1
|
Hall LG, Czeczor JK, Connor T, Botella J, De Jong KA, Renton MC, Genders AJ, Venardos K, Martin SD, Bond ST, Aston-Mourney K, Howlett KF, Campbell JA, Collier GR, Walder KR, McKenzie M, Ziemann M, McGee SL. Amyloid beta 42 alters cardiac metabolism and impairs cardiac function in male mice with obesity. Nat Commun 2024; 15:258. [PMID: 38225272 PMCID: PMC10789867 DOI: 10.1038/s41467-023-44520-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 12/15/2023] [Indexed: 01/17/2024] Open
Abstract
There are epidemiological associations between obesity and type 2 diabetes, cardiovascular disease and Alzheimer's disease. The role of amyloid beta 42 (Aβ42) in these diverse chronic diseases is obscure. Here we show that adipose tissue releases Aβ42, which is increased from adipose tissue of male mice with obesity and is associated with higher plasma Aβ42. Increasing circulating Aβ42 levels in male mice without obesity has no effect on systemic glucose homeostasis but has obesity-like effects on the heart, including reduced cardiac glucose clearance and impaired cardiac function. The closely related Aβ40 isoform does not have these same effects on the heart. Administration of an Aβ-neutralising antibody prevents obesity-induced cardiac dysfunction and hypertrophy. Furthermore, Aβ-neutralising antibody administration in established obesity prevents further deterioration of cardiac function. Multi-contrast transcriptomic analyses reveal that Aβ42 impacts pathways of mitochondrial metabolism and exposure of cardiomyocytes to Aβ42 inhibits mitochondrial complex I. These data reveal a role for systemic Aβ42 in the development of cardiac disease in obesity and suggest that therapeutics designed for Alzheimer's disease could be effective in combating obesity-induced heart failure.
Collapse
Affiliation(s)
- Liam G Hall
- Institute for Mental and Physical Health and Clinical Translation, Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
- Department of Cellular and Physiological Sciences, Faculty of Medicine, The University of British Columbia, Vancouver, Canada
| | - Juliane K Czeczor
- Institute for Mental and Physical Health and Clinical Translation, Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
- Becton Dickinson GmbH, Medical Affairs, 69126, Heidelberg, Germany
| | - Timothy Connor
- Institute for Mental and Physical Health and Clinical Translation, Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
| | - Javier Botella
- Institute for Mental and Physical Health and Clinical Translation, Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
| | - Kirstie A De Jong
- Institute for Mental and Physical Health and Clinical Translation, Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
- Institute of Experimental Cardiovascular Research, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Mark C Renton
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | - Amanda J Genders
- Institute for Mental and Physical Health and Clinical Translation, Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
- Department of Nutrition, Dietetics and Food, School of Clinical Sciences and Victorian Heart Institute, Monash University, Melbourne, Australia
| | - Kylie Venardos
- Institute for Mental and Physical Health and Clinical Translation, Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
| | - Sheree D Martin
- Institute for Mental and Physical Health and Clinical Translation, Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
| | - Simon T Bond
- Institute for Mental and Physical Health and Clinical Translation, Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
- Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Kathryn Aston-Mourney
- Institute for Mental and Physical Health and Clinical Translation, Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
| | - Kirsten F Howlett
- Institute for Physical Activity and Nutrition, School of Exercise and Nutrition Sciences, Deakin University, Geelong, Australia
| | | | | | - Ken R Walder
- Institute for Mental and Physical Health and Clinical Translation, Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
| | - Matthew McKenzie
- School of Life and Environmental Science, Deakin University, Geelong, Australia
| | - Mark Ziemann
- School of Life and Environmental Science, Deakin University, Geelong, Australia
| | - Sean L McGee
- Institute for Mental and Physical Health and Clinical Translation, Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia.
- Ambetex Pty Ltd, Geelong, Australia.
| |
Collapse
|
2
|
Gaur V, Connor T, Venardos K, Henstridge DC, Martin SD, Swinton C, Morrison S, Aston-Mourney K, Gehrig SM, van Ewijk R, Lynch GS, Febbraio MA, Steinberg GR, Hargreaves M, Walder KR, McGee SL. Scriptaid enhances skeletal muscle insulin action and cardiac function in obese mice. Diabetes Obes Metab 2017; 19:936-943. [PMID: 28155245 DOI: 10.1111/dom.12896] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 01/26/2017] [Accepted: 01/28/2017] [Indexed: 12/20/2022]
Abstract
AIM To determine the effect of Scriptaid, a compound that can replicate aspects of the exercise adaptive response through disruption of the class IIa histone deacetylase (HDAC) corepressor complex, on muscle insulin action in obesity. MATERIALS AND METHODS Diet-induced obese mice were administered Scriptaid (1 mg/kg) via daily intraperitoneal injection for 4 weeks. Whole-body and skeletal muscle metabolic phenotyping of mice was performed, in addition to echocardiography, to assess cardiac morphology and function. RESULTS Scriptaid treatment had no effect on body weight or composition, but did increase energy expenditure, supported by increased lipid oxidation, while food intake was also increased. Scriptaid enhanced the expression of oxidative genes and proteins, increased fatty acid oxidation and reduced triglycerides and diacylglycerides in skeletal muscle. Furthermore, ex vivo insulin-stimulated glucose uptake by skeletal muscle was enhanced. Surprisingly, heart weight was reduced in Scriptaid-treated mice and was associated with enhanced expression of genes involved in oxidative metabolism in the heart. Scriptaid also improved indices of both diastolic and systolic cardiac function. CONCLUSION These data show that pharmacological targeting of the class IIa HDAC corepressor complex with Scriptaid could be used to enhance muscle insulin action and cardiac function in obesity.
