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Yadid M, Lind JU, Ardoña HAM, Sheehy SP, Dickinson LE, Eweje F, Bastings MMC, Pope B, O'Connor BB, Straubhaar JR, Budnik B, Kleber AG, Parker KK. Endothelial extracellular vesicles contain protective proteins and rescue ischemia-reperfusion injury in a human heart-on-chip. Sci Transl Med 2021; 12:12/565/eaax8005. [PMID: 33055246 DOI: 10.1126/scitranslmed.aax8005] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 09/08/2020] [Indexed: 12/17/2022]
Abstract
Extracellular vesicles (EVs) derived from various stem cell sources induce cardioprotective effects during ischemia-reperfusion injury (IRI). These have been attributed mainly to the antiapoptotic, proangiogenic, microRNA (miRNA) cargo within the stem cell-derived EVs. However, the mechanisms of EV-mediated endothelial signaling to cardiomyocytes, as well as their therapeutic potential toward ischemic myocardial injury, are not clear. EV content beyond miRNA that may contribute to cardioprotection has not been fully illuminated. This study characterized the protein cargo of human vascular endothelial EVs (EEVs) to identify lead cardioactive proteins and assessed the effect of EEVs on human laminar cardiac tissues (hlCTs) exposed to IRI. We mapped the protein content of human vascular EEVs and identified proteins that were previously associated with cellular metabolism, redox state, and calcium handling, among other processes. Analysis of the protein landscape of human cardiomyocytes revealed corresponding modifications induced by EEV treatment. To assess their human-specific cardioprotection in vitro, we developed a human heart-on-a-chip IRI assay using human stem cell-derived, engineered cardiac tissues. We found that EEVs alleviated cardiac cell death as well as the loss in contractile capacity during and after simulated IRI in an uptake- and dose-dependent manner. Moreover, we found that EEVs increased the respiratory capacity of normoxic cardiomyocytes. These results suggest that vascular EEVs rescue hlCTs exposed to IRI possibly by supplementing injured myocytes with cargo that supports multiple metabolic and salvage pathways and therefore may serve as a multitargeted therapy for IRI.
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Affiliation(s)
- Moran Yadid
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Johan U Lind
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA.,Department of Health Technology, Technical University of Denmark, Kgs. Lyngby 2800, Denmark
| | - Herdeline Ann M Ardoña
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Sean P Sheehy
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Lauren E Dickinson
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Feyisayo Eweje
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Maartje M C Bastings
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.,Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA.,Ecole Polytechnique Federale Lausanne (EPFL), School of Engineering, Institute of Materials, Programmable Biomaterials Laboratory, Station 12, 1015 Lausanne, Switzerland
| | - Benjamin Pope
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA.,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Blakely B O'Connor
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | | | - Bogdan Budnik
- FAS Division of Science, Harvard University, Cambridge, MA 02138, USA
| | - Andre G Kleber
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
| | - Kevin Kit Parker
- Disease Biophysics Group, John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA. .,Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA 02115, USA
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Zhao Q, Wu J, Hua Q, Lin Z, Ye L, Zhang W, Wu G, Du J, Xia J, Chu M, Hu X. Resolvin D1 mitigates energy metabolism disorder after ischemia-reperfusion of the rat lung. J Transl Med 2016; 14:81. [PMID: 27009328 PMCID: PMC4806414 DOI: 10.1186/s12967-016-0835-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 03/16/2016] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Energy metabolism disorder is a critical process in lung ischemia-reperfusion injury (LIRI). This study was aimed to determine the effects of resolvin D1 (RvD1) on the energy metabolism in LIRI. METHODS Forty Sprague-Dawley rats were divided into the following groups: Sham group; untreated ischemia-reperfusion (IR) control; IR treated with normal saline (IR-NS); and IR treated with RvD1 (IR-RV) (100 μg/kg, iv). LIRI and energy metabolism disorder were determined in these rats. RESULTS The results revealed that the levels of interleukin (IL)-1β, tumor necrosis factor-α, IL-10, monocyte chemoattractant protein-1, macrophage inflammatory protein-2, cytokine-induced neutrophil chemoattractant-1, injured alveoli rate, apoptosis index, pulmonary permeability index, malondialdehyde, ADP, and lactic acid were increased, whereas the levels of ATP, ATP/ADP, glycogen, Na(+)-K(+)-ATPase, superoxide dismutase, glutathione peroxidase activity, pulmonary surfactant associated protein-A, and oxygenation index were decreased in rats with LIRI. Except for IL-10, all these biomarkers of LIRI and its related energy metabolism disorder were significantly inhibited by RvD1 treatment. In addition, histological analysis via hematoxylin-eosin staining, and transmission electron microscopy confirmed that IR-induced structure damages of lung tissues were reduced by RvD1. CONCLUSION RvD1 improves the energy metabolism of LIRI disturbance, protects the mitochondrial structure and function, increases the ATP, glycogen content and Na(+)-K(+)-ATPase activity of lung tissue, balances the ratio of ATP/ADP and finally decreases the rate of apoptosis, resulting in the protection of IR-induced lung injury. The improved energy metabolism after LIRI may be related to the reduced inflammatory response, the balance of the oxidative/antioxidant and the pro-inflammatory/anti-inflammatory systems in rats.
