. Recently, more stable small-molecule FPR1/2 agonists have been described, including both Compound 17b (Cmpd17b) and Compound 43 (Cmpd43). Both agonists activate a range of signals downstream of FPR1/2 activation in human-engineered FPR-expressing cells, including ERK1/2 and Akt. Importantly, Cmpd17b (but not Cmpd43) favours bias away from intracellular Ca2+ mobilisation in this context, which has been associated with greater cardioprotection in response to Cmpd17b over Cmpd43. However, it is unknown whether these FPR agonists impact vascular physiology and/or elicit vasoprotective effects in the context of diabetes. First, we localized FPR1 and FPR2 receptors predominantly in vascular smooth muscle cells in the aortae of male C57BL/6 mice. We then analysed the vascular effects of Cmpd17b and Cmpd43 on the aorta using wire-myography. Cmpd17b but not Cmpd43 evoked a concentration-dependent relaxation of the mouse aorta. Removal of the endothelium or blockade of endothelium-derived relaxing factors using pharmacological inhibitors had no effect on Cmpd17b-evoked relaxation, demonstrating that its direct vasodilator actions were endothelium-independent. In aortae primed with elevated K+ concentration, increasing concentrations of CaCl2 evoked concentration-dependent contraction that is abolished by Cmpd17b, suggesting the involvement of the inhibition of Ca2+ mobilisation via voltage-gated calcium channels. Treatment with Cmpd17b for eight weeks reversed endothelial dysfunction in STZ-induced diabetic aorta through the upregulation of vasodilator prostanoids. Our data indicate that Cmpd17b is a direct endothelium-independent vasodilator, and a vasoprotective molecule in the context of diabetes.
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Qin CX, Anthonisz J, Leo CH, Kahlberg N, Velagic A, Li M, Jap E, Woodman OL, Parry LJ, Horowitz JD, Kemp-Harper BK, Ritchie RH. Nitric Oxide Resistance, Induced in the Myocardium by Diabetes, Is Circumvented by the Nitric Oxide Redox Sibling, Nitroxyl. Antioxid Redox Signal 2020; 32:60-77. [PMID: 31680536 DOI: 10.1089/ars.2018.7706] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Aim: Impairment of tissue responsiveness to exogenous and endogenous nitric oxide (NO•), known as NO• resistance, occurs in many cardiovascular disease states, prominently in diabetes and especially in the presence of marked hyperglycemia. In this study, we sought to determine in moderate and severe diabetes (i) whether NO• resistance also occurs in the myocardium, and (ii) whether the NO• redox sibling nitroxyl (HNO) circumvents this. Results: The spectrum of acute NO• effects (induced by diethylamine-NONOate), including vasodilation, and enhanced myocardial contraction and relaxation were impaired by moderately diabetic rats ([blood glucose] ∼20 mM). In contrast, acute HNO effects (induced by isopropylamine-NONOate) were preserved even in more severe diabetes ([blood glucose] >28 mM). Intriguingly, the positive inotropic effects of HNO were significantly enhanced in diabetic rat hearts. Further, progressive attenuation of soluble guanylyl cyclase (sGC) contribution to myocardial NO• responses occurred with increasing severity of diabetes. Nevertheless, activation of sGC by HNO remained intact in the myocardium. Innovation: Diabetes is associated with marked attenuation of vascular and myocardial effects of NO and NO donors, and this NO• resistance is circumvented by HNO, suggesting potential therapeutic utility for HNO donors in cardiovascular emergencies in diabetics. Conclusion: These results provide the first evidence that NO• resistance occurs in diabetic hearts, and that HNO largely circumvents this problem. Further, the positive inotropic and lusitropic effects of HNO are enhanced in a severely diabetic myocardium, a finding that warrants further mechanistic interrogation. The results support a potential role for therapeutic HNO administration in acute treatment of ischemia and/or heart failure in diabetics.
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Affiliation(s)
- Cheng Xue Qin
- Heart Failure Pharmacology, Baker Heart & Diabetes Institute, Melbourne, Australia.,Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, Australia.,Department of Medicine (Central Clinical School), Monash University, Melbourne, Australia
| | - Jarryd Anthonisz
- Heart Failure Pharmacology, Baker Heart & Diabetes Institute, Melbourne, Australia.,Department of Medicine (Central Clinical School), Monash University, Melbourne, Australia
| | - Chen Huei Leo
- School of Biosciences, University of Melbourne, Parkville, Australia.,Science and Maths Cluster, Singapore University of Technology & Design, Singapore Singapore
| | - Nicola Kahlberg
- School of Biosciences, University of Melbourne, Parkville, Australia
| | - Anida Velagic
- Heart Failure Pharmacology, Baker Heart & Diabetes Institute, Melbourne, Australia.,Department of Medicine (Central Clinical School), Monash University, Melbourne, Australia
| | - Mandy Li
- Heart Failure Pharmacology, Baker Heart & Diabetes Institute, Melbourne, Australia
| | - Edwina Jap
- Heart Failure Pharmacology, Baker Heart & Diabetes Institute, Melbourne, Australia
| | - Owen L Woodman
- Heart Failure Pharmacology, Baker Heart & Diabetes Institute, Melbourne, Australia
| | - Laura J Parry
- School of Biosciences, University of Melbourne, Parkville, Australia
| | - John D Horowitz
- Cardiology Unit, The Queen Elizabeth Hospital, Basil Hetzel Institute, The University of Adelaide, Woodville SA, Australia
| | - Barbara K Kemp-Harper
- Department of Pharmacology, Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Rebecca H Ritchie
- Heart Failure Pharmacology, Baker Heart & Diabetes Institute, Melbourne, Australia.,Department of Pharmacology and Therapeutics, University of Melbourne, Melbourne, Australia.,Department of Medicine (Central Clinical School), Monash University, Melbourne, Australia
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15
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Endothelium-Dependent Hyperpolarization (EDH) in Diabetes: Mechanistic Insights and Therapeutic Implications. Int J Mol Sci 2019; 20:ijms20153737. [PMID: 31370156 PMCID: PMC6695796 DOI: 10.3390/ijms20153737] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 07/25/2019] [Accepted: 07/30/2019] [Indexed: 02/07/2023] Open
Abstract
Diabetes mellitus is one of the major risk factors for cardiovascular disease and is an important health issue worldwide. Long-term diabetes causes endothelial dysfunction, which in turn leads to diabetic vascular complications. Endothelium-derived nitric oxide is a major vasodilator in large-size vessels, and the hyperpolarization of vascular smooth muscle cells mediated by the endothelium plays a central role in agonist-mediated and flow-mediated vasodilation in resistance-size vessels. Although the mechanisms underlying diabetic vascular complications are multifactorial and complex, impairment of endothelium-dependent hyperpolarization (EDH) of vascular smooth muscle cells would contribute at least partly to the initiation and progression of microvascular complications of diabetes. In this review, we present the current knowledge about the pathophysiology and underlying mechanisms of impaired EDH in diabetes in animals and humans. We also discuss potential therapeutic approaches aimed at the prevention and restoration of EDH in diabetes.
