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Kumar RA, Hahn D, Kelley RC, Muscato DR, Shamoun A, Curbelo-Bermudez N, Butler WG, Yegorova S, Ryan TE, Ferreira LF. Skeletal muscle Nox4 knockout prevents and Nox2 knockout blunts loss of maximal diaphragm force in mice with heart failure with reduced ejection fraction. Free Radic Biol Med 2023; 194:23-32. [PMID: 36436728 PMCID: PMC10191720 DOI: 10.1016/j.freeradbiomed.2022.11.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 11/14/2022] [Accepted: 11/14/2022] [Indexed: 11/27/2022]
Abstract
Patients with heart failure with reduced ejection fraction (HFrEF) experience diaphragm weakness that contributes to the primary disease symptoms of fatigue, dyspnea, and exercise intolerance. Weakness in the diaphragm is related to excessive production of reactive oxygen species (ROS), but the exact source of ROS remains unknown. NAD(P)H Oxidases (Nox), particularly the Nox2 and 4 isoforms, are important sources of ROS within skeletal muscle that contribute to optimal cell function. There are reports of increased Nox activity in the diaphragm of patients and animal models of HFrEF, implicating these complexes as possible sources of diaphragm dysfunction in HFrEF. To investigate the role of these proteins on diaphragm weakness in HFrEF, we generated inducible skeletal muscle specific knockouts of Nox2 or Nox4 using the Cre-Lox system and assessed diaphragm function in a mouse model of HFrEF induced by myocardial infarction. Diaphragm maximal specific force measured in vitro was depressed by ∼20% with HFrEF. Skeletal muscle knockout of Nox4 provided full protection against the loss of maximal force (p < 0.01), while the knockout of Nox2 provided partial protection (7% depression, p < 0.01). Knockout of Nox2 from skeletal myofibers improved survival from 50 to 80% following myocardial infarction (p = 0.026). Our findings show an important role for skeletal muscle NAD(P)H Oxidases contributing to loss of diaphragm maximal force in HFrEF, along with systemic pathophysiological responses following myocardial infarction.
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Affiliation(s)
- Ravi A Kumar
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA; King's College London British Heart Foundation Centre of Excellence, School of Cardiovascular Medicine & Sciences, London, United Kingdom
| | - Dongwoo Hahn
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA; Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN, USA
| | - Rachel C Kelley
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA; Endocrine Society, Washington, D.C, USA
| | - Derek R Muscato
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Alex Shamoun
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Nuria Curbelo-Bermudez
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - W Greyson Butler
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Svetlana Yegorova
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Terence E Ryan
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA
| | - Leonardo F Ferreira
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.
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Noonan AM, Oxland TR, Brown SHM. Investigating the active contractile function of the rat paraspinal muscles reveals unique cross-bridge kinetics in the multifidus. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2022; 31:783-791. [PMID: 35089421 DOI: 10.1007/s00586-022-07120-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 11/17/2021] [Accepted: 01/13/2022] [Indexed: 11/24/2022]
Abstract
PURPOSE Various aspects of paraspinal muscle anatomy, biology, and histology have been studied; however, information on paraspinal muscle contractile function is almost nonexistent, thus hindering functional interpretation of these muscles in healthy individuals and those with low back disorders. The aim of this study was to measure and compare the contractile function and force-sarcomere length properties of muscle fibers from the multifidus (MULT) and erector spinae (ES) as well as a commonly studied lower limb muscle (Extensor digitorum longus (EDL)) in the rat. METHODS Single muscle fibers (n = 77 total from 6 animals) were isolated from each of the muscles and tested to determine their active contractile function; all fibers used in the analyses were type IIB. RESULTS There were no significant differences between muscles for specific force (sFo) (p = 0.11), active modulus (p = 0.63), average optimal sarcomere length (p = 0.27) or unloaded shortening velocity (Vo) (p = 0.69). However, there was a significant difference in the rate of force redevelopment (ktr) between muscles (p = < 0.0001), with MULT being significantly faster than both the EDL (p = < 0.0001) and ES (p = 0.0001) and no difference between the EDL and ES (p = 0.41). CONCLUSIONS This finding suggests that multifidus has faster cross-bridge turnover kinetics when compared to other muscles (ES and EDL) when matched for fiber type. Whether the faster cross-bridge kinetics translate to a functionally significant difference in whole muscle performance needs to be studied further.