Collapse
Affiliation(s)
- Vidhi Gaur
- Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
| | - Timothy Connor
- Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
| | - Kylie Venardos
- Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
| | - Darren C Henstridge
- Metabolism and Inflammation Program, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Sheree D Martin
- Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
| | - Courtney Swinton
- Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
| | - Shona Morrison
- Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
| | | | - Stefan M Gehrig
- Department of Physiology, The University of Melbourne, Parkville, Australia
| | - Roelof van Ewijk
- Department of Physiology, The University of Melbourne, Parkville, Australia
| | - Gordon S Lynch
- Department of Physiology, The University of Melbourne, Parkville, Australia
| | - Mark A Febbraio
- Metabolism and Inflammation Program, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
- Division of Diabetes and Metabolism, Garvan Institute of Medical Research, Darlinghurst, Australia
| | - Gregory R Steinberg
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Canada
| | - Mark Hargreaves
- Department of Physiology, The University of Melbourne, Parkville, Australia
| | - Ken R Walder
- Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
| | - Sean L McGee
- Metabolic Research Unit, School of Medicine, Deakin University, Geelong, Australia
- Metabolism and Inflammation Program, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| |
Collapse
|
3
|
McQuilten ZK, Bailey M, Cameron PA, Stanworth SJ, Venardos K, Wood EM, Cooper DJ. Fibrinogen concentration and use of fibrinogen supplementation with cryoprecipitate in patients with critical bleeding receiving massive transfusion: a bi-national cohort study. Br J Haematol 2017; 179:131-141. [PMID: 28653339 DOI: 10.1111/bjh.14804] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 05/01/2017] [Indexed: 02/06/2023]
Abstract
We aimed to compare hypofibrinogenaemia prevalence in major bleeding patients across all clinical contexts, fibrinogen supplementation practice, and explore the relationship between fibrinogen concentrations and mortality. This cohort study included all adult patients from 20 hospitals across Australia and New Zealand who received massive transfusion between April 2011 and October 2015. Of 3566 patients, 2829 (79%) had fibrinogen concentration recorded, with a median first and lowest concentration of 2·0 g/l (interquartile range [IQR] 1·5-2·7) and 1·8 g/l (IQR 1·3-2·4), respectively. Liver transplant (1·7 g/l, IQR 1·2-2·1), trauma (1·8, IQR 1·3-2·5) and vascular surgery (1·9 g/l, IQR 1·4-2·5) had lower concentrations. Total median fibrinogen dose administered from all products was 7·3 g (IQR 3·3-13·0). Overall, 1732 (61%) received cryoprecipitate and 9 (<1%) fibrinogen concentrate. Time to cryoprecipitate issue in those with initial fibrinogen concentration <1 g/l was 2·5 h (IQR 1·2-4·3 h). After adjustment, initial fibrinogen concentration had a U-shaped association with in-hospital mortality [adjusted odds ratios: fibrinogen <1 g/l, 2·31 (95% confidence interval (CI) 1·48-3·60); 1-1·9 g/l, 1·29 (95% CI 0·99-1·67) and >4 g/l, 2·03 (95% CI 1·35-3·04), 2-4 g/l reference category]. The findings indicate areas for practice improvement including timely administration of cryoprecipitate, which is the most common source of concentrated fibrinogen in Australia and New Zealand.
Collapse
Affiliation(s)
- Zoe K McQuilten
- Australian and New Zealand Intensive Care Research Centre (ANZIC-RC), Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.,Transfusion Research Unit, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.,Monash Health, Melbourne, Australia
| | - Michael Bailey
- Australian and New Zealand Intensive Care Research Centre (ANZIC-RC), Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
| | - Peter A Cameron
- Transfusion Research Unit, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
| | - Simon J Stanworth
- NHS Blood and Transplant/Oxford University Hospitals NHS Trust, John Radcliffe Hospital, and Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Kylie Venardos
- Transfusion Research Unit, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
| | - Erica M Wood
- Transfusion Research Unit, Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia.,Monash Health, Melbourne, Australia
| | - D James Cooper
- Australian and New Zealand Intensive Care Research Centre (ANZIC-RC), Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia
| |
Collapse
|
4
|
Venardos K, De Jong KA, Elkamie M, Connor T, McGee SL. The PKD inhibitor CID755673 enhances cardiac function in diabetic db/db mice. PLoS One 2015; 10:e0120934. [PMID: 25798941 PMCID: PMC4370864 DOI: 10.1371/journal.pone.0120934] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 02/09/2015] [Indexed: 01/06/2023] Open
Abstract
The development of diabetic cardiomyopathy is a key contributor to heart failure and mortality in obesity and type 2 diabetes (T2D). Current therapeutic interventions for T2D have limited impact on the development of diabetic cardiomyopathy. Clearly, new therapies are urgently needed. A potential therapeutic target is protein kinase D (PKD), which is activated by metabolic insults and implicated in the regulation of cardiac metabolism, contractility and hypertrophy. We therefore hypothesised that PKD inhibition would enhance cardiac function in T2D mice. We first validated the obese and T2D db/db mouse as a model of early stage diabetic cardiomyopathy, which was characterised by both diastolic and systolic dysfunction, without overt alterations in left ventricular morphology. These functional characteristics were also associated with increased PKD2 phosphorylation in the fed state and a gene expression signature characteristic of PKD activation. Acute administration of the PKD inhibitor CID755673 to normal mice reduced both PKD1 and 2 phosphorylation in a time and dose-dependent manner. Chronic CID755673 administration to T2D db/db mice for two weeks reduced expression of the gene expression signature of PKD activation, enhanced indices of both diastolic and systolic left ventricular function and was associated with reduced heart weight. These alterations in cardiac function were independent of changes in glucose homeostasis, insulin action and body composition. These findings suggest that PKD inhibition could be an effective strategy to enhance heart function in obese and diabetic patients and provide an impetus for further mechanistic investigations into the role of PKD in diabetic cardiomyopathy.
Collapse
Affiliation(s)
- Kylie Venardos
- Metabolic Remodelling Laboratory, Metabolic Research Unit, School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
| | - Kirstie A. De Jong
- Metabolic Remodelling Laboratory, Metabolic Research Unit, School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
| | - Mansour Elkamie
- Metabolic Remodelling Laboratory, Metabolic Research Unit, School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
| | - Timothy Connor
- Metabolic Remodelling Laboratory, Metabolic Research Unit, School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
| | - Sean L. McGee
- Metabolic Remodelling Laboratory, Metabolic Research Unit, School of Medicine, Deakin University, Waurn Ponds, Victoria, Australia
- Program for Metabolism and Inflammation, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia
- * E-mail:
| |
Collapse
|
5
|
De Jong K, McGee S, Venardos K, Connor T, Elkamie M. The PKD inhibitor CID755673 enhances heart function in diabetic db/db mice. Heart Lung Circ 2015. [DOI: 10.1016/j.hlc.2015.06.187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
6
|
Chen Y, Rothnie C, Spring D, Verrier E, Venardos K, Kaye D, Phillips DJ, Hedger MP, Smith JA. Regulation and actions of activin A and follistatin in myocardial ischaemia-reperfusion injury. Cytokine 2014; 69:255-62. [PMID: 25052838 DOI: 10.1016/j.cyto.2014.06.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Revised: 04/13/2014] [Accepted: 06/23/2014] [Indexed: 12/14/2022]
Abstract
Activin A, a member of the transforming growth factor-β superfamily, is stimulated early in inflammation via the Toll-like receptor (TLR) 4 signalling pathway, which is also activated in myocardial ischaemia-reperfusion. Neutralising activin A by treatment with the activin-binding protein, follistatin, reduces inflammation and mortality in several disease models. This study assesses the regulation of activin A and follistatin in a murine myocardial ischaemia-reperfusion model and determines whether exogenous follistatin treatment is protective against injury. Myocardial activin A and follistatin protein levels were elevated following 30 min of ischaemia and 2h of reperfusion in wild-type mice. Activin A, but not follistatin, gene expression was also up-regulated. Serum activin A did not change significantly, but serum follistatin decreased. These responses to ischaemia-reperfusion were absent in TLR4(-/-) mice. Pre-treatment with follistatin significantly reduced ischaemia-reperfusion induced myocardial infarction. In mouse neonatal cardiomyocyte cultures, activin A exacerbated, while follistatin reduced, cellular injury after 3h of hypoxia and 2h of re-oxygenation. Neither activin A nor follistatin affected hypoxia-reoxygenation induced reactive oxygen species production by these cells. However, activin A reduced cardiomyocyte mitochondrial membrane potential, and follistatin treatment ameliorated the effect of hypoxia-reoxygenation on cardiomyocyte mitochondrial membrane potential. Taken together, these data indicate that myocardial ischaemia-reperfusion, through activation of TLR4 signalling, stimulates local production of activin A, which damages cardiomyocytes independently of increased reactive oxygen species. Blocking activin action by exogenous follistatin reduces this damage.
