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Coşkunsever D, Olukman M, Jannini E, Sansone A, Varrassi G. Effect of Angiotensin 1-7 Peptide Agonist AVE 0991 on Diabetic Endothelial Dysfunction in an Experimental Animal Model: A Possible Tool to Treat Diabetic Erectile Dysfunction. Cureus 2023; 15:e48770. [PMID: 38098900 PMCID: PMC10719545 DOI: 10.7759/cureus.48770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 11/13/2023] [Indexed: 12/17/2023] Open
Abstract
Background The renin-angiotensin system and its metabolites are crucial in the pathogenesis and progression of complications of diabetes. Aim In this study, we aimed to evaluate the effect of angiotensin 1-7 non-peptide agonist AVE 0991 (576 ug/kg/day i.p.) on diabetic endothelial dysfunction. Materials and methods In this experimental animal study, we investigated the effects of angiotensin 1-7 non-peptide agonist AVE 0991 (576 ug/kg/day i.p.) treatment in male Wistar rats. Diabetes was created via injecting streptozotocin (55 mg/kg/i.p., single dose). Following the cavernous tissue submaximal phenylephrine contraction, relaxation responses were obtained by applying electrical field stimulation (0.5 ms, 40 V) for 15 seconds at 2, 4, 8, 16, 32, and 64 Hz, with two-minute intervals, respectively. To evaluate the effect of nitric oxide, the responses were compared by incubating with 100 mM N(gamma)-nitro-L-arginine methyl ester (L-NAME) for 20 minutes. Additionally, Y-27632 and sodium nitroprusside responses were evaluated in tissues contracted with submaximal doses of phenylephrine. Results Following a submaximal contraction of phenylephrine in the aorta rings, relaxation responses obtained with acetylcholine, sodium nitroprusside, and Y-27632 were impaired in diabetic rats; however, significant results were obtained with treatment. Although there was no significance between the groups in the electrical field stimulation responses, there was a significant dose-dependent difference in the treatment group in this parameter after L-NAME, sodium nitroprusside, and Y-27632 relaxation. Conclusions We determined that treatment with a non-peptide receptor antagonist of angiotensin 1-7, an enzyme detected in the aortic and cavernosum endothelium, may be a promising alternative for treating the complications of diabetes.
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Affiliation(s)
| | | | | | - Andrea Sansone
- Systems Medicine, University of Rome "Tor Vergata", Rome, ITA
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Leo CH, Ou JLM, Ong ES, Qin CX, Ritchie RH, Parry LJ, Ng HH. Relaxin elicits renoprotective actions accompanied by increasing bile acid levels in streptozotocin-induced diabetic mice. Biomed Pharmacother 2023; 162:114578. [PMID: 36996678 DOI: 10.1016/j.biopha.2023.114578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 03/19/2023] [Accepted: 03/21/2023] [Indexed: 03/30/2023] Open
Abstract
BACKGROUND The peptide hormone relaxin has potent anti-fibrotic and anti-inflammatory properties in various organs, including the kidneys. However, the protective effects of relaxin in the context of diabetic kidney complications remain controversial. Here, we aimed to evaluate the effects of relaxin treatment on key markers of kidney fibrosis, oxidative stress, and inflammation and their subsequent impact on bile acid metabolism in the streptozotocin-induced diabetes mouse model. METHODS AND RESULTS Male mice were randomly allocated to placebo-treated control, placebo-treated diabetes or relaxin-treated diabetes groups (0.5 mg/kg/d, final 2 weeks of diabetes). After 12 weeks of diabetes or sham, the kidney cortex was harvested for metabolomic and gene expression analyses. Diabetic mice exhibited significant hyperglycaemia and increased circulating levels of creatine, hypoxanthine and trimethylamine N-oxide in the plasma. This was accompanied by increased expression of key markers of oxidative stress (Txnip), inflammation (Ccl2 and Il6) and fibrosis (Col1a1, Mmp2 and Fn1) in the diabetic kidney cortex. Relaxin treatment for the final 2 weeks of diabetes significantly reduced these key markers of renal fibrosis, inflammation, and oxidative stress in diabetic mice. Furthermore, relaxin treatment significantly increased the levels of bile acid metabolites, deoxycholic acid and sodium glycodeoxycholic acid, which may in part contribute to the renoprotective action of relaxin in diabetes. CONCLUSION In summary, this study shows the therapeutic potential of relaxin and that it may be used as an adjunctive treatment for diabetic kidney complications.
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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: 13] [Impact Index Per Article: 13.0] [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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Valorization of avocado seeds with antioxidant capacity using pressurized hot water extraction. Sci Rep 2022; 12:13036. [PMID: 35906278 PMCID: PMC9338084 DOI: 10.1038/s41598-022-17326-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 07/25/2022] [Indexed: 02/07/2023] Open
Abstract
The pulp of avocado (Persea Americana) is widely consumed as the primary food source, while the seed is often discarded as food waste. Increased consumption of avocado would inevitably results in production of waste by-products such as avocado seeds, hence the ability to extract phytochemicals from such waste, and upcycling to potential nutraceutical products is of great interest. The overall aim of this study is to explore avocado seeds as potential functional food through the combined use of a green extraction method, chemical standardization and pattern recognition tools, and biological characterization assays. Specifically, this study utilized an organic solvent-free extraction method, pressurized hot water extraction (PHWE) to extract phytochemicals from avocado seeds and liquid chromatography mass spectrometry (LCMS) was used to identify the phytochemicals present in the avocado seeds. Our results demonstrated that avocado seed extracts have antioxidant activity and inhibited oxidative stress-induced metabolomics changes in endothelial cells, suggesting that avocado seed extracts have vasoprotective actions.
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Sonobe T, Tsuchimochi H, Maeda H, Pearson JT. Increased contribution of KCa channels to muscle contraction induced vascular and blood flow responses in sedentary and exercise trained ZFDM rats. J Physiol 2022; 600:2919-2938. [PMID: 35551673 DOI: 10.1113/jp282981] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 05/04/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Microvascular dysfunction in type 2 diabetes impairs blood flow redistribution during exercise and limits the performance of skeletal muscle and may cause early fatigability. Endothelium-dependent hyperpolarization (EDH), which mediates vasodilation in resistance arteries is known to be depressed in animals with diabetes. Here we report that low-intensity exercise training in ZFDM rats increased KCa channel-derived component in the vasodilator responses to muscle contraction than in sedentary rats, partly due to the increase in KCNN3 expression. These results suggest that low-intensity exercise training improves blood flow redistribution in contracting skeletal muscle in metabolic disease with diabetes via upregulation of EDH. ABSTRACT In resistance arteries, endothelium-dependent hyperpolarization (EDH) mediated vasodilation is depressed in diabetes. We hypothesized that downregulation of KCa channel derived EDH reduces exercise-induced vasodilation and blood flow redistribution in diabetes. To test this hypothesis, we evaluated vascular function in response to hindlimb muscle contraction, and the contribution of KCa channels in anaesthetised ZFDM, metabolic disease rats with type 2 diabetes. We also tested whether exercise training ameliorated the vascular response. Using in vivo microangiography, the hindlimb vasculature was visualized before and after rhythmic muscle contraction (0.5 s tetanus every 3 sec, 20 times) evoked by sciatic nerve stimulation (40 Hz). Femoral blood flow of the contracting hindlimb was simultaneously measured by an ultrasonic flowmeter. The contribution of KCa channels was investigated in the presence and absence of apamin and charybdotoxin. We found that vascular and blood flow responses to muscle contraction were significantly impaired at the level of small artery segments in ZFDM fa/fa rats compared to its lean control fa/+ rats. The contribution of KCa channels was also smaller in fa/fa than in fa/+ rats. Low-intensity exercise training for 12 weeks in fa/fa rats demonstrated minor changes in the vascular and blood flow response to muscle contraction. However, KCa-derived component in the response to muscle contraction was much greater in exercise trained than in sedentary fa/fa rats. These data suggest that exercise training increases the contribution of KCa channels among endothelium-dependent vasodilatory mechanisms to maintain vascular and blood flow responses to muscle contraction in this metabolic disease rat model. Abstract figure legend Low-intensity exercise training in ZFDM, metabolic disease rats with type 2 diabetes increases KCa channel-derived component of endothelium-dependent hyperpolarization in the vascular and blood flow responses to skeletal muscle contraction than the responses in sedentary rats, partly due to upregulation of KCNN3 protein expression. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Takashi Sonobe
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Hirotsugu Tsuchimochi
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Hisashi Maeda
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - James T Pearson
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan.,Victoria Heart Institute and Monash Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, Australia
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Velagic A, Li JC, Qin CX, Li M, Deo M, Marshall SA, Anderson D, Woodman OL, Horowitz JD, Kemp-Harper BK, Ritchie RH. Cardioprotective Actions of Nitroxyl Donor Angeli's Salt are Preserved in the Diabetic Heart and Vasculature in the Face of Nitric Oxide Resistance. Br J Pharmacol 2022; 179:4117-4135. [PMID: 35365882 PMCID: PMC9540873 DOI: 10.1111/bph.15849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 02/14/2022] [Accepted: 03/09/2022] [Indexed: 11/29/2022] Open
Abstract
Background and Purpose The risk of fatal cardiovascular events is increased in patients with type 2 diabetes mellitus (T2DM). A major contributor to poor prognosis is impaired nitric oxide (NO•) signalling at the level of tissue responsiveness, termed NO• resistance. This study aimed to determine if T2DM promotes NO• resistance in the heart and vasculature and whether tissue responsiveness to nitroxyl (HNO) is affected. Experimental Approach At 8 weeks of age, male Sprague–Dawley rats commenced a high‐fat diet. After 2 weeks, the rats received low‐dose streptozotocin (two intraperitoneal injections, 35 mg·kg−1, over two consecutive days) and continued on the same diet. Twelve weeks later, isolated hearts were Langendorff‐perfused to assess responses to the NO• donor diethylamine NONOate (DEA/NO) and the HNO donor Angeli's salt. Isolated mesenteric arteries were utilised to measure vascular responsiveness to the NO• donors sodium nitroprusside (SNP) and DEA/NO, and the HNO donor Angeli's salt. Key Results Inotropic, lusitropic and coronary vasodilator responses to DEA/NO were impaired in T2DM hearts, whereas responses to Angeli's salt were preserved or enhanced. Vasorelaxation to Angeli's salt was augmented in T2DM mesenteric arteries, which were hyporesponsive to the relaxant effects of SNP and DEA/NO. Conclusion and Implications This is the first evidence that inotropic and lusitropic responses are preserved, and NO• resistance in the coronary and mesenteric vasculature is circumvented, by the HNO donor Angeli's salt in T2DM. These findings highlight the cardiovascular therapeutic potential of HNO donors, especially in emergencies such as acute ischaemia or heart failure.
