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Sidhu SK, Aleman JO, Heffron SP. Obesity Duration and Cardiometabolic Disease. Arterioscler Thromb Vasc Biol 2023; 43:1764-1774. [PMID: 37650325 PMCID: PMC10544713 DOI: 10.1161/atvbaha.123.319023] [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: 04/21/2023] [Accepted: 08/21/2023] [Indexed: 09/01/2023]
Abstract
Cardiovascular disease risk is known to be influenced by both the severity of a risk factor and the duration of exposure (eg, LDL [low-density lipoprotein] cholesterol, tobacco smoke). However, this concept has been largely neglected within the obesity literature. While obesity severity has been closely linked with cardiometabolic diseases, the risk of developing these conditions among those with obesity may be augmented by greater obesity duration over the life span. Few longitudinal or contemporary studies have investigated the influence of both factors in combination-cumulative obesity exposure-instead generally focusing on obesity severity, often at a single time point, given ease of use and lack of established methods to encapsulate duration. Our review focuses on what is known about the influence of the duration of exposure to excess adiposity within the obesity-associated cardiometabolic disease risk equation by means of summarizing the hypothesized mechanisms for and evidence surrounding the relationships of obesity duration with diverse cardiovascular and metabolic disease. Through the synthesis of the currently available data, we aim to highlight the importance of a better understanding of the influence of obesity duration in cardiovascular and metabolic disease pathogenesis. We underscore the clinical importance of aggressive early attention to obesity identification and intervention to prevent the development of chronic diseases that arise from exposure to excess body weight.
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Affiliation(s)
- Sharnendra K. Sidhu
- Department of Medicine, New York University Grossman School of Medicine, New York, NY, USA
| | - Jose O. Aleman
- Laboratory of Translational Obesity Research, Division of Endocrinology, Diabetes & Metabolism, New York University Grossman School of Medicine, New York, NY, USA
| | - Sean P. Heffron
- Center for the Prevention of Cardiovascular Disease, Leon H. Charney Division of Cardiology, NYU Langone Health, New York University Grossman School of Medicine, New York, NY, USA
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2
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Obesity-associated hyperleptinemia alters the gliovascular interface of the hypothalamus to promote hypertension. Cell Metab 2021; 33:1155-1170.e10. [PMID: 33951475 PMCID: PMC8183500 DOI: 10.1016/j.cmet.2021.04.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 02/27/2021] [Accepted: 04/12/2021] [Indexed: 12/21/2022]
Abstract
Pathologies of the micro- and macrovascular systems are a hallmark of the metabolic syndrome, which can lead to chronically elevated blood pressure. However, the underlying pathomechanisms involved still need to be clarified. Here, we report that an obesity-associated increase in serum leptin triggers the select expansion of the micro-angioarchitecture in pre-autonomic brain centers that regulate hemodynamic homeostasis. By using a series of cell- and region-specific loss- and gain-of-function models, we show that this pathophysiological process depends on hypothalamic astroglial hypoxia-inducible factor 1α-vascular endothelial growth factor (HIF1α-VEGF) signaling downstream of leptin signaling. Importantly, several distinct models of HIF1α-VEGF pathway disruption in astrocytes are protected not only from obesity-induced hypothalamic angiopathy but also from sympathetic hyperactivity or arterial hypertension. These results suggest that hyperleptinemia promotes obesity-induced hypertension via a HIF1α-VEGF signaling cascade in hypothalamic astrocytes while establishing a novel mechanistic link that connects hypothalamic micro-angioarchitecture with control over systemic blood pressure.
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Nakano T, Shiizaki K, Miura Y, Matsui M, Kosaki K, Mori S, Yamagata K, Maeda S, Kishi T, Usui N, Yoshida M, Onaka T, Mizukami H, Kaneda R, Karasawa K, Nitta K, Kurosu H, Kuro-O M. Increased fibroblast growth factor-21 in chronic kidney disease is a trade-off between survival benefit and blood pressure dysregulation. Sci Rep 2019; 9:19247. [PMID: 31848393 PMCID: PMC6917750 DOI: 10.1038/s41598-019-55643-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 11/27/2019] [Indexed: 12/21/2022] Open
Abstract
Circulating levels of fibroblast growth factor-21 (FGF21) start increasing in patients with chronic kidney disease (CKD) since early stages during the cause of disease progression. FGF21 is a liver-derived hormone that induces responses to stress through acting on hypothalamus to activate the sympathetic nervous system and the hypothalamus-pituitary-adrenal endocrine axis. However, roles that FGF21 plays in pathophysiology of CKD remains elusive. Here we show in mice that FGF21 is required to survive CKD but responsible for blood pressure dysregulation. When introduced with CKD, Fgf21−/− mice died earlier than wild-type mice. Paradoxically, these Fgf21−/− CKD mice escaped several complications observed in wild-type mice, including augmentation of blood pressure elevating response and activation of the sympathetic nervous system during physical activity and increase in serum noradrenalin and corticosterone levels. Supplementation of FGF21 by administration of an FGF21-expressing adeno-associated virus vector recapitulated these complications in wild-type mice and restored the survival period in Fgf21−/− CKD mice. In CKD patients, high serum FGF21 levels are independently associated with decreased baroreceptor sensitivity. Thus, increased FGF21 in CKD can be viewed as a survival response at the sacrifice of blood pressure homeostasis.
