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Lin X, Hu Z, Tang L, Zhan Y. Association between frailty index and epigenetic aging acceleration in older adults: Evidence from the health and retirement study. Exp Gerontol 2025; 205:112765. [PMID: 40286999 DOI: 10.1016/j.exger.2025.112765] [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: 09/17/2024] [Revised: 04/06/2025] [Accepted: 04/23/2025] [Indexed: 04/29/2025]
Abstract
BACKGOUND This study aimed to examine the associations between the frailty index and four epigenetic aging acceleration (EAA) estimators in cross-sectional and longitudinal settings. METHODS The frailty index in the older adults was measured according to a cumulative health-deficit model. Four different epigenetic age measures (Hannum, PhenoAge, GrimAge, and DunedinPoAm38) were regressed against chronological age, and the resulting standardized residuals were indicative of EAA. The longitudinal relationship between EAA at baseline and changes in the frailty index during the 4-year follow-up were examined using a mixed linear model. RESULTS A single standard deviation (SD) increment in the frailty index was associated with a faster EAA, as indicated by the four clocks in Hannum (b = 0.057; P = 0.015), PhenoAge (b = 0.096; P < 0.001), GrimAge (b = 0.120; P < 0.001), and DunedinPoAm38 (b = 0.062; P = 0.002) in the fully adjusted model. A 1-SD increment in the GrimAge EAA was associated with a 0.003 frailty index increase (b = 0.003; P = 0.002). A 1-SD increment in DunedinPoAm38 EAA was associated with a 0.002 frailty index increase (b = 0.002; P = 0.009). CONCLUSIONS The frailty index was cross-sectionally associated with EAA, while only GrimAge and DunedinPoAm38 EAA predicted changes in the frailty index. More research is needed to understand the interplay between pathways.
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Affiliation(s)
- Xuhui Lin
- Department of Social Medicine and Health Management, Xiangya School of Public Health, Central South University, China
| | - Zhao Hu
- Department of Epidemiology, School of Public Health(Shen Zhen), Sun Yat-sen university, China.
| | - Lu Tang
- The seven Affiliation Hospital, Sun Yat-sen University, China
| | - Yiqiang Zhan
- Department of Epidemiology, School of Public Health(Shen Zhen), Sun Yat-sen university, China; Guangdong Engineering Technology Research Center of Nutrition Transformation, Sun Yat-sen University, Shenzhen, China; Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
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2
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Mangoni AA, Woodman RJ, Jarmuzewska EA. Pharmacokinetic and pharmacodynamic alterations in older people: what we know so far. Expert Opin Drug Metab Toxicol 2025:1-19. [PMID: 40338211 DOI: 10.1080/17425255.2025.2503848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2025] [Revised: 04/14/2025] [Accepted: 05/06/2025] [Indexed: 05/09/2025]
Abstract
INTRODUCTION Healthcare professionals face increasing challenges when managing older patients, a group characterized by significant interindividual variability in comorbidity patterns, homeostatic capacity, frailty status, cognitive function, and life expectancy. Complex therapeutic decisions may increase the risk of inappropriate polypharmacy, drug-drug, and drug-disease interactions in the context of age-associated pharmacokinetic and pharmacodynamic alterations, with consequent drug accumulation and toxicity. AREAS COVERED This state-of-the-art narrative review article summarizes and critically appraises the results of original research studies and reviews published in PubMed, Scopus, and Web of Science, from inception to 9 April 2025, on age-associated changes in critical organs and systems and relevant pharmacokinetic and pharmacodynamic alterations. It also discusses the emerging role of frailty and the gut microbiota in influencing such alterations and the potential utility of machine learning techniques in identifying new signals of drug efficacy and toxicity in older patients. EXPERT OPINION The available knowledge regarding specific age-associated pharmacokinetic and pharmacodynamic alterations applies to a limited number of drugs, some of which are not frequently prescribed in contemporary practice. Future studies investigating a wider range of drugs and their patterns of use will likely enhance therapeutic efficacy and minimize toxicity in the older patient population.
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Affiliation(s)
- Arduino A Mangoni
- Discipline of Clinical Pharmacology, College of Medicine and Public Health, Flinders University, Adelaide, Australia
- Department of Clinical Pharmacology, Flinders Medical Centre, Southern Adelaide Local Health Network, Adelaide, Australia
| | - Richard J Woodman
- Discipline of Biostatistics, College of Medicine and Public Health, Flinders University, Adelaide, Australia
| | - Elzbieta A Jarmuzewska
- Department of Internal Medicine, Polyclinic IRCCS, Ospedale Maggiore, University of Milan, Milan, Italy
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3
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Ringström N, Edling C, Nalesso G, Barallobre-Barreiro J, Jeevaratnam K. Mass spectrometry reveals age-dependent collagen decline in murine atria. Ann N Y Acad Sci 2025. [PMID: 40295212 DOI: 10.1111/nyas.15341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2025]
Abstract
The cardiac atrial extracellular matrix (ECM) is central to age-associated cardiac remodeling and subsequent decline in cardiac functioning. Despite this, the composition of the atrial ECM and how it changes with age is not yet known. This study utilized mass spectrometry to evaluate the composition of murine atria in young (12 weeks) and old (77 weeks) C57BL/6J mice. The tissue was decellularized, ECM and ECM-associated proteins were extracted with GuHCl, and proteins were deglycosylated to enable identification of glycosylated peptides. Two hundred and thirty-seven ECM and ECM-associated proteins were found to be significantly differentially expressed with age. Some proteins (MMP9, S100A9, VWA3A, CTSD, CCL8) were more than threefold increased with age, proteoglycans were modestly decreased, while the overall collagen content was markedly decreased. STRING network mapping of physical associations predicted that both PLOD3 and PDGFA interact with the collagens that decreased with age. The results suggest that the mechanism behind age-associated atrial stiffness is not due to an increase in collagen content as previously believed, but an increase in cross-linking, potentially facilitated by PLOD3. Additionally, several of the significant proteins have not previously been associated with cardiac aging and thus are potential drug targets for age-associated cardiac fibrosis and other age-associated conditions.
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Affiliation(s)
- Nathalie Ringström
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Charlotte Edling
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Giovanna Nalesso
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | | | - Kamalan Jeevaratnam
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
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4
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Jansen HJ, McRae MD, Belke DD, Rose RA. Chronic angiotensin-converting enzyme inhibition attenuates frailty and protects against atrial fibrillation in aging mice. Heart Rhythm 2025; 22:452-465. [PMID: 39019387 DOI: 10.1016/j.hrthm.2024.07.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 06/27/2024] [Accepted: 07/08/2024] [Indexed: 07/19/2024]
Abstract
BACKGROUND Aging is a major risk factor for atrial fibrillation (AF); however, not all individuals age at the same rate. Frailty, which is a measure of susceptibility to adverse health outcomes, can be quantified with a frailty index (FI). OBJECTIVE This study aimed to determine the effects of angiotensin-converting enzyme (ACE) inhibition on AF and atrial remodeling in aging and frail mice. METHODS Aging mice were treated with the ACE inhibitor enalapril for 6 months beginning at 16.5 months of age and frailty was quantified. AF susceptibility and atrial structure and function were assessed by intracardiac electrophysiology in anesthetized mice, high-resolution optical mapping in intact atrial preparations, patch clamping in isolated atrial myocytes, and histology and molecular biology in atrial tissues. RESULTS Enalapril attenuated frailty in aging mice with larger effects in females. AF susceptibility was increased in aging mice but attenuated by enalapril. AF susceptibility and duration also increased as a function of FI score. P-wave duration was increased and atrial conduction velocity was reduced in aging mice and improved after enalapril treatment. Furthermore, P-wave duration and atrial conduction velocity were strongly correlated with FI score. Atrial action potential upstroke velocity (Vmax) and Na+ current (INa) were reduced whereas atrial fibrosis was increased in aging mice. Action potential Vmax, INa, and fibrosis were improved by enalapril and also correlated with FI scores. CONCLUSION ACE inhibition with enalapril attenuates frailty and reduces AF susceptibility in aging mice by preventing atrial electrical and structural remodeling.
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Affiliation(s)
- Hailey J Jansen
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Megan D McRae
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Darrell D Belke
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Robert A Rose
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
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5
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Balaraman AK, Altamimi ASA, Babu MA, Goyal K, PadmaPriya G, Bansal P, Rajotiya S, Kumar MR, Rajput P, Imran M, Gupta G, Thangavelu L. The interplay of senescence and MMPs in myocardial infarction: implications for cardiac aging and therapeutics. Biogerontology 2025; 26:46. [PMID: 39832057 DOI: 10.1007/s10522-025-10190-6] [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: 11/18/2024] [Accepted: 01/04/2025] [Indexed: 01/22/2025]
Abstract
Aging is associated with a marked increase in cardiovascular diseases, such as myocardial infarction (MI). Cellular senescence is also a crucial factor in the development of age-related MI. Matrix metalloproteinases (MMPs) interaction with cellular senescence is a critical determinant of MI development and outcomes, most notably in the aged heart. After experiencing a heart attack, senescent cells exhibit a Senescence-Associated Secretory Phenotype (SASP) and are involved in tissue regeneration and chronic inflammation. MMPs are necessary for extracellular matrix proteolysis and have a biphasic effect, promoting early heart healing and detrimental change if overexpressed shortly. This review analyses the complex connection between senescence and MMPs in MI and how it influences elderly cardiac performance. Critical findings suggest that increasing cellular senescence in aged hearts elevates MMP activity and aggravates extended ventricular remodeling and dysfunction. Additionally, we explore potential therapeutics that address MMPs and senescence to enhance old MI patient myocardial performance and regeneration.
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Affiliation(s)
- Ashok Kumar Balaraman
- Research and Enterprise, University of Cyberjaya, Persiaran Bestari Cyber 11, Cyberjaya, Selangor, 63000, Malaysia
| | | | - M Arockia Babu
- Institute of Pharmaceutical Research, GLA University, Uttar Pradesh, Mathura, India
| | - Kavita Goyal
- Department of Biotechnology, Graphic Era (Deemed to Be University), Clement Town, Dehradun, 248002, India
| | - G PadmaPriya
- Department of Chemistry and Biochemistry, School of Sciences, JAIN (Deemed to Be University), Bangalore, Karnataka, India
| | - Pooja Bansal
- Department of Allied Healthcare and Sciences, Vivekananda Global University, Jaipur, Rajasthan, 303012, India
| | - Sumit Rajotiya
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, India
| | - M Ravi Kumar
- Department of Chemistry, Raghu Engineering College, Visakhapatnam, Andhra Pradesh, 531162, India
| | - Pranchal Rajput
- Division of Research and Innovation, Uttaranchal Institute of Pharmaceutical Sciences, Uttaranchal University, Dehradun, India
| | - Mohd Imran
- Department of Pharmaceutical Chemistry, College of Pharmacy, Northern Border University, 91911, Rafha, Saudi Arabia
- Center for Health Research, Northern Border University, Arar, Saudi Arabia
| | - Gaurav Gupta
- Centre for Research Impact & Outcome, Chitkara College of Pharmacy, Chitkara University, Punjab, India
- Centre of Medical and Bio-Allied Health Sciences Research, Ajman University, Ajman, United Arab Emirates
| | - Lakshmi Thangavelu
- Centre for Global Health Research, Saveetha Medical College, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India.
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6
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Rose RA, Howlett SE. Preclinical Studies on the Effects of Frailty in the Aging Heart. Can J Cardiol 2024; 40:1379-1393. [PMID: 38460611 DOI: 10.1016/j.cjca.2024.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/20/2024] [Accepted: 03/04/2024] [Indexed: 03/11/2024] Open
Abstract
Age is a major risk factor for the development of cardiovascular diseases in men and in women. However, not all people age at the same rate and those who are aging rapidly are considered frail, compared with their fit counterparts. Frailty is an important clinical challenge because those who are frail are more likely to develop and die from illnesses, including cardiovascular diseases, than fit people of the same age. This increase in susceptibility to cardiovascular diseases in older individuals might occur as the cellular and molecular mechanisms involved in the aging process facilitate structural and functional damage in the heart. Consistent with this, recent studies in murine frailty models have provided strong evidence that maladaptive cardiac remodelling in older mice is the most pronounced in mice with a high level of frailty. For example, there is evidence that ventricular hypertrophy and contractile dysfunction increase as frailty increases in aging mice. Additionally, fibrosis and slowing of conduction in the sinoatrial node and atria are proportional to the level of frailty. These modifications could predispose frail older adults to diseases like heart failure and atrial fibrillation. This preclinical work also raises the possibility that emerging interventions designed to "treat frailty" might also treat or prevent cardiovascular diseases. These findings might help to explain why frail older people are most likely to develop these disorders as they age.