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Affiliation(s)
- Anida Velagic
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Jasmin Chendi Li
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Cheng Xue Qin
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Mandy Li
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Melbourne, VIC, Australia
| | - Minh Deo
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Sarah A Marshall
- The Ritchie Centre, Department of Obstetrics and Gynaecology, School of Clinical Sciences, Monash University, VIC, Australia
| | - Dovile Anderson
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - Owen L Woodman
- Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia
| | - John D Horowitz
- Basil Hetzel Institute, Queen Elizabeth Hospital, University of Adelaide, SA, Australia
| | - Barbara K Kemp-Harper
- Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Melbourne, VIC, Australia
| | - Rebecca H Ritchie
- Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, VIC, Australia.,Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Melbourne, VIC, Australia
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da Rosa-Junior NT, Parmeggiani B, Glänzel NM, de Moura Alvorcem L, Brondani M, Britto R, Grings M, Ortiz VD, Turck P, da Rosa Araujo AS, Wajner M, Leipnitz G. Antioxidant system disturbances and mitochondrial dysfunction induced by 3-methyglutaric acid in rat heart are prevented by bezafibrate. Eur J Pharmacol 2022; 924:174950. [DOI: 10.1016/j.ejphar.2022.174950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 03/25/2022] [Accepted: 04/05/2022] [Indexed: 11/30/2022]
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9
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Metabolic regulation and dysregulation of endothelial small conductance calcium activated potassium channels. Eur J Cell Biol 2022; 101:151208. [DOI: 10.1016/j.ejcb.2022.151208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 02/06/2022] [Accepted: 02/07/2022] [Indexed: 12/13/2022] Open
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Griffiths K, Madhani M. The Use of Wire Myography to Investigate Vascular Tone and Function. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2022; 2419:361-376. [PMID: 35237977 DOI: 10.1007/978-1-0716-1924-7_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Wire myography enables the investigation of vascular tone and function of small vessels. The vessel of interest is harvested from the experimental model of choice, and then mounted as ring preparations onto a four-channel wire myograph. This technique enables ex vivo measurements of isometric response of vessels to different pharmacological agents. Here we describe in detail how to dissect, mount, and normalize vessels for the wire myography technique. We will also provide examples of how to construct concentration-response curves to a contractile and vasodilatory pharmacological agent.
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Affiliation(s)
- Kayleigh Griffiths
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Melanie Madhani
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
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Wee CL, Mokhtar SS, Banga Singh KK, Rasool AHG. Vitamin D deficiency attenuates endothelial function by reducing antioxidant activity and vascular eNOS expression in the rat microcirculation. Microvasc Res 2021; 138:104227. [PMID: 34324883 DOI: 10.1016/j.mvr.2021.104227] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 07/05/2021] [Accepted: 07/20/2021] [Indexed: 11/16/2022]
Abstract
This study examined the effects of vitamin D deficiency on vascular function and tissue oxidative status in the microcirculation; and whether or not these effects can be ameliorated with calcitriol, the active vitamin D metabolite. Three groups (n = 10 each) of male Sprague Dawley rats were fed for 10 weeks with control diet (CR), vitamin D-deficient diet without (DR), or with oral calcitriol supplementation (0.15 μg/kg) for the last four weeks (DSR). After 10 weeks, rats were sacrificed; mesenteric arterial rings were studied using wire myograph. Oxidative stress biomarkers malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity were measured in the mesenteric arterial tissue. Vascular protein expression of endothelial nitric oxide synthase (eNOS) was determined by Western blotting. Acetylcholine-induced endothelium-dependent relaxation of DR was lower than CR. eNOS expression and SOD activity were lower in mesenteric arterial tissue of DR compared to CR. Calcitriol supplementation to DSR did not ameliorate the above parameters; in fact, augmented endothelium-dependent contraction was observed. Serum calcium was higher in DSR compared to CR and DR. In conclusion, vitamin D deficiency impaired microvascular vasodilation, associated with eNOS downregulation and reduced antioxidant activity. Calcitriol supplementation to vitamin D-deficient rats at the dosage used augmented endothelium-dependent contraction, possibly due to hypercalcaemia.
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Affiliation(s)
- Chee Lee Wee
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia (Health Campus), 16150 Kota Bharu, Kelantan, Malaysia
| | - Siti Safiah Mokhtar
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia (Health Campus), 16150 Kota Bharu, Kelantan, Malaysia
| | - Kirnpal Kaur Banga Singh
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia (Health Campus), 16150 Kota Bharu, Kelantan, Malaysia
| | - Aida Hanum Ghulam Rasool
- Department of Pharmacology, School of Medical Sciences, Universiti Sains Malaysia (Health Campus), 16150 Kota Bharu, Kelantan, Malaysia.
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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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Akther F, Razan MR, Shaligram S, Graham JL, Stanhope KL, Allen KN, Vázquez-Medina JP, Havel PJ, Rahimian R. Potentiation of Acetylcholine-Induced Relaxation of Aorta in Male UC Davis Type 2 Diabetes Mellitus (UCD-T2DM) Rats: Sex-Specific Responses. Front Physiol 2021; 12:616317. [PMID: 34366875 PMCID: PMC8339592 DOI: 10.3389/fphys.2021.616317] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 05/20/2021] [Indexed: 11/13/2022] Open
Abstract
Previous reports suggest that diabetes may differentially affect the vascular beds of females and males. The objectives of this study were to examine whether there were (1) sex differences in aortic function and (2) alterations in the relative contribution of endothelium-derived relaxing factors in modulating aortic reactivity in UC Davis Type 2 Diabetes Mellitus (UCD-T2DM) rats. Endothelium-dependent vasorelaxation (EDV) in response to acetylcholine (ACh) was measured in aortic rings before and after exposure to pharmacological inhibitors. Relaxation responses to sodium nitroprusside were assessed in endothelium-denuded rings. Moreover, contractile responses to phenylephrine (PE) were measured before and after incubation of aortic rings with a nitric oxide synthase (NOS) inhibitor in the presence of indomethacin. Metabolic parameters and expression of molecules associated with vascular and insulin signaling as well as reactive oxygen species generation were determined. Diabetes slightly but significantly impaired EDV in response to ACh in aortas from females but potentiated the relaxation response in males. The potentiation of EDV in diabetic male aortas was accompanied by a traces of nitric oxide (NO)- and prostanoid-independent relaxation and elevated aortic expression of small- and intermediate conductance Ca2+-activated K+ channels in this group. The smooth muscle sensitivity to NO was not altered, whereas the responsiveness to PE was significantly enhanced in aortas of diabetic groups in both sexes. Endothelium-derived NO during smooth muscle contraction, as assessed by the potentiation of the response to PE after NOS inhibition, was reduced in aortas of diabetic rats regardless of sex. Accordingly, decreases in pAkt and peNOS were observed in aortas from diabetic rats in both sexes compared with controls. Our data suggest that a decrease in insulin sensitivity via pAkt-peNOS-dependent signaling and an increase in oxidative stress may contribute to the elevated contractile responses observed in diabetic aortas in both sexes. This study demonstrates that aortic function in UCD-T2DM rats is altered in both sexes. Here, we provide the first evidence of sexual dimorphism in aortic relaxation in UCD-T2DM rats.
