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Ghiarone T, Castorena-Gonzalez JA, Foote CA, Ramirez-Perez FI, Ferreira-Santos L, Cabral-Amador FJ, de la Torre R, Ganga RR, Wheeler AA, Manrique-Acevedo C, Padilla J, Martinez-Lemus LA. ADAM17 cleaves the insulin receptor ectodomain on endothelial cells and causes vascular insulin resistance. Am J Physiol Heart Circ Physiol 2022; 323:H688-H701. [PMID: 36018759 PMCID: PMC9512115 DOI: 10.1152/ajpheart.00039.2022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 08/10/2022] [Accepted: 08/10/2022] [Indexed: 11/22/2022]
Abstract
Inflammation and vascular insulin resistance are hallmarks of type 2 diabetes (T2D). However, several potential mechanisms causing abnormal endothelial insulin signaling in T2D need further investigation. Evidence indicates that the activity of ADAM17 (a disintegrin and metalloproteinase-17) and the presence of insulin receptor (IR) in plasma are increased in subjects with T2D. Accordingly, we hypothesized that in T2D, increased ADAM17 activity sheds the IR ectodomain from endothelial cells and impairs insulin-induced vasodilation. We used small visceral arteries isolated from a cross-sectional study of subjects with and without T2D undergoing bariatric surgery, human cultured endothelial cells, and recombinant proteins to test our hypothesis. Here, we demonstrate that arteries from subjects with T2D had increased ADAM17 expression, reduced presence of tissue inhibitor of metalloproteinase-3 (TIMP3), decreased extracellular IRα, and impaired insulin-induced vasodilation versus those from subjects without T2D. In vitro, active ADAM17 cleaved the ectodomain of the IRβ subunit. Endothelial cells with ADAM17 overexpression or exposed to the protein kinase-C activator, PMA, had increased ADAM17 activity, decreased IRα presence on the cell surface, and increased IR shedding. Moreover, pharmacological inhibition of ADAM17 with TAPI-0 rescued PMA-induced IR shedding and insulin-signaling impairments in endothelial cells and insulin-stimulated vasodilation in human arteries. In aggregate, our findings suggest that ADAM17-mediated shedding of IR from the endothelial surface impairs insulin-mediated vasodilation. Thus, we propose that inhibition of ADAM17 sheddase activity should be considered a strategy to restore vascular insulin sensitivity in T2D.NEW & NOTEWORTHY To our knowledge, this is the first study to investigate the involvement of ADAM17 in causing impaired insulin-induced vasodilation in T2D. We provide evidence that ADAM17 activity is increased in the vasculature of patients with T2D and support the notion that ADAM17-mediated shedding of endothelial IRα ectodomains is a novel mechanism causing vascular insulin resistance. Our results highlight that targeting ADAM17 activity may be a potential therapeutic strategy to correct vascular insulin resistance in T2D.
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Affiliation(s)
- Thaysa Ghiarone
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Jorge A Castorena-Gonzalez
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
- Department of Pharmacology, School of Medicine, Tulane University, New Orleans, Louisiana
| | - Christopher A Foote
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Francisco I Ramirez-Perez
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
- Department of Biomedical, Biological and Chemical Engineering, University of Missouri, Columbia, Missouri
| | | | | | | | - Rama R Ganga
- Department of Surgery, University of Missouri, Columbia, Missouri
| | - Andrew A Wheeler
- Department of Surgery, University of Missouri, Columbia, Missouri
| | - Camila Manrique-Acevedo
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Missouri, Columbia, Missouri
- Research Service, Harry S. Truman Memorial Veterans' Hospital, Columbia, Missouri
| | - Jaume Padilla
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
- Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, Missouri
| | - Luis A Martinez-Lemus
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
- Department of Biomedical, Biological and Chemical Engineering, University of Missouri, Columbia, Missouri
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Zelinskaya I, Kornushin O, Savochkina E, Dyachuk V, Vasyutina M, Galagudza M, Toropova Y. Vascular region-specific changes in arterial tone in rats with type 2 diabetes mellitus: Opposite responses of mesenteric and femoral arteries to acetylcholine and 5-hydroxytryptamine. Life Sci 2021; 286:120011. [PMID: 34606853 DOI: 10.1016/j.lfs.2021.120011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 09/23/2021] [Accepted: 09/28/2021] [Indexed: 11/30/2022]
Abstract
AIMS Type 2 diabetes mellitus (T2DM) ranks in the top 10 causes of mortality worldwide. The key factor of T2DM vascular complications is endothelial dysfunction. It is characterized by the vessels motor activity disruption and endothelium-derived factors imbalance. The blood vessels morphological and molecular heterogeneity greatly affects the changes occurring in T2DM. Therefore, we conducted a comparative study of vascular bed changes occurring in T2DM. MAIN METHODS Male Wistar rats were fed a high-fat diet for 20 weeks, followed by a single streptozotocin injection (20 mg/kg). T2DM was confirmed with an oral glucose tolerance test. KEY FINDINGS A dose-dependent contraction study showed an increase in third-order mesenteric arterioles response to serotonin but not to phenylephrine. These vessels also exhibited a decrease in acetylcholine-dependent relaxation and an increase in guanylate cyclase function. At the same time, the femoral arteries showed a tendency for increased acetylcholine-dependent relaxation. The blood plasma analysis revealed low bioavailable nitric oxide and high levels of endothelin-1 and ROS. SIGNIFICANCE This knowledge, in conjunction with the features of the T2DM course, can allow further targeted approaches development for the prevention and treatment of vascular complications occurring in the disease.
