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Hiraki N, Nagoshi T, Okuyama T, Tanaka TD, Oi Y, Kashiwagi Y, Inoue Y, Ogawa K, Minai K, Ogawa T, Kawai M, Yoshimura M. Inhibitory action of B-type natriuretic peptide on adrenocorticotropic hormone in patients with acute coronary syndrome. Am J Physiol Heart Circ Physiol 2023; 325:H856-H865. [PMID: 37594489 DOI: 10.1152/ajpheart.00315.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/10/2023] [Accepted: 08/15/2023] [Indexed: 08/19/2023]
Abstract
In addition to the classical actions of hemodynamic regulation, natriuretic peptides (NPs) interact with various neurohumoral factors that are deeply involved in the pathophysiology of cardiovascular diseases. However, their effects on the hypothalamic-pituitary-adrenal (HPA) axis, which is activated under acute high-stress conditions in acute coronary syndrome (ACS), remain largely unknown. We investigated the impact of plasma B-type NP (BNP) on plasma adrenocorticotropic hormone (ACTH)-cortisol levels during the acute phase of ACS ischemic attacks. The study population included 436 consecutive patients with ACS for whom data were collected during emergency cardiac catheterization. Among them, biochemical data after acute-phase treatment were available in 320 cases, defined as the ACS-remission phase (ACS-rem). Multiple regression analyses revealed that plasma BNP levels were significantly negatively associated with plasma ACTH levels only during ACS attacks (P < 0.001), but not in ACS-rem, whereas plasma BNP levels were not significantly associated with plasma cortisol levels at any point. Accordingly, covariance structure analyses were performed to clarify the direct contribution of BNP to ACTH by excluding other confounding factors, confirming that BNP level was negatively correlated with ACTH level only during ACS attacks (β = -0.152, P = 0.002), whereas BNP did not significantly affect ACTH in ACS-rem. In conclusion, despite the lack of a significant direct association with cortisol levels, BNP negatively regulated ACTH levels during the acute phase of an ACS attack in which the HPA axis ought to be activated. NP may alleviate the acute stress response induced by severe ischemic attacks in patients with ACS.NEW & NOTEWORTHY BNP negatively regulates ACTH during a severe ischemic attack of ACS in which hypothalamic-pituitary-adrenal axis ought to be activated, indicating an important role of natriuretic peptides as a mechanism of adaptation to acute critical stress conditions in humans.
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Affiliation(s)
- Nana Hiraki
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Tomohisa Nagoshi
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Toraaki Okuyama
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Toshikazu D Tanaka
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Yuhei Oi
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Yusuke Kashiwagi
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Yasunori Inoue
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kazuo Ogawa
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Kosuke Minai
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Takayuki Ogawa
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Makoto Kawai
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
| | - Michihiro Yoshimura
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan
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Parksook WW, Williams GH. Aldosterone and cardiovascular diseases. Cardiovasc Res 2023; 119:28-44. [PMID: 35388416 DOI: 10.1093/cvr/cvac027] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 12/07/2021] [Accepted: 12/28/2021] [Indexed: 11/12/2022] Open
Abstract
Aldosterone's role in the kidney and its pathophysiologic actions in hypertension are well known. However, its role or that of its receptor [minieralocorticoid receptor (MR)] in other cardiovascular (CV) disease are less well described. To identify their potential roles in six CV conditions (heart failure, myocardial infarction, atrial fibrillation, stroke, atherosclerosis, and thrombosis), we assessed these associations in the following four areas: (i) mechanistic studies in rodents and humans; (ii) pre-clinical studies of MR antagonists; (iii) clinical trials of MR antagonists; and (iv) genetics. The data were acquired from an online search of the National Library of Medicine using the PubMed search engine from January 2011 through June 2021. There were 3702 publications identified with 200 publications meeting our inclusion and exclusion criteria. Data strongly supported an association between heart failure and dysregulated aldosterone/MR. This association is not surprising given aldosterone/MR's prominent role in regulating sodium/volume homeostasis. Atrial fibrillation and myocardial infarction are also associated with dysregulated aldosterone/MR, but less strongly. For the most part, the data were insufficient to determine whether there was a relationship between atherosclerosis, stroke, or thrombosis and aldosterone/MR dysregulation. This review clearly documented an expanding role for aldosterone/MR's dysregulation in CV diseases beyond hypertension. How expansive it might be is limited by the currently available data. It is anticipated that with an increased focus on aldosterone/MR's potential roles in these diseases, additional clinical and pre-clinical data will clarify these relationships, thereby, opening approaches to use modulators of aldosterone/MR's action to more precisely treat these CV conditions.