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Affiliation(s)
- Toshihiro Nakano
- Division of Anti-aging Medicine, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan.,Department of Medicine IV, Tokyo Women's Medical University, Tokyo, Japan
| | - Kazuhiro Shiizaki
- Division of Anti-aging Medicine, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
| | - Yutaka Miura
- Division of Anti-aging Medicine, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
| | - Masahiro Matsui
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
| | - Keisei Kosaki
- Faculty of Sport Sciences, Waseda University, Saitama, Japan.,Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan
| | - Shoya Mori
- Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan
| | - Kunihiro Yamagata
- Department of Nephrology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Seiji Maeda
- Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan
| | - Takuya Kishi
- Faculty of Health and Welfare Sciences in Fukuoka, International University of Health and Welfare, Fukuoka, Japan
| | - Naoki Usui
- Division of Brain and Neurophysiology, Department of Physiology, Jichi Medical University, Tochigi, Japan
| | - Masahide Yoshida
- Division of Brain and Neurophysiology, Department of Physiology, Jichi Medical University, Tochigi, Japan
| | - Tatsushi Onaka
- Division of Brain and Neurophysiology, Department of Physiology, Jichi Medical University, Tochigi, Japan
| | - Hiroaki Mizukami
- Division of Genetic Therapeutics, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
| | - Ruri Kaneda
- Division of Anti-aging Medicine, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
| | - Kazunori Karasawa
- Department of Medicine IV, Tokyo Women's Medical University, Tokyo, Japan
| | - Kosaku Nitta
- Department of Medicine IV, Tokyo Women's Medical University, Tokyo, Japan
| | - Hiroshi Kurosu
- Division of Anti-aging Medicine, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan
| | - Makoto Kuro-O
- Division of Anti-aging Medicine, Center for Molecular Medicine, Jichi Medical University, Tochigi, Japan. .,Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA. .,AMED-CREST, Japan Agency for Medical Research and Development, Tokyo, Japan.
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Sartori M, Conti FF, Dias DDS, Dos Santos F, Machi JF, Palomino Z, Casarini DE, Rodrigues B, De Angelis K, Irigoyen MC. Association between Diastolic Dysfunction with Inflammation and Oxidative Stress in Females ob/ob Mice. Front Physiol 2017; 8:572. [PMID: 28878683 PMCID: PMC5572327 DOI: 10.3389/fphys.2017.00572] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 07/24/2017] [Indexed: 12/31/2022] Open
Abstract
Objective: To evaluate autonomic and cardiovascular function, as well as inflammatory and oxidative stress markers in ob/ob female mice. Methods: Metabolic parameters, cardiac function, arterial pressure (AP), autonomic, hormonal, inflammatory, and oxidative stress markers were evaluated in 12-weeks female wild-type (WT group) and ob/ob mice (OB group). Results: OB animals showed increased body weight, blood glucose, and triglyceride levels, along with glucose intolerance, when compared to WT animals. Ejection fraction (EF) and AP were similar between groups; however, the OB group presented diastolic dysfunction, as well as an impairment on myocardial performance index. Moreover, the OB group exhibited important autonomic dysfunction and baroreflex sensitivity impairment, when compared to WT group. OB group showed increased Angiotensin II levels in heart and renal tissues; decreased adiponectin and increased inflammatory markers in adipose tissue and spleen. Additionally, OB mice presented a higher damage to proteins and lipoperoxidation and lower activity of antioxidant enzymes in kidney and heart. Correlations were found between autonomic dysfunction with angiotensin II and inflammatory mediators, as well as between inflammation and oxidative stress. Conclusions: Our results showed that female adult ob/ob mice presented discrete diastolic dysfunction accompanied by autonomic disorder, which is associated with inflammation and oxidative stress in these animals.