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Affiliation(s)
- Irina Zelinskaya
- Almazov National Medical Research Centre, Saint Petersburg, Russia
| | - Oleg Kornushin
- Almazov National Medical Research Centre, Saint Petersburg, Russia
| | | | | | - Marina Vasyutina
- Almazov National Medical Research Centre, Saint Petersburg, Russia
| | - Michael Galagudza
- Almazov National Medical Research Centre, Saint Petersburg, Russia; Pavlov First Saint Petersburg State Medical University, Saint Petersburg, Russia
| | - Yana Toropova
- Almazov National Medical Research Centre, Saint Petersburg, Russia.
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Schach C, Wester M, Leibl F, Redel A, Gruber M, Maier LS, Endemann D, Wagner S. Reduced store-operated Ca 2+ entry impairs mesenteric artery function in response to high external glucose in type 2 diabetic ZDF rats. Clin Exp Pharmacol Physiol 2020; 47:1145-1157. [PMID: 32147830 DOI: 10.1111/1440-1681.13300] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 02/15/2020] [Accepted: 03/05/2020] [Indexed: 11/28/2022]
Abstract
Diabetes is a major risk factor for cardiovascular disease, affecting both endothelial and smooth muscle cells. Store-operated Ca2+ channels (SOCCs) have been implicated in many diabetic complications. Vascular dysfunction is common in patients with diabetes, but the role of SOCCs in diabetic vasculopathy is still unclear. Our research aimed to investigate the effects of high glucose (HG) on store-operated Ca2+ entry (SOCE) in small arteries. Small mesenteric arteries from type 2 diabetic Zucker fatty rats (ZDF) versus their non-diabetic controls (Zucker lean, ZL) were examined in a pressurized myograph. Vascular smooth muscle cells (VSMC) were isolated and intracellular Ca2+ was measured (Fura 2-AM). A specific protocol to deplete intracellular Ca2+ stores and thereby open SOCCs, as well as pharmacological SOCE inhibitors (SKF-96365, BTP-2), were used to artificially activate and inhibit SOCE, respectively. High glucose (40 mmol/L) relaxed arteries in a SKF-sensitive manner. Diabetic arteries exhibited reduced HG-induced relaxation, as well as reduced contraction after Ca2+ replenishment. Further, the rise in intracellular Ca2+ on account of SOCE is diminished in diabetic versus non-diabetic VSMCs and was insensitive to HG in diabetic VSMCs. The expression of SOCC proteins was measured, detecting a downregulation of Orai1 in diabetes. In conclusion, diabetes leads to a reduction of SOCE and SOCE-induced contraction, which is unresponsive to HG-mediated inhibition. The reduced expression of Orai1 in diabetic arteries could account for the observed reduction in SOCE.
