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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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Payne FM, Nie S, Diffee GM, Wilkins GT, Larsen DS, Harrison JC, Baldi JC, Sammut IA. The carbon monoxide prodrug oCOm-21 increases Ca 2+ sensitivity of the cardiac myofilament. Physiol Rep 2024; 12:e15974. [PMID: 38491822 PMCID: PMC10943376 DOI: 10.14814/phy2.15974] [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: 10/13/2023] [Revised: 02/27/2024] [Accepted: 03/01/2024] [Indexed: 03/18/2024] Open
Abstract
Patients undergoing cardiopulmonary bypass procedures require inotropic support to improve hemodynamic function and cardiac output. Current inotropes such as dobutamine, can promote arrhythmias, prompting a demand for improved inotropes with little effect on intracellular Ca2+ flux. Low-dose carbon monoxide (CO) induces inotropic effects in perfused hearts. Using the CO-releasing pro-drug, oCOm-21, we investigated if this inotropic effect results from an increase in myofilament Ca2+ sensitivity. Male Sprague Dawley rat left ventricular cardiomyocytes were permeabilized, and myofilament force was measured as a function of -log [Ca2+ ] (pCa) in the range of 9.0-4.5 under five conditions: vehicle, oCOm-21, the oCOm-21 control BP-21, and levosimendan, (9 cells/group). Ca2+ sensitivity was assessed by the Ca2+ concentration at which 50% of maximal force is produced (pCa50 ). oCOm-21, but not BP-21 significantly increased pCa50 compared to vehicle, respectively (pCa50 5.52 vs. 5.47 vs. 5.44; p < 0.05). No change in myofilament phosphorylation was seen after oCOm-21 treatment. Pretreatment of cardiomyocytes with the heme scavenger hemopexin, abolished the Ca2+ sensitizing effect of oCOm-21. These results support the hypothesis that oCOm-21-derived CO increases myofilament Ca2+ sensitivity through a heme-dependent mechanism but not by phosphorylation. Further analyses will confirm if this Ca2+ sensitizing effect occurs in an intact heart.
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Affiliation(s)
- Fergus M. Payne
- School of Biomedical Sciences, Department of Pharmacology and ToxicologyUniversity of OtagoDunedinOtagoNew Zealand
- Otago Medical School, Department of MedicineUniversity of OtagoDunedinOtagoNew Zealand
- HeartOtagoUniversity of OtagoDunedinNew Zealand
| | - Samantha Nie
- School of Biomedical Sciences, Department of Pharmacology and ToxicologyUniversity of OtagoDunedinOtagoNew Zealand
- HeartOtagoUniversity of OtagoDunedinNew Zealand
| | - Gary M. Diffee
- Department of KinesiologyUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - Gerard T. Wilkins
- Otago Medical School, Department of MedicineUniversity of OtagoDunedinOtagoNew Zealand
- HeartOtagoUniversity of OtagoDunedinNew Zealand
| | - David S. Larsen
- School of Science, Department of ChemistryUniversity of OtagoDunedinOtagoNew Zealand
| | - Joanne C. Harrison
- School of Biomedical Sciences, Department of Pharmacology and ToxicologyUniversity of OtagoDunedinOtagoNew Zealand
- HeartOtagoUniversity of OtagoDunedinNew Zealand
| | - James C. Baldi
- Otago Medical School, Department of MedicineUniversity of OtagoDunedinOtagoNew Zealand
- HeartOtagoUniversity of OtagoDunedinNew Zealand
| | - Ivan A. Sammut
- School of Biomedical Sciences, Department of Pharmacology and ToxicologyUniversity of OtagoDunedinOtagoNew Zealand
- HeartOtagoUniversity of OtagoDunedinNew Zealand
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3
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Hunter SK, S Angadi S, Bhargava A, Harper J, Hirschberg AL, D Levine B, L Moreau K, J Nokoff N, Stachenfeld NS, Bermon S. The Biological Basis of Sex Differences in Athletic Performance: Consensus Statement for the American College of Sports Medicine. Med Sci Sports Exerc 2023; 55:2328-2360. [PMID: 37772882 DOI: 10.1249/mss.0000000000003300] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
ABSTRACT Biological sex is a primary determinant of athletic performance because of fundamental sex differences in anatomy and physiology dictated by sex chromosomes and sex hormones. Adult men are typically stronger, more powerful, and faster than women of similar age and training status. Thus, for athletic events and sports relying on endurance, muscle strength, speed, and power, males typically outperform females by 10%-30% depending on the requirements of the event. These sex differences in performance emerge with the onset of puberty and coincide with the increase in endogenous sex steroid hormones, in particular testosterone in males, which increases 30-fold by adulthood, but remains low in females. The primary goal of this consensus statement is to provide the latest scientific knowledge and mechanisms for the sex differences in athletic performance. This review highlights the differences in anatomy and physiology between males and females that are primary determinants of the sex differences in athletic performance and in response to exercise training, and the role of sex steroid hormones (particularly testosterone and estradiol). We also identify historical and nonphysiological factors that influence the sex differences in performance. Finally, we identify gaps in the knowledge of sex differences in athletic performance and the underlying mechanisms, providing substantial opportunities for high-impact studies. A major step toward closing the knowledge gap is to include more and equitable numbers of women to that of men in mechanistic studies that determine any of the sex differences in response to an acute bout of exercise, exercise training, and athletic performance.
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Affiliation(s)
- Sandra K Hunter
- Exercise Science Program, Department of Physical Therapy, and Athletic and Human Performance Center, Marquette University, Milwaukee, WI
| | | | - Aditi Bhargava
- Department of Obstetrics and Gynecology, Center for Reproductive Sciences, University of California, San Francisco, CA
| | - Joanna Harper
- Loughborough University, Loughborough, UNITED KINGDOM
| | - Angelica Lindén Hirschberg
- Department of Women's and Children's Health, Karolinska Institutet, and Department of Gynecology and Reproductive Medicine, Karolinska University Hospital, Stockholm, SWEDEN
| | - Benjamin D Levine
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, and the Department of Internal Medicine, Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, TX
| | - Kerrie L Moreau
- Department of Medicine, Division of Geriatric Medicine, University of Colorado Anschutz Medical Campus, and Eastern Colorado Health Care System, Geriatric Research Education and Clinical Center, Aurora, CO
| | - Natalie J Nokoff
- Department of Pediatrics, Section of Endocrinology, University of Colorado Anschutz Medical Campus, Aurora, CO
| | - Nina S Stachenfeld
- The John B. Pierce Laboratory and Department of Obstetrics, Gynecology and Reproductive Sciences, Yale School of Medicine, New Haven, CT
| | - Stéphane Bermon
- Health and Science Department, World Athletics, Monaco and the LAMHESS, University Côte d'Azur, Nice, FRANCE
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Sciatti E, Coccia MG, Magnano R, Aakash G, Limonta R, Diep B, Balestrieri G, D'Isa S, Abramov D, Parwani P, D'Elia E. Heart Failure Preserved Ejection Fraction in Women: Insights Learned from Imaging. Heart Fail Clin 2023; 19:461-473. [PMID: 37714587 DOI: 10.1016/j.hfc.2023.06.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/17/2023]
Abstract
While the prevalence of heart failure, in general, is similar in men and women, women experience a higher rate of HFpEF compared to HFrEF. Cardiovascular risk factors, parity, estrogen levels, cardiac physiology, and altered response to the immune system may be at the root of this difference. Studies have found that in response to increasing age and hypertension, women experience more concentric left ventricle remodeling, more ventricular and arterial stiffness, and less ventricular dilation compared to men, which predisposes women to developing more diastolic dysfunction. A multi-modality imaging approach is recommended to identify patients with HFpEF. Particularly, appreciation of sex-based differences as described in this review is important in optimizing the evaluation and care of women with HFpEF.