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Affiliation(s)
- Michelle Sartori
- Hypertension Unit, Heart Institute (InCor), Faculdade de Medicina da Universidade de São PauloSão Paulo, Brazil
| | - Filipe F Conti
- Translational Physiology Laboratory, Universidade Nove de JulhoSão Paulo, Brazil
| | | | - Fernando Dos Santos
- Hypertension Unit, Heart Institute (InCor), Faculdade de Medicina da Universidade de São PauloSão Paulo, Brazil
| | - Jacqueline F Machi
- Department of Integrative Immunological Cardiovascular Research, Institute for Neuro-Immune Medicine, Nova Southeastern UniversityFort Lauderdale, FL, United States
| | - Zaira Palomino
- Nephrology Division, Department of Medicine, Universidade Federal de São PauloSão Paulo, Brazil
| | - Dulce E Casarini
- Nephrology Division, Department of Medicine, Universidade Federal de São PauloSão Paulo, Brazil
| | - Bruno Rodrigues
- Department of Adapted Physical Activity, Faculty of Physical Education, Universidade Estadual de CampinasCampinas, Brazil
| | - Kátia De Angelis
- Translational Physiology Laboratory, Universidade Nove de JulhoSão Paulo, Brazil
| | - Maria-Claudia Irigoyen
- Hypertension Unit, Heart Institute (InCor), Faculdade de Medicina da Universidade de São PauloSão Paulo, Brazil
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Claflin KE, Sandgren JA, Lambertz AM, Weidemann BJ, Littlejohn NK, Burnett CML, Pearson NA, Morgan DA, Gibson-Corley KN, Rahmouni K, Grobe JL. Angiotensin AT1A receptors on leptin receptor-expressing cells control resting metabolism. J Clin Invest 2017; 127:1414-1424. [PMID: 28263184 DOI: 10.1172/jci88641] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 01/12/2017] [Indexed: 12/13/2022] Open
Abstract
Leptin contributes to the control of resting metabolic rate (RMR) and blood pressure (BP) through its actions in the arcuate nucleus (ARC). The renin-angiotensin system (RAS) and angiotensin AT1 receptors within the brain are also involved in the control of RMR and BP, but whether this regulation overlaps with leptin's actions is unclear. Here, we have demonstrated the selective requirement of the AT1A receptor in leptin-mediated control of RMR. We observed that AT1A receptors colocalized with leptin receptors (LEPRs) in the ARC. Cellular coexpression of AT1A and LEPR was almost exclusive to the ARC and occurred primarily within neurons expressing agouti-related peptide (AgRP). Mice lacking the AT1A receptor specifically in LEPR-expressing cells failed to show an increase in RMR in response to a high-fat diet and deoxycorticosterone acetate-salt (DOCA-salt) treatments, but BP control remained intact. Accordingly, loss of RMR control was recapitulated in mice lacking AT1A in AgRP-expressing cells. We conclude that angiotensin activates divergent mechanisms to control BP and RMR and that the brain RAS functions as a major integrator for RMR control through its actions at leptin-sensitive AgRP cells of the ARC.
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Lateef DM, Xiao C, Brychta RJ, Diedrich A, Schnermann J, Reitman ML. Bombesin-like receptor 3 regulates blood pressure and heart rate via a central sympathetic mechanism. Am J Physiol Heart Circ Physiol 2016; 310:H891-8. [PMID: 26801314 DOI: 10.1152/ajpheart.00963.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 01/22/2016] [Indexed: 02/07/2023]
Abstract
Bombesin-like receptor 3 (BRS-3) is an orphan G protein-coupled receptor that regulates energy expenditure, food intake, and body weight. We examined the effects of BRS-3 deletion and activation on blood pressure and heart rate. In free-living, telemetered Brs3 null mice the resting heart rate was 10% lower than wild-type controls, while the resting mean arterial pressure was unchanged. During physical activity, the heart rate and blood pressure increased more in Brs3 null mice, reaching a similar heart rate and higher mean arterial pressure than control mice. When sympathetic input was blocked with propranolol, the heart rate of Brs3 null mice was unchanged, while the heart rate in control mice was reduced to the level of the null mice. The intrinsic heart rate, measured after both sympathetic and parasympathetic blockade, was similar in Brs3 null and control mice. Intravenous infusion of the BRS-3 agonist MK-5046 increased mean arterial pressure and heart rate in wild-type but not in Brs3 null mice, and this increase was blocked by pretreatment with clonidine, a sympatholytic, centrally acting α2-adrenergic agonist. In anesthetized mice, hypothalamic infusion of MK-5046 also increased both mean arterial pressure and heart rate. Taken together, these data demonstrate that BRS-3 contributes to resting cardiac sympathetic tone, but is not required for activity-induced increases in heart rate and blood pressure. The data suggest that BRS-3 activation increases heart rate and blood pressure via a central sympathetic mechanism.