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Affiliation(s)
- Christian Schach
- Abteilung für Kardiologie, Klinik und Poliklinik für Innere Medizin II, Universitäres Herzzentrum Regensburg, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Michael Wester
- Abteilung für Kardiologie, Klinik und Poliklinik für Innere Medizin II, Universitäres Herzzentrum Regensburg, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Florian Leibl
- Abteilung für Kardiologie, Klinik und Poliklinik für Innere Medizin II, Universitäres Herzzentrum Regensburg, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Andreas Redel
- Klinik für Anästhesiologie, Universitäres Herzzentrum Regensburg, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Michael Gruber
- Klinik für Anästhesiologie, Universitäres Herzzentrum Regensburg, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Lars S Maier
- Abteilung für Kardiologie, Klinik und Poliklinik für Innere Medizin II, Universitäres Herzzentrum Regensburg, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Dierk Endemann
- Abteilung für Kardiologie, Klinik und Poliklinik für Innere Medizin II, Universitäres Herzzentrum Regensburg, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Stefan Wagner
- Abteilung für Kardiologie, Klinik und Poliklinik für Innere Medizin II, Universitäres Herzzentrum Regensburg, Universitätsklinikum Regensburg, Regensburg, Germany
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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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Vorn R, Yoo HY. Effects of high glucose with or without other metabolic substrates on alpha-adrenergic contractions in rat mesenteric and femoral arteries. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2016; 21:91-97. [PMID: 28066145 PMCID: PMC5214915 DOI: 10.4196/kjpp.2017.21.1.91] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Revised: 10/04/2016] [Accepted: 10/10/2016] [Indexed: 01/01/2023]
Abstract
Hyperglycemia is associated with an increased risk of cardiovascular diseases. It has been demonstrated that chronic exposure to high glucose impaired endothelial functions. However, specific effects of short-term exposure to high glucose on vascular reactivity are controversial. Moreover, the combined effects of other metabolic substrates such as free fatty acids (FFA) on vascular reactivity remain poorly understood. Here we investigate the effects of short-term exposure to high glucose with or without other metabolic substrates including FFAs termed “nutrition full” (NF) solution, on mesenteric (MA) and deep femoral arteries (DFA) of rats. Arterial ring segments were mounted in a double-wire myograph. Contraction in response to phenylephrine (PhE) was determined in control (5 mM) and high glucose (23 mM, HG) environments over a 30 min period. In both arteries, PhE-inducedvasocontraction was enhanced by pre-incubation of HG solution. A combined incubation with HG and palmitic acid (100 µM) induced similar sensitization of PhE-contractions in both arteries. In contrast, high K+-induced contractions were not affected by HG. Interestingly, pre-incubation with NF solution decreased PhE-induced contraction in MA but increased the contraction in DFA. In NF solution, the HG-induced facilitation of PhE-contraction was not observed in MA. Furthermore, the PhE-induced contraction of DFA was attenuated by HG in NF solution. Our results demonstrate that the sensitization of PhE-induced arterial contraction by HG is differentially affected by other metabolic substrates. The conversation of skeletal arterial contractility by HG in NF solution requires careful interpretation of the previous in vitro studies where only glucose is included in physiological salt solutions. Further studies are required to elucidate the mechanism underlying the inconsistent effect of NF solution on MA and DFA.
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Affiliation(s)
- Rany Vorn
- Chung-Ang University Red Cross College of Nursing, Seoul 06974, Korea.; Chung-Ang University Graduate School, Seoul 06974, Korea
| | - Hae Young Yoo
- Chung-Ang University Red Cross College of Nursing, Seoul 06974, Korea
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Abstract
We investigated the functional effects of glucagon-like peptide-1 [GLP-1(7-36)] and GLP-1(9-36) and the mechanism(s) playing a role in the effects of these agents in isolated small resistance arteries from control and diabetic rats. Cumulative concentrations of GLP-1(7-36) and GLP-1(9-36) produced concentration-dependent relaxations in endothelium-intact but not endothelium-denuded arteries that were significantly decreased in diabetic rats. GLP-1 receptor antagonist exendin(9-39) significantly inhibited responses to GLP-1 analogs. Nitric oxide/cyclic guanosine monophosphate pathway blockers, but not indomethacin, significantly decreased responses to GLP-1(7-36) or GLP-1(9-36) in control and diabetic rats. 4-Aminopyridine or glibenclamide incubation did not alter relaxations to GLP-1 analogs. GLP-1(7-36)- and GLP-1(9-36)-induced relaxations were blunted significantly and to similar extends by charybdotoxin and apamin combination in control and diabetic rats. Catalase did not affect, whereas superoxide dismutase (SOD) caused a significant increase in relaxations to GLP-1 analogs only in diabetic rats. We provided evidence about the relaxant effects of GLP-1(7-36) and GLP-1(9-36) in resistance arteries that were reduced in diabetic rats. Both calcium-activated potassium channels and endothelium played a major role in relaxations. Increment in certain reactive oxygen species and/or reduction in superoxide dismutase function might play a role in reduced relaxant responses of resistance arteries to GLP-1(7-36) and GLP-1(9-36) in diabetic rats.