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Affiliation(s)
- Wasita W Parksook
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Division of Endocrinology and Metabolism, Faculty of Medicine, Chulalongkorn University, and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
- Division of General Internal Medicine, Faculty of Medicine, Chulalongkorn University, and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok, Thailand
| | - Gordon H Williams
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Xia H, Zahra A, Jia M, Wang Q, Wang Y, Campbell SL, Wu J. Na +/H + Exchanger 1, a Potential Therapeutic Drug Target for Cardiac Hypertrophy and Heart Failure. Pharmaceuticals (Basel) 2022; 15:ph15070875. [PMID: 35890170 PMCID: PMC9318128 DOI: 10.3390/ph15070875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/07/2022] [Accepted: 07/12/2022] [Indexed: 01/27/2023] Open
Abstract
Cardiac hypertrophy is defined as increased heart mass in response to increased hemodynamic requirements. Long-term cardiac hypertrophy, if not counteracted, will ultimately lead to heart failure. The incidence of heart failure is related to myocardial infarction, which could be salvaged by reperfusion and ultimately invites unfavorable myocardial ischemia-reperfusion injury. The Na+/H+ exchangers (NHEs) are membrane transporters that exchange one intracellular proton for one extracellular Na+. The first discovered NHE isoform, NHE1, is expressed almost ubiquitously in all tissues, especially in the myocardium. During myocardial ischemia-reperfusion, NHE1 catalyzes increased uptake of intracellular Na+, which in turn leads to Ca2+ overload and subsequently myocardial injury. Numerous preclinical research has shown that NHE1 is involved in cardiac hypertrophy and heart failure, but the exact molecular mechanisms remain elusive. The objective of this review is to demonstrate the potential role of NHE1 in cardiac hypertrophy and heart failure and investigate the underlying mechanisms.
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Affiliation(s)
- Huiting Xia
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China; (H.X.); (A.Z.)
| | - Aqeela Zahra
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China; (H.X.); (A.Z.)
| | - Meng Jia
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China; (M.J.); (Q.W.)
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Disease, Beijing 100070, China
| | - Qun Wang
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China; (M.J.); (Q.W.)
- National Clinical Research Center for Neurological Disease, Beijing 100070, China
| | - Yunfu Wang
- Taihe Hospital, Hubei University of Medicine, Shiyan 440070, China;
| | - Susan L. Campbell
- Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, USA;
| | - Jianping Wu
- School of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, China; (H.X.); (A.Z.)
- Beijing Tiantan Hospital, Capital Medical University, Beijing 100070, China; (M.J.); (Q.W.)
- Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100070, China
- National Clinical Research Center for Neurological Disease, Beijing 100070, China
- Correspondence:
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Lorenzo-Almorós A, Cepeda-Rodrigo J, Lorenzo Ó. Diabetic cardiomyopathy. Rev Clin Esp 2022; 222:100-111. [DOI: 10.1016/j.rceng.2019.10.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Accepted: 10/21/2019] [Indexed: 12/24/2022]
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de las Heras N, Galiana A, Ballesteros S, Olivares-Álvaro E, Fuller PJ, Lahera V, Martín-Fernández B. Proanthocyanidins Maintain Cardiac Ionic Homeostasis in Aldosterone-Induced Hypertension and Heart Failure. Int J Mol Sci 2021; 22:ijms22179602. [PMID: 34502509 PMCID: PMC8431754 DOI: 10.3390/ijms22179602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/31/2021] [Accepted: 08/31/2021] [Indexed: 11/16/2022] Open
Abstract
Excess aldosterone promotes pathological remodeling of the heart and imbalance in cardiac ion homeostasis of sodium, potassium and calcium. Novel treatment with proanthocyanidins in aldosterone-treated rats has resulted in downregulation of cardiac SGK1, the main genomic aldosterone-induced intracellular mediator of ion handling. It therefore follows that proanthocyanidins could be modulating cardiac ion homeostasis in aldosterone-treated rats. Male Wistar rats received aldosterone (1 mg kg−1 day−1) +1% NaCl for three weeks. Half of the animals in each group were simultaneously treated with the proanthocyanidins-rich extract (80% w/w) (PRO80, 5 mg kg−1 day−1). PRO80 prevented cardiac hypertrophy and decreased calcium content. Expression of ion channels (ROMK, NHE1, NKA and NCX1) and calcium transient mediators (CAV1.2, pCaMKII and oxCaMKII) were reduced by PRO80 treatment in aldosterone-treated rats. To conclude, our data indicate that PRO80 may offer an alternative treatment to conventional MR-blockade in the prevention of aldosterone-induced cardiac pathology.
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Affiliation(s)
- Natalia de las Heras
- Department of Physiology, Faculty of Medicine, Plaza Ramón y Cajal, s/n. Universidad Complutense, 28040 Madrid, Spain; (N.d.l.H.); (A.G.); (S.B.); (E.O.-Á.); (V.L.)
| | - Adrián Galiana
- Department of Physiology, Faculty of Medicine, Plaza Ramón y Cajal, s/n. Universidad Complutense, 28040 Madrid, Spain; (N.d.l.H.); (A.G.); (S.B.); (E.O.-Á.); (V.L.)
| | - Sandra Ballesteros
- Department of Physiology, Faculty of Medicine, Plaza Ramón y Cajal, s/n. Universidad Complutense, 28040 Madrid, Spain; (N.d.l.H.); (A.G.); (S.B.); (E.O.-Á.); (V.L.)
| | - Elena Olivares-Álvaro
- Department of Physiology, Faculty of Medicine, Plaza Ramón y Cajal, s/n. Universidad Complutense, 28040 Madrid, Spain; (N.d.l.H.); (A.G.); (S.B.); (E.O.-Á.); (V.L.)
| | - Peter J. Fuller
- Centre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Clayton, VIC 3168, Australia;
| | - Vicente Lahera
- Department of Physiology, Faculty of Medicine, Plaza Ramón y Cajal, s/n. Universidad Complutense, 28040 Madrid, Spain; (N.d.l.H.); (A.G.); (S.B.); (E.O.-Á.); (V.L.)
| | - Beatriz Martín-Fernández
- Department of Physiology, Faculty of Medicine, Plaza Ramón y Cajal, s/n. Universidad Complutense, 28040 Madrid, Spain; (N.d.l.H.); (A.G.); (S.B.); (E.O.-Á.); (V.L.)