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Affiliation(s)
- Robert A Rose
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada; Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
| | - Susan E Howlett
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Medicine (Geriatric Medicine), Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
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7
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Bisset ES, Howlett SE. Sex-specific effects of frailty on cardiac structure and function: insights from preclinical models. Can J Physiol Pharmacol 2024; 102:476-486. [PMID: 38489788 DOI: 10.1139/cjpp-2024-0009] [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] [Indexed: 03/17/2024]
Abstract
Advanced age is an independent risk factor for cardiovascular diseases in both sexes. This is thought to be due, in part, to age-dependent cellular, structural, and functional changes in the heart, a process known as cardiac aging. An emerging view is that cardiac aging leads to the accumulation of cellular and subcellular deficits that increase susceptibility to cardiovascular diseases. Still, people age at different rates, with those aging rapidly considered frail. Evidence suggests that frailty, rather than simply age, is a major risk factor for cardiovascular disease and predicts adverse outcomes in those affected. Recent studies in mouse models of frailty show that many adverse changes associated with cardiac aging are more prominent in mice with a high degree of frailty. This suggests that frailty sets the stage for late life cardiovascular diseases to flourish and raises the possibility that treating frailty may treat cardiovascular diseases. These studies show that ventricular dysfunction increases with frailty in males only, whereas atrial dysfunction increases with frailty in both sexes. These results may shed light on the reasons that men and women can be susceptible to different cardiovascular diseases as they age, and why frail individuals are especially vulnerable to these disorders.
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Affiliation(s)
- Elise S Bisset
- Department of Pharmacology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Susan E Howlett
- Department of Pharmacology, Dalhousie University, Halifax, NS B3H 4R2, Canada
- Department of Medicine (Geriatric Medicine), Dalhousie University, Halifax, NS B3H 4R2, Canada
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8
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Ninni S, Algalarrondo V, Brette F, Lemesle G, Fauconnier J. Left atrial cardiomyopathy: Pathophysiological insights, assessment methods and clinical implications. Arch Cardiovasc Dis 2024; 117:283-296. [PMID: 38490844 DOI: 10.1016/j.acvd.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 02/01/2024] [Accepted: 02/06/2024] [Indexed: 03/17/2024]
Abstract
Atrial cardiomyopathy is defined as any complex of structural, architectural, contractile or electrophysiological changes affecting atria, with the potential to produce clinically relevant manifestations. Most of our knowledge about the mechanistic aspects of atrial cardiomyopathy is derived from studies investigating animal models of atrial fibrillation and atrial tissue samples obtained from individuals who have a history of atrial fibrillation. Several noninvasive tools have been reported to characterize atrial cardiomyopathy in patients, which may be relevant for predicting the risk of incident atrial fibrillation and its related outcomes, such as stroke. Here, we provide an overview of the pathophysiological mechanisms involved in atrial cardiomyopathy, and discuss the complex interplay of these mechanisms, including aging, left atrial pressure overload, metabolic disorders and genetic factors. We discuss clinical tools currently available to characterize atrial cardiomyopathy, including electrocardiograms, cardiac imaging and serum biomarkers. Finally, we discuss the clinical impact of atrial cardiomyopathy, and its potential role for predicting atrial fibrillation, stroke, heart failure and dementia. Overall, this review aims to highlight the critical need for a clinically relevant definition of atrial cardiomyopathy to improve treatment strategies.
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Affiliation(s)
- Sandro Ninni
- CHU de Lille, Université de Lille, 59000 Lille, France.
| | - Vincent Algalarrondo
- Department of Cardiology, Bichat University Hospital, AP-HP, 75018 Paris, France
| | - Fabien Brette
- PhyMedExp, University of Montpellier, INSERM, CNRS, 34093 Montpellier, France
| | | | - Jérémy Fauconnier
- PhyMedExp, University of Montpellier, INSERM, CNRS, 34093 Montpellier, France
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9
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Gao P, Gao X, Xie B, Tse G, Liu T. Aging and atrial fibrillation: A vicious circle. Int J Cardiol 2024; 395:131445. [PMID: 37848123 DOI: 10.1016/j.ijcard.2023.131445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 09/17/2023] [Accepted: 10/12/2023] [Indexed: 10/19/2023]
Abstract
Atrial fibrillation (AF) is the commonest sustained cardiac arrhythmia observed in clinical practice. Its prevalence increases dramatically with advancing age. This review article discusses the recent advances in studies investigating the relationship between aging and AF and the possible underlying mechanisms.
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Affiliation(s)
- Pan Gao
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Xinyi Gao
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Bingxin Xie
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China
| | - Gary Tse
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China; School of Nursing and Health Studies, Hong Kong Metropolitan University, Hong Kong, China
| | - Tong Liu
- Tianjin Key Laboratory of Ionic-Molecular Function of Cardiovascular Disease, Department of Cardiology, Tianjin Institute of Cardiology, Second Hospital of Tianjin Medical University, Tianjin, China.
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10
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Zhang MJ, Gyberg DJ, Healy CL, Zhang N, Liu H, Dudley SC, O’Connell TD. Atrial Myopathy Quantified by Speckle-tracking Echocardiography in Mice. Circ Cardiovasc Imaging 2023; 16:e015735. [PMID: 37795649 PMCID: PMC10591948 DOI: 10.1161/circimaging.123.015735] [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: 05/25/2023] [Accepted: 08/17/2023] [Indexed: 10/06/2023]
Abstract
BACKGROUND Emerging evidence suggests that atrial myopathy may be the underlying pathophysiology that explains adverse cardiovascular outcomes in heart failure (HF) and atrial fibrillation. Lower left atrial (LA) function (strain) is a key biomarker of atrial myopathy, but murine LA strain has not been described, thus limiting translational investigation. Therefore, the objective of this study was to characterize LA function by speckle-tracking echocardiography in mouse models of atrial myopathy. METHODS We used 3 models of atrial myopathy in wild-type male and female C57Bl6/J mice: (1) aged 16 to 17 months, (2) Ang II (angiotensin II) infusion, and (3) high-fat diet+Nω-nitro-L-arginine methyl ester (HF with preserved ejection fraction, HFpEF). LA reservoir, conduit, and contractile strain were measured using speckle-tracking echocardiography from a modified parasternal long-axis window. Left ventricular systolic and diastolic function, and global longitudinal strain were also measured. Transesophageal rapid atrial pacing was used to induce atrial fibrillation. RESULTS LA reservoir, conduit, and contractile strain were significantly reduced in aged, Ang II and HFpEF mice compared with young controls. There were no sex-based interactions. Left ventricular diastolic function and global longitudinal strain were lower in aged, Ang II and HFpEF, but left ventricular ejection fraction was unchanged. Atrial fibrillation inducibility was low in young mice (5%), moderately higher in aged mice (20%), and high in Ang II (75%) and HFpEF (83%) mice. CONCLUSIONS Using speckle-tracking echocardiography, we observed reduced LA function in established mouse models of atrial myopathy with concurrent atrial fibrillation inducibility, thus providing the field with a timely and clinically relevant platform for understanding the pathophysiology and discovery of novel treatment targets for atrial myopathy.
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Affiliation(s)
- Michael J. Zhang
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN
- Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN
| | - Dylan J. Gyberg
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN
| | - Chastity L. Healy
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN
| | - Naixin Zhang
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN
| | - Hong Liu
- Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN
| | - Samuel C. Dudley
- Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN
- Lillehei Heart Institute, University of Minnesota, Minneapolis, MN
| | - Timothy D. O’Connell
- Department of Integrative Biology and Physiology, University of Minnesota, Minneapolis, MN
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11
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Huiskes FG, Creemers EE, Brundel BJJM. Dissecting the Molecular Mechanisms Driving Electropathology in Atrial Fibrillation: Deployment of RNA Sequencing and Transcriptomic Analyses. Cells 2023; 12:2242. [PMID: 37759465 PMCID: PMC10526291 DOI: 10.3390/cells12182242] [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: 07/15/2023] [Revised: 08/30/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
Despite many efforts to treat atrial fibrillation (AF), the most common progressive and age-related cardiac tachyarrhythmia in the Western world, the efficacy is still suboptimal. A plausible reason for this is that current treatments are not directed at underlying molecular root causes that drive electrical conduction disorders and AF (i.e., electropathology). Insights into AF-induced transcriptomic alterations may aid in a deeper understanding of electropathology. Specifically, RNA sequencing (RNA-seq) facilitates transcriptomic analyses and discovery of differences in gene expression profiles between patient groups. In the last decade, various RNA-seq studies have been conducted in atrial tissue samples of patients with AF versus controls in sinus rhythm. Identified differentially expressed molecular pathways so far include pathways related to mechanotransduction, ECM remodeling, ion channel signaling, and structural tissue organization through developmental and inflammatory signaling pathways. In this review, we provide an overview of the available human AF RNA-seq studies and highlight the molecular pathways identified. Additionally, a comparison is made between human RNA-seq findings with findings from experimental AF model systems and we discuss contrasting findings. Finally, we elaborate on new exciting RNA-seq approaches, including single-nucleotide variants, spatial transcriptomics and profiling of different populations of total RNA, small RNA and long non-coding RNA.
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Affiliation(s)
- Fabries G. Huiskes
- Department of Physiology, Amsterdam UMC, Location Vrije Universiteit, VUmc, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, 1081 HZ, Amsterdam, The Netherlands;
- Department of Experimental Cardiology, Amsterdam UMC, Location AMC, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, 1105 AZ Amsterdam, The Netherlands;
| | - Esther E. Creemers
- Department of Experimental Cardiology, Amsterdam UMC, Location AMC, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, 1105 AZ Amsterdam, The Netherlands;
| | - Bianca J. J. M. Brundel
- Department of Physiology, Amsterdam UMC, Location Vrije Universiteit, VUmc, Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, 1081 HZ, Amsterdam, The Netherlands;
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12
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Marcozzi S, Bigossi G, Giuliani ME, Giacconi R, Cardelli M, Piacenza F, Orlando F, Segala A, Valerio A, Nisoli E, Brunetti D, Puca A, Boschi F, Gaetano C, Mongelli A, Lattanzio F, Provinciali M, Malavolta M. Comprehensive longitudinal non-invasive quantification of healthspan and frailty in a large cohort (n = 546) of geriatric C57BL/6 J mice. GeroScience 2023; 45:2195-2211. [PMID: 36702990 PMCID: PMC10651584 DOI: 10.1007/s11357-023-00737-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 01/17/2023] [Indexed: 01/28/2023] Open
Abstract
Frailty is an age-related condition characterized by a multisystem functional decline, increased vulnerability to stressors, and adverse health outcomes. Quantifying the degree of frailty in humans and animals is a health measure useful for translational geroscience research. Two frailty measurements, namely the frailty phenotype (FP) and the clinical frailty index (CFI), have been validated in mice and are frequently applied in preclinical research. However, these two tools are based on different concepts and do not necessarily identify the same mice as frail. In particular, the FP is based on a dichotomous classification that suffers from high sample size requirements and misclassification problems. Based on the monthly longitudinal non-invasive assessment of frailty in a large cohort of mice, here we develop an alternative scoring method, which we called physical function score (PFS), proposed as a continuous variable that resumes into a unique function, the five criteria included in the FP. This score would not only reduce misclassification of frailty but it also makes the two tools, PFS and CFI, integrable to provide an overall measurement of health, named vitality score (VS) in aging mice. VS displays a higher association with mortality than PFS or CFI and correlates with biomarkers related to the accumulation of senescent cells and the epigenetic clock. This longitudinal non-invasive assessment strategy and the VS may help to overcome the different sensitivity in frailty identification, reduce the sample size in longitudinal experiments, and establish the effectiveness of therapeutic/preventive interventions for frailty or other age-related diseases in geriatric animals.