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Affiliation(s)
- Qifeng Zhao
- The Department of Children's Cardiovascular and Thoracic Surgery, Children's Heart Center, the Second Affiliated Hospital, Yuying Children's Hospital, Institute of Cardiovascular Development and Translational Medicine, Wenzhou Medical University, 325000, Wenzhou, People's Republic of China
| | - Ji Wu
- Wuhan Medical & Healthcare Center for Woman and Children, 430015, Wuhan, People's Republic of China
| | - Qingwang Hua
- The Department of Children's Cardiovascular and Thoracic Surgery, Children's Heart Center, the Second Affiliated Hospital, Yuying Children's Hospital, Institute of Cardiovascular Development and Translational Medicine, Wenzhou Medical University, 325000, Wenzhou, People's Republic of China
| | - Zhiyong Lin
- The Department of Children's Cardiovascular and Thoracic Surgery, Children's Heart Center, the Second Affiliated Hospital, Yuying Children's Hospital, Institute of Cardiovascular Development and Translational Medicine, Wenzhou Medical University, 325000, Wenzhou, People's Republic of China
| | - Leping Ye
- The Department of Children's Respiration Medicine, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, 325000, Wenzhou, People's Republic of China
| | - Weixi Zhang
- The Department of Children's Respiration Medicine, The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, 325000, Wenzhou, People's Republic of China
| | - Guowei Wu
- The Department of Children's Cardiovascular and Thoracic Surgery, Children's Heart Center, the Second Affiliated Hospital, Yuying Children's Hospital, Institute of Cardiovascular Development and Translational Medicine, Wenzhou Medical University, 325000, Wenzhou, People's Republic of China
| | - Jie Du
- The Department of Children's Cardiovascular and Thoracic Surgery, Children's Heart Center, the Second Affiliated Hospital, Yuying Children's Hospital, Institute of Cardiovascular Development and Translational Medicine, Wenzhou Medical University, 325000, Wenzhou, People's Republic of China
| | - Jie Xia
- The Department of Children's Cardiovascular and Thoracic Surgery, Children's Heart Center, the Second Affiliated Hospital, Yuying Children's Hospital, Institute of Cardiovascular Development and Translational Medicine, Wenzhou Medical University, 325000, Wenzhou, People's Republic of China
| | - Maoping Chu
- The Department of Children's Cardiovascular Medicine, Children's Heart Center, the Second Affiliated Hospital, Yuying Children's Hospital, Institute of Cardiovascular Development and Translational Medicine, Wenzhou Medical University, 325000, Wenzhou, People's Republic of China
| | - Xingti Hu
- The Department of Children's Cardiovascular and Thoracic Surgery, Children's Heart Center, the Second Affiliated Hospital, Yuying Children's Hospital, Institute of Cardiovascular Development and Translational Medicine, Wenzhou Medical University, 325000, Wenzhou, People's Republic of China.