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MOKHTAR SS, RASOOL AHG. Role of endothelium-dependent hyperpolarisation and prostacyclin in diabetes. Malays J Med Sci 2015; 22:8-17. [PMID: 26023290 PMCID: PMC4438087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 11/11/2014] [Indexed: 06/04/2023] Open
Abstract
The endothelium plays a crucial role in maintaining vascular homeostasis by producing several vasodilating factors, including nitric oxide (NO), prostacyclin (PGI2), and endothelium-dependent hyperpolarisation (EDH); however, the balance between endothelial relaxing and contracting factors is disrupted in disease states such as diabetes mellitus and hypertension. Most reported studies of endothelial dysfunction in diabetes focused on the actions of NO; however, there is accumulating evidence demonstrating that in addition to NO, PGI2 and EDH are likely to contribute to the vasodilatation of blood vessels. EDH plays an important role as a regulator of vascular tone and reactivity in resistance and conduit arteries of animal models and humans. PGI2 only plays a minimal role in endothelium-dependent vasodilatation but may serve as an important compensatory mechanism in conditions in which NO and EDH activities are decreased. Further studies are needed to determine the exact roles of EDH and PGI2 in the development of endothelial dysfunction and clinical vasculopathy in humans with type 1 and type 2 diabetes.
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Affiliation(s)
- Siti Safiah MOKHTAR
- Pharmacology Vascular Laboratory, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Malaysia
| | - Aida Hanum Ghulam RASOOL
- Pharmacology Vascular Laboratory, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Malaysia
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El Assar M, Angulo J, Rodríguez-Mañas L. Oxidative stress and vascular inflammation in aging. Free Radic Biol Med 2013; 65:380-401. [PMID: 23851032 DOI: 10.1016/j.freeradbiomed.2013.07.003] [Citation(s) in RCA: 412] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 06/28/2013] [Accepted: 07/02/2013] [Indexed: 12/13/2022]
Abstract
Vascular aging, a determinant factor for cardiovascular disease and health status in the elderly, is now viewed as a modifiable risk factor. Impaired endothelial vasodilation is a early hallmark of arterial aging that precedes the clinical manifestations of vascular dysfunction, the first step to cardiovascular disease and influencing vascular outcomes in the elderly. Accordingly, the preservation of endothelial function is thought to be an essential determinant of healthy aging. With special attention on the effects of aging on the endothelial function, this review is focused on the two main mechanisms of aging-related endothelial dysfunction: oxidative stress and inflammation. Aging vasculature generates an excess of the reactive oxygen species (ROS), superoxide and hydrogen peroxide, that compromise the vasodilatory activity of nitric oxide (NO) and facilitate the formation of the deleterious radical, peroxynitrite. Main sources of ROS are mitochondrial respiratory chain and NADPH oxidases, although NOS uncoupling could also account for ROS generation. In addition, reduced antioxidant response mediated by erythroid-2-related factor-2 (Nrf2) and downregulation of mitochondrial manganese superoxide dismutase (SOD2) contributes to the establishment of chronic oxidative stress in aged vessels. This is accompanied by a chronic low-grade inflammatory phenotype that participates in defective endothelial vasodilation. The redox-sensitive transcription factor, nuclear factor-κB (NF-κB), is upregulated in vascular cells from old subjects and drives a proinflammatory shift that feedbacks oxidative stress. This chronic NF-κB activation is contributed by increased angiotensin-II signaling and downregulated sirtuins and precludes adequate cellular response to acute ROS generation. Interventions targeted to recover endogenous antioxidant capacity and cellular stress response rather than exogenous antioxidants could reverse oxidative stress-inflammation vicious cycle in vascular aging. Lifestyle attitudes such as caloric restriction and exercise training appear as effective ways to overcome defective antioxidant response and inflammation, favoring successful vascular aging and decreasing the risk for cardiovascular disease.
