1
|
Watson SA, Scigliano M, Bardi I, Ascione R, Terracciano CM, Perbellini F. Preparation of viable adult ventricular myocardial slices from large and small mammals. Nat Protoc 2017; 12:2623-2639. [PMID: 29189769 DOI: 10.1038/nprot.2017.139] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This protocol describes the preparation of highly viable adult ventricular myocardial slices from the hearts of small and large mammals, including rodents, pigs, dogs and humans. Adult ventricular myocardial slices are 100- to 400-μm-thick slices of living myocardium that retain the native multicellularity, architecture and physiology of the heart. This protocol provides a list of the equipment and reagents required alongside a detailed description of the methodology for heart explantation, tissue preparation, slicing with a vibratome and handling of myocardial slices. Supplementary videos are included to visually demonstrate these steps. A number of critical steps are addressed that must be followed in order to prepare highly viable myocardial slices. These include identification of myocardial fiber direction and fiber alignment within the tissue block, careful temperature control, use of an excitation-contraction uncoupler, optimal vibratome settings and correct handling of myocardial slices. Many aspects of cardiac structure and function can be studied using myocardial slices in vitro. Typical results obtained with hearts from a small mammal (rat) and a large mammal (human) with heart failure are shown, demonstrating myocardial slice viability, maximum contractility, Ca2+ handling and structure. This protocol can be completed in ∼4 h.
Collapse
Affiliation(s)
- Samuel A Watson
- Division of Cardiovascular Sciences, Myocardial Function, National Heart and Lung Institute, Imperial College London, London, UK
| | - Martina Scigliano
- Division of Cardiovascular Sciences, Myocardial Function, National Heart and Lung Institute, Imperial College London, London, UK
| | - Ifigeneia Bardi
- Division of Cardiovascular Sciences, Myocardial Function, National Heart and Lung Institute, Imperial College London, London, UK
| | - Raimondo Ascione
- Translational Biomedical Research Centre, University of Bristol, Bristol, UK
| | - Cesare M Terracciano
- Division of Cardiovascular Sciences, Myocardial Function, National Heart and Lung Institute, Imperial College London, London, UK
| | - Filippo Perbellini
- Division of Cardiovascular Sciences, Myocardial Function, National Heart and Lung Institute, Imperial College London, London, UK
| |
Collapse
|
2
|
Hafstad AD, Boardman N, Aasum E. How exercise may amend metabolic disturbances in diabetic cardiomyopathy. Antioxid Redox Signal 2015; 22:1587-605. [PMID: 25738326 PMCID: PMC4449627 DOI: 10.1089/ars.2015.6304] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
SIGNIFICANCE Over-nutrition and sedentary lifestyle has led to a worldwide increase in obesity, insulin resistance, and type 2 diabetes (T2D) associated with an increased risk of development of cardiovascular disorders. Diabetic cardiomyopathy, independent of hypertension or coronary disease, is induced by a range of systemic changes and may through multiple processes result in functional and structural cardiac derangements. The pathogenesis of this cardiomyopathy is complex and multifactorial, and it will eventually lead to reduced cardiac working capacity and increased susceptibility to ischemic injury. RECENT ADVANCES Metabolic disturbances such as altered lipid handling and substrate utilization, decreased mechanical efficiency, mitochondrial dysfunction, disturbances in nonoxidative glucose pathways, and increased oxidative stress are hallmarks of diabetic cardiomyopathy. Interestingly, several of these disturbances are found to precede the development of cardiac dysfunction. CRITICAL ISSUES Exercise training is effective in the prevention and treatment of obesity and T2D. In addition to its beneficial influence on diabetes/obesity-related systemic changes, it may also amend many of the metabolic disturbances characterizing the diabetic myocardium. These changes are due to both indirect effects, exercise-mediated systemic changes, and direct effects originating from the high contractile activity of the heart during physical training. FUTURE DIRECTIONS Revealing the molecular mechanisms behind the beneficial effects of exercise training is of considerable scientific value to generate evidence-based therapy and in the development of new treatment strategies.
