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Kwan ED, Hardie BA, Garcia KM, Mu H, Wang TM, Valdez-Jasso D. Sex-dependent remodeling of right ventricular function in a rat model of pulmonary arterial hypertension. Am J Physiol Heart Circ Physiol 2024; 327:H351-H363. [PMID: 38847755 DOI: 10.1152/ajpheart.00098.2024] [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: 02/14/2024] [Revised: 05/09/2024] [Accepted: 05/29/2024] [Indexed: 07/17/2024]
Abstract
Right ventricular (RV) function is an important prognostic indicator for pulmonary arterial hypertension (PAH), a vasculopathy that primarily and disproportionally affects women with distinct pre- and postmenopausal clinical outcomes. However, most animal studies have overlooked the impact of sex and ovarian hormones on RV remodeling in PAH. Here, we combined invasive measurements of RV hemodynamics and morphology with computational models of RV biomechanics in sugen-hypoxia (SuHx)-treated male, ovary-intact female, and ovariectomized female rats. Despite similar pressure overload levels, SuHx induced increases in end-diastolic elastance and passive myocardial stiffening, notably in male SuHx animals, corresponding to elevated diastolic intracellular calcium. Increases in end-systolic chamber elastance were largely explained by myocardial hypertrophy in male and ovary-intact female rats, whereas ovariectomized females exhibited contractility recruitment via calcium transient augmentation. Ovary-intact female rats primarily responded with hypertrophy, showing fewer myocardial mechanical alterations and less stiffening. These findings highlight sex-related RV remodeling differences in rats, affecting systolic and diastolic RV function in PAH.NEW & NOTEWORTHY Combining hemodynamic and morphological measurements from male, female, and ovariectomized female pulmonary arterial hypertension (PAH) rats revealed distinct adaptation mechanisms despite similar pressure overload. Males showed the most diastolic stiffening. Ovariectomized females had enhanced myocyte contractility and calcium transient upregulation. Ovary-intact females primarily responded with hypertrophy, experiencing milder passive myocardial stiffening and no changes in myocyte shortening. These findings suggest potential sex-specific pathways in right ventricular (RV) adaptation to PAH, with implications for targeted interventions.
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MESH Headings
- Animals
- Female
- Male
- Ventricular Function, Right
- Ventricular Remodeling
- Disease Models, Animal
- Rats, Sprague-Dawley
- Ovariectomy
- Pulmonary Arterial Hypertension/physiopathology
- Pulmonary Arterial Hypertension/metabolism
- Pulmonary Arterial Hypertension/etiology
- Sex Factors
- Hypertrophy, Right Ventricular/physiopathology
- Hypertrophy, Right Ventricular/etiology
- Hypertrophy, Right Ventricular/metabolism
- Hypertrophy, Right Ventricular/pathology
- Rats
- Ventricular Dysfunction, Right/physiopathology
- Ventricular Dysfunction, Right/metabolism
- Ventricular Dysfunction, Right/etiology
- Pulmonary Artery/physiopathology
- Pulmonary Artery/metabolism
- Pulmonary Artery/pathology
- Models, Cardiovascular
- Calcium Signaling
- Hypertension, Pulmonary/physiopathology
- Hypertension, Pulmonary/metabolism
- Hypertension, Pulmonary/etiology
- Hemodynamics
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Affiliation(s)
- Ethan D Kwan
- Shu Chien-Gene Ley Department of BioengineeringUniversity of California, San Diego, La Jolla, California, United States
| | - Becky A Hardie
- Shu Chien-Gene Ley Department of BioengineeringUniversity of California, San Diego, La Jolla, California, United States
| | - Kristen M Garcia
- Shu Chien-Gene Ley Department of BioengineeringUniversity of California, San Diego, La Jolla, California, United States
| | - Hao Mu
- Shu Chien-Gene Ley Department of BioengineeringUniversity of California, San Diego, La Jolla, California, United States
| | - Tsui-Min Wang
- Shu Chien-Gene Ley Department of BioengineeringUniversity of California, San Diego, La Jolla, California, United States
| | - Daniela Valdez-Jasso
- Shu Chien-Gene Ley Department of BioengineeringUniversity of California, San Diego, La Jolla, California, United States
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2
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Investigation of doxorubicin combined with ciprofloxacin-induced cardiotoxicity: from molecular mechanism to fundamental heart function. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2022:10.1007/s00210-022-02331-2. [DOI: 10.1007/s00210-022-02331-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 11/07/2022] [Indexed: 11/25/2022]
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3
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Blawn KT, Kellohen KL, Galloway EA, Wahl J, Vivek A, Verkhovsky VG, Barker NK, Cottier KE, Vallecillo TG, Langlais PR, Liktor-Busa E, Vanderah TW, Largent-Milnes TM. Sex hormones regulate NHE1 functional expression and brain endothelial proteome to control paracellular integrity of the blood endothelial barrier. Brain Res 2021; 1763:147448. [PMID: 33771519 PMCID: PMC10494867 DOI: 10.1016/j.brainres.2021.147448] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 01/31/2023]