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16
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Ali SF, Woodman OL. Tocomin Restores Endothelium-Dependent Relaxation in the Diabetic Rat Aorta by Increasing NO Bioavailability and Improving the Expression of eNOS. Front Physiol 2019; 10:186. [PMID: 30886586 PMCID: PMC6409301 DOI: 10.3389/fphys.2019.00186] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 02/14/2019] [Indexed: 12/15/2022] Open
Abstract
We aimed to determine whether tocomin, an extract from palm oil that has a high tocotrienol content, was able to prevent diabetes-induced endothelial dysfunction. To induce type 1 diabetes streptozotocin (50 mg/kg) was injected into the tail vein of Wistar rats. Six weeks later the diabetic rats, and normal rats injected with citrate buffer, commenced treatment with tocomin (40 mg/kg/day sc) or its vehicle (peanut oil) for a further 4 weeks. Aortae isolated from diabetic rats had impaired acetylcholine (ACh)-induced endothelium-dependent relaxation compared to normal rat aortae but there was no change in endothelium-independent relaxation in response to sodium nitroprusside. By contrast, responses to ACh in aortae from diabetic rats treated with tocomin were not different to normal rats. In addition to impaired endothelium-dependent relaxation the diabetic aortae had increased expression of the NADPH oxidase Nox2 subunit, increased generation of superoxide and decreased expression of eNOS and all of these effects were prevented by tocomin treatment. Tocomin did not affect plasma glucose levels. The impaired response to ACh in vitro was maintained in the presence of TRAM-34 and apamin, selective inhibitors of calcium-activated potassium (K Ca ) channels, indicating diabetes impaired the contribution of NO to endothelium-dependent relaxation. By contrast, neither diabetes nor tocomin treatment influenced EDH-type relaxation as, in the presence of L-NNA, an inhibitor of eNOS, and ODQ, to inhibit soluble guanylate cyclase, responses to ACh were similar in all treatment groups. Thus tocomin treatment improves NO mediated endothelium dependent relaxation in aortae from diabetic rats associated with a decrease in vascular oxidant stress but without affecting hyperglycaemia.
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17
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Histamine and diabetic nephropathy: an up-to-date overview. Clin Sci (Lond) 2019; 133:41-54. [PMID: 30606813 DOI: 10.1042/cs20180839] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/22/2018] [Accepted: 12/10/2018] [Indexed: 01/10/2023]
Abstract
The classification of diabetic nephropathy (DN) as a vascular complication of diabetes makes the possible involvement of histamine, an endogenous amine that is well known for its vasoactive properties, an interesting topic for study. The aim of the present review is to provide an extensive overview of the possible involvement of histamine in the onset and progression of DN. The evidence collected on the role of histamine in kidney function together with its well-known pleiotropic action suggest that this amine may act simultaneously on glomerular hyperfiltration, tubular inflammation, fibrosis development and tubular hypertrophy.
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18
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Abstract
Vascular myography is an in vitro technique used to examine functional responses of isolated blood vessels. This classical pharmacological technique has been in use for over a century. The assay technique studies changes in isometric tone of large and small vessels, arteries and veins, and tissues from genetic or disease models. This chapter describes the apparatus required, tissue collection methods, and the mounting of the tissues in the chambers of both large organ baths and the small vessel myograph. Considerations of the experimental conditions and design are discussed as well as the analysis of the collected data.
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19
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Jelinic M, Leo CH, Marshall SA, Senadheera SN, Parry LJ, Tare M. Short-term (48 hours) intravenous serelaxin infusion has no effect on myogenic tone or vascular remodeling in rat mesenteric arteries. Microcirculation 2018; 24. [PMID: 28370794 DOI: 10.1111/micc.12371] [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: 10/14/2016] [Accepted: 03/24/2017] [Indexed: 01/08/2023]
Abstract
BACKGROUND Short-term IV sRLX (recombinant human relaxin-2) infusion enhances endothelium-dependent relaxation in mesenteric arteries. This is initially underpinned by increased NO followed by a transition to prostacyclin. The effects of short-term IV sRLX treatment on pressure-induced myogenic tone and vascular remodeling in these arteries are unknown. Therefore, we investigated the effects of sRLX infusion on pressure-induced myogenic tone and passive mechanical wall properties in mesenteric arteries. METHODS Mesenteric artery myogenic tone and passive mechanics were examined after 48-hours and 10-days infusion of sRLX. Potential mechanisms of action were assessed by pressure myography, qPCR, and Western blot analysis. RESULTS Neither 48-hours nor 10-days sRLX treatment had significant effects on myogenic tone, passive arterial wall stiffness, volume compliance, or axial lengthening. However, in 48-hours sRLX -treated rats, incubation with the NO synthase blocker L-NAME significantly increased myogenic tone (P<.05 vs placebo), demonstrating an increased contribution of NO to the regulation of myogenic tone. eNOS dimerization, but not phosphorylation, was significantly upregulated in the arteries of sRLX -treated rats. CONCLUSION In mesenteric arteries, 48-hours sRLX treatment upregulates the role of NO in the regulation of myogenic tone by enhancing eNOS dimerization, without altering overall myogenic tone or vascular remodeling.
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Affiliation(s)
- Maria Jelinic
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Chen Huei Leo
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Sarah A Marshall
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | | | - Laura J Parry
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Marianne Tare
- Department of Physiology, Monash University, Clayton, Victoria, Australia.,Monash Rural Health, Monash University, Churchill, Victoria, Australia
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20
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Ng HH, Leo CH, Parry LJ, Ritchie RH. Relaxin as a Therapeutic Target for the Cardiovascular Complications of Diabetes. Front Pharmacol 2018; 9:501. [PMID: 29867503 PMCID: PMC5962677 DOI: 10.3389/fphar.2018.00501] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 04/26/2018] [Indexed: 12/13/2022] Open
Abstract
Cardiovascular complications are the major cause of mortality in patients with diabetes. This is closely associated with both macrovascular and microvascular complications of diabetes, which lead to organ injuries in diabetic patients. Previous studies have consistently demonstrated the beneficial effects of relaxin treatment for protection of the vasculature, with evidence of antioxidant and anti-remodeling actions. Relaxin enhances nitric oxide, prostacyclin and endothelium-derived hyperpolarization (EDH)-type-mediated relaxation in various vascular beds. These effects of relaxin on the systemic vasculature, coupled with its cardiac actions, reduce pulmonary capillary wedge pressure and pulmonary artery pressure. This results in an overall decrease in systemic and pulmonary vascular resistance in heart failure patients. The anti-fibrotic actions of relaxin are well established, a desirable property in the context of diabetes. Further, relaxin ameliorates diabetic wound healing, with accelerated angiogenesis and vasculogenesis. Relaxin-mediated stimulation of vascular endothelial growth factor (VEGF) and stromal cell-derived factor 1-α, as well as regulation of metalloproteinase expression, ameliorates cardiovascular fibrosis in diabetic mice. In the heart, relaxin is a cardioprotective molecule in several experimental animal models, exerting anti-fibrotic, anti-hypertrophy and anti-apoptotic effects in diabetic pathologies. Collectively, these studies provide a foundation to propose the therapeutic potential for relaxin as an adjunctive agent in the prevention or treatment of diabetes-induced cardiovascular complications. This review provides a comprehensive overview of the beneficial effects of relaxin, and identifies its therapeutic possibilities for alleviating diabetes-related cardiovascular injury.