Collapse
Affiliation(s)
- Anne D Hafstad
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Neoma Boardman
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Ellen Aasum
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT-The Arctic University of Norway, Tromsø, Norway
| |
Collapse
|
3
|
Lund J, Hafstad AD, Boardman NT, Rossvoll L, Rolim NP, Ahmed MS, Florholmen G, Attramadal H, Wisløff U, Larsen TS, Aasum E. Exercise training promotes cardioprotection through oxygen-sparing action in high fat-fed mice. Am J Physiol Heart Circ Physiol 2015; 308:H823-9. [PMID: 25637547 DOI: 10.1152/ajpheart.00734.2014] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 01/28/2015] [Indexed: 11/22/2022]
Abstract
Although exercise training has been demonstrated to have beneficial cardiovascular effects in diabetes, the effect of exercise training on hearts from obese/diabetic models is unclear. In the present study, mice were fed a high-fat diet, which led to obesity, reduced aerobic capacity, development of mild diastolic dysfunction, and impaired glucose tolerance. Following 8 wk on high-fat diet, mice were assigned to 5 weekly high-intensity interval training (HIT) sessions (10 × 4 min at 85-90% of maximum oxygen uptake) or remained sedentary for the next 10 constitutive weeks. HIT increased maximum oxygen uptake by 13%, reduced body weight by 16%, and improved systemic glucose homeostasis. Exercise training was found to normalize diastolic function, attenuate diet-induced changes in myocardial substrate utilization, and dampen cardiac reactive oxygen species content and fibrosis. These changes were accompanied by normalization of obesity-related impairment of mechanical efficiency due to a decrease in work-independent myocardial oxygen consumption. Finally, we found HIT to reduce infarct size by 47% in ex vivo hearts subjected to ischemia-reperfusion. This study therefore demonstrated for the first time that exercise training mediates cardioprotection following ischemia in diet-induced obese mice and that this was associated with oxygen-sparing effects. These findings highlight the importance of optimal myocardial energetics during ischemic stress.
Collapse
Affiliation(s)
- J Lund
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway;
| | - A D Hafstad
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - N T Boardman
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - L Rossvoll
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - N P Rolim
- K. G. Jebsen Center of Exercise in Medicine, Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology and Saint Olavs Hospital, Trondheim University Hospital, Trondheim, Norway; and
| | - M S Ahmed
- Institute for Surgical Research, Department of Cardiology, Center for Heart Failure Research, Oslo University Hospital-Rikshospitalet, University of Oslo, Oslo, Norway
| | - G Florholmen
- Institute for Surgical Research, Department of Cardiology, Center for Heart Failure Research, Oslo University Hospital-Rikshospitalet, University of Oslo, Oslo, Norway
| | - H Attramadal
- Institute for Surgical Research, Department of Cardiology, Center for Heart Failure Research, Oslo University Hospital-Rikshospitalet, University of Oslo, Oslo, Norway
| | - U Wisløff
- K. G. Jebsen Center of Exercise in Medicine, Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology and Saint Olavs Hospital, Trondheim University Hospital, Trondheim, Norway; and
| | - T S Larsen
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - E Aasum
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| |
Collapse
|
4
|
Boardman NT, Aronsen JM, Louch WE, Sjaastad I, Willoch F, Christensen G, Sejersted O, Aasum E. Impaired left ventricular mechanical and energetic function in mice after cardiomyocyte-specific excision of Serca2. Am J Physiol Heart Circ Physiol 2014; 306:H1018-24. [PMID: 24486508 DOI: 10.1152/ajpheart.00741.2013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sarco(endo)plasmic reticulum Ca2+ -ATPase (SERCA)2 transports Ca2+ from the cytosol into the sarcoplasmic reticulum of cardiomyocytes and is essential for maintaining myocardial Ca2+ handling and thus the mechanical function of the heart. SERCA2 is a major ATP consumer in excitation-contraction coupling but is regarded to contribute to energetically efficient Ca2+ handling in the cardiomyocyte. Previous studies using cardiomyocyte-specific