Abstract
BACKGROUND Sex hormones have been implicated in pH regulation of numerous physiological systems. One consistent factor of these studies is the sodium-hydrogen exchanger 1 (NHE1). NHE1 has been associated with pH homeostasis at epithelial barriers. Hormone fluctuations have been implicated in protection and risk for breaches in blood brain barrier (BBB)/blood endothelial barrier (BEB) integrity. Few studies, however, have investigated BBB/BEB integrity in neurological disorders in the context of sex-hormone regulation of pH homeostasis. METHODS//RESULTS Physiologically relevant concentrations of 17-β-estradiol (E2, 294 pM), progesterone (P, 100 nM), and testosterone (T,3.12 nM) were independently applied to cultured immortalized bEnd.3 brain endothelial cells to study the BEB. Individual gonadal hormones showed preferential effects on extracellular pH (E2), 14C-sucrose uptake (T), stimulated paracellular breaches (P) with dependence on functional NHE1 expression without impacting transendothelial resistance (TEER) or total protein expression. While total NHE1 expression was not changed as determined via whole cell lysate and subcellular fractionation experiment, biotinylation of NHE1 for surface membrane expression showed E2 reduced functional expression. Quantitative proteomic analysis revealed divergent effects of 17-β-estradiol and testosterone on changes in protein abundance in bEnd.3 endothelial cells as compared to untreated controls. CONCLUSIONS These data suggest that circulating levels of sex hormones may independently control BEB integrity by 1) regulating pH homeostasis through NHE1 functional expression and 2) modifying the endothelial proteome.
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Affiliation(s)
- Kiera T Blawn
- University of Arizona, Department of Pharmacology, Tucson, AZ, USA
| | | | - Emily A Galloway
- University of Arizona, Department of Pharmacology, Tucson, AZ, USA
| | - Jared Wahl
- University of Arizona, Department of Pharmacology, Tucson, AZ, USA
| | - Anjali Vivek
- University of Arizona, Department of Pharmacology, Tucson, AZ, USA
| | | | - Natalie K Barker
- University of Arizona, Department of Medicine, Division of Endocrinology, College of Medicine, Tucson, AZ, USA
| | | | | | - Paul R Langlais
- University of Arizona, Department of Medicine, Division of Endocrinology, College of Medicine, Tucson, AZ, USA
| | | | - Todd W Vanderah
- University of Arizona, Department of Pharmacology, Tucson, AZ, USA
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4
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Abstract
PURPOSE OF THE REVIEW This review summarizes sex-related changes in the heart and vasculature that occur with aging, both in the presence and absence of cardiovascular disease (CVD). RECENT FINDINGS In the presence of CVD risk factors and/or overt CVD, sex-specific changes in the number of cardiomyocytes, extent of the myocardial extracellular matrix, and myocellular hypertrophy promote unique patterns of LV remodeling in men and women. In addition, age- and sex-specific vascular stiffening is also well established, driven by changes in endothelial dysfunction, elastin-collagen content, microvascular dysfunction, and neurohormonal signaling. Together, these changes in LV chamber geometry and morphology, coupled with heightened vascular stiffness, appear to drive both age-related increases in systolic function and declines in diastolic function, particularly in postmenopausal women. Accordingly, estrogen has been implicated as a key mediator, given its direct vasodilating properties, association with nitric oxide excretion, and involvement in myocellular Ca2+ handling, mitochondrial energy production, and oxidative stress. The culmination of the abovementioned sex-specific cardiac and vascular changes across the lifespan provides important insight into heart failure development, particularly of the preserved ejection fraction variety, while offering promise for future preventive strategies and therapeutic approaches.
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Affiliation(s)
- Andrew Oneglia
- Applied Physiology and Advanced Imaging Lab, University of Texas at Arlington, 655 West Mitchell St, Arlington, TX, 76010, USA
| | - Michael D Nelson
- Applied Physiology and Advanced Imaging Lab, University of Texas at Arlington, 655 West Mitchell St, Arlington, TX, 76010, USA
- Barbra Streisand Women's Heart Center, Smidt Heart Institute, Cedars-Sinai Medical Center, 127 S San Vicente Blvd, AHSP Suite A3206, Los Angeles, CA, 90048, USA
| | - C Noel Bairey Merz
- Barbra Streisand Women's Heart Center, Smidt Heart Institute, Cedars-Sinai Medical Center, 127 S San Vicente Blvd, AHSP Suite A3206, Los Angeles, CA, 90048, USA.