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Affiliation(s)
- Alex M Noonan
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Thomas R Oxland
- Department of Orthopaedics, The University of British Columbia, Vancouver, Canada
- International Collaboration on Repair Discoveries (ICORD), The University of British Columbia, Vancouver, Canada
- Department of Mechanical Engineering, The University of British Columbia, Vancouver, Canada
| | - Stephen H M Brown
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada.
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Böttner J, Werner S, Adams V, Knauth S, Kricke A, Thiele H, Büttner P. Structural and functional alterations in heart and skeletal muscle following severe TAC in mice: impact of moderate exercise training. Biol Res 2021; 54:31. [PMID: 34538250 PMCID: PMC8451113 DOI: 10.1186/s40659-021-00354-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/30/2021] [Indexed: 11/10/2022] Open
Abstract
Background Heart failure (HF) is the leading cause of death in western countries. Cardiac dysfunction is accompanied by skeletal alterations resulting in muscle weakness and fatigue. Exercise is an accepted interventional approach correcting cardiac and skeletal dysfunction, thereby improving mortality, re-hospitalization and quality of life. Animal models are used to characterize underpinning mechanisms. Transverse aortic constriction (TAC) results in cardiac pressure overload and finally HF. Whether exercise training improves cardiac remodeling and peripheral cachexia in the TAC mouse model was not analyzed yet. In this study, 2 weeks post TAC animals were randomized into two groups either performing a moderate exercise program (five times per week at 60% VO2 max for 40 min for a total of 8 weeks) or staying sedentary. Results In both TAC groups HF characteristics reduced ejection fraction (− 15% compared to sham, p < 0.001), cardiac remodeling (+ 22.5% cardiomyocyte cross sectional area compared to sham; p < 0.001) and coronary artery congestion (+ 34% diameter compared to sham; p = 0.008) were observed. Unexpectedly, peripheral cachexia was not detected. Furthermore, compared to sedentary group animals from the exercise group showed aggravated HF symptoms [heart area + 9% (p = 0.026), heart circumference + 7% (p = 0.002), right ventricular wall thickness − 30% (p = 0.003)] while muscle parameters were unchanged [Musculus soleus fiber diameter (p = 0.55), Musculus extensor digitorum longus contraction force (p = 0.90)]. Conclusion The severe TAC model is inappropriate to study moderate exercise effects in HF with respect to cardiac and skeletal muscle improvements. Further, the phenotype induced by different TAC procedures should be well documented and taken into account when planning experiments.
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Affiliation(s)
- Julia Böttner
- Department of Cardiology, Heart Center Leipzig at University of Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany.