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Affiliation(s)
- Mariam El Assar
- Fundación para la Investigación Biomédica, Hospital Universitario de Getafe, Getafe, Spain
| | - Javier Angulo
- Instituto Ramón y Cajal de Investigación Sanitaria, Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Leocadio Rodríguez-Mañas
- Fundación para la Investigación Biomédica, Hospital Universitario de Getafe, Getafe, Spain; Servicio de Geriatría, Hospital Universitario de Getafe, Getafe, Spain.
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Ruane-O’Hora T, Shortt CM, Edge D, Markos F, Noble MI. Intraluminal hyperglycaemia causes conduit and resistance artery dilatation and inhibits vascular autoregulation in the anaesthetised pig. Can J Physiol Pharmacol 2013; 91:1031-6. [DOI: 10.1139/cjpp-2013-0206] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of intraluminal hyperglycaemia was investigated in the iliac artery of 11 anaesthetised pigs. Following isolation of a test segment, hyperglycaemic blood (40 mmol·L–1) caused a significant dilatation of the artery of 167 ± 208 μm (mean ± SD; n = 6, P = 0.031). Dilatations were reduced by N(G)-nitro-l-arginine methyl esther (250 μg·mL–1) from 145 ± 199 to 38 ± 5 μm), but this was not statistically significant (n = 6, P = 0.18). Intra-arterial infusions of d-glucose (20–40 mmol·L–1·min–1), during graded constrictions, caused statistically significant increases in blood flow (n = 11, P = 0.0013). Vasodilatation was confirmed by measurements of the ratio of immediate pressure steps to flow steps (∂P/∂F) during the graded obstruction experiments, showing a decrease in instantaneous vascular resistance from a control of 0.62 ± 0.30 to 0.33 ± 0.34 mm Hg·mL–1·min–1 (n = 7, P = 0.016). Autoregulation was assessed from the slopes of the plots of steady-state flow versus pressure. There were significant increases in the slope from 2.32 ± 1.03 to 5.88 ± 5.60 mL·min–1·(mm Hg)–1 (n = 7, P = 0.0078), indicating significant impairment of autoregulation. In conclusion, luminal hyperglycaemia relaxes both arterial and resistance vessel smooth muscle.
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Affiliation(s)
| | | | - Deirdre Edge
- Department of Physiology, University College Cork, Cork, Ireland
| | - Farouk Markos
- Department of Physiology, University College Cork, Cork, Ireland
| | - Mark I.M. Noble
- Cardiovascular Medicine, University of Aberdeen, Scotland, UK
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Assessment of leptomeningeal collaterals using dynamic CT angiography in patients with acute ischemic stroke. J Cereb Blood Flow Metab 2013; 33:365-71. [PMID: 23149554 PMCID: PMC3587807 DOI: 10.1038/jcbfm.2012.171] [Citation(s) in RCA: 129] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Whole-brain dynamic time-resolved computed tomography angiography (CTA) is a technique developed on the new 320-detector row CT scanner capable of generating time-resolved cerebral angiograms from skull base to vertex. Unlike a conventional cerebral angiogram, this technique visualizes pial arterial filling in all vascular territories, thereby providing additional hemodynamic information. Ours was a retrospective study of consecutive patients with ischemic stroke and M1 middle cerebral artery +/- intracranial internal carotid artery occlusions presenting to our center from June 2010 and undergoing dynamic time-resolved CTA and perfusion CT within 6 hours of symptom onset. Leptomeningeal collateral status was assessed by determining relative prominence of pial arteries in the ischemic region, rate and extent of retrograde flow, and various topographical patterns of pial arterial filling. Twenty-five patients were included in the study. We demonstrate the existence of the following novel properties of leptomeningeal collaterals in humans: (a) posterior (posterior cerebral artery (PCA)-MCA) dominant collateralization, (b) intra-territorial 'within MCA region' leptomeningeal collaterals, and (c) significant variability in size, extent, and retrograde filling time in pial arteries. We also describe a simple and reliable collateral grading template that, for the first time on dynamic CTA, incorporates back-filling time as well as size and extent of collateral filling.