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5
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Fernandes RD, Hall A, Ferguson M, Lorenzen‐Schmidt I, Balasubramaniam V, Pyle WG. Cardiac changes during the peri-menopausal period in a VCD-induced murine model of ovarian failure. Acta Physiol (Oxf) 2019; 227:e13290. [PMID: 31050200 PMCID: PMC7379283 DOI: 10.1111/apha.13290] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 04/25/2019] [Accepted: 04/26/2019] [Indexed: 01/30/2023]
Abstract
AIM Cardiovascular disease (CVD) risk is lower in pre-menopausal females vs age matched males. After menopause risk equals or exceeds that of males. CVD protection of pre-menopausal females is ascribed to high circulating oestrogen levels. Despite experimental evidence that oestrogen are cardioprotective, oestrogen replacement therapy trials have not shown clear benefits. One hypothesis to explain the discrepancy proposed hearts remodel during peri-menopause. Peri-menopasual myocardial changes have never been investigated, nor has the ability of oestrogen to regulate heart function during peri-menopause. METHODS We injected female mice with 4-vinylcyclohexene diepoxide (VCD, 160 mg/kg/d IP) to cause gradual ovarian failure over 120d and act as a peri-menopausal model RESULTS: Left ventricular function assessed by Langendorff perfusion found no changes in VCD-injected mice at 60 or 120 days compared to intact mice. Cardiac myofilament activity was altered at 60 and 120 days indicating a molecular remodelling in peri-menopause. Myocardial TGF-β1 increased at 60 days post-VCD treatment along with reduced Akt phosphorylation. Acute activation of oestrogen receptor-α (ERα) or -β (ERβ) depressed left ventricular contractility in hearts from intact mice. ER-regulation of myocardial and myofilament function, and myofilament phosphorylation, were disrupted in the peri-menopausal model. Disruption occurred without alterations in total ERα or ERβ expression. CONCLUSIONS This is the first study to demonstrate remodelling of the heart in a model of peri-menopause, along with a disruption in ER-dependent regulation of the heart. These data indicate that oestrogen replacement therapy initiated after menopause affects a heart that is profoundly different from that found in reproductively intact animals.
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Affiliation(s)
| | - Alexandra Hall
- Department of Biomedical Sciences University of Guelph Guelph Ontario Canada
| | - Melissa Ferguson
- Department of Biomedical Sciences University of Guelph Guelph Ontario Canada
| | | | | | - W. Glen Pyle
- Department of Biomedical Sciences University of Guelph Guelph Ontario Canada
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6
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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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7
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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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8
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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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9
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Rattanasopa C, Phungphong S, Wattanapermpool J, Bupha-Intr T. Significant role of estrogen in maintaining cardiac mitochondrial functions. J Steroid Biochem Mol Biol 2015; 147:1-9. [PMID: 25448746 DOI: 10.1016/j.jsbmb.2014.11.009] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 11/06/2014] [Accepted: 11/08/2014] [Indexed: 01/16/2023]
Abstract
Increased susceptibility to stress-induced myocardial damage is a significant concern in addition to decreased cardiac performance in postmenopausal females. To determine the potential mechanisms underlying myocardial vulnerability after deprivation of female sex hormones, cardiac mitochondrial function is determined in 10-week ovariectomized rats (OVX). Significant mitochondrial swelling in the heart of OVX rats is observed. This structural alteration can be prevented with either estrogen or progesterone supplementation. Using an isolated mitochondrial preparation, a decrease in ATP synthesis by complex I activation in an OVX rat is completely restored by estrogen, but not progesterone. At basal activation, reactive oxygen species (ROS) production from the mitochondria is not affected by the ovariectomy. However, after incubated in the presence of either high Ca(2+) or antimycin-A, there is a significantly higher mitochondrial ROS production in the OVX sample compared to the control. This increased stress-induced ROS production is not observed in the preparation isolated from the hearts of OVX rats with estrogen or progesterone supplementation. However, deprivation of female sex hormones has no effect on the protein expression of electron transport chain complexes, mitofusin 2, or superoxide dismutase 2. Taken together, these findings suggest that female sex hormones, estrogen and progesterone, play significant regulatory roles in maintaining normal mitochondrial properties by stabilizing the structural assembly of mitochondria as well as attenuating mitochondrial ROS production. Estrogen, but not progesterone, also plays an important role in modulating mitochondrial ATP synthesis.
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Affiliation(s)
- Chutima Rattanasopa
- Department of Physiology, Faculty of Science, Mahidol University, 272 Rama 6 Road, Bangkok, 10400 Thailand
| | - Sukanya Phungphong
- Department of Physiology, Faculty of Science, Mahidol University, 272 Rama 6 Road, Bangkok, 10400 Thailand
| | - Jonggonnee Wattanapermpool
- Department of Physiology, Faculty of Science, Mahidol University, 272 Rama 6 Road, Bangkok, 10400 Thailand
| | - Tepmanas Bupha-Intr
- Department of Physiology, Faculty of Science, Mahidol University, 272 Rama 6 Road, Bangkok, 10400 Thailand.