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Affiliation(s)
- Edoardo Sciatti
- Cardiology Unit, Hospital Papa Giovanni XXIII, Bergamo, Italy
| | | | | | - Gupta Aakash
- Division of Cardiology, Department of Medicine, Loma Linda University Health, Loma Linda, CA, USA
| | - Raul Limonta
- School of Medicine and Surgery, Milano Bicocca University, Milano, Italy
| | - Brian Diep
- Division of Cardiology, Department of Medicine, Loma Linda University Health, Loma Linda, CA, USA
| | | | - Salvatore D'Isa
- Cardiology Unit, Hospital Papa Giovanni XXIII, Bergamo, Italy
| | - Dmitry Abramov
- Division of Cardiology, Department of Medicine, Loma Linda University Health, Loma Linda, CA, USA
| | - Purvi Parwani
- Division of Cardiology, Department of Medicine, Loma Linda University Health, Loma Linda, CA, USA
| | - Emilia D'Elia
- Cardiology Unit, Hospital Papa Giovanni XXIII, Bergamo, Italy.
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5
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Rabender CS, Mezzaroma E, Yakovlev VA, Mauro AG, Bonaventura A, Abbate A, Mikkelsen RB. Mitigation of Radiation-Induced Lung and Heart Injuries in Mice by Oral Sepiapterin after Irradiation. Radiat Res 2021; 195:463-473. [PMID: 33822229 DOI: 10.1667/rade-20-00249.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 02/21/2021] [Indexed: 01/12/2023]
Abstract
After radiation exposure, endothelium-dependent vasorelaxation is impaired due to impaired nitric oxide production. Endothelial dysfunction is characterized by uncoupled endothelial nitric oxide synthase activity, oxidation of the reduced cofactor tetrahydrobiopterin to dihydrobiopterin as one well recognized mechanism. Oral treatment with sepiapterin, a tetrahydrobiopterin precursor, decreased infiltrating inflammatory cells and cytokine levels in mice with colitis. We therefore tested whether a synthetic sepiapterin, PTC923, might mitigate radiation-induced cardiac and pulmonary injuries. C57L/J wild-type 6-8-week-old mice of both sexes received 5 Gy total-body irradiation (TBI), followed by a top-up dose of 6.5 Gy to the thorax (total thoracic dose of 11.5 Gy). Starting from 24 h postirradiation, mice were treated once daily with 1 mg/kg PTC923 for six days by oral gavage. Assessment of lung injury by breathing rate was measured every other week and echocardiography to assess heart function was performed at different time points (8, 30, 60, 90 and 180 days). Plasma proteins (fibrinogen, neutrophil elastase, C-reactive protein, and IL-6) were assessed as well. TBI induced a reduction in cardiac contractile reserve and an impairment in diastolic function restored by daily oral PTC923. Postirradiation lung injury was significantly delayed by PTC923. TBI mice treated with PTC923 experienced a longer survival compared to nonirradiated mice (71% vs. 40% of mice alive after 180 days). PTC923-treated mice showed a reduction in inflammatory mediators, especially IL-6 and IL-1b. In conclusion, these findings support the proposal that PTC923 is a potential mitigator of cardiac and lung injury caused by TBI.
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Affiliation(s)
- Christopher S Rabender
- Department of Radiation Oncology, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Eleonora Mezzaroma
- Department of Pharmacotherapy and Outcomes Science, School of Pharmacy, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Vasily A Yakovlev
- Department of Radiation Oncology, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Adolfo G Mauro
- Internal Medicine, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Aldo Bonaventura
- Internal Medicine, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Antonio Abbate
- Internal Medicine, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Ross B Mikkelsen
- Department of Radiation Oncology, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
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6
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Sotomi Y, Hikoso S, Nakatani D, Mizuno H, Okada K, Dohi T, Kitamura T, Sunaga A, Kida H, Oeun B, Sato T, Komukai S, Tamaki S, Yano M, Hayashi T, Nakagawa A, Nakagawa Y, Yasumura Y, Yamada T, Sakata Y. Sex Differences in Heart Failure With Preserved Ejection Fraction. J Am Heart Assoc 2021; 10:e018574. [PMID: 33619973 PMCID: PMC8174270 DOI: 10.1161/jaha.120.018574] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background The female preponderance in heart failure with preserved ejection fraction (HFpEF) is a distinguishing feature of this disorder, but the association of sex with degree of diastolic dysfunction and clinical outcomes among individuals with HFpEF remains unclear. Methods and Results We conducted a prospective, multicenter, observational study of patients with HFpEF (PURSUIT‐HFpEF [Prospective Multicenter Observational Study of Patients with Heart Failure with Preserved Ejection Fraction]: UMIN000021831). Between 2016 and 2019, 871 patients were enrolled from 26 hospitals (follow‐up: 399±349 days). We investigated sex‐related differences in diastolic dysfunction and postdischarge clinical outcomes in patients with HFpEF. The echocardiographic end point was diastolic dysfunction according to American Society of Echocardiography/European Association of Cardiovascular Imaging criteria. The clinical end point was a composite of all‐cause death and heart failure readmission. Women accounted for 55.2% (481 patients) of the overall cohort. Compared with men, women were older and had lower prevalence rates of hypertension, coronary artery disease, and chronic kidney disease. Women had diastolic dysfunction more frequently than men (52.8% versus 32.0%, P<0.001). The incidence of the clinical end point did not differ between women and men (women 36.1/100 person‐years versus men 30.5/100 person‐years, P=0.336). Female sex was independently associated with the echocardiographic end point (adjusted odds ratio, 2.839; 95% CI, 1.884–4.278; P<0.001) and the clinical end point (adjusted hazard ratio, 1.538; 95% CI, 1.143–2.070; P=0.004). Conclusions Female sex was independently associated with the presence of diastolic dysfunction and worse clinical outcomes in a cohort of elderly patients with HFpEF. Our results suggest that a sex‐specific approach is key to investigating the pathophysiology of HFpEF. Registration URL: https://upload.umin.ac.jp; Unique identifier: UMIN000021831.