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Hu S, Liu WW, Zhao Y, Lin ZL, Luo HM, Bai XD, Sheng ZY, Zhou FQ. Pyruvate-enriched oral rehydration solution improved intestinal absorption of water and sodium during enteral resuscitation in burns. Burns 2013; 40:693-701. [PMID: 24280524 DOI: 10.1016/j.burns.2013.09.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 08/19/2013] [Accepted: 09/05/2013] [Indexed: 10/26/2022]
Abstract
AIM To investigate alteration in intestinal absorption during enteral resuscitation with pyruvate-enriched oral rehydration solution (Pyr-ORS) in scalded rats. METHODS To compare pyruvate-enriched oral rehydration solution (Pyr-ORS) with World Health Organisation oral rehydration solution (WHO-ORS), 120 rats were randomly divided into 6 groups and 2 subgroups. At 1.5 and 4.5 h after a 35% TBSA scald, the intestinal absorption rate, mucosal blood flow (IMBF), Na(+)-K(+)-ATPase activity and aquaporin-1 (AQP-1) expression were determined (n = 10), respectively. RESULTS The intestinal Na(+)-K(+)-ATPase activity, AQP-1 expression and IMBF were markedly decreased in scald groups, but they were profoundly preserved by enteral resuscitation with WHO-ORS and further improved significantly with Pyr-ORS at both time points. Na(+)-K+-ATPase activities remained higher in enteral resuscitation with Pyr-ORS (Group SP) than those with WHO-ORS (Group SW) at 4.5 h. AQP-1 and IMBF were significantly greater in Group SP than in Group SW at both time points. Intestinal absorption rates of water and sodium were obviously inhibited in scald groups; however, rates were also significantly preserved in Group SP than in Group SW with an over 20% increment at both time points. CONCLUSION The Pyr-ORS may be superior to the standard WHO-ORS in the promotion of intestinal absorption of water and sodium during enteral resuscitation.
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Affiliation(s)
- Sen Hu
- Laboratory of Shock and Organ Dysfunction, Burns Institute, the First Hospital Affiliated to the People's Liberation Army General Hospital, No. 51 Fu-cheng Road, Beijing 100048, China
| | - Wei-wei Liu
- Department of Burns and Plastic Surgery, The Armed Police General Hospital of People's Liberation Army, No. 69 Yong-ding Road, Beijing 100039, China
| | - Ying Zhao
- Department of Burns and Plastic Surgery, The Armed Police General Hospital of People's Liberation Army, No. 69 Yong-ding Road, Beijing 100039, China
| | - Zhi-long Lin
- Department of Burns and Plastic Surgery, The Armed Police General Hospital of People's Liberation Army, No. 69 Yong-ding Road, Beijing 100039, China
| | - Hong-min Luo
- Laboratory of Shock and Organ Dysfunction, Burns Institute, the First Hospital Affiliated to the People's Liberation Army General Hospital, No. 51 Fu-cheng Road, Beijing 100048, China
| | - Xiao-dong Bai
- Department of Burns and Plastic Surgery, The Armed Police General Hospital of People's Liberation Army, No. 69 Yong-ding Road, Beijing 100039, China.
| | - Zhi-yong Sheng
- Laboratory of Shock and Organ Dysfunction, Burns Institute, the First Hospital Affiliated to the People's Liberation Army General Hospital, No. 51 Fu-cheng Road, Beijing 100048, China
| | - Fang-qiang Zhou
- Fresenius Dialysis Centers at Chicago, Rolling Meadows Facility, No. 4180 Winnetka Ave, Rolling Meadows, IL 60008, USA.