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Rivilla F, Vallejo S, Peiró C, Sánchez-Ferrer CF. Characterization of endothelium-dependent relaxations in the mesenteric vasculature: a comparative study with potential pathophysiological relevance. J Pediatr Surg 2012; 47:2044-9. [PMID: 23163996 DOI: 10.1016/j.jpedsurg.2012.05.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 05/15/2012] [Accepted: 05/22/2012] [Indexed: 11/28/2022]
Abstract
BACKGROUND Endothelium-dependent relaxations in human adult mesenteric microvessels involve 3 different main mechanisms: cyclooxygenase (COX)-derived prostanoids, nitric oxide (NO), and endothelium-derived hyperpolarizing factor (EDHF), which elicits vascular smooth muscle hyperpolarization and relaxation. There are some pathological conditions with an abnormal balance between mesenteric vasoconstriction and vasodilatation inputs leading to endothelial dysfunction and tissue injury. PURPOSE The purpose was to characterize the mechanisms mediating endothelium-dependent relaxation and differences in children and adult mesenteric microvessels. METHODS Microvessels were dissected from omentum obtained from children (3-6 years old) and adults (25-41 years old) and mounted as ring preparations in a small vessel myograph. RESULTS In microvessels precontracted with a thromboxane analogue, the endothelium-dependent relaxations to bradykinin (10 nmol/L to 30 μmol/L) mediated by EDHF, that is, nonsensitive to COX (10 μmol/L indomethacin) and NO synthase blockade (100 μmol/L N-nitro-L-arginine methyl ester), were higher in children than in adults. When EDHF was blunted by a depolarizing precontraction with KCl, the remaining COX- and NO-dependent relaxations were significantly lower in children. CONCLUSIONS The EDHF's role in the endothelium-dependent relaxations is higher in children's vasculature. This suggests that endothelial dysfunction in mesenteric microvessels in children is likely more dependent on EDHF-related mechanisms rather than on NO- or COX-derived prostanoids.
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Affiliation(s)
- Fernando Rivilla
- Division of Pediatric Surgery, San Carlos University Hospital, Madrid 28040, Spain.
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Pathophysiology of diabetic erectile dysfunction: potential contribution of vasa nervorum and advanced glycation endproducts. Int J Impot Res 2012; 25:1-6. [PMID: 22914567 DOI: 10.1038/ijir.2012.30] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Erectile dysfunction (ED) due to diabetes mellitus remains difficult to treat medically despite advances in pharmacotherapeutic approaches in the field. This unmet need has resulted in a recent re-focus on the pathophysiology, in order to understand the cellular and molecular mechanisms leading to ED in diabetes. Diabetes-induced ED is often resistant to PDE5 inhibitor treatment, thus there is a need to discover targets that may lead to novel approaches for a successful treatment. The aim of this brief review is to update the reader in some of the latest development on that front, with a particular focus on the role of impaired neuronal blood flow and the formation of advanced glycation endproducts.
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13
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El Assar M, Angulo J, Vallejo S, Peiró C, Sánchez-Ferrer CF, Rodríguez-Mañas L. Mechanisms involved in the aging-induced vascular dysfunction. Front Physiol 2012; 3:132. [PMID: 22783194 PMCID: PMC3361078 DOI: 10.3389/fphys.2012.00132] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 04/20/2012] [Indexed: 12/25/2022] Open
Abstract
Vascular aging is a key process determining health status of aged population. Aging is an independent cardiovascular risk factor associated to an impairment of endothelial function, which is a very early and important event leading to cardiovascular disease. Vascular aging, formerly being considered an immutable and inexorable risk factor, is now viewed as a target process for intervention in order to achieve a healthier old age. A further knowledge of the mechanisms underlying the age-related vascular dysfunction is required to design an adequate therapeutic strategy to prevent or restore this impairment of vascular functionality. Among the proposed mechanisms that contribute to age-dependent endothelial dysfunction, this review is focused on the following aspects occurring into the vascular wall: (1) the reduction of nitric oxide (NO) bioavailability, caused by diminished NO synthesis and/or by augmented NO scavenging due to oxidative stress, leading to peroxynitrite formation (ONOO(-)); (2) the possible sources involved in the enhancement of oxidative stress; (3) the increased activity of vasoconstrictor factors; and (4) the development of a low-grade pro-inflammatory environment. Synergisms and interactions between all these pathways are also analyzed. Finally, a brief summary of some cellular mechanisms related to endothelial cell senescence (including telomere and telomerase, stress-induced senescence, as well as sirtuins) are implemented, as they are likely involved in the age-dependent endothelial dysfunction, as well as in the lower vascular repairing capacity observed in the elderly. Prevention or reversion of those mechanisms leading to endothelial dysfunction through life style modifications or pharmacological interventions could markedly improve cardiovascular health in older people.