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Affiliation(s)
- Yohei Sotomi
- Department of Cardiovascular Medicine Osaka University Graduate School of Medicine Osaka Japan
| | - Shungo Hikoso
- Department of Cardiovascular Medicine Osaka University Graduate School of Medicine Osaka Japan
| | - Daisaku Nakatani
- Department of Cardiovascular Medicine Osaka University Graduate School of Medicine Osaka Japan
| | - Hiroya Mizuno
- Department of Cardiovascular Medicine Osaka University Graduate School of Medicine Osaka Japan
| | - Katsuki Okada
- Department of Cardiovascular Medicine Osaka University Graduate School of Medicine Osaka Japan
| | - Tomoharu Dohi
- Department of Cardiovascular Medicine Osaka University Graduate School of Medicine Osaka Japan
| | - Tetsuhisa Kitamura
- Department of Social and Environmental Medicine Osaka University Graduate School of Medicine Osaka Japan
| | - Akihiro Sunaga
- Department of Cardiovascular Medicine Osaka University Graduate School of Medicine Osaka Japan
| | - Hirota Kida
- Department of Cardiovascular Medicine Osaka University Graduate School of Medicine Osaka Japan
| | - Bolrathanak Oeun
- Department of Cardiovascular Medicine Osaka University Graduate School of Medicine Osaka Japan
| | - Taiki Sato
- Department of Cardiovascular Medicine Osaka University Graduate School of Medicine Osaka Japan
| | - Sho Komukai
- Division of Biomedical Statistics Department of Integrated Medicine Graduate School of Medicine Osaka University Osaka Japan
| | - Shunsuke Tamaki
- Division of Cardiology Osaka General Medical Center Osaka Japan
| | | | | | - Akito Nakagawa
- Division of Cardiology Amagasaki Chuo Hospital Hyogo Japan.,Department of Medical Informatics Osaka University Graduate School of Medicine Suita Japan
| | | | | | - Takahisa Yamada
- Division of Cardiology Osaka General Medical Center Osaka Japan
| | - Yasushi Sakata
- Department of Cardiovascular Medicine Osaka University Graduate School of Medicine Osaka Japan
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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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Lo Muzio FP, Rozzi G, Rossi S, Gerbolés AG, Fassina L, Pelà G, Luciani GB, Miragoli M. In-situ optical assessment of rat epicardial kinematic parameters reveals frequency-dependent mechanic heterogeneity related to gender. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 154:94-101. [PMID: 31126627 DOI: 10.1016/j.pbiomolbio.2019.05.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 05/06/2019] [Accepted: 05/08/2019] [Indexed: 12/29/2022]
Abstract
BACKGROUND Gender-related cardiac mechanics following the electrical activity has been investigated from basic to clinical research, but results are still controversial. The aim of this work is to study the gender related cardiac mechanics and to focus on its heart rate dependency. METHODS We employed 12 Sprague Dawley rats (5 males and 7 females) of the same age and, through a novel high resolution artificial vision contactless approach, we evaluated in-situ cardiac kinematic. The hearts were paced on the right atria appendage via cathodal stimuli at rising frequency. RESULTS Kinematic data obtained at rising pacing rates are different between male and female rat hearts: male tended to maintain the same level of cardiac force, energy and contractility, while female responded with an increment of such parameters at increasing heart rate. Female hearts preserved their pattern of contraction and epicardial torsion (vorticity) at rising pacing rates compared to male. Furthermore, we observed a difference in the mechanical restitution: systolic time vs. diastolic time, as an index of cardiac performance, reached higher value in male compared to female hearts. CONCLUSION Our innovative technology was capable to evaluate in-situ rat epicardial kinematic at high stimulation frequency, revealing that male preserved kinematic parameters but varying the pattern of contraction/relaxation. On the contrary, female preserved the pattern of contraction/relaxation increasing kinematic parameters.
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Affiliation(s)
- Francesco Paolo Lo Muzio
- Department of Surgery, Dentistry, Paediatrics and Gynaecology, University of Verona Via S. Francesco 22, 37129, Verona, Italy; Department of Medicine and Surgery, University di Parma, via Gramsci 14, 43126, Parma, Italy
| | - Giacomo Rozzi
- Department of Surgery, Dentistry, Paediatrics and Gynaecology, University of Verona Via S. Francesco 22, 37129, Verona, Italy; Department of Medicine and Surgery, University di Parma, via Gramsci 14, 43126, Parma, Italy
| | - Stefano Rossi
- Department of Medicine and Surgery, University di Parma, via Gramsci 14, 43126, Parma, Italy
| | | | - Lorenzo Fassina
- Department of Industrial Engineering and Informatics, University of Pavia, Via Ferrata 1, 27100, Pavia, Italy
| | - Giovanna Pelà
- Department of Medicine and Surgery, University di Parma, via Gramsci 14, 43126, Parma, Italy
| | - Giovanni Battista Luciani
- Department of Surgery, Dentistry, Paediatrics and Gynaecology, University of Verona Via S. Francesco 22, 37129, Verona, Italy
| | - Michele Miragoli
- Department of Medicine and Surgery, University di Parma, via Gramsci 14, 43126, Parma, Italy; Humanitas Clinical and Research Center, Via Manzoni 56, 20089, Rozzano, Italy.
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9
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Cardiovascular sexual dimorphism in a diet-induced type 2 diabetes rodent model, the Nile rat (Arvicanthis niloticus). PLoS One 2018; 13:e0208987. [PMID: 30589871 PMCID: PMC6307866 DOI: 10.1371/journal.pone.0208987] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/28/2018] [Indexed: 12/12/2022] Open
Abstract
Background The Nile rat (Arvicanthis niloticus) is an emerging laboratory model of type 2 diabetes. When fed standard rodent chow, the majority of males progress from hyperinsulinemia by 2 months to hyperglycemia by 6 months, while most females remain at the hyperinsulinemia-only stage (prediabetic) from 2 months onward. Since diabetic cardiomyopathy is the major cause of type-2 diabetes mellitus (T2DM)-related mortality, we examined whether sexual dimorphism might entail cardiac functional changes. Our ultimate goal was to isolate the effect of diet as a modifiable lifestyle factor. Materials and methods Nile rats were fed either standard rodent chow (Chow group) or a high-fiber diet previously established to prevent type 2 diabetes (Fiber group). Cardiac function was determined with echocardiography at 12 months of age. To isolate the effect of diet alone, only the small subset of animals resistant to both hyperinsulinemia and hyperglycemia were included in this study. Results In males, Chow (compared to Fiber) was associated with elevated heart rate and mitral E/A velocity ratio, and with lower e’-wave velocity, isovolumetric relaxation time, and ejection time. Of note, these clinically atypical types of diastolic dysfunction occurred independently of body weight. In contrast, females did not exhibit changes in cardiovascular function between diets. Conclusions The higher prevalence of T2DM in males correlates with their susceptibility to develop subtle diastolic cardiac dysfunction when fed a Western style diet (throughout most of their lifespan) despite no systemic evidence of metabolic syndrome, let alone T2DM.
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10
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Abstract
Heart failure (HF) represents a global pandemic health problem with a high impact on health-care costs, affecting about 26 million adults worldwide. The overall HF prevalence and incidence are ~2% and ~0.2% per year, respectively, in Western countries, with half of the HF population with reduced ejection fraction (HFpEF) and half with preserved (HFpEF) or mid-range ejection fraction (HFmrEF). Sex differences may exist in HF. More males have HFrEF or HFmrEF and an ischemic etiology, whereas more females have HFpEF and hypertension, diastolic dysfunction, and valvular pathologies as HF etiologies. Females are generally older, have a higher EF, higher frequency of HF-related symptoms, and lower NYHA functional status. Generally, it is observed that female HF patients tend to have more comorbidities such as atrial fibrillation, diabetes, hypertension, anemia, iron deficiency, renal disease, arthritis, frailty, depression, and thyroid abnormalities. However, overall, females have better prognosis in terms of mortality and hospitalization risk compared with men, regardless of EF. Potential sex differences in HF characteristics may be underestimated because of the underrepresentation of females in cardiovascular research and, in particular, the sex imbalance in clinical trial enrollment may avoid to identify sex-specific differences in treatments' benefit.