- Department of Molecular Biology, Faculty of Biology, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
- Correspondence: ; Tel.: +34-987-291-000 (ext. 3650)
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Trum M, Riechel J, Wagner S. Cardioprotection by SGLT2 Inhibitors-Does It All Come Down to Na +? Int J Mol Sci 2021; 22:ijms22157976. [PMID: 34360742 PMCID: PMC8347698 DOI: 10.3390/ijms22157976] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 07/22/2021] [Accepted: 07/22/2021] [Indexed: 12/15/2022] Open
Abstract
Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are emerging as a new treatment strategy for heart failure with reduced ejection fraction (HFrEF) and—depending on the wistfully awaited results of two clinical trials (DELIVER and EMPEROR-Preserved)—may be the first drug class to improve cardiovascular outcomes in patients suffering from heart failure with preserved ejection fraction (HFpEF). Proposed mechanisms of action of this class of drugs are diverse and include metabolic and hemodynamic effects as well as effects on inflammation, neurohumoral activation, and intracellular ion homeostasis. In this review we focus on the growing body of evidence for SGLT2i-mediated effects on cardiac intracellular Na+ as an upstream mechanism. Therefore, we will first give a short overview of physiological cardiomyocyte Na+ handling and its deterioration in heart failure. On this basis we discuss the salutary effects of SGLT2i on Na+ homeostasis by influencing NHE1 activity, late INa as well as CaMKII activity. Finally, we highlight the potential relevance of these effects for systolic and diastolic dysfunction as well as arrhythmogenesis.
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7
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Ennis IL, Pérez NG. Cardiac Mineralocorticoid Receptor and the Na +/H + Exchanger: Spilling the Beans. Front Cardiovasc Med 2021; 7:614279. [PMID: 33553262 PMCID: PMC7854694 DOI: 10.3389/fcvm.2020.614279] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 12/01/2020] [Indexed: 01/08/2023] Open
Abstract
Current evidence reveals that cardiac mineralocorticoid receptor (MR) activation following myocardial stretch plays an important physiological role in adapting developed force to sudden changes in hemodynamic conditions. Its underlying mechanism involves a previously unknown nongenomic effect of the MR that triggers redox-mediated Na+/H+ exchanger (NHE1) activation, intracellular Na+ accumulation, and a consequent increase in Ca2+ transient amplitude through reverse Na+/Ca2+ exchange. However, clinical evidence assigns a detrimental role to MR activation in the pathogenesis of severe cardiac diseases such as congestive heart failure. This mini review is meant to present and briefly discuss some recent discoveries about locally triggered cardiac MR signals with the objective of shedding some light on its physiological but potentially pathological consequences in the heart.
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Affiliation(s)
- Irene Lucía Ennis
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", Facultad de Ciencias Médicas de la Plata, Universidad Nacional de La Plata, La Plata, Argentina
| | - Néstor Gustavo Pérez
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", Facultad de Ciencias Médicas de la Plata, Universidad Nacional de La Plata, La Plata, Argentina
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Escudero DS, Brea MS, Caldiz CI, Amarillo ME, Aranda JO, Portiansky EL, Pérez NG, Díaz RG. PDE5 inhibition improves cardiac morphology and function in SHR by reducing NHE1 activity: Repurposing Sildenafil for the treatment of hypertensive cardiac hypertrophy. Eur J Pharmacol 2021; 891:173724. [PMID: 33152335 DOI: 10.1016/j.ejphar.2020.173724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 10/30/2020] [Accepted: 11/01/2020] [Indexed: 01/16/2023]
Abstract
Previously, we have shown that an increased cGMP-activated protein Kinase (PKG) activity after phosphodiesterase 5 (PDE5) inhibition by Sildenafil (SIL), leads to myocardial Na+/H+ exchanger (NHE1) inhibition preserving its basal homeostatic function. Since NHE1 is hyperactive in the hypertrophied myocardium of spontaneous hypertensive rats (SHR), while its inhibition was shown to prevent and revert this pathology, the current study was aimed to evaluate the potential antihypertrophic effect of SIL on adult SHR myocardium. We initially tested the inhibitory capability of SIL on NHE1 in isolated cardiomyocytes of SHR by comparing H+ efflux during the recovery from an acid load. After confirmed that effect, eight-month-old SHR were chronically treated for one month with SIL through drinking water. Compared to their littermate controls, SIL-treated rats presented a decreased NHE1 activity, which correlated with a reduction in its phosphorylation level assigned to activation of a PKG-p38 MAP kinase-PP2A signaling pathway. Moreover, treated animals showed a decreased oxidative stress that appears to be a consequence of a decreased mitochondrial NHE1 phosphorylation. Treated SHR showed a significant reduction in the pro-hypertrophic phosphatase calcineurin, despite slight tendency to decrease hypertrophy was detected. When SIL treatment was prolonged to three months, a significant decrease in myocardial hypertrophy and interstitial fibrosis that correlated with a lower myocardial stiffness was observed. In conclusion, the current study provides evidence concerning the ability of SIL to revert established cardiac hypertrophy in SHR, a clinically relevant animal model that resembles human essential hypertension.