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Affiliation(s)
- Hooi Hooi Ng
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
- Heart Failure Pharmacology, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
- Department of Human and Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, United States
| | - Chen Huei Leo
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
- Science and Math Cluster, Singapore University of Technology and Design, Singapore, Singapore
| | - Laura J. Parry
- School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
| | - Rebecca H. Ritchie
- Heart Failure Pharmacology, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia
- Department of Pharmacology & Therapeutics, The University of Melbourne, Melbourne, VIC, Australia
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21
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3',4'-dihydroxyflavonol ameliorates endoplasmic reticulum stress-induced apoptosis and endothelial dysfunction in mice. Sci Rep 2018; 8:1818. [PMID: 29379034 PMCID: PMC5789000 DOI: 10.1038/s41598-018-19584-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 01/04/2018] [Indexed: 12/25/2022] Open
Abstract
Endoplasmic reticulum (ER) stress has been implicated in the development of hypertension 3 through the induction of endothelial impairment. As 3′,4′-dihydroxyflavonol (DiOHF) 4 reduces vascular injury caused by ischaemia/reperfusion or diabetes, and flavonols have been demonstrated to attenuate ER stress, we investigated whether DiOHF can protect mice from ER stress-induced endothelial dysfunction. Male C57BLK/6 J mice were injected with tunicamycin to induce ER stress in the presence or absence of either DiOHF or tauroursodeoxycholic acid (TUDCA), an inhibitor of ER stress. Tunicamycin elevated blood pressure and impaired endothelium-dependent relaxation. Moreover, in aortae there was evidence of ER stress, oxidative stress and reduced NO production. This was coincident with increased NOX2 expression and reduced phosphorylation of endothelial nitric oxide synthase (eNOS) on Ser1176. Importantly, the effects of tunicamycin were significantly ameliorated by DiOHF or TUDCA. DiOHF also inhibited tunicamycin-induced ER stress and apoptosis in cultured human endothelial cells (HUVEC). These results provide evidence that ER stress is likely an important initiator of endothelial dysfunction through the induction of oxidative stress and a reduction in NO synthesis and that DiOHF directly protects against ER stress- induced injury. DiOHF may be useful to prevent ER and oxidative stress to preserve endothelial function, for example in hypertension.
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22
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Miyazaki T, Miyazaki A. Dysregulation of Calpain Proteolytic Systems Underlies Degenerative Vascular Disorders. J Atheroscler Thromb 2017; 25:1-15. [PMID: 28819082 PMCID: PMC5770219 DOI: 10.5551/jat.rv17008] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Chronic vascular diseases such as atherosclerosis, aneurysms, diabetic angiopathy/retinopathy as well as fibrotic and proliferative vascular diseases are generally complicated by the progression of degenerative insults, which are characterized by endothelial dysfunction, apoptotic/necrotic cell death in vascular/immune cells, remodeling of extracellular matrix or breakdown of elastic lamella. Increasing evidence suggests that dysfunctional calpain proteolytic systems and defective calpain protein metabolism in blood vessels contribute to degenerative disorders. In vascular endothelial cells, the overactivation of conventional calpains consisting of calpain-1 and -2 isozymes can lead to the disorganization of cell-cell junctions, dysfunction of nitric oxide synthase, sensitization of Janus kinase/signal transducer and activator of transcription cascades and depletion of prostaglandin I2, which contributes to degenerative disorders. In addition to endothelial cell dysfunctions, calpain overactivation results in inflammatory insults in macrophages and excessive fibrogenic/proliferative signaling in vascular smooth muscle cells. Moreover, calpain-6, a non-proteolytic unconventional calpain, is involved in the conversion of macrophages to a pro-atherogenic phenotype, leading to the pinocytotic deposition of low-density lipoprotein cholesterol in the cells. Here, we discuss the recent progress that has been made in our understanding of how calpain contributes to degenerative vascular disorders.
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Affiliation(s)
- Takuro Miyazaki
- Department of Biochemistry, Showa University School of Medicine
| | - Akira Miyazaki
- Department of Biochemistry, Showa University School of Medicine
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23
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Ng HH, Yildiz GS, Ku JM, Miller AA, Woodman OL, Hart JL. Chronic NaHS treatment decreases oxidative stress and improves endothelial function in diabetic mice. Diab Vasc Dis Res 2017; 14:246-253. [PMID: 28467198 DOI: 10.1177/1479164117692766] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Hydrogen sulphide (H2S) is endogenously produced in vascular tissue and has anti-oxidant and vasoprotective properties. This study investigates whether chronic treatment using the fast H2S donor NaHS could elicit a vasoprotective effect in diabetes. Diabetes was induced in male C57BL6/J mice with streptozotocin (60 mg/kg daily, ip for 2 weeks) and confirmed by elevated blood glucose and glycated haemoglobin levels. Diabetic mice were then treated with NaHS (100 µmol/kg/day) for 4 weeks, and aortae collected for functional and biochemical analyses. In the diabetic group, both endothelium-dependent vasorelaxation and basal nitric oxide (NO•) bioactivity were significantly reduced ( p < 0.05), and maximal vasorelaxation to the NO• donor sodium nitroprusside was impaired ( p < 0.05) in aorta compared to control mice. Vascular superoxide generation via nicotine adenine dinucleotide phosphate (NADPH) oxidase ( p < 0.05) was elevated in aorta from diabetic mice which was associated with increased expression of NOX2 ( p < 0.05). NaHS treatment of diabetic mice restored endothelial function and exogenous NO• efficacy back to control levels. NaHS treatment also reduced the diabetes-induced increase in NADPH oxidase activity, but did not affect NOX2 protein expression. These data show that chronic NaHS treatment reverses diabetes-induced vascular dysfunction by restoring NO• efficacy and reducing superoxide production in the mouse aorta.
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MESH Headings
- Animals
- Antioxidants/administration & dosage
- Blood Glucose/metabolism
- Diabetes Mellitus, Experimental/blood
- Diabetes Mellitus, Experimental/complications
- Diabetes Mellitus, Experimental/drug therapy
- Diabetic Angiopathies/etiology
- Diabetic Angiopathies/metabolism
- Diabetic Angiopathies/physiopathology
- Diabetic Angiopathies/prevention & control
- Dose-Response Relationship, Drug
- Drug Administration Schedule
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiopathology
- Glycated Hemoglobin/metabolism
- Male
- Mice, Inbred C57BL
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiopathology
- NADPH Oxidase 2/metabolism
- Nitric Oxide/metabolism
- Nitric Oxide Donors/pharmacology
- Nitric Oxide Synthase Type III/metabolism
- Oxidative Stress/drug effects
- Sulfides/administration & dosage
- Superoxides/metabolism
- Time Factors
- Vasodilation/drug effects
- Vasodilator Agents/pharmacology
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Affiliation(s)
- Hooi H Ng
- 1 School of BioSciences, University of Melbourne, Parkville, VIC, Australia
| | - Gunes S Yildiz
- 2 School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
| | - Jacqueline M Ku
- 2 School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
| | - Alyson A Miller
- 2 School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
| | - Owen L Woodman
- 2 School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
| | - Joanne L Hart
- 2 School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
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Leo CH, Fernando DT, Tran L, Ng HH, Marshall SA, Parry LJ. Serelaxin Treatment Reduces Oxidative Stress and Increases Aldehyde Dehydrogenase-2 to Attenuate Nitrate Tolerance. Front Pharmacol 2017; 8:141. [PMID: 28377719 PMCID: PMC5359255 DOI: 10.3389/fphar.2017.00141] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 03/07/2017] [Indexed: 02/01/2023] Open
Abstract
Background: Glyceryl trinitrate (GTN) is a commonly prescribed treatment for acute heart failure patients. However, prolonged GTN treatment induces tolerance, largely due to increased oxidative stress and reduced aldehyde dehydrogenase-2 (ALDH-2) expression. Serelaxin has several vasoprotective properties, which include reducing oxidative stress and augmenting endothelial function. We therefore tested the hypothesis in rodents that serelaxin treatment could attenuate low-dose GTN-induced tolerance. Methods and Results: Co-incubation of mouse aortic rings ex vivo with GTN (10 μM) and serelaxin (10 nM) for 1 h, restored GTN responses, suggesting that serelaxin prevented the development of GTN tolerance. Male Wistar rats were subcutaneously infused with ethanol (control), low-dose GTN+placebo or low-dose GTN+serelaxin via osmotic minipumps for 3 days. Aortic vascular function and superoxide levels were assessed using wire myography and lucigenin-enhanced chemiluminescence assay respectively. Changes in aortic ALDH-2 expression were measured by qPCR and Western blot respectively. GTN+placebo infusion significantly increased superoxide levels, decreased ALDH-2 and attenuated GTN-mediated vascular relaxation. Serelaxin co-treatment with GTN significantly enhanced GTN-mediated vascular relaxation, reduced superoxide levels and increased ALDH-2 expression compared to GTN+placebo-treated rats. Conclusion: Our data demonstrate that a combination of serelaxin treatment with low dose GTN attenuates the development of GTN-induced tolerance by reducing superoxide production and increasing ALDH-2 expression in the rat aorta. We suggest that serelaxin may improve nitrate efficacy in a clinical setting.