| | - Sarah Werner
- Department of Cardiology, Heart Center Leipzig at University of Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - Volker Adams
- Laboratory of Molecular and Experimental Cardiology, TU Dresden, Heart Center Dresden, Dresden, Germany
| | - Sarah Knauth
- Department of Cardiology, Heart Center Leipzig at University of Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - Angela Kricke
- Department of Cardiology, Heart Center Leipzig at University of Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - Holger Thiele
- Department of Cardiology, Heart Center Leipzig at University of Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
| | - Petra Büttner
- Department of Cardiology, Heart Center Leipzig at University of Leipzig, Strümpellstr. 39, 04289, Leipzig, Germany
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Paraspinal Muscle Contractile Function is Impaired in the ENT1-deficient Mouse Model of Progressive Spine Pathology. Spine (Phila Pa 1976) 2021; 46:E710-E718. [PMID: 33332787 DOI: 10.1097/brs.0000000000003882] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Basic science study of the relationship between spine pathology and the contractile ability of the surrounding muscles. OBJECTIVE The aim of this study was to investigate single muscle fiber contractile function in a model of progressive spine mineralization (ENT1-/- mice). SUMMARY OF BACKGROUND DATA Altered muscle structure and function have been associated with various spine pathologies; however, studies to date have provided limited insight into the fundamental ability of spine muscles to actively contract and generate force, and how this may change in response to spine pathology. METHODS Experiments were performed on two groups (ENT1-/- [KO] and ENT1+/+ [WT]) of mice at 8 months of age (n = 12 mice/group). Single muscle fibers were isolated from lumbar multifidus and erector spinae, as well as tibialis anterior (a non-spine-related control) and tested to determine their active contractile characteristics. RESULTS The multifidus demonstrated decreases in specific force (type IIax fibers: 36% decrease; type IIb fibers: 29% decrease), active modulus (type IIax: 35% decrease; type IIb: 30% decrease), and unloaded shortening velocity (Vo) (type IIax: 31% decrease) in the ENT1-/- group when compared to WT controls. The erector spinae specific force was reduced in the ENT1-/- mice when compared to WT (type IIax: 29% decrease), but active modulus and Vo were unchanged. There were no differences in any of the active contractile properties of the lower limb TA muscle, validating that impairments observed in the spine muscles were specific to the underlying spine pathology and not the global loss of ENT1. CONCLUSION These results provide the first direct evidence of cellular level impairments in the active contractile force generating properties of spine muscles in response to chronic spine pathology.Level of Evidence: N/A.
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Cabrera-Aguilera I, Falcones B, Calvo-Fernández A, Benito B, Barreiro E, Gea J, Farré R, Almendros I, Farré N. The conventional isoproterenol-induced heart failure model does not consistently mimic the diaphragmatic dysfunction observed in patients. PLoS One 2020; 15:e0236923. [PMID: 32730329 PMCID: PMC7392250 DOI: 10.1371/journal.pone.0236923] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 07/16/2020] [Indexed: 11/25/2022] Open
Abstract
Heart failure (HF) impairs diaphragm function. Animal models realistically mimicking HF should feature both the cardiac alterations and the diaphragmatic dysfunction characterizing this disease. The isoproterenol-induced HF model is widely used, but whether it presents diaphragmatic dysfunction is unknown. However, indirect data from research in other fields suggest that isoproterenol could increase diaphragm function. The aim of this study was to test the hypothesis that the widespread rodent model of isoproterenol-induced HF results in increased diaphragmatic contractility. Forty C57BL/6J male mice were randomized into 2 groups: HF and healthy controls. After 30 days of isoproterenol infusion to establish HF, in vivo diaphragmatic excursion and ex vivo isolated diaphragm contractibility were measured. As compared with healthy controls, mice with isoproterenol-induced HF showed the expected changes in structural and functional echocardiographic parameters and lung edema. isoproterenol-induced HF increased in vivo diaphragm excursion (by ≈30%, p<0.01) and increased by ≈50% both ex vivo peak specific force (p<0.05) and tetanic force (p<0.05) at almost all 10–100 Hz frequencies (p<0.05), with reduced fatigue resistance (p<0.01) when compared with healthy controls. Expression of myosin genes encoding the main muscle fiber types revealed that Myh4 was higher in isoproterenol-induced HF than in healthy controls (p<0.05), suggesting greater distribution of type IIb fibers. These results show that the conventional isoproterenol-induced HF model increases diaphragm contraction, a finding contrary to what is observed in patients with HF. Therefore, this specific model seems limited for translational an integrative HF research, especially when cardio-respiratory interactions are investigated.
