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Barry C, Rouhana S, Braun JL, Geromella MS, Fajardo VA, Pyle WG. Perimenopause Decreases SERCA2a Activity in the Hearts of a Mouse Model of Ovarian Failure. Biomolecules 2024; 14:675. [PMID: 38927078 PMCID: PMC11201532 DOI: 10.3390/biom14060675] [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: 05/12/2024] [Revised: 06/06/2024] [Accepted: 06/07/2024] [Indexed: 06/28/2024] Open
Abstract
Risk of cardiovascular disease mortality rises in women after menopause. While increased cardiovascular risk is largely attributed to postmenopausal declines in estrogens, the molecular changes in the heart that contribute to risk are poorly understood. Disruptions in intracellular calcium handling develop in ovariectomized mice and have been implicated in cardiac dysfunction. Using a mouse model of menopause in which ovarian failure occurs over 120 days, we sought to determine if perimenopause impacted calcium removal mechanisms in the heart and identify the molecular mechanisms. Mice were injected with 4-vinylcyclohexene diepoxide (VCD) to induce ovarian failure over 120 days, mimicking perimenopause. Hearts were removed at 60 and 120 days after VCD injections, representing the middle and end of perimenopause. SERCA2a function was significantly diminished at the end of perimenopause. Neither SERCA2a nor phospholamban expression changed at either time point, but phospholamban phosphorylation at S16 and T17 was dynamically altered. Intrinsic SERCA inhibitors sarcolipin and myoregulin increased >4-fold at day 60, as did the native activator DWORF. At the end of perimenopause, sarcolipin and myoregulin returned to baseline levels while DWORF was significantly reduced below controls. Sodium-calcium exchanger expression was significantly increased at the end of perimenopause. These results show that the foundation for increased cardiovascular disease mortality develops in the heart during perimenopause and that regulators of calcium handling exhibit significant fluctuations over time. Understanding the temporal development of cardiovascular risk associated with menopause and the underlying mechanisms is critical to developing interventions that mitigate the rise in cardiovascular mortality that arises after menopause.
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Affiliation(s)
- Ciara Barry
- IMPART Team Canada Investigator Network, Dalhousie Medicine, Saint John, NB E2K 5E2, Canada
| | - Sarah Rouhana
- IMPART Team Canada Investigator Network, Dalhousie Medicine, Saint John, NB E2K 5E2, Canada
| | - Jessica L. Braun
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada (V.A.F.)
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Mia S. Geromella
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada (V.A.F.)
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Val A. Fajardo
- Centre for Bone and Muscle Health, Brock University, St. Catharines, ON L2S 3A1, Canada (V.A.F.)
- Department of Kinesiology, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - W. Glen Pyle
- IMPART Team Canada Investigator Network, Dalhousie Medicine, Saint John, NB E2K 5E2, Canada
- Women’s Health Research Institute at BC Women’s Hospital + Health Centre, Vancouver, BC V6H 2N9, Canada
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Luo Y, Safabakhsh S, Palumbo A, Fiset C, Shen C, Parker J, Foster LJ, Laksman Z. Sex-Based Mechanisms of Cardiac Development and Function: Applications for Induced-Pluripotent Stem Cell Derived-Cardiomyocytes. Int J Mol Sci 2024; 25:5964. [PMID: 38892161 PMCID: PMC11172775 DOI: 10.3390/ijms25115964] [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: 05/06/2024] [Revised: 05/27/2024] [Accepted: 05/27/2024] [Indexed: 06/21/2024] Open
Abstract
Males and females exhibit intrinsic differences in the structure and function of the heart, while the prevalence and severity of cardiovascular disease vary in the two sexes. However, the mechanisms of this sex-based dimorphism are yet to be elucidated. Sex chromosomes and sex hormones are the main contributors to sex-based differences in cardiac physiology and pathophysiology. In recent years, the advances in induced pluripotent stem cell-derived cardiac models and multi-omic approaches have enabled a more comprehensive understanding of the sex-specific differences in the human heart. Here, we provide an overview of the roles of these two factors throughout cardiac development and explore the sex hormone signaling pathways involved. We will also discuss how the employment of stem cell-based cardiac models and single-cell RNA sequencing help us further investigate sex differences in healthy and diseased hearts.
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Affiliation(s)
- Yinhan Luo
- Centre for Heart Lung Innovation, Department of Medicine, University of British Columbia, Vancouver, BC V6Z 1Y6, Canada; (Y.L.); (J.P.)
| | - Sina Safabakhsh
- Centre for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, BC V6T 2A1, Canada;
| | - Alessia Palumbo
- Michael Smith Laboratories, Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (A.P.); (L.J.F.)
| | - Céline Fiset
- Research Centre, Montreal Heart Institute, Faculty of Pharmacy, Université de Montréal, Montréal, QC H1T 1C8, Canada;
| | - Carol Shen
- Department of Integrated Sciences, University of British Columbia, Vancouver, BC V6T 1Z2, Canada;
| | - Jeremy Parker
- Centre for Heart Lung Innovation, Department of Medicine, University of British Columbia, Vancouver, BC V6Z 1Y6, Canada; (Y.L.); (J.P.)
| | - Leonard J. Foster
- Michael Smith Laboratories, Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z4, Canada; (A.P.); (L.J.F.)
| | - Zachary Laksman
- Centre for Heart Lung Innovation, Department of Medicine, University of British Columbia, Vancouver, BC V6Z 1Y6, Canada; (Y.L.); (J.P.)
- Centre for Cardiovascular Innovation, Division of Cardiology, University of British Columbia, Vancouver, BC V6T 2A1, Canada;
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Heart Failure in Menopause: Treatment and New Approaches. Int J Mol Sci 2022; 23:ijms232315140. [PMID: 36499467 PMCID: PMC9735523 DOI: 10.3390/ijms232315140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/15/2022] [Accepted: 11/25/2022] [Indexed: 12/05/2022] Open
Abstract
Aging is an important risk factor for the development of heart failure (HF) and half of patients with HF have preserved ejection fraction (HFpEF) which is more common in elderly women. In general, sex differences that lead to discrepancies in risk factors and to the development of cardiovascular disease (CVD) have been attributed to the reduced level of circulating estrogen during menopause. Estrogen receptors adaptively modulate fibrotic, apoptotic, inflammatory processes and calcium homeostasis, factors that are directly involved in the HFpEF. Therefore, during menopause, estrogen depletion reduces the cardioprotection. Preclinical menopause models demonstrated that several signaling pathways and organ systems are closely involved in the development of HFpEF, including dysregulation of the renin-angiotensin system (RAS), chronic inflammatory process and alteration in the sympathetic nervous system. Thus, this review explores thealterations observed in the condition of HFpEF induced by menopause and the therapeutic targets with potential to interfere with the disease progress.
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Prajapati C, Koivumäki J, Pekkanen-Mattila M, Aalto-Setälä K. Sex differences in heart: from basics to clinics. Eur J Med Res 2022; 27:241. [PMID: 36352432 PMCID: PMC9647968 DOI: 10.1186/s40001-022-00880-z] [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: 10/17/2022] [Accepted: 10/24/2022] [Indexed: 11/11/2022] Open
Abstract
Sex differences exist in the structure and function of human heart. The patterns of ventricular repolarization in normal electrocardiograms (ECG) differ in men and women: men ECG pattern displays higher T-wave amplitude and increased ST angle. Generally, women have longer QT duration because of reduced repolarization reserve, and thus, women are more susceptible for the occurrence of torsades de pointes associated with drugs prolonging ventricular repolarization. Sex differences are also observed in the prevalence, penetrance and symptom severity, and also in the prognosis of cardiovascular disease. Generally, women live longer, have less clinical symptoms of cardiac diseases, and later onset of symptoms than men. Sex hormones also play an important role in regulating ventricular repolarization, suggesting that hormones directly influence various cellular functions and adrenergic regulation. From the clinical perspective, sex-based differences in heart physiology are widely recognized, but in daily practice, cardiac diseases are often underdiagnosed and untreated in the women. The underlying mechanisms of sex differences are, however, poorly understood. Here, we summarize sex-dependent differences in normal cardiac physiology, role of sex hormones, and differences in drug responses. Furthermore, we also discuss the importance of human induced pluripotent stem cell-derived cardiomyocytes in further understanding the mechanism of differences in women and men.