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Affiliation(s)
- Daiana S Escudero
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120, 1900 La Plata, Argentina
| | - María S Brea
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120, 1900 La Plata, Argentina
| | - Claudia I Caldiz
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120, 1900 La Plata, Argentina
| | - María E Amarillo
- Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Argentina
| | - Jorge O Aranda
- Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Argentina
| | - Enrique L Portiansky
- Laboratorio de Análisis de Imágenes, Facultad de Ciencias Veterinarias, Universidad Nacional de La Plata, Argentina
| | - Néstor G Pérez
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120, 1900 La Plata, Argentina
| | - Romina G Díaz
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E. Cingolani", Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120, 1900 La Plata, Argentina.
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Lorenzo-Almorós A, Cepeda-Rodrigo JM, Lorenzo Ó. Diabetic cardiomyopathy. Rev Clin Esp 2020; 222:S0014-2565(20)30025-4. [PMID: 32107015 DOI: 10.1016/j.rce.2019.10.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 10/13/2019] [Accepted: 10/21/2019] [Indexed: 01/09/2023]
Abstract
The relationship between diabetes and heart failure is complex and bidirectional. Nevertheless, the existence of a cardiomyopathy attributable exclusively to diabetes has been and is still the subject of controversy, due, among other reasons, to a lack of a consensus definition. There is also no unanimous agreement in terms of the physiopathogenic findings that need to be present in the definition of diabetic cardiomyopathy or on its classification, which, added to the lack of diagnostic methods and treatments specific for this disease, limits its general understanding. Studies conducted on diabetic cardiomyopathy, however, suggest a unique physiopathogenesis different from that of other diseases. Similarly, new treatments have been shown to play a potential role in this disease. The following review provides an update on diabetic cardiomyopathy.
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Affiliation(s)
- A Lorenzo-Almorós
- Servicio de Medicina Interna, Fundación Jiménez Díaz. Madrid, España.
| | - J M Cepeda-Rodrigo
- Servicio de Medicina Interna, Hospital Vega Baja, Orihuela, Alicante, España
| | - Ó Lorenzo
- Laboratorio de Renal, Vascular y Diabetes, IIS Fundación Jiménez-Díaz, Universidad Autónoma de Madrid, Madrid, España
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Yeves AM, Ennis IL. Na +/H + exchanger and cardiac hypertrophy. HIPERTENSION Y RIESGO VASCULAR 2019; 37:22-32. [PMID: 31601481 DOI: 10.1016/j.hipert.2019.09.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 08/16/2019] [Accepted: 09/03/2019] [Indexed: 12/31/2022]
Abstract
Reactive cardiac hypertrophy (CH) is an increase in heart mass in response to hemodynamic overload. Exercise-induced CH emerges as an adaptive response with improved cardiac function, in contrast to pathological CH that represents a risk factor for cardiovascular health. The Na+/H+ exchanger (NHE-1) is a membrane transporter that not only regulates intracellular pH but also intracellular Na+ concentration. In the scenario of cardiovascular diseases, myocardial NHE-1 is activated by a variety of stimuli, such as neurohumoral factors and mechanical stress, leading to intracellular Na+ overload and activation of prohypertrophic cascades. NHE-1 hyperactivity is intimately linked to heart diseases, including ischemia-reperfusion injury, maladaptive CH and heart failure. In this review, we will present evidence to support that the NHE-1 hyperactivity constitutes a "switch on/off" for the pathological phenotype during CH development. We will also discuss some classical and novel strategies to avoid NHE-1 hyperactivity, and that are therefore worthwhile to improve cardiovascular health.
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Affiliation(s)
- A M Yeves
- Centro de Investigaciones Cardiovasculares "Horacio E. Cingolani", Facultad de Ciencias Médicas, Universidad Nacional de La Plata - CONICET, Calle 60 y 120, 1900 La Plata, Argentina
| | - I L Ennis
- Centro de Investigaciones Cardiovasculares "Horacio E. Cingolani", Facultad de Ciencias Médicas, Universidad Nacional de La Plata - CONICET, Calle 60 y 120, 1900 La Plata, Argentina.
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Structural and Functional Changes in the Na +/H + Exchanger Isoform 1, Induced by Erk1/2 Phosphorylation. Int J Mol Sci 2019; 20:ijms20102378. [PMID: 31091671 PMCID: PMC6566726 DOI: 10.3390/ijms20102378] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 05/08/2019] [Accepted: 05/09/2019] [Indexed: 12/15/2022] Open
Abstract
The human Na+/H+ exchanger isoform 1 (NHE1) is a plasma membrane transport protein that plays an important role in pH regulation in mammalian cells. Because of the generation of protons by intermediary metabolism as well as the negative membrane potential, protons accumulate within the cytosol. Extracellular signal-regulated kinase (ERK)-mediated regulation of NHE1 is important in several human pathologies including in the myocardium in heart disease, as well as in breast cancer as a trigger for growth and metastasis. NHE1 has a N-terminal, a 500 amino acid membrane domain, and a C-terminal 315 amino acid cytosolic domain. The C-terminal domain regulates the membrane domain and its effects on transport are modified by protein binding and phosphorylation. Here, we discuss the physiological regulation of NHE1 by ERK, with an emphasis on the critical effects on structure and function. ERK binds directly to the cytosolic domain at specific binding domains. ERK also phosphorylates NHE1 directly at multiple sites, which enhance NHE1 activity with subsequent downstream physiological effects. The NHE1 cytosolic regulatory tail possesses both ordered and disordered regions, and the disordered regions are stabilized by ERK-mediated phosphorylation at a phosphorylation motif. Overall, ERK pathway mediated phosphorylation modulates the NHE1 tail, and affects the activity, structure, and function of this membrane protein.