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Affiliation(s)
- Chen Huei Leo
- School of BioSciences, The University of Melbourne, Parkville VIC, Australia
| | | | - Lillie Tran
- School of BioSciences, The University of Melbourne, Parkville VIC, Australia
| | - Hooi Hooi Ng
- School of BioSciences, The University of Melbourne, Parkville VIC, Australia
| | - Sarah A Marshall
- School of BioSciences, The University of Melbourne, Parkville VIC, Australia
| | - Laura J Parry
- School of BioSciences, The University of Melbourne, Parkville VIC, Australia
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25
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Ng HH, Leo CH, O'Sullivan K, Alexander SA, Davies MJ, Schiesser CH, Parry LJ. 1,4-Anhydro-4-seleno-d-talitol (SeTal) protects endothelial function in the mouse aorta by scavenging superoxide radicals under conditions of acute oxidative stress. Biochem Pharmacol 2016; 128:34-45. [PMID: 28027880 DOI: 10.1016/j.bcp.2016.12.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2016] [Accepted: 12/23/2016] [Indexed: 02/07/2023]
Abstract
Hyperglycaemia increases the generation of reactive oxidants in blood vessels and is a major cause of endothelial dysfunction. A water-soluble selenium-containing sugar (1,4-Anhydro-4-seleno-d-talitol, SeTal) has potent antioxidant activity in vitro and is a promising treatment to accelerate wound healing in diabetic mice. One possible mechanism of SeTal action is a direct effect on blood vessels. Therefore, we tested the hypothesis that SeTal prevents endothelial dysfunction by scavenging reactive oxidants in isolated mouse aorta under conditions of acute oxidative stress induced by hyperglycaemia. Aortae were isolated from C57BL/6 male mice and mounted on a wire-myograph to assess vascular function. In the presence of a superoxide radical generator, pyrogallol, 300μM and 1mM of SeTal effectively prevented endothelial dysfunction compared to other selenium-containing compounds. In a second set of ex vivo experiments, mouse aortae were incubated for three days with either normal or high glucose, and co-incubated with SeTal at 37°C in 5% CO2. High glucose significantly reduced the sensitivity to the endothelium-dependent agonist, acetylcholine (ACh), increased superoxide production and decreased basal nitric oxide (NO) availability. SeTal (1mM) co-treatment prevented high glucose-induced endothelial dysfunction and oxidative stress in the mouse aorta. The presence of a cyclooxygenase inhibitor, indomethacin significantly improved the sensitivity to ACh in high glucose-treated aortae, but had no effect in SeTal-treated aortae. Our data show that SeTal has potent antioxidant activity in isolated mouse aortae and prevents high glucose-induced endothelial dysfunction by decreasing superoxide levels, increasing basal NO availability and normalising the contribution of vasoconstrictor prostanoids.
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Affiliation(s)
- Hooi Hooi Ng
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia.
| | - Chen Huei Leo
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia.
| | - Kelly O'Sullivan
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia.
| | - Stefanie-Ann Alexander
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC 3010, Australia.
| | - Michael J Davies
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen, Denmark.
| | - Carl H Schiesser
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, VIC 3010, Australia.
| | - Laura J Parry
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010, Australia.
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26
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Ali SF, Nguyen JCD, Jenkins TA, Woodman OL. Tocotrienol-Rich Tocomin Attenuates Oxidative Stress and Improves Endothelium-Dependent Relaxation in Aortae from Rats Fed a High-Fat Western Diet. Front Cardiovasc Med 2016; 3:39. [PMID: 27800483 PMCID: PMC5065990 DOI: 10.3389/fcvm.2016.00039] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 09/30/2016] [Indexed: 01/23/2023] Open
Abstract
We have previously reported that tocomin, a mixture high in tocotrienol content and also containing tocopherol, acutely preserves endothelial function in the presence of oxidative stress. In this study, we investigated whether tocomin treatment would preserve endothelial function in aortae isolated from rats fed a high-fat diet known to cause oxidative stress. Wistar hooded rats were fed a western diet (WD, 21% fat) or control rat chow (standard diet, 6% fat) for 12 weeks. Tocomin (40 mg/kg/day sc) or its vehicle (peanut oil) was administered for the last 4 weeks of the feeding regime. Aortae from WD rats showed an impairment of endothelium-dependent relaxation that was associated with an increased expression of the NADPH oxidase Nox2 subunit and an increase in the vascular generation of superoxide measured using L-012 chemiluminescence. The increase in vascular oxidative stress was accompanied by a decrease in basal NO release and impairment of the contribution of NO to ACh-induced relaxation. The impaired relaxation is likely contributed to by a decreased expression of eNOS, calmodulin, and phosphorylated Akt and an increase in caveolin. Tocotrienol rich tocomin, which prevented the diet-induced changes in vascular function, reduced vascular superoxide production and abolished the diet-induced changes in eNOS and other protein expression. Using selective inhibitors of nitric oxide synthase (NOS), soluble guanylate cyclase (sGC) and calcium-activated potassium (KCa) channels we demonstrated that tocomin increased NO-mediated relaxation, without affecting the contribution of endothelium-dependent hyperpolarization type relaxation to the endothelium-dependent relaxation. The beneficial actions of tocomin in this diet-induced model of obesity suggest that it may have potential to be used as a therapeutic agent to prevent vascular disease in obesity.