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Affiliation(s)
- Chandra Prajapati
- Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön Katu 34, 33520 Tampere, Finland
| | - Jussi Koivumäki
- Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön Katu 34, 33520 Tampere, Finland
| | - Mari Pekkanen-Mattila
- Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön Katu 34, 33520 Tampere, Finland
| | - Katriina Aalto-Setälä
- Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön Katu 34, 33520 Tampere, Finland
- Heart Center, Tampere University Hospital, Ensitie 4, 33520 Tampere, Finland
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Adekunle AO, Adzika GK, Mprah R, Ndzie Noah ML, Adu-Amankwaah J, Rizvi R, Akhter N, Sun H. Predominance of Heart Failure With Preserved Ejection Fraction in Postmenopausal Women: Intra- and Extra-Cardiomyocyte Maladaptive Alterations Scaffolded by Estrogen Deficiency. Front Cell Dev Biol 2021; 9:685996. [PMID: 34660569 PMCID: PMC8511782 DOI: 10.3389/fcell.2021.685996] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 09/09/2021] [Indexed: 12/11/2022] Open
Abstract
Heart failure (HF) remains a public health concern as it is associated with high morbidity and death rates. In particular, heart failure with preserved ejection fraction (HFpEF) represents the dominant (>50%) form of HF and mostly occurring among postmenopausal women. Hence, the initiation and progression of the left ventricular diastolic dysfunctions (LVDD) (a typically clinical manifestation of HFpEF) in postmenopausal women have been attributed to estrogen deficiency and the loss of its residue cardioprotective effects. In this review, from a pathophysiological and immunological standpoint, we discuss the probable multiple pathomechanisms resulting in HFpEF, which are facilitated by estrogen deficiency. The initial discussions recap estrogen and estrogen receptors (ERs) and β-adrenergic receptors (βARs) signaling under physiological/pathological states to facilitate cardiac function/dysfunction, respectively. By reconciling these prior discussions, attempts were made to explain how the loss of estrogen facilitates the disruptions both ERs and βARs-mediated signaling responsible for; the modulation of intra-cardiomyocyte calcium homeostasis, maintenance of cardiomyocyte cytoskeletal and extracellular matrix, the adaptive regulation of coronary microvascular endothelial functions and myocardial inflammatory responses. By scaffolding the disruption of these crucial intra- and extra-cardiomyocyte physiological functions, estrogen deficiency has been demonstrated to cause LVDD and increase the incidence of HFpEF in postmenopausal women. Finally, updates on the advancements in treatment interventions for the prevention of HFpEF were highlighted.
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Affiliation(s)
| | | | - Richard Mprah
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
| | | | | | | | - Nazma Akhter
- Department of Physiology, Xuzhou Medical University, Xuzhou, China
| | - Hong Sun
- Department of Physiology, Xuzhou Medical University, Xuzhou, China.,Xuzhou Medical University, Xuzhou, China
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Obesity-associated cardiovascular risk in women: hypertension and heart failure. Clin Sci (Lond) 2021; 135:1523-1544. [PMID: 34160010 DOI: 10.1042/cs20210384] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/14/2021] [Accepted: 06/07/2021] [Indexed: 02/07/2023]
Abstract
The pathogenesis of obesity-associated cardiovascular diseases begins long prior to the presentation of a cardiovascular event. In both men and women, cardiovascular events, and their associated hospitalizations and mortality, are often clinically predisposed by the presentation of a chronic cardiovascular risk factor. Obesity increases the risk of cardiovascular diseases in both sexes, however, the clinical prevalence of obesity, as well as its contribution to crucial cardiovascular risk factors is dependent on sex. The mechanisms via which obesity leads to cardiovascular risk is also discrepant in women between their premenopausal, pregnancy and postmenopausal phases of life. Emerging data indicate that at all reproductive statuses and ages, the presentation of a cardiovascular event in obese women is strongly associated with hypertension and its subsequent chronic risk factor, heart failure with preserved ejection fraction (HFpEF). In addition, emerging evidence indicates that obesity increases the risk of both hypertension and heart failure in pregnancy. This review will summarize clinical and experimental data on the female-specific prevalence and mechanisms of hypertension and heart failure in women across reproductive stages and highlight the particular risks in pregnancy as well as emerging data in a high-risk ethnicity in women of African ancestry (AA).
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Differing effects of estrogen deficiency on the contractile function of atrial and ventricular myocardium. Biochem Biophys Res Commun 2021; 541:30-35. [PMID: 33461065 DOI: 10.1016/j.bbrc.2020.12.102] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 12/30/2020] [Indexed: 11/20/2022]
Abstract
Estrogen deficiency has a significant influence on the excitation-contraction coupling in the ventricular myocardium but its impact on the atrial contractile function has not been studied. We have compared the effects of estrogen deficiency on the contractility and cytosolic Ca2+ transient of single cardiomyocytes isolated from the left atrium (LA) and the left ventricle (LV) of rats subjected to ovariectomy (OVX) or sham surgery (Sham). The characteristics of actin-myosin interaction were studied in an in vitro motility assay. We found that OVX decreased the contractility of LV single cardiomyocytes but increased that of LA myocytes. The disturbance of ventricular mechanical function may be explained by the acceleration of Ca2+ transient and reduced Ca2+ sensitivity of the actin-myosin interaction. The augmentation of LA contractility may be explained by accelerated cross-bridge kinetics and increased end-diastolic sarcomere length, which may lead to elevated tension in atrial cells due to the Frank-Starling mechanism.
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Firth JM, Yang HY, Francis AJ, Islam N, MacLeod KT. The Effect of Estrogen on Intracellular Ca 2+ and Na + Regulation in Heart Failure. ACTA ACUST UNITED AC 2020; 5:901-912. [PMID: 33015413 PMCID: PMC7524784 DOI: 10.1016/j.jacbts.2020.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 12/31/2022]
Abstract
During the progression toward heart failure, indicators of in vivo whole-heart function suggest greater impairment in the absence of estrogen. At the single cardiac myocyte level, the absence of estrogen results in further reduction of Ca2+ transient amplitudes, further slowing of transient decay kinetics, less SR Ca2+ content, and a further increase in Ca2+ spark frequencies and spark-mediated SR leak compared with animals with normal estrus cycles. Cardiac myocyte Na+ regulation is also more disrupted in the absence of estrogen.
Contradictory findings of estrogen supplementation in cardiac disease highlight the need to investigate the involvement of estrogen in the progression of heart failure in an animal model that lacks traditional comorbidities. Heart failure was induced by aortic constriction (AC) in female guinea pigs. Selected AC animals were ovariectomized (ACOV), and a group of these received 17β-estradiol supplementation (ACOV+E). One hundred-fifty days post-AC surgery, left-ventricular myocytes were isolated, and their electrophysiology and Ca2+ and Na+ regulation were examined. Long-term absence of ovarian hormones exacerbates the decline in cardiac function during the progression to heart failure. Estrogen supplementation reverses these aggravating effects.
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Key Words
- AC, aortic constriction
- ACOV+E, aortic constriction with ovariectomy, supplemented with 17β-estradiol
- ACOV, aortic constriction with ovariectomy
- FS, fractional shortening
- ICa, l-type Ca2+ channel current (cadmium-sensitive)
- INa,L, late Na+ current (ranolazine-sensitive)
- NCX, Na+/Ca2+ exchange
- OV, ovariectomy
- SERCA, Sarco/endoplasmic reticulum Ca2+-ATPase
- SR, sarcoplasmic reticulum
- calcium regulation
- cardiomyocytes
- estrogen
- excitation-contraction coupling
- female
- heart failure
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Affiliation(s)
- Jahn M Firth
- National Heart and Lung Institute, Imperial College, Hammersmith Hospital, London, United Kingdom
| | - Hsiang-Yu Yang
- Cardiovascular Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan (R.O.C.)
| | - Alice J Francis
- National Heart and Lung Institute, Imperial College, Hammersmith Hospital, London, United Kingdom
| | - Najah Islam
- National Heart and Lung Institute, Imperial College, Hammersmith Hospital, London, United Kingdom
| | - Kenneth T MacLeod
- National Heart and Lung Institute, Imperial College, Hammersmith Hospital, London, United Kingdom
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Is Cardiac Diastolic Dysfunction a Part of Post-Menopausal Syndrome? JACC-HEART FAILURE 2020; 7:192-203. [PMID: 30819374 DOI: 10.1016/j.jchf.2018.12.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 12/14/2018] [Accepted: 12/27/2018] [Indexed: 11/22/2022]
Abstract
Post-menopausal women exhibit an exponential increase in the incidence of heart failure with preserved ejection fraction compared with men of the same age, which indicates a potential role of hormonal changes in subclinical and clinical diastolic dysfunction. This paper reviews the preclinical evidence that demonstrates the involvement of estrogen in many regulatory molecular pathways of cardiac diastolic function and the clinical data that investigates the effect of estrogen on diastolic function in post-menopausal women. Published reports show that estrogen deficiency influences both early diastolic relaxation via calcium homeostasis and the late diastolic compliance associated with cardiac hypertrophy and fibrosis. Because of the high risk of diastolic dysfunction and heart failure with preserved ejection fraction in post-menopausal women and the positive effects of estrogen on preserving cardiac function, further clinical studies are needed to clarify the role of endogenous estrogen or hormone replacement in mitigating the onset and progression of heart failure with preserved ejection fraction in women.