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Affiliation(s)
- Dalya M Lateef
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Cuiying Xiao
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Robert J Brychta
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - André Diedrich
- Autonomic Dysfunction Center, Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - Jurgen Schnermann
- Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland
| | - Marc L Reitman
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland;
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7
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Musicki B, Bella AJ, Bivalacqua TJ, Davies KP, DiSanto ME, Gonzalez-Cadavid NF, Hannan JL, Kim NN, Podlasek CA, Wingard CJ, Burnett AL. Basic Science Evidence for the Link Between Erectile Dysfunction and Cardiometabolic Dysfunction. J Sex Med 2015; 12:2233-55. [PMID: 26646025 DOI: 10.1111/jsm.13069] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Although clinical evidence supports an association between cardiovascular/metabolic diseases (CVMD) and erectile dysfunction (ED), scientific evidence for this link is incompletely elucidated. AIM This study aims to provide scientific evidence for the link between CVMD and ED. METHODS In this White Paper, the Basic Science Committee of the Sexual Medicine Society of North America assessed the current literature on basic scientific support for a mechanistic link between ED and CVMD, and deficiencies in this regard with a critical assessment of current preclinical models of disease. RESULTS A link exists between ED and CVMD on several grounds: the endothelium (endothelium-derived nitric oxide and oxidative stress imbalance); smooth muscle (SM) (SM abundance and altered molecular regulation of SM contractility); autonomic innervation (autonomic neuropathy and decreased neuronal-derived nitric oxide); hormones (impaired testosterone release and actions); and metabolics (hyperlipidemia, advanced glycation end product formation). CONCLUSION Basic science evidence supports the link between ED and CVMD. The Committee also highlighted gaps in knowledge and provided recommendations for guiding further scientific study defining this risk relationship. This endeavor serves to develop novel strategic directions for therapeutic interventions.
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Affiliation(s)
- Biljana Musicki
- The James Buchanan Brady Urological Institute and Department of Urology, The Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Anthony J Bella
- Division of Urology, Department of Surgery and Department of Neuroscience, Ottawa Hospital Research Institute at the University of Ottawa, Ottawa, ON, Canada
| | - Trinity J Bivalacqua
- The James Buchanan Brady Urological Institute and Department of Urology, The Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Kelvin P Davies
- Department of Urology, Albert Einstein College of Medicine, New York, NY, USA
| | - Michael E DiSanto
- Department of Surgery/Division of Urology, Cooper University Hospital, Camden, NJ, USA
| | - Nestor F Gonzalez-Cadavid
- Division of Urology, Department of Surgery, Harbor-UCLA Medical Center and Los Angeles Biomedical Research Institute, Torrance, CA, USA.,Department of Urology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Johanna L Hannan
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Noel N Kim
- Institute for Sexual Medicine, San Diego, CA, USA
| | - Carol A Podlasek
- Departments of Urology, Physiology, and Bioengineering, University of Illinois at Chicago, Chicago, IL, USA
| | - Christopher J Wingard
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Arthur L Burnett
- The James Buchanan Brady Urological Institute and Department of Urology, The Johns Hopkins School of Medicine, Baltimore, MD, USA
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8
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Heart rate reduction and longevity in mice. Basic Res Cardiol 2015; 110:2. [PMID: 25589054 DOI: 10.1007/s00395-014-0460-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 12/03/2014] [Accepted: 12/19/2014] [Indexed: 12/19/2022]
Abstract
Heart rate correlates inversely with life span across all species, including humans. In patients with cardiovascular disease, higher heart rate is associated with increased mortality, and such patients benefit from pharmacological heart rate reduction. However, cause-and-effect relationships between heart rate and longevity, notably in healthy individuals, are not established. We therefore prospectively studied the effects of a life-long pharmacological heart rate reduction on longevity in mice. We hypothesized, that the total number of cardiac cycles is constant, and that a 15% heart rate reduction might translate into a 15% increase in life span. C57BL6/J mice received either placebo or ivabradine at a dose of 50 mg/kg/day in drinking water from 12 weeks to death. Heart rate and body weight were monitored. Autopsy was performed on all non-autolytic cadavers, and parenchymal organs were evaluated macroscopically. Ivabradine reduced heart rate by 14% (median, interquartile range 12-15%) throughout life, and median life span was increased by 6.2% (p = 0.01). Body weight and macroscopic findings were not different between placebo and ivabradine. Life span was not increased to the same extent as heart rate was reduced, but nevertheless significantly prolonged by 6.2%.