SERCA2 knockout (KO) mice have demonstrated that decreased SERCA2 activity reduces the Ca2+ transient amplitude and induces compensatory Ca2+ transport mechanisms that may lead to more inefficient Ca2+ transport. In this study, we examined the relationship between left ventricular (LV) function and myocardial O2 consumption (MVo2) in ex vivo hearts from SERCA2 KO mice to directly measure how SERCA2 elimination influences mechanical and energetic features of the heart. Ex vivo hearts from SERCA2 KO hearts developed mechanical dysfunction at 4 wk and demonstrated virtually no working capacity at 7 wk. In accordance with the reported reduction in Ca2+ transient amplitude in cardiomyocytes from SERCA2 KO mice, work-independent MVo2 was decreased due to a reduced energy cost of excitation-contraction coupling. As these hearts also showed a marked impairment in the efficiency of chemomechanical energy transduction (contractile efficiency, i.e, work-dependent MVo2), hearts from SERCA2 KO mice were found to be mechanically inefficient. This ex vivo evaluation of mechanical and energetic function in hearts from SERCA2 KO mice brings together findings from previous experimental and mathematical modeling-based studies and demonstrates that reduced SERCA2 activity not only leads to mechanical dysfunction but also to energetic dysfunction.
Collapse
Affiliation(s)
- N T Boardman
- Cardiovascular Research Group, Department of Medical Biology, Faculty of Health Sciences, UiT The Artic University of Norway, Tromsø, Norway
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Masoud WG, Ussher JR, Wang W, Jaswal JS, Wagg CS, Dyck JR, Lygate CA, Neubauer S, Clanachan AS, Lopaschuk GD. Failing mouse hearts utilize energy inefficiently and benefit from improved coupling of glycolysis and glucose oxidation. Cardiovasc Res 2013; 101:30-8. [DOI: 10.1093/cvr/cvt216] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
6
|
NHE-1 blockade reversed changes in calcium transient in myocardial slices from isoproterenol-induced hypertrophied rat left ventricle. Biochem Biophys Res Commun 2012; 419:431-5. [DOI: 10.1016/j.bbrc.2012.02.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 02/07/2012] [Indexed: 11/24/2022]
|
7
|
Shibata M, Takeshita D, Obata K, Mitsuyama S, Ito H, Zhang GX, Takaki M. NHE-1 participates in isoproterenol-induced downregulation of SERCA2a and development of cardiac remodeling in rat hearts. Am J Physiol Heart Circ Physiol 2011; 301:H2154-60. [DOI: 10.1152/ajpheart.00483.2011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Impaired Ca2+ handling is one of the main characteristics in heart failure patients. Recently, we reported abnormal expressions of Ca2+-handling proteins in isoproterenol (ISO)-induced hypertrophied rat hearts. On the other hand, Na+/H+ exchanger (NHE)-1 inhibitor has been demonstrated to exert beneficial effects in ischemic-reperfusion injury and in the development of cardiac remodeling. The aims of the present study are to investigate the role of NHE-1 on Ca2+ handling and development of cardiac hypertrophy in ISO-infused rats. Male Wistar rats were randomly divided into vehicle [control (CTL)] and ISO groups without or with pretreatment with a selective NHE-1 inhibitor, BIIB-723. ISO infusion for 1 wk significantly increased the ratios of heart to body weight and left ventricle (LV) to body weight and collagen accumulation. All of these increases were antagonized by coadministration with BIIB-723. The ISO-induced significant increase in LV wall thickness was suppressed significantly ( P < 0.05) by BIIB-723. ISO-induced decreases in cardiac stroke volume and a total mechanical energy per beat index, systolic pressure-volume area at midrange LV volume, were normalized by BIIB-723. The markedly higher expression of NHE-1 protein in the ISO group than that in CTL group was suppressed ( P < 0.05) by BIIB-723. Surprisingly, ISO induced downregulation of the important Ca2+-handling protein sarcoplasmic reticulum Ca2+-ATPase 2a, the expression of which was also normalized by BIIB-723 without changes in phosphorylated phospholamban (PLB)/PLB expression. We conclude that NHE-1 contributes to ISO-induced abnormal Ca2+ handling associated with cardiac hypertrophy. Inhibition of NHE-1 ameliorates cardiac Ca2+-handling impairment and prevents the development of cardiac dysfunction in ISO-infused rats.