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12
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Kim JC, Son MJ, Woo SH. Regulation of cardiac calcium by mechanotransduction: Role of mitochondria. Arch Biochem Biophys 2018; 659:33-41. [DOI: 10.1016/j.abb.2018.09.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 09/28/2018] [Indexed: 12/27/2022]
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13
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Wong KY, McKay R, Liu Y, Towle K, Elloumi Y, Li X, Quan S, Dutta D, Sykes BD, Fliegel L. Diverse residues of intracellular loop 5 of the Na +/H + exchanger modulate proton sensing, expression, activity and targeting. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1861:191-200. [PMID: 30071192 DOI: 10.1016/j.bbamem.2018.07.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 07/26/2018] [Accepted: 07/27/2018] [Indexed: 10/28/2022]
Abstract
The mammalian Na+/H+ exchanger isoform 1 (NHE1) is an integral membrane protein that regulates intracellular pH (pHi) by removing a single intracellular proton in exchange for one extracellular sodium ion. It is involved in cardiac hypertrophy and ischemia reperfusion damage to the heart and elevation of its activity is a trigger for breast cancer metastasis. NHE1 has an extensive 500 amino acid N-terminal membrane domain that mediates transport and consists of 12 transmembrane segments connected by intracellular and extracellular loops. Intracellular loops are hypothesized to modulate the sensitivity to pHi. In this study, we characterized the structure and function of intracellular loop 5 (IL5), specifically amino acids 431-443. Mutation of eleven residues to alanine caused partial or nearly complete inhibition of transport; notably, mutation of residues L432, T433, I436, N437, R440 and K443 demonstrated these residues had critical roles in NHE1 function independent of effects on targeting or expression. The nuclear magnetic resonance (NMR) solution spectra of the IL5 peptide in a membrane mimetic sodium dodecyl sulfate solution revealed that IL5 has a stable three-dimensional structure with substantial alpha helical character. NMR chemical shifts indicated that K438 was in close proximity with W434. Overall, our results show that IL5 is a critical, intracellular loop with a propensity to form an alpha helix, and many residues of this intracellular loop are critical to proton sensing and ion transport.
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Affiliation(s)
- Ka Yee Wong
- Dept of Biochemistry, University of Alberta, Canada
| | - Ryan McKay
- Dept of Chemistry, University of Alberta, Canada.
| | | | | | | | - Xiuju Li
- Dept of Biochemistry, University of Alberta, Canada
| | - Sicheng Quan
- Dept of Biochemistry, University of Alberta, Canada
| | | | | | - Larry Fliegel
- Dept of Biochemistry, University of Alberta, Canada.
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Xue J, Zhou D, Poulsen O, Hartley I, Imamura T, Xie EX, Haddad GG. Exploring miRNA-mRNA regulatory network in cardiac pathology in Na +/H + exchanger isoform 1 transgenic mice. Physiol Genomics 2018; 50:846-861. [PMID: 30029588 DOI: 10.1152/physiolgenomics.00048.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Numerous studies have demonstrated that Na+/H+ exchanger isoform 1 (NHE1) is elevated in myocardial diseases and its effect is detrimental. To better understand the involvement of NHE1, we have previously studied cardiac-specific NHE1 transgenic mice and shown that these mice develop cardiac hypertrophy, interstitial fibrosis, and cardiac dysfunction. The purpose of current study was to identify microRNAs and their mRNA targets involved in NHE1-mediated cardiac injury. An unbiased high-throughput sequencing study was performed on both microRNAs and mRNAs. RNA sequencing showed that differentially expressed genes were enriched in hypertrophic cardiomyopathy pathway by Kyoto Encyclopedia of Genes and Genomes annotation in NHE1 transgenic hearts. These genes were classified as contraction defects (e.g., Myl2, Myh6, Mybpc3, and Actb), impaired intracellular Ca2+ homeostasis (e.g., SERCA2a, Ryr2, Rcan1, and CaMKII delta), and signaling molecules for hypertrophic cardiomyopathy (e.g., Itga/b, IGF-1, Tgfb2/3, and Prkaa1/2). microRNA sequencing revealed that 15 microRNAs were differentially expressed (2-fold, P < 0.05). Six of them (miR-1, miR-208a-3p, miR-199a-5p, miR-21-5p, miR-146a-5p, and miR-30c-5p) were reported to be related to cardiac pathological functions. The integrative analysis of microRNA and RNA sequencing data identified several crucial microRNAs including miR-30c-5p, miR-199a-5p, miR-21-5p, and miR-34a-5p as well as 10 of their mRNA targets that may affect the heart via NFAT hypertrophy and cardiac hypertrophy signaling. Furthermore, important microRNAs and mRNA targets were validated by quantitative PCR. Our study comprehensively characterizes the expression patterns of microRNAs and mRNAs, establishes functional microRNA-mRNA pairs, elucidates the potential signaling pathways, and provides novel insights on the mechanisms underlying NHE1-medicated cardiac injury.