Collapse
Affiliation(s)
- Yi Chen
- Department of Surgery, Monash Medical Centre, Monash University, Clayton, Victoria 3168, Australia; MIMR-PHI Institute of Medical Research, Monash Medical Centre, Clayton, Victoria 3168, Australia.
| | - Christine Rothnie
- Department of Surgery, School of Medicine, University of Washington, Seattle, WA 98195-6410, USA
| | - Denise Spring
- Department of Surgery, School of Medicine, University of Washington, Seattle, WA 98195-6410, USA
| | - Edward Verrier
- Department of Surgery, School of Medicine, University of Washington, Seattle, WA 98195-6410, USA
| | - Kylie Venardos
- Heart Failure Research Group, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia
| | - David Kaye
- Heart Failure Research Group, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria 3004, Australia
| | - David J Phillips
- MIMR-PHI Institute of Medical Research, Monash Medical Centre, Clayton, Victoria 3168, Australia; Epworth Research Institute, Epworth HealthCare, Richmond, Victoria 3121, Australia
| | - Mark P Hedger
- MIMR-PHI Institute of Medical Research, Monash Medical Centre, Clayton, Victoria 3168, Australia
| | - Julian A Smith
- Department of Surgery, Monash Medical Centre, Monash University, Clayton, Victoria 3168, Australia
| |
Collapse
|
7
|
Konstantinidis G, Head GA, Evans RG, Nguyen-Huu TP, Venardos K, Croft KD, Mori TA, Kaye DM, Rajapakse NW. Endothelial cationic amino acid transporter-1 overexpression can prevent oxidative stress and increases in arterial pressure in response to superoxide dismutase inhibition in mice. Acta Physiol (Oxf) 2014; 210:845-53. [PMID: 24428817 DOI: 10.1111/apha.12215] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/30/2013] [Accepted: 12/11/2013] [Indexed: 12/28/2022]
Abstract
AIM Oxidative stress may play an important role in the pathogenesis of hypertension. The aim of our study is to examine whether increased expression of the predominant endothelial l-arginine transporter, cationic amino acid transporter-1 (CAT1), can prevent oxidative stress-induced hypertension. METHODS Wild-type mice (WT; n = 9) and endothelial CAT1 overexpressing (CAT+) mice (n = 6) had telemetry probes implanted for the measurement of mean arterial pressure (MAP), heart rate (HR) and locomotor activity. Minipumps were implanted for infusion of the superoxide dismutase inhibitor diethyldithiocarbamic acid (DETCA; 30 mg kg(-1) day(-1) ; 14 days) or its saline vehicle. Baseline levels of MAP, HR and locomotor activity were determined before and during chronic DETCA administration. Mice were then killed, and their plasma and kidneys collected for analysis of F2 -isoprostane levels. RESULTS Basal MAP was less in CAT+ (92 ± 2 mmHg; n = 6) than in WT (98 ± 2 mmHg; n = 9; P < 0.001). During DETCA infusion, MAP was increased in WT (by 4.2 ± 0.5%; P < 0.001) but not in CAT+, when compared to appropriate controls (PDETCA*genotype = 0.006). DETCA infusion increased total plasma F2 -isoprostane levels (by 67 ± 11%; P = 0.05) in WT but not in CAT+. Total renal F2 -isoprostane levels were greater during DETCA infusion in WT (by 72%; P < 0.001), but not in CAT+, compared to appropriate controls. CONCLUSION Augmented endothelial l-arginine transport attenuated the prohypertensive effects of systemic and renal oxidative stress, suggesting that manipulation of endothelial CAT1 may provide a new therapeutic approach for the treatment of cardiovascular disease associated with oxidative stress.
Collapse
Affiliation(s)
- G. Konstantinidis
- Baker IDI Heart and Diabetes Institute; Melbourne Vic. Australia
- Department of Physiology; Monash University; Melbourne Vic. Australia
| | - G. A. Head
- Baker IDI Heart and Diabetes Institute; Melbourne Vic. Australia
| | - R. G. Evans
- Department of Physiology; Monash University; Melbourne Vic. Australia
| | - T.-P. Nguyen-Huu
- Baker IDI Heart and Diabetes Institute; Melbourne Vic. Australia
| | - K. Venardos
- Baker IDI Heart and Diabetes Institute; Melbourne Vic. Australia
| | - K. D. Croft
- School of Medicine and Pharmacology; Royal Perth Hospital Unit; University of Western Australia; Perth WA Australia
| | - T. A. Mori
- School of Medicine and Pharmacology; Royal Perth Hospital Unit; University of Western Australia; Perth WA Australia
| | - D. M. Kaye
- Baker IDI Heart and Diabetes Institute; Melbourne Vic. Australia
| | - N. W. Rajapakse
- Baker IDI Heart and Diabetes Institute; Melbourne Vic. Australia
- Department of Physiology; Monash University; Melbourne Vic. Australia
| |
Collapse
|
8
|
Qin C, Buxton KD, Pepe S, Cao AH, Venardos K, Love JE, Kaye DM, Yang YH, Morand EF, Ritchie RH. Reperfusion-induced myocardial dysfunction is prevented by endogenous annexin-A1 and its N-terminal-derived peptide Ac-ANX-A1(2-26). Br J Pharmacol 2014; 168:238-52. [PMID: 22924634 DOI: 10.1111/j.1476-5381.2012.02176.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 07/19/2012] [Accepted: 07/26/2012] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND AND PURPOSE Annexin-A1 (ANX-A1) is an endogenous, glucocorticoid-regulated anti-inflammatory protein. The N-terminal-derived peptide Ac-ANX-A1(2-26) preserves cardiomyocyte viability, but the impact of ANX-A1-peptides on cardiac contractility is unknown. We now test the hypothesis that ANX-A1 preserves post-ischaemic recovery of left ventricular (LV) function. EXPERIMENTAL APPROACH Ac-ANX-A1(2-26) was administered on reperfusion, to adult rat cardiomyocytes as well as hearts isolated from rats, wild-type mice and mice deficient in endogenous ANX-A1 (ANX-A1(-/-)). Myocardial viability and recovery of LV function were determined. KEY RESULTS Ischaemia-reperfusion markedly impaired both cardiomyocyte viability and recovery of LV function by 60%. Treatment with exogenous Ac-ANX-A1(2-26) at the onset of reperfusion prevented cardiomyocyte injury and significantly improved recovery of LV function, in both intact rat and wild-type mouse hearts. Ac-ANX-A1(2-26) cardioprotection was abolished by either formyl peptide receptor (FPR)-nonselective or FPR1-selective antagonists, Boc2 and cyclosporin H, but was relatively insensitive to the FPR2-selective antagonist QuinC7. ANX-A1-induced cardioprotection was associated with increased phosphorylation of the cell survival kinase Akt. ANX-A1(-/-) exaggerated impairment of post-ischaemic recovery of LV function, in addition to selective LV FPR1 down-regulation. CONCLUSIONS AND IMPLICATIONS These data represent the first evidence that ANX-A1 affects myocardial function. Our findings suggest ANX-A1 is an endogenous regulator of post-ischaemic recovery of LV function. Furthermore, the ANX-A1-derived peptide Ac-ANX-A1(2-26) on reperfusion rescues LV function, probably via activation of FPR1. ANX-A1-based therapies may thus represent a novel clinical approach for the prevention and treatment of myocardial reperfusion injury.