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Affiliation(s)
- Ignacio Cabrera-Aguilera
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
- Heart Diseases Biomedical Research Group, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain
- Department of Human Movement Sciences, School of Kinesiology, Faculty of Health Sciences, Universidad de Talca, Talca, Chile
| | - Bryan Falcones
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
| | - Alicia Calvo-Fernández
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Heart Failure Unit, Department of Cardiology, Hospital del Mar, Barcelona, Spain
| | - Begoña Benito
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Cardiology Department, Hospital Universitari Vall d'Hebron, Vall d'Hebron Research Institute (VHIR), Barcelona, Spain
- CIBER de Enfermedades Cardiovasculares, Madrid, Spain
| | - Esther Barreiro
- Respiratory Department, Hospital del Mar and Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
- Health and Experimental Sciences Department (CEXS), Universitat Pompeu Fabra, Barcelona, Spain
- CIBER de Enfermedades Respiratorias, Madrid, Spain
| | - Joaquim Gea
- Respiratory Department, Hospital del Mar and Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
- Health and Experimental Sciences Department (CEXS), Universitat Pompeu Fabra, Barcelona, Spain
- CIBER de Enfermedades Respiratorias, Madrid, Spain
| | - Ramon Farré
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
- CIBER de Enfermedades Respiratorias, Madrid, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | - Isaac Almendros
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, Barcelona, Spain
- CIBER de Enfermedades Respiratorias, Madrid, Spain
- Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona, Spain
| | - Núria Farré
- Heart Diseases Biomedical Research Group, IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Heart Failure Unit, Department of Cardiology, Hospital del Mar, Barcelona, Spain
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Diaphragm weakness and proteomics (global and redox) modifications in heart failure with reduced ejection fraction in rats. J Mol Cell Cardiol 2020; 139:238-249. [PMID: 32035137 DOI: 10.1016/j.yjmcc.2020.02.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/02/2020] [Accepted: 02/03/2020] [Indexed: 12/16/2022]
Abstract
Inspiratory dysfunction occurs in patients with heart failure with reduced ejection fraction (HFrEF) in a manner that depends on disease severity and by mechanisms that are not fully understood. In the current study, we tested whether HFrEF effects on diaphragm (inspiratory muscle) depend on disease severity and examined putative mechanisms for diaphragm abnormalities via global and redox proteomics. We allocated male rats into Sham, moderate (mHFrEF), or severe HFrEF (sHFrEF) induced by myocardial infarction and examined the diaphragm muscle. Both mHFrEF and sHFrEF caused atrophy in type IIa and IIb/x fibers. Maximal and twitch specific forces (N/cm2) were decreased by 19 ± 10% and 28 ± 13%, respectively, in sHFrEF (p < .05), but not in mHFrEF. Global proteomics revealed upregulation of sarcomeric proteins and downregulation of ribosomal and glucose metabolism proteins in sHFrEF. Redox proteomics showed that sHFrEF increased reversibly oxidized cysteine in cytoskeletal and thin filament proteins and methionine in skeletal muscle α-actin (range 0.5 to 3.3-fold; p < .05). In conclusion, fiber atrophy plus contractile dysfunction caused diaphragm weakness in HFrEF. Decreased ribosomal proteins and heighted reversible oxidation of protein thiols are candidate mechanisms for atrophy or anabolic resistance as well as loss of specific force in sHFrEF.
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Ding Y, Lyons SA, Scott GR, Gillis TE. Characterizing the influence of chronic hypobaric hypoxia on diaphragmatic myofilament contractile function and phosphorylation in high-altitude deer mice and low-altitude white-footed mice. J Comp Physiol B 2019; 189:489-499. [PMID: 31278612 DOI: 10.1007/s00360-019-01224-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 06/06/2019] [Accepted: 06/24/2019] [Indexed: 11/27/2022]
Abstract
Deer mice, Peromyscusmaniculatus, live at high altitudes where limited O2 represents a challenge to maintaining oxygen delivery to tissues. Previous work has demonstrated that hypoxia acclimation of deer mice and low altitude white-footed mice (P. leucopus) increases the force generating capacity of the diaphragm. The mechanism behind this improved contractile function is not known. Within myocytes, the myofilament plays a critical role in setting the rate and level of force production, and its ability to generate force can change in response to changes in physiological conditions. In the current study, we examined how chronic hypobaric hypoxia exposure of deer mice and white-footed mice influences the Ca2+ activation of force generation by skinned diaphragmatic myofilaments, and the phosphorylation of myofilament proteins. Results demonstrate that myofilament force production, and the Ca2+ sensitivity of force generation, were not impacted by acclimation to hypobaric hypoxia, and did not differ between preparations from the two species. The cooperativity of the force-pCa relationship, and the maximal rate of force generation were also the same in the preparations from both species, and not impacted by acclimation. Finally, the relative phosphorylation of TnT, and MLC was lower in deer mice than white-footed mice, but was not affected by acclimation. These results indicate that species differences in diaphragm function, and the increase in force production with hypoxia acclimation, are not due to differences, or changes, in myofilament function. However, it appears that diaphragmatic myofilament function in these species is not affected by chronic hypobaric hypoxia exposure.