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10
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Yoshikawa T. Takotsubo cardiomyopathy, a new concept of cardiomyopathy: clinical features and pathophysiology. Int J Cardiol 2014; 182:297-303. [PMID: 25585367 DOI: 10.1016/j.ijcard.2014.12.116] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 12/26/2014] [Accepted: 12/28/2014] [Indexed: 12/11/2022]
Abstract
Takotsubo cardiomyopathy, a new concept of cardiomyopathy, is characterized by transient cardiac dysfunction, commonly triggered by physical or emotional stress. Differential diagnosis is important, since takotsubo cardiomyopathy presents similar images to those shown in acute coronary syndrome, with ST-segment elevation, T-wave inversion, QT-prolongation, and others on electrocardiogram. Typically, apical involvement with hypercontraction of basal left ventricle (apical type) is predominant, but atypical types involving basal, mid-ventricular, and right ventricular myocardium are also described. In-hospital death occurs at similar level with patients with acute coronary syndrome, but it is significantly affected by underlying diseases. This disease presents diverse cardiac complications in acute phase, such as life-threatening ventricular arrhythmias, pump failure, cardiac rupture, and systemic embolism. The pathogenic mechanism of this disease is still unclear but sympathetic hyperactivity, as well as coronary vasospasm, microcirculatory disorder, and estrogen deficiency, have been considered as one of the most likely pathogenic mechanism. Long-term prognosis is also largely unknown. Issues such as establishment of acute phase treatment, prediction of cardiac complications, and prophylactic measures against recurrence need to be further explored.
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Affiliation(s)
- Tsutomu Yoshikawa
- Department of Cardiology, Sakakibara Heart Institute, 3-16-1 Asahi-cho, Fuchu 183-0003, Japan.
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11
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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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12
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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: 25] [Impact Index Per Article: 2.3] [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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Abstract
Both clinical and experimental findings at the molecular, cellular, tissue, organ and systematic levels have depicted the presence of a contemporary regulatory machinery namely compensation in various forms of cardiovascular diseases. Compensation is believed to be present and regulated within the scope of a biological entity and represents the initiation of dyshomeostasis. Compensation can be identified in multiple categories and organs in cardiovascular diseases at multiple levels. The capacity to reduce the unfavorable pathological compensation may be a criterion to evaluate the therapeutic effectiveness for cardiovascular diseases. This mini-review tries to take compensation into consideration in the understanding of onset and progression of cardiovascular diseases in particular, and thus, better or optimal therapeutic approaches may be achieved for the prevention and management of cardiovascular diseases.
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Affiliation(s)
- Xiu-Juan Fan
- China Nepstar Chain Drugstore Ltd., Hangzhou 310003, Zhejiang, China.
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Wattanapermpool J, de Tombe PP, Pak TR. Sex differences in health and disease: brain and heart connections--a special issue. Pflugers Arch 2013; 465:555-6. [PMID: 23588381 DOI: 10.1007/s00424-013-1279-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 04/03/2013] [Indexed: 11/28/2022]
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15
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Kökçam SS, Tekin Ş, Kartal A, Ayaz M, Şahin M, Acar F, Çakir M, Küçükbağriaçik Y. Effect of sex steroids on soleus muscle response in hypocalcemic medium (in vitro). J Surg Res 2013; 185:883-8. [PMID: 23510550 DOI: 10.1016/j.jss.2013.02.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 01/25/2013] [Accepted: 02/16/2013] [Indexed: 10/27/2022]
Abstract
PURPOSE Postoperative hypocalcemia is a frequently encountered complication of thyroid surgery. Since hypocalcemic symptoms are closely associated with sex, the aim of this study is to investigate the effects of sex steroids on muscle tissue under hypocalcemic conditions. METHODS Six groups consisting of control male (M), control female (F), gonadectomized male (M-), gonadectomized female (F-), estradiol-applied gonadectomized male (MX), and testosterone-applied gonadectomized female (FX) rats were used. Contraction recordings were obtained from soleus muscle flaps. Maximal tension (PT), frequency required for 50% of PT (F50), contraction velocity at F50 (V50), and changes in contraction values (d[PT], d[F50], d[V50]) between normocalcemic and hypocalcemic conditions were calculated. RESULTS d[PT], d[F50], and d[V50] were significantly higher in M- and MX groups compared with control M group. Whereas d[PT], d[F50], and d[V50] parameters of the F- group were significantly higher than control F group, d[F50] and d[PT] of the FX group showed no significant change and d[V50] for the FX group was significantly lower. A comparison of control groups showed that d[PT], d[F50], and d[V50] of the F group were significantly higher than those of the M group. CONCLUSION Whereas absence of both testosterone and estradiol caused an increase in hypocalcemia-induced changes in contraction parameters of rat skeletal muscle, presence or application of testosterone clearly stabilized contraction parameters.