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11
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Hall PS, Nah G, Howard BV, Lewis CE, Allison MA, Sarto GE, Waring ME, Jacobson LT, Manson JE, Klein L, Parikh NI. Reproductive Factors and Incidence of Heart Failure Hospitalization in the Women's Health Initiative. J Am Coll Cardiol 2017; 69:2517-2526. [PMID: 28521890 PMCID: PMC5602586 DOI: 10.1016/j.jacc.2017.03.557] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 03/10/2017] [Accepted: 03/12/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Reproductive factors reflective of endogenous sex hormone exposure might have an effect on cardiac remodeling and the development of heart failure (HF). OBJECTIVES This study examined the association between key reproductive factors and the incidence of HF. METHODS Women from a cohort of the Women's Health Initiative were systematically evaluated for the incidence of HF hospitalization from study enrollment through 2014. Reproductive factors (number of live births, age at first pregnancy, and total reproductive duration [time from menarche to menopause]) were self-reported at study baseline in 1993 to 1998. We employed Cox proportional hazards regression analysis in age- and multivariable-adjusted models. RESULTS Among 28,516 women, with an average age of 62.7 ± 7.1 years at baseline, 1,494 (5.2%) had an adjudicated incident HF hospitalization during an average follow-up of 13.1 years. After adjusting for covariates, total reproductive duration in years was inversely associated with incident HF: hazard ratios (HRs) of 0.99 per year (95% confidence interval [CI]: 0.98 to 0.99 per year) and 0.95 per 5 years (95% CI: 0.91 to 0.99 per 5 years). Conversely, early age at first pregnancy and nulliparity were significantly associated with incident HF in age-adjusted models, but not after multivariable adjustment. Notably, nulliparity was associated with incident HF with preserved ejection fraction in the fully adjusted model (HR: 2.75; 95% CI: 1.16 to 6.52). CONCLUSIONS In post-menopausal women, shorter total reproductive duration was associated with higher risk of incident HF, and nulliparity was associated with higher risk for incident HF with preserved ejection fraction. Whether exposure to endogenous sex hormones underlies this relationship should be investigated in future studies.
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Affiliation(s)
- Philip S Hall
- Division of Cardiology, University of California, San Francisco, San Francisco, California
| | - Gregory Nah
- Division of Cardiology, University of California, San Francisco, San Francisco, California
| | - Barbara V Howard
- MedStar Health Research Institute and Georgetown/Howard Universities Center for Clinical and Translational Research, Hyattsville, Maryland
| | - Cora E Lewis
- Division of Preventive Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Matthew A Allison
- Division of Preventive Medicine, University of California, San Diego, La Jolla, California
| | - Gloria E Sarto
- Department of Obstetrics and Gynecology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Molly E Waring
- Department of Quantitative Health Sciences, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Lisette T Jacobson
- Department of Preventive Medicine and Public Health, University of Kansas School of Medicine-Wichita, Wichita, Kansas
| | - JoAnn E Manson
- Division of Preventive Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Liviu Klein
- Division of Cardiology, University of California, San Francisco, San Francisco, California
| | - Nisha I Parikh
- Division of Cardiology, University of California, San Francisco, San Francisco, California.
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12
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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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13
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Praktiknjo SD, Picard S, Deschepper CF. Comparisons of chromosome Y-substituted mouse strains reveal that the male-specific chromosome modulates the effects of androgens on cardiac functions. Biol Sex Differ 2016; 7:61. [PMID: 27980711 PMCID: PMC5143463 DOI: 10.1186/s13293-016-0116-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 11/09/2016] [Indexed: 01/06/2023] Open
Abstract
Background The C57BL/6J.YA/J mouse strain is a chromosome-substituted line where the original male-specific portion of chromosome Y (MSY) from C57BL/6J mice was substituted for that from A/J mice. In hearts from male C57BL/6J.YA/J and C57BL/6J mice, orchidectomy (ORX) affected in a strictly strain-specific fashion the expression a subset of genes showing enrichment for functional categories, including that of circadian rhythms and cardiac contractility. We further tested whether: (1) there were strain-specific differences in cardiac circadian rhythms; (2) strain-dependent differences in the effects of ORX on contractility genes translated into differences in cardiac functions; and (3) differential contractility responses occurred preferentially at times when circadian rhythms also showed strain-specific differences. Methods In hearts from the two above strains, we (1) profiled the expression levels of 15 circadian genes at 4-h intervals across a 24 h period; (2) tested the effects of either ORX or androgen replacement on expression of cardiac contractility genes, and that of ORX on myocardial functional reserve; and (3) verified whether the effects of MSY variants on cardiac contractility-related responses showed synchronicity with differences in circadian rhythms. Results Among the 15 tested circadian genes, a subset of them were affected by strain (and thus the genetic origin of MSY), which interacted with the amplitude of their peak of maximal expression at 2:00 PM. At that same time-point, ORX decreased (and androgen supplementation increased) the expression of three contractility-related genes, and decreased myocardial relaxation reserve in C57BL/6J.YA/J, but not in C57BL/6J mice. These effects were not detected at 10:00 AM, i.e., at another time-point when circadian genes showed no strain-specific differences. Conclusions The results indicate that in mice, androgens have activational effects on cardiac circadian rhythms, contractile gene expression, and myocardial functional reserve. All effects occurred preferentially at the same time of the day, but varied as a function of the genetic origin of MSY. Androgens may therefore be necessary but not sufficient to impart male-specific characteristics to some particular cardiac functions, with genetic material from MSY being one other necessary factor to fully define their range of actions. Electronic supplementary material The online version of this article (doi:10.1186/s13293-016-0116-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Samantha D Praktiknjo
- Institut de recherches cliniques de Montréal (IRCM) and Dept of Medicine, Cardiovascular Biology Research Unit, Université de Montréal, 100 Pine Ave West, Montreal, QC H2W 1R7 Canada ; Present address: Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine (MDC) in the Helmholtz Association, Robert-Rössle-Str. 10, D-13125 Berlin, Germany
| | - Sylvie Picard
- Institut de recherches cliniques de Montréal (IRCM) and Dept of Medicine, Cardiovascular Biology Research Unit, Université de Montréal, 100 Pine Ave West, Montreal, QC H2W 1R7 Canada
| | - Christian F Deschepper
- Institut de recherches cliniques de Montréal (IRCM) and Dept of Medicine, Cardiovascular Biology Research Unit, Université de Montréal, 100 Pine Ave West, Montreal, QC H2W 1R7 Canada
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14
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Nuclear translocation of the cardiac L-type calcium channel C-terminus is regulated by sex and 17β-estradiol. J Mol Cell Cardiol 2016; 97:226-34. [DOI: 10.1016/j.yjmcc.2016.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 05/03/2016] [Accepted: 06/02/2016] [Indexed: 12/17/2022]
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15
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Fischer TH, Herting J, Eiringhaus J, Pabel S, Hartmann NH, Ellenberger D, Friedrich M, Renner A, Gummert J, Maier LS, Zabel M, Hasenfuss G, Sossalla S. Sex-dependent alterations of Ca2+ cycling in human cardiac hypertrophy and heart failure. Europace 2015; 18:1440-8. [PMID: 26493982 DOI: 10.1093/europace/euv313] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 08/19/2015] [Indexed: 11/12/2022] Open
Abstract
AIMS Clinical studies have shown differences in the propensity for malignant ventricular arrhythmias between women and men suffering from cardiomyopathies and heart failure (HF). This is clinically relevant as it impacts therapies like prophylactic implantable cardioverter-defibrillator implantation but the pathomechanisms are unknown. As an increased sarcoplasmic reticulum (SR) Ca(2+) leak is arrhythmogenic, it could represent a cellular basis for this paradox. METHODS/RESULTS We evaluated the SR Ca(2+) leak with respect to sex differences in (i) afterload-induced cardiac hypertrophy (Hy) with preserved left ventricular (LV) function and (ii) end-stage HF. Cardiac function did not differ between sexes in both cardiac pathologies. Human cardiomyocytes isolated from female patients with Hy showed a significantly lower Ca(2+) spark frequency (CaSpF, confocal microscopy, Fluo3-AM) compared with men (P < 0.05). As Ca(2+) spark width and duration were similar in women and men, this difference in CaSpF did not yet translate into a significant difference of the calculated SR Ca(2+) leak between both sexes at this stage of disease (P = 0.14). Epifluorescence measurements (Fura2-AM) revealed comparable Ca(2+) cycling properties (diastolic Ca(2+) levels, amplitude of systolic Ca(2+) transients, SR Ca(2+) load) in patients of both sexes suffering from Hy. Additionally, the increased diastolic CaSpF in male patients with Hy did not yet translate into an elevated ratio of cells showing arrhythmic events (Ca(2+) waves, spontaneous Ca(2+) transients) (P = 0.77). In the transition to HF, both sexes showed an increase of the CaSpF (P < 0.05) and the sex dependence was even more pronounced. Female patients had a 69 ± 10% lower SR Ca(2+) leak (P < 0.05), which now even translated into a lower ratio of arrhythmic cells in female HF patients compared with men (P < 0.001). CONCLUSION These data show that the SR Ca(2+) leak is lower in women than in men with comparable cardiac impairment. Since the SR Ca(2+) leak triggers delayed afterdepolarizations, our findings may explain why women are less prone to ventricular arrhythmias and confirm the rationale of therapeutic measures reducing the SR Ca(2+) leak.