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Affiliation(s)
- Serena Marcozzi
- Advanced Technology Center for Aging Research, IRCCS INRCA, 60121, Ancona, Italy
- Scientific Direction, IRCCS INRCA, 60124, Ancona, Italy
| | - Giorgia Bigossi
- Advanced Technology Center for Aging Research, IRCCS INRCA, 60121, Ancona, Italy
| | - Maria Elisa Giuliani
- Advanced Technology Center for Aging Research, IRCCS INRCA, 60121, Ancona, Italy
| | - Robertina Giacconi
- Advanced Technology Center for Aging Research, IRCCS INRCA, 60121, Ancona, Italy
| | - Maurizio Cardelli
- Advanced Technology Center for Aging Research, IRCCS INRCA, 60121, Ancona, Italy
| | - Francesco Piacenza
- Advanced Technology Center for Aging Research, IRCCS INRCA, 60121, Ancona, Italy
| | - Fiorenza Orlando
- Experimental Animal Models for Aging Unit, Scientific Technological Area, IRCCS INRCA, 60015, Falconara Marittima (AN), Italy
| | - Agnese Segala
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa, 11, 25123, Brescia, Italy
| | - Alessandra Valerio
- Department of Molecular and Translational Medicine, University of Brescia, Viale Europa, 11, 25123, Brescia, Italy
| | - Enzo Nisoli
- Center for Study and Research On Obesity, Department of Medical Biotechnology and Translational Medicine, University of Milan, Via Vanvitelli, 32, 20129, Milan, Italy
| | - Dario Brunetti
- Medical Genetics and Neurogenetics Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20126, Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, University of Milan, 20129, Milan, Italy
| | - Annibale Puca
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Via Salvatore Allende, 84081, Baronissi, Salerno, Italy
- Cardiovascular Research Unit, IRCCS MultiMedica, 20138, Milan, Italy
| | - Federico Boschi
- Department of Computer Science, University of Verona, Strada Le Grazie 15, 37134, Verona, Italy
| | - Carlo Gaetano
- Laboratory of Epigenetics, Istituti Clinici Scientifici Maugeri IRCCS, Via Maugeri 10, 27100, Pavia, Italy
| | - Alessia Mongelli
- Laboratory of Epigenetics, Istituti Clinici Scientifici Maugeri IRCCS, Via Maugeri 10, 27100, Pavia, Italy
| | | | - Mauro Provinciali
- Advanced Technology Center for Aging Research, IRCCS INRCA, 60121, Ancona, Italy
| | - Marco Malavolta
- Advanced Technology Center for Aging Research, IRCCS INRCA, 60121, Ancona, Italy.
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13
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Ringström N, Edling C, Nalesso G, Jeevaratnam K. Framing Heartaches: The Cardiac ECM and the Effects of Age. Int J Mol Sci 2023; 24:4713. [PMID: 36902143 PMCID: PMC10003270 DOI: 10.3390/ijms24054713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/10/2023] [Accepted: 02/15/2023] [Indexed: 03/05/2023] Open
Abstract
The cardiac extracellular matrix (ECM) is involved in several pathological conditions, and age itself is also associated with certain changes in the heart: it gets larger and stiffer, and it develops an increased risk of abnormal intrinsic rhythm. This, therefore, makes conditions such as atrial arrythmia more common. Many of these changes are directly related to the ECM, yet the proteomic composition of the ECM and how it changes with age is not fully resolved. The limited research progress in this field is mainly due to the intrinsic challenges in unravelling tightly bound cardiac proteomic components and also the time-consuming and costly dependency on animal models. This review aims to give an overview of the composition of the cardiac ECM, how different components aid the function of the healthy heart, how the ECM is remodelled and how it is affected by ageing.
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Affiliation(s)
| | | | | | - Kamalan Jeevaratnam
- Faculty of Health and Medical Science, University of Surrey, Guildford GU2 7AL, UK
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14
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Resting membrane potential is less negative in trabeculae from right atrial appendages of women, but action potential duration does not shorten with age. J Mol Cell Cardiol 2023; 176:1-10. [PMID: 36681268 DOI: 10.1016/j.yjmcc.2023.01.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 01/11/2023] [Accepted: 01/14/2023] [Indexed: 01/19/2023]
Abstract
AIMS The incidence of atrial fibrillation (AF) increases with age. Women have a lower risk. Little is known on the impact of age, sex and clinical variables on action potentials (AP) recorded in right atrial tissue obtained during open heart surgery from patients in sinus rhythm (SR) and in longstanding AF. We here investigated whether age or sex have an impact on the shape of AP recorded in vitro from right atrial tissue. METHODS We performed multivariable analysis of individual AP data from trabeculae obtained during heart surgery of patients in SR (n = 320) or in longstanding AF (n = 201). AP were recorded by sharp microelectrodes at 37 °C at 1 Hz. Impact of clinical variables were modeled using a multivariable mixed model regression. RESULTS In SR, AP duration at 90% repolarization (APD90) increased with age. Lower ejection fraction and higher body mass index were associated with smaller action potential amplitude (APA) and maximum upstroke velocity (Vmax). The use of beta-blockers was associated with larger APD90. In tissues from women, resting membrane potential was less negative and APA as well as Vmax were smaller. Besides shorter APD20 in elderly patients, effects of age and sex on atrial AP were lost in AF. CONCLUSION The higher probability to develop AF at advanced age cannot be explained by a shortening in APD90. Less negative RMP and lower upstroke velocity might contribute to lower incidence of AF in women, which may be of clinical relevance.
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15
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Biochemical Predictors of New-Onset Atrial Fibrillation after Ascending Aorta Replacement Surgery in Acute Type A Aortic Dissection Patients. J Card Surg 2023. [DOI: 10.1155/2023/2612292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Objective. This study aimed to determine the risk factors of new-onset postoperative atrial fibrillation after ascending aortic replacement in acute type A aortic dissection patients, with emphasis on biochemical parameters. Methods. From Jan 2020 to Dec 2021, a total of 435 acute type A aortic dissection patients who underwent ascending aortic replacement and without a history of atrial fibrillation were retrospectively analyzed in this study. Perioperative data of these patients were obtained from the hospital’s database. The 30-day follow-up was via telephone interviews. The multivariate regression analysis was used to identify risk factors that may be predictive of postoperative atrial fibrillation. Results. 218 (50.1%) patients experienced postoperative atrial fibrillation after ascending aorta replacement surgery. Older age (OR = 1.081 (1.059–1.104),
), higher total bile acid (OR = 1.064 (1.024–1.106),
= 0.002), glucose (OR = 1.180 (1.038–1.342),
= 0.012), and serum potassium (OR = 2.313 (1.078–4.960),
= 0.031) were identified by multivariate regression analysis as risk factors of postoperative atrial fibrillation. The multivariate regression analysis prediction model incorporating these four factors had a good prediction effect (AUC = 0.769 (0.723–0.816),
). Conclusions. Older age, higher total bile acid, glucose, and serum potassium were risk factors of postoperative atrial fibrillation after ascending aortic replacement surgery in acute type A aortic dissection patients.
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16
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Murphy MB, Kannankeril PJ, Murray KT. Overview of programmed electrical stimulation to assess atrial fibrillation susceptibility in mice. Front Physiol 2023; 14:1149023. [PMID: 37113690 PMCID: PMC10126433 DOI: 10.3389/fphys.2023.1149023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/31/2023] [Indexed: 04/29/2023] Open
Abstract
Atrial fibrillation (AF) is the most common human arrhythmia and is associated with increased risk of stroke, dementia, heart failure, and death. Among several animal models that have been used to investigate the molecular determinants of AF, mouse models have become the most prevalent due to low cost, ease of genetic manipulation, and similarity to human disease. Programmed electrical stimulation (PES) using intracardiac or transesophageal atrial pacing is used to induce AF as most mouse models do not develop spontaneous AF. However, there is a lack of standardized methodology resulting in numerous PES protocols in the literature that differ with respect to multiple parameters, including pacing protocol and duration, stimulus amplitude, pulse width, and even the definition of AF. Given this complexity, the selection of the appropriate atrial pacing protocol for a specific model has been arbitrary. Herein we review the development of intracardiac and transesophageal PES, including commonly used protocols, selected experimental models, and advantages and disadvantages of both techniques. We also emphasize detection of artifactual AF induction due to unintended parasympathetic stimulation, which should be excluded from results. We recommend that the optimal pacing protocol to elicit an AF phenotype should be individualized to the specific model of genetic or acquired risk factors, with an analysis using several definitions of AF as an endpoint.
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17
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Hashimoto K, Harada N, Kimata M, Kawamura Y, Fujita N, Sekizawa A, Ono Y, Obuchi Y, Takayama T, Kasamaki Y, Tanaka Y. Age-related reference intervals for ambulatory electrocardiographic parameters in healthy individuals. Front Cardiovasc Med 2023; 10:1099157. [PMID: 36950291 PMCID: PMC10026132 DOI: 10.3389/fcvm.2023.1099157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 02/16/2023] [Indexed: 03/08/2023] Open
Abstract
Background The advent of novel monitoring technologies has dramatically increased the use of ambulatory electrocardiography (AECG) devices. However, few studies have conducted detailed large-scale investigations on the incidence of arrhythmias over 24 h, especially ectopy, in healthy individuals over a wide age range. Objectives This study aimed to investigate the incidence of arrhythmias detected using AECG and associated factors, in healthy individuals, over a wide age range. Methods In this cross-sectional study, we performed AECG on 365 healthy volunteers (median [interquartile range]: 48 [36, 67], 20-89 years, 165 men) under free-running conditions for 24 h. Ultrasonic echocardiography and heart rate variability analysis were performed to explore the factors associated with the incidence of arrhythmias. Results The 97.5th percentile of single ventricular ectopy (VE) was 149/day, 254/day, and 1,682/day in the 20-39-, 40-59- and 60-89-year age groups, respectively; that of single supraventricular ectopy (SVE) was 131/day, 232/day, and 1,063/day, respectively. Multivariate analysis revealed that aging was the only independent significant factor influencing the frequency of VE (β = 0.207, P = 0.001). Age (β = 0.642, P < 0.001), body mass index (BMI) (β = -0.112, P = 0.009), and the root mean square of successive differences in RR intervals (β = 0.097, P = 0.035) were factors significantly associated with SVE frequency. Conclusions Age-specific reference intervals of VE and SVE in a large population of healthy participants over a wide age range were generated. VE and SVE increased with age; SVE was influenced by BMI and the aging-induced decrease in parasympathetic tone activity.
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Affiliation(s)
- Kenichi Hashimoto
- Department of General Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
- Correspondence: Kenichi Hashimoto
| | - Naomi Harada
- Department of General Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Motohiro Kimata
- Department of General Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Yusuke Kawamura
- Department of General Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
- Department of Integrative Physiology and Bio-Nano Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Naoya Fujita
- Department of General Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Akinori Sekizawa
- Department of General Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Yosuke Ono
- Department of General Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Yasuhiro Obuchi
- Department of General Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
| | - Tadateru Takayama
- Department of General Medicine, Nihon University School of Medicine, Tokyo, Japan
| | - Yuji Kasamaki
- Department of General Medicine, Kanazawa Medical College Himi Municipal Hospital, Himi, Toyama, Japan
| | - Yuji Tanaka
- Department of General Medicine, National Defense Medical College, Tokorozawa, Saitama, Japan
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18
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Gao X, Lai Y, Luo X, Peng D, Li Q, Zhou H, Xue Y, Guo H, Zhao J, Yang H, Kuang S, Wang Z, Zhang M, Deng C, Wu S, Rao F. Acetyltransferase p300 regulates atrial fibroblast senescence and age-related atrial fibrosis through p53/Smad3 axis. Aging Cell 2022; 22:e13743. [PMID: 36468256 PMCID: PMC9835568 DOI: 10.1111/acel.13743] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 09/30/2022] [Accepted: 11/06/2022] [Indexed: 12/09/2022] Open
Abstract
Atrial fibrosis induced by aging is one of the main causes of atrial fibrillation (AF), but the potential molecular mechanism is not clear. Acetyltransferase p300 participates in the cellular senescence and fibrosis, which might be involved in the age-related atrial fibrosis. Four microarray datasets generated from atrial tissue of AF patients and sinus rhythm (SR) controls were analyzed to find the possible relationship of p300 (EP300) with senescence and fibrosis. And then, biochemical assays and in vivo electrophysiological examination were performed on older AF patients, aging mice, and senescent atrial fibroblasts. The results showed that (1) the left atrial tissues of older AF patients, aging mouse, and senescence human atrial fibroblasts had more severe atrial fibrosis and higher protein expression levels of p300, p53/acetylated p53 (ac-p53)/p21, Smad3/p-Smads, and fibrosis-related factors. (2) p300 inhibitor curcumin and p300 knockdown treated aging mouse and senescence human atrial fibroblasts reduced the senescence ratio of atrial fibroblasts, ameliorated the atrial fibrosis, and decreased the AF inducibility. In contrast, over-expression of p300 can lead to the senescence of atrial fibroblasts and atrial fibrosis. (3) p53 knockdown decreased the expression of aging and fibrosis-related proteins. (4) Co-immunoprecipitation and immunofluorescence showed that p53 forms a complex with smad3 and directly regulates the expression of smad3 in atrial fibroblasts. Our findings suggest that the mechanism of atrial fibrosis induced by aging is, at least, partially dependent on the regulation of p300, which provides new sights into the AF treatment, especially for the elderly.