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Affiliation(s)
- Farjana Akther
- Department of Physiology & Pharmacology, Thomas J. Long School of Pharmacy, University of the Pacific, Stockton, CA, United States
| | - Md Rahatullah Razan
- Department of Physiology & Pharmacology, Thomas J. Long School of Pharmacy, University of the Pacific, Stockton, CA, United States
| | - Sonali Shaligram
- Department of Physiology & Pharmacology, Thomas J. Long School of Pharmacy, University of the Pacific, Stockton, CA, United States
| | - James L. Graham
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
- Department of Nutrition, University of California, Davis, Davis, CA, United States
| | - Kimber L. Stanhope
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
- Department of Nutrition, University of California, Davis, Davis, CA, United States
| | - Kaitlin N. Allen
- Department of Integrative Biology, University of California, Berkeley, Berkeley, CA, United States
| | | | - Peter J. Havel
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
- Department of Nutrition, University of California, Davis, Davis, CA, United States
| | - Roshanak Rahimian
- Department of Physiology & Pharmacology, Thomas J. Long School of Pharmacy, University of the Pacific, Stockton, CA, United States
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Kornyushin OV, Sonin DL, Polozov AS, Masley VV, Istomina MS, Papayan GV, Mukhametdinova DV, Cheburkin YV, Toropova YG, Zelinskaya IA, Neimark AE, Derkach KV, Shpakov AO, Galagudza MM. Effects of three types of bariatric interventions on myocardial infarct size and vascular function in rats with type 2 diabetes mellitus. Life Sci 2021; 279:119676. [PMID: 34087285 DOI: 10.1016/j.lfs.2021.119676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 05/21/2021] [Accepted: 05/26/2021] [Indexed: 12/20/2022]
Abstract
AIMS The effects of three types of bariatric interventions on myocardial infarct size were tested in the rat model of type 2 diabetes mellitus (T2DM). We also evaluated the effects of bariatric surgery on no-reflow phenomenon and vascular dysfunction caused by T2DM. MAIN METHODS Rats with T2DM were assigned into groups: without surgery, sham-operated, ileal transposition, Roux-en-Y gastric bypass, and sleeve gastrectomy. Oral glucose tolerance, glucagon-like peptide-1, and insulin levels were measured. Six weeks after surgery, the animals were subjected to myocardial ischemia-reperfusion followed by histochemical determination of infarct size (IS), no-reflow zone, and blood stasis area size. Vascular dysfunction was characterized using wire myography. KEY FINDINGS All bariatric surgery types caused significant reductions in animal body weight and resulted in T2DM compensation. All bariatric interventions partially normalized glucagon-like peptide-1 responses attenuated by T2DM. IS was significantly smaller in animals with T2DM. Bariatric surgery provided no additional IS limitation compared with T2DM alone. Bariatric surgeries reversed T2DM-induced enhanced contractile responses of the mesenteric artery to 5-hydroxytryptamine. Sleeve gastrectomy normalized decreased nitric oxide synthase contribution to the endothelium-dependent vasodilatation in T2DM. SIGNIFICANCE T2DM resulted in a reduction of infarct size and no-reflow zone size. Bariatric surgery provided no additional infarct-limiting effect, but it normalized T2DM-induced augmented vascular contractility and reversed decreased contribution of nitric oxide to endothelium-dependent vasodilatation typical of T2DM. All taken together, we suggest that this type of surgery may have a beneficial effect on T2DM-induced cardiovascular diseases.
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Affiliation(s)
- Oleg V Kornyushin
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Saint Petersburg, Russian Federation
| | - Dmitry L Sonin
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Saint Petersburg, Russian Federation
| | - Alexander S Polozov
- Laboratory of Physiology Nutrition, Pavlov Institute of Physiology RAS, Saint Petersburg, Russian Federation
| | - Vitaly V Masley
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Saint Petersburg, Russian Federation
| | - Maria S Istomina
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Saint Petersburg, Russian Federation
| | - Garry V Papayan
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Saint Petersburg, Russian Federation
| | - Daria V Mukhametdinova
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Saint Petersburg, Russian Federation
| | - Yuri V Cheburkin
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Saint Petersburg, Russian Federation
| | - Yana G Toropova
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Saint Petersburg, Russian Federation
| | - Irina A Zelinskaya
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Saint Petersburg, Russian Federation
| | - Alexander E Neimark
- Laboratory of Surgery for Metabolic Disorders, Almazov National Medical Research Centre, Saint Petersburg, Russian Federation
| | - Kira V Derkach
- Laboratory of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russian Federation
| | - Alexander O Shpakov
- Laboratory of Molecular Endocrinology and Neurochemistry, Sechenov Institute of Evolutionary Physiology and Biochemistry, Saint Petersburg, Russian Federation
| | - Michael M Galagudza
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Saint Petersburg, Russian Federation.
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15
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Li X, Liu Y, Cao A, Li C, Wang L, Wu Q, Li X, Lv X, Zhu J, Chun H, Laba C, Du X, Zhang Y, Yang H. Crocin Improves Endothelial Mitochondrial Dysfunction via GPx1/ROS/KCa3.1 Signal Axis in Diabetes. Front Cell Dev Biol 2021; 9:651434. [PMID: 33777959 PMCID: PMC7994751 DOI: 10.3389/fcell.2021.651434] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 02/10/2021] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial dysfunction contributes to excessive reactive oxygen species (ROS) generation, which is a dramatic cause to promote endothelial dysfunction in diabetes. It was previously demonstrated that crocin protected the endothelium based on its diverse medicinal properties, but its effect on the mitochondrion and the potential mechanism are not fully understood. In this study, mitochondrial function was analyzed during the process of excessive ROS generation in high glucose (HG)-cultured human umbilical vein endothelial cells (HUVECs). The role played by KCa3.1 was further investigated by the inhibition and/or gene silence of KCa3.1 in this process. In addition, nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase 2 (NOX2), superoxide dismutase 1 (SOD1), and glutathione peroxidase 1 (GPx1) were also detected in this study. Our data showed that crocin improved mitochondrial dysfunction and maintained normal mitochondrial morphology by enhancing the mitochondrial membrane potential (MMP), mitochondrial mass, and mitochondrial fusion. Furthermore, KCa3.1 was confirmed to be located in the mitochondrion, and the blockade and/or silencing of KCa3.1 improved mitochondrial dysfunction and reduced excessive ROS generation but did not affect NOX2 and/or the SOD1 system. Intriguingly, it was confirmed that KCa3.1 expression was elevated by ROS overproduction in the endothelium under HG and/or diabetes conditions, while crocin significantly suppressed this elevation by promoting GPx1 and subsequently eliminating ROS generation. In addition, crocin enhanced CD31, thrombomodulin (TM), and p-/t-endothelial nitric oxide synthase (eNOS) expressions as well as NO generation and decreased vascular tone. Hence, crocin improved mitochondrial dysfunction through inhibiting ROS-induced KCa3.1 overexpression in the endothelium, which in turn reduced more ROS generation and final endothelial dysfunction in diabetes.
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Affiliation(s)
- Xuemei Li
- Department of Anatomy, Harbin Medical University, Harbin, China
| | - Yang Liu
- Department of Anatomy, Heilongjiang University of Chinese Medicine, Harbin, China
| | - Anqiang Cao
- Department of Cardiac Surgery, The Third People's Hospital of Chengdu, Institute of Cardiovascular Science, Chengdu, China
| | - Chao Li
- Department of Anatomy, Harbin Medical University, Harbin, China
| | - Luodan Wang
- Department of Anatomy, Harbin Medical University, Harbin, China
| | - Qing Wu
- Department of Anatomy, Harbin Medical University, Harbin, China
| | - Xinlei Li
- Department of Anatomy, Harbin Medical University, Harbin, China
| | - Xiaohong Lv
- Department of Anatomy, Harbin Medical University, Harbin, China
| | - Jiwei Zhu
- Department of Forensic Medicine, Harbin Medical University, Harbin, China
| | - Hua Chun
- Department of Modern Medicine, Tibetan Traditional Medical College, Lhasa, China
| | - Ciren Laba
- Department of Modern Medicine, Tibetan Traditional Medical College, Lhasa, China
| | - Xingchi Du
- Department of Anatomy, Harbin Medical University, Harbin, China
| | - Yafang Zhang
- Department of Anatomy, Harbin Medical University, Harbin, China
| | - Huike Yang
- Department of Anatomy, Harbin Medical University, Harbin, China.,Department of Modern Medicine, Tibetan Traditional Medical College, Lhasa, China
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16
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Xing H, Zhang Z, Shi G, He Y, Song Y, Liu Y, Harrington EO, Sellke FW, Feng J. Chronic Inhibition of mROS Protects Against Coronary Endothelial Dysfunction in Mice With Diabetes. Front Cell Dev Biol 2021; 9:643810. [PMID: 33681229 PMCID: PMC7930489 DOI: 10.3389/fcell.2021.643810] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 01/29/2021] [Indexed: 11/13/2022] Open
Abstract
Diabetes is associated with coronary endothelial dysfunction. Persistent oxidative stress during diabetes contributes to coronary endothelial dysfunction. The mitochondria are main sources of reactive oxygen species (ROS) in diabetes, and mitochondria-targeted antioxidant mito-Tempo can prevent mitochondrial reactive oxygen species (mROS) generation in a variety of disorders. Inhibition/inactivation of small-conductance Ca2+-activated K+ (SK) channels contribute to diabetic downregulation of coronary endothelial function/relaxation. However, few investigated the role of mROS on endothelial dysfunction/vasodilation and endothelial SK channel downregulation in diabetes. The aim of present study was to investigate the chronic administration of mito-Tempo, on coronary vasodilation, and endothelial SK channel activity of mice with or without diabetes. Mito-Tempo (1 mg/kg/day) was applied to the mice with or without diabetes (n = 10/group) for 4 weeks. In vitro relaxation response of pre-contracted arteries was examined in the presence or absence of the vasodilatory agents. SK channel currents of the isolated mouse heart endothelial cells were measured using whole-cell patch clamp methods. At baseline, coronary endothelium-dependent relaxation responses to ADP and the selective SK channel activator NS309 and endothelial SK channel currents were decreased in diabetic mice compared with that in non-diabetic (ND) mice (p < 0.05). After a 4-week treatment with mito-Tempo, coronary endothelium-dependent relaxation response to ADP or NS309 and endothelial SK channel currents in the diabetic mice was significantly improved when compared with that in untreated diabetic mice (p < 0.05). Interestingly, coronary relaxation responses to ADP and NS309 and endothelial SK channel currents were not significantly changed in ND mice after mito-Tempo treatment, as compared to that of untreated control group. Chronic inhibition of endothelial mROS appears to improve coronary endothelial function/dilation and SK channel activity in diabetes, and mROS inhibitors may be a novel strategy to treat vascular complications in diabetes.