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Affiliation(s)
- S Said Kökçam
- Department of General Surgery, Konya Teaching and Research Hospital, Konya, Turkey.
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16
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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: 96] [Impact Index Per Article: 8.7] [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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Witayavanitkul N, Woranush W, Bupha-Intr T, Wattanapermpool J. Testosterone regulates cardiac contractile activation by modulating SERCA but not NCX activity. Am J Physiol Heart Circ Physiol 2013. [DOI: 10.1152/ajpheart.00555.2012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Alterations in intracellular Ca2+ transients of cardiomyocytes in orchidectomized (ORX) rats could be a cause of cardiac dysfunction in the hypogonadal condition. To investigate the role of male sex hormones in intracellular Ca2+ homeostasis during relaxation, Ca2+-handling activities by sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) and the Na+/Ca2+ exchanger (NCX) were evaluated in the ventricular muscle of 10-wk-old ORX rats with and without testosterone supplementation (2.5 mg/kg testosterone propionate, 2 times/wk). ORX induced a 50% decrease in contraction force accompanied by a prolonged time to achieve 50% relaxation ( T50) in isolated intact ventricular trabeculae, which was partially corrected by testosterone administration. Maximum active tension was also suppressed in ORX rats without changes in myofilament Ca2+ sensitivity and passive stiffness of the heart. Using a sarcoplasmic reticulum-enriched membrane preparation, the maximum thapsigargin-sensitive SERCA activity of the ORX rat was 27% lower with an increased Ca2+ sensitivity, which was prevented by testosterone treatment. However, neither changes in SERCA content nor its modulating components, sarcolipin and heat shock protein 20, were detected in the ORX rat, but there was a significant decrease in the phosphorylated Thr17 form of phospholamban. Despite a lower level of NCX protein in the heart of ORX rats, prolonged T50 disappeared after an incubation with thapsigargin (10 μM), implying a lack of effect of male sex hormone deficiency on NCX function. These findings indicate that male sex hormones can regulate cardiac relaxation by acting mainly through SERCA. However, a detailed mechanism of SERCA modulation under male sex hormone deficiency status remains to be explored.
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Affiliation(s)
| | - Warunya Woranush
- Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Tepmanas Bupha-Intr
- Department of Physiology, Faculty of Science, Mahidol University, Bangkok, Thailand
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18
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Fan XJ, Yu H, Ren J. Homeostasis and compensatory homeostasis: bridging Western medicine and traditional chinese medicine. Curr Cardiol Rev 2012; 7:43-6. [PMID: 22294974 PMCID: PMC3131715 DOI: 10.2174/157340311795677671] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 11/29/2010] [Accepted: 12/07/2010] [Indexed: 11/22/2022] Open
Abstract
Compensation is a self-protective mechanism in diseases, which may lead to a unique form of homeostasis deviates from that in physiological conditions. The kind of compensatory homeostasis can be embodied as various degrees accompanying disease progression (denoted as compensatory degree). Compensatory homeostasis provides a window for the transition from disease to healthy state. The causes of compensatory homeostasis themselves may be identified as targets for effective measures to eliminate compensation. Compensatory homeostasis embodies significantly mostly in the developing process of chronic diseases, which may help to explain in theory why intensive therapeutic strategies led to unexpected outcome in clinical practice. In addition, a large body of clinical evidence has valued traditional Chinese medicine (TCM), which is based on shifting compensatory homeostasis to the overall human body homeostasis, complementary to Western medicine in the management of chronic disease. In this review, we will briefly summarize the concept of compensation and attempt to bridge Western and traditional Chinese medicine through homeostasis and compensatory homeostasis based on an ample of evidence obtained from both disciplines
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Affiliation(s)
- Xiu-Juan Fan
- 1. China Nepstar Chain Drugstore Ltd., Hangzhou 310003 Zhejiang, China; 2. Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071, USA
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19
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Gender-specific effects of exercise on cardiac pathology in Na+/H+ exchanger overexpressing mice. Mol Cell Biochem 2012; 368:103-10. [DOI: 10.1007/s11010-012-1348-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 05/16/2012] [Indexed: 10/28/2022]
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20
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Curl CL, Bell JR, Delbridge LM. ‘Gain’-ful insight into the cardiomyocyte Ca2+ seX factor. J Mol Cell Cardiol 2012; 52:7-9. [DOI: 10.1016/j.yjmcc.2011.10.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 10/07/2011] [Indexed: 10/16/2022]