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Mellor KM, Bell JR, Ritchie RH, Delbridge LMD. Myocardial insulin resistance, metabolic stress and autophagy in diabetes. Clin Exp Pharmacol Physiol 2013; 40:56-61. [PMID: 22804725 DOI: 10.1111/j.1440-1681.2012.05738.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 06/15/2012] [Accepted: 06/18/2012] [Indexed: 01/19/2023]
Abstract
Clinical studies in humans strongly support a link between insulin resistance and non-ischaemic heart failure. The occurrence of a specific insulin-resistant cardiomyopathy, independent of vascular abnormalities, is now recognized. The progression of cardiac pathology linked with insulin resistance is poorly understood. Cardiac insulin resistance is characterized by reduced availability of sarcolemmal Glut-4 transporters and consequent lower glucose uptake. A shift away from glycolysis towards fatty acid oxidation for ATP supply is apparent and is associated with myocardial oxidative stress. Reliance of cardiomyocyte excitation-contraction coupling on glycolytically derived ATP supply potentially renders cardiac function vulnerable to the metabolic remodelling adaptations observed in diabetes development. Findings from Glut-4-knockout mice demonstrate that cardiomyocytes with extreme glucose uptake deficiency exhibit cardiac hypertrophy and marked excitation-contraction coupling abnormalities characterized by reduced sarcolemmal Ca(2+) influx and sarcoplasmic reticulum Ca(2+) uptake. The 'milder' phenotype fructose-fed mouse model of type 2 diabetes does not show evidence of cardiac hypertrophy, but cardiomyocyte loss linked with autophagic activation is evident. Fructose feeding induces a marked reduction in intracellular Ca(2+) availability with myofilament adaptation to preserve contractile function in this setting. The cardiac metabolic adaptations of two load-independent models of diabetes, namely the Glut-4-deficient mouse and the fructose-fed mouse are contrasted. The role of autophagy in diabetic cardiopathology is evaluated and anomalies of type 1 versus type 2 diabetic autophagic responses are highlighted.
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Affiliation(s)
- Kimberley M Mellor
- Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
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Regulation of ion gradients across myocardial ischemic border zones: a biophysical modelling analysis. PLoS One 2013; 8:e60323. [PMID: 23577101 PMCID: PMC3618345 DOI: 10.1371/journal.pone.0060323] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Accepted: 02/24/2013] [Indexed: 12/19/2022] Open
Abstract
The myocardial ischemic border zone is associated with the initiation and sustenance of arrhythmias. The profile of ionic concentrations across the border zone play a significant role in determining cellular electrophysiology and conductivity, yet their spatial-temporal evolution and regulation are not well understood. To investigate the changes in ion concentrations that regulate cellular electrophysiology, a mathematical model of ion movement in the intra and extracellular space in the presence of ionic, potential and material property heterogeneities was developed. The model simulates the spatial and temporal evolution of concentrations of potassium, sodium, chloride, calcium, hydrogen and bicarbonate ions and carbon dioxide across an ischemic border zone. Ischemia was simulated by sodium-potassium pump inhibition, potassium channel activation and respiratory and metabolic acidosis. The model predicted significant disparities in the width of the border zone for each ionic species, with intracellular sodium and extracellular potassium having discordant gradients, facilitating multiple gradients in cellular properties across the border zone. Extracellular potassium was found to have the largest border zone and this was attributed to the voltage dependence of the potassium channels. The model also predicted the efflux of [Formula: see text] from the ischemic region due to electrogenic drift and diffusion within the intra and extracellular space, respectively, which contributed to [Formula: see text] depletion in the ischemic region.
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Lai RC, Yeo RWY, Tan KH, Lim SK. Mesenchymal stem cell exosome ameliorates reperfusion injury through proteomic complementation. Regen Med 2013; 8:197-209. [DOI: 10.2217/rme.13.4] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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Fuller W, Tulloch LB, Shattock MJ, Calaghan SC, Howie J, Wypijewski KJ. Regulation of the cardiac sodium pump. Cell Mol Life Sci 2012; 70:1357-80. [PMID: 22955490 PMCID: PMC3607738 DOI: 10.1007/s00018-012-1134-y] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 07/27/2012] [Accepted: 08/13/2012] [Indexed: 01/24/2023]
Abstract
In cardiac muscle, the sarcolemmal sodium/potassium ATPase is the principal quantitative means of active transport at the myocyte cell surface, and its activity is essential for maintaining the trans-sarcolemmal sodium gradient that drives ion exchange and transport processes that are critical for cardiac function. The 72-residue phosphoprotein phospholemman regulates the sodium pump in the heart: unphosphorylated phospholemman inhibits the pump, and phospholemman phosphorylation increases pump activity. Phospholemman is subject to a remarkable plethora of post-translational modifications for such a small protein: the combination of three phosphorylation sites, two palmitoylation sites, and one glutathionylation site means that phospholemman integrates multiple signaling events to control the cardiac sodium pump. Since misregulation of cytosolic sodium contributes to contractile and metabolic dysfunction during cardiac failure, a complete understanding of the mechanisms that control the cardiac sodium pump is vital. This review explores our current understanding of these mechanisms.