Collapse
Affiliation(s)
- Chengxue Qin
- Baker IDI Heart & Diabetes Institute, Melbourne, Australia
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Khong SML, Andrews KL, Huynh NN, Venardos K, Aprico A, Michell DL, Zarei M, Moe KT, Dusting GJ, Kaye DM, Chin-Dusting JPF. Arginase II inhibition prevents nitrate tolerance. Br J Pharmacol 2012; 166:2015-23. [PMID: 22288373 DOI: 10.1111/j.1476-5381.2012.01876.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND AND PURPOSE Nitrate tolerance, the loss of vascular responsiveness with continued use of nitrates, remains incompletely understood and is a limitation of these therapeutic agents. Vascular superoxide, generated by uncoupled endothelial NOS (eNOS), may play a role. As arginase competes with eNOS for L-arginine and may exacerbate the production of reactive oxygen species (ROS), we hypothesized that arginase inhibition might reduce nitrate tolerance. EXPERIMENTAL APPROACH Vasodilator responses were measured in aorta from C57Bl/6 and arginase II knockout (argII -/-) mice using myography. Uncoupling of eNOS, determined as eNOS monomer : dimer ratio, was assessed using low-temperature SDS-PAGE and ROS levels were measured using L-012 and lucigenin-enhanced chemiluminescence. KEY RESULTS Repeated application of glyceryl trinitrate (GTN) on aorta isolated from C57Bl/6 mice produced a 32-fold rightward shift of the concentration-response curve. However this rightward shift (or resultant tolerance) was not observed in the presence of the arginase inhibitor (s)-(2-boronethyl)-L-cysteine HCl (BEC; 100 µM) nor in aorta isolated from argII -/- mice. Similar findings were obtained after inducing nitrate tolerance in vivo. Repeated administration of GTN in human umbilical vein endothelial cells induced uncoupling of eNOS from its dimeric state and increased ROS levels, which were reduced with arginase inhibition and exogenous L-arginine. Aortae from GTN tolerant C57Bl/6 mice exhibited increased arginase activity and ROS production, whereas vessels from argII -/- mice did not. CONCLUSION AND IMPLICATIONS Arginase II removal prevents nitrate tolerance. This may be due to decreased uncoupling of eNOS and consequent ROS production.
Collapse
Affiliation(s)
- S M L Khong
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Rajapakse NW, Kuruppu S, Hanchapola I, Venardos K, Mattson DL, Smith AI, Kaye DM, Evans RG. Evidence that renal arginine transport is impaired in spontaneously hypertensive rats. Am J Physiol Renal Physiol 2012; 302:F1554-62. [DOI: 10.1152/ajprenal.00084.2011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Low renal nitric oxide (NO) bioavailability contributes to the development and maintenance of chronic hypertension. We investigated whether impaired l-arginine transport contributes to low renal NO bioavailability in hypertension. Responses of renal medullary perfusion and NO concentration to renal arterial infusions of the l-arginine transport inhibitor l-lysine (10 μmol·kg−1·min−1; 30 min) and subsequent superimposition of l-arginine (100 μmol·kg−1·min−1; 30 min), the NO synthase inhibitor NG-nitro-l-arginine (2.4 mg/kg; iv bolus), and the NO donor sodium nitroprusside (0.24 μg·kg−1·min−1) were examined in Sprague-Dawley rats (SD) and spontaneously hypertensive rats (SHR). Renal medullary perfusion and NO concentration were measured by laser-Doppler flowmetry and polarographically, respectively, 5.5 mm below the kidney surface. Renal medullary NO concentration was less in SHR (53 ± 3 nM) compared with SD rats (108 ± 12 nM; P = 0.004). l-Lysine tended to reduce medullary perfusion (−15 ± 7%; P = 0.07) and reduced medullary NO concentration (−9 ± 3%; P = 0.03) while subsequent superimposition of l-arginine reversed these effects of l-lysine in SD rats. In SHR, l-lysine and subsequent superimposition of l-arginine did not significantly alter medullary perfusion or NO concentration. Collectively, these data suggest that renal l-arginine transport is impaired in SHR. Renal l-[3H]arginine transport was less in SHR compared with SD rats ( P = 0.01). Accordingly, we conclude that impaired arginine transport contributes to low renal NO bioavailability observed in the SHR kidney.
Collapse
Affiliation(s)
- N. W. Rajapakse
- Department of Physiology, Monash University,
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia; and
| | - S. Kuruppu
- Department of Biochemistry and Molecular Biology, Monash University, and
| | - I. Hanchapola
- Department of Biochemistry and Molecular Biology, Monash University, and
| | - K. Venardos
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia; and
| | - D. L. Mattson
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - A. I. Smith
- Department of Biochemistry and Molecular Biology, Monash University, and
| | - D. M. Kaye
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia; and
| | - R. G. Evans
- Department of Physiology, Monash University,
| |
Collapse
|
11
|
Qin C, Buxton K, Pepe S, Cao A, Venardos K, Love J, Kaye D, Yang Y, Morand E, Ritchie R. Role of FPR1 Formyl Peptide Receptors in the Cardioprotective Actions of Annexin-A1 Against Ischaemia–Reperfusion (I–R) Injury. Heart Lung Circ 2012. [DOI: 10.1016/j.hlc.2012.05.233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
12
|
Venardos K, Williams D, Peart J, Kaye D. Cardioprotective Effects of Combined l-Arginine and Insulin: Mechanism and Therapeutic Actions in Myocardial Ischemia–Reperfusion Injury. Heart Lung Circ 2012. [DOI: 10.1016/j.hlc.2012.05.141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
13
|
Ritchie RH, Buxton K, Pepe S, Cao AH, Venardos K, Love J, Yang Y, Morand E, Kaye D. Abstract P285: Impaired Recovery of Left Ventricular Function After Acute Myocardial Reperfusion Injury Is Rescued by the Anti-inflammatory Peptide Annexin-A1 ex Vivo. Circ Res 2011. [DOI: 10.1161/res.109.suppl_1.ap285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The glucocorticoid-regulated protein annexin-A1 (ANX-A1) is a key effector molecule of anti-inflammatory glucocorticoid actions. We have shown that the N-terminal derived peptide ANX-A1(2–26) preserves cardiomyocyte viability after metabolic inhibition in vitro. Our hypothesis was that ANX-A1 preserves the myocardium post-ischemic injury. ANX-A1(2–26)(0.3μM) prevented adult rat cardiomyocyte injury, whether present for hypoxia-reoxygenation (LDH release reduced from 4.1±0.7- to 1.1±0.2-fold n=11 P<0.001) or only on reoxygenation (LDH release reduced to 1.4±0.4-fold n=11, P<0.001). Similar protection at both time points was also evident on cardiomyocyte viability (trypan blue exclusion). The recovery of post-ischemic left ventricular (LV) function in intact rodent hearts was also protected. After 20mins reperfusion, the recovery of LV developed pressure (LVDP) remained significantly impaired in untreated rat hearts (47±5% baseline, n=11) whereas addition of ANX-A1(2–26)(0.3μM) on reperfusion improved LVDP recovery (to 66±7% baseline, n=13, p<0.05). Phosphorylation of both Akt (1.9±0.2-fold, P<0.05) and phospholamban (3.4±0.4-fold, P<0.05) was also enhanced by ANX-A1(2–26). Similar ANX-A1(2–26)-induced rescue of LV function was observed in mouse hearts after acute myocardial reperfusion injury (57±7% of baseline, n=11 untreated hearts vs 78±8% baseline, n=6 ANX-A1(2–26)-treated hearts, p<0.05). ANX-A1(2–26) cardioprotection was associated with attenuated cardiac enzyme release (LDH, CK) and Akt phosphorylation (3.1±0.8-fold, P<0.005). In contrast, deficiency of endogenous ANX-A1 further exacerbated recovery of post-ischemic LV function, across LVDP (to 29±4% baseline, P<0.001), LV end-diastolic pressure (to 5.5±1.0-fold baseline, P<0.001), LV+dP/dt (to 33±4% baseline, P<0.001), LV-dP/dt (to 36±4% baseline, P<0.001) and rate-pressure product (to 24±4% baseline, P<0.001). This is the first evidence that ANX-A1 or its mimetic ANX-A1(2-26) preserve post-ischemic recovery of LV function. ANX-A1 is thus an endogenous regulator of LV function. Furthermore, ANX-A1-based therapies may thus represent a novel clinical approach for the prevention and treatment of reperfusion injury.