Collapse
Affiliation(s)
- Munetaka Shibata
- Department of Physiology II, Nara Medical University School of Medicine, Kashihara, Nara, Japan; and
| | - Daisuke Takeshita
- Department of Physiology II, Nara Medical University School of Medicine, Kashihara, Nara, Japan; and
| | - Koji Obata
- Department of Physiology II, Nara Medical University School of Medicine, Kashihara, Nara, Japan; and
| | - Shinichi Mitsuyama
- Department of Physiology II, Nara Medical University School of Medicine, Kashihara, Nara, Japan; and
| | - Haruo Ito
- Department of Physiology II, Nara Medical University School of Medicine, Kashihara, Nara, Japan; and
| | - Guo-Xing Zhang
- Department of Physiology II, Nara Medical University School of Medicine, Kashihara, Nara, Japan; and
- Department of Physiology, Medical College of Soochow University, Suzhou, Peoples Republic of China
| | - Miyako Takaki
- Department of Physiology II, Nara Medical University School of Medicine, Kashihara, Nara, Japan; and
| |
Collapse
|
8
|
Nakajima-Takenaka C, Zhang GX, Obata K, Tohne K, Matsuyoshi H, Nagai Y, Nishiyama A, Takaki M. Left ventricular function of isoproterenol-induced hypertrophied rat hearts perfused with blood: mechanical work and energetics. Am J Physiol Heart Circ Physiol 2009; 297:H1736-43. [PMID: 19734357 DOI: 10.1152/ajpheart.00672.2009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated left ventricular (LV) mechanical work and energetics in the cross-circulated (blood-perfused) isoproterenol [Iso 1.2 mg x kg(-1).day(-1) for 3 days (Iso3) or 7 days (Iso7)]-induced hypertrophied rat heart preparation under isovolumic contraction-relaxation. We evaluated pressure-time curves per beat, end-systolic pressure-volume and end-diastolic pressure-volume relations, and myocardial O(2) consumption per beat (Vo(2))-systolic pressure-volume area (PVA; a total mechanical energy per beat) linear relations at 240 beats/min, because Iso-induced hypertrophied hearts failed to completely relax at 300 beats/min. The LV relaxation rate at 240 beats/min in Iso-induced hypertrophied hearts was significantly slower than that in control hearts [saline 24 microl/day for 3 and 7 days (Sa)] with unchanged contraction rate. The Vo(2)-intercepts (composed of basal metabolism and Ca(2+) cycling energy consumption in excitation-contraction coupling) of Vo(2)-PVA linear relations were unchanged associated with their unchanged slopes in Sa, Iso3, and Iso7 groups. The oxygen costs of LV contractility were also unchanged in all three groups. The amounts of expression of sarcoplasmic reticulum Ca(2+)-ATPase, phospholamban (PLB), phosphorylated-Ser(16) PLB, phospholemman, and Na(+)-K(+)-ATPase are significantly decreased in Iso3 and Iso7 groups, although the amount of expression of NCX1 is unchanged in all three groups. Furthermore, the marked collagen production (types I and III) was observed in Iso3 and Iso7 groups. These results suggested the possibility that lowering the heart rate was beneficial to improve mechanical work and energetics in isoproterenol-induced hypertrophied rat hearts, although LV relaxation rate was slower than in normal hearts.