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Affiliation(s)
- Hang Xing
- Cardiothoracic Surgery Research Laboratory, Cardiovascular Research Center, Department of Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States
| | - Zhiqi Zhang
- Cardiothoracic Surgery Research Laboratory, Cardiovascular Research Center, Department of Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States
| | - Guangbin Shi
- Cardiothoracic Surgery Research Laboratory, Cardiovascular Research Center, Department of Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States
| | - Yixin He
- Cardiothoracic Surgery Research Laboratory, Cardiovascular Research Center, Department of Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States
| | - Yi Song
- Cardiothoracic Surgery Research Laboratory, Cardiovascular Research Center, Department of Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States
| | - Yuhong Liu
- Cardiothoracic Surgery Research Laboratory, Cardiovascular Research Center, Department of Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States
| | - Elizabeth O Harrington
- Vascular Research Laboratory, Providence VA Medical Center, Department of Medicine, Alpert Medical School of Brown University, Providence, RI, United States
| | - Frank W Sellke
- Cardiothoracic Surgery Research Laboratory, Cardiovascular Research Center, Department of Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States
| | - Jun Feng
- Cardiothoracic Surgery Research Laboratory, Cardiovascular Research Center, Department of Surgery, Rhode Island Hospital, Alpert Medical School of Brown University, Providence, RI, United States
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17
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Li JC, Velagic A, Qin CX, Li M, Leo CH, Kemp-Harper BK, Ritchie RH, Woodman OL. Diabetes Attenuates the Contribution of Endogenous Nitric Oxide but Not Nitroxyl to Endothelium Dependent Relaxation of Rat Carotid Arteries. Front Pharmacol 2021; 11:585740. [PMID: 33716721 PMCID: PMC7944142 DOI: 10.3389/fphar.2020.585740] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 12/16/2020] [Indexed: 12/27/2022] Open
Abstract
Endothelial dysfunction is a major risk factor for several of the vascular complications of diabetes, including ischemic stroke. Nitroxyl (HNO), the one electron reduced and protonated form of nitric oxide (NO•), is resistant to scavenging by superoxide, but the role of HNO in diabetes mellitus associated endothelial dysfunction in the carotid artery remains unknown. Aim: To assess how diabetes affects the role of endogenous NO• and HNO in endothelium-dependent relaxation in rat isolated carotid arteries. Methods: Male Sprague Dawley rats were fed a high-fat-diet (HFD) for 2 weeks prior to administration of low dose streptozotocin (STZ; 35 mg/kg i. p./day) for 2 days. The HFD was continued for a further 12 weeks. Sham rats were fed standard chow and administered with citrate vehicle. After 14 weeks total, rats were anesthetized and carotid arteries collected to assess responses to the endothelium-dependent vasodilator, acetylcholine (ACh) by myography. The combination of calcium-activated potassium channel blockers, TRAM-34 (1 μmol/L) and apamin (1 μmol/L) was used to assess the contribution of endothelium-dependent hyperpolarization to relaxation. The corresponding contribution of NOS-derived nitrogen oxide species to relaxation was assessed using the combination of the NO• synthase inhibitor, L-NAME (200 μmol/L) and the soluble guanylate cyclase inhibitor ODQ (10 μmol/L). Lastly, L-cysteine (3 mmol/L), a selective HNO scavenger, and hydroxocobalamin (HXC; 100 μmol/L), a NO• scavenger, were used to distinguish between NO• and HNO-mediated relaxation. Results: At study end, diabetic rats exhibited significantly retarded body weight gain and elevated blood glucose levels compared to sham rats. The sensitivity and the maximal relaxation response to ACh was significantly impaired in carotid arteries from diabetic rats, indicating endothelial dysfunction. The vasorelaxation evoked by ACh was abolished by L-NAME plus ODQ, but not affected by the apamin plus TRAM-34 combination, indicating that NOS-derived nitrogen oxide species are the predominant endothelium-derived vasodilators in sham and diabetic rat carotid arteries. The maximum relaxation to ACh was significantly decreased by L-cysteine in both sham and diabetic rats, whereas HXC attenuated ACh-induced relaxation only in sham rats, suggesting that diabetes impaired the contribution of NO•, whereas HNO-mediated vasorelaxation remained intact. Conclusion: Both NO• and HNO contribute to endothelium-dependent relaxation in carotid arteries. In diabetes, NO•-mediated relaxation is impaired, whereas HNO-mediated relaxation was preserved. The potential for preserved HNO activity under pathological conditions that are associated with oxidative stress indicates that HNO donors may represent a viable therapeutic approach to the treatment of vascular dysfunction.
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Affiliation(s)
- Jasmin Chendi Li
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
- Department of Pharmacology, University of Melbourne, Parkville, VIC, Australia
| | - Anida Velagic
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Cheng Xue Qin
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
- Department of Pharmacology, University of Melbourne, Parkville, VIC, Australia
| | - Mandy Li
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Department of Pharmacology, Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Chen Huei Leo
- Science, Maths and Technology Cluster, Singapore University of Technology & Design, Singapore, Singapore
| | - Barbara K. Kemp-Harper
- Department of Pharmacology, Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Rebecca H. Ritchie
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
- Department of Pharmacology, University of Melbourne, Parkville, VIC, Australia
- Department of Pharmacology, Cardiovascular Disease Program, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Owen L. Woodman
- Drug, Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
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18
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Yeoh BS, Omar N, Mohammad M, Mokhtar SS, Ahmad R. Antioxidative Propolis From Stingless Bees (Heterotrigona Itama) Preserves Endothelium-Dependent Aortic Relaxation of Diabetic Rats: The Role of Nitric Oxide and Cyclic Guanosine Monophosphate. BRAZ J PHARM SCI 2021. [DOI: 10.1590/s2175-97902020000419187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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19
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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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20
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Matsumoto T, Takayanagi K, Kojima M, Taguchi K, Kobayashi T. Toll-Like Receptor 4 Inhibitor TAK-242 Augments Acetylcholine-Induced Relaxation in Superior Mesenteric Arteries of the Streptozotocin-Induced Diabetic Rat. Biol Pharm Bull 2020; 43:1283-1287. [DOI: 10.1248/bpb.b20-00328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Takayuki Matsumoto
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Keisuke Takayanagi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Mihoka Kojima
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Kumiko Taguchi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
| | - Tsuneo Kobayashi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University
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21
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Investigating the effect of some fluoroquinolones on C-reactive protein levels and ACh-Induced blood pressure reduction deviations after aging of diabetes in STZ-Induced diabetic wistar rats. Heliyon 2020; 6:e03812. [PMID: 32368653 PMCID: PMC7186571 DOI: 10.1016/j.heliyon.2020.e03812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/22/2019] [Accepted: 04/16/2020] [Indexed: 11/22/2022] Open
Abstract
The treatment of infections in diabetic patients by fluoroquinolone antibiotics is associated with a reduced risk of coronary artery disease, and may improve endothelium-derived hyperpolarizing factor (EDHF) efficacy. The inflammatory marker C-reactive protein (CRP) is an important predictor of cardiovascular events, and vascular endothelium dysfunction, which makes this marker a target for drug-based treatment. This study aims to investigate the relation between the treatment by fluoroquinolones with CRP plasma levels, as well as acetylecholine (ACh)-induced small conductance calcium-activated potassium channels (SKCa)-dependent blood pressure (BP) reduction deviations in wistar rats after inducing a type 2-like diabetes with aging state after four months of streptozotocin (STZ) injection. Experimental animals were divided into four groups, group 1: diabetic animals were treated with moxifloxacin (n = 15), group 2: diabetic animals were treated with levofloxacin (n = 15), group 3: diabetic control animals (n = 15), and group 4: non-diabetic control animals (n = 6). The levels of plasma CRP, as well as ACh-induced SKCa-dependent BP reduction deviations were compared four months after the development of diabetes, after that; two groups were treated with fluoroquinolones, four months after the treatment; CRP-plasma levels, as well as ACh-induced SKCa-dependent BP reduction deviations were also evaluated and compared for all groups. Sustained hyperglycemia after the induction of diabetes elevated CRP plasma levels, and reduced ACh-induced SKCa-dependent BP reduction, observed diabetes-induced variations were minimal in fluoroquinolones treated diabetic groups compared with diabetic control group, In conclusion, the treatment with fluoroquinolone antibiotics in diabetic wistars may be associated with a lowering in CRP levels progression, and improvement in SKCa vitality, which indicates the importance of treating infections in diabetics by fluoroquinolones to mitigate some vascular complications signs that lead to morbidity and mortality in diabetes.
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22
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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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23
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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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24
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Leo CH, Ng HH, Marshall SA, Jelinic M, Rupasinghe T, Qin C, Roessner U, Ritchie RH, Tare M, Parry LJ. Relaxin reduces endothelium-derived vasoconstriction in hypertension: Revealing new therapeutic insights. Br J Pharmacol 2019; 177:217-233. [PMID: 31479151 DOI: 10.1111/bph.14858] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 08/21/2019] [Accepted: 08/26/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND AND PURPOSE Endothelium-derived vasoconstriction is a hallmark of vascular dysfunction in hypertension. In some cases, an overproduction of endothelium-derived prostacyclin (PGI2 ) can cause contraction rather than relaxation. Relaxin is well known for its vasoprotective actions, but the possibility that this peptide could also reverse endothelium-derived vasoconstriction has never been investigated. We tested the hypothesis that short-term relaxin treatment mitigates endothelium-derived vasoconstriction in spontaneously hypertensive rats (SHR). EXPERIMENTAL APPROACH Male Wistar Kyoto rats (WKY) and SHR were subcutaneously infused with either vehicle (20 mmol·L-1 sodium acetate) or relaxin (13.3 μg·kg-1 ·hr-1 ) using osmotic minipumps for 3 days. Vascular reactivity to the endothelium-dependent agonist ACh was assessed in vitro by wire myography. Quantitative PCR and LC-MS were used to identify changes in gene expression of prostanoid pathways and PG production, respectively. KEY RESULTS Relaxin treatment ameliorated hypertension-induced endothelial dysfunction by increasing NO-dependent relaxation and reducing endothelium-dependent contraction. Notably, short-term relaxin treatment up-regulated mesenteric PGI2 receptor (IP) expression, permitting PGI2 -IP-mediated vasorelaxation. In the aorta, reversal of contraction was accompanied by suppression of the hypertension-induced increase in prostanoid-producing enzymes and reduction in PGI2 -evoked contractions. CONCLUSIONS AND IMPLICATIONS Relaxin has region-dependent vasoprotective actions in hypertension. Specifically, relaxin has distinct effects on endothelium-derived contracting factors and their associated vasoconstrictor pathways in mesenteric arteries and the aorta. Taken together, these observations reveal the potential of relaxin as a new therapeutic agent for vascular disorders that are associated with endothelium-derived vasoconstriction including hypertension.