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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: 4.3] [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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Ibañez AM, Espejo MS, Zavala MR, Villa-Abrille MC, Lofeudo JM, Aiello EA, De Giusti VC. Regulation of Intracellular pH is Altered in Cardiac Myocytes of Ovariectomized Rats. J Am Heart Assoc 2019; 8:e011066. [PMID: 30917747 PMCID: PMC6509710 DOI: 10.1161/jaha.118.011066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Background It is well known that after menopause women are exposed to a greater cardiovascular risk, but the intracellular modifications are not properly described. The sodium/proton exchanger (NHE) and the sodium/bicarbonate cotransporter (NBC) regulate the intracellular pH and, indirectly, the intracellular sodium concentration ([Na+]). There are 2 isoforms of NBC in the heart: the electrogenic (1Na+/2[Formula: see text]; NBCe1) and the electroneutral (1Na+/1[Formula: see text]; NBCn1). Because NHE and NBCn1 hyperactivity as well as the NBCe1 decreased activity have been associated with several cardiovascular pathologies, the aim of this study was to investigate the potential alterations of the alkalinizing transporters during the postmenopausal period. Methods and Results Three-month ovariectomized rats (OVX) were used. The NHE activity and protein expression are significantly increased in OVX. The NBCe1 activity is diminished, and the NBCn1 activity becomes predominant in OVX rats. p-Akt levels showed a significant diminution in OVX. Finally, NHE activity in platelets from OVX rats is also higher in comparison to sham rats, resulting in a potential biomarker of cardiovascular diseases. Conclusions Our results demonstrated for the first time that in the cardiac ventricular myocytes of OVX rats NHE and NBC isoforms are altered, probably because of the decreased level of p-Akt, compromising the ionic intracellular homeostasis.
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Affiliation(s)
- Alejandro Martín Ibañez
- 1 Centro de Investigaciones Cardiovasculares Facultad de Ciencias Médicas Universidad Nacional de La Plata-CONICET La Plata Argentina
| | - María Sofía Espejo
- 1 Centro de Investigaciones Cardiovasculares Facultad de Ciencias Médicas Universidad Nacional de La Plata-CONICET La Plata Argentina
| | - Maite Raquel Zavala
- 1 Centro de Investigaciones Cardiovasculares Facultad de Ciencias Médicas Universidad Nacional de La Plata-CONICET La Plata Argentina
| | - María Celeste Villa-Abrille
- 1 Centro de Investigaciones Cardiovasculares Facultad de Ciencias Médicas Universidad Nacional de La Plata-CONICET La Plata Argentina
| | - Juan Manuel Lofeudo
- 1 Centro de Investigaciones Cardiovasculares Facultad de Ciencias Médicas Universidad Nacional de La Plata-CONICET La Plata Argentina
| | - Ernesto Alejandro Aiello
- 1 Centro de Investigaciones Cardiovasculares Facultad de Ciencias Médicas Universidad Nacional de La Plata-CONICET La Plata Argentina
| | - Verónica Celeste De Giusti
- 1 Centro de Investigaciones Cardiovasculares Facultad de Ciencias Médicas Universidad Nacional de La Plata-CONICET La Plata Argentina
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Ayaz O, Banga S, Heinze-Milne S, Rose RA, Pyle WG, Howlett SE. Long-term testosterone deficiency modifies myofilament and calcium-handling proteins and promotes diastolic dysfunction in the aging mouse heart. Am J Physiol Heart Circ Physiol 2019; 316:H768-H780. [PMID: 30657724 DOI: 10.1152/ajpheart.00471.2018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The impact of long-term gonadectomy (GDX) on cardiac contractile function was explored in the setting of aging. Male mice were subjected to bilateral GDX or sham operation (4 wk) and investigated at 16-18 mo of age. Ventricular myocytes were field stimulated (2 Hz, 37°C). Peak Ca2+ transients (fura 2) and contractions were similar in GDX and sham-operated mice, although Ca2+ transients (50% decay time: 45.2 ± 2.3 vs. 55.6 ± 3.1 ms, P < 0.05) and contractions (time constant of relaxation: 39.1 ± 3.2 vs. 69.5 ± 9.3 ms, P < 0.05) were prolonged in GDX mice. Action potential duration was increased in myocytes from GDX mice, but this did not account for prolonged responses, as Ca2+ transient decay was slow even when cells from GDX mice were voltage clamped with simulated "sham" action potentials. Western blots of proteins involved in Ca2+ sequestration and efflux showed that Na+/Ca2+ exchanger and sarco(endo)plasmic reticulum Ca2+-ATPase type 2 protein levels were unaffected, whereas phospholamban was dramatically higher in ventricles from aging GDX mice (0.24 ± 0.02 vs. 0.86 ± 0.13, P < 0.05). Myofilament Ca2+ sensitivity at physiological Ca2+ was similar, but phosphorylation of essential myosin light chain 1 was reduced by ≈50% in ventricles from aging GDX mice. M-mode echocardiography showed no change in systolic function (e.g., ejection fraction). Critically, pulse-wave Doppler echocardiography showed that GDX slowed isovolumic relaxation time (12.9 ± 0.9 vs. 16.9 ± 1.0 ms, P < 0.05), indicative of diastolic dysfunction. Thus, dysregulation of intracellular Ca2+ and myofilament dysfunction contribute to deficits in contraction in hearts from testosterone-deficient aging mice. This suggests that low testosterone helps promote diastolic dysfunction in the aging heart. NEW & NOTEWORTHY The influence of long-term gonadectomy on contractile function was examined in aging male hearts. Gonadectomy slowed the decay of Ca2+ transients and contractions in ventricular myocytes and slowed isovolumic relaxation time, demonstrating diastolic dysfunction. Underlying mechanisms included Ca2+ dysregulation, elevated phospholamban protein levels, and hypophosphorylation of a myofilament protein, essential myosin light chain. Testosterone deficiency led to intracellular Ca2+ dysregulation and myofilament dysfunction, which may facilitate diastolic dysfunction in the setting of aging.
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Affiliation(s)
- Omar Ayaz
- Department of Pharmacology, Dalhousie University , Halifax, Nova Scotia , Canada
| | - Shubham Banga
- Department of Pharmacology, Dalhousie University , Halifax, Nova Scotia , Canada
| | - Stefan Heinze-Milne
- Department of Pharmacology, Dalhousie University , Halifax, Nova Scotia , Canada
| | - Robert A Rose
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary , Calgary, Alberta , Canada
| | - W Glen Pyle
- Department of Biomedical Sciences, University of Guelph , Guelph, Ontario , Canada
| | - Susan E Howlett
- Department of Pharmacology, Dalhousie University , Halifax, Nova Scotia , Canada.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary , Calgary, Alberta , Canada
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Mahmoodzadeh S, Dworatzek E. The Role of 17β-Estradiol and Estrogen Receptors in Regulation of Ca 2+ Channels and Mitochondrial Function in Cardiomyocytes. Front Endocrinol (Lausanne) 2019; 10:310. [PMID: 31156557 PMCID: PMC6529529 DOI: 10.3389/fendo.2019.00310] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 04/30/2019] [Indexed: 11/13/2022] Open
Abstract
Numerous epidemiological, clinical, and animal studies showed that cardiac function and manifestation of cardiovascular diseases (CVDs) are different between males and females. The underlying reasons for these sex differences are definitely multifactorial, but major evidence points to a causal role of the sex steroid hormone 17β-estradiol (E2) and its receptors (ER) in the physiology and pathophysiology of the heart. Interestingly, it has been shown that cardiac calcium (Ca2+) ion channels and mitochondrial function are regulated in a sex-specific manner. Accurate mitochondrial function and Ca2+ signaling are of utmost importance for adequate heart function and crucial to maintaining the cardiovascular health. Due to the highly sensitive nature of these processes in the heart, this review article highlights the current knowledge regarding sex dimorphisms in the heart implicating the importance of E2 and ERs in the regulation of cardiac mitochondrial function and Ca2+ ion channels, thus the contractility. In particular, we provide an overview of in-vitro and in-vivo studies using either E2 deficiency; ER deficiency or selective ER activation, which suggest that E2 and ERs are strongly involved in these processes. In this context, this review also discusses the divergent E2-responses resulting from the activation of different ER subtypes in these processes. Detailed understanding of the E2 and ER-mediated molecular and cellular mechanisms in the heart under physiological and pathological conditions may help to design more specifically targeted drugs for the management of CVDs in men and women.