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21
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Fares E, Parks RJ, MacDonald JK, Egar JM, Howlett SE. Ovariectomy enhances SR Ca2+ release and increases Ca2+ spark amplitudes in isolated ventricular myocytes. J Mol Cell Cardiol 2012; 52:32-42. [DOI: 10.1016/j.yjmcc.2011.09.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Revised: 08/18/2011] [Accepted: 09/02/2011] [Indexed: 11/24/2022]
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22
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Ceylan-Isik AF, Li Q, Ren J. Insulin-like growth factor I (IGF-1) deficiency ameliorates sex difference in cardiac contractile function and intracellular Ca(2+) homeostasis. Toxicol Lett 2011; 206:130-8. [PMID: 21763763 PMCID: PMC3163688 DOI: 10.1016/j.toxlet.2011.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2011] [Revised: 06/30/2011] [Accepted: 07/01/2011] [Indexed: 11/26/2022]
Abstract
Sex difference in cardiac contractile function exists which may contribute to the different prevalence in cardiovascular diseases between genders. However, the precise mechanisms of action behind sex difference in cardiac function are still elusive. Given that sex difference exists in insulin-like growth factor I (IGF-1) cascade, this study is designed to evaluate the impact of severe liver IGF-1 deficiency (LID) on sex difference in cardiac function. Echocardiographic, cardiomyocyte contractile and intracellular Ca(2+) properties were evaluated including ventricular geometry, fractional shortening, peak shortening, maximal velocity of shortening/relengthening (±dL/dt), time-to-peak shortening (TPS), time-to-90% relengthening (TR(90)), fura-fluorescence intensity (FFI) and intracellular Ca(2+) clearance. Female C57 mice exhibited significantly higher plasma IGF-1 levels than their male counterpart. LID mice possessed comparably low IGF-1 levels in both sexes. Female C57 and LID mice displayed lower body, heart and liver weights compared to male counterparts. Echocardiographic analysis revealed larger LV mass in female C57 but not LID mice without sex difference in other cardiac geometric indices. Myocytes from female C57 mice exhibited reduced peak shortening, ±dL/dt, longer TPS, TR(90) and intracellular Ca(2+) clearance compared with males. Interestingly, this sex difference was greatly attenuated or abolished by IGF-1 deficiency. Female C57 mice displayed significantly decreased mRNA and protein levels of Na(+)-Ca(2+) exchanger, SERCA2a and phosphorylated phospholamban as well as SERCA activity compared with male C57 mice. These sex differences in Ca(2+) regulatory proteins were abolished or overtly attenuated by IGF-1 deficiency. In summary, our data suggested that IGF-1 deficiency may significantly attenuated or mitigate the sex difference in cardiomyocyte contractile function associated with intracellular Ca(2+) regulation.
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Affiliation(s)
- Asli F Ceylan-Isik
- Center for Cardiovascular Research and Alternative Medicine, School of Pharmacy, University of Wyoming College of Health Sciences, Laramie, WY 82071, USA
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23
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Sebag IA, Gillis MA, Calderone A, Kasneci A, Meilleur M, Haddad R, Noiles W, Patel B, Chalifour LE. Sex hormone control of left ventricular structure/function: mechanistic insights using echocardiography, expression, and DNA methylation analyses in adult mice. Am J Physiol Heart Circ Physiol 2011; 301:H1706-15. [DOI: 10.1152/ajpheart.00088.2011] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Calcium flux into and out of the sarco(endo)plasmic reticulum is vitally important to cardiac function because the cycle of calcium entry and exit controls contraction and relaxation. Putative estrogen and androgen consensus binding sites near to a CpG island are present in the cardiac calsequestrin 2 (CSQ2) promoter. Cardiomyocytes express sex hormone receptors and respond to sex hormones. We hypothesized that sex hormones control CSQ2 expression in cardiomyocytes and so affect cardiac structure/function. Echocardiographic analysis of male and female C57bl6n mice identified thinner walled and lighter hearts in females and significant concentric remodeling after long-term gonadectomy. CSQ2 and sodium-calcium exchanger-1 (NCX1) expression was significantly increased in female compared with male hearts and decreased postovariectomy. NCX1, but not CSQ2, expression was increased postcastration. CSQ2 expression was reduced when H9c2 cells were cultured in hormone-deficient media; increased when estrogen receptor-α (ERα), estrogen receptor-β (ERβ), or androgen agonists were added; and increased in hearts from ERβ-deficient mice. CSQ2 expression was reduced in mice fed a diet low in the methyl donor folic acid and in cells treated with 5-azadeoxycytidine suggesting an involvement of DNA methylation. DNA methylation in CpG in the CSQ2 CpG island was significantly different in males and females and was additionally changed postgonadectomy. Expression of DNA methyltransferases 1, 3a, and 3b was unchanged. These studies strongly link sex hormone-directed changes in CSQ2 expression to DNA methylation with changed expression correlated with altered left ventricular structure and function.