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Affiliation(s)
- Chen Huei Leo
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Hooi Hooi Ng
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia.,Heart Failure Pharmacology, Baker Heart & Diabetes Institute, Melbourne, VIC, Australia
| | - Sarah A Marshall
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Maria Jelinic
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Thusitha Rupasinghe
- Metabolomics Australia, School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Chengxue Qin
- Heart Failure Pharmacology, Baker Heart & Diabetes Institute, Melbourne, VIC, Australia.,Department of Pharmacology & Therapeutics, The University of Melbourne, Parkville, VIC, Australia
| | - Ute Roessner
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia.,Metabolomics Australia, School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
| | - Rebecca H Ritchie
- Heart Failure Pharmacology, Baker Heart & Diabetes Institute, Melbourne, VIC, Australia.,Department of Diabetes, Monash University, Clayton, VIC, Australia
| | - Marianne Tare
- Monash Rural Health, Monash University, Churchill, VIC, Australia.,Department of Physiology, Monash University, Clayton, VIC, Australia
| | - Laura J Parry
- School of Biosciences, The University of Melbourne, Parkville, VIC, Australia
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25
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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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Angulo J, El Assar M, Sevilleja-Ortiz A, Fernández A, Sánchez-Ferrer A, Romero-Otero J, Martínez-Salamanca JI, La Fuente JM, Rodríguez-Mañas L. Short-term pharmacological activation of Nrf2 ameliorates vascular dysfunction in aged rats and in pathological human vasculature. A potential target for therapeutic intervention. Redox Biol 2019; 26:101271. [PMID: 31302408 PMCID: PMC6626891 DOI: 10.1016/j.redox.2019.101271] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 06/28/2019] [Accepted: 07/04/2019] [Indexed: 12/11/2022] Open
Abstract
Oxidative stress contributes to endothelial dysfunction, a key step in cardiovascular disease development. Ageing-related vascular dysfunction involves defective antioxidant response. Nuclear factor erythroid 2-like-2 (Nrf2), orchestrates cellular response to oxidative stress. We evaluated the impact of Nrf2-activation on endothelium-dependent and H2O2-mediated vasodilations in: aorta (RA), mesenteric artery (RMA), coronary artery (RCA) and corpus cavernosum (RCC) from ageing rats and in human penile arteries (HPRA) and corpus cavernosum (HCC) from erectile dysfunction (ED) patients. Relaxant responses were evaluated in organ chambers and wire myographs. Nrf2 content and heme oxygenase-1 (HO-1) were determined by ELISA. Superoxide and Nrf2 were detected by immunofluorescence. Pharmacological activation of Nrf2 with sulforaphane (SFN) improved NO- and endothelium-derived hyperpolarizing factor-mediated endothelium-dependent vasodilation and H2O2-induced relaxation in vascular beds from aging rats. SFN-induced effects were associated with increased Nrf2 (RMA, RCA) and reduced superoxide detection in RCA. Improvement of vascular function was confirmed in HPRA and HCC from ED patients and mimicked by another Nrf2 activator, oltipraz. Nrf2 increase and superoxide reduction together with HO-1 increase by Nrf2 activation was evidenced in HCC from ED patients. PDE5 inhibitor-induced relaxations of HPRA and HCC from ED patients were enhanced by SFN. Nrf2 short-term pharmacological activation attenuates age-related impairment of endothelium-dependent and reactive oxygen species (ROS)-induced vasodilation in different rat and human vascular territories by upregulation of Nrf2-related signaling and decreased oxidative stress. In ED patients target tissues, Nrf2 potentiates the functional effect of ED conventional pharmacological therapy suggesting potential therapeutic implication.
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Affiliation(s)
- Javier Angulo
- Servicio de Histología-Investigación, Unidad de Investigación Traslacional en Cardiología (IRYCIS-UFV), Hospital Ramón y Cajal, Madrid, Spain; Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain
| | - Mariam El Assar
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain; Fundación para la Investigación Biomédica del Hospital Universitario de Getafe, Getafe, Spain
| | - Alejandro Sevilleja-Ortiz
- Servicio de Histología-Investigación, Unidad de Investigación Traslacional en Cardiología (IRYCIS-UFV), Hospital Ramón y Cajal, Madrid, Spain
| | - Argentina Fernández
- Servicio de Histología-Investigación, Unidad de Investigación Traslacional en Cardiología (IRYCIS-UFV), Hospital Ramón y Cajal, Madrid, Spain
| | - Alberto Sánchez-Ferrer
- Fundación para la Investigación Biomédica del Hospital Universitario de Getafe, Getafe, Spain
| | | | | | | | - Leocadio Rodríguez-Mañas
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain; Fundación para la Investigación Biomédica del Hospital Universitario de Getafe, Getafe, Spain; Servicio de Geriatría, Hospital Universitario de Getafe, Getafe, Spain.
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27
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Behringer EJ, Hakim MA. Functional Interaction among K Ca and TRP Channels for Cardiovascular Physiology: Modern Perspectives on Aging and Chronic Disease. Int J Mol Sci 2019; 20:ijms20061380. [PMID: 30893836 PMCID: PMC6471369 DOI: 10.3390/ijms20061380] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 03/07/2019] [Accepted: 03/15/2019] [Indexed: 12/16/2022] Open
Abstract
Effective delivery of oxygen and essential nutrients to vital organs and tissues throughout the body requires adequate blood flow supplied through resistance vessels. The intimate relationship between intracellular calcium ([Ca2+]i) and regulation of membrane potential (Vm) is indispensable for maintaining blood flow regulation. In particular, Ca2+-activated K+ (KCa) channels were ascertained as transducers of elevated [Ca2+]i signals into hyperpolarization of Vm as a pathway for decreasing vascular resistance, thereby enhancing blood flow. Recent evidence also supports the reverse role for KCa channels, in which they facilitate Ca2+ influx into the cell interior through open non-selective cation (e.g., transient receptor potential; TRP) channels in accord with robust electrical (hyperpolarization) and concentration (~20,000-fold) transmembrane gradients for Ca2+. Such an arrangement supports a feed-forward activation of Vm hyperpolarization while potentially boosting production of nitric oxide. Furthermore, in vascular types expressing TRP channels but deficient in functional KCa channels (e.g., collecting lymphatic endothelium), there are profound alterations such as downstream depolarizing ionic fluxes and the absence of dynamic hyperpolarizing events. Altogether, this review is a refined set of evidence-based perspectives focused on the role of the endothelial KCa and TRP channels throughout multiple experimental animal models and vascular types. We discuss the diverse interactions among KCa and TRP channels to integrate Ca2+, oxidative, and electrical signaling in the context of cardiovascular physiology and pathology. Building from a foundation of cellular biophysical data throughout a wide and diverse compilation of significant discoveries, a translational narrative is provided for readers toward the treatment and prevention of chronic, age-related cardiovascular disease.
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Affiliation(s)
- Erik J Behringer
- Department of Basic Sciences, 11041 Campus Street, Risley Hall, Loma Linda University, Loma Linda, CA 92350, USA.
| | - Md A Hakim
- Department of Basic Sciences, 11041 Campus Street, Risley Hall, Loma Linda University, Loma Linda, CA 92350, USA.
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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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29
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Gojkovic-Bukarica L, Markovic-Lipkovski J, Heinle H, Cirovic S, Rajkovic J, Djokic V, Zivanovic V, Bukarica A, Novakovic R. The red wine polyphenol resveratrol induced relaxation of the isolated renal artery of diabetic rats: The role of potassium channels. J Funct Foods 2019. [DOI: 10.1016/j.jff.2018.11.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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30
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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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31
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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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32
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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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33
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Wiest EF, Walsh-Wilcox MT, Walker MK. Omega-3 Polyunsaturated Fatty Acids Protect Against Cigarette Smoke-Induced Oxidative Stress and Vascular Dysfunction. Toxicol Sci 2018; 156:300-310. [PMID: 28115642 DOI: 10.1093/toxsci/kfw255] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In cigarette smokers endothelial dysfunction, measured by flow-mediated dilation (FMD), precedes cardiovascular disease (CVD) and can be improved by supplementation with n - 3 polyunsaturated fatty acids (PUFAs). We developed a mouse model of cigarette smoke (CS)-induced endothelial dysfunction that resembles impaired FMD observed in human cigarette smokers and investigated the mechanism by which n - 3 PUFAs mediate vasoprotection. We hypothesized that loss of nitric oxide (NO)-dependent vasodilation in CS-exposed mice would be prevented by dietary n - 3 PUFAs via a decrease in oxidative stress. C57BL/6 mice were fed a chow or n - 3 PUFA diet for 8 weeks and then exposed to mainstream CS or filtered air for 5 days, 2 h/day. Mesenteric arterioles were preconstricted with U46619 and dilated by stepwise increases in pressure (0-40 mmHg), resulting in increases in flow, ± inhibitor of NO production or antioxidant, Tempol. Markers of oxidative stress were measured in lung and heart. CS-exposed mice on a chow diet had impaired FMD, resulting from loss of NO-dependent dilation, compared with air exposed mice. Tempol restored FMD by normalizing NO-dependent dilation and increasing NO-independent dilation. CS-exposed mice on the n - 3 PUFA diet had normal FMD, resulting from a significant increase in NO-independent dilation, compared with CS-exposed mice on a chow diet. Furthermore, n - 3 PUFAs decreased two CS-induced markers of oxidative stress, 8-epiprostaglandin-F2α levels and heme oxygenase-1 mRNA, and significantly attenuated CS-induced cytochrome P4501A1 mRNA expression. These data demonstrate that dietary n - 3 PUFAs can protect against CS-induced vascular dysfunction via multiple mechanisms, including increasing NO-independent vasodilation and decreasing oxidative stress.