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Affiliation(s)
- Shokoufeh Mahmoodzadeh
- Department of Molecular Muscle Physiology, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
- *Correspondence: Shokoufeh Mahmoodzadeh
| | - Elke Dworatzek
- Department of Molecular Muscle Physiology, Max-Delbrueck-Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
- Institute of Gender in Medicine, Charité Universitaetsmedizin, Berlin, Germany
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14
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Bernasochi GB, Boon WC, Delbridge LMD, Bell JR. The myocardium and sex steroid hormone influences. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2018.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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15
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Mathieu S, El Khoury N, Rivard K, Paradis P, Nemer M, Fiset C. Angiotensin II Overstimulation Leads to an Increased Susceptibility to Dilated Cardiomyopathy and Higher Mortality in Female Mice. Sci Rep 2018; 8:952. [PMID: 29343862 PMCID: PMC5772611 DOI: 10.1038/s41598-018-19436-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 11/15/2017] [Indexed: 11/09/2022] Open
Abstract
Heart failure (HF) is associated with high mortality and affects men and women differently. The underlying mechanisms for these sex-related differences remain largely unexplored. Accordingly, using mice with cardiac-specific overexpression of the angiotensin II (ANGII) type 1 receptor (AT1R), we explored male-female differences in the manifestations of hypertrophy and HF. AT1R mice of both sexes feature electrical and Ca2+ handling alterations, systolic dysfunction, hypertrophy and develop HF. However, females had much higher mortality (21.0%) rate than males (5.5%). In females, AT1R stimulation leads to more pronounced eccentric hypertrophy (larger increase in LV mass/body weight ratio [+31%], in cell length [+27%], in LV internal end-diastolic [LVIDd, +34%] and systolic [LVIDs, +67%] diameter) and dilation (larger decrease in LV posterior wall thickness, +17%) than males. In addition, in female AT1R mice the cytosolic Ca2+ extrusion mechanisms were more severely compromised and were associated with a specific increased in Ca2+ sparks (by 187%) and evidence of SR Ca2+ leak. Altogether, these results suggest that female AT1R mice have more severe eccentric hypertrophy, dysfunction and compromised Ca2+ dynamics. These findings indicate that females are more susceptible to the adverse effects of AT1R stimulation than males favouring the development of HF and increased mortality.
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Affiliation(s)
- Sophie Mathieu
- Research Center, Montreal Heart Institute, 5000 Bélanger, Montréal, Québec, Canada.,Faculty of Pharmacy, Université de Montréal, Montréal, Québec, Canada
| | - Nabil El Khoury
- Research Center, Montreal Heart Institute, 5000 Bélanger, Montréal, Québec, Canada.,Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Katy Rivard
- Research Center, Montreal Heart Institute, 5000 Bélanger, Montréal, Québec, Canada.,Faculty of Pharmacy, Université de Montréal, Montréal, Québec, Canada
| | - Pierre Paradis
- Lady Davis Institute, McGill University, Montreal, Québec, Canada
| | - Mona Nemer
- Ottawa University, Ottawa, Ontario, Canada
| | - Céline Fiset
- Research Center, Montreal Heart Institute, 5000 Bélanger, Montréal, Québec, Canada. .,Faculty of Pharmacy, Université de Montréal, Montréal, Québec, Canada.
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16
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Bernasochi GB, Boon WC, Curl CL, Varma U, Pepe S, Tare M, Parry LJ, Dimitriadis E, Harrap SB, Nalliah CJ, Kalman JM, Delbridge LM, Bell JR. Pericardial adipose and aromatase: A new translational target for aging, obesity and arrhythmogenesis? J Mol Cell Cardiol 2017; 111:96-101. [DOI: 10.1016/j.yjmcc.2017.08.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 08/01/2017] [Accepted: 08/14/2017] [Indexed: 10/19/2022]
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17
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Yang HY, Firth JM, Francis AJ, Alvarez-Laviada A, MacLeod KT. Effect of ovariectomy on intracellular Ca 2+ regulation in guinea pig cardiomyocytes. Am J Physiol Heart Circ Physiol 2017; 313:H1031-H1043. [PMID: 28778911 DOI: 10.1152/ajpheart.00249.2017] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/17/2017] [Accepted: 08/02/2017] [Indexed: 01/30/2023]
Abstract
This study addressed the hypothesis that long-term deficiency of ovarian hormones after ovariectomy (OVx) alters cellular Ca2+-handling mechanisms in the heart, resulting in the formation of a proarrhythmic substrate. It also tested whether estrogen supplementation to OVx animals reverses any alterations to cardiac Ca2+ handling and rescues proarrhythmic behavior. OVx or sham operations were performed on female guinea pigs using appropriate anesthetic and analgesic regimes. Pellets containing 17β-estradiol (1 mg, 60-day release) were placed subcutaneously in selected OVx animals (OVx + E). Cardiac myocytes were enzymatically isolated, and electrophysiological measurements were conducted with a switch-clamp system. In fluo-4-loaded cells, Ca2+ transients were 20% larger, and fractional sarcoplasmic reticulum (SR) Ca2+ release was 7% greater in the OVx group compared with the sham group. Peak L-type Ca2+ current was 16% larger in OVx myocytes with channel inactivation shifting to more positive membrane potentials, creating a larger "window" current. SR Ca2+ stores were 22% greater in the OVx group, and these cells showed a higher frequency of Ca2+ sparks and waves and shorter wave-free intervals. OVx myocytes showed higher frequencies of early afterdepolarizations, and a greater percentage of these cells showed delayed afterdepolarizations after exposure to isoprenaline compared with sham myocytes. The altered Ca2+ regulation occurring in the OVx group was not observed in the OVx + E group. These findings suggest that long-term deprivation of ovarian hormones in guinea pigs lead to changes in myocyte Ca2+-handling mechanisms that are considered proarrhythmogenic. 17β-Estradiol replacement prevented these adverse effects.NEW & NOTEWORTHY Ovariectomized guinea pig cardiomyocytes have higher frequencies of Ca2+ waves, and isoprenaline-challenged cells display more early afterdepolarizations, delayed afterdepolarizations, and extra beats compared with sham myocytes. These alterations to Ca2+ regulation were not observed in myocytes from ovariectomized guinea pigs supplemented with 17β-estradiol, suggesting that ovarian hormone deficiency modifies cardiac Ca2+ regulation, potentially creating proarrhythmic substrates.
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Affiliation(s)
- Hsiang-Yu Yang
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and.,Division of Cardiovascular Surgery, Department of Surgery, Tri-Service General Hospital, National Defence Medical Center, Taipei, Taiwan
| | - Jahn M Firth
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and
| | - Alice J Francis
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and
| | - Anita Alvarez-Laviada
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and
| | - Kenneth T MacLeod
- National Heart and Lung Institute, Imperial College London, London, United Kingdom; and
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18
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Parks RJ, Bogachev O, Mackasey M, Ray G, Rose RA, Howlett SE. The impact of ovariectomy on cardiac excitation-contraction coupling is mediated through cAMP/PKA-dependent mechanisms. J Mol Cell Cardiol 2017; 111:51-60. [PMID: 28778766 DOI: 10.1016/j.yjmcc.2017.07.118] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Revised: 07/11/2017] [Accepted: 07/28/2017] [Indexed: 12/18/2022]
Abstract
Ovariectomy (OVX) promotes sarcoplasmic reticulum (SR) Ca2+ overload in ventricular myocytes. We hypothesized that the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway contributes to this Ca2+ dysregulation. Myocytes were isolated from adult female C57BL/6 mice following either OVX or sham surgery (surgery at ≈1mos). Contractions, Ca2+ concentrations (fura-2) and ionic currents were measured simultaneously (37°C, 2Hz) in voltage-clamped myocytes. Intracellular cAMP levels were determined with an enzyme immunoassay; phosphodiesterase (PDE) and adenylyl cyclase (AC) isoform expression was examined with qPCR. Ca2+ currents were similar in myocytes from sham and OVX mice but Ca2+ transients, excitation-contraction (EC)-coupling gain, SR content and contractions were larger in OVX than sham cells. To determine if the cAMP/PKA pathway mediated OVX-induced alterations in EC-coupling, cardiomyocytes were incubated with the PKA inhibitor H-89 (2μM), which abolished baseline differences. While basal intracellular cAMP did not differ, levels were higher in OVX than sham in the presence of a non-selective PDE inhibitor (300μM IBMX), or an AC activator (10μM forskolin). This suggests the production of cAMP by AC and its breakdown by PDE were enhanced by OVX. Consistent with this, mRNA levels for both AC5 and PDE4A were higher in OVX in comparison to sham. Differences in Ca2+ homeostasis and contractions were abolished when sham and OVX cells were dialyzed with patch pipettes containing the same concentration of 8-bromoadenosine-cAMP (50μM). Interestingly, selective inhibition of PDE4 increased Ca2+ current only in OVX cells. Together, these findings suggest that estrogen suppresses SR Ca2+ release and that this is regulated, at least in part, by the cAMP/PKA pathway. These changes in the cAMP/PKA pathway may promote Ca2+ dysregulation and cardiovascular disease when ovarian estrogen levels fall. These results advance our understanding of female-specific cardiomyocyte mechanisms that may affect responses to therapeutic interventions in older women.
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Affiliation(s)
- Randi J Parks
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Oleg Bogachev
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Martin Mackasey
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Gibanananda Ray
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Robert A Rose
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
| | - Susan E Howlett
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada; Department of Medicine (Geriatric Medicine), Faculty of Medicine, Dalhousie University, 5850 College Street, P.O. Box 15000, Halifax B3H 4R2, Nova Scotia, Canada.