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Affiliation(s)
- Xiao‐Yan Gao
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - Ying‐Yu Lai
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Department of PharmacyThe People's Hospital of HezhouHezhouChina
| | - Xue‐Shan Luo
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - De‐Wei Peng
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - Qiao‐Qiao Li
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - Hui‐Shan Zhou
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - Yu‐Mei Xue
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - Hui‐Ming Guo
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - Jun‐Fei Zhao
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - Hui Yang
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - Su‐Juan Kuang
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - Zhao‐Yu Wang
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - Meng‐Zhen Zhang
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - Chun‐Yu Deng
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - Shu‐Lin Wu
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
| | - Fang Rao
- Guangdong Cardiovascular Institute, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina,Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhouChina
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19
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Bapat A, Li G, Xiao L, Yeri A, Hulsmans M, Grune J, Yamazoe M, Schloss MJ, Iwamoto Y, Tedeschi J, Yang X, Nahrendorf M, Rosenzweig A, Ellinor PT, Das S, Milan D. Genetic inhibition of serum glucocorticoid kinase 1 prevents obesity-related atrial fibrillation. JCI Insight 2022; 7:160885. [PMID: 35998035 PMCID: PMC9675459 DOI: 10.1172/jci.insight.160885] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 08/19/2022] [Indexed: 01/19/2023] Open
Abstract
Obesity is an important risk factor for atrial fibrillation (AF), but a better mechanistic understanding of obesity-related atrial fibrillation is required. Serum glucocorticoid kinase 1 (SGK1) is a kinase positioned within multiple obesity-related pathways, and prior work has shown a pathologic role of SGK1 signaling in ventricular arrhythmias. We validated a mouse model of obesity-related AF using wild-type mice fed a high-fat diet. RNA sequencing of atrial tissue demonstrated substantial differences in gene expression, with enrichment of multiple SGK1-related pathways, and we showed upregulated of SGK1 transcription, activation, and signaling in obese atria. Mice expressing a cardiac specific dominant-negative SGK1 were protected from obesity-related AF, through effects on atrial electrophysiology, action potential characteristics, structural remodeling, inflammation, and sodium current. Overall, this study demonstrates the promise of targeting SGK1 in a mouse model of obesity-related AF.
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Affiliation(s)
- Aneesh Bapat
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Demoulas Family Foundation Center for Cardiac Arrhythmias, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Guoping Li
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Ling Xiao
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Ashish Yeri
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Maarten Hulsmans
- Center for Systems Biology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, Massachusetts, USA
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Jana Grune
- Center for Systems Biology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, Massachusetts, USA
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
- German Centre for Cardiovascular Research, Berlin, Germany
| | - Masahiro Yamazoe
- Center for Systems Biology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, Massachusetts, USA
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Maximilian J. Schloss
- Center for Systems Biology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, Massachusetts, USA
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Yoshiko Iwamoto
- Center for Systems Biology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, Massachusetts, USA
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Justin Tedeschi
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Xinyu Yang
- Fangshan Hospital of Beijing, University of Traditional Chinese Medicine, Beijing, China
| | - Matthias Nahrendorf
- Center for Systems Biology, Massachusetts General Hospital Research Institute and Harvard Medical School, Boston, Massachusetts, USA
- Department of Radiology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Internal Medicine I, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Anthony Rosenzweig
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Patrick T. Ellinor
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Demoulas Family Foundation Center for Cardiac Arrhythmias, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Saumya Das
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Demoulas Family Foundation Center for Cardiac Arrhythmias, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - David Milan
- Cardiovascular Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Leducq Foundation, Boston, Massachusetts, USA
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20
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Li G, Yang J, Zhang D, Wang X, Han J, Guo X. Research Progress of Myocardial Fibrosis and Atrial Fibrillation. Front Cardiovasc Med 2022; 9:889706. [PMID: 35958428 PMCID: PMC9357935 DOI: 10.3389/fcvm.2022.889706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 06/10/2022] [Indexed: 12/04/2022] Open
Abstract
With the aging population and the increasing incidence of basic illnesses such as hypertension and diabetes (DM), the incidence of atrial fibrillation (AF) has increased significantly. AF is the most common arrhythmia in clinical practice, which can cause heart failure (HF) and ischemic stroke (IS), increasing disability and mortality. Current studies point out that myocardial fibrosis (MF) is one of the most critical substrates for the occurrence and maintenance of AF. Although myocardial biopsy is the gold standard for evaluating MF, it is rarely used in clinical practice because it is an invasive procedure. In addition, serological indicators and imaging methods have also been used to evaluate MF. Nevertheless, the accuracy of serological markers in evaluating MF is controversial. This review focuses on the pathogenesis of MF, serological evaluation, imaging evaluation, and anti-fibrosis treatment to discuss the existing problems and provide new ideas for MF and AF evaluation and treatment.
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Affiliation(s)
- Guangling Li
- Department of Cardiology, Lanzhou University Second Hospital, Lanzhou University, Lanzhou, China
| | - Jing Yang
- Department of Pathology, Gansu Provincial Hospital, Lanzhou, China
| | - Demei Zhang
- Department of Cardiology, Lanzhou University Second Hospital, Lanzhou University, Lanzhou, China
| | - Xiaomei Wang
- Department of Cardiology, Lanzhou University Second Hospital, Lanzhou University, Lanzhou, China
| | - Jingjing Han
- Department of Cardiology, Lanzhou University Second Hospital, Lanzhou University, Lanzhou, China
| | - Xueya Guo
- Department of Cardiology, Lanzhou University Second Hospital, Lanzhou University, Lanzhou, China
- *Correspondence: Xueya Guo,
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21
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Abstract
Frailty is a complex syndrome affecting a growing sector of the global population as medical developments have advanced human mortality rates across the world. Our current understanding of frailty is derived from studies conducted in the laboratory as well as the clinic, which have generated largely phenotypic information. Far fewer studies have uncovered biological underpinnings driving the onset and progression of frailty, but the stage is set to advance the field with preclinical and clinical assessment tools, multiomics approaches together with physiological and biochemical methodologies. In this article, we provide comprehensive coverage of topics regarding frailty assessment, preclinical models, interventions, and challenges as well as clinical frameworks and prevalence. We also identify central biological mechanisms that may be at play including mitochondrial dysfunction, epigenetic alterations, and oxidative stress that in turn, affect metabolism, stress responses, and endocrine and neuromuscular systems. We review the role of metabolic syndrome, insulin resistance and visceral obesity, focusing on glucose homeostasis, adenosine monophosphate-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), and nicotinamide adenine dinucleotide (NAD+ ) as critical players influencing the age-related loss of health. We further focus on how immunometabolic dysfunction associates with oxidative stress in promoting sarcopenia, a key contributor to slowness, weakness, and fatigue. We explore the biological mechanisms involved in stem cell exhaustion that affect regeneration and may contribute to the frailty-associated decline in resilience and adaptation to stress. Together, an overview of the interplay of aging biology with genetic, lifestyle, and environmental factors that contribute to frailty, as well as potential therapeutic targets to lower risk and slow the progression of ongoing disease is covered. © 2022 American Physiological Society. Compr Physiol 12:1-46, 2022.
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Affiliation(s)
- Laís R. Perazza
- Department of Physical Therapy and Athletic Training, Boston University, Boston, Massachusetts, USA
| | - Holly M. Brown-Borg
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota, USA
| | - LaDora V. Thompson
- Department of Physical Therapy and Athletic Training, Boston University, Boston, Massachusetts, USA
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22
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Electro-anatomical computational cardiology in humans and experimental animal models. TRANSLATIONAL RESEARCH IN ANATOMY 2022. [DOI: 10.1016/j.tria.2022.100162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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23
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Sánchez FJ, Pueyo E, Diez ER. Strain Echocardiography to Predict Postoperative Atrial Fibrillation. Int J Mol Sci 2022; 23:1355. [PMID: 35163278 PMCID: PMC8836170 DOI: 10.3390/ijms23031355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/23/2022] [Accepted: 01/23/2022] [Indexed: 11/16/2022] Open
Abstract
Postoperative atrial fibrillation (POAF) complicates 15% to 40% of cardiovascular surgeries. Its incidence progressively increases with aging, reaching 50% in octogenarians. This arrhythmia is usually transient but it increases the risk of embolic stroke, prolonged hospital stay, and cardiovascular mortality. Though many pathophysiological mechanisms are known, POAF prediction is still a hot topic of discussion. Doppler echocardiogram and, lately, strain echocardiography have shown significant capacity to predict POAF. Alterations in oxidative stress, calcium handling, mitochondrial dysfunction, inflammation, fibrosis, and tissue aging are among the mechanisms that predispose patients to the perfect "atrial storm". Manifestations of these mechanisms have been related to enlarged atria and impaired function, which can be detected prior to surgery. Specific alterations in the atrial reservoir and pump function, as well as atrial dyssynchrony determined by echocardiographic atrial strain, can predict POAF and help to shed light on which patients could benefit from preventive therapy.
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Affiliation(s)
| | - Esther Pueyo
- BSICOS Group, I3A, IIS Aragón, University of Zaragoza, 50018 Zaragoza, Spain;
- CIBER-BBN, 28029 Madrid, Spain
| | - Emiliano Raúl Diez
- Faculty of Medical Sciences, National University of Cuyo, Mendoza 5500, Argentina;
- Institute of Medical and Experimental Biology of Cuyo, IMBECU-UNCuyo-CONICET, Mendoza 5500, Argentina
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24
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Jansen HJ, Moghtadaei M, Rafferty SA, Rose RA. Loss of natriuretic peptide receptor C enhances sinoatrial node dysfunction in aging and frail mice. J Gerontol A Biol Sci Med Sci 2021; 77:902-908. [PMID: 34865023 DOI: 10.1093/gerona/glab357] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Indexed: 11/14/2022] Open
Abstract
Heart rate is controlled by the sinoatrial node (SAN). SAN dysfunction is highly prevalent in aging; however, not all individuals age at the same rate. Rather, health status during aging is affected by frailty. Natriuretic peptides regulate SAN function in part by activating natriuretic peptide receptor C (NPR-C). The impacts of NPR-C on HR and SAN function in aging and as a function of frailty are unknown. Frailty was measured in aging wildtype (WT) and NPR-C knockout (NPR-C -/-) mice using a mouse clinical frailty index (FI). HR and SAN structure and function were investigated using intracardiac electrophysiology in anesthetized mice, high-resolution optical mapping in intact atrial preparations, histology and molecular biology. NPR-C -/- mice rapidly became frail leading to shortened lifespan. HR and SAN recovery time were increased in older vs. younger mice and this was exacerbated in NPR-C -/- mice; however, there was substantial variability among age groups and genotypes. HR and SAN recovery time were correlated with FI score and fell along a continuum regardless of age or genotype. Optical mapping demonstrates impairments in SAN function that were also strongly correlated with FI score. SAN fibrosis was increased in aged and NPR-C -/- mice and was graded by FI score. Loss of NPR-C results in accelerated aging due to a rapid decline in health status in association with impairments in HR and SAN function. Frailty assessment was effective and often better able to distinguish aging-dependent changes in SAN function in the setting of shorted lifespan due to loss of NPR-C.
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Affiliation(s)
- Hailey J Jansen
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine , University of Calgary, Calgary, Alberta, Canada
| | - Motahareh Moghtadaei
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine , University of Calgary, Calgary, Alberta, Canada
| | - Sara A Rafferty
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Robert A Rose
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine , University of Calgary, Calgary, Alberta, Canada
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Dela Justina V, Miguez JSG, Priviero F, Sullivan JC, Giachini FR, Webb RC. Sex Differences in Molecular Mechanisms of Cardiovascular Aging. FRONTIERS IN AGING 2021; 2:725884. [PMID: 35822017 PMCID: PMC9261391 DOI: 10.3389/fragi.2021.725884] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/25/2021] [Indexed: 12/12/2022]
Abstract
Cardiovascular disease (CVD) is still the leading cause of illness and death in the Western world. Cardiovascular aging is a progressive modification occurring in cardiac and vascular morphology and physiology where increased endothelial dysfunction and arterial stiffness are observed, generally accompanied by increased systolic blood pressure and augmented pulse pressure. The effects of biological sex on cardiovascular pathophysiology have long been known. The incidence of hypertension is higher in men, and it increases in postmenopausal women. Premenopausal women are protected from CVD compared with age-matched men and this protective effect is lost with menopause, suggesting that sex-hormones influence blood pressure regulation. In parallel, the heart progressively remodels over the course of life and the pattern of cardiac remodeling also differs between the sexes. Lower autonomic tone, reduced baroreceptor response, and greater vascular function are observed in premenopausal women than men of similar age. However, postmenopausal women have stiffer arteries than their male counterparts. The biological mechanisms responsible for sex-related differences observed in cardiovascular aging are being unraveled over the last several decades. This review focuses on molecular mechanisms underlying the sex-differences of CVD in aging.