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Affiliation(s)
- Igal A. Sebag
- Division of Cardiology, Sir Mortimer B. Davis-Jewish General Hospital
| | - Marc-Antoine Gillis
- Institut du Cardiologie de Montréal et le Départements de Physiologie et Pharmacologie, Université de Montréal
| | - Angelino Calderone
- Institut du Cardiologie de Montréal et le Départements de Physiologie et Pharmacologie, Université de Montréal
| | - Amanda Kasneci
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital; and
| | - Melissa Meilleur
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital; and
| | - Rami Haddad
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital; and
| | - William Noiles
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital; and
| | - Bhavini Patel
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital; and
| | - Lorraine E. Chalifour
- Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital; and
- Division of Experimental Medicine, Department of Medicine, McGill University, Montréal, Québec
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Bupha-Intr T, Oo YW, Wattanapermpool J. Increased myocardial stiffness with maintenance of length-dependent calcium activation by female sex hormones in diabetic rats. Am J Physiol Heart Circ Physiol 2011; 300:H1661-8. [PMID: 21335468 DOI: 10.1152/ajpheart.00411.2010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
A decrease in peak early diastolic filling velocity in postmenopausal women implies a sex hormone-related diastolic dysfunction. The regulatory effect of female sex hormones on cardiac distensibility therefore was evaluated in ovariectomized rats by determining the sarcomere length-passive tension relationship of ventricular skinned fiber preparations. Diabetes also was induced in the rat to assess the protective significance of female sex hormones on diastolic function. While ovariectomy had no effect on myocardial stiffness, collagen content, or titin ratio, a significant increase in myocardial stiffness was observed in diabetic rat only when female sex hormones were intact. The increased stiffness in diabetic-sham rats was accompanied by an elevated collagen content resulting from increases in the levels of procollagen and Smad2. Surprisingly, the increased myocardial stiffness in diabetic-sham rats was accompanied by a shift toward a more compliant N2BA of cardiac titin isoforms. The pCa-active tension relationship was analyzed at fixed sarcomere lengths of 2.0 and 2.3 μm to determine the magnitude of changes in myofilament Ca(2+) sensitivity between the two sarcomere lengths. Interestingly, high expression of N2BA titin was associated with a suppressed magnitude of changes in myofilament Ca(2+) sensitivity only in the diabetic-ovariectomized condition. Estrogen supplementation in diabetic-ovariectomized rats partially increased myocardial stiffness but completely reversed the change in myofilament Ca(2+) sensitivity. These results indicate a restrictive adaptation of myocardium governed by female sex hormones to maintain myofilament activity in compensation to the pathophysiological induction of cardiac dilatation by the diabetic condition.
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Affiliation(s)
- Tepmanas Bupha-Intr
- Faculty of Science, Department of Physiology, Mahidol University, Bangkok, Thailand.
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25
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Bupha-Intr T, Laosiripisan J, Wattanapermpool J. Moderate intensity of regular exercise improves cardiac SR Ca2+ uptake activity in ovariectomized rats. J Appl Physiol (1985) 2009; 107:1105-12. [PMID: 19679745 DOI: 10.1152/japplphysiol.00407.2009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The impact of regular exercise in protecting cardiac deteriorating results of female sex hormone deprivation was evaluated by measuring changes in intracellular Ca2+ removal activity of sarcoplasmic reticulum (SR) in ovariectomized rats following 9-wk treadmill running exercise at moderate intensity. Despite induction of cardiac hypertrophy in exercised groups of both sham-operated and ovariectomized rats, exercise training had no effect on SR Ca2+ uptake and SR Ca(2+)-ATPase (SERCA) in hormone intact rat heart. However, exercise training normalized the suppressed maximum SR Ca2+ uptake and SERCA activity in ovariectomized rat heart. While exercise training normalized the leftward shift in pCa (-log[Ca2+])-SR Ca2+ uptake relation in ovariectomized rats, no effect was detected in exercised sham-operated rats. Similar phenomena were also observed on SERCA and on phospholamban (PLB) phosphorylation levels; exercise training in ovariectomized rats enhanced SERCA expression to reach the level as that in sham-operated rats, in which there were no differences in SERCA and phospho-PLB levels between sedentary and exercised groups. In addition, the reduction in phospho-Thr(17) PLB in myocardium of ovariectomized rats was abolished by exercise training. These results showed that regular exercise maintains the molecular activation of cardiac SR Ca2+ uptake under normal physiological conditions and is able to induce a protective impact on cardiac SR Ca2+ uptake in ovarian sex hormone-deprived status.