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19
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Murphy E, Amanakis G, Fillmore N, Parks RJ, Sun J. Sex Differences in Metabolic Cardiomyopathy. Cardiovasc Res 2017; 113:370-377. [PMID: 28158412 PMCID: PMC5852638 DOI: 10.1093/cvr/cvx008] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 12/19/2016] [Accepted: 01/16/2017] [Indexed: 12/23/2022] Open
Abstract
In contrast to ischemic cardiomyopathies which are more common in men, women are over-represented in diabetic cardiomyopathies. Diabetes is a risk factor for cardiovascular disease; however, there is a sexual dimorphism in this risk factor: heart disease is five times more common in diabetic women but only two-times more common in diabetic men. Heart failure with preserved ejection fraction, which is associated with metabolic syndrome, is also more prevalent in women. This review will examine potential mechanisms for the sex differences in metabolic cardiomyopathies. Sex differences in metabolism, calcium handling, nitric oxide, and structural proteins will be evaluated. Nitric oxide synthase and PPARα exhibit sex differences and have also been proposed to mediate the development of hypertrophy and heart failure. We focused on a role for these signalling pathways in regulating sex differences in metabolic cardiomyopathies.
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Affiliation(s)
- Elizabeth Murphy
- Systems Biology Center, National Heart, Lung and Blood Institute, NIH, MSC 1770, 10 Center Dr, Bethesda, MD 20892, USA
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20
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Regitz-Zagrosek V, Kararigas G. Mechanistic Pathways of Sex Differences in Cardiovascular Disease. Physiol Rev 2017; 97:1-37. [PMID: 27807199 DOI: 10.1152/physrev.00021.2015] [Citation(s) in RCA: 395] [Impact Index Per Article: 56.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Major differences between men and women exist in epidemiology, manifestation, pathophysiology, treatment, and outcome of cardiovascular diseases (CVD), such as coronary artery disease, pressure overload, hypertension, cardiomyopathy, and heart failure. Corresponding sex differences have been studied in a number of animal models, and mechanistic investigations have been undertaken to analyze the observed sex differences. We summarize the biological mechanisms of sex differences in CVD focusing on three main areas, i.e., genetic mechanisms, epigenetic mechanisms, as well as sex hormones and their receptors. We discuss relevant subtypes of sex hormone receptors, as well as genomic and nongenomic, activational and organizational effects of sex hormones. We describe the interaction of sex hormones with intracellular signaling relevant for cardiovascular cells and the cardiovascular system. Sex, sex hormones, and their receptors may affect a number of cellular processes by their synergistic action on multiple targets. We discuss in detail sex differences in organelle function and in biological processes. We conclude that there is a need for a more detailed understanding of sex differences and their underlying mechanisms, which holds the potential to design new drugs that target sex-specific cardiovascular mechanisms and affect phenotypes. The comparison of both sexes may lead to the identification of protective or maladaptive mechanisms in one sex that could serve as a novel therapeutic target in one sex or in both.
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Affiliation(s)
- Vera Regitz-Zagrosek
- Institute of Gender in Medicine & Center for Cardiovascular Research, Charite University Hospital, and DZHK (German Centre for Cardiovascular Research), Berlin, Germany
| | - Georgios Kararigas
- Institute of Gender in Medicine & Center for Cardiovascular Research, Charite University Hospital, and DZHK (German Centre for Cardiovascular Research), Berlin, Germany
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21
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Bell JR, Curl CL, Harding TW, Vila Petroff M, Harrap SB, Delbridge LMD. Male and female hypertrophic rat cardiac myocyte functional responses to ischemic stress and β-adrenergic challenge are different. Biol Sex Differ 2016; 7:32. [PMID: 27390618 PMCID: PMC4936311 DOI: 10.1186/s13293-016-0084-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 06/22/2016] [Indexed: 01/19/2023] Open
Abstract
Background Cardiac hypertrophy is the most potent cardiovascular risk factor after age, and relative mortality risk linked with cardiac hypertrophy is greater in women. Ischemic heart disease is the most common form of cardiovascular pathology for both men and women, yet significant differences in incidence and outcomes exist between the sexes. Cardiac hypertrophy and ischemia are frequently occurring dual pathologies. Whether the cellular (cardiomyocyte) mechanisms underlying myocardial damage differ in women and men remains to be determined. In this study, utilizing an in vitro experimental approach, our goal was to examine the proposition that responses of male/female cardiomyocytes to ischemic (and adrenergic) stress may be differentially modulated by the presence of pre-existing cardiac hypertrophy. Methods We used a novel normotensive custom-derived hypertrophic heart rat (HHR; vs control strain normal heart rat (NHR)). Cardiomyocyte morphologic and electromechanical functional studies were performed using microfluorimetric techniques involving simulated ischemia/reperfusion protocols. Results HHR females exhibited pronounced cardiac/cardiomyocyte enlargement, equivalent to males. Under basal conditions, a lower twitch amplitude in female myocytes was prominent in normal but not in hypertrophic myocytes. The cardiomyocyte Ca2+ responses to β-adrenergic challenge differed in hypertrophic male and female cardiomyocytes, with the accentuated response in males abrogated in females—even while contractile responses were similar. In simulated ischemia, a marked and selective elevation of end-ischemia Ca2+ in normal female myocytes was completely suppressed in hypertrophic female myocytes—even though all groups demonstrated similar shifts in myocyte contractile performance. After 30 min of simulated reperfusion, the Ca2+ desensitization characterizing the male response was distinctively absent in female cardiomyocytes. Conclusions Our data demonstrate that cardiac hypertrophy produces dramatically different basal and stress-induced pathophenotypes in female- and male-origin cardiomyocytes. The lower Ca2+ operational status characteristic of female (vs male) cardiomyocytes comprising normal hearts is not exhibited by myocytes of hypertrophic hearts. After ischemia/reperfusion, availability of activator Ca2+ is suppressed in female hypertrophic myocytes, whereas sensitivity to Ca2+ is blunted in male hypertrophic myocytes. These findings demonstrate that selective intervention strategies should be pursued to optimize post-ischemic electromechanical support for male and female hypertrophic hearts. Electronic supplementary material The online version of this article (doi:10.1186/s13293-016-0084-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- James R Bell
- Department of Physiology, University of Melbourne, Melbourne, Victoria Australia
| | - Claire L Curl
- Department of Physiology, University of Melbourne, Melbourne, Victoria Australia
| | - Tristan W Harding
- Department of Physiology, University of Melbourne, Melbourne, Victoria Australia
| | - Martin Vila Petroff
- Centro de Investigaciones Cardiovasculares, Centro Cientifico Tecnologico La Plata, Facultad de Ciencias Medicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Stephen B Harrap
- Department of Physiology, University of Melbourne, Melbourne, Victoria Australia
| | - Lea M D Delbridge
- Department of Physiology, University of Melbourne, Melbourne, Victoria Australia.,Cardiac Phenomics Laboratory, Department of Physiology, University of Melbourne, Melbourne, Victoria 3010 Australia
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22
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Alencar AK, da Silva JS, Lin M, Silva AM, Sun X, Ferrario CM, Cheng C, Sudo RT, Zapata-Sudo G, Wang H, Groban L. Effect of Age, Estrogen Status, and Late-Life GPER Activation on Cardiac Structure and Function in the Fischer344×Brown Norway Female Rat. J Gerontol A Biol Sci Med Sci 2016; 72:152-162. [PMID: 27006078 DOI: 10.1093/gerona/glw045] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 02/25/2016] [Indexed: 01/08/2023] Open
Abstract
Age-associated changes in cardiac structure and function, together with estrogen loss, contribute to the progression of heart failure with preserved ejection fraction in older women. To investigate the effects of aging and estrogen loss on the development of its precursor, asymptomatic left ventricular diastolic dysfunction, echocardiograms were performed in 10 middle-aged (20 months) and 30 old-aged (30 months) female Fischer344×Brown-Norway rats, 4 and 8 weeks after ovariectomy (OVX) and sham procedures (gonads left intact). The cardioprotective potential of administering chronic G1, the selective agonist to the new G-protein-coupled estrogen receptor (GPER), was further evaluated in old rats (Old-OVX+G1) versus age-matched, vehicle-treated OVX and gonadal intact rats. Advanced age and estrogen loss led to decreases in myocardial relaxation and elevations in filling pressure, in part, due to reductions in phosphorylated phospholamban and increases in cardiac collagen deposition. Eight weeks of G-protein-coupled estrogen receptor activation in Old-OVX+G1 rats reversed the adverse effects of age and estrogen loss on myocardial relaxation through increases in sarcoplasmic reticulum Ca2+ ATPase expression and reductions in interstitial fibrosis. These findings may explain the preponderance of heart failure with preserved ejection fraction in older postmenopausal women and provide a promising, late-life therapeutic target to reverse or halt the progression of left ventricular diastolic dysfunction.