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Affiliation(s)
- Vanessa Dela Justina
- Graduate Program in Biological Sciences, Federal University of Goiás, Goiânia, Brazil
| | | | - Fernanda Priviero
- Cardiovascular Translational Research Center, University of South Carolina, Columbia, SC, United States
| | - Jennifer C. Sullivan
- Department of Physiology, Medical College of Georgia at Augusta University, Augusta, GA, United States
| | - Fernanda R. Giachini
- Graduate Program in Biological Sciences, Federal University of Goiás, Goiânia, Brazil
- Institute of Biological Sciences and Health, Federal University of Mato Grosso, Barra do Garças, Brazil
| | - R. Clinton Webb
- Cardiovascular Translational Research Center, University of South Carolina, Columbia, SC, United States
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26
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Jansen HJ, Moghtadaei M, Rafferty SA, Rose RA. Atrial Fibrillation in Aging and Frail Mice: Modulation by Natriuretic Peptide Receptor C. Circ Arrhythm Electrophysiol 2021; 14:e010077. [PMID: 34490788 DOI: 10.1161/circep.121.010077] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Hailey J Jansen
- Department of Cardiac Sciences, Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada (H.J.J., M.M., R.A.R.)
| | - Motahareh Moghtadaei
- Department of Cardiac Sciences, Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada (H.J.J., M.M., R.A.R.)
| | - Sara A Rafferty
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada (S.A.R.)
| | - Robert A Rose
- Department of Cardiac Sciences, Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada (H.J.J., M.M., R.A.R.)
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27
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Verschoor CP, Lin DTS, Kobor MS, Mian O, Ma J, Pare G, Ybazeta G. Epigenetic age is associated with baseline and 3-year change in frailty in the Canadian Longitudinal Study on Aging. Clin Epigenetics 2021; 13:163. [PMID: 34425884 PMCID: PMC8381580 DOI: 10.1186/s13148-021-01150-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 08/11/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The trajectory of frailty in older adults is important to public health; therefore, markers that may help predict this and other important outcomes could be beneficial. Epigenetic clocks have been developed and are associated with various health-related outcomes and sociodemographic factors, but associations with frailty are poorly described. Further, it is uncertain whether newer generations of epigenetic clocks, trained on variables other than chronological age, would be more strongly associated with frailty than earlier developed clocks. Using data from the Canadian Longitudinal Study on Aging (CLSA), we tested the hypothesis that clocks trained on phenotypic markers of health or mortality (i.e., Dunedin PoAm, GrimAge, PhenoAge and Zhang in Nat Commun 8:14617, 2017) would best predict changes in a 76-item frailty index (FI) over a 3-year interval, as compared to clocks trained on chronological age (i.e., Hannum in Mol Cell 49:359-367, 2013, Horvath in Genome Biol 14:R115, 2013, Lin in Aging 8:394-401, 2016, and Yang Genome Biol 17:205, 2016). RESULTS We show that in 1446 participants, phenotype/mortality-trained clocks outperformed age-trained clocks with regard to the association with baseline frailty (mean = 0.141, SD = 0.075), the greatest of which is GrimAge, where a 1-SD increase in ΔGrimAge (i.e., the difference from chronological age) was associated with a 0.020 increase in frailty (95% CI 0.016, 0.024), or ~ 27% relative to the SD in frailty. Only GrimAge and Hannum (Mol Cell 49:359-367, 2013) were significantly associated with change in frailty over time, where a 1-SD increase in ΔGrimAge and ΔHannum 2013 was associated with a 0.0030 (95% CI 0.0007, 0.0050) and 0.0028 (95% CI 0.0007, 0.0050) increase over 3 years, respectively, or ~ 7% relative to the SD in frailty change. CONCLUSION Both prevalence and change in frailty are associated with increased epigenetic age. However, not all clocks are equally sensitive to these outcomes and depend on their underlying relationship with chronological age, healthspan and lifespan. Certain clocks were significantly associated with relatively short-term changes in frailty, thereby supporting their utility in initiatives and interventions to promote healthy aging.
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Affiliation(s)
- Chris P Verschoor
- Health Sciences North Research Institute, 41 Ramsey Lake Road, Sudbury, ON, P3E 5J1, Canada.
- Northern Ontario School of Medicine, Sudbury, ON, Canada.
- Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, ON, Canada.
| | - David T S Lin
- BC Children's Hospital Research Institute, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Michael S Kobor
- BC Children's Hospital Research Institute, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Oxana Mian
- Health Sciences North Research Institute, 41 Ramsey Lake Road, Sudbury, ON, P3E 5J1, Canada
| | - Jinhui Ma
- Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, ON, Canada
| | - Guillaume Pare
- Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, ON, Canada
| | - Gustavo Ybazeta
- Health Sciences North Research Institute, 41 Ramsey Lake Road, Sudbury, ON, P3E 5J1, Canada
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Dorey TW, Jansen HJ, Moghtadaei M, Jamieson KL, Rose RA. Impacts of frailty on heart rate variability in aging mice: Roles of the autonomic nervous system and sinoatrial node. Heart Rhythm 2021; 18:1999-2008. [PMID: 34371195 DOI: 10.1016/j.hrthm.2021.07.069] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/27/2021] [Accepted: 07/29/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Heart rate variability (HRV) is determined by intrinsic sinoatrial node (SAN) activity and the autonomic nervous system (ANS). HRV is reduced in aging; however, aging is heterogeneous. Frailty, which can be measured using a frailty index (FI), can quantify health status in aging separately from chronological age. OBJECTIVE The purpose of this study was to investigate the impacts of age and frailty on HRV in mice. METHODS Frailty was measured in aging mice between 10 and 130 weeks of age. HRV was assessed using time domain, frequency domain, and Poincaré plot analyses in anesthetized mice at baseline and after ANS blockade, as well as in isolated atrial preparations. RESULTS HRV was reduced in aged mice (90-130 weeks and 50-80 weeks old) compared to younger mice (10-30 weeks old); however, there was substantial variability within age groups. In contrast, HRV was strongly correlated with FI score regardless of chronological age. ANS blockade resulted in reductions in heart rate that were largest in 90- to 130-week-old mice and were correlated with FI score. HRV after ANS blockade or in isolated atrial preparations was increased in aged mice but again showed high variability among age groups. HRV was correlated with FI score after ANS blockade and in isolated atrial preparations. CONCLUSION HRV is reduced in aging mice in association with a shift in sympathovagal balance and increased intrinsic SAN beating variability; however, HRV is highly variable within age groups. HRV was strongly correlated with frailty, which was able to detect differences in HRV separately from chronological age.
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Affiliation(s)
- Tristan W Dorey
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Hailey J Jansen
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Motahareh Moghtadaei
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - K Lockhart Jamieson
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Robert A Rose
- Libin Cardiovascular Institute, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
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29
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Howlett SE, Rutenberg AD, Rockwood K. The degree of frailty as a translational measure of health in aging. NATURE AGING 2021; 1:651-665. [PMID: 37117769 DOI: 10.1038/s43587-021-00099-3] [Citation(s) in RCA: 166] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 07/06/2021] [Indexed: 04/30/2023]
Abstract
Frailty is a multiply determined, age-related state of increased risk for adverse health outcomes. We review how the degree of frailty conditions the development of late-life diseases and modifies their expression. The risks for frailty range from subcellular damage to social determinants. These risks are often synergistic-circumstances that favor damage also make repair less likely. We explore how age-related damage and decline in repair result in cellular and molecular deficits that scale up to tissue, organ and system levels, where they are jointly expressed as frailty. The degree of frailty can help to explain the distinction between carrying damage and expressing its usual clinical manifestations. Studying people-and animals-who live with frailty, including them in clinical trials and measuring the impact of the degree of frailty are ways to better understand the diseases of old age and to establish best practices for the care of older adults.
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Affiliation(s)
- Susan E Howlett
- Geriatric Medicine Research Unit, Department of Medicine, Dalhousie University & Nova Scotia Health, Halifax, Nova Scotia, Canada
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Andrew D Rutenberg
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kenneth Rockwood
- Geriatric Medicine Research Unit, Department of Medicine, Dalhousie University & Nova Scotia Health, Halifax, Nova Scotia, Canada.
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30
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Kane AE, Howlett SE. Sex differences in frailty: Comparisons between humans and preclinical models. Mech Ageing Dev 2021; 198:111546. [PMID: 34324923 DOI: 10.1016/j.mad.2021.111546] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/18/2021] [Accepted: 07/22/2021] [Indexed: 02/07/2023]
Abstract
Frailty can be viewed as a state of physiological decline that increases susceptibility to adverse health outcomes. This loss of physiological reserve means that even small stressors can lead to disability and death in frail individuals. Frailty can be measured with various clinical tools; the two most popular are the frailty index and the frailty phenotype. Clinical studies have used these tools to show that women are frailer than men even though they have longer lifespans. Still, factors responsible for this frailty-mortality paradox are not well understood. This review highlights evidence for male-female differences in frailty from both the clinical literature and in animal models of frailty. We review evidence for higher frailty levels in female animals as seen in many preclinical models. Mechanisms that may contribute to sex differences in frailty are highlighted. In addition, we review work that suggests frailty may play a role in susceptibility to chronic diseases of aging in a sex-specific fashion. Additional mechanistic studies in preclinical models are needed to understand factors involved in male-female differences in frailty in late life.
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Affiliation(s)
- Alice E Kane
- Blavatnik Institute, Dept. of Genetics, Paul F. Glenn Center for Biology of Aging Research at Harvard Medical School, Boston, MA, United States.
| | - Susan E Howlett
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada; Department of Medicine (Geriatric Medicine), Dalhousie University, Halifax, NS, Canada.
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31
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Lee SR, Choi EK, Jung JH, Han KD, Oh S, Lip GYH. Lower risk of stroke after alcohol abstinence in patients with incident atrial fibrillation: a nationwide population-based cohort study. Eur Heart J 2021; 42:4759-4768. [PMID: 34097040 PMCID: PMC8651176 DOI: 10.1093/eurheartj/ehab315] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/21/2020] [Accepted: 05/14/2021] [Indexed: 01/18/2023] Open
Abstract
Aims The aim of this study was to evaluate the association between alcohol consumption status (and its changes) after newly diagnosed atrial fibrillation (AF) and the risk of ischaemic stroke. Methods and results Using the Korean nationwide claims and health examination database, we included subjects who were newly diagnosed with AF between 2010 and 2016. Patients were categorized into three groups according to the status of alcohol consumption before and after AF diagnosis: non-drinkers; abstainers from alcohol after AF diagnosis; and current drinkers. The primary outcome was incident ischaemic stroke during follow-up. Non-drinkers, abstainers, and current drinkers were compared using incidence rate differences after the inverse probability of treatment weighting (IPTW). Among a total of 97 869 newly diagnosed AF patients, 51% were non-drinkers, 13% were abstainers, and 36% were current drinkers. During 310 926 person-years of follow-up, 3120 patients were diagnosed with incident ischaemic stroke (10.0 per 1000 person-years). At 5-year follow-up, abstainers and non-drinkers were associated with a lower risk for stroke than current drinkers (incidence rate differences after IPTW, −2.03 [−3.25, −0.82] for abstainers and −2.98 [−3.81, −2.15] for non-drinkers, per 1000 person-years, respectively; and incidence rate ratios after IPTW, 0.75 [0.70, 0.81] for non-drinkers and 0.83 [0.74, 0.93] for abstainers, respectively). Conclusion Current alcohol consumption was associated with an increased risk of ischaemic stroke in patients with newly diagnosed AF, and alcohol abstinence after AF diagnosis could reduce the risk of ischaemic stroke. Lifestyle intervention, including attention to alcohol consumption, should be encouraged as part of a comprehensive approach to AF management to improve clinical outcomes.