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Affiliation(s)
- Saher F Ali
- School of Health and Biomedical Sciences, RMIT University , Bundoora, VIC , Australia
| | - Jason C D Nguyen
- School of Health and Biomedical Sciences, RMIT University , Bundoora, VIC , Australia
| | - Trisha A Jenkins
- School of Health and Biomedical Sciences, RMIT University , Bundoora, VIC , Australia
| | - Owen L Woodman
- School of Health and Biomedical Sciences, RMIT University , Bundoora, VIC , Australia
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Kahlberg N, Qin CX, Anthonisz J, Jap E, Ng HH, Jelinic M, Parry LJ, Kemp-Harper BK, Ritchie RH, Leo CH. Adverse vascular remodelling is more sensitive than endothelial dysfunction to hyperglycaemia in diabetic rat mesenteric arteries. Pharmacol Res 2016; 111:325-335. [DOI: 10.1016/j.phrs.2016.06.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 06/15/2016] [Accepted: 06/26/2016] [Indexed: 11/26/2022]
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Abstract
As flavonols are present in fruits and vegetables, they are consumed in considerable amounts in the diet. There is growing evidence that the well-recognized antioxidant, anti-inflammatory, and vasorelaxant actions of flavonols may, at least in part, result from modulation of biochemical signaling pathways and kinases. It is well established that diabetes is associated with increased cardiovascular morbidity and mortality. Despite clinical management of blood glucose levels, diabetes often results in cardiovascular disease. There is good evidence that endothelial dysfunction contributes significantly to the progression of diabetic cardiovascular diseases. This review describes the biological actions of flavonols that may ameliorate adverse cardiovascular events in diabetes. We discuss evidence that flavonols may be developed as novel pharmacological agents to prevent diabetes-induced vascular dysfunction.
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Oz M, Demir EA, Caliskan M, Mogulkoc R, Baltaci AK, Nurullahoglu Atalik KE. 3′,4′-Dihydroxyflavonol attenuates spatial learning and memory impairments in global cerebral ischemia. Nutr Neurosci 2016; 20:119-126. [DOI: 10.1179/1476830514y.0000000159] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Affiliation(s)
- Mehmet Oz
- Department of Physiology, Faculty of Medicine, University of Selcuk, Konya, Turkey
| | - Enver Ahmet Demir
- Department of Physiology, Faculty of Medicine, University of Selcuk, Konya, Turkey
| | - Merve Caliskan
- Department of Physiology, Faculty of Medicine, University of Selcuk, Konya, Turkey
| | - Rasim Mogulkoc
- Department of Physiology, Faculty of Medicine, University of Selcuk, Konya, Turkey
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Leo CH, Jelinic M, Ng HH, Tare M, Parry LJ. Time-dependent activation of prostacyclin and nitric oxide pathways during continuous i.v. infusion of serelaxin (recombinant human H2 relaxin). Br J Pharmacol 2016; 173:1005-17. [PMID: 26660642 DOI: 10.1111/bph.13404] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 12/02/2015] [Accepted: 12/04/2015] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AND PURPOSE In the RELAX-AHF trial, a 48 h i.v. serelaxin infusion reduced systemic vascular resistance in patients with acute heart failure. Consistent with preclinical studies, serelaxin augments endothelial vasodilator function in rat mesenteric arteries. Little is known about the contribution of endothelium-derived relaxing factors after a longer duration of continuous serelaxin treatment. Here we have assessed vascular reactivity and mechanistic pathways in mesenteric arteries and veins and the aorta after 48 or 72 h continuous i.v. infusion of serelaxin. EXPERIMENTAL APPROACH Male rats were infused with either placebo or serelaxin (13.3 μg·kg(-1) ·h(-1) ) via the jugular vein using osmotic minipumps. Vascular function was assessed using wire myography. Changes in gene and protein expression and 6-keto PGF1α levels were determined by quantitative PCR, Western blot and ELISA respectively. KEY RESULTS Continuous i.v. serelaxin infusion augmented endothelium-dependent relaxation in arteries (mesenteric and aorta) but not in mesenteric veins. In mesenteric arteries, 48 h i.v. serelaxin infusion increased basal NOS activity, associated with increased endothelial NOS (eNOS) expression. Interestingly, phosphorylated-eNOS(Ser1177) , eNOS and basal NOS activity were reduced in mesenteric arteries following 72 h serelaxin treatment. At 72 h, serelaxin treatment improved bradykinin-mediated relaxation through COX2-derived PGI2 production. CONCLUSIONS AND IMPLICATIONS Continuous i.v. serelaxin infusion enhanced endothelial vasodilator function in arteries but not in veins. The underlying mediator at 48 h was NO but there was a transition to PGI2 by 72 h. Activation of the PGI2 -dependent pathway is key to the prolonged vascular response to serelaxin treatment.
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Affiliation(s)
- C H Leo
- School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
| | - M Jelinic
- School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
| | - H H Ng
- School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
| | - M Tare
- Department of Physiology and School of Rural Health, Monash University, Parkville, Vic, Australia
| | - L J Parry
- School of BioSciences, The University of Melbourne, Parkville, Vic, Australia
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Ng HH, Jelinic M, Parry LJ, Leo CH. Increased superoxide production and altered nitric oxide-mediated relaxation in the aorta of young but not old male relaxin-deficient mice. Am J Physiol Heart Circ Physiol 2015; 309:H285-96. [DOI: 10.1152/ajpheart.00786.2014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 05/06/2015] [Indexed: 11/22/2022]
Abstract
The vascular effects of exogenous relaxin (Rln) treatment are well established and include decreased myogenic reactivity and enhanced relaxation responses to vasodilators in small resistance arteries. These vascular responses are reduced in older animals, suggesting that Rln is less effective in mediating arterial function with aging. The present study investigated the role of endogenous Rln in the aorta and the possibility that vascular dysfunction occurs more rapidly with aging in Rln-deficient ( Rln−/−) mice. We compared vascular function and underlying vasodilatory pathways in the aorta of male wild-type ( Rln+/+) and Rln−/− mice at 4 and 16 mo of age using wire myography. Superoxide production, but not nitrotyrosine or NADPH oxidase expression, was significantly increased in the aorta of young Rln−/− mice, whereas endothelial nitric oxide (NO) synthase and basal NO availability were both significantly decreased compared with Rln+/+ mice. In the presence of the cyclooxygenase inhibitor indomethacin, sensitivity to ACh was significantly decreased in young Rln−/− mice, demonstrating altered NO-mediated relaxation that was normalized in the presence of a membrane-permeable SOD or ROS scavenger. These vascular phenotypes were not exacerbated in old Rln−/− mice and, in most cases, did not differ significantly from old Rln+/+ mice. Despite the vascular phenotypes in Rln−/− mice, endothelium-dependent and -independent vasodilation were not adversely affected. Our data show a role for endogenous Rln in reducing superoxide production and maintaining NO availability in the aorta but also demonstrate that Rln deficiency does not compromise vascular function in this artery or exacerbate endothelial dysfunction associated with aging.