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Affiliation(s)
- Allan K Alencar
- Department of Anesthesiology, Wake Forest School of Medicine, Winston-Salem, North Carolina.,Programa de Pesquisa em Desenvolvimento de Fármacos, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jaqueline S da Silva
- Programa de Pesquisa em Desenvolvimento de Fármacos, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marina Lin
- Department of Anesthesiology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Ananssa M Silva
- Programa de Pesquisa em Desenvolvimento de Fármacos, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Xuming Sun
- Department of Anesthesiology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Carlos M Ferrario
- Department of Internal Medicine, Section on Nephrology, Wake Forest School of Medicine, Winston-Salem, North Carolina.,Department of Surgery, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Cheping Cheng
- Department of Internal Medicine, Section on Cardiovascular Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Roberto T Sudo
- Programa de Pesquisa em Desenvolvimento de Fármacos, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Gisele Zapata-Sudo
- Programa de Pesquisa em Desenvolvimento de Fármacos, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Hao Wang
- Department of Anesthesiology, Wake Forest School of Medicine, Winston-Salem, North Carolina.,Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Leanne Groban
- Department of Anesthesiology, Wake Forest School of Medicine, Winston-Salem, North Carolina. .,Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina.,The Hypertension and Vascular Research Center, Wake Forest School of Medicine, Winston-Salem, North Carolina.,The Sticht Center on Aging, Wake Forest School of Medicine, Winston-Salem, North Carolina
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23
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Patel BB, Raad M, Sebag IA, Chalifour LE. Sex-specific cardiovascular responses to control or high fat diet feeding in C57bl/6 mice chronically exposed to bisphenol A. Toxicol Rep 2015; 2:1310-1318. [PMID: 28962473 PMCID: PMC5598525 DOI: 10.1016/j.toxrep.2015.09.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 09/25/2015] [Indexed: 12/16/2022] Open
Abstract
The increased pericardial fat which often accompanies overall obesity is thought to alter cardiac structure/function and increase the risk for atrial fibrillation. We hypothesized that chronic exposure to bisphenol A (BPA) would induce pericardial fat, cardiac hypertrophy or arrhythmia. C57bl/6n dams were exposed to BPA (25 ng/ml drinking water) beginning on gestation day 11 and progeny continued on 2.5 ng BPA/ml drinking water. The progeny of control dams (VEH) and dams treated with diethylstilbestrol (DES, 1 μg/kg/day, gestation days 1114) had tap water. After weaning progeny were fed either a control (CD) or high fat diet (HFD) for 3 months. Pericardial fat was present in CD-BPA and CD-DES and not CD-VEH mice, and was increased in all HFD mice. Catecholamine challenge revealed no differences in males, but BPA-exposed females had longer P-wave and QRS complex duration. Only CD-BPA and CD-DES females developed cardiac hypertrophy which was independent of increased blood pressure. Calcium homeostasis protein expression changes in HFD-BPA and HFD-DES mice predict reduced SERCA2 activity in males and increased SERCA2 activity in females. Thus, chronic BPA exposure induced pericardial fat in the absence of HFD, and female-specific changes in cardiac hypertrophy development and cardiac electrical conduction after a catecholamine challenge.
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Affiliation(s)
- Bhavini B Patel
- Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montreal, Quebec H3T 1E2, Canada
| | - Mohamad Raad
- Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montreal, Quebec H3T 1E2, Canada
| | - Igal A Sebag
- Division of Cardiology, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montreal, Quebec H3T 1E2, Canada
| | - Lorraine E Chalifour
- Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montreal, Quebec H3T 1E2, Canada.,Division of Cardiology, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montreal, Quebec H3T 1E2, Canada.,Division of Endocrinology, Jewish General Hospital, 3755 chemin Cote Ste Catherine, Montréal, Québec H3T 1E2, Canada.,Division of Experimental Medicine, Department of Medicine, McGill University, 850 Sherbrooke Street, Montréal, Québec H3A 1A2, Canada
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24
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Bell JR, Bernasochi GB, Wollermann AC, Raaijmakers AJA, Boon WC, Simpson ER, Curl CL, Mellor KM, Delbridge LMD. Myocardial and cardiomyocyte stress resilience is enhanced in aromatase-deficient female mouse hearts through CaMKIIδ activation. Endocrinology 2015; 156:1429-40. [PMID: 25625588 DOI: 10.1210/en.2014-1700] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The role of sex steroids in cardioprotection is contentious, with large clinical trials investigating hormone supplementation failing to deliver outcomes expected from observational studies. Mechanistic understanding of androgen/estrogen myocardial actions is lacking. Using a genetic model of aromatase tissue deficiency (ArKO) in female mice, the goal of this investigation was to evaluate the capacity of a shift in cardiac endogenous steroid conversion to influence ischemia-reperfusion resilience by optimizing cardiomyocyte Ca2+ handling responses. In isolated normoxic cardiomyocytes, basal Ca2+ transient amplitude and extent of shortening were greater in ArKO myocytes, with preservation of diastolic Ca2+ levels. Isolated ArKO cardiomyocytes exposed to a high Ca2+ load exhibited greater Ca2+ transient and contractile amplitudes, associated with a greater postrest spontaneous sarcoplasmic reticulum Ca2+ load-release. Microarray differential gene expression analysis of normoxic ventricular tissues from ArKO vs wild-type identified a significant influence of aromatase on genes involved in cardiac Ca2+ handling and signaling [including calmodulin dependent kinase II (CaMKII)-δ], myofilament structure and function, glucose uptake and signaling, and enzymes controlling phosphorylation-specific posttranslational modification status. CaMKII expression was not changed in ventricular tissues, although CaMKIIδ activation and phosphorylation of downstream targets was enhanced in ArKO hearts subjected to ischemia-reperfusion. Overall, this investigation shows that relative withdrawal of estrogen in favor of testosterone through genetically induced tissue aromatase deficiency in females modifies the gene expression profile to effect inotropic support via optimized Ca2+ handling in response to stress, with a modest impact on basal function. Consideration of aromatase inhibition, acutely or chronically, may have a role in cardioprotection, of particular relevance to women.
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Affiliation(s)
- James R Bell
- Cardiac Phenomics Laboratory (J.R.B., G.B.B., A.C.W., A.J.A.R., C.L.C., K.M.M., L.M.D.D.), Department of Physiology, and The Florey Institute of Neuroscience and Mental Health (W.C.B.), University of Melbourne, Victoria 3010, Australia; Monash Institute of Medical Research-Prince Henry's Institute of Medical Research (E.R.S.), Clayton 3168, Victoria, Australia; and Department of Physiology (K.M.M.), University of Auckland, 1142 Auckland, New Zealand
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25
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Bell JR, Raaijmakers AJ, Curl CL, Reichelt ME, Harding TW, Bei A, Ng DC, Erickson JR, Vila Petroff M, Harrap SB, Delbridge LM. Cardiac CaMKIIδ splice variants exhibit target signaling specificity and confer sex-selective arrhythmogenic actions in the ischemic-reperfused heart. Int J Cardiol 2015; 181:288-96. [DOI: 10.1016/j.ijcard.2014.11.159] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 10/24/2014] [Accepted: 11/23/2014] [Indexed: 01/16/2023]
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Kalász J, Tóth EP, Bódi B, Fagyas M, Tóth A, Pal BH, Vari SG, Balog M, Blažetić S, Heffer M, Papp Z, Borbély A. Single acute stress-induced progesterone and ovariectomy alter cardiomyocyte contractile function in female rats. Croat Med J 2014; 55:239-49. [PMID: 24891282 PMCID: PMC4049214 DOI: 10.3325/cmj.2014.55.239] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Aim To assess how ovarian-derived sex hormones (in particular progesterone) modify the effects of single acute stress on the mechanical and biochemical properties of left ventricular cardiomyocytes in the rat. Methods Non-ovariectomized (control, n = 8) and ovariectomized (OVX, n = 8) female rats were kept under normal conditions or were exposed to stress (control-S, n = 8 and OVX-S, n = 8). Serum progesterone levels were measured using a chemiluminescent immunoassay. Left ventricular myocardial samples were used for isometric force measurements and protein analysis. Ca2+-dependent active force (Factive), Ca2+-independent passive force (Fpassive), and Ca2+-sensitivity of force production were determined in single, mechanically isolated, permeabilized cardiomyocytes. Stress- and ovariectomy-induced alterations in myofilament proteins (myosin-binding protein C [MyBP-C], troponin I [TnI], and titin) were analyzed by sodium dodecyl sulfate gel electrophoresis using protein and phosphoprotein stainings. Results Serum progesterone levels were significantly increased in stressed rats (control-S, 35.6 ± 4.8 ng/mL and OVX-S, 21.9 ± 4.0 ng/mL) compared to control (10 ± 2.9 ng/mL) and OVX (2.8 ± 0.5 ng/mL) groups. Factive was higher in the OVX groups (OVX, 25.9 ± 3.4 kN/m2 and OVX-S, 26.3 ± 3.0 kN/m2) than in control groups (control, 16.4 ± 1.2 kN/m2 and control-S, 14.4 ± 0.9 kN/m2). Regarding the potential molecular mechanisms, Factive correlated with MyBP-C phosphorylation, while myofilament Ca2+-sensitivity inversely correlated with serum progesterone levels when the mean values were plotted for all animal groups. Fpassive was unaffected by any treatment. Conclusion Stress increases ovary-independent synthesis and release of progesterone, which may regulate Ca2+-sensitivity of force production in left ventricular cardiomyocytes. Stress and female hormones differently alter Ca2+-dependent cardiomyocyte contractile force production, which may have pathophysiological importance during stress conditions affecting postmenopausal women.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Attila Borbély
- Attila Borbély, University of Debrecen, Institute of Cardiology, Division of Clinical Physiology, Móricz Zsigmond krt. 22, H-4032 Debrecen, Hungary,
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Sex differences in SR Ca(2+) release in murine ventricular myocytes are regulated by the cAMP/PKA pathway. J Mol Cell Cardiol 2014; 75:162-73. [PMID: 25066697 DOI: 10.1016/j.yjmcc.2014.07.006] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 06/26/2014] [Accepted: 07/15/2014] [Indexed: 11/22/2022]
Abstract
Previous studies have shown that ventricular myocytes from female rats have smaller contractions and Ca(2+) transients than males. As cardiac contraction is regulated by the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway, we hypothesized that sex differences in cAMP contribute to differences in Ca(2+) handling. Ca(2+) transients (fura-2) and ionic currents were measured simultaneously (37°C, 2Hz) in ventricular myocytes from adult male and female C57BL/6 mice. Under basal conditions, diastolic Ca(2+), sarcoplasmic reticulum (SR) Ca(2+) stores, and L-type Ca(2+) current did not differ between the sexes. However, female myocytes had smaller Ca(2+) transients (26% smaller), Ca(2+) sparks (6% smaller), and excitation-contraction coupling gain in comparison to males (23% smaller). Interestingly, basal levels of intracellular cAMP were lower in female myocytes (0.7±0.1 vs. 1.7±0.2fmol/μg protein; p<0.001). Importantly, PKA inhibition (2μM H-89) eliminated male-female differences in Ca(2+) transients and gain, as well as Ca(2+) spark amplitude. Western blots showed that PKA inhibition also reduced the ratio of phospho:total RyR2 in male hearts, but not in female hearts. Stimulation of cAMP production with 10μM forskolin abolished sex differences in cAMP levels, as well as differences in Ca(2+) transients, sparks, and gain. To determine if the breakdown of cAMP differed between the sexes, phosphodiesterase (PDE) mRNA levels were measured. PDE3 expression was similar in males and females, but PDE4B expression was higher in female ventricles. The inhibition of cAMP breakdown by PDE4 (10μM rolipram) abolished differences in Ca(2+) transients and gain. These findings suggest that female myocytes have lower levels of basal cAMP due, in part, to higher expression of PDE4B. Lower cAMP levels in females may attenuate PKA phosphorylation of Ca(2+) handling proteins in females, and may limit positive inotropic responses to stimulation of the cAMP/PKA pathway in female hearts.