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Affiliation(s)
- So-Ryoung Lee
- Department of Internal Medicine, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea
| | - Eue-Keun Choi
- Department of Internal Medicine, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea.,Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea
| | - Jin-Hyung Jung
- Department of Medical Statistics, College of Medicine, Catholic University of Korea, 222 Banpo-daero, Seoucho-gu, Seoul 06591, Republic of Korea
| | - Kyung-Do Han
- Statistics and Actuarial Science, Soongsil University, 369 Sangdo-ro, Dongjak-gu, Seoul 06978, Republic of Korea
| | - Seil Oh
- Department of Internal Medicine, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea.,Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea
| | - Gregory Y H Lip
- Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 03080, Republic of Korea.,Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Chest and Heart Hospital, Thomas Dr, Liverpool L14 3PE, UK.,Department of Clinical Medicine, Aalborg University, Aalborg 9000, Denmark
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32
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Jimenes DR, Teixeira Junior NR, Pereira AV, Berti JA, Barbosa CP, Sant'Ana DDMG. Human apoCIII transgenic mice with epicardial adipose tissue inflammation and PRESERVATION of the cardiac plexus. Exp Gerontol 2021; 148:111261. [PMID: 33647361 DOI: 10.1016/j.exger.2021.111261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 12/16/2020] [Accepted: 01/24/2021] [Indexed: 10/22/2022]
Abstract
Hypertriglyceridemia is a result of the increase in the serum levels of lipoproteins, which are responsible for the transport of triglycerides and can be caused by genetic and/or metabolic factors. Animal models which either express or lack genes related to changes in the lipoproteins profile are useful to understand lipid metabolism. Apolipoprotein CIII (apoCIII) is an important modulator of hepatic production and peripheral removal of triglycerides. Mice that overexpress the apoCIII gene become hypertriglyceridemic, showing high concentrations of free fatty acids in the blood. Since hypertriglyceridemia is related to atherosclerosis, and the latter refers to cardiac alterations, this study aimed at evaluating the morphological, morphometric and quantitative profiles of the cardiac plexus, as well as the morphometric and histopathological aspects of the epicardial adipose tissue in human apoCIII transgenic mice. Therefore, 8-12-month-old male C57BL/6 mice that overexpressed human apoCIII (CIII) and their respective controls were used. Our results showed that overexpression of human apoCIII did not modify morphological or quantitative parameters of cardiac plexus neurons; however, age increased both, the area and the number of such cells. Furthermore, there was a direct correlation of this dyslipidemia to the thickening of periganglionar type 1 collagens. On the other hand, this overexpression caused epicardial adipose tissue inflammation and an increase in the area of the adipocytes, thus, favoring the recruitment of inflammatory cells in this tissue. In conclusion, this overexpression is harmful since it is related to an increase in cardiac adiposity, as well as to a predisposition to an inflammatory environment in the epicardial fat and to the incidence of cardiovascular diseases.
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Affiliation(s)
- Diogo Rodrigues Jimenes
- Program of Graduate Studies in Bioscience and Physiopathology - State University of Maringá (PBF-UEM), Brazil.
| | | | | | | | | | - Débora de Mello Gonçales Sant'Ana
- Program of Graduate Studies in Bioscience and Physiopathology - State University of Maringá (PBF-UEM), Brazil; Department of Physiological Sciences (DFS-UEM), Brazil
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33
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Mishra M, Howlett SE. Preclinical models of frailty: Focus on interventions and their translational impact: A review. ACTA ACUST UNITED AC 2021. [DOI: 10.3233/nha-200103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The concept of frailty refers to heterogeneity in the risk of adverse outcomes for people of the same age. It is traditionally thought of as the inability of the body to maintain homeostasis. It can help explain differences between chronological and biological age and can quantify healthspan in experimental studies. Although clinical studies have developed tools to quantify frailty over the past two decades, preclinical models of frailty have only recently been introduced. This review describes the notion of frailty and outlines two commonly used clinical approaches to quantify frailty: the frailty phenotype and the frailty index. Translation of these methodologies for use in animals is introduced and studies that use these models to evaluate interventions designed to attenuate or exacerbate frailty are discussed. These include studies involving manipulation of diet, implementation of exercise regimens and tests of pharmaceutical agents to exacerbate or attenuate frailty. Together, this body of work suggests that preclinical frailty assessment tools are a valuable new resource to quantify the impact of interventions on overall health. Future studies could deploy these models to evaluate new frailty therapies, test combinations of interventions and assess interventions to enhance the ability to resist stressors in the setting of ageing.
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Affiliation(s)
- Manish Mishra
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Susan E. Howlett
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Medicine (Geriatric Medicine), Dalhousie University, Halifax, Nova Scotia, Canada
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34
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Age, Sex and Overall Health, Measured As Frailty, Modify Myofilament Proteins in Hearts From Naturally Aging Mice. Sci Rep 2020; 10:10052. [PMID: 32572088 PMCID: PMC7308399 DOI: 10.1038/s41598-020-66903-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 05/04/2020] [Indexed: 01/10/2023] Open
Abstract
We investigated effects of age, sex and frailty on contractions, calcium transients and myofilament proteins to determine if maladaptive changes associated with aging were sex-specific and modified by frailty. Ventricular myocytes and myofilaments were isolated from middle-aged (~12 mos) and older (~24 mos) mice. Frailty was assessed with a non-invasive frailty index. Calcium transients declined and slowed with age in both sexes, but contractions were largely unaffected. Actomyosin Mg-ATPase activity increased with age in females but not males; this could maintain contractions with smaller calcium transients in females. Phosphorylation of myosin-binding protein C (MyBP-C), desmin, tropomyosin and myosin light chain-1 (MLC-1) increased with age in males, but only MyBP-C and troponin-T increased in females. Enhanced phosphorylation of MyBP-C and MLC-1 could preserve contractions in aging. Interestingly, the age-related decline in Hill coefficients (r = −0.816; p = 0.002) and increase in phosphorylation of desmin (r = 0.735; p = 0.010), tropomyosin (r = 0.779; p = 0.005) and MLC-1 (r = 0.817; p = 0.022) were graded by the level of frailty in males but not females. In these ways, cardiac remodeling at cellular and subcellular levels is graded by overall health in aging males. Such changes may contribute to heart diseases in frail older males, whereas females may be resistant to these effects of frailty.
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35
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Keller K, Kane A, Heinze-Milne S, Grandy SA, Howlett SE. Chronic Treatment With the ACE Inhibitor Enalapril Attenuates the Development of Frailty and Differentially Modifies Pro- and Anti-inflammatory Cytokines in Aging Male and Female C57BL/6 Mice. J Gerontol A Biol Sci Med Sci 2020; 74:1149-1157. [PMID: 30256910 DOI: 10.1093/gerona/gly219] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Indexed: 11/13/2022] Open
Abstract
Studies on interventions that can delay or treat frailty in humans are limited. There is evidence of beneficial effects of angiotensin converting enzyme (ACE) inhibitors on aspects related to frailty, such as physical function, even in those without cardiovascular disease. This study aimed to longitudinally investigate the effect of an ACE inhibitor on frailty in aging male and female mice. Frailty was assessed with a clinical frailty index (FI) which quantifies health-related deficits in middle-aged (9-13 months) and older (16-25 months) mice. Chronic treatment with enalapril (30 mg/kg/day in feed) attenuated frailty in middle-aged and older female mice, and older male mice, without a long-term effect on blood pressure. Enalapril treatment resulted in a reduction in the proinflammatory cytokines interleukin (IL)-1α, monocyte chemoattractant protein-1 and macrophage inflammatory protein-1a in older female mice, and an increase in the anti-inflammatory cytokine IL-10 in older male mice compared with control animals. These sex-specific effects on inflammation may contribute to the protective effects of enalapril against frailty. This is the first study to examine the longitudinal effect of an intervention on the FI in mice, and provides preclinical evidence that enalapril may delay the onset of frailty, even when started later in life.
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Affiliation(s)
- Kaitlyn Keller
- Department of Pharmacology, Dalhousie University, Halifax, Canada
| | - Alice Kane
- Department of Pharmacology, Dalhousie University, Halifax, Canada
| | - Stefan Heinze-Milne
- School of Health and Human Performance, Dalhousie University, Halifax, Canada
| | - Scott A Grandy
- Department of Pharmacology, Dalhousie University, Halifax, Canada.,School of Health and Human Performance, Dalhousie University, Halifax, Canada
| | - Susan E Howlett
- Department of Pharmacology, Dalhousie University, Halifax, Canada.,Department of Medicine (Geriatric Medicine), Dalhousie University, Halifax, Canada
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36
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Jansen HJ, Bohne LJ, Gillis AM, Rose RA. Atrial remodeling and atrial fibrillation in acquired forms of cardiovascular disease. Heart Rhythm O2 2020; 1:147-159. [PMID: 34113869 PMCID: PMC8183954 DOI: 10.1016/j.hroo.2020.05.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Atrial fibrillation (AF) is prevalent in common conditions and acquired forms of heart disease, including diabetes mellitus (DM), hypertension, cardiac hypertrophy, and heart failure. AF is also prevalent in aging. Although acquired heart disease is common in aging individuals, age is also an independent risk factor for AF. Importantly, not all individuals age at the same rate. Rather, individuals of the same chronological age can vary in health status from fit to frail. Frailty can be quantified using a frailty index, which can be used to assess heterogeneity in individuals of the same chronological age. AF is thought to occur in association with electrical remodeling due to changes in ion channel expression or function as well as structural remodeling due to fibrosis, myocyte hypertrophy, or adiposity. These forms of remodeling can lead to triggered activity and electrical re-entry, which are fundamental mechanisms of AF initiation and maintenance. Nevertheless, the underlying determinants of electrical and structural remodeling are distinct in different conditions and disease states. In this focused review, we consider the factors leading to atrial electrical and structural remodeling in human patients and animal models of acquired cardiovascular disease or associated risk factors. Our goal is to identify similarities and differences in the cellular and molecular bases for atrial electrical and structural remodeling in conditions including DM, hypertension, hypertrophy, heart failure, aging, and frailty.
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Affiliation(s)
- Hailey J Jansen
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Loryn J Bohne
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Anne M Gillis
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Robert A Rose
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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Loss of insulin signaling may contribute to atrial fibrillation and atrial electrical remodeling in type 1 diabetes. Proc Natl Acad Sci U S A 2020; 117:7990-8000. [PMID: 32198206 DOI: 10.1073/pnas.1914853117] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Atrial fibrillation (AF) is prevalent in diabetes mellitus (DM); however, the basis for this is unknown. This study investigated AF susceptibility and atrial electrophysiology in type 1 diabetic Akita mice using in vivo intracardiac electrophysiology, high-resolution optical mapping in atrial preparations, and patch clamping in isolated atrial myocytes. qPCR and western blotting were used to assess ion channel expression. Akita mice were highly susceptible to AF in association with increased P-wave duration and slowed atrial conduction velocity. In a second model of type 1 DM, mice treated with streptozotocin (STZ) showed a similar increase in susceptibility to AF. Chronic insulin treatment reduced susceptibility and duration of AF and shortened P-wave duration in Akita mice. Atrial action potential (AP) morphology was altered in Akita mice due to a reduction in upstroke velocity and increases in AP duration. In Akita mice, atrial Na+ current (INa) and repolarizing K+ current (IK) carried by voltage gated K+ (Kv1.5) channels were reduced. The reduction in INa occurred in association with reduced expression of SCN5a and voltage gated Na+ (NaV1.5) channels as well as a shift in INa activation kinetics. Insulin potently and selectively increased INa in Akita mice without affecting IK Chronic insulin treatment increased INa in association with increased expression of NaV1.5. Acute insulin also increased INa, although to a smaller extent, due to enhanced insulin signaling via phosphatidylinositol 3,4,5-triphosphate (PIP3). Our study reveals a critical, selective role for insulin in regulating atrial INa, which impacts susceptibility to AF in type 1 DM.
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Kane AE, Keller KM, Heinze-Milne S, Grandy SA, Howlett SE. A Murine Frailty Index Based on Clinical and Laboratory Measurements: Links Between Frailty and Pro-inflammatory Cytokines Differ in a Sex-Specific Manner. J Gerontol A Biol Sci Med Sci 2019; 74:275-282. [PMID: 29788087 DOI: 10.1093/gerona/gly117] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Indexed: 12/12/2022] Open
Abstract
A frailty index (FI) based on clinical deficit accumulation (FI-Clinical) quantifies frailty in aging mice. We aimed to develop a laboratory test-based murine FI tool (FI-Lab) and to investigate the effects of age and sex on FI-Lab scores, FI-Clinical scores, and the combination (FI-Combined), as well as to explore links between frailty and inflammation. Studies used older (17 and 23 months) C57BL/6 mice of both sexes. We developed an FI-Lab (blood pressure, blood chemistry, echocardiography) based on deviation from reference values in younger adults (12 months), which showed similar characteristics to a human FI-Lab tool. Interestingly, while FI-Clinical scores were higher in females, the opposite was true for FI-Lab scores and there was no sex difference in FI-Combined scores. All three FI tools revealed a positive correlation between pro-inflammatory cytokine levels and frailty in aging mice that differed between the sexes. Elevated levels of the pro-inflammatory cytokines interleukin (IL)-6, IL-9, and interferon-γ were associated with higher FI scores in aging females, while levels of IL-12p40 rose as FI scores increased in older males. Thus, an FI tool based on common laboratory tests can quantify frailty in mice; the positive correlation between inflammation and frailty scores in naturally aging mice differs between the sexes.