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9
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Cavalera M, Wang J, Frangogiannis NG. Obesity, metabolic dysfunction, and cardiac fibrosis: pathophysiological pathways, molecular mechanisms, and therapeutic opportunities. Transl Res 2014; 164:323-35. [PMID: 24880146 PMCID: PMC4180761 DOI: 10.1016/j.trsl.2014.05.001] [Citation(s) in RCA: 177] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 04/28/2014] [Accepted: 05/03/2014] [Indexed: 02/09/2023]
Abstract
Cardiac fibrosis is strongly associated with obesity and metabolic dysfunction and may contribute to the increased incidence of heart failure, atrial arrhythmias, and sudden cardiac death in obese subjects. This review discusses the evidence linking obesity and myocardial fibrosis in animal models and human patients, focusing on the fundamental pathophysiological alterations that may trigger fibrogenic signaling, the cellular effectors of fibrosis, and the molecular signals that may regulate the fibrotic response. Obesity is associated with a wide range of pathophysiological alterations (such as pressure and volume overload, metabolic dysregulation, neurohumoral activation, and systemic inflammation); their relative role in mediating cardiac fibrosis is poorly defined. Activation of fibroblasts likely plays a major role in obesity-associated fibrosis; however, inflammatory cells, cardiomyocytes, and vascular cells may also contribute to fibrogenic signaling. Several molecular processes have been implicated in regulation of the fibrotic response in obesity. Activation of the renin-angiotensin-aldosterone system, induction of transforming growth factor β, oxidative stress, advanced glycation end-products, endothelin 1, Rho-kinase signaling, leptin-mediated actions, and upregulation of matricellular proteins (such as thrombospondin 1) may play a role in the development of fibrosis in models of obesity and metabolic dysfunction. Moreover, experimental evidence suggests that obesity and insulin resistance profoundly affect the fibrotic and remodeling response after cardiac injury. Understanding the pathways implicated in obesity-associated fibrosis may lead to the development of novel therapies to prevent heart failure and attenuate postinfarction cardiac remodeling in patients with obesity.
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Affiliation(s)
- Michele Cavalera
- Division of Cardiology, Department of Medicine, The Wilf Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, New York
| | - Junhong Wang
- Division of Cardiology, Department of Medicine, The Wilf Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, New York
| | - Nikolaos G Frangogiannis
- Division of Cardiology, Department of Medicine, The Wilf Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, New York.
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10
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Mugabo P, Raji IA. Effects of aqueous leaf extract of Asystasia gangetica on the blood pressure and heart rate in male spontaneously hypertensive Wistar rats. Altern Ther Health Med 2013; 13:283. [PMID: 24160568 PMCID: PMC3815069 DOI: 10.1186/1472-6882-13-283] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 10/24/2013] [Indexed: 12/19/2022]
Abstract
Background Asystasia gangentica (A. gangetica) belongs to the family Acanthaceae. It is used to treat hypertension, rheumatism, asthma, diabetes mellitus, and as an anthelmintic in South Africa, India, Cameroun, Nigeria, and Kenya respectively. It has also been reported to inhibit the angiotensin I converting enzyme (ACE) in-vitro. Therefore, the aim of this study is to investigate the in-vivo effect of aqueous leaf extract (ALE) of A. gangetica on the blood pressure (BP) and heart rate (HR) in anaesthetized male spontaneously hypertensive rats (SHR); and to elucidate possible mechanism(s) by which it acts. Methods The ALE of A. gangetica (10–400 mg/kg), angiotensin I human acetate salt hydrate (ANG I, 3.1–100 μg/kg) and angiotensin II human (ANG II, 3.1–50 μg/kg) were administered intravenously. The BP and HR were measured via a pressure transducer connecting the femoral artery to a Powerlab and a computer for recording. Results A. gangetica significantly (p<0.05), and dose-dependently reduced the systolic, diastolic, and mean arterial BP. The significant (p<0.05) reductions in HR were not dose-dependent. Both ANG I and ANG II increased the BP dose-dependently. Co-infusion of A. gangetica (200 mg/kg) with either ANG I or ANG II significantly (p<0.05) suppressed the hypertensive effect of both ANG I and ANG II respectively, and was associated with reductions in HR. Conclusions A. gangetica ALE reduced BP and HR in the SHR. The reduction in BP may be a result of actions of the ALE on the ACE, the ANG II receptors and the heart rate.