Collapse
Affiliation(s)
| | - Keith Buxton
- Baker IDI Heart&Diabetes Inst, Melbourne, Australia
| | - Salvatore Pepe
- The Univ of Melbourne and Murdoch Childrens Rsch Institute, Melbourne, Australia
| | - Anh H Cao
- Baker IDI Heart&Diabetes Inst, Melbourne, Australia
| | | | - Jane Love
- Baker IDI Heart&Diabetes Inst, Melbourne, Australia
| | | | | | - David Kaye
- Baker IDI Heart&Diabetes Inst, Melbourne, Australia
| |
Collapse
|
14
|
Ritchie R, Buxton K, Pepe S, Cao A, Venardos K, Love J, Yang Y, Morand E, Kaye D. Impaired Recovery of Left Ventricular (LV) Function after Acute Myocardial Reperfusion Injury is Rescued by the Anti-inflammatory Peptide Annexin-A1 (ANX-A1) Ex Vivo. Heart Lung Circ 2011. [DOI: 10.1016/j.hlc.2011.05.168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
15
|
Ritchie R, Khammy M, Bowden M, Irvine J, Andrews K, Huynh K, Kiriazis H, Kaye D, Venardos K. Diabetes-Induced Cardiac Dysfunction is Rescued by Endothelial Cationic Amino Acid Transporter 1 (CAT-1) Overexpression in Mice. Heart Lung Circ 2011. [DOI: 10.1016/j.hlc.2011.05.159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
16
|
Soro-Paavonen A, Zhang WZ, Venardos K, Coughlan MT, Harris E, Tong DCK, Brasacchio D, Paavonen K, Chin-Dusting J, Cooper ME, Kaye D, Thomas MC, Forbes JM. Advanced glycation end-products induce vascular dysfunction via resistance to nitric oxide and suppression of endothelial nitric oxide synthase. J Hypertens 2010; 28:780-8. [PMID: 20186099 DOI: 10.1097/hjh.0b013e328335043e] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE A number of factors contribute to diabetes-associated vascular dysfunction. In the present study, we tested whether exposure to advanced glycation end-products (AGEs) impairs vascular reactivity independently of hyperglycemia and examined the potential mechanisms responsible for diabetes and AGE-associated vascular dysfunction. METHODS Vasodilator function was studied using infusion of exogenous AGEs into Sprague-Dawley rats as compared with control and streptozotocin-induced diabetic rats all followed for 16 weeks (n = 10 per group). The level of arginine metabolites and expression of endothelial nitric oxide synthase (eNOS) and downstream mediators of nitric oxide-dependent signaling were examined. To further explore these mechanisms, cultured bovine aortic endothelial cells (BAECs) were exposed to AGEs. RESULTS Both diabetic and animals infused with AGE-modified rat serum albumin (AGE-RSA) had significantly impaired vasodilatory response to acetylcholine. Unlike diabetes-associated endothelial dysfunction, AGE infusion was not associated with changes in plasma arginine metabolites, asymmetric dimethyl-L-arginine levels or eNOS expression. However, expression of the downstream mediator cGMP-dependent protein kinase 1 (PKG-1) was significantly reduced by both AGE exposure and diabetes. AGEs also augmented hyperglycemia-associated depletion in endothelial nitric oxide production and eNOS protein expression in vitro, and the novel AGE inhibitor, alagebrium chloride, partly restored these parameters. CONCLUSION We demonstrate that AGEs represent a potentially important cause of vascular dysfunction, linked to the induction of nitric oxide resistance. These findings also emphasize the deleterious and potentially additive effects of AGEs and hyperglycemia in diabetic vasculature.
Collapse
|
17
|
Venardos K, Williams D, Yang Z, Byrne M, Kaye D. Reduced Mitochondrial l-Arginine Transport Contributes to the Pathogenesis of Heart Failure. Heart Lung Circ 2010. [DOI: 10.1016/j.hlc.2010.06.774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
18
|
Venardos K, Zhang WZ, Lang C, Kaye DM. Effect of peroxynitrite on endothelial L-arginine transport and metabolism. Int J Biochem Cell Biol 2009; 41:2522-7. [PMID: 19695340 DOI: 10.1016/j.biocel.2009.08.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2009] [Revised: 07/29/2009] [Accepted: 08/11/2009] [Indexed: 02/07/2023]
Abstract
Under conditions of oxidative stress it is well known that the bioavailability of nitric oxide (NO) is known to be significantly reduced. This process is in part due to the combination of NO with superoxide radicals to form peroxynitrite (ONOO(-)). While this process inactivates NO per se, it is not certain to which extent this process may also further impair ongoing NO production. Given the pivotal role of arginine availability for NO synthesis we determined the impact of ONOO(-) on endothelial arginine transport and intracellular arginine metabolism. Peroxynitrite reduced endothelial [(3)H]-L-arginine transport and increased the rate of arginine efflux in a concentration-dependent manner (both p<0.05). In conjunction, exposure to ONOO(-) significantly reduced the intracellular concentration of L-arginine, N(G)-hydroxy-L-arginine (an intermediate of NO biosynthesis) and citrulline by 46%, 45% and 60% respectively (all p<0.05), while asymmetric dimethyl arginine (ADMA) levels rose by 180% (p<0.05). ONOO(-) exposure did not alter the cellular distribution of the principal L-arginine transporter, CAT1, rather the effect on CAT1 activity appeared to be mediated by protein nitrosation. Conclusion Peroxynitrite negatively influences NO production by combined effects on arginine uptake and efflux, most likely due to a nitrosative action of ONOO(-) on CAT-1.