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Affiliation(s)
- Alice E Kane
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Kaitlyn M Keller
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Stefan Heinze-Milne
- School of Health and Human Performance, Dalhousie University, Halifax, NS, Canada
| | - Scott A Grandy
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada.,School of Health and Human Performance, Dalhousie University, Halifax, NS, Canada
| | - Susan E Howlett
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada.,Department of Medicine (Geriatric Medicine), Dalhousie University, Halifax, NS, Canada
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Fibrosis independent atrial fibrillation in older patients is driven by substrate leukocyte infiltration: diagnostic and prognostic implications to patients undergoing cardiac surgery. J Transl Med 2019; 17:413. [PMID: 31822289 PMCID: PMC6905054 DOI: 10.1186/s12967-019-02162-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 11/28/2019] [Indexed: 12/11/2022] Open
Abstract
Background The objectives of the study were to characterize and quantify cellular inflammation and structural remodeling of human atria and correlate findings with molecular markers of inflammation and patient surrogate outcome. Methods Voluntary participants undergoing heart surgery were enrolled in the study and blood samples were collected prior to surgery, and right atrium samples were harvested intraoperatively. Blood samples were analyzed by flow cytometry and complete blood counts. Atrial samples were divided for fixed fibrosis analysis, homogenized for cytokine analysis and digested for single cell suspension flow cytometry. Results A total of 18 patients were enrolled and samples assessed. Isolated cells from the atria revealed a CD45+ population of ~ 20%, confirming a large number of leukocytes. Further characterization revealed this population as 57% lymphocytes and 26% monocyte/macrophages (MoΦ), with the majority of the latter cells being classical (CD14++/CD16−). Interstitial fibrosis was present in 87% of samples and correlated significantly with patient age. Older patients (> 65) had significantly more atrial fibrosis and cellular inflammation. AFib patients had no distinguishing feature of atrial fibrosis and had significantly greater CD45+ MoΦ, increased expression of MMP9 and presented with a significant correlation in length of stay to CCL-2/MCP-1 and NLR (neutrophil-to-lymphocyte ratio). Conclusion Atrial fibrosis is correlated with age and not determinate to AFib. However, severity of atrial leukocyte infiltration and markers of matrix degradation are determinant to AFib. This also correlated with CCL2 (or MCP-1) and NLR-indicative of marked inflammation. These data show the potential importance of diagnostic and prognostic assessments that could inform clinical decision making in regard to the intensity of AFib patient management.
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Wells SP, Waddell HM, Sim CB, Lim SY, Bernasochi GB, Pavlovic D, Kirchhof P, Porrello ER, Delbridge LMD, Bell JR. Cardiomyocyte functional screening: interrogating comparative electrophysiology of high-throughput model cell systems. Am J Physiol Cell Physiol 2019; 317:C1256-C1267. [PMID: 31577512 DOI: 10.1152/ajpcell.00306.2019] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cardiac arrhythmias of both atrial and ventricular origin are an important feature of cardiovascular disease. Novel antiarrhythmic therapies are required to overcome current drug limitations related to effectiveness and pro-arrhythmia risk in some contexts. Cardiomyocyte culture models provide a high-throughput platform for screening antiarrhythmic compounds, but comparative information about electrophysiological properties of commonly used types of cardiomyocyte preparations is lacking. Standardization of cultured cardiomyocyte microelectrode array (MEA) experimentation is required for its application as a high-throughput platform for antiarrhythmic drug development. The aim of this study was to directly compare the electrophysiological properties and responses to isoproterenol of three commonly used cardiac cultures. Neonatal rat ventricular myocytes (NRVMs), immortalized atrial HL-1 cells, and custom-generated human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were cultured on microelectrode arrays for 48-120 h. Extracellular field potentials were recorded, and conduction velocity was mapped in the presence/absence of the β-adrenoceptor agonist isoproterenol (1 µM). Field potential amplitude and conduction velocity were greatest in NRVMs and did not differ in cardiomyocytes isolated from male/female hearts. Both NRVMs and hiPSC-CMs exhibited longer field potential durations with rate dependence and were responsive to isoproterenol. In contrast, HL-1 cells exhibited slower conduction and shorter field potential durations and did not respond to 1 µM isoproterenol. This is the first study to compare the intrinsic electrophysiologic properties of cultured cardiomyocyte preparations commonly used for in vitro electrophysiology assessment. These findings offer important comparative data to inform methodological approaches in the use of MEA and other techniques relating to cardiomyocyte functional screening investigations of particular relevance to arrhythmogenesis.
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Affiliation(s)
- Simon P Wells
- Department of Physiology, School of Biomedical Sciences, University of Melbourne, Melbourne, Victoria, Australia.,Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, United Kingdom
| | - Helen M Waddell
- Department of Physiology, School of Biomedical Sciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Choon Boon Sim
- Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Shiang Y Lim
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia.,Departments of Medicine and Surgery, University of Melbourne, Melbourne, Victoria, Australia
| | - Gabriel B Bernasochi
- Department of Physiology, School of Biomedical Sciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Davor Pavlovic
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, United Kingdom
| | - Paulus Kirchhof
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, United Kingdom.,Departments of Cardiology, University Hospitals Birmingham and Sandwell and West Birmingham Hospitals National Health Service Trusts, Birmingham, United Kingdom
| | - Enzo R Porrello
- Department of Physiology, School of Biomedical Sciences, University of Melbourne, Melbourne, Victoria, Australia.,Murdoch Children's Research Institute, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Lea M D Delbridge
- Department of Physiology, School of Biomedical Sciences, University of Melbourne, Melbourne, Victoria, Australia
| | - James R Bell
- Department of Physiology, School of Biomedical Sciences, University of Melbourne, Melbourne, Victoria, Australia.,Department of Physiology, Anatomy and Microbiology, La Trobe University, Bundoora, Victoria, Australia
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Wilkinson MJ, Selman C, McLaughlin L, Horan L, Hamilton L, Gilbert C, Chadwick C, Flynn JN. Progressing the care, husbandry and management of ageing mice used in scientific studies. Lab Anim 2019; 54:225-238. [PMID: 31403890 PMCID: PMC7301645 DOI: 10.1177/0023677219865291] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Driven by the longer lifespans of humans, particularly in Westernised societies, and the need to know more about ‘healthy ageing’, ageing mice are being used increasingly in scientific research. Many departments and institutes involved with ageing research have developed their own systems to determine intervention points for potential refinements and to identify humane end points. Several good systems are in use, but variations between them could contribute to poor reproducibility of the science achieved. Working with scientific and regulatory communities in the UK, we have reviewed the clinical signs observed in ageing mice and developed recommendations for enhanced monitoring, behaviour assessment, husbandry and veterinary interventions. We advocate that the default time point for enhanced monitoring should be 15 months of age, unless prior information is available. Importantly, the enhanced monitoring should cause no additional harms to the animals. Where a mouse strain is well characterised, the onset of age-related enhanced monitoring may be modified based on knowledge of the onset of an expected age-related clinical sign. In progeroid models where ageing is accelerated, enhanced monitoring may need to be brought forward. Information on the background strain must be considered, as it influences the onset of age-related clinical signs. The range of ageing models currently used means that there will be no ‘one-size fits all’ solution. Increased awareness of the issues will lead to more refined and consistent husbandry of ageing mice, and application of humane end points will help to reduce the numbers of animals maintained for longer than is scientifically justified.
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Affiliation(s)
| | - Colin Selman
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, UK
| | | | - Linda Horan
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, UK
| | | | | | | | - J Norman Flynn
- Animals in Science Regulation Unit (ASRU), Home Office, UK
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Age-related deficit accumulation and the diseases of ageing. Mech Ageing Dev 2019; 180:107-116. [DOI: 10.1016/j.mad.2019.04.005] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/10/2019] [Accepted: 04/15/2019] [Indexed: 12/25/2022]
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Blodgett JM, Theou O, Mitnitski A, Howlett SE, Rockwood K. Associations between a laboratory frailty index and adverse health outcomes across age and sex. Aging Med (Milton) 2019; 2:11-17. [PMID: 31942508 PMCID: PMC6880698 DOI: 10.1002/agm2.12055] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 02/18/2019] [Accepted: 02/18/2019] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE Early frailty may be captured by a frailty index (FI) based entirely on vital signs and laboratory tests. Our aim was to examine associations between a laboratory-based FI (FI-Lab) and adverse health outcomes, and investigate how this changed with age. METHODS Up to 8988 individuals aged 20+ years from the 2003-2004 and 2005-2006 National Health and Nutrition Examination Survey cohorts were included. Characteristics of the FI-Lab were compared to those of a self-reported clinical FI. Associations between each FI and health care use, self-reported health, and disability were examined in the full sample and across age groups. RESULTS Laboratory-based FI scores increased with age but did not demonstrate expected sex differences. Women aged 20-39 years had higher FI scores than men; this pattern reversed after age 60 years. FI-Lab scores were associated with poor self-reported health (odds ratio[95% confidence interval]: 1.46[1.39-1.54]), high health care use (1.35[1.29-1.42]), and high disability (1.41[1.32-1.50]), even among those aged 20-39 years. CONCLUSION Higher FI-Lab scores were associated with poor health outcomes at all ages. Associations in the youngest group support the notion that deficit accumulation occurs across the lifespan. FI-Lab scores could be utilized as an early screening tool to identify deficit accumulation at the cellular and molecular level before they become clinically visible.
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Affiliation(s)
| | - Olga Theou
- Geriatric MedicineDepartment of MedicineDalhousie UniversityHalifaxNova ScotiaCanada
| | - Arnold Mitnitski
- Geriatric MedicineDepartment of MedicineDalhousie UniversityHalifaxNova ScotiaCanada
| | - Susan E. Howlett
- Geriatric MedicineDepartment of MedicineDalhousie UniversityHalifaxNova ScotiaCanada
- Department of PharmacologyDalhousie UniversityHalifaxNova ScotiaCanada
| | - Kenneth Rockwood
- Geriatric MedicineDepartment of MedicineDalhousie UniversityHalifaxNova ScotiaCanada
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Wallace LMK, Theou O, Godin J, Andrew MK, Bennett DA, Rockwood K. Investigation of frailty as a moderator of the relationship between neuropathology and dementia in Alzheimer's disease: a cross-sectional analysis of data from the Rush Memory and Aging Project. Lancet Neurol 2019; 18:177-184. [PMID: 30663607 PMCID: PMC11062500 DOI: 10.1016/s1474-4422(18)30371-5] [Citation(s) in RCA: 215] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 09/27/2018] [Accepted: 10/03/2018] [Indexed: 12/25/2022]
Abstract
BACKGROUND Some people with substantial Alzheimer's disease pathology at autopsy had shown few characteristic clinical symptoms or signs of the disease, whereas others with little Alzheimer's disease pathology have been diagnosed with Alzheimer's dementia. We aimed to examine whether frailty, which is associated with both age and dementia, moderates the relationship between Alzheimer's disease pathology and Alzheimer's dementia. METHODS We did a cross-sectional analysis of data from participants of the Rush Memory and Aging Project, a clinical-pathological cohort study of older adults (older than 59 years) without known dementia at baseline, living in Illinois, USA. Participants in the cohort study underwent annual neuropsychological and clinical evaluations. In the present cross-sectional analysis, we included those participants who did not have any form of dementia or who had Alzheimer's dementia at the time of their last clinical assessment and who had died and for whom complete autopsy data were available. Alzheimer's disease pathology was quantified by a summary measure of neurofibrillary tangles and neuritic and diffuse plaques. Clinical diagnosis of Alzheimer's dementia was based on clinician consensus. Frailty was operationalised retrospectively using health variable information obtained at each clincial evaluation using the deficit accumulation approach (41-item frailty index). Logistic regression and moderation modelling were used to assess relationships between Alzheimer's disease pathology, frailty, and Alzheimer's dementia. All analyses were adjusted for age, sex, and education. FINDINGS Up to data cutoff (Jan 20, 2017), we included 456 participants (mean age at death 89·7 years [SD 6·1]; 316 [69%] women). 242 (53%) had a diagnosis of possible or probable Alzheimer's dementia at their last clinical assessment. Frailty (odds ratio 1·76, 95% CI 1·54-2·02; p<0·0001) and Alzheimer's disease pathology (4·81, 3·31-7·01; p<0·0001) were independently associated with Alzheimer's dementia, after adjusting for age, sex, and education. When frailty was added to the model for the relationship between Alzheimer's disease pathology and Alzheimer's dementia, model fit improved (p<0·0001). There was a significant interaction between frailty and Alzheimer's disease pathology (odds ratio 0·73, 95% CI 0·57-0·94; pinteraction=0·015). People with an increased frailty score had a weakened direct link between Alzheimer's disease pathology and Alzheimer's dementia; that is, people with a low amount of frailty were better able to tolerate Alzheimer's disease pathology, whereas those with higher amounts of frailty were more likely both to have more Alzheimer's disease pathology and for it to be expressed as dementia. INTERPRETATION The degree of frailty among people of the same age modifies the association between Alzheimer's disease pathology and Alzheimer's dementia. That frailty is related to both odds of Alzheimer's dementia and disease expression has implications for clinical management, since individuals with even a low level of Alzheimer's disease pathology might be at risk for dementia if they have high amounts of frailty. Further research should assess how frailty and cognition change over time to better elucidate this complex relationship. FUNDING None.