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Affiliation(s)
- Y Ding
- Department of Integrative Biology, University of Guelph, Guelph, ON, N1G-2W1, Canada
| | - S A Lyons
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - G R Scott
- Department of Biology, McMaster University, Hamilton, ON, Canada
| | - Todd E Gillis
- Department of Integrative Biology, University of Guelph, Guelph, ON, N1G-2W1, Canada.
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Dawson NJ, Lyons SA, Henry DA, Scott GR. Effects of chronic hypoxia on diaphragm function in deer mice native to high altitude. Acta Physiol (Oxf) 2018; 223:e13030. [PMID: 29316265 DOI: 10.1111/apha.13030] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 12/08/2017] [Accepted: 12/31/2017] [Indexed: 12/22/2022]
Abstract
AIM We examined the effects of chronic hypoxia on diaphragm function in high- and low-altitude populations of Peromyscus mice. METHODS Deer mice (P. maniculatus) native to high altitude and congeneric mice native to low altitude (P. leucopus) were born and raised in captivity to adulthood and were acclimated to normoxia or hypobaric hypoxia (12 or 9 kPa, simulating hypoxia at 4300 and 7000 m) for 6-8 weeks. We then measured indices of mitochondrial respiration capacity, force production, and fatigue resistance in the diaphragm. RESULTS Mitochondrial respiratory capacities (assessed using permeabilized fibres with single or multiple inputs to the electron transport system), citrate synthase activity (a marker of mitochondrial volume), twitch force production, and muscle fatigue resistance increased after exposure to chronic hypoxia in both populations. These changes were not well explained by variation in the fibre-type composition of the muscle. However, there were several differences in diaphragm function in high-altitude mice compared to low-altitude mice. Exposure to a deeper level of hypoxia (9 kPa vs 12 kPa) was needed to elicit increases in mitochondrial respiration rates in highlanders. Chronic hypoxia did not increase the emission of reactive oxygen species from permeabilized fibres in highlanders, in contrast to the pronounced increases that occurred in lowlanders. In general, the diaphragm of high-altitude mice had greater capillary length densities, produced less force in response to stimulation and had shorter relaxation times. The latter was associated with higher activity of sarcoplasmic reticulum Ca2+ -ATPase (SERCA) activity in the diaphragm of high-altitude mice. CONCLUSION Overall, our work suggests that exposure to chronic hypoxia increases the capacities for mitochondrial respiration, force production and fatigue resistance of the diaphragm. However, many of these effects are opposed by evolved changes in diaphragm function in high-altitude natives, such that highlanders in chronic hypoxia maintain similar diaphragm function to lowlanders in sea level conditions.