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11
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Li B, Shi Z, Cassaglia PA, Brooks VL. Leptin acts in the forebrain to differentially influence baroreflex control of lumbar, renal, and splanchnic sympathetic nerve activity and heart rate. Hypertension 2013; 61:812-9. [PMID: 23424232 DOI: 10.1161/hypertensionaha.111.00518] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Although leptin is known to increase sympathetic nerve activity (SNA), we tested the hypothesis that leptin also enhances baroreflex control of SNA and heart rate (HR). Using α-chloralose anesthetized male rats, mean arterial pressure (MAP), HR, lumbar SNA (LSNA), splanchnic SNA (SSNA), and renal SNA (RSNA) were recorded before and for 2 hours after lateral cerebroventricular leptin or artificial cerebrospinal fluid administration. Baroreflex function was assessed using a 4-parameter sigmoidal fit of HR and SNA responses to slow ramp (3-5 minutes) changes in MAP, induced by intravenous infusion of nitroprusside and phenylephrine. Leptin (3 μg) increased (P<0.05) basal LSNA, SSNA, RSNA, HR, and MAP, and the LSNA, SSNA, RSNA, and HR baroreflex maxima. Leptin also increased gain of baroreflex control of LSNA and RSNA, but not of SSNA or HR. The elevations in HR were eliminated by pretreatment with methscopalamine, to block parasympathetic nerve activity; however, after cardiac sympathetic blockade with atenolol, leptin still increased basal HR and MAP and the HR baroreflex maximum and minimum. Leptin (1.5 μg) also increased LSNA and enhanced LSNA baroreflex gain and maximum, but did not alter MAP, HR, or the HR baroreflex. Lateral cerebroventricular artificial cerebrospinal fluid had no effects. Finally, to test whether leptin acts in the brain stem, leptin (3 μg) was infused into the 4th ventricle; however, no significant changes were observed. In conclusion, leptin acts in the forebrain to differentially influence baroreflex control of LSNA, RSNA, SSNA, and HR, with the latter action mediated via suppression of parasympathetic nerve activity.
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Affiliation(s)
- Baoxin Li
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR 97239, USA
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12
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Mann MC, Exner DV, Hemmelgarn BR, Turin TC, Sola DY, Ahmed SB. Impact of gender on the cardiac autonomic response to angiotensin II in healthy humans. J Appl Physiol (1985) 2012; 112:1001-7. [DOI: 10.1152/japplphysiol.01207.2011] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Premenopausal women have a lower risk of cardiovascular disease (CVD) compared with men of a similar age. Furthermore, the regulation of factors that influence CVD appears to differ between the sexes, including control of the autonomic nervous system (ANS) and the renin-angiotensin system. We examined the cardiac ANS response to angiotensin II (Ang II) challenge in healthy subjects to determine whether differences in women and men exist. Thirty-six healthy subjects (21 women, 15 men, age 38 ± 2 years) were studied in a high-salt balance. Heart-rate variability (HRV) was calculated by spectral power analysis [low-frequency (LF) sympathetic modulation, high-frequency (HF) parasympathetic/vagal modulation, and LF:HF as a measure of overall ANS balance]. HRV was assessed at baseline and in response to graded Ang II infusions (3 ng·kg−1·min−1 × 30 min; 6 ng·kg−1·min−1 × 30 min). Cardiac ANS tone did not change significantly in women after each Ang II dose [3 ng·kg−1·min−1 mean change (Δ)LF:HF (mean ± SE) 0.5 ± 0.3, P = 0.8, vs. baseline; 6 ng·kg−1·min−1 ΔLF:HF (mean ± SE) 0.5 ± 0.4, P = 0.4, vs. baseline], whereas men exhibited an unfavorable shift in overall cardiac ANS activity in response to Ang II (ΔLF:HF 2.6 ± 0.2, P = 0.01, vs. baseline; P = 0.02 vs. female response). This imbalance in sympathovagal tone appeared to be largely driven by a withdrawal in cardioprotective vagal activity in response to Ang II challenge [ΔHF normalized units (nu), −5.8 ± 2.9, P = 0.01, vs. baseline; P = 0.006 vs. women] rather than an increase in sympathetic activity (ΔLF nu, −4.5 ± 5.7, P = 0.3, vs. baseline; P = 0.5 vs. women). Premenopausal women maintain cardiac ANS tone in response to Ang II challenge, whereas similarly aged men exhibit an unfavorable shift in cardiovagal activity. Understanding the role of gender in ANS modulation may help guide risk-reduction strategies in high-risk CVD populations.