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Affiliation(s)
- Lindsay M K Wallace
- Geriatric Medicine Research, Centre for Health Care of the Elderly, Nova Scotia Health Authority, Halifax, NS, Canada; Department of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Olga Theou
- Geriatric Medicine Research, Centre for Health Care of the Elderly, Nova Scotia Health Authority, Halifax, NS, Canada; Department of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Judith Godin
- Geriatric Medicine Research, Centre for Health Care of the Elderly, Nova Scotia Health Authority, Halifax, NS, Canada; Department of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Melissa K Andrew
- Geriatric Medicine Research, Centre for Health Care of the Elderly, Nova Scotia Health Authority, Halifax, NS, Canada; Department of Medicine, Dalhousie University, Halifax, NS, Canada
| | - David A Bennett
- Rush Alzheimer's Disease Center, Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA
| | - Kenneth Rockwood
- Geriatric Medicine Research, Centre for Health Care of the Elderly, Nova Scotia Health Authority, Halifax, NS, Canada; Department of Medicine, Dalhousie University, Halifax, NS, Canada.
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Banga S, Heinze-Milne SD, Howlett SE. Rodent models of frailty and their application in preclinical research. Mech Ageing Dev 2019; 179:1-10. [PMID: 30703384 DOI: 10.1016/j.mad.2019.01.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 01/25/2019] [Indexed: 12/21/2022]
Abstract
In clinical medicine, the concept of frailty is viewed as a state of high vulnerability to adverse health outcomes in people of the same age. Frailty is an important challenge because the loss of physiological reserve means that even minor stressors can lead to disability and death in those who are frail. Even so, the biology of frailty is not well understood. Rodent models of frailty are stimulating research into the biology of frailty. These pre-clinical models are based on "reverse-translation". Investigators have adapted either the "frailty phenotype" approach or the "frailty index" approach, originally developed in humans, for use in animals. This review briefly describes rodent models of frailty, discusses how these models have been used to explore mechanisms of frailty and how they have been employed to assess the impact of frailty on various experimental outcomes. The review also highlights studies that have used rodent models to investigate interventions to attenuate frailty, including drug treatment, dietary modifications and exercise. The ability to model frailty in animals is an exciting development that promises to accelerate the translation of laboratory discoveries into new clinical interventions, and situates frailty research in the larger context of geroscience.
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Affiliation(s)
- Shubham Banga
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada.
| | | | - Susan E Howlett
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada; Department of Medicine (Geriatric Medicine), Dalhousie University, Halifax, NS, Canada.
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Jansen HJ, Mackasey M, Moghtadaei M, Liu Y, Kaur J, Egom EE, Tuomi JM, Rafferty SA, Kirkby AW, Rose RA. NPR-C (Natriuretic Peptide Receptor-C) Modulates the Progression of Angiotensin II–Mediated Atrial Fibrillation and Atrial Remodeling in Mice. Circ Arrhythm Electrophysiol 2019; 12:e006863. [DOI: 10.1161/circep.118.006863] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Hailey J. Jansen
- Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (H.J.J., M. Mackasey, Y.L., J.K., A.W.K., R.A.R.), Cumming School of Medicine, University of Calgary, Alberta
- Department of Physiology and Pharmacology (H.J.J., M. Mackasey, Y.L., J.K., A.W.K., R.A.R.), Cumming School of Medicine, University of Calgary, Alberta
| | - Martin Mackasey
- Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (H.J.J., M. Mackasey, Y.L., J.K., A.W.K., R.A.R.), Cumming School of Medicine, University of Calgary, Alberta
- Department of Physiology and Pharmacology (H.J.J., M. Mackasey, Y.L., J.K., A.W.K., R.A.R.), Cumming School of Medicine, University of Calgary, Alberta
| | - Motahareh Moghtadaei
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia (M. Moghtadaei, E.E.E., S.A.R.)
| | - Yingjie Liu
- Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (H.J.J., M. Mackasey, Y.L., J.K., A.W.K., R.A.R.), Cumming School of Medicine, University of Calgary, Alberta
- Department of Physiology and Pharmacology (H.J.J., M. Mackasey, Y.L., J.K., A.W.K., R.A.R.), Cumming School of Medicine, University of Calgary, Alberta
| | - Jaspreet Kaur
- Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (H.J.J., M. Mackasey, Y.L., J.K., A.W.K., R.A.R.), Cumming School of Medicine, University of Calgary, Alberta
- Department of Physiology and Pharmacology (H.J.J., M. Mackasey, Y.L., J.K., A.W.K., R.A.R.), Cumming School of Medicine, University of Calgary, Alberta
| | - Emmanuel E. Egom
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia (M. Moghtadaei, E.E.E., S.A.R.)
| | - Jari M. Tuomi
- Department of Medicine, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada (J.M.T.)
| | - Sara A. Rafferty
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia (M. Moghtadaei, E.E.E., S.A.R.)
| | - Adam W. Kirkby
- Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (H.J.J., M. Mackasey, Y.L., J.K., A.W.K., R.A.R.), Cumming School of Medicine, University of Calgary, Alberta
- Department of Physiology and Pharmacology (H.J.J., M. Mackasey, Y.L., J.K., A.W.K., R.A.R.), Cumming School of Medicine, University of Calgary, Alberta
| | - Robert A. Rose
- Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta (H.J.J., M. Mackasey, Y.L., J.K., A.W.K., R.A.R.), Cumming School of Medicine, University of Calgary, Alberta
- Department of Physiology and Pharmacology (H.J.J., M. Mackasey, Y.L., J.K., A.W.K., R.A.R.), Cumming School of Medicine, University of Calgary, Alberta
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Abstract
The types of changes in physical appearance and behavior that occur in elderly people similarly develop in elderly animals. Signs and symptoms that might cause concern in younger people or mice may be normal in their elderly but generally healthy counterparts. Although numerous scoring methods have been developed to assess rodent health, these systems were often designed for young adults used in specific types of research, such as cancer or neurologic studies, and therefore may be suboptimal for assessing aging rodents. Approaches known as frailty assessments provide a global evaluation of the health of aged mice, rats, and people, and mouse frailty scores correlate well with the likelihood of death. Complementing frailty assessment, prediction of imminent death in aged mice can often be accomplished by focusing on 2 objective parameters-body weight and temperature. Before they die, many (but not all) mice develop marked reductions in body weight and temperature, thus providing signs that close monitoring, intervention, or preemptive euthanasia may be necessary. Timely preemptive euthanasia allows antemortem collection of data and samples that would be lost if spontaneous death occurred; preemptive euthanasia also limits terminal suffering. These approaches to monitoring declining health and predicting death in elderly research mice can aid in establishing and implementing timely interventions that both benefit the research and reduce antemortem suffering.
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Affiliation(s)
- Linda A Toth
- Emeritus Faculty, Southern Illinois University School of Medicine, Springfield, Illinois, USA.
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Stoyek MR, Rog-Zielinska EA, Quinn TA. Age-associated changes in electrical function of the zebrafish heart. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2018; 138:91-104. [DOI: 10.1016/j.pbiomolbio.2018.07.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 07/24/2018] [Accepted: 07/25/2018] [Indexed: 12/17/2022]
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Jansen HJ, Mackasey M, Moghtadaei M, Belke DD, Egom EE, Tuomi JM, Rafferty SA, Kirkby AW, Rose RA. Distinct patterns of atrial electrical and structural remodeling in angiotensin II mediated atrial fibrillation. J Mol Cell Cardiol 2018; 124:12-25. [PMID: 30273558 DOI: 10.1016/j.yjmcc.2018.09.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 09/25/2018] [Accepted: 09/26/2018] [Indexed: 01/14/2023]
Abstract
Atrial fibrillation (AF) is prevalent in hypertension and elevated angiotensin II (Ang II); however, the mechanisms by which Ang II leads to AF are poorly understood. Here, we investigated the basis for this in mice treated with Ang II or saline for 3 weeks. Ang II treatment increased susceptibility to AF compared to saline controls in association with increases in P wave duration and atrial effective refractory period, as well as reductions in right and left atrial conduction velocity. Patch-clamp studies demonstrate that action potential (AP) duration was prolonged in right atrial myocytes from Ang II treated mice in association with a reduction in repolarizing K+ currents. In contrast, APs in left atrial myocytes from Ang II treated mice showed reductions in upstroke velocity and overshoot, as well as greater prolongations in AP duration. Ang II reduced Na+ current (INa) in the left, but not the right atrium. This reduction in INa was reversible following inhibition of protein kinase C (PKC) and PKCα expression was increased selectively in the left atrium in Ang II treated mice. The transient outward K+ current (Ito) showed larger reductions in the left atrium in association with a shift in the voltage dependence of activation. Finally, Ang II caused fibrosis throughout the atria in association with changes in collagen expression and regulators of the extracellular matrix. This study demonstrates that hypertension and elevated Ang II cause distinct patterns of electrical and structural remodeling in the right and left atria that collectively create a substrate for AF.
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Affiliation(s)
- Hailey J Jansen
- Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Martin Mackasey
- Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Motahareh Moghtadaei
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Darrell D Belke
- Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Emmanuel E Egom
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jari M Tuomi
- Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada
| | - Sara A Rafferty
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Adam W Kirkby
- Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Robert A Rose
- Libin Cardiovascular Institute of Alberta, Department of Cardiac Sciences, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
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Laredo M, Waldmann V, Khairy P, Nattel S. Age as a Critical Determinant of Atrial Fibrillation: A Two-sided Relationship. Can J Cardiol 2018; 34:1396-1406. [PMID: 30404745 DOI: 10.1016/j.cjca.2018.08.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 07/23/2018] [Accepted: 08/01/2018] [Indexed: 12/19/2022] Open
Abstract
The incidence of atrial fibrillation (AF), the most common sustained arrhythmia and a major public health burden, increases exponentially with age. However, mechanisms underlying this long-recognized association remain incompletely understood. Experimental and human studies have demonstrated the involvement of aging in several arrhythmogenic processes, including atrial electrical and structural remodelling, disturbed calcium homeostasis, and enhanced atrial ectopic activity/increased vulnerability to re-entry induction. Given this wide range of putative mechanisms, the task of delineating the specific effects of aging responsible for AF promotion is not simple, as aging is itself associated with increasing prevalence of a host of AF-predisposing conditions, including heart failure, coronary artery disease, and hypertension. Although we usually think of old age promoting AF, there is also evidence that young age may actually have a protective effect against AF occurrence. For example, the low AF incidence among populations of young patients with significant structural congenital heart disease and substantial atrial enlargement/remodelling suggests that younger age might protect against fibrillation in the diseased atrium; efforts at understating how younger age may prevent AF might be helpful in elucidating missing mechanistic links between AF and age. The goal of this paper is to review the epidemiologic and pathophysiologic evidence regarding mechanisms underlying age-related AF. Although the therapeutic options for AF have recently improved, major gaps still remain and a better understanding of the special relationship between age and AF may be important for the identification of new targets for therapeutic innovation.
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Affiliation(s)
- Mikael Laredo
- Montreal Heart Institute, Université de Montréal, Montreal, Québec, Canada; AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Institut de Cardiologie, Paris, France
| | - Victor Waldmann
- Montreal Heart Institute, Université de Montréal, Montreal, Québec, Canada
| | - Paul Khairy
- Montreal Heart Institute, Université de Montréal, Montreal, Québec, Canada.
| | - Stanley Nattel
- Montreal Heart Institute, Université de Montréal, Montreal, Québec, Canada; Department of Pharmacology and Therapeutics, McGill University, Montreal, Québec, Canada; Institute of Pharmacology, University Duisburg-Essen, Essen, Germany; LIRYC Center, Bordeaux, France.
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