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Affiliation(s)
- Mariam El Assar
- Fundación para la Investigación Biomédica, Hospital Universitario de Getafe Madrid, Spain
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Deshpande DD, Janero DR, Amiji MM. Therapeutic strategies for endothelial dysfunction. Expert Opin Biol Ther 2011; 11:1637-54. [DOI: 10.1517/14712598.2011.625007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Zhong MF, Shen WL, Wang J, Yang J, Yuan WJ, He J, Wu PP, Wang Y, Zhang L, Higashino H, Chen H. Paradoxical effects of streptozotocin-induced diabetes on endothelial dysfunction in stroke-prone spontaneously hypertensive rats. J Physiol 2011; 589:5153-65. [PMID: 21930604 PMCID: PMC3225671 DOI: 10.1113/jphysiol.2011.213686] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Non-technical summary Elevated blood glucose is generally regarded as one of the risk factors that lead to coronary heart disease in patients with type 2 diabetes. However, our studies show that after inducing short-term damage, high blood glucose subsequently provides paradoxical protection for vessel function of animals with high blood pressure. Vessels can adapt to sustained high blood glucose and produce different stress proteins to counteract, to some extent, the damage brought about by hypertension. The results help us understand part of the basis for vessel adaptation in diabetes. The implication for treatment of diabetes is that if the patients have long-standing diabetes and established cardiovascular disease, the target of blood glucose lowering should be less stringent and reached gradually to avoid abrupt cancellation of the pre-existing adaptations. Abstract Although both diabetes and hypertension are risk factors for cardiovascular disease, the role of hyperglycaemia per se in endothelial dysfunction is controversial. This study was designed to examine whether hyperglycaemia, or streptozotocin-induced diabetes, could aggravate endothelial dysfunction in stroke-prone spontaneously hypertensive rats (SHRSP). Hyperglycaemia was induced by streptozotocin in 2-month-old SHRSP and age-matched normotensive Wistar–Kyoto (WKY) rats. The aorta was isolated 8 weeks after induction of hyperglycaemia to record its function and to examine its morphology with transmission electron microscopy. Endothelial/inducible nitric oxide synthase (eNOS/iNOS) and inducible/constitutive haem oxygenase (HO-1/HO-2) levels were determined with Western blotting. Aortic endothelial function and production of reactive oxygen species and nitric oxide were assayed after incubation in vitro in hyperglycaemic, hyperosmolar solution. Streptozotocin-induced diabetes of 8 weeks duration did not result in endothelial dysfunction in normotensive WKY rats. In contrast, hyperglycaemic WKY rats showed significantly enhanced endothelium-dependent vasodilatation, which was abrogated by simultaneous blocking of NOS and HO. The enhanced vasodilatation was associated with elevation of vascular eNOS and HO-1. Significant endothelial dysfunction and massive macrophage–monocyte infiltration were found in SHRSP aorta (the ratio of the number of macrophages to endothelial cells in the intima, expressed as a percentage, was 20.9 ± 2.8% in SHRSP versus 1.9 ± 0.5% in WKY rats, P < 0.01), which was attenuated significantly in hyperglycaemic SHRSP (11.3 ± 1.6%, P < 0.01 versus SHRSP). Acute hyperglycaemia (10 min) aggravated endothelial dysfunction in SHRSP, with a marked increase in intracellular reactive oxygen species and NO production. Sustained in vitro incubation in hyperglycaemic/hyperosmolar conditions (addition of an extra 50 mmol L−1 of glucose or mannitol to the usual buffer, to produce a final osmolarity of 350 mosmol L−1) for 5 h enhanced endothelium-dependent vasodilatation, with elevated vessel NO production and upregulation of eNOS/HO-1 proteins. Sustained hyperglycaemia does not aggravate endothelial dysfunction and macrophage infiltration in SHRSP. Hyperglycaemia/hyperosmolarity-induced upregulation of eNOS and HO-1 may play a role in this paradoxical adaptation of endothelial function.