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MacDonald JK, Pyle WG, Reitz CJ, Howlett SE. Cardiac contraction, calcium transients, and myofilament calcium sensitivity fluctuate with the estrous cycle in young adult female mice. Am J Physiol Heart Circ Physiol 2014; 306:H938-53. [DOI: 10.1152/ajpheart.00730.2013] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
This study established conditions to induce regular estrous cycles in female C57BL/6J mice and investigated the impact of the estrous cycle on contractions, Ca2+ transients, and underlying cardiac excitation-contraction (EC)-coupling mechanisms. Daily vaginal smears from group-housed virgin female mice were stained to distinguish estrous stage (proestrus, estrus, metestrus, diestrus). Ventricular myocytes were isolated from anesthetized mice. Contractions and Ca2+ transients were measured simultaneously (4 Hz, 37°C). Interestingly, mice did not exhibit regular cycles unless they were exposed to male pheromones in bedding added to their cages. Field-stimulated myocytes from mice in estrus had larger contractions (∼2-fold increase), larger Ca2+ transients (∼1.11-fold increase), and longer action potentials (>2-fold increase) compared with other stages. Larger contractions and Ca2+ transients were not observed in estrus myocytes voltage-clamped with shorter action potentials. Voltage-clamp experiments also demonstrated that estrous stage had no effect on Ca2+ current, EC-coupling gain, diastolic Ca2+, sarcoplasmic reticulum (SR) Ca2+ content, or fractional release. Although contractions were largest in estrus, myofilament Ca2+ sensitivity was lowest (EC50 values ∼1.15-fold higher) in conjunction with increased phosphorylation of myosin binding protein C in estrus. Contractions were enhanced in ventricular myocytes from mice in estrus because action potential prolongation increased SR Ca2+ release. These findings demonstrate that cyclical changes in reproductive hormones associated with the estrous cycle can influence myocardial electrical and contractile function and modify Ca2+ homeostasis. However, such changes are unlikely to occur in female mice housed in groups under conventional conditions, since these mice do not exhibit regular estrous cycles.
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Affiliation(s)
| | - W. Glen Pyle
- Cardiovascular Research Group, Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada; and
| | - Cristine J. Reitz
- Cardiovascular Research Group, Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada; and
| | - 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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Fares E, Pyle WG, Ray G, Rose RA, Denovan-Wright EM, Chen RP, Howlett SE. The impact of ovariectomy on calcium homeostasis and myofilament calcium sensitivity in the aging mouse heart. PLoS One 2013; 8:e74719. [PMID: 24058623 PMCID: PMC3776741 DOI: 10.1371/journal.pone.0074719] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 08/05/2013] [Indexed: 12/20/2022] Open
Abstract
This study determined whether deficiency of ovarian estrogen starting very early in life promoted age-associated Ca(2+) dysregulation and contractile dysfunction in isolated ventricular myocytes. Myocytes were isolated from anesthetized C57BL/6 female mice. Animals received an ovariectomy or sham-operation at one month and were aged to ~24 months. Excitation-contraction coupling parameters were compared in fura-2 loaded myocytes (37°C). While Ca(2+) transients were larger and faster in field-stimulated myocytes from ovariectomized mice, ovariectomy had no effect on peak fractional shortening. Similarly, ovariectomy had no effect on fractional shortening measured in vivo by echocardiography (values were 60.5 ± 2.9 vs. 60.3 ± 2.5% in sham and ovariectomized, respectively; n=5 mice/group). Ovariectomy did decrease myofilament Ca(2+) sensitivity, as evidenced by a 26% increase in the Ca(2+) required to activate actomyosin MgATPase in ovariectomized hearts. Larger Ca(2+) transients were attributable to a 48% increase in peak Ca(2+) current, along with an increase in the amplitude, width and frequency of Ca(2+) sparks measured in fluo-4 loaded myocytes. These changes in Ca(2+) handling were not due to increased expression of Ca(2+) channels (Cav1.2), sarcoplasmic reticulum Ca(2+) ATPase (SERCA2) or Na(+)-Ca(2+) exchanger in ovariectomized hearts. However, ovariectomy increased sarcoplasmic reticulum Ca(2+) stores by ~90% and promoted spontaneous Ca(2+) release from the sarcoplasmic reticulum when compared to sham controls. These observations demonstrate that long-term ovariectomy promotes intracellular Ca(2+) dysregulation, reduces myofilament Ca(2+) sensitivity and increases spontaneous Ca(2+) release in the aging female heart.
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Affiliation(s)
- Elias Fares
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - W. Glen Pyle
- Cardiovascular Research Group, Department of Biomedical Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Gibanananda Ray
- Department of Physiology & Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Robert A. Rose
- Department of Physiology & Biophysics, Dalhousie University, Halifax, Nova Scotia, Canada
| | | | - Robert P. Chen
- Pediatric Cardiology, IWK Health Centre and 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
- * E-mail:
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Bell JR, Bernasochi GB, Varma U, Raaijmakers AJA, Delbridge LMD. Sex and sex hormones in cardiac stress--mechanistic insights. J Steroid Biochem Mol Biol 2013; 137:124-35. [PMID: 23770428 DOI: 10.1016/j.jsbmb.2013.05.015] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 05/28/2013] [Accepted: 05/29/2013] [Indexed: 01/14/2023]
Abstract
Important sex differences in the onset and characteristics of cardiovascular disease are evident, yet the mechanistic details remain unresolved. Men are more susceptible to cardiovascular disease earlier in life, though younger women who have a cardiovascular event are more likely to experience adverse outcomes. Emerging evidence is prompting a re-examination of the conventional view that estrogen is protective and testosterone a liability. The heart expresses both androgen and estrogen receptors and is functionally responsive to circulating sex steroids. New evidence of cardiac aromatase expression indicates local estrogen production may also exert autocrine/paracrine actions in the heart. Cardiomyocyte contractility studies suggest testosterone and estrogen have contrasting inotropic actions, and modulate Ca(2+) handling and transient characteristics. Experimentally, sex differences are also evident in cardiac stress responses. Female hearts are generally less susceptible to acute ischemic damage and associated arrhythmias, and generally are more resistant to stress-induced hypertrophy and heart failure, attributed to the cardioprotective actions of estrogen. However, more recent data show that testosterone can also improve acute post-ischemic outcomes and facilitate myocardial function and survival in chronic post-infarction. The myocardial actions of sex steroids are complex and context dependent. A greater mechanistic understanding of the specific actions of systemic/local sex steroids in different cardiovascular disease states has potential to lead to the development of cardiac therapies targeted specifically for men and women.