Collapse
Affiliation(s)
- Kylie Venardos
- Heart Failure Research Group, Baker IDI Heart & Diabetes Institute, PO Box 6492 St Kilda Rd Central, Melbourne, VIC, Australia
| | | | | | | |
Collapse
|
19
|
Venardos K, Enriquez C, Marshall T, Chin-Dusting JPF, Ahlers B, Kaye DM. Protein kinase C mediated inhibition of endothelial L-arginine transport is mediated by MARCKS protein. J Mol Cell Cardiol 2008; 46:86-92. [PMID: 18977358 DOI: 10.1016/j.yjmcc.2008.09.712] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Revised: 09/04/2008] [Accepted: 09/19/2008] [Indexed: 11/19/2022]
Abstract
The endothelium plays a vital role in the maintenance of vascular tone and structural vascular integrity, principally mediated via the actions of nitric oxide (NO). L-arginine is the immediate substrate for NO synthesis, and the availability of extracellular L-arginine is critical for the production of NO. Activation of protein kinase C (PKC) dependent signalling pathways are a feature of a number of cardiovascular disease states, and in this study we aimed to systematically evaluate the mechanism by which PKC regulates L-arginine transport in endothelial cells. In response to PKC activation (PMA 100 nM, 30 min), [(3)H]L-arginine uptake by bovine aortic endothelial cells (BAEC) was reduced to 45+4% of control (p<0.05). This resulted from a 53% reduction in the Vmax (p<0.05), with no change in the K(m) for L-arginine. Western blot analysis and confocal microscopy revealed no change in the expression or membrane distribution of CAT-1, the principal BAEC L-arginine transporter. Moreover in (32)P-labeling studies, PMA exposure did not result in CAT-1 phosphorylation. We therefore explored the possibility that PKC altered and interaction with MARCKS protein, a candidate membrane associated protein. By co-immunoprecipitation we show that CAT-1 interacts with, a membrane associated protein, that was significantly inhibited by PKC activation (p<0.05). Moreover antisense inhibition of MARCKS abolished the PMA effect on L-arginine transport. PKC dependent mechanisms regulate the transport of L-arginine, mediated via process involving MARCKS.
Collapse
Affiliation(s)
- Kylie Venardos
- Heart Failure Research Group, Baker Heart Research Institute, Melbourne VIC, Australia
| | | | | | | | | | | |
Collapse
|
20
|
Zhang WZ, Venardos K, Finch S, Kaye DM. Detrimental effect of oxidized LDL on endothelial arginine metabolism and transportation. Int J Biochem Cell Biol 2008; 40:920-8. [DOI: 10.1016/j.biocel.2007.10.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Revised: 10/15/2007] [Accepted: 10/22/2007] [Indexed: 10/22/2022]
|
21
|
Venardos K, Williams D, Kaye D. Mitochondrial l-Arginine (l-Arg) Transport and the Failing Heart. Heart Lung Circ 2008. [DOI: 10.1016/j.hlc.2008.05.569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
22
|
Venardos K, Willems L, Kaye DM. Cardioprotective actions of upregulated l-arginine (l-Arg) transport. J Mol Cell Cardiol 2007. [DOI: 10.1016/j.yjmcc.2007.03.598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
23
|
Yang Z, Venardos K, Jones E, Morris BJ, Chin-Dusting J, Kaye DM. Identification of a novel polymorphism in the 3'UTR of the L-arginine transporter gene SLC7A1: contribution to hypertension and endothelial dysfunction. Circulation 2007; 115:1269-74. [PMID: 17325243 DOI: 10.1161/circulationaha.106.665836] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Endothelial dysfunction because of reduced nitric oxide bioavailability is a key feature of essential hypertension. We have found that normotensive siblings of subjects with essential hypertension have impaired endothelial function accompanied by altered arginine metabolism. METHODS AND RESULTS We have identified a novel C/T polymorphism in the 3'UTR of the principal arginine transporter, solute carrier family 7 (cationic amino acid transporter, y+ system), member 1 gene (SLC7A1). The minor T allele significantly attenuates reporter gene expression (P<0.01) and is impaired in its capacity to form DNA-protein complexes (P<0.05). In 278 hypertensive subjects the frequency of the T allele was 13.3% compared with 7.6% in 498 normotensive subjects (P<0.001). Moreover, the overall genotype distribution observed in hypertensives differed significantly from that in normotensives (P<0.001). To complement these studies, we generated an endothelial-specific transgenic mouse overexpressing L-arginine transporter SLC7A1. The Slc7A1 transgenic mice exhibited significantly enhanced responses to the endothelium-dependent vasodilator acetylcholine (-log EC50 for wild-type versus Slc7A1 transgenic: 6.87+/-0.10 versus 7.56+/-0.13; P<0.001). This was accompanied by elevated production of nitric oxide by isolated aortic endothelial cells. CONCLUSIONS The present study identifies a key, functionally active polymorphism in the 3'UTR of SLC7A1. As such, this polymorphism may account for the apparent link between altered endothelial function, L-arginine, and nitric oxide metabolism and predisposition to essential hypertension.
Collapse
Affiliation(s)
- Zhiyong Yang
- Wynn Department of Metabolic Cardiology, Baker Heart Research Institute, PO Box 6492, St Kilda Rd Central, Melbourne, VIC 8008, Australia
| | | | | | | | | | | |
Collapse
|
24
|
Zhang WZ, Venardos K, Chin-Dusting J, Kaye DM. Response to Cigarettes and ADMA: The Smoke Hasn’t Cleared Yet. Hypertension 2006. [DOI: 10.1161/01.hyp.0000239812.05676.1d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Wei-Zheng Zhang
- Wynn Department of Metabolic Cardiology, Baker Heart Research Institute, Melbourne, Australia
| | - Kylie Venardos
- Wynn Department of Metabolic Cardiology, Baker Heart Research Institute, Melbourne, Australia
| | - Jaye Chin-Dusting
- Vascular Pharmacology, Baker Heart Research Institute, Melbourne, Australia
| | - David M. Kaye
- Wynn Department of Metabolic Cardiology, Baker Heart Research Institute, Melbourne, Australia
| |
Collapse
|
25
|
Venardos K, Zhang WZ, Chin-Dusting J, M Kaye D. Cigarette smoke adversely influences nitric oxide bioavailability by effects on L-arginine transport and oxidative stress in endothelial cells. J Mol Cell Cardiol 2006. [DOI: 10.1016/j.yjmcc.2006.06.057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
26
|
Abstract
Endothelial dysfunction is a hallmark of cardiovascular disease, and the l-arginine:NO pathway plays a critical role in determining endothelial function. Recent studies suggest that smoking, a well-recognized risk factor for vascular disease, may interfere with l-arginine and NO metabolism; however, this remains poorly characterized. Accordingly, we performed a series of complementary in vivo and in vitro studies to elucidate the mechanism by which cigarette smoke adversely affects endothelial function. In current smokers, plasma levels of asymmetrical dimethyl-arginine (ADMA) were 80% higher (P = 0.01) than nonsmokers, whereas citrulline (17%; P < 0.05) and N-hydroxy-l-arginine (34%; P < 0.05) were significantly lower. Exposure to 10% cigarette smoke extract (CSE) significantly affected endothelial arginine metabolism with reductions in the intracellular content of citrulline (81%), N-hydroxy-l-arginine (57%), and arginine (23%), while increasing ADMA (129%). CSE significantly inhibited (38%) arginine uptake in conjunction with a 34% reduction in expression of the arginine transporter, CAT1. In conjunction with these studies, CSE significantly reduced the activity of eNOS and NO production by endothelial cells, while stimulating the production of reactive oxygen species. In conclusion, cigarette smoke adversely affects the endothelial l-arginine NO synthase pathway, resulting in reducing NO production and elevated oxidative stress. In conjunction, exposure to cigarette smoke increases ADMA concentration, the latter being a risk factor for cardiovascular disease.