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Affiliation(s)
- Thomas H Fischer
- Klinik für Kardiologie und Pneumologie/Herzzentrum, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Jonas Herting
- Klinik für Kardiologie und Pneumologie/Herzzentrum, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Jörg Eiringhaus
- Klinik für Kardiologie und Pneumologie/Herzzentrum, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Steffen Pabel
- Klinik für Kardiologie und Pneumologie/Herzzentrum, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Nico H Hartmann
- Klinik für Kardiologie und Pneumologie/Herzzentrum, Georg-August-Universität Göttingen, Göttingen, Germany
| | - David Ellenberger
- Institut für Medizinische Statistik, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Martin Friedrich
- Abt. Thorax-, Herz- und Gefäßchirurgie, Herzzentrum, Georg-August-Universität Göttingen, Göttingen, Germany
| | - André Renner
- Abt. Thorax-, Herz-, Gefäßchirurgie, Herz- und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany
| | - Jan Gummert
- Abt. Thorax-, Herz-, Gefäßchirurgie, Herz- und Diabeteszentrum Nordrheinwestfalen, Bad Oeynhausen, Germany
| | - Lars S Maier
- Klinik und Poliklinik für Innere Medizin II, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Markus Zabel
- Klinik für Kardiologie und Pneumologie/Herzzentrum, Georg-August-Universität Göttingen, Göttingen, Germany Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), Standort Göttingen, Germany
| | - Gerd Hasenfuss
- Klinik für Kardiologie und Pneumologie/Herzzentrum, Georg-August-Universität Göttingen, Göttingen, Germany Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), Standort Göttingen, Germany
| | - Samuel Sossalla
- Klinik für Kardiologie und Pneumologie/Herzzentrum, Georg-August-Universität Göttingen, Göttingen, Germany Deutsches Zentrum für Herz-Kreislauf-Forschung (DZHK), Standort Göttingen, Germany
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16
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Rafikova O, Rafikov R, Meadows ML, Kangath A, Jonigk D, Black SM. The sexual dimorphism associated with pulmonary hypertension corresponds to a fibrotic phenotype. Pulm Circ 2015; 5:184-97. [PMID: 25992281 DOI: 10.1086/679724] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 08/18/2014] [Indexed: 01/23/2023] Open
Abstract
Although female predominance in the development of all types of pulmonary hypertension (PH) is well established, many clinical studies have confirmed that females have better prognosis and higher survival rate than males. There is no clear explanation of why sex influences the pathogenesis and progression of PH. Using a rat angioproliferative model of PH, which closely resembles the primary pathological changes observed in humans, we evaluated the role of sex in the development and progression of PH. Female rats had a more pronounced increase in medial thickness in the small pulmonary arteries. However, the infiltration of small pulmonary arteries by inflammatory cells was found only in male rats, and this corresponded to increased myeloperoxidase activity and abundant adventitial and medial fibrosis that were not present in female rats. Although the level of right ventricle (RV) peak systolic pressure was similar in both groups, the survival rate in male rats was significantly lower. Moreover, male rats presented with a more pronounced increase in RV thickness that correlated with diffuse RV fibrosis and significantly impaired right cardiac function. The reduction in fibrosis in female rats correlated with increased expression of caveolin-1 and reduced endothelial nitric oxide synthase-derived superoxide. We conclude that, in the pathogenesis of PH, female sex is associated with greater remodeling of the pulmonary arteries but greater survival. Conversely, in males, the development of pulmonary and cardiac fibrosis leads to early and severe RV failure, and this may be an important reason for the lower survival rate among males.
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Affiliation(s)
- Olga Rafikova
- Pulmonary Vascular Disease Program, Vascular Biology Center, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, USA ; These authors contributed equally to this study
| | - Ruslan Rafikov
- Pulmonary Vascular Disease Program, Vascular Biology Center, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, USA ; These authors contributed equally to this study
| | - Mary Louise Meadows
- Pulmonary Vascular Disease Program, Vascular Biology Center, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, USA
| | - Archana Kangath
- Pulmonary Vascular Disease Program, Vascular Biology Center, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, USA
| | - Danny Jonigk
- Institute of Pathology, Hannover Medical School, Hanover, Germany
| | - Stephen M Black
- Pulmonary Vascular Disease Program, Vascular Biology Center, Medical College of Georgia, Georgia Regents University, Augusta, Georgia, USA
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17
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Ostadal B, Ostadal P. Sex-based differences in cardiac ischaemic injury and protection: therapeutic implications. Br J Pharmacol 2014; 171:541-54. [PMID: 23750471 DOI: 10.1111/bph.12270] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Revised: 05/21/2013] [Accepted: 05/30/2013] [Indexed: 12/22/2022] Open
Abstract
Ischaemic heart disease (IHD) is the most frequent cause of mortality among men and women. Many epidemiological studies have demonstrated that premenopausal women have a reduced risk for IHD compared with their male counterparts. The incidence of IHD in women increases after menopause, suggesting that IHD is related to declining oestrogen levels. Experimental observations have confirmed the results of epidemiological studies investigating sex-specific differences in cardiac tolerance to ischaemia. Female sex appears also to favourably influence cardiac remodelling after ischaemia/reperfusion injury. Furthermore, sex-related differences in ischaemic tolerance of the adult myocardium can be influenced by interventions during the early phases of ontogenetic development. Detailed mechanisms of these sex-related differences remain unknown; however, they involve the genomic and non-genomic effects of sex steroid hormones, particularly the oestrogens, which have been the most extensively studied. Although the protective effects of oestrogen have many potential therapeutic implications, clinical trials have shown that oestrogen replacement in postmenopausal women may actually increase the incidence of IHD. The results of these trials have illustrated the complexity underlying the mechanisms involved in sex-related differences in cardiac tolerance to ischaemia. Sex-related differences in cardiac sensitivity to ischaemia/reperfusion injury may also influence therapeutic strategies in women with acute coronary syndrome. Women undergo coronary intervention less frequently and a lower proportion of women receive evidence-based therapy compared with men. Although our understanding of this important topic has increased in recent years, there is an urgent need for intensive experimental and clinical research to develop female-specific therapeutic strategies. Only then we will be able to offer patients better evidence-based treatment, a better quality of life and lower mortality.