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Affiliation(s)
- Jin Xue
- Department of Pediatrics, University of California San Diego , La Jolla, California
| | - Dan Zhou
- Department of Pediatrics, University of California San Diego , La Jolla, California
| | - Orit Poulsen
- Department of Pediatrics, University of California San Diego , La Jolla, California
| | - Iain Hartley
- Department of Pediatrics, University of California San Diego , La Jolla, California
| | - Toshihiro Imamura
- Department of Pediatrics, University of California San Diego , La Jolla, California
| | - Edward X Xie
- Department of Pediatrics, University of California San Diego , La Jolla, California
| | - Gabriel G Haddad
- Department of Pediatrics, University of California San Diego , La Jolla, California.,Departments of Neurosciences, University of California San Diego , La Jolla, California.,The Rady Children's Hospital , San Diego, California
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15
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Long non-coding RNA CHRF facilitates cardiac hypertrophy through regulating Akt3 via miR-93. Cardiovasc Pathol 2018; 35:29-36. [DOI: 10.1016/j.carpath.2018.04.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 03/09/2018] [Accepted: 04/09/2018] [Indexed: 12/21/2022] Open
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16
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Packer M. Activation and Inhibition of Sodium-Hydrogen Exchanger Is a Mechanism That Links the Pathophysiology and Treatment of Diabetes Mellitus With That of Heart Failure. Circulation 2017; 136:1548-1559. [PMID: 29038209 DOI: 10.1161/circulationaha.117.030418] [Citation(s) in RCA: 151] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The mechanisms underlying the progression of diabetes mellitus and heart failure are closely intertwined, such that worsening of one condition is frequently accompanied by worsening of the other; the degree of clinical acceleration is marked when the 2 coexist. Activation of the sodium-hydrogen exchanger in the heart and vasculature (NHE1 isoform) and the kidneys (NHE3 isoform) may serve as a common mechanism that links both disorders and may underlie their interplay. Insulin insensitivity and adipokine abnormalities (the hallmarks of type 2 diabetes mellitus) are characteristic features of heart failure; conversely, neurohormonal systems activated in heart failure (norepinephrine, angiotensin II, aldosterone, and neprilysin) impair insulin sensitivity and contribute to microvascular disease in diabetes mellitus. Each of these neurohormonal derangements may act through increased activity of both NHE1 and NHE3. Drugs used to treat diabetes mellitus may favorably affect the pathophysiological mechanisms of heart failure by inhibiting either or both NHE isoforms, and drugs used to treat heart failure may have beneficial effects on glucose tolerance and the complications of diabetes mellitus by interfering with the actions of NHE1 and NHE3. The efficacy of NHE inhibitors on the risk of cardiovascular events may be enhanced when heart failure and glucose intolerance coexist and may be attenuated when drugs with NHE inhibitory actions are given concomitantly. Therefore, the sodium-hydrogen exchanger may play a central role in the interplay of diabetes mellitus and heart failure, contribute to the physiological and clinical progression of both diseases, and explain certain drug-drug and drug-disease interactions that have been reported in large-scale randomized clinical trials.
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Affiliation(s)
- Milton Packer
- From Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, TX.
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17
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Bkaily G, Jacques D. Na +-H + exchanger and proton channel in heart failure associated with Becker and Duchenne muscular dystrophies. Can J Physiol Pharmacol 2017; 95:1213-1223. [PMID: 28727929 DOI: 10.1139/cjpp-2017-0265] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Cardiomyopathy is found in patients with Duchenne (DMD) and Becker (BMD) muscular dystrophies, which are linked muscle diseases caused by mutations in the dystrophin gene. Dystrophin defects are not limited to DMD but are also present in mild BMD. The hereditary cardiomyopathic hamster of the UM-X7.1 strain is a particular experimental model of heart failure (HF) leading to early death in muscular dystrophy (dystrophin deficiency and sarcoglycan mutation) and heart disease (δ-sarcoglycan deficiency and dystrophin mutation) in human DMD. Using this model, our previous work showed a defect in intracellular sodium homeostasis before the appearance of any apparent biochemical and histological defects. This was attributed to the continual presence of the fetal slow sodium channel, which was also found to be active in human DMD. Due to muscular intracellular acidosis, the intracellular sodium overload in DMD and BMD was also due to sodium influx through the sodium-hydrogen exchanger NHE-1. Lifetime treatment with an NHE-1 inhibitor prevented intracellular Na+ overload and early death due to HF. Our previous work also showed that another proton transporter, the voltage-gated proton channel (Hv1), exists in many cell types including heart cells and skeletal muscle fibers. The Hv1 could be indirectly implicated in the beneficial effect of blocking NHE-1.