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Affiliation(s)
- W Fuller
- Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, College of Medicine Dentistry and Nursing, University of Dundee, Dundee, UK.
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Szmit S, Jank M, Maciejewski H, Balsam P, Majewska A, Loj M, Grabowski M, Filipiak KJ, Motyl T, Opolski G. White blood cell transcriptome correlates with renal function in acute heart failure. Int Heart J 2012; 53:117-24. [PMID: 22688316 DOI: 10.1536/ihj.53.117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
It is notoriously difficult to classify patients with acute heart failure (AHF) because of variations in clinical presentation, different etiologies, the impact of comorbidities, and variable prognoses. In this study, we used DNA whole-genome microarrays to classify 24 patients with AHF based on the transcriptome of their peripheral blood nuclear cells. The main purpose was to verify whether any transcriptomic sub-clusters had clinical correlations. We identified two distinct groups of transcriptomic profiles that correlated with normal (1.125 mg/dL) and increased (1.783 mg/dL) mean blood creatinine concentrations. These two subgroups of patients (n = 12) differed in the expression of more than 6000 genes and 108 signaling pathways. The most significant regulated signaling pathway was the aldosterone-regulated sodium reabsorption pathway and the most significant regulated genes included the angiotensin-converting enzyme gene. This suggests that kidney impairment in patients with AHF is related to dysregulation of the renin-angiotensin-aldosterone system. The interesting findings of our study were the significant differences in expression of genes belonging to the aldosterone-regulated signaling pathway: Na<sup>+</sup>/K<sup>+</sup> transporting ATPase and NEDD4L (neuronal precursor cell expressed developmentally down-regulated 4-like) between patients with and without renal dysfunction. Future studies of blood-cell transcriptomic profiles in patients with AHF will provide further insights into the molecular pathogenesis of this cardiorenal disorder.
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Affiliation(s)
- Sebastian Szmit
- First Department of Cardiology, Medical University of Warsaw, Poland
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Mellor KM, Wendt IR, Ritchie RH, Delbridge LMD. Fructose diet treatment in mice induces fundamental disturbance of cardiomyocyte Ca2+ handling and myofilament responsiveness. Am J Physiol Heart Circ Physiol 2011; 302:H964-72. [PMID: 22198170 DOI: 10.1152/ajpheart.00797.2011] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
High fructose intake has been linked to insulin resistance and cardiac pathology. Dietary fructose-induced myocardial signaling and morphological alterations have been described, but whether cardiomyocyte function is influenced by chronic high fructose intake is yet to be elucidated. The goal of this study was to evaluate the cardiomyocyte excitation-contraction coupling effects of high dietary fructose and determine the capacity for murine cardiomyocyte fructose transport. Male C57Bl/6J mice were fed a high fructose diet for 12 wk. Fructose- and control-fed mouse cardiomyocytes were isolated and loaded with the fura 2 Ca(2+) fluorescent dye for analysis of twitch and Ca(2+) transient characteristics (4 Hz stimulation, 37°C, 2 mM Ca(2+)). Myocardial Ca(2+)-handling protein expression was determined by Western blot. Gene expression of the fructose-specific transporter, GLUT5, in adult mouse cardiomyocytes was detected by real-time and conventional RT-PCR techniques. Diastolic Ca(2+) and Ca(2+) transient amplitude were decreased in isolated cardiomyocytes from fructose-fed mice relative to control (16 and 42%, respectively), coincident with an increase in the time constant of Ca(2+) transient decay (24%). Dietary fructose increased the myofilament response to Ca(2+) (as evidenced by a left shift in the shortening-Ca(2+) phase loop). Protein expression of sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2a), phosphorylated (P) phospholamban (Ser(16)), and P-phospholamban (Thr(17)) was reduced, and protein phosphatase 2A expression increased, in fructose-fed mouse hearts. Hypertension and cardiac hypertrophy were not evident. These findings demonstrate that fructose diet-associated myocardial insulin resistance induces profound disturbance of cardiomyocyte Ca(2+) handling and responsiveness in the absence of altered systemic loading conditions.