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Affiliation(s)
- M. C. Mann
- Faculty of Medicine, University of Calgary
- Libin Cardiovascular Institute of Alberta, Calgary; and
| | - D. V. Exner
- Faculty of Medicine, University of Calgary
- Libin Cardiovascular Institute of Alberta, Calgary; and
| | - B. R. Hemmelgarn
- Faculty of Medicine, University of Calgary
- Libin Cardiovascular Institute of Alberta, Calgary; and
- Alberta Kidney Disease Network, Alberta, Canada
| | | | - D. Y. Sola
- Libin Cardiovascular Institute of Alberta, Calgary; and
| | - S. B. Ahmed
- Faculty of Medicine, University of Calgary
- Libin Cardiovascular Institute of Alberta, Calgary; and
- Alberta Kidney Disease Network, Alberta, Canada
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13
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McCully BH, Brooks VL, Andresen MC. Diet-induced obesity severely impairs myelinated aortic baroreceptor reflex responses. Am J Physiol Heart Circ Physiol 2012; 302:H2083-91. [PMID: 22408022 DOI: 10.1152/ajpheart.01200.2011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Diet-induced obesity (DIO) attenuates the arterial cardiac baroreceptor reflex, but the mechanisms and sites of action are unknown. This study tested the hypothesis that DIO impairs central aortic baroreceptor pathways. Normal chow control (CON) and high-fat-chow obesity-resistant (OR) and obesity-prone (OP) rats were anesthetized (inactin, 120 mg/kg) and underwent sinoaortic denervation. The central end of the aortic depressor nerve (ADN) was electrically stimulated to generate frequency-dependent baroreflex curves (5-100 Hz) during selective activation of myelinated (A-fiber) or combined (A- and C-fiber) ADN baroreceptors. A mild stimulus (1 V) that activates only A-fiber ADN baroreceptors induced robust, frequency-dependent depressor and bradycardic responses in CON and OR rats, but these responses were completely abolished in OP rats. Maximal activation of A fibers (3 V) elicited frequency-dependent reflexes in all groups, but a dramatic deficit was still present in OP rats. Activation of all ADN baroreceptors (20 V) evoked even larger reflex responses. Depressor responses were nearly identical among groups, but OP rats still exhibited attenuated bradycardia. In separate groups of rats, the reduced heart rate (HR) response to maximal activation of ADN A fibers (3 V) persisted in OP rats following pharmacological blockade of β(1)-adrenergic or muscarinic receptors, suggesting deficits in both parasympathetic nervous system (PNS) and sympathetic nervous system (SNS) reflex pathways. However, the bradycardic responses to direct efferent vagal stimulation were similar among groups. Taken together, our data suggest that DIO severely impairs the central processing of myelinated aortic baroreceptor control of HR, including both PNS and SNS components.
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Affiliation(s)
- Belinda H McCully
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, OR 97239, USA.
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14
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Raji IA, Mugabo P, Obikeze K. Effect of Tulbaghia violacea on the blood pressure and heart rate in male spontaneously hypertensive Wistar rats. JOURNAL OF ETHNOPHARMACOLOGY 2012; 140:98-106. [PMID: 22222281 DOI: 10.1016/j.jep.2011.12.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2011] [Revised: 12/15/2011] [Accepted: 12/20/2011] [Indexed: 05/31/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Tulbaghia violacea Harv. (Alliaceae) is a small bulbous herb which belongs to the family Alliaceae, most commonly associated with onions and garlic. In South Africa, this herb has been traditionally used in the treatment of various ailments, including fever, colds, asthma, paralysis, hypertension and stomach problems. The aim of this study was to evaluate the effect of methanol leaf extracts (MLE) of Tulbaghia violacea on the blood pressure (BP) and heart rate (HR) in anaesthetized male spontaneously hypertensive rats; and to find out the mechanism(s) by which it acts. MATERIALS AND METHODS The MLE of Tulbaghia violacea (5-150mg/kg), angiotensin I human acetate salt hydrate (ang I, 3.1-100μg/kg), angiotensin II human (ang II, 3.1-50μg/kg), phenylephrine hydrochloride (phenylephrine, 0.01-0.16mg/kg) and dobutamine hydrochloride (dobutamine, 0.2-10.0μg/kg) were infused intravenously, while the BP and HR were measured via a pressure transducer connecting the femoral artery and the Powerlab. RESULTS Tulbaghia violacea significantly (p<0.01) reduced the systolic, diastolic, and mean arterial BP; and HR dose-dependently. Ang I, ang II, phenylephrine and dobutamine all increased the BP dose-dependently. The hypertensive effect of ang I and the HR-increasing effect of dobutamine were significantly (p<0.01) decreased by their co-infusion with Tulbaghia violacea (60mg/kg). However, the co-infusion of ang II or phenylephrine with Tulbaghia violacea (60mg/kg) did not produce any significant change in BP or HR when compared to the infusion of either agent alone in the same animal. CONCLUSIONS Tulbaghia violacea reduced BP and HR in the SHR. The reduction in BP may be due to actions of the MLE on the ang I converting enzyme (ACE) and β(1) adrenoceptors.