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Affiliation(s)
- Elani F Wiest
- Department of Pharmaceutical Sciences, University of New Mexico, Albuquerque, New Mexico 87131
| | - Mary T Walsh-Wilcox
- Department of Pharmaceutical Sciences, University of New Mexico, Albuquerque, New Mexico 87131
| | - Mary K Walker
- Department of Pharmaceutical Sciences, University of New Mexico, Albuquerque, New Mexico 87131
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34
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Behringer EJ. Calcium and electrical signaling in arterial endothelial tubes: New insights into cellular physiology and cardiovascular function. Microcirculation 2018; 24. [PMID: 27801542 DOI: 10.1111/micc.12328] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 10/25/2016] [Indexed: 12/23/2022]
Abstract
The integral role of the endothelium during the coordination of blood flow throughout vascular resistance networks has been recognized for several decades now. Early examination of the distinct anatomy and physiology of the endothelium as a signaling conduit along the vascular wall has prompted development and application of an intact endothelial "tube" study model isolated from rodent skeletal muscle resistance arteries. Vasodilatory signals such as increased endothelial cell (EC) Ca2+ ([Ca2+ ]i ) and hyperpolarization take place in single ECs while shared between electrically coupled ECs through gap junctions up to distances of millimeters (≥2 mm). The small- and intermediate-conductance Ca2+ activated K+ (SKCa /IKCa or KCa 2.3/KCa 3.1) channels function at the interface of Ca2+ signaling and hyperpolarization; a bidirectional relationship whereby increases in [Ca2+ ]i activate SKCa /IKCa channels to produce hyperpolarization and vice versa. Further, the spatial domain of hyperpolarization among electrically coupled ECs can be finely tuned via incremental modulation of SKCa /IKCa channels to balance the strength of local and conducted electrical signals underlying vasomotor activity. Multifunctional properties of the voltage-insensitive SKCa /IKCa channels of resistance artery endothelium may be employed for therapy during the aging process and development of vascular disease.
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Affiliation(s)
- Erik J Behringer
- Department of Basic Sciences, Loma Linda University, Loma Linda, CA, USA
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35
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Lemmey HAL, Ye X, Ding HC, Triggle CR, Garland CJ, Dora KA. Hyperglycaemia disrupts conducted vasodilation in the resistance vasculature of db/db mice. Vascul Pharmacol 2018; 103-105:29-35. [PMID: 29339138 PMCID: PMC5906692 DOI: 10.1016/j.vph.2018.01.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 11/27/2017] [Accepted: 01/10/2018] [Indexed: 11/17/2022]
Abstract
Vascular dysfunction in small resistance arteries is observed during chronic elevations in blood glucose. Hyperglycaemia-associated effects on endothelium-dependent vasodilation have been well characterized, but effects on conducted vasodilation in the resistance vasculature are not known. Small mesenteric arteries were isolated from healthy and diabetic db/db mice, which were used as a model of chronic hyperglycaemia. Endothelium-dependent vasodilation via the Gq/11-coupled proteinase activated receptor 2 (PAR2) was stimulated with the selective agonist SLIGRL. The Ca2+-sensitive fluorescent indicator fluo-8 reported changes in endothelial cell (EC) [Ca2+]i, and triple cannulated bifurcating mesenteric arteries were used to study conducted vasodilation. Chronic hyperglycaemia did not affect either EC Ca2+ or local vasodilation to SLIGRL. However, both acute and chronic exposure to high glucose or the mannitol osmotic control attenuated conducted vasodilation to 10μM SLIGRL. This investigation demonstrates for the first time that a hypertonic solution containing glucose or mannitol can interfere with the spread of a hyperpolarizing current along the endothelium in a physiological setting. Our findings reiterate the importance of studying the effects of hyperglycaemia in the vasculature, and provide the basis for further studies regarding the modulation of junctional proteins involved in cell to cell communication by diseases such as diabetes.
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Affiliation(s)
- Hamish A L Lemmey
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
| | - Xi Ye
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
| | - Hong C Ding
- Department of Pharmacology, Weill Cornell Medicine in Qatar, P.O. Box 24144, Education City, Doha, Qatar.
| | - Christopher R Triggle
- Department of Pharmacology, Weill Cornell Medicine in Qatar, P.O. Box 24144, Education City, Doha, Qatar.
| | - Christopher J Garland
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
| | - Kim A Dora
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
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Behringer EJ, Segal SS. Impact of Aging on Calcium Signaling and Membrane Potential in Endothelium of Resistance Arteries: A Role for Mitochondria. J Gerontol A Biol Sci Med Sci 2017; 72:1627-1637. [PMID: 28510636 DOI: 10.1093/gerona/glx079] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/21/2017] [Indexed: 12/20/2022] Open
Abstract
Impaired blood flow to peripheral tissues during advanced age is associated with endothelial dysfunction and diminished bioavailability of nitric oxide (NO). However, it is unknown whether aging impacts coupling between intracellular calcium ([Ca2+]i) signaling and small- and intermediate K+ channel (SKCa/IKCa) activity during endothelium-derived hyperpolarization (EDH), a signaling pathway integral to dilation of the resistance vasculature. To address the potential impact of aging on EDH, Fura-2 photometry and intracellular recording were applied to evaluate [Ca2+]i and membrane potential of intact endothelial tubes (width, 60 µm; length, 1-3 mm) freshly isolated from superior epigastric arteries of young (4-6 mo) and old (24-26 mo) male C57BL/6 mice. In response to acetylcholine, intracellular release of Ca2+ from the endoplasmic reticulum (ER) was enhanced with aging. Further, treatment with the mitochondrial uncoupler FCCP evoked a significant increase of [Ca2+]i with membrane hyperpolarization in an SKCa/IKCa-dependent manner in the endothelium of old but not young mice. We conclude that the ability of resistance artery endothelium to release Ca2+ from intracellular stores (ie, ER and mitochondria) and hyperpolarize Vm via SKCa/IKCa activation is augmented as compensation for reduced NO bioavailability during advanced age.
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Affiliation(s)
- Erik J Behringer
- Department of Basic Sciences, Loma Linda University, California.,Department of Medical Pharmacology and Physiology, University of Missouri, Columbia
| | - Steven S Segal
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia.,Dalton Cardiovascular Research Center, Columbia, Missouri
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37
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Manicam C, Ginter N, Li H, Xia N, Goloborodko E, Zadeh JK, Musayeva A, Pfeiffer N, Gericke A. Compensatory Vasodilator Mechanisms in the Ophthalmic Artery of Endothelial Nitric Oxide Synthase Gene Knockout Mice. Sci Rep 2017; 7:7111. [PMID: 28769073 PMCID: PMC5541003 DOI: 10.1038/s41598-017-07768-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 06/29/2017] [Indexed: 01/02/2023] Open
Abstract
Nitric oxide (NO) generated by endothelial nitric oxide synthase (eNOS) plays an important role in the maintenance of ocular vascular homeostasis. Therefore, perturbations in vascular NO synthesis have been implicated in the pathogenesis of several ocular diseases. We recently reported that eNOS contributes significantly to vasodilation of the mouse ophthalmic artery. Interestingly, dilatory responses were also retained in eNOS gene-deficient mice (eNOS-/-), indicating inherent endothelial adaptive mechanism(s) that act as back-up systems in chronic absence of eNOS to preserve vasorelaxation. Thus, this study endeavoured to identify the compensatory mechanism(s) in the ophthalmic artery of eNOS-/- mice employing isolated arterial segments and pharmacological inhibitors in vitro. Endothelium removal virtually abolished acetylcholine (ACh)-induced vasodilation, suggesting an obligatory involvement of the endothelium in cholinergic control of vascular tone. However, non-NOS and non-cyclooxygenase components compensate for eNOS deficiency via endothelium-derived hyperpolarizing factors (EDHFs). Notably, arachidonic acid-derived metabolites of the 12-lipoxygenase pathway were key mediators in activating the inwardly rectifying potassium channels to compensate for chronic lack of eNOS. Conclusively, endothelium-dependent cholinergic responses of the ophthalmic artery in the eNOS-/- mice are largely preserved and, this vascular bed has the ability to compensate for the loss of normal vasodilator responses solely via EDHFs.