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Affiliation(s)
- Hooi H. Ng
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Maria Jelinic
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Laura J. Parry
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
| | - Chen-Huei Leo
- School of BioSciences, The University of Melbourne, Parkville, Victoria, Australia
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Hydrogen sulfide treatment reduces blood pressure and oxidative stress in angiotensin II-induced hypertensive mice. Hypertens Res 2014; 38:13-20. [PMID: 25099489 DOI: 10.1038/hr.2014.125] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 06/16/2014] [Accepted: 07/09/2014] [Indexed: 12/21/2022]
Abstract
Hydrogen sulfide (H2S) is increasingly recognized as a gasotransmitter with protective effects in the cardiovascular system. The aim of the study was to examine the effects of chronic NaHS treatment on blood pressure, vascular function and oxidative stress in an in vivo model of hypertension and oxidative stress. Male C57Bl6/J mice were rendered hypertensive with 0.7 mg kg(-1) per day angiotensin II (AngII) for 14 days administered via implanted mini-pumps. The mice were treated with NaHS (10 μmol kg(-1) per day) to deliver H2S or an inhibitor of cystathionine-γ-lyase, DL-propargylglycine (PPG 30 mg kg(-1) per day) via intraperitoneal (i.p.) injection. Systolic blood pressure was measured and vascular function examined by myography. Vascular superoxide production was measured by lucigenin-enhanced chemiluminescence. AngII infusion significantly increased systolic blood pressure (P < 0.001). This increase was significantly attenuated by treatment with NaHS (P < 0.001). Both aortic endothelial function and NO bioavailability were significantly attenuated in the AngII group (P < 0.01) but this attenuation was reversed by NaHS treatment. Similarly, aortic superoxide anion production was significantly enhanced by AngII (P < 0.01), and this was reversed by NaHS treatment, and also exacerbated by PPG treatment (P < 0.001). These data show that in a mouse model of hypertension and oxidative stress induced by AngII, exogenous H2S treatment in vivo reduces blood pressure, endothelial dysfunction and vascular oxidative stress, while inhibiting endogenous H2S production in vivo is deleterious. This furthers the evidence that H2S is a vasoprotective molecule that may be a useful treatment target in cardiovascular disease.
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Inhibition of calpain reduces oxidative stress and attenuates endothelial dysfunction in diabetes. Cardiovasc Diabetol 2014; 13:88. [PMID: 24886224 PMCID: PMC4045988 DOI: 10.1186/1475-2840-13-88] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 04/25/2014] [Indexed: 12/25/2022] Open
Abstract
Aims The present study was to investigate the role of calpain in reactive oxygen species (ROS) production in endothelial cells and endothelium-dependent vascular dysfunction under experimental conditions of diabetes. Methods and results Exposure to high glucose activated calpain, induced apoptosis and reduced nitric oxide (NO) production without changing eNOS protein expression, its phosphorylation and dimers formation in primary human umbilical vein endothelial cells (HUVECs). These effects of high glucose correlated with intracellular ROS production and mitochondrial superoxide generation. Selectively scavenging mitochondrial superoxide increased NO production in high glucose-stimulated HUVECs. Inhibition of calpain using over-expression of calpastatin or pharmacological calpain inhibitor prevented high glucose-induced ROS production, mitochondrial superoxide generation and apoptosis, which were concurrent with an elevation of NO production in HUVECs. In mouse models of streptozotocin-induced type-1 diabetes and OVE26 type-1 diabetic mice, calpain activation correlated with an increase in ROS production and peroxynitrite formation in aortas. Transgenic over-expression of calpastatin reduced ROS production and peroxynitrite formation in diabetic mice. In parallel, diabetes-induced reduction of endothelium-dependent relaxation in aortic ring was reversed by over-expression of calpastatin in mouse models of diabetes. However, the protective effect of calpastatin on endothelium-dependent relaxation was abrogated by eNOS deletion in diabetic mice. Conclusions This study suggests that calpain may play a role in vascular endothelial cell ROS production and endothelium-dependent dysfunction in diabetes. Thus, calpain may be an important therapeutic target to overcome diabetes-induced vascular dysfunction.
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Mosawy S, Jackson DE, Woodman OL, Linden MD. The flavonols quercetin and 3',4'-dihydroxyflavonol reduce platelet function and delay thrombus formation in a model of type 1 diabetes. Diab Vasc Dis Res 2014; 11:174-81. [PMID: 24623318 DOI: 10.1177/1479164114524234] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Diabetes is associated with increased cardiovascular risk. We have recently shown that the naturally occurring flavonol quercetin (Que) or the synthetic flavonol 3',4'-dihydroxyflavonol (DiOHF) inhibits platelet function and delays thrombus formation in healthy mice. Therefore, the aim of this study was to investigate the effect of Que or DiOHF treatment on platelet function and ferric chloride-induced carotid artery thrombosis in a mouse model of type 1 diabetes. Diabetic mice treated with Que or DiOHF maintained blood flow at a significantly higher level than untreated diabetic mice at the end of the recording period. In addition, treatment with Que or DiOHF significantly reduced diabetes-induced platelet hyper-aggregability in response to platelet agonist stimulation. Furthermore, treatment with Que or DiOHF significantly inhibited dense, but not alpha, granule exocytosis in diabetic and control mice. Our demonstration that flavonols delay thrombus formation in diabetes suggests a potential clinical role for these compounds in anti-platelet therapy.
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Affiliation(s)
- Sapha Mosawy
- School of Medical Sciences, RMIT University, Melbourne, VIC, Australia
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Leo CH, Jelinic M, Parkington HC, Tare M, Parry LJ. Acute intravenous injection of serelaxin (recombinant human relaxin-2) causes rapid and sustained bradykinin-mediated vasorelaxation. J Am Heart Assoc 2014; 3:e000493. [PMID: 24584737 PMCID: PMC3959707 DOI: 10.1161/jaha.113.000493] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Background A recent clinical trial (RELAXin in Acute Heart Failure [RELAX‐AHF]) demonstrated that 48 hours of continuous intravenous infusion of the vasorelaxant peptide serelaxin (recombinant human relaxin‐2) to patients with acute heart failure reduced cardiovascular mortality at 180 days. The persistence of a vasorelaxant response as a potential mechanism for this long‐term benefit and the vascular effects of a bolus intravenous injection of serelaxin have not been examined. This study investigates changes in resistance artery reactivity and passive mechanical wall properties following an intravenous serelaxin injection and whether these vascular effects persist in the absence of detectable circulating serelaxin. Methods and Results Male rats were injected with 13.3 μg/kg serelaxin into the tail vein; mesenteric arteries were assessed 3 and 24 hours after treatment by using wire‐myography. Serelaxin increased basal nitric oxide synthase activity and reduced maximal contraction to endothelin‐1 at 3 hours after administration. Serelaxin treatment also selectively enhanced bradykinin‐mediated endothelium‐dependent relaxation. This effect was sustained for 24 hours in the absence of circulating serelaxin. Serelaxin‐mediated augmentation of bradykinin‐evoked relaxation involved endothelium‐derived hyperpolarization after 3 hours and prostacyclin‐mediated relaxation after 24 hours. Furthermore, upregulation of inducible nitric oxide synthase, phosphorylation of protein kinase B at Ser473 and endothelial nitric oxide synthase at Ser1177 was observed at 24 hours after serelaxin injection. There were no effects of serelaxin on passive arterial wall stiffness. Conclusion Our data show that a bolus intravenous injection of serelaxin modulates endothelial vasodilator function 3 hours after administration, an effect that was sustained for 24 hours. The prolonged bradykinin‐mediated vasorelaxation is principally mediated through prostacyclin.