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Affiliation(s)
- Ghassan Bkaily
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.,Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
| | - Danielle Jacques
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.,Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada
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18
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GPER is involved in the stimulatory effects of aldosterone in breast cancer cells and breast tumor-derived endothelial cells. Oncotarget 2016; 7:94-111. [PMID: 26646587 PMCID: PMC4807985 DOI: 10.18632/oncotarget.6475] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/22/2015] [Indexed: 12/16/2022] Open
Abstract
Aldosterone induces relevant effects binding to the mineralcorticoid receptor (MR), which acts as a ligand-gated transcription factor. Alternate mechanisms can mediate the action of aldosterone such as the activation of epidermal growth factor receptor (EGFR), MAPK/ERK, transcription factors and ion channels. The G-protein estrogen receptor (GPER) has been involved in the stimulatory effects of estrogenic signalling in breast cancer. GPER has been also shown to contribute to certain responses to aldosterone, however the role played by GPER and the molecular mechanisms implicated remain to be fully understood. Here, we evaluated the involvement of GPER in the stimulatory action exerted by aldosterone in breast cancer cells and breast tumor derived endothelial cells (B-TEC). Competition assays, gene expression and silencing studies, immunoblotting and immunofluorescence experiments, cell proliferation and migration were performed in order to provide novel insights into the role of GPER in the aldosterone-activated signalling. Our results demonstrate that aldosterone triggers the EGFR/ERK transduction pathway in a MR- and GPER-dependent manner. Aldosterone does not bind to GPER, it however induces the direct interaction between MR and GPER as well as between GPER and EGFR. Next, we ascertain that the up-regulation of the Na+/H+ exchanger-1 (NHE-1) induced by aldosterone involves MR and GPER. Biologically, both MR and GPER contribute to the proliferation and migration of breast and endothelial cancer cells mediated by NHE-1 upon aldosterone exposure. Our data further extend the current knowledge on the molecular mechanisms through which GPER may contribute to the stimulatory action elicited by aldosterone in breast cancer.
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19
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Bkaily G, Chahine M, Al-Khoury J, Avedanian L, Beier N, Scholz W, Jacques D. Na+–H+ exchanger inhibitor prevents early death in hereditary cardiomyopathy. Can J Physiol Pharmacol 2015; 93:923-34. [DOI: 10.1139/cjpp-2015-0107] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Using the UM-X7.1 hereditary cardiomyopathic and muscular dystrophy hamsters (HCMH), we tested the effects of lifelong preventive or curative treatments during the heart failure phase with the NHE-1 inhibitor EMD 87580 (EMD) or with the angiotensin-converting enzyme inhibitor cilazapril on the intracellular Na+ and Ca2+ overloads, elevated level of NHE-1, necrosis, hypertrophy, heart failure, and early death. Our results showed that 310-day pretreatment of 30-day-old HCMHs with EMD significantly prevented cardiac necrosis, cardiomyocyte hypertrophy, and reduced the heart to body mass ratio. This treatment significantly prevented Na+ and Ca2+ overloads and the increase in NHE-1 protein level observed in HCMHs. Importantly, this lifelong preventive treatment significantly decreased the levels of creatine kinase and prevented early death of HCMHs. Curative treatment of hypertrophic 275-day-old HCMHs for 85 days with EMD significantly prevented hypertrophy and early death of HCMHs. However, treatments with cilazapril did not have any significant effects on the cardiac parameters studied or on early death of HCMHs. Our results suggest that the increase in the NHE-1 level and the consequent Na+ and Ca2+ overloads are implicated in the pathological process leading to heart failure and early death in HCMHs, and treatment with the NHE-1 inhibitor is promising for preventing early death in hereditary cardiomyopathy.
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Affiliation(s)
- Ghassan Bkaily
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Mirna Chahine
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Johny Al-Khoury
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Levon Avedanian
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
| | - Norbert Beier
- Diabetes and Complication Research, Merck KGaA, D-64293 Darmstadt, Germany
| | - Wolfgang Scholz
- Diabetes and Complication Research, Merck KGaA, D-64293 Darmstadt, Germany
| | - Danielle Jacques
- Department of Anatomy and Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001 12th Avenue North, Sherbrooke, QC J1H 5N4, Canada
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20
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Wang Y, Li ZC, Zhang P, Poon E, Kong CW, Boheler KR, Huang Y, Li RA, Yao X. Nitric Oxide-cGMP-PKG Pathway Acts on Orai1 to Inhibit the Hypertrophy of Human Embryonic Stem Cell-Derived Cardiomyocytes. Stem Cells 2015; 33:2973-84. [PMID: 26269433 DOI: 10.1002/stem.2118] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Accepted: 07/15/2015] [Indexed: 11/08/2022]
Abstract
Cardiac hypertrophy is an abnormal enlargement of heart muscle. It frequently results in congestive heart failure, which is a leading cause of human death. Previous studies demonstrated that the nitric oxide (NO), cyclic GMP (cGMP), and protein kinase G (PKG) signaling pathway can inhibit cardiac hypertrophy and thus improve cardiac function. However, the underlying mechanisms are not fully understood. Here, based on the human embryonic stem cell-derived cardiomyocyte (hESC-CM) model system, we showed that Orai1, the pore-forming subunit of store-operated Ca(2+) entry (SOCE), is the downstream effector of PKG. Treatment of hESC-CMs with an α-adrenoceptor agonist phenylephrine (PE) caused a marked hypertrophy, which was accompanied by an upregulation of Orai1. Moreover, suppression of Orai1 expression/activity using Orai1-siRNAs or a dominant-negative construct Orai1(G98A) inhibited the hypertrophy, suggesting that Orai1-mediated SOCE is indispensable for the PE-induced hypertrophy of hESC-CMs. In addition, the hypertrophy was inhibited by NO and cGMP via activating PKG. Importantly, substitution of Ala for Ser(34) in Orai1 abolished the antihypertrophic effects of NO, cGMP, and PKG. Furthermore, PKG could directly phosphorylate Orai1 at Ser(34) and thus prevent Orai1-mediated SOCE. Together, we conclude that NO, cGMP, and PKG inhibit the hypertrophy of hESC-CMs via PKG-mediated phosphorylation on Orai1-Ser-34. These results provide novel mechanistic insights into the action of cGMP-PKG-related antihypertrophic agents, such as NO donors and sildenafil.