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Affiliation(s)
- B Ostadal
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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18
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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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19
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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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20
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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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21
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Wainstein RV, Sasson Z, Mak S. Frequency-dependent left ventricular performance in women and men. Am J Physiol Heart Circ Physiol 2012; 302:H2363-71. [DOI: 10.1152/ajpheart.01125.2011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We aimed to determine whether sex differences in humans extend to the dynamic response of the left ventricular (LV) chamber to changes in heart rate (HR). Several observations suggest sex influences LV structure and function in health; moreover, this physiology is also affected in a sex-specific manner by aging. Eight postmenopausal women and eight similarly aged men underwent a cardiac catheterization-based study for force-interval relationships of the LV. HR was controlled by right atrial (RA) pacing, and LV +dP/d tmax and volume were assessed by micromanometer-tipped catheter and Doppler echocardiography, respectively. Analysis of approximated LV pressure-volume relationships was performed using a time-varying model of elastance. External stroke work was also calculated. The relationship between HR and LV +dP/d tmax was expressed as LV +dP/d tmax = b + mHR. The slope ( m) of the relationship was steeper in women compared with men (11.8 ± 4.0 vs. 6.1 ± 4.1 mmHg·s−1·beats−1·min−1, P = 0.01). The greater increase in contractility in women was reproducibly observed after normalizing LV +dP/d tmax to LV end-diastolic volume (LVVed) or by measuring end-systolic elastance. LVVed and stroke volume decreased more in women. Thus, despite greater increases in contractility, HR was associated with a lesser rise in cardiac output and a steeper fall in external stroke work in women. Compared with men, women exhibit greater inotropic responses to incremental RA pacing, which occurs at the same time as a steeper decline in external stroke work. In older adults, we observed sexual dimorphism in determinants of LV mechanical performance.
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Affiliation(s)
| | - Zion Sasson
- The Harold & Esther Mecklinger Family and Posluns Family Cardiac Catheterization Research Laboratory, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada; and
| | - Susanna Mak
- The Harold & Esther Mecklinger Family and Posluns Family Cardiac Catheterization Research Laboratory, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada; and
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Abstract
Estrogen has pleiotropic effects on the cardiovascular system. The mechanisms by which estrogen confers these pleiotropic effects are undergoing active investigation. Until a decade ago, all estrogen signaling was thought to occur by estrogen binding to nuclear estrogen receptors (estrogen receptor-α and estrogen receptor-β), which bind to DNA and function as ligand-activated transcription factors. Estrogen binding to the receptor alters gene expression, thereby altering cell function. Estrogen also binds to nuclear estrogen receptors that are tethered to the plasma membrane, resulting in acute activation of signaling kinases such as PI3K. An orphan G-protein-coupled receptor, G-protein-coupled receptor 30, can also bind estrogen and activate acute signaling pathways. Thus, estrogen can alter cell function by binding to different estrogen receptors. This article reviews the different estrogen receptors and their signaling mechanisms, discusses mechanisms that regulate estrogen receptor levels and locations, and considers the cardiovascular effects of estrogen signaling.
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Affiliation(s)
- Elizabeth Murphy
- Cardiac Physiology Section, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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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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25
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Farrell SR, Ross JL, Howlett SE. Sex differences in mechanisms of cardiac excitation-contraction coupling in rat ventricular myocytes. Am J Physiol Heart Circ Physiol 2010; 299:H36-45. [DOI: 10.1152/ajpheart.00299.2010] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Components of excitation-contraction (E-C) coupling were compared in ventricular myocytes isolated from 3-mo-old male and female rats. Ca2+ concentrations (fura-2) and cell shortening (edge detector) were measured simultaneously (37°C). Membrane potential and ionic currents were measured with microelectrodes. Action potentials were similar in male and female myocytes, but contractions were smaller and slower in females. In voltage-clamped cells, peak contractions were smaller in females than in males (5.1 ± 0.7% vs. 7.7 ± 0.8% diastolic length, P < 0.05). Similarly, Ca2+ transients were smaller in females than in males and the rate of rise of the Ca2+ transient was slower in females. Despite smaller contractions and Ca2+ transients in females, Ca2+ current density was similar in both groups. Sarcoplasmic reticulum Ca2+ content, assessed with caffeine, did not differ between the sexes. However, E-C coupling gain (rate of Ca2+ release/Ca2+ current) was smaller in females than in males (157.0 ± 15.6 vs. 338.4 ± 54.3 (nM/s)/(pA/pF), P < 0.05). To determine whether the reduced gain in female cells was due to changes in unitary Ca2+ release, spontaneous Ca2+ sparks were evaluated (fluo-4, 37°C). Spark frequencies and widths were similar in both groups, but spark amplitudes were smaller in females than in males (0.56 ± 0.01 vs. 0.64 ± 0.01 ΔF/F0, P < 0.05). Spark durations also were shorter in females than in males (full duration at half-maximum = 14.86 ± 0.17 vs. 16.25 ± 0.27 ms, P < 0.05). These observations suggest that decreases in the size and duration of Ca2+ sparks contributes to the decrease in E-C coupling gain in female myocytes. Thus, differences in cardiac contractile function arise, in part, from differences in unitary Ca2+ release between the sexes.
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Affiliation(s)
| | | | - Susan E. Howlett
- Departments of 1Pharmacology and
- Medicine (Geriatric Medicine), Dalhousie University, Halifax, Nova Scotia, Canada
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26
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Marsh JD. Turning cardiac excitation into cell contraction: the importance of sex differences. Am J Physiol Heart Circ Physiol 2010; 299:H16-7. [PMID: 20495144 DOI: 10.1152/ajpheart.00444.2010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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27
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Bhupathy P, Haines CD, Leinwand LA. Influence of sex hormones and phytoestrogens on heart disease in men and women. ACTA ACUST UNITED AC 2010; 6:77-95. [PMID: 20088732 DOI: 10.2217/whe.09.80] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cardiovascular disease (CVD) is the number one cause of morbidity and mortality in men and women worldwide. According to the WHO, by 2015, almost 20 million people will die from CVD each year. It is well established that men and women differ not only in baseline cardiac parameters, but also in the clinical presentation, diagnosis and treatment outcomes of CVD. Women tend to develop heart disease later in life than men. This difference has been attributed to the loss of estrogen during the menopausal transition; however, the biological explanations for the sexual dimorphism in CVD are more complex and seem unlikely to be due to estrogen alone. The current controversy that has arisen regarding the effects of HRT on CVD in women is a case in point. In this review, the sex-based differences in cardiac (patho-) physiology are discussed with emphasis on the impact of sex hormones, hormone receptors and diet on heart disease.
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Affiliation(s)
- Poornima Bhupathy
- Department of Molecular, Cellular & Developmental Biology, University of Colorado, Boulder, CO 80309-80347, USA.
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28
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What we know and do not know about sex and cardiac disease. J Biomed Biotechnol 2010; 2010:562051. [PMID: 20445744 PMCID: PMC2860154 DOI: 10.1155/2010/562051] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 02/16/2010] [Indexed: 12/11/2022] Open
Abstract
Cardiovascular disease (CVD) remains the single leading cause of death in both men and women. A large proportion of the population with CVD will die with a diagnosis of congestive heart failure (CHF). It is becoming increasingly recognized that sex differences exist in the etiology, development, and outcome of CHF. For example, compared to male counterparts, women that present with CHF are typically older and have systolic cardiac function that is not impaired. Despite a growing body of literature addressing the underlying mechanisms of sex dimorphisms in cardiac disease, there remain significant inconsistencies reported in these studies. Given that the development of CHF results from the complex integration of genetic and nongenetic cues, it is not surprising that the elucidation and subsequent identification of molecular mechanisms remains unclear. In this review, key aspects of sex differences in CVD and CHF will be highlighted with an emphasis on some of the unanswered questions regarding these differences. The contention is presented that it becomes critical to reference cellular mechanisms within the context of each sex to better understand these sex dimorphisms.