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Affiliation(s)
- Chen Huei Leo
- Department of Zoology, The University of Melbourne, Parkville, VIC, Australia
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Mosawy S, Jackson DE, Woodman OL, Linden MD. Treatment with quercetin and 3',4'-dihydroxyflavonol inhibits platelet function and reduces thrombus formation in vivo. J Thromb Thrombolysis 2014; 36:50-7. [PMID: 23070586 DOI: 10.1007/s11239-012-0827-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Flavonols are polyphenolic compounds with reported cardiovascular benefits and have been shown to exhibit antiplatelet properties in vitro. While some studies have shown inhibition of platelet aggregation following dietary supplementation with flavonol rich foods, few studies have assessed the ability of flavonols to inhibit platelet mediated thrombus generation in vivo. Furthermore, the duration of benefit and the influence of different dosing regimens remain unclear. In this study we investigate the ability of two structurally related flavonols; quercetin (Que) and 3',4'-dihydroxyflavonol (DiOHF) to inhibit platelet aggregation, platelet granule exocytosis and vessel occlusion in a well characterized mouse model of platelet mediated arterial thrombosis. We investigated the effect of a single 6 mg/kg intravenous bolus and daily 6 mg/kg intraperitoneal doses over seven consecutive days. Carotid artery blood flow after injury was better maintained in mice treated with both Que and DiOHF when compared to the vehicle for both dosage regimens. This improved blood flow corresponded to inhibition of platelet aggregation and platelet dense granule exocytosis following chemical stimulation of PAR4. We therefore provide evidence of inhibition of platelet-mediated arterial thrombosis by flavonols in vivo, and demonstrate that this effect persists for at least 24 h after the last intraperitoneal dose. These data suggest a potential clinical role for flavonols as anti-platelet therapy.
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Affiliation(s)
- S Mosawy
- School of Medical Sciences, RMIT University, Melbourne, VIC, Australia
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Streeter EY, Badoer E, Woodman OL, Hart JL. Effect of type 1 diabetes on the production and vasoactivity of hydrogen sulfide in rat middle cerebral arteries. Physiol Rep 2013; 1:e00111. [PMID: 24303182 PMCID: PMC3841046 DOI: 10.1002/phy2.111] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 09/07/2013] [Accepted: 09/09/2013] [Indexed: 01/03/2023] Open
Abstract
Hydrogen sulfide (H2S) is produced endogenously in vascular tissue and has both vasoregulation and antioxidant effects. This study examines the effect of diabetes-induced oxidative stress on H2S production and function in rat middle cerebral arteries. Diabetes was induced in rats with streptozotocin (50 mg/kg, i.v.). Middle cerebral artery function was examined using a small vessel myograph and superoxide anion generation measured using nicotinamide adenine dinucleotide phosphate (NADPH)-dependent lucigenin-enhanced chemiluminescence. Cystathionine-γ-lyase (CSE) mRNA expression was measured via RT-PCR. Diabetic rats had elevated blood glucose and significantly reduced cerebral artery endothelial function. Maximum vasorelaxation to the H2S donor NaHS was unaffected in diabetic cerebral arteries and was elicited via a combination of K+, Cl−, and Ca2+ channel modulation, although the contribution of Cl− channels was significantly less in the diabetic cerebral arteries. Vasorelaxation to the H2S precursor l-cysteine and CSE mRNA were significantly increased in diabetic cerebral arteries. Cerebral artery superoxide production was significantly increased in diabetes, but this increase was attenuated ex vivo by incubation with the H2S donor NaHS. These data confirm that cerebral artery endothelial dysfunction and oxidative stress occurs in diabetes. Endogenous H2S production and activity is upregulated in cerebral arteries in this model of diabetes. Vasorelaxation responses to exogenous H2S are preserved and exogenous H2S attenuates the enhanced cerebral artery generated superoxide observed in the diabetic group. These data suggest that upregulation of endogenous H2S in diabetes may play an antioxidant and vasoprotective role.
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Affiliation(s)
- Elosie Y Streeter
- School of Medical Sciences and Health Innovations Research Institute, RMIT University Bundoora, Victoria, 3083, Australia
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COX-2-derived prostanoids and oxidative stress additionally reduce endothelium-mediated relaxation in old type 2 diabetic rats. PLoS One 2013; 8:e68217. [PMID: 23874545 PMCID: PMC3706542 DOI: 10.1371/journal.pone.0068217] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 05/29/2013] [Indexed: 01/05/2023] Open
Abstract
Endothelial dysfunction in resistance arteries alters end organ perfusion in type 2 diabetes. Superoxides and cyclooxygenase-2 (COX-2) derivatives have been shown separately to alter endothelium-mediated relaxation in aging and diabetes but their role in the alteration of vascular tone in old diabetic subjects is not clear, especially in resistance arteries. Consequently, we investigated the role of superoxide and COX-2-derivatives on endothelium-dependent relaxation in 3 and 12 month-old Zucker diabetic fatty (ZDF) and lean (LZ) rats. Mesenteric resistance arteries were isolated and vascular tone was investigated using wire-myography. Endothelium (acetylcholine)-dependent relaxation was lower in ZDF than in LZ rats (60 versus 84% maximal relaxation in young rats and 41 versus 69% in old rats). Blocking NO production with L-NAME was less efficient in old than in young rats. L-NAME had no effect in old ZDF rats although eNOS expression level in old ZDF rats was similar to that in old LZ rats. Superoxide level and NADPH-oxidase subunits (p67phox and gp91phox) expression level were greater in ZDF than in LZ rats and were further increased by aging in ZDF rats. In young ZDF rats reducing superoxide level with tempol restored acetylcholine-dependent relaxation to the level of LZ rats. In old ZDF rats tempol improved acetylcholine-dependent relaxation without increasing it to the level of LZ rats. COX-2 (immunolabelling and Western-blot) was present in arteries of ZDF rats and absent in LZ rats. In old ZDF rats arterial COX-2 level was higher than in young ZDF rats. COX-2 blockade with NS398 restored in part acetylcholine-dependent relaxation in arteries of old ZDF rats and the combination of tempol and NS398 fully restored relaxation in control (LZ rats) level. Accordingly, superoxide production and COX-2 derivatives together reduced endothelium-dependent relaxation in old ZDF rats whereas superoxides alone attenuated relaxation in young ZDF or old LZ rats.
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Chronic NaHS Treatment Is Vasoprotective in High-Fat-Fed ApoE(-/-) Mice. Int J Vasc Med 2013; 2013:915983. [PMID: 23864951 PMCID: PMC3707268 DOI: 10.1155/2013/915983] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 06/12/2013] [Indexed: 01/23/2023] Open
Abstract
Hydrogen sulfide is emerging as an important mediator of vascular function that has antioxidant and cytoprotective effects. The aim of this study was to investigate the role of endogenous H2S and the effect of chronic exogenous H2S treatment on vascular function during the progression of atherosclerotic disease. ApoE−/− mice were fed a high-fat diet for 16 weeks and treated with the H2S donor NaHS or the cystathionine-γ-lyase (CSE) inhibitor D,L-propargylglycine (PPG), to inhibit endogenous H2S production for the final 4 weeks. Fat-fed ApoE−/− mice displayed significant aortic atherosclerotic lesions and significantly impaired endothelial function compared to wild-type mice. Importantly, 4 weeks of NaHS treatment significantly reduced vascular dysfunction and inhibited vascular superoxide generation. NaHS treatment significantly reduced the area of aortic atherosclerotic lesions and attenuated systolic blood pressure. Interestingly, inhibiting endogenous, CSE-dependent H2S production with PPG did not exacerbate the deleterious vascular changes seen in the untreated fat-fed ApoE−/− mice. The results indicate NaHS can improve vascular function by reducing vascular superoxide generation and impairing atherosclerotic lesion development. Endogenous H2S production via CSE is insufficient to counter the atherogenic effects seen in this model; however exogenous H2S treatment has a significant vasoprotective effect.