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Affiliation(s)
- Kimberley M Mellor
- Dept. of Physiology, Univ. of Melbourne, Parkville, Victoria, Australia 3010
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Mellor KM, Bell JR, Wendt IR, Davidoff AJ, Ritchie RH, Delbridge LMD. Fructose modulates cardiomyocyte excitation-contraction coupling and Ca²⁺ handling in vitro. PLoS One 2011; 6:e25204. [PMID: 21980397 PMCID: PMC3182977 DOI: 10.1371/journal.pone.0025204] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 08/30/2011] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND High dietary fructose has structural and metabolic cardiac impact, but the potential for fructose to exert direct myocardial action is uncertain. Cardiomyocyte functional responsiveness to fructose, and capacity to transport fructose has not been previously demonstrated. OBJECTIVE The aim of the present study was to seek evidence of fructose-induced modulation of cardiomyocyte excitation-contraction coupling in an acute, in vitro setting. METHODS AND RESULTS The functional effects of fructose on isolated adult rat cardiomyocyte contractility and Ca²⁺ handling were evaluated under physiological conditions (37°C, 2 mM Ca²⁺, HEPES buffer, 4 Hz stimulation) using video edge detection and microfluorimetry (Fura2) methods. Compared with control glucose (11 mM) superfusate, 2-deoxyglucose (2 DG, 11 mM) substitution prolonged both the contraction and relaxation phases of the twitch (by 16 and 36% respectively, p<0.05) and this effect was completely abrogated with fructose supplementation (11 mM). Similarly, fructose prevented the Ca²⁺ transient delay induced by exposure to 2 DG (time to peak Ca²⁺ transient: 2 DG: 29.0±2.1 ms vs. glucose: 23.6±1.1 ms vs. fructose +2 DG: 23.7±1.0 ms; p<0.05). The presence of the fructose transporter, GLUT5 (Slc2a5) was demonstrated in ventricular cardiomyocytes using real time RT-PCR and this was confirmed by conventional RT-PCR. CONCLUSION This is the first demonstration of an acute influence of fructose on cardiomyocyte excitation-contraction coupling. The findings indicate cardiomyocyte capacity to transport and functionally utilize exogenously supplied fructose. This study provides the impetus for future research directed towards characterizing myocardial fructose metabolism and understanding how long term high fructose intake may contribute to modulating cardiac function.
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Affiliation(s)
- Kimberley M Mellor
- Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia.
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Morita N, Lee JH, Bapat A, Fishbein MC, Mandel WJ, Chen PS, Weiss JN, Karagueuzian HS. Glycolytic inhibition causes spontaneous ventricular fibrillation in aged hearts. Am J Physiol Heart Circ Physiol 2011; 301:H180-91. [PMID: 21478408 DOI: 10.1152/ajpheart.00128.2011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Selective glycolytic inhibition (GI) promotes electromechanical alternans and triggered beats in isolated cardiac myocytes. We sought to determine whether GI promotes triggered activity by early afterdepolarization (EAD) or delayed afterdepolarizations in intact hearts isolated from adult and aged rats. Dual voltage and intracellular calcium ion (Ca(i)(2+)) fluorescent optical maps and single cell glass microelectrode recordings were made from the left ventricular (LV) epicardium of isolated Langendorff-perfused adult (∼4 mo) and aged (∼24 mo) rat hearts. GI was induced by replacing glucose with 10 mM pyruvate in oxygenated Tyrode's. Within 20 min, GI slowed Ca(i)(2+) transient decline rate and shortened action potential duration in both groups. These changes were associated with ventricular fibrillation (VF) in the aged hearts (64 out of 66) but not in adult hearts (0 out of 18; P < 0.001). VF was preceded by a transient period of focal ventricular tachycardia caused by EAD-mediated triggered activity leading to VF within seconds. The VF was suppressed by the ATP-sensitive K (K(ATP)) channel blocker glibenclamide (1 μM) but not (0 out of 7) by mitochondrial K(ATP) block. The Ca-calmodulin-dependent protein kinase II (CaMKII) blocker KN-93 (1 μM) prevented GI-mediated VF (P < 0.05). Block of Na-Ca exchanger (NCX) by SEA0400 (2 μM) prevented GI-mediated VF (3 out of 6), provided significant bradycardia did not occur. Aged hearts had significantly greater LV fibrosis and reduced connexin 43 than adult hearts (P < 0.05). We conclude that in aged fibrotic unlike in adult rat hearts, GI promotes EADs, triggered activity, and VF by activation of K(ATP) channels CaMKII and NCX.