Collapse
|
9
|
Takeshita D, Nakajima-Takenaka C, Shimizu J, Hattori H, Nakashima T, Kikuta A, Matsuyoshi H, Takaki M. Effects of formaldehyde on cardiovascular system in in situ rat hearts. Basic Clin Pharmacol Toxicol 2009; 105:271-80. [PMID: 19558560 DOI: 10.1111/j.1742-7843.2009.00442.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The aim of the present study was to examine the effects of formaldehyde solution on rat left ventricular function and compare it with those in hypertrophic hearts treated with isoproterenol by pressure-volume measurements with the catheter method. After 20-30 min. of intravenous infusion of 3.7% formaldehyde solution (FA) at 10 μl (3.7 mg)/kg/min, normal and hypertrophic hearts showed significant decreases in left ventricle end-systolic pressure (ESP), heart rate and cardiac output per minute, indicating an acute pumping failure. Hypertrophic hearts showed significantly smaller ESP, stroke volumes and cardiac output than those in normal hearts. Systolic pressure-volume area at midrange left ventricular volume (PVA(mLVV) : a mechanical work capability index) was significantly smaller than that in normal hearts and per cent of mean PVA(mLVV) versus pre-infusion mean value in hypertrophic hearts was significantly decreased compared to normal hearts 30 min. after FA infusion. The marked decrease in pH, base excess and no changes in PaO₂ and PaCO₂ suggest metabolic acidosis. The correction of metabolic acidosis with 9% NaHCO₃ did not influence on the acute pumping failure, indicating that metabolic acidosis did not cause it. Ultrastructural observations revealed marked dilation of the sarcoplasmic reticulum with intact sarcolemmal membranes and no disintegration of muscle myofibrils. Ryanodine receptors and calcium (Ca²⁺) pumps (SERCA2A) located in the sarcoplasmic reticulum have major roles in the cytosolic Ca²⁺ handling. Taken together, acute pumping failure by FA may derive from the impairment of Ca²⁺ handling in the cardiac excitation-contraction coupling.
Collapse
Affiliation(s)
- Daisuke Takeshita
- Department of Physiology II, Nara Medical University, Kashihara, Japan
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Takewa Y, Chemaly ER, Takaki M, Liang LF, Jin H, Karakikes I, Morel C, Taenaka Y, Tatsumi E, Hajjar RJ. Mechanical work and energetic analysis of eccentric cardiac remodeling in a volume overload heart failure in rats. Am J Physiol Heart Circ Physiol 2009; 296:H1117-24. [PMID: 19201995 DOI: 10.1152/ajpheart.01120.2008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Eccentric cardiac remodeling seen in dilated cardiomyopathy or regurgitant valvular disease is a well-known process of heart failure progression, but its mechanoenergetic profile has not been yet established. We made a volume overload (VO) heart failure model in rats and for the first time investigated left ventricular (LV) mechanical work and energetics in cross-circulated whole heart preparations. Laparotomy was performed in 14 Wistar male rats, and abdominal aortic-inferior vena caval shunt was created in seven rats (VO group). Another seven rats underwent a sham operation without functional shunt (Sham group). LV dimensions changes were followed with weekly transthoracic echocardiography. Three months after surgery, we measured LV pressure and volume and myocardial O(2) consumption in isolated heart cross circulation. LV internal dimensions in both systolic and diastolic phases were significantly increased in the VO group versus the Sham group (P < 0.05). LV pressure was markedly decreased in the VO group versus in the Sham group (P < 0.05). LV end-systolic pressure-volume relation shifted downward, and myocardial O(2) consumption related to Ca(2+) handling significantly decreased. The contractile response to Ca(2+) infusion was attenuated. Nevertheless, the increase in Ca(2+) handling-related O(2) consumption per unit change in LV contractility in the VO group was significantly higher than that in the Sham group (P < 0.05). The levels of sarco(endo)plasmic reticulum Ca(2+)-ATPase 2a protein were reduced in the VO group (P < 0.01). In conclusion, VO failing rat hearts had a character of marked contractile dysfunction accompanied with less efficient energy utilization in the Ca(2+) handling processes. These results suggest that restoring Ca(2+) handling in excitation-contraction coupling would improve the contractility of the myocardium after eccentric cardiac remodeling.
Collapse
Affiliation(s)
- Yoshiaki Takewa
- Cardiovascular Research Center, Mount Sinai School of Medicine, One Gustave Levy Place, Box 1030, New York, NY 10029, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|