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Martínez-Revelles S, Avendaño MS, García-Redondo AB, Alvarez Y, Aguado A, Pérez-Girón JV, García-Redondo L, Esteban V, Redondo JM, Alonso MJ, Briones AM, Salaices M. Reciprocal relationship between reactive oxygen species and cyclooxygenase-2 and vascular dysfunction in hypertension. Antioxid Redox Signal 2013; 18:51-65. [PMID: 22671943 DOI: 10.1089/ars.2011.4335] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AIMS This study evaluates a possible relationship between reactive oxygen species (ROS) and cyclooxygenase (COX)-2-derived products in conductance and resistance arteries from hypertensive animals. Angiotensin II (Ang II)-infused mice or spontaneously hypertensive rats treated with the NAD(P)H Oxidase inhibitor apocynin, the mitochondrion-targeted SOD2 mimetic Mito-TEMPO, the superoxide dismutase analog tempol, or the COX-2 inhibitor Celecoxib were used. RESULTS Apocynin, Mito-TEMPO, and Celecoxib treatments prevented Ang II-induced hypertension, the increased vasoconstrictor responses to phenylephrine, and the reduced acetylcholine relaxation. The NOX-2 inhibitor gp91ds-tat, the NOX-1 inhibitor ML171, catalase, and the COX-2 inhibitor NS398 abolished the ex vivo effect of Ang II-enhancing phenylephrine responses. Antioxidant treatments diminished the increased vascular COX-2 expression, prostanoid production, and/or participation of COX-derived contractile prostanoids and thromboxane A(2) receptor (TP) in phenylephrine responses, observed in arteries from hypertensive models. The treatment with the COX-2 inhibitor normalized the increased ROS production (O(2)·(-) and H(2)O(2)), NAD(P)H Oxidase expression (NOX-1, NOX-4, and p22phox) and activity, MnSOD expression, and the participation of ROS in vascular responses in both hypertensive models. Apocynin and Mito-TEMPO also normalized these parameters of oxidative stress. Apocynin, Mito-TEMPO, and Celecoxib improved the diminished nitric oxide (NO) production and the modulation by NO of phenylephrine responses in the Ang II model. INNOVATION This study provides mechanistic evidence of circuitous relationship between COX-2 products and ROS in hypertension. CONCLUSION The excess of ROS from NAD(P)H Oxidase and/or mitochondria and the increased vascular COX-2/TP receptor axis act in concert to induce vascular dysfunction and hypertension.
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Affiliation(s)
- Sonia Martínez-Revelles
- Department of Pharmacology, School of Medicine, Universidad Autónoma de Madrid, Institute for Health Research of La Paz University Hospital (IdiPAZ), Madrid, Spain
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Mosawy S, Jackson DE, Woodman OL, Linden MD. Inhibition of platelet-mediated arterial thrombosis and platelet granule exocytosis by 3',4'-dihydroxyflavonol and quercetin. Platelets 2012; 24:594-604. [PMID: 23249183 DOI: 10.3109/09537104.2012.749396] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Flavonols are polyphenolic compounds with broad-spectrum kinase inhibitory, as well as potent anti-oxidant and anti-inflammatory properties. Anti-platelet potential of quercetin (Que) and several related flavonoids have been reported; however, few studies have assessed the ability of flavonols to inhibit exocytosis of different platelet granules or to inhibit thrombus formation in vivo. 3',4'-Dihydroxyflavonol (DiOHF) is a flavonol which is structurally related to Que and has been shown to have greater anti-oxidant capacity and to improve the endothelial function in the context of diabetes and ischaemia/reperfusion injury. While the structural similarity to Que suggests DiOHF may have a potential to inhibit platelet function, no studies have assessed the anti-platelet potential of DiOHF. We therefore investigated platelet granule inhibition and potential to delay arterial thrombosis by Que and DiOHF. Both Que and DiOHF showed inhibition of collagen, adenosine diphosphate and arachidonic acid stimulated platelet aggregation, agonist-induced GPIIb/IIIa activation as demonstrated by PAC-1 and fibrinogen binding. While both flavonols inhibited agonist-induced granule exocytosis, greater inhibition of dense granule exocytosis occurred with DiOHF as measured by both ATP release and flow cytometry. In contrast, while Que inhibited agonist-induced P-selectin expression, as measured by both platelet surface P-selectin expression and upregulation of surface GPIIIa expression, inhibition by DiOHF was not significant for either parameter. C57BL/6 mice treated with 6 mg kg(-1) IV Que or DiOHF maintained greater blood flow following FeCl3-induced carotid artery injury when compared to the vehicle control. We provide evidence that Que and DiOHF improve blood flow following arterial injury in part by attenuating platelet granule exocytosis.
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Affiliation(s)
- Sapha Mosawy
- Health Innovations Research Institute, RMIT University , Melbourne , Australia
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Leo CH, Joshi A, Hart JL, Woodman OL. Endothelium-dependent nitroxyl-mediated relaxation is resistant to superoxide anion scavenging and preserved in diabetic rat aorta. Pharmacol Res 2012; 66:383-91. [PMID: 22898326 DOI: 10.1016/j.phrs.2012.07.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 07/30/2012] [Accepted: 07/30/2012] [Indexed: 10/28/2022]
Abstract
The aim of the study was to investigate whether diabetes-induced oxidant stress affects the contribution of nitroxyl (HNO) to endothelium-dependent relaxation in the rat aorta. Organ bath techniques were employed to determine vascular function of rat aorta. Pharmacological tools (3mM l-cysteine, 5mM 4-aminopyridine (4-AP), 200μM carboxy-PTIO and 100μM hydroxocobalamin, HXC) were used to distinguish between NO and HNO-mediated relaxation. Superoxide anion levels were determined by lucigenin-enhanced chemiluminescence. In the diabetic aorta, where there is increased superoxide anion production, responses to the endothelium-dependent relaxant ACh were not affected when the contribution of NO to relaxation was abolished by either HXC or carboxy-PTIO, indicating a preserved HNO-mediated relaxation. Conversely, when the contribution of HNO was inhibited with l-cysteine or 4-AP, the sensitivity and maximum relaxation to ACh was significantly decreased, suggesting that the contribution of NO was impaired by diabetes. Furthermore, whereas HNO appears to be derived from eNOS in normal aorta, in the diabetic aorta it may also arise from an eNOS-independent source, perhaps derived from nitrosothiol stores. Similarly, exposure to the superoxide anion generator, pyrogallol (100μM) significantly reduced the sensitivity to the NO donor, DEANONOate and ACh-induced NO-mediated relaxation but had no effect on responses to the HNO donor, Angeli's salt and ACh-induced HNO-mediated relaxation in the rat aorta. These findings demonstrate that NO-mediated relaxation is impaired during oxidative stress but the HNO component of relaxation is preserved under those conditions.
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Affiliation(s)
- C H Leo
- School of Medical Sciences, Health Innovations Research Institute, RMIT University, Bundoora, Victoria, Australia
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