Collapse
Affiliation(s)
- Wei-Zheng Zhang
- Wynn Department of Metabolic Cardiology, Baker Heart Research Institute, PO Box 6492, St Kilda Rd Central, Melbourne, Victoria 8008, Australia
| | | | | | | |
Collapse
|
27
|
Lymbury R, Venardos K, Perkins AV. Effect of sodium selenite-enriched reperfusion solutions on rat cardiac ischemia reperfusion injury. Biol Trace Elem Res 2006; 114:197-206. [PMID: 17206002 DOI: 10.1385/bter:114:1:197] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Revised: 01/10/2006] [Accepted: 02/10/2006] [Indexed: 11/11/2022]
Abstract
Cardiac surgery often generates oxidative stress leading to ischemia reperfusion injury (I-R). Antioxidants have been shown to prevent this injury and have been added to cardioplegic solutions to assist in recovery. In this study, we tested the effectiveness of sodium selenite in protecting against ischemia reperfusion injury and investigated the mechanisms behind this protection. Hearts from male Wistar rats were subjected to ischemia reperfusion using the Langendorf model. Krebs-Henseleit perfusion solutions were supplemented with 0, 0.1, 0.5, 1.0, and 10 microM sodium selenite. Hearts were perfused for 30 min and then subjected to 22.5 min of global ischemia followed by 45 min reperfusion. Heart rate, ischemic contracture, end diastolic pressure, and developed ventricular pressure were monitored. At the completion of the experiment, hearts were homogenized and tissue extracts were assayed for glutathione peroxidase (GSH-Px) and thioredoxin reductase (Thx-Red) activity. Sodium selenite, at a concentration of 0.5 microM, demonstrated a protective effect on the recovery of cardiac function following I-R, as evidenced by a lower end diastolic pressure and enhanced recovery of rate pressure product. There was no beneficial effect observed in hearts perfused with 0.1 microM sodium selenite-supplemented buffer, whereas poorer functional recovery was observed in hearts perfused with 10 microM sodium selenite-supplemented buffer. The beneficial effect of sodium selenite was not mediated through increased activity of GSH-Px or Thx-Red. This study demonstrates that the addition of sodium selenite to reperfusion solutions, at an optimal concentration of 0.5 microM, assists in cardiac recovery following ischemia reperfusion.
Collapse
Affiliation(s)
- Robyn Lymbury
- Heart Foundation Research Centre, School of Medical Science, Griffith University Gold Coast Campus, Southport, QLD, 9726. Australia
| | | | | |
Collapse
|
28
|
Abstract
Cardiac ischemia--reperfusion injury results in oxidative stress and poor physiological recovery. This study examined the amount of lipid and protein oxidation during ischemia-reperfusion to assess the degree of oxidative stress. Selenium supplementation was used to alter the antioxidant status of rats and the recovery of myocardial function post ischemia-reperfusion was investigated. Male Wistar rats were fed diets containing 0, 50, and 1000 microg/kg sodium selenite for 5 weeks, whilst controls received normal rat food containing 240 microg/kg selenium. Langendorff-perfused hearts were subjected to 22.5 min global ischemia and 45 min reperfusion, with functional recovery assessed. Heart tissues were assayed for the presence of lipid peroxides and protein carbonyls and correlated to cardiac recovery. Following ischemia and reperfusion there was a significant increase in both protein oxidation and lipid peroxidation. Hearts from selenium-deficient animals demonstrated higher levels of both protein carbonyls and lipid peroxides and were more susceptible to ischemia-reperfusion injury when compared to controls (38% versus 47% recovery of rate pressure product (RPP)). Selenium supplementation lowered the levels of protein carbonyls and lipid peroxides and resulted in improved recovery of cardiac function post ischemia-reperfusion (57% recovery of RPP). These data suggest that selenium supplementation may provide an effective method for reducing oxidative damage post cardiac ischemia-reperfusion.
Collapse
Affiliation(s)
- Kylie Venardos
- Heart Foundation Research Centre, Griffith University Gold Coast Campus, Southport, Queensland, Australia
| | | | | | | |
Collapse
|
29
|
Vanderlelie J, Venardos K, Clifton VL, Gude NM, Clarke FM, Perkins AV. Increased biological oxidation and reduced anti-oxidant enzyme activity in pre-eclamptic placentae. Placenta 2005; 26:53-8. [PMID: 15664411 DOI: 10.1016/j.placenta.2004.04.002] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/08/2004] [Indexed: 10/26/2022]
Abstract
Oxidative stress occurs when cellular levels of reactive oxygen species exceed anti-oxidant capabilities and has been implicated in the pathogenesis of pre-eclampsia. In this study we have examined the tissue levels of endogenous anti-oxidant proteins (superoxide dismutase, glutathione peroxidase, thioredoxin reductase and thioredoxin) and the level of lipid and protein oxidation in placental samples from normal and pre-eclamptic pregnancies. Pre-eclamptic tissue homogenates demonstrated significantly increased levels of lipid peroxidation (20.68 +/- 7.811 microM protein versus 5.33 +/- 4.03 microM/mg protein, P < 0.001) and a trended increase in protein carbonyl concentration (248.1 +/- 97.71 units/mg protein versus 209.7 +/- 82.6 U/mg protein) when compared to controls. The levels and activities of the anti-oxidant proteins superoxide dismutase (2.48 +/- 0.6 U/mg protein versus 2.02 +/- 0.51 U/mg protein, P <0.02), thioredoxin reductase (19.25 +/- 9.81 U/mg protein versus 13.02 +/- 5.66 U/mg protein,P = 0.02), thioredoxin (107.00 +/- 18.11 ng/mg protein versus 91.12 +/- 21.18 ng/mg protein, P = 0.02) and glutathione peroxidase (17.33 +/- 6.63 mmol/min/mg protein versus 11.50 +/- 3.11 mmol/min/mg, P < 0.02) were all found to be significantly reduced when comparing pre-eclamptic placental tissue homogenates to gestational age-matched control placentae from non-pre-eclamptic pregnancies. The results of this study demonstrate a decreased enzymatic anti-oxidant capacity and increased oxidation in placental tissue from pre-eclamptic women, which may contribute to the pathogenesis of this complex disorder.