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Affiliation(s)
- Ismaila A Raji
- Discipline of Pharmacology, School of Pharmacy, University of the Western Cape, Private Bag X17, Bellville 7535, South Africa.
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15
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Essick EE, Sam F. Cardiac hypertrophy and fibrosis in the metabolic syndrome: a role for aldosterone and the mineralocorticoid receptor. Int J Hypertens 2011; 2011:346985. [PMID: 21747976 PMCID: PMC3124304 DOI: 10.4061/2011/346985] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 03/07/2011] [Indexed: 12/28/2022] Open
Abstract
Obesity and hypertension, major risk factors for the metabolic syndrome, render individuals susceptible to an increased risk of cardiovascular complications, such as adverse cardiac remodeling and heart failure. There has been much investigation into the role that an increase in the renin-angiotensin-aldosterone system (RAAS) plays in the pathogenesis of metabolic syndrome and in particular, how aldosterone mediates left ventricular hypertrophy and increased cardiac fibrosis via its interaction with the mineralocorticoid receptor (MR). Here, we review the pertinent findings that link obesity with elevated aldosterone and the development of cardiac hypertrophy and fibrosis associated with the metabolic syndrome. These studies illustrate a complex cross-talk between adipose tissue, the heart, and the adrenal
cortex. Furthermore, we discuss findings from our laboratory that suggest that cardiac hypertrophy and fibrosis in the metabolic syndrome may involve cross-talk between aldosterone and adipokines (such as adiponectin).
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Affiliation(s)
- Eric E Essick
- Whitaker Cardiovascular Institute, Boston University School of Medicine 715 Albany Street, W507 Boston, MA 02118, USA
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16
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Hilzendeger AM, Morais RL, Todiras M, Plehm R, da Costa Goncalves A, Qadri F, Araujo RC, Gross V, Nakaie CR, Casarini DE, Carmona AK, Bader M, Pesquero JB. Leptin regulates ACE activity in mice. J Mol Med (Berl) 2010; 88:899-907. [PMID: 20614101 DOI: 10.1007/s00109-010-0649-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 06/10/2010] [Accepted: 06/17/2010] [Indexed: 02/06/2023]
Abstract
Leptin is a hormone related to metabolism. It also influences blood pressure, but the mechanisms triggered in this process are not yet elucidated. Angiotensin-I converting enzyme (ACE) regulates cardiovascular functions and recently has been associated with metabolism control and obesity. Here, we used ob/ob mice, a model lacking leptin, to answer the question whether ACE and leptin could interact to influence blood pressure, thereby linking the renin-angiotensin system and obesity. These mice are obese and diabetic but have normal 24 h mean arterial pressure. Our results show that plasma and lung ACE activities as well as ACE mRNA expression were significantly decreased in ob/ob mice. In agreement with these findings, the hypotensive effect produced by enalapril administration was attenuated in the obese mice. Plasma renin, angiotensinogen, angiotensin I, bradykinin, and angiotensin 1-7 were increased, whereas plasma angiotensin II concentration was unchanged in obese mice. Chronic infusion of leptin increased renin activity and angiotensin II concentration in both groups and increased ACE activity in ob/ob mice. Acute leptin infusion restored ACE activity in leptin-deficient mice. Moreover, the effect of an ACE inhibitor on blood pressure was not changed in ob/+ mice during leptin treatment but increased four times in obese mice. In summary, our findings show that the renin-angiotensin system is altered in ob/ob mice, with markedly reduced ACE activity, which suggests a possible connection between the renin-angiotensin system and leptin. These results point to an important interplay between the angiotensinergic and the leptinergic systems, which may play a role in the pathogenesis of obesity, hypertension, and metabolic syndrome.
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Affiliation(s)
- Aline Mourao Hilzendeger
- Department of Biophysics, Escola Paulista de Medicina, Federal University of São Paulo, 04023-062 São Paulo, SP, Brazil
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