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Affiliation(s)
- Caroline Manicam
- Department of Ophthalmology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany.
| | - Natalja Ginter
- Department of Ophthalmology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Huige Li
- Institute of Pharmacology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Ning Xia
- Institute of Pharmacology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Evgeny Goloborodko
- Department of Ophthalmology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Jenia Kouchek Zadeh
- Department of Ophthalmology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Aytan Musayeva
- Department of Ophthalmology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Norbert Pfeiffer
- Department of Ophthalmology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Adrian Gericke
- Department of Ophthalmology, University Medical Centre of the Johannes Gutenberg University Mainz, Mainz, Germany
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de Sá FG, de Queiroz DB, Ramos-Alves FE, Santos-Rocha J, da Silva OA, Moreira HS, Leal GA, da Rocha MA, Duarte GP, Xavier FE. Hyperglycaemia in pregnant rats causes sex-related vascular dysfunction in adult offspring: role of cyclooxygenase-2. Exp Physiol 2017; 102:1019-1036. [PMID: 28556994 DOI: 10.1113/ep086132] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 05/23/2017] [Indexed: 12/12/2022]
Abstract
NEW FINDINGS What is the central question of this study? Hyperglycaemia during pregnancy induces vascular dysfunction and hypertension in male offspring. Given that female offspring from other fetal programming models are protected from the effects of fetal insult, the present study investigated whether there are sex differences in blood pressure and vascular function in hyperglycaemia-programmed offspring. What is the main finding and its importance? We demonstrated that hyperglycaemia in pregnant rats induced vascular dysfunction and hypertension only in male offspring. We found sex differences in oxidative stress and cyclooxygenase-2-derived prostanoid production that might underlie the vascular dysfunction. These differences, particularly in resistance arteries, may in part explain the absence of hypertension in female offspring born to hyperglycaemic dams. Exposure to maternal hyperglycaemia induces hypertension and vascular dysfunction in adult male offspring. Given that female offspring from several fetal programming models are protected from the effects of fetal insult, in this study we analysed possible differences relative to sex in blood pressure and vascular function in hyperglycaemia-programmed offspring. Hyperglycaemia was induced on day 7 of gestation (streptozotocin, 50 mg kg-1 ). Blood pressure, acetylcholine and phenylephrine or noradrenaline responses were analysed in the aorta and mesenteric resistance arteries of 3-, 6- and 12-month-old male and female offspring. Thromboxane A2 release was analysed with commercial kits and superoxide anion (O2- ) production by dihydroethidium-emitted fluorescence. Male but not female offspring of hyperglycaemic dams (O-DR) had higher blood pressure than control animals (O-CR). Contraction in response to phenylephrine increased and relaxation in response to acetylcholine decreased only in the aorta from 12-month-old male O-DR and not in age-matched O-CR. Contractile and vasodilator responses were preserved in both the aorta and mesenteric resistance arteries from female O-DR of all ages. Pre-incubation with tempol, superoxide dismutase, indomethacin, NS-398, furegrelate or SQ29548 decreased contraction in response to phenylephrine and potentiated relaxation in response to acetylcholine in 12-month-old male O-DR aorta. In this artery, thromboxane A2 release and O2- generation were greater in O-DR than O-CR groups. In conclusion, exposure to hyperglycaemia in utero results in sex-specific and age-dependent hypertension. The fact that vascular function is preserved in female O-DR may in part explain the absence of hypertension in this group. In contrast, the peripheral artery dysfunction associated with increased cyclooxygenase-2-derived production of vasoconstrictor prostanoids could underlie the increased blood pressure in male O-DR.
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Affiliation(s)
- Francine Gomes de Sá
- Departamento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, Recife, Brazil
| | | | | | - Juliana Santos-Rocha
- Departamento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, Recife, Brazil
| | - Odair Alves da Silva
- Departamento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, Recife, Brazil
| | - Hicla Stefany Moreira
- Departamento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, Recife, Brazil
| | - Geórgia Andrade Leal
- Departamento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, Recife, Brazil
| | | | - Gloria Pinto Duarte
- Departamento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, Recife, Brazil
| | - Fabiano Elias Xavier
- Departamento de Fisiologia e Farmacologia, Universidade Federal de Pernambuco, Recife, Brazil
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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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Tare M, Kalidindi RSR, Bubb KJ, Parkington HC, Boon WM, Li X, Sobey CG, Drummond GR, Ritchie RH, Kemp-Harper BK. Vasoactive actions of nitroxyl (HNO) are preserved in resistance arteries in diabetes. Naunyn Schmiedebergs Arch Pharmacol 2017; 390:397-408. [PMID: 28074232 DOI: 10.1007/s00210-016-1336-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Accepted: 12/27/2016] [Indexed: 10/20/2022]
Abstract
Endothelial dysfunction is a major risk factor for the vascular complications of diabetes. Increased reactive oxygen species (ROS) generation, a hallmark of diabetes, reduces the bioavailability of endothelial vasodilators, including nitric oxide (NO·). The vascular endothelium also produces the one electron reduced and protonated form of NO·, nitroxyl (HNO). Unlike NO·, HNO is resistant to scavenging by superoxide anions (·O2─). The fate of HNO in resistance arteries in diabetes is unknown. We tested the hypothesis that the vasodilator actions of endogenous and exogenous HNO are preserved in resistance arteries in diabetes. We investigated the actions of HNO in small arteries from the mesenteric and femoral beds as they exhibit marked differences in endothelial vasodilator function following 8 weeks of streptozotocin (STZ)-induced diabetes mellitus. Vascular reactivity was assessed using wire myography and ·O2─ generation using lucigenin-enhanced chemiluminescence. The HNO donor, Angeli's salt, and the NO· donor, DEA/NO, evoked relaxations in both arteries of control rats, and these responses were unaffected by diabetes. Nox2 oxidase expression and ·O2─ generation were upregulated in mesenteric, but unchanged, in femoral arteries of diabetic rats. Acetylcholine-induced endothelium-dependent relaxation was impaired in mesenteric but not femoral arteries in diabetes. The HNO scavenger, L-cysteine, reduced this endothelium-dependent relaxation to a similar extent in femoral and mesenteric arteries from control and diabetic animals. In conclusion, HNO and NO· contribute to the NO synthase (NOS)-sensitive component of endothelium-dependent relaxation in mesenteric and femoral arteries. The role of HNO is sustained in diabetes, serving to maintain endothelium-dependent relaxation.
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Affiliation(s)
- Marianne Tare
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, VIC, 3800, Australia.,Monash Rural Health, Monash University, Churchill, VIC, Australia
| | - Rushita S R Kalidindi
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Melbourne, VIC, 3800, Australia
| | - Kristen J Bubb
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, VIC, 3800, Australia.,Kolling Institute, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - Helena C Parkington
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, VIC, 3800, Australia
| | - Wee-Ming Boon
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, VIC, 3800, Australia
| | - Xiang Li
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Physiology, Monash University, Melbourne, VIC, 3800, Australia
| | - Christopher G Sobey
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Melbourne, VIC, 3800, Australia
| | - Grant R Drummond
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Melbourne, VIC, 3800, Australia
| | - Rebecca H Ritchie
- Baker IDI Heart and Diabetes Institute, Melbourne, VIC, Australia.,Department of Medicine, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Barbara K Kemp-Harper
- Cardiovascular Disease Program, Biomedicine Discovery Institute, Department of Pharmacology, Monash University, Melbourne, VIC, 3800, Australia.
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Serelaxin treatment reverses vascular dysfunction and left ventricular hypertrophy in a mouse model of Type 1 diabetes. Sci Rep 2017; 7:39604. [PMID: 28067255 PMCID: PMC5220363 DOI: 10.1038/srep39604] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 11/24/2016] [Indexed: 12/20/2022] Open
Abstract
Serelaxin prevents endothelial dysfunction in the mouse aorta ex vivo and inhibits apoptosis in cardiomyocytes under acute hyperglycaemia. Less is known about the effects of serelaxin in an in vivo mouse model of diabetes. Therefore, we tested the hypothesis in streptozotocin (STZ)-treated mice that serelaxin is able to reverse diabetes-induced vascular dysfunction and cardiac remodelling. Mice were divided into citrate buffer + placebo, STZ + placebo and STZ + serelaxin (0.5 mg/kg/d, 2 weeks) groups. After 12 weeks of diabetes, sensitivity to the endothelium-dependent agonist acetylcholine (ACh) was reduced in the mesenteric artery. This was accompanied by an enhanced vasoconstrictor prostanoid contribution and a decrease in endothelium-derived hyperpolarisation (EDH)-mediated relaxation. Serelaxin restored endothelial function by increasing nitric oxide (NO)-mediated relaxation but not EDH. It also normalised the contribution of vasoconstrictor prostanoids to endothelial dysfunction and suppressed diabetes-induced hyper-responsiveness of the mesenteric artery to angiotensin II. Similarly, diabetes reduced ACh-evoked NO-mediated relaxation in the aorta which was reversed by serelaxin. In the left ventricle, diabetes promoted apoptosis, hypertrophy and fibrosis; serelaxin treatment reversed this ventricular apoptosis and hypertrophy, but had no effect on fibrosis. In summary, serelaxin reversed diabetes-induced endothelial dysfunction by enhancing NO-mediated relaxation in the mouse vasculature and attenuating left ventricular hypertrophy and apoptosis.