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Affiliation(s)
- Mei-Fang Zhong
- Department of Pharmacology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
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Ding H, Triggle CR. Endothelial dysfunction in diabetes: multiple targets for treatment. Pflugers Arch 2010; 459:977-94. [PMID: 20238124 DOI: 10.1007/s00424-010-0807-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 02/13/2010] [Accepted: 02/16/2010] [Indexed: 12/20/2022]
Abstract
Robert Furchgott's discovery of the obligatory role that the endothelium plays in the regulation of vascular tone has proved to be a major advance in terms of our understanding of the cellular basis of diabetic vascular disease. Endothelial dysfunction, as defined by a reduction in the vasodilatation response to an endothelium-dependent vasodilator (such as acetylcholine) or to flow-mediated vasodilatation, is an early indicator for the development of the micro- and macroangipathy that is associated with diabetes. In diabetes, hyperglycaemia plays a key role in the initiation and development of endothelial dysfunction; however, the cellular mechanisms involved as well as the importance of dyslipidaemia and co-morbidities such as hypertension and obesity remain incompletely understood. In this review, we discuss the mechanisms whereby hyperglycaemia, oxidative stress and dyslipidaemia can alter endothelial function and highlight their effects on endothelial nitric oxide synthase (eNOS), the endothelium-dependent hyperpolarising factor (EDHF) pathway(s), as well as on the role of endothelium-derived contracting factors (EDCFs) and adipocyte-derived vasoactive factors such as adipose-derived relaxing factor (ADRF).
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Affiliation(s)
- Hong Ding
- Department of Pharmacology & Medical Education, Weill Cornell Medical College in Qatar, P.O. Box 24144, Education City, Doha, Qatar
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Rodríguez-Mañas L, El-Assar M, Vallejo S, López-Dóriga P, Solís J, Petidier R, Montes M, Nevado J, Castro M, Gómez-Guerrero C, Peiró C, Sánchez-Ferrer CF. Endothelial dysfunction in aged humans is related with oxidative stress and vascular inflammation. Aging Cell 2009; 8:226-38. [PMID: 19245678 DOI: 10.1111/j.1474-9726.2009.00466.x] [Citation(s) in RCA: 157] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Vascular endothelial dysfunction occurs during the human aging process, and it is considered as a crucial event in the development of many vasculopathies. We investigated the underlying mechanisms of this process, particularly those related with oxidative stress and inflammation, in the vasculature of subjects aged 18-91 years without cardiovascular disease or risk factors. In isolated mesenteric microvessels from these subjects, an age-dependent impairment of the endothelium-dependent relaxations to bradykinin was observed. Similar results were observed by plethysmography in the forearm blood flow in response to acetylcholine. In microvessels from subjects aged less than 60 years, most of the bradykinin-induced relaxation was due to nitric oxide release while the rest was sensitive to cyclooxygenase (COX) blockade. In microvessels from subjects older than 60 years, this COX-derived vasodilatation was lost but a COX-derived vasoconstriction occurred. Evidence for age-related vascular oxidant and inflammatory environment was observed, which could be related to the development of endothelial dysfunction. Indeed, aged microvessels showed superoxide anions (O(2)(-)) and peroxynitrite (ONOO(-)) formation, enhancement of NADPH oxidase and inducible NO synthase expression. Pharmacological interference of COX, thromboxane A(2)/prostaglandin H(2) receptor, O(2)(-), ONOO(-), inducible NO synthase, and NADPH oxidase improved the age-related endothelial dysfunction. In situ vascular nuclear factor-kappaB activation was enhanced with age, which correlated with endothelial dysfunction. We conclude that the age-dependent endothelial dysfunction in human vessels is due to the combined effect of oxidative stress and vascular wall inflammation.
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Su Y, Liu XM, Sun YM, Jin HB, Luan Y, Wu Y. Na+/Ca2+EXCHANGER INHIBITOR AMELIORATES IMPAIRED ENDOTHELIUM-DEPENDENT Na+RELAXATION INDUCED BY HIGH GLUCOSE IN RAT AORTA. Clin Exp Pharmacol Physiol 2008; 35:1265-70. [DOI: 10.1111/j.1440-1681.2008.05002.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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