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Affiliation(s)
- Tepmanas Bupha-Intr
- Department of Physiology, Faculty of Science, Mahidol Univ., Rama 6 Road, Bangkok 10400, Thailand
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26
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Kilić A, Javadov S, Karmazyn M. Estrogen exerts concentration-dependent pro-and anti-hypertrophic effects on adult cultured ventricular myocytes. Role of NHE-1 in estrogen-induced hypertrophy. J Mol Cell Cardiol 2009; 46:360-9. [DOI: 10.1016/j.yjmcc.2008.11.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 11/25/2008] [Accepted: 11/26/2008] [Indexed: 10/21/2022]
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27
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Palmer BM, Wang Y, Teekakirikul P, Hinson JT, Fatkin D, Strouse S, Vanburen P, Seidman CE, Seidman JG, Maughan DW. Myofilament mechanical performance is enhanced by R403Q myosin in mouse myocardium independent of sex. Am J Physiol Heart Circ Physiol 2008; 294:H1939-47. [PMID: 18281382 DOI: 10.1152/ajpheart.00644.2007] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Male but not female mice carrying a single R403Q missense allele for cardiac alpha-myosin heavy chain (M-alphaMHC(R403Q/+) and F-alphaMHC(R403Q/+), respectively) develop significant hypertrophic cardiomyopathy (HCM) compared with male and female wild-type mice (M-alphaMHC(+/+) and F-alphaMHC(+/+), respectively) after approximately 30 wk of age. We tested the hypothesis that myofilament mechanical performance differs between M-alphaMHC(R403Q/+) and F-alphaMHC(R403Q/+) at younger ages (10-20 wk) and could account for sex differences in HCM development. The sensitivity of chemically skinned myocardial strips to Ca(2+) activation (pCa(50)) was significantly (P < 0.05) enhanced in male mice independent of genotype (M-alphaMHC(R403Q/+): 5.70 +/- 0.06, M-alphaMHC(+/+): 5.63 +/- 0.05, F-alphaMHC(R403Q/+): 5.57 +/- 0.03, F-alphaMHC(+/+): 5.54 +/- 0.04) by two-way ANOVA, whereas maximum developed tension was significantly enhanced in alpha-MHC(R403Q/+) independent of sex (M-alphaMHC(R403Q/+): 29.3 +/- 2.3, M-alphaMHC(+/+): 26.0 +/- 1.4, F-alphaMHC(R403Q/+): 30.2 +/- 2.1, F-alphaMHC(+/+): 26.2 +/- 1.2 mN/mm(2)). The frequency of maximum work generated by sinusoidal length perturbation was significantly higher in alphaMHC(R403Q/+) mice than in sex-matched controls (M-alphaMHC(R403Q/+): 2.26 +/- 0.47, M-alphaMHC(+/+): 1.29 +/- 0.18, F-alphaMHC(R403Q/+): 3.21 +/- 0.33, F-alphaMHC(+/+): 2.52 +/- 0.36 Hz). Unloaded shortening velocity was significantly enhanced in alphaMHC(R403Q/+) and in female mice (M-alphaMHC(R403Q/+): 2.26 +/- 0.47, M-alphaMHC(+/+): 1.29 +/- 0.18, F-alphaMHC(R403Q/+): 3.21 +/- 0.33, F-alphaMHC(+/+): 2.52 +/- 0.36 muscle lengths/s), and normalized mechanical power, calculated from the tension-velocity relationship, was significantly enhanced in alphaMHC(R403Q/+) independent of sex (M-alphaMHC(R403Q/+): 60 +/- 2 10(-3), M-alphaMHC(+/+): 37 +/- 3 10(-3), F-alphaMHC(R403Q/+): 57 +/- 3 10(-3), F-alphaMHC(+/+) 25 +/- 3 10(-3) muscle lengths/s x normalized tension). We did not find a statistically significant sex x mutation interaction for any measure of myofilament performance. Therefore, sarcomeric incorporation of the R403Q myosin similarly enhanced left ventricular myofilament mechanical performance in both male and female mice. The sex-dependent development of HCM due to the R403Q myosin may then be inhibited by female sex hormones, which may additionally underlie the observed sex differences for pCa(50) and unloaded shortening velocity.
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Affiliation(s)
- Bradley M Palmer
- Dept. of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA.
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Denton K, Baylis C. Physiological and molecular mechanisms governing sexual dimorphism of kidney, cardiac, and vascular function. Am J Physiol Regul Integr Comp Physiol 2007; 292:R697-9. [PMID: 17095645 DOI: 10.1152/ajpregu.00766.2006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Kate Denton
- Department of Physiology, Bldg. 13F, Monash University, Clayton, Victoria, Australia.
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