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Affiliation(s)
- Norishige Morita
- Translational Arrhythmia Research Section, Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, 675 Charles E. Young Dr. South, MRL 3645 Mail Code: 176022, Los Angeles, CA 90095, USA
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Nielles-Vallespin S, Weber MA, Bock M, Bongers A, Speier P, Combs SE, Wöhrle J, Lehmann-Horn F, Essig M, Schad LR. 3D radial projection technique with ultrashort echo times for sodium MRI: clinical applications in human brain and skeletal muscle. Magn Reson Med 2007; 57:74-81. [PMID: 17191248 DOI: 10.1002/mrm.21104] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
(23)Na MRI has the potential to noninvasively detect sodium (Na) content changes in vivo. The goal of this study was to implement (23)Na MRI in a clinical setting for neurooncological and muscular imaging. Due to the biexponential T(2) decay of the tissue Na signal with a short component, which ranges between 0.5-8 ms, the measurement of total Na content requires imaging techniques with echo times (TEs) below 0.5 ms. A 3D radial pulse sequence with a TE of 0.2 ms at a spatial resolution of 4 x 4 x 4 mm(3) was developed that allows the acquisition and presentation of Na images on the scanner. This sequence was evaluated in patients with low- and high-grade gliomas, and higher (23)Na MR signals corresponding to an increased Na content were found in the tumor regions. The contrast-to-noise ratio (CNR) between tumor and white matter increased from 0.8 +/- 0.2 to 1.3 +/- 0.3 with tumor grade. In patients with an identified muscular (23)Na channelopathy (Paramyotonia congenita (PC)), induced muscle weakness led to a signal increase of approximately 18% in the (23)Na MR images, which was attributed to intracellular Na(+) accumulation in this region.
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Lankford AR, Byford AM, Ashton KJ, French BA, Lee JK, Headrick JP, Matherne GP. Gene expression profile of mouse myocardium with transgenic overexpression of A1 adenosine receptors. Physiol Genomics 2002; 11:81-9. [PMID: 12388787 DOI: 10.1152/physiolgenomics.00008.2002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Transgenic mice with cardiac-specific overexpression of adenosine A(1) receptors (A(1)AR) have demonstrated metabolic and functional tolerance to myocardial ischemia. We utilized cDNA microarrays to test the hypothesis that the cardioprotective mechanism(s) of A(1) overexpression involves altered gene expression. Total RNA extracted from the left ventricles from A(1) transgenic (n = 4) and wild-type (n = 6) mice was hybridized to Affymetrix mgU74A chips. Comparison of RNA expression levels in transgenic to wild-type myocardium revealed approximately 636 known genes with expression significantly altered by greater than 25%. We observed increased expressions of genes including NADH dehydrogenase, the GLUT4 glucose transporter, Na-K-ATPase, sarcolemmal K(ATP) channels, and Bcl-xl in A(1)AR-overexpressing hearts. We also observed decreased expression of pro-apoptotic genes including a 50% reduction in message level of caspase-8. Protein expression of GLUT4 and caspase-8 was also altered comparable to the differences in gene expression. These data illustrate genes with chronically altered patterns of expression in A(1) transgenic mouse myocardium that may be related to adenosine receptor overexpression-mediated cardioprotection.
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Affiliation(s)
- Amy R Lankford
- Department of Pediatrics and Cardiovascular Research Center, University of Virginia Health System, Charlottesville Virginia 22908, USA.
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