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29
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Howlett SE. Age-associated changes in excitation-contraction coupling are more prominent in ventricular myocytes from male rats than in myocytes from female rats. Am J Physiol Heart Circ Physiol 2009; 298:H659-70. [PMID: 19966062 DOI: 10.1152/ajpheart.00214.2009] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We evaluated effects of age on components of excitation-contraction (EC) coupling in ventricular myocytes from male and female rats to examine sex differences in mechanisms responsible for age-related contractile dysfunction. Myocytes were isolated from anesthetized young adult (approximately 3 mo) and aged (approximately 24 mo) Fischer 344 rats. Ca(2+) concentrations and contractions were measured simultaneously (37 degrees C, 2 Hz). Fractional shortening declined with age in males (6.7 +/- 0.6% to 2.4 +/- 0.4%; P < 0.05), as did peak Ca(2+) transients (47.7 +/- 4.6 to 28.1 +/- 2.1 nM; P < 0.05) and Ca(2+) current densities (-7.7 +/- 0.7 to -6.2 +/- 0.5 pA/pF; P < 0.05). Although sarcoplasmic reticulum (SR) Ca(2+) content was similar regardless of age in males, EC coupling gain declined significantly with age to 55.8 +/- 7.8% of values in younger males. In contrast with results in males, contraction and Ca(2+) transient amplitudes were unaffected by age in females. Ca(2+) current density declined with age in females (-7.5 +/- 0.5 to -5.1 +/- 0.7 pA/pF; P < 0.05), but SR Ca(2+) content actually increased dramatically (49.0 +/- 7.5 to 147.3 +/- 28.5 nM; P < 0.05). Even so, EC coupling gain was not affected by age in female myocytes. Age also promoted hypertrophy of male myocytes more than female myocytes. Age and sex differences in EC coupling were largely maintained when conditioning pulse frequency was increased to 4 Hz. Contractions, Ca(2+) transients, and EC coupling gain were also smaller in young females than in young males. Thus age-dependent changes are more prominent in myocytes from males than females. Increased SR Ca(2+) content may compensate for reduced Ca(2+) current to preserve contractile function in aged females, which may limit the detrimental effects of age on cardiac contractile function.
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Affiliation(s)
- Susan E Howlett
- Department of Pharmacology and Division of Geriatric Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
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Quaile MP, Kubo H, Kimbrough CL, Douglas SA, Margulies KB. Direct inotropic effects of exogenous and endogenous urotensin-II: divergent actions in failing and nonfailing human myocardium. Circ Heart Fail 2009; 2:39-46. [PMID: 19808314 DOI: 10.1161/circheartfailure.107.748343] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Urotensin-II (U-II) is an endogenous peptide upregulated in failing hearts. To date, insights into the myocardial actions of U-II have been obscured by its potent vasoconstrictor effects and interspecies differences in physiological responses to U-II. METHODS AND RESULTS We examined the direct effects of exogenous U-II on in vitro contractility in nonfailing and failing human myocardial trabeculae (n=47). Rapid cooling contractures (RCC) were used to examine sarcoplasmic reticulum Ca(2+) load. In nonfailing myocardium, exogenous U-II increased developed force (DF), rates of force generation and decline and RCC amplitude suggesting increased sarcoplasmic reticulum Ca(2+) load. In isolated myocyte suspensions from nonfailing hearts, U-II increased phospholamban phosphorylation. In failing myocardium, exogenous U-II reduced DF and rates of force generation and decline without a significant change in RCC amplitude in trabeculae or a change in phospholamban phosphorylation in myocytes. To examine the effects of endogenous U-II, we administered the peptidic U-II receptor antagonist (UT-A) GSK248451A to isolated trabeculae. UT-A induced a decrease in DF in nonfailing myocardium and an increase in DF in failing myocardium. UT-A increased RCC amplitude slightly in both nonfailing and failing myocardium. During ongoing UT-A, exogenous U-II had little effect on DF and RCC amplitude, confirming effective receptor blockade. CONCLUSIONS U-II modulates contractility independent of vasoconstriction with opposite effects in failing and nonfailing hearts. Positive inotropic responses to UT-A alone suggests that increased endogenous U-II constrains contractility in failing hearts via an autocrine or paracrine mechanism. These findings support a potential therapeutic role for UT-A in heart failure.
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Affiliation(s)
- Michael P Quaile
- Department of Physiology, Temple University School of Medicine, Philadelphia, Pa, USA
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31
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Gender Differences in Cardiac Ischemic Injury and Protection—Experimental Aspects. Exp Biol Med (Maywood) 2009; 234:1011-9. [DOI: 10.3181/0812-mr-362] [Citation(s) in RCA: 99] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
This review summarizes some available information on gender differences of myocardial injury with particular attention to experimental approach. It has been observed that significant gender differences exist already in normal heart. They involve among others cardiac growth, contractile function, calcium metabolism and function of mitochondria. Differences, characteristic of the normal myocardium, generate the logical presumption of the different reaction of the male and female heart to various pathogenic factors. Most of the experimental studies confirm the clinical observations: increased resistance of the female heart to ischemia/reperfusion injury was shown in dogs, rats, mice and rabbits. Furthermore, gender differences in the ischemic tolerance of the adult myocardium can be influenced by interventions (e.g. hypoxia) imposed during the early phases of ontogenetic development. The already high tolerance of the adult female heart can be increased by adaptation to chronic hypoxia and ischemic preconditioning. It seems that the protective effect depends on age: it was absent in young, highly tolerant heart but it appeared with the decrease of natural resistance during aging. Both experimental and clinical studies have indicated that female gender influences favorably also the remodeling and the adaptive response to myocardial infarction. It follows from the data available that male and female heart differs significantly in many parameters under both physiological and pathological conditions. Detailed molecular and cellular mechanisms of these differences are still unknown; they involve genomic and non-genomic effects of sex steroid hormones, particularly the most frequently studied estrogens. The cardiovascular system is, however, influenced not only by estrogens but also by other sex hormones, e.g. androgens. Moreover, steroid hormone receptors do not act alone but interact with a broad array of co-regulatory proteins to alter transcription. The differences are so important that they deserve serious consideration in clinical practice in search for proper diagnostic and therapeutic procedures.