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Affiliation(s)
- N. J. Dawson
- Department of Biology; McMaster University; Hamilton ON Canada
| | - S. A. Lyons
- Department of Biology; McMaster University; Hamilton ON Canada
| | - D. A. Henry
- Department of Biology; McMaster University; Hamilton ON Canada
| | - G. R. Scott
- Department of Biology; McMaster University; Hamilton ON Canada
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Foster AJ, Platt MJ, Huber JS, Eadie AL, Arkell AM, Romanova N, Wright DC, Gillis TE, Murrant CL, Brunt KR, Simpson JA. Central-acting therapeutics alleviate respiratory weakness caused by heart failure-induced ventilatory overdrive. Sci Transl Med 2018; 9:9/390/eaag1303. [PMID: 28515334 DOI: 10.1126/scitranslmed.aag1303] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 03/13/2017] [Indexed: 12/22/2022]
Abstract
Diaphragmatic weakness is a feature of heart failure (HF) associated with dyspnea and exertional fatigue. Most studies have focused on advanced stages of HF, leaving the cause unresolved. The long-standing theory is that pulmonary edema imposes a mechanical stress, resulting in diaphragmatic remodeling, but stable HF patients rarely exhibit pulmonary edema. We investigated how diaphragmatic weakness develops in two mouse models of pressure overload-induced HF. As in HF patients, both models had increased eupneic respiratory pressures and ventilatory drive. Despite the absence of pulmonary edema, diaphragmatic strength progressively declined during pressure overload; this decline correlated with a reduction in diaphragm cross-sectional area and preceded evidence of muscle weakness. We uncovered a functional codependence between angiotensin II and β-adrenergic (β-ADR) signaling, which increased ventilatory drive. Chronic overdrive was associated with increased PERK (double-stranded RNA-activated protein kinase R-like ER kinase) expression and phosphorylation of EIF2α (eukaryotic translation initiation factor 2α), which inhibits protein synthesis. Inhibition of β-ADR signaling after application of pressure overload normalized diaphragm strength, Perk expression, EIF2α phosphorylation, and diaphragmatic cross-sectional area. Only drugs that were able to penetrate the blood-brain barrier were effective in treating ventilatory overdrive and preventing diaphragmatic atrophy. These data provide insight into why similar drugs have different benefits on mortality and symptomatology, despite comparable cardiovascular effects.
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Affiliation(s)
- Andrew J Foster
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Mathew J Platt
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Jason S Huber
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Ashley L Eadie
- Department of Pharmacology, Dalhousie Medicine, Saint John, New Brunswick E2L 4L5, Canada
| | - Alicia M Arkell
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Nadya Romanova
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - David C Wright
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Todd E Gillis
- Department of Integrative Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Coral L Murrant
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Keith R Brunt
- Department of Pharmacology, Dalhousie Medicine, Saint John, New Brunswick E2L 4L5, Canada.
| | - Jeremy A Simpson
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
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Lindsey ML, Kassiri Z, Virag JAI, de Castro Brás LE, Scherrer-Crosbie M. Guidelines for measuring cardiac physiology in mice. Am J Physiol Heart Circ Physiol 2018; 314:H733-H752. [PMID: 29351456 PMCID: PMC5966769 DOI: 10.1152/ajpheart.00339.2017] [Citation(s) in RCA: 215] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Cardiovascular disease is a leading cause of death, and translational research is needed to understand better mechanisms whereby the left ventricle responds to injury. Mouse models of heart disease have provided valuable insights into mechanisms that occur during cardiac aging and in response to a variety of pathologies. The assessment of cardiovascular physiological responses to injury or insult is an important and necessary component of this research. With increasing consideration for rigor and reproducibility, the goal of this guidelines review is to provide best-practice information regarding how to measure accurately cardiac physiology in animal models. In this article, we define guidelines for the measurement of cardiac physiology in mice, as the most commonly used animal model in cardiovascular research. Listen to this article’s corresponding podcast at http://ajpheart.podbean.com/e/guidelines-for-measuring-cardiac-physiology-in-mice/.
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Affiliation(s)
- Merry L Lindsey
- Department of Physiology and Biophysics, Mississippi Center for Heart Research, University of Mississippi Medical Center , Jackson, Mississippi.,Research Service, G.V. (Sonny) Montgomery Veterans Affairs Medical Center , Jackson, Mississippi
| | - Zamaneh Kassiri
- Department of Physiology, Cardiovascular Research Centre, Mazankowski Alberta Heart Institute, University of Alberta , Edmonton, Alberta , Canada
| | - Jitka A I Virag
- Department of Physiology, Brody School of Medicine, East Carolina University , Greenville, North Carolina
| | - Lisandra E de Castro Brás
- Department of Physiology, Brody School of Medicine, East Carolina University , Greenville, North Carolina
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Physiological and functional failure in chronic obstructive pulmonary disease, congestive heart failure and cancer: a debilitating intersection of sarcopenia, cachexia and breathlessness. Curr Opin Support Palliat Care 2016; 10:236-41. [DOI: 10.1097/spc.0000000000000222] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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