Collapse
Affiliation(s)
- J Vanderlelie
- School of Health Science, Griffith University Gold Coast Campus, Parklands Drive, Southport, QLD 9726, Australia
| | | | | | | | | | | |
Collapse
|
30
|
Abstract
Cardiac ischemia reperfusion leads to oxidative stress and poor physiological recovery. Selenium deficiency down-regulates thioredoxin reductase (Txnrd) and glutathione peroxidase (Gpx) activity, impairing recovery from ischemia-reperfusion. Furthermore, selenium supplementation has been shown to be cardioprotective and lessens oxidative stress in reperfused rat hearts. In this study we have investigated the role of selenium in the mRNA expression of these, and related antioxidant proteins, post ischemia-reperfusion. Male rats were fed varying doses of selenium for five weeks. Hearts were isolated and perfused using the Langendorff method with 22.5 min of global ischemia and 45 min reperfusion. RNA was extracted for quantitative real-time PCR analysis of glutathione peroxidase (Gpx)-1 and 4, glutathione reductase (Gsr), thioredoxin peroxidase-2 (Prdx2), thioredoxin (Txn) and thioredoxin reductase (Txnrd)-1 and 2 gene expression. Selenium deficiency produced significant reductions in Gpx-1, Gpx-4, Prdx2, Txnrd-1 and Txnrd-2 expression. Conversely, selenium supplementation of 1000 microg/kg significantly up-regulated Gpx-1, Gpx-4, Txn, Txnrd-1 and Txnrd-2 transcription. Our results show selenium modulates the cardiac mRNA expression of thioredoxin and glutathione related enzymes post ischemia-reperfusion, and impacts on tolerance to ischemia-reperfusion.
Collapse
Affiliation(s)
- Kylie Venardos
- Heart Foundation Research Centre, School of Health Science, Griffith University Gold Coast Campus, Southport, Australia
| | | | | | | |
Collapse
|
31
|
Abstract
Epidemiological studies andin vitroanalysis demonstrate correlations between selenium status and human pre-eclampsia (PET). Selenium is an essential component in the anti-oxidant proteins glutathione peroxidase and thioredoxin reductase, which are produced in lower amounts in pre-eclamptic placenta. This study examined the effect of modulating dietary selenium content in pregnant rats. Rats were fed diets containing no selenium, 239 μg/kg selenium or 1000 μg/kg selenium, four weeks prior to and following conception. Significant pregnancy-specific increases in systolic blood pressure (116.4 ± 5.2 mmHg vs 108 ± 6.8 mmHg vs 111.4 ± 4.7 mmHg) and proteinuria (9.68 ± 2.12 μg/ml vs 5.93 ± 1.59 μg/ml vs 4.43 ± 0.96 μg/ml) were demonstrated in animals fed a selenium free-diet when compared with normal or high selenium diets. Placental weight and pup number were not affected by selenium deprivation, however a significant decrease in the pup weight was evident. Selenium deprivation caused dose-dependent decreases in liver glutathione peroxidase (28.55 ± 3.82 mmoles/min/mg vs 34.68 ± 8.64 mmoles/min/mg) and thioredoxin reductase (2.37 ± 1.25 U/mg vs 6.68 ± 1.82 U/mg) activity, whereas superoxide dismutase activity remained constant. Placental activity of these enzymes also decreased leading to oxidative stress as measured by increased lipid peroxides (17.92 ± 1.78 μmoles/mg vs 8.30 ± 5.52 μmoles/mg) and protein carbonyls in tissue extracts from selenium-free animals. These results suggest that selenium deficiency in pregnant rats leads to symptoms similar to those seen in human PET and may provide an experimental model for studying this complex disease.
Collapse
Affiliation(s)
- J Vanderlelie
- School of Health Science, Griffith University Gold Coast Campus, Southport, QLD 9726, Australia
| | | | | |
Collapse
|
32
|
Abstract
Auranofin, an antirheumatic gold compound, is an inhibitor of selenocysteine enzymes, such as thioredoxin reductase and glutathione peroxidase. These enzymes play an important role in protecting cardiac tissue from oxidative stress generated during ischaemia-reperfusion. Auranofin (100 mg/kg) was administered to rats and their hearts were subjected to an in vitro model of ischaemia-reperfusion. The activity of thioredoxin reductase and glutathione peroxidase was determined in liver and heart tissues in an attempt to correlate enzymatic activity with heart recovery after ischaemia-reperfusion. There was significantly less thioredoxin reductase activity in rat liver extracts, whereas the level of glutathione activity remained unchanged, demonstrating that the dose of auranofin used was able to selectively inhibit one of these enzyme systems. Rats administered auranofin displayed significantly impaired recovery from ischaemic insult. The end diastolic pressure was increased, whereas the rate pressure product was significantly decreased. The level of postischaemic apoptosis was also assessed by examining caspase-3 activity in tissue homogenates. Auranofin significantly increased the degree of postischaemic apoptosis, leading to poor postischaemic recovery.
Collapse
Affiliation(s)
- Kylie Venardos
- Heart Foundation Research Centre, Griffith University Gold Coast Campus, Southport, Queensland, Australia
| | | | | | | |
Collapse
|
33
|
Venardos K, Harrison G, Headrick J, Perkins A. Effects of dietary selenium on glutathione peroxidase and thioredoxin reductase activity and recovery from cardiac ischemia-reperfusion. J Trace Elem Med Biol 2004; 18:81-8. [PMID: 15487768 DOI: 10.1016/j.jtemb.2004.01.001] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Glutathione peroxidase and thioredoxin reductase are selenocysteine-dependent enzymes that protect against oxidative injury. This study examined the effects of dietary selenium on the activity of these two enzymes in rats, and investigated the ability of selenium to modulate myocardial function post ischemia-reperfusion. Male wistar rats were fed diets containing 0, 50, 240 and 1000 microg/kg sodium selenite for 5 weeks. Langendorff perfused hearts isolated from these rats were subjected to 22.5 min global ischemia and 45 min reperfusion, with functional recovery assessed. Liver samples were collected at the time of sacrifice, and heart and liver tissues assayed for thioredoxin reductase and glutathione peroxidase activity. Selenium deficiency reduced the activity of both glutathione peroxidase and thioredoxin reductase systemically. Hearts from selenium deficient animals were more susceptible to ischemia-reperfusion injury when compared to normal controls (38% recovery of rate pressure product (RPP) vs. 47% recovery of RPP). Selenium supplementation increased the endogenous activity of thioredoxin reductase and glutathione peroxidase and resulted in improved recovery of cardiac function post ischemia reperfusion (57% recovery of RPP). Endogenous activity of glutathione peroxidase and thioredoxin reductase is dependent on an adequate supply of the micronutrient selenium. Reduced activity of these antioxidant enzymes is associated with significant reductions in myocardial function post ischemia-reperfusion.
Collapse
Affiliation(s)
- Kylie Venardos
- Heart Foundation Research Centre, School of Health Science, Griffith University Gold Coast Campus, Southpor QLD 4217, Australia
| | | | | | | |
Collapse
|