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32
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Lin J, Steenbergen C, Murphy E, Sun J. Estrogen receptor-beta activation results in S-nitrosylation of proteins involved in cardioprotection. Circulation 2009; 120:245-54. [PMID: 19581491 DOI: 10.1161/circulationaha.109.868729] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND It has been shown that the activation of estrogen receptor-beta (ER-beta) plays an important cardioprotective role against ischemia/reperfusion injury. However, the mechanism for this protection is not clear. We hypothesize that estrogen protects by ER-beta activation, which leads to S-nitrosylation (SNO) of key cardioprotective proteins. METHODS AND RESULTS We treated ovariectomized C57BL/6J mice with the ER-beta selective agonist 2,2-bis(4-hydroxyphenyl)-proprionitrile (DPN), 17beta-estradiol (E2), or vehicle using Alzet minipumps for 2 weeks. Isolated hearts were Langendorff perfused and subjected to ischemia and reperfusion. Compared with vehicle-treated hearts, DPN- and E2-treated hearts had significantly better postischemic functional recovery and decreased infarct size. To test the specificity of DPN, we treated ER-beta-knockout mice with DPN. However, no cardioprotective effect of DPN was found in ER-beta-knockout mice, indicating that the DPN-induced cardioprotection occurs through the activation of ER-beta. Using DyLight-maleimide fluors and a modified biotin switch method, we used a 2-dimensional DyLight fluorescence difference gel electrophoresis proteomic method to quantify differences in SNO of proteins. DPN- and E2-treated hearts showed an increase in SNO of a number of proteins. Interestingly, many of these proteins also had been shown to have increased SNO in preconditioned hearts. In addition, the DPN-induced cardioprotection and increased SNO were abolished by treatment with a nitric oxide synthase inhibitor. CONCLUSIONS The activation of ER-beta by DPN treatment leads to increased protein SNO and cardioprotection against ischemia/reperfusion injury, suggesting that long-term estrogen exposure protects hearts largely via activation of ER-beta and nitric oxide/SNO signaling.
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Ohno A, Ohya S, Yamamura H, Imaizumi Y. Regulation of ryanodine receptor-mediated Ca(2+) release in vas deferens smooth muscle cells. J Pharmacol Sci 2009; 110:78-86. [PMID: 19444000 DOI: 10.1254/jphs.09037fp] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Ca(2+) release from intracellular store sites via the ryanodine receptor (RyR) and hormonal regulation by flutamide, an androgen-receptor (AR) antagonist, on it were examined in vas deferens (VD) smooth muscle cells (SMCs). VD and VDSMCs were obtained from two groups of male rats that were treated p.o. with 100 mg/kg flutamide (Flu) or vehicle (Vehicle). Both spontaneous and caffeine-induced Ca(2+) releases were markedly smaller in single VDSMCs from Flu than in those from Vehicle. Interestingly, [Ca(2+)](i) rise by 100 muM norepinephrine in VDSMCs from Flu was larger than that in those from Vehicle. The contractions induced by direct electrical stimulation in tissue preparations from Flu showed lower susceptibility to 30 muM ryanodine than those from Vehicle. Real-time PCR analyses revealed that the transcripts of ryanodine receptor (RyR) type 2 and type 3 (RyR2 and RyR3) were expressed in VD and markedly reduced in Flu. The protein expression of total RyR was significantly reduced by flutamide treatment, but that of inositol 1,4,5-trisphosphate receptor (IP3R) was not affected. It can be strongly suggested that long term block of AR by flutamide reduced the expression of RyR and its contribution to the contraction, but not those of IP3R in VDSMCs.
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Affiliation(s)
- Akitoshi Ohno
- Department of Molecular and Cellular Pharmacology, Nagoya City University, Nagoya, Japan
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34
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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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Bell JR, Porrello ER, Huggins CE, Harrap SB, Delbridge LMD. The intrinsic resistance of female hearts to an ischemic insult is abrogated in primary cardiac hypertrophy. Am J Physiol Heart Circ Physiol 2008; 294:H1514-22. [PMID: 18245562 DOI: 10.1152/ajpheart.01283.2007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Important sex differences in cardiovascular disease outcomes exist, including conditions of hypertrophic cardiomyopathy and cardiac ischemia. Studies of sex differences in the extent to which load-independent (primary) hypertrophy modulates the response to ischemia-reperfusion (I/R) damage have not been characterized. We have previously described a model of primary genetic cardiac hypertrophy, the hypertrophic heart rat (HHR). In this study the sex differences in HHR cardiac function and responses to I/R [compared to control normal heart rat (NHR)] were investigated ex vivo. The ventricular weight index was markedly increased in HHR female (7.82 +/- 0.49 vs. 4.80 +/- 0.10 mg/g; P < 0.05) and male (5.76 +/- 0.22 vs. 4.62 +/- 0.07 mg/g; P < 0.05) hearts. Female hearts of both strains exhibited a reduced basal contractility compared with strain-matched males [maximum first derivative of pressure (dP/dt(max)): NHR, 4,036 +/- 171 vs. 4,258 +/- 152 mmHg/s; and HHR, 3,974 +/- 160 vs. 4,540 +/- 259 mmHg/s; P < 0.05]. HHR hearts were more susceptible to I/R (I = 25 min, and R = 30 min) injury than NHR hearts (decreased functional recovery, and increased lactate dehydrogenase efflux). Female NHR hearts exhibited a significantly greater recovery (dP/dt(max)) post-I/R relative to male NHR (95.0 +/- 12.2% vs. 60.5 +/- 9.4%), a resistance to postischemic dysfunction not evident in female HHR (29.0 +/- 5.6% vs. 25.9 +/- 6.3%). Ventricular fibrillation was suppressed, and expression levels of Akt and ERK1/2 were selectively elevated in female NHR hearts. Thus the occurrence of load-independent primary cardiac hypertrophy undermines the intrinsic resistance of female hearts to I/R insult, with the observed abrogation of endogenous cardioprotective signaling pathways consistent with a potential mechanistic role in this loss of protection.
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Affiliation(s)
- James R Bell
- Dept. of Physiology, Univ. of Melbourne, Parkville, Victoria 3010, Australia
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Nikolic I, Liu D, Bell JA, Collins J, Steenbergen C, Murphy E. Treatment with an estrogen receptor-beta-selective agonist is cardioprotective. J Mol Cell Cardiol 2007; 42:769-80. [PMID: 17362982 DOI: 10.1016/j.yjmcc.2007.01.014] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Revised: 01/17/2007] [Accepted: 01/29/2007] [Indexed: 11/29/2022]
Abstract
This study was designed to investigate whether treatment with an estrogen receptor-beta (ER-beta)-selective agonist (2,3-bis(4-hydroxyphenyl)-propionitrile, DPN) can provide cardioprotection in female mice lacking endogenous estrogen. To study the effect of ER-beta stimulation in ischemia-reperfusion injury, we treated ovariectomized (ovx) female mice with 0.1 mg/kg/day of 17beta-estradiol, 0.8 mg/kg/day of DPN, or vehicle for 2 weeks. Isolated hearts were Langendorff perfused for 25 min prior to a 1-min treatment with isoproterenol, followed by 20 min of normothermic global ischemia and 40 min of reperfusion. Left ventricular developed pressure (LVDP) and heart rate were measured. Recovery of function at the end of 40 min of reperfusion was expressed as a percentage of pre-ischemic rate pressure product (RPP=LVDP x heart rate). Hearts from ovx female mice had a significantly lower recovery of LVDP than the hearts from intact female mice (12.4+/-1.6% vs. 19.6+/-1.6%, p<0.05, respectively). Furthermore, hearts from ovx female mice treated with DPN exhibited significantly better functional recovery than hearts from either vehicle-treated ovx female mice (20.1+/-2.2% vs. 12.4+/-1.6%, p<0.05, respectively) or wild type male mice (20.1+/-2.2% vs. 6.4+/-0.6%, p<0.05, respectively). DPN did not increase uterine weight in ovx females compared to vehicle treatment. Gene profiling showed that treatment with DPN resulted in upregulation of a number of protective genes such as heat shock protein 70, the antiapoptotic protein, growth arrest and DNA damage 45 beta, and cyclooxygenase 2.
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Affiliation(s)
- Ivana Nikolic
- Laboratory of Signal Transduction, NIEHS, NIH, DHHS, Durham, NC, 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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