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Affiliation(s)
- James R Bell
- Department of Physiology, University of Melbourne, Victoria, Australia.
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Haddad R, Kasneci A, Sebag IA, Chalifour LE. Cardiac structure/function, protein expression, and DNA methylation are changed in adult female mice exposed to diethylstilbestrol in utero. Can J Physiol Pharmacol 2013; 91:741-9. [PMID: 23984849 DOI: 10.1139/cjpp-2013-0014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The detrimental effects of in utero exposure to the non-steroidal estrogen diethylstilbestrol (DES) are particularly marked in women. Fetal hearts express estrogen receptors, making them potentially responsive to DES. To examine whether gestational exposure to DES would impact the heart, we exposed pregnant C57bl/6n dams to DES (0.1, 1.0, and 10.0 μg·(kg body mass)(-1)·day(-1)) on gestation days 11.5-14.5, and examined the measured cardiac structure/function and calcium homeostasis protein expression in adult females. At baseline, echocardiography revealed eccentric hypertrophy in mice treated with 10.0 μg·(kg body mass)(-1)·day(-1) DES, and immunoblots showed increased SERCA2a in all DES-treated mice. Mice were swim-trained to assess cardiac remodeling. Swim-trained vehicle-treated mice developed eccentric hypertrophy without changing SERCA2 or calsequestrin 2 expression. In contrast, no DES-treated mice hypertrophied, and all increased in SERCA2a and calsequestrin 2 expression after training. To determine whether DES-induced changes in DNA methylation is part of the mechanism for its long-term effects, we measured DNA methyltransferase expression and DNA methylation. Global DNA methylation and DNA methyltransferase 3a expression were unchanged. However, DES-treated mice had increased DNA methylation in the calsequestrin 2 promoter. Thus, gestational exposure to DES altered female ventricular DNA, cardiac structure/function, and calcium homeostasis protein expression. We conclude that gestational exposure to estrogenizing compounds may impact cardiac structure/function in adult females.
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Affiliation(s)
- Rami Haddad
- Lady Davis Institute for Medical Research, Jewish General Hospital, 3755 chemin de la Côte Sainte Catherine, Montréal, QC H3T 1E2, Canada
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Sex differences in mechanisms of cardiac excitation-contraction coupling. Pflugers Arch 2013; 465:747-63. [PMID: 23417603 PMCID: PMC3651827 DOI: 10.1007/s00424-013-1233-0] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 01/29/2013] [Accepted: 01/30/2013] [Indexed: 11/25/2022]
Abstract
The incidence and expression of cardiovascular diseases differs between the sexes. This is not surprising, as cardiac physiology differs between men and women. Clinical and basic science investigations have shown important sex differences in cardiac structure and function. The pervasiveness of sex differences suggests that such differences must be fundamental, likely operating at a cellular level. Indeed, studies have shown that isolated ventricular myocytes from female animals have smaller and slower contractions and underlying calcium transients compared to males. Recent evidence suggests that this arises from sex differences in components of the cardiac excitation–contraction coupling pathway, the sequence of events linking myocyte depolarization to calcium release from the sarcoplasmic reticulum and subsequent contraction. The concept that sex hormones may regulate intracellular calcium at the level of the cardiomyocyte is important, as levels of these hormones decline in both men and women as the incidence of cardiovascular disease rises. This review focuses on the impact of sex on cardiac contraction, in particular at the cellular level, and highlights specific components of the excitation–contraction coupling pathway that differ between the sexes. Understanding sex hormone regulation of calcium homeostasis in the heart may reveal new avenues for therapeutic strategies to treat cardiac dysfunction and cardiovascular diseases.
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Haddad R, Kasneci A, Mepham K, Sebag IA, Chalifour LE. Gestational exposure to diethylstilbestrol alters cardiac structure/function, protein expression and DNA methylation in adult male mice progeny. Toxicol Appl Pharmacol 2013; 266:27-37. [DOI: 10.1016/j.taap.2012.10.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Revised: 10/19/2012] [Accepted: 10/23/2012] [Indexed: 01/03/2023]
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Parks RJ, Howlett SE. H-89 decreases the gain of excitation-contraction coupling and attenuates calcium sparks in the absence of beta-adrenergic stimulation. Eur J Pharmacol 2012; 691:163-72. [PMID: 22796673 DOI: 10.1016/j.ejphar.2012.07.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 06/27/2012] [Accepted: 07/03/2012] [Indexed: 01/11/2023]
Abstract
This study used the selective protein kinase A (PKA) inhibitor H-89 (N-[2-(p-Bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide) to determine the role of basal PKA activity in modulating cardiac excitation-contraction coupling in the absence of β-adrenergic stimulation. Basal intracellular cyclic AMP (cAMP) levels measured in isolated murine ventricular myocytes with an enzyme immunoassay were increased upon adenylyl cyclase activation (forskolin; 1 and 10 μM) or phosphodiesterase inhibition (3-isobutyl-1-methylxanthine, IBMX; 300 μM). Forskolin and IBMX also caused concentration-dependent increases in peak Ca(2+) transients (fura-2) and cell shortening (edge-detector) measured simultaneously in field-stimulated myocytes (37 °C). Similar effects were seen upon application of dibutyryl cAMP. In voltage-clamped myocytes, H-89 (2 μM) decreased basal Ca(2+) transients, contractions and underlying Ca(2+) currents. H-89 also decreased diastolic Ca(2+) and the gain of excitation-contraction coupling (Ca(2+) release/Ca(2+) current), especially at negative membrane potentials. This was independent of alterations in sarcoplasmic reticulum (SR) Ca(2+) loading, as SR stores were unchanged by PKA inhibition. H-89 also decreased the frequency, amplitude and width of spontaneous Ca(2+) sparks measured in quiescent myocytes (loaded with fluo-4), but increased time-to-peak. Thus, H-89 suppressed SR Ca(2+) release by decreasing Ca(2+) current and by reducing the gain of excitation-contraction coupling, in part by decreasing the size of individual Ca(2+) release units. These data suggest that basal PKA activity enhances SR Ca(2+) release in the absence of ß-adrenergic stimulation. This may depress contractile function in models such as aging, where the cAMP/PKA pathway is altered due to low basal cAMP levels.
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Affiliation(s)
- Randi J Parks
- Departments of Pharmacology, 1459 Oxford Street, PO Box 15000 Dalhousie University Halifax, Nova Scotia, Canada B3H 4R2.
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Ross JL, Howlett SE. Age and ovariectomy abolish beneficial effects of female sex on rat ventricular myocytes exposed to simulated ischemia and reperfusion. PLoS One 2012; 7:e38425. [PMID: 22701638 PMCID: PMC3368849 DOI: 10.1371/journal.pone.0038425] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Accepted: 05/09/2012] [Indexed: 12/24/2022] Open
Abstract
Sex differences in responses to myocardial ischemia have been described, but whether cardiomyocyte function is influenced by sex in the setting of ischemia and reperfusion has not been elucidated. This study compared contractions and intracellular Ca2+ in isolated ventricular myocytes exposed to ischemia and reperfusion. Cells were isolated from anesthetized 3-month-old male and female Fischer 344 rats, paced at 4 Hz (37°C), exposed to simulated ischemia (20 mins) and reperfused. Cell shortening (edge detector) and intracellular Ca2+ (fura-2) were measured simultaneously. Cell viability was assessed with Trypan blue. Ischemia reduced peak contractions and increased Ca2+ levels equally in myocytes from both sexes. However, contraction amplitudes were reduced in reperfusion in male myocytes, while contractions recovered to exceed control levels in females (62.6±5.1 vs. 140.1±15.8%; p<0.05). Only 60% of male myocytes excluded trypan blue dye after ischemia and reperfusion, while all female cardiomyocytes excluded the dye (p<0.05). Parallel experiments were conducted in myocytes from ∼24-month-old female rats or 5–6-month-old rats that had an ovariectomy at 3–4 weeks of age. Beneficial effects of female sex on myocyte viability and contractile dysfunction in reperfusion were abolished in cells from 24-month-old females. Aged female myocytes also exhibited elevated intracellular Ca2+ and alternans in ischemia. Cells from ovariectomized rats displayed increased Ca2+ transients and spontaneous activity in ischemia compared to sham-operated controls. None of the myocytes from ovariectomized rats were viable after 15 minutes of ischemia, while 75% of sham cells remained viable at end of reperfusion (p<0.05). These findings demonstrate that cardiomyocytes from young adult females are more resistant to ischemia and reperfusion injury than cells from males. Age and OVX abolish these beneficial effects and induce Ca2+ dysregulation at the level of the cardiomyocyte. Thus, beneficial effects of estrogen in ischemia and reperfusion are mediated, in part, by effects on cardiomyocytes.
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Affiliation(s)
- Jenna L. Ross
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Susan E. Howlett
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
- Division of Geriatric Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
- * E-mail:
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