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42
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Vanhoutte PM, Shimokawa H, Feletou M, Tang EHC. Endothelial dysfunction and vascular disease - a 30th anniversary update. Acta Physiol (Oxf) 2017; 219:22-96. [PMID: 26706498 DOI: 10.1111/apha.12646] [Citation(s) in RCA: 556] [Impact Index Per Article: 79.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 10/27/2015] [Accepted: 12/17/2015] [Indexed: 02/06/2023]
Abstract
The endothelium can evoke relaxations of the underlying vascular smooth muscle, by releasing vasodilator substances. The best-characterized endothelium-derived relaxing factor (EDRF) is nitric oxide (NO) which activates soluble guanylyl cyclase in the vascular smooth muscle cells, with the production of cyclic guanosine monophosphate (cGMP) initiating relaxation. The endothelial cells also evoke hyperpolarization of the cell membrane of vascular smooth muscle (endothelium-dependent hyperpolarizations, EDH-mediated responses). As regards the latter, hydrogen peroxide (H2 O2 ) now appears to play a dominant role. Endothelium-dependent relaxations involve both pertussis toxin-sensitive Gi (e.g. responses to α2 -adrenergic agonists, serotonin, and thrombin) and pertussis toxin-insensitive Gq (e.g. adenosine diphosphate and bradykinin) coupling proteins. New stimulators (e.g. insulin, adiponectin) of the release of EDRFs have emerged. In recent years, evidence has also accumulated, confirming that the release of NO by the endothelial cell can chronically be upregulated (e.g. by oestrogens, exercise and dietary factors) and downregulated (e.g. oxidative stress, smoking, pollution and oxidized low-density lipoproteins) and that it is reduced with ageing and in the course of vascular disease (e.g. diabetes and hypertension). Arteries covered with regenerated endothelium (e.g. following angioplasty) selectively lose the pertussis toxin-sensitive pathway for NO release which favours vasospasm, thrombosis, penetration of macrophages, cellular growth and the inflammatory reaction leading to atherosclerosis. In addition to the release of NO (and EDH, in particular those due to H2 O2 ), endothelial cells also can evoke contraction of the underlying vascular smooth muscle cells by releasing endothelium-derived contracting factors. Recent evidence confirms that most endothelium-dependent acute increases in contractile force are due to the formation of vasoconstrictor prostanoids (endoperoxides and prostacyclin) which activate TP receptors of the vascular smooth muscle cells and that prostacyclin plays a key role in such responses. Endothelium-dependent contractions are exacerbated when the production of nitric oxide is impaired (e.g. by oxidative stress, ageing, spontaneous hypertension and diabetes). They contribute to the blunting of endothelium-dependent vasodilatations in aged subjects and essential hypertensive and diabetic patients. In addition, recent data confirm that the release of endothelin-1 can contribute to endothelial dysfunction and that the peptide appears to be an important contributor to vascular dysfunction. Finally, it has become clear that nitric oxide itself, under certain conditions (e.g. hypoxia), can cause biased activation of soluble guanylyl cyclase leading to the production of cyclic inosine monophosphate (cIMP) rather than cGMP and hence causes contraction rather than relaxation of the underlying vascular smooth muscle.
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Affiliation(s)
- P. M. Vanhoutte
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy; Li Ka Shing Faculty of Medicine; The University of Hong Kong; Hong Kong City Hong Kong
| | - H. Shimokawa
- Department of Cardiovascular Medicine; Tohoku University; Sendai Japan
| | - M. Feletou
- Department of Cardiovascular Research; Institut de Recherches Servier; Suresnes France
| | - E. H. C. Tang
- State Key Laboratory of Pharmaceutical Biotechnology and Department of Pharmacology and Pharmacy; Li Ka Shing Faculty of Medicine; The University of Hong Kong; Hong Kong City Hong Kong
- School of Biomedical Sciences; Li Ka Shing Faculty of Medicine; The University of Hong Kong; Hong Kong City Hong Kong
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43
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Coleman HA, Tare M, Parkington HC. Nonlinear effects of potassium channel blockers on endothelium-dependent hyperpolarization. Acta Physiol (Oxf) 2017; 219:324-334. [PMID: 27639255 DOI: 10.1111/apha.12805] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 02/12/2016] [Accepted: 09/13/2016] [Indexed: 12/17/2022]
Abstract
In a number of published studies on endothelium-dependent hyperpolarization and relaxation, the results of the effects of K+ blockers have been difficult to interpret. When the effects of two blockers have been studied, often either blocker by itself had little effect, whereas the two blockers combined tended to abolish the responses. Explanations suggested in the literature include an unusual pharmacology of the K+ channels, and possible blocker binding interactions. In contrast, when we applied the same blockers to segments of small blood vessels under voltage clamp, the blockers reduced the endothelium-dependent K+ current in a linearly additive manner. Resolution of these contrasting results is important as endothelium-derived hyperpolarization (EDH) makes its greatest contribution to vasorelaxation in arterioles and small resistance arteries, where it can exert a significant role in tissue perfusion and blood pressure regulation. Furthermore, EDH is impaired in various diseases. Here, we consider why the voltage-clamp results differ from earlier free-running membrane potential and contractility studies. We fitted voltage-clamp-derived current-voltage relationships with mathematical functions and considered theoretically the effects of partial and total block of endothelium-derived K+ -currents on the membrane potential of small blood vessels. When the K+ -conductance was partially reduced, equivalent to applying a single blocker, the effect on EDH was small. Total block of the endothelium-dependent K+ conductance abolished the hyperpolarization, in agreement with various published studies. We conclude that nonlinear summation of the hyperpolarizing response evoked by endothelial stimulation can explain the variable effectiveness of individual K+ channel blockers on endothelium-dependent hyperpolarization and resulting relaxation.
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Affiliation(s)
- H. A. Coleman
- Department of Physiology; Biomedicine Discovery Institute; Cardiovascular Disease Program; Monash University; Clayton Vic. Australia
| | - M. Tare
- Department of Physiology; Biomedicine Discovery Institute; Cardiovascular Disease Program; Monash University; Clayton Vic. Australia
| | - H. C. Parkington
- Department of Physiology; Biomedicine Discovery Institute; Cardiovascular Disease Program; Monash University; Clayton Vic. Australia
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Toral M, Romero M, Pérez-Vizcaíno F, Duarte J, Jiménez R. Antihypertensive effects of peroxisome proliferator-activated receptor-β/δ activation. Am J Physiol Heart Circ Physiol 2016; 312:H189-H200. [PMID: 27881385 DOI: 10.1152/ajpheart.00155.2016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 09/12/2016] [Accepted: 11/21/2016] [Indexed: 01/16/2023]
Abstract
Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor superfamily of ligand-activated transcription factors, which is composed of three members encoded by distinct genes: PPARα, PPARβ/δ, and PPARγ. The biological actions of PPARα and PPARγ and their potential as a cardiovascular therapeutic target have been extensively reviewed, whereas the biological actions of PPARβ/δ and its effectiveness as a therapeutic target in the treatment of hypertension remain less investigated. Preclinical studies suggest that pharmacological PPARβ/δ activation induces antihypertensive effects in direct [spontaneously hypertensive rat (SHR), ANG II, and DOCA-salt] and indirect (dyslipemic and gestational) models of hypertension, associated with end-organ damage protection. This review summarizes mechanistic insights into the antihypertensive effects of PPARβ/δ activators, including molecular and functional mechanisms. Pharmacological PPARβ/δ activation induces genomic actions including the increase of regulators of G protein-coupled signaling (RGS), acute nongenomic vasodilator effects, as well as the ability to improve the endothelial dysfunction, reduce vascular inflammation, vasoconstrictor responses, and sympathetic outflow from central nervous system. Evidence from clinical trials is also examined. These preclinical and clinical outcomes of PPARβ/δ ligands may provide a basis for the development of therapies in combating hypertension.
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Affiliation(s)
- Marta Toral
- Department of Pharmacology, School of Pharmacy, University of Granada, Granada, Spain
| | - Miguel Romero
- Department of Pharmacology, School of Pharmacy, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria de Granada, ibs.GRANADA, Granada, Spain
| | - Francisco Pérez-Vizcaíno
- Department of Pharmacology, School of Medicine, University Complutense of Madrid, Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid. Spain; and.,Ciber Enfermedades Respiratorias (Ciberes). Madrid. Spain
| | - Juan Duarte
- Department of Pharmacology, School of Pharmacy, University of Granada, Granada, Spain.,Instituto de Investigación Biosanitaria de Granada, ibs.GRANADA, Granada, Spain
| | - Rosario Jiménez
- Department of Pharmacology, School of Pharmacy, University of Granada, Granada, Spain; .,Instituto de Investigación Biosanitaria de Granada, ibs.GRANADA, Granada, Spain
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Diabetic Microvascular Disease and Pulmonary Fibrosis: The Contribution of Platelets and Systemic Inflammation. Int J Mol Sci 2016; 17:ijms17111853. [PMID: 27834824 PMCID: PMC5133853 DOI: 10.3390/ijms17111853] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 10/24/2016] [Accepted: 11/01/2016] [Indexed: 12/29/2022] Open
Abstract
Diabetes is strongly associated with systemic inflammation and oxidative stress, but its effect on pulmonary vascular disease and lung function has often been disregarded. Several studies identified restrictive lung disease and fibrotic changes in diabetic patients and in animal models of diabetes. While microvascular dysfunction is a well-known complication of diabetes, the mechanisms leading to diabetes-induced lung injury have largely been disregarded. We described the potential involvement of diabetes-induced platelet-endothelial interactions in perpetuating vascular inflammation and oxidative injury leading to fibrotic changes in the lung. Changes in nitric oxide synthase (NOS) activation and decreased NO bioavailability in the diabetic lung increase platelet activation and vascular injury and may account for platelet hyperreactivity reported in diabetic patients. Additionally, the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway has been reported to mediate pancreatic islet damage, and is implicated in the onset of diabetes, inflammation and vascular injury. Many growth factors and diabetes-induced agonists act via the JAK/STAT pathway. Other studies reported the contribution of the JAK/STAT pathway to the regulation of the pulmonary fibrotic process but the role of this pathway in the development of diabetic lung fibrosis has not been considered. These observations may open new therapeutic perspectives for modulating multiple pathways to mitigate diabetes onset or its pulmonary consequences.
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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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Jia G, Durante W, Sowers JR. Endothelium-Derived Hyperpolarizing Factors: A Potential Therapeutic Target for Vascular Dysfunction in Obesity and Insulin Resistance. Diabetes 2016; 65:2118-20. [PMID: 27456617 PMCID: PMC4955984 DOI: 10.2337/dbi16-0026] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Guanghong Jia
- Diabetes and Cardiovascular Research Center, Columbia, MO Harry S. Truman Memorial Veterans Hospital, Columbia, MO
| | - William Durante
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO
| | - James R Sowers
- Diabetes and Cardiovascular Research Center, Columbia, MO Harry S. Truman Memorial Veterans Hospital, Columbia, MO Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO Dalton Cardiovascular Research Center, Columbia, MO
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