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Affiliation(s)
- Y Wang
- Li Ka Shing Institute of Health Sciences and School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, People's Republic of China.,Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China.,Department of Hematology, The 3rd Xiangya Hospital, Central South University, Changsha, People's Republic of China
| | - Z C Li
- Li Ka Shing Institute of Health Sciences and School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, People's Republic of China.,Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China
| | - P Zhang
- Li Ka Shing Institute of Health Sciences and School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, People's Republic of China.,Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China
| | - E Poon
- Stem Cell and Regenerative Medicine Consortium, The University of Hong Kong, Hong Kong, People's Republic of China.,The Department of Physiology, The University of Hong Kong, Hong Kong, People's Republic of China
| | - C W Kong
- Stem Cell and Regenerative Medicine Consortium, The University of Hong Kong, Hong Kong, People's Republic of China
| | - K R Boheler
- Stem Cell and Regenerative Medicine Consortium, The University of Hong Kong, Hong Kong, People's Republic of China.,The Department of Physiology, The University of Hong Kong, Hong Kong, People's Republic of China
| | - Y Huang
- Li Ka Shing Institute of Health Sciences and School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - R A Li
- Stem Cell and Regenerative Medicine Consortium, The University of Hong Kong, Hong Kong, People's Republic of China
| | - X Yao
- Li Ka Shing Institute of Health Sciences and School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Hong Kong, People's Republic of China.,Shenzhen Research Institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China
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21
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Odunewu-Aderibigbe A, Fliegel L. The Na+/H+exchanger and pH regulation in the heart. IUBMB Life 2014; 66:679-85. [DOI: 10.1002/iub.1323] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 10/15/2014] [Indexed: 11/11/2022]
Affiliation(s)
| | - Larry Fliegel
- Department of Biochemistry; University of Alberta; Edmonton AB Canada
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22
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Yoshino T, Nagoshi T, Anzawa R, Kashiwagi Y, Ito K, Katoh D, Fujisaki M, Kayama Y, Date T, Hongo K, Yoshimura M. Preconditioning actions of aldosterone through p38 signaling modulation in isolated rat hearts. J Endocrinol 2014; 222:289-99. [PMID: 24895416 DOI: 10.1530/joe-14-0067] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Although persistent excessive actions of aldosterone have unfavorable effects on the cardiovascular system, primarily via mineralocorticoid receptor (MR)-dependent pathways, the pathophysiological significance of aldosterone cascade activation in heart diseases has not yet been fully clarified. We herein examined the effects of short-term aldosterone stimulation at a physiological dose on cardiac function during ischemia-reperfusion injury (IRI). In order to study the effects of aldosterone preconditioning, male Wistar rat Langendorff hearts were perfused with 10(-9) mol/l of aldosterone for 10 min before ischemia, and the response to IRI was assessed. Although aldosterone did not affect the baseline hemodynamic parameters, preconditioning actions of aldosterone significantly improved the recovery in left ventricular contractility and left ventricular end-diastolic pressure associated with a reduced activity of creatine phosphokinase released into the perfusate after ischemia-reperfusion. Notably, the MR inhibitor eplerenone did not abrogate these beneficial effects. Biochemical analyses revealed that p38MAPK phosphorylation was significantly increased during aldosterone preconditioning before ischemia, whereas its phosphorylation was substantially attenuated during sustained ischemia-reperfusion, compared with the results for in the non-preconditioned control hearts. This dual regulation of p38MAPK was not affected by eplerenone. The phosphorylation levels of other MAPKs were not altered by aldosterone preconditioning. In conclusion, the temporal induction of the aldosterone cascade, at a physiological dose, has favorable effects on cardiac functional recovery and injury following ischemia-reperfusion in a MR-independent manner. Phasic dynamism of p38MAPK activation may play a key role in the physiological compensatory pathway of aldosterone under severe cardiac pathological conditions.
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Affiliation(s)
- Takuya Yoshino
- Division of CardiologyDepartment of Internal Medicine, The Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Tomohisa Nagoshi
- Division of CardiologyDepartment of Internal Medicine, The Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Ryuko Anzawa
- Division of CardiologyDepartment of Internal Medicine, The Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Yusuke Kashiwagi
- Division of CardiologyDepartment of Internal Medicine, The Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Keiichi Ito
- Division of CardiologyDepartment of Internal Medicine, The Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Daisuke Katoh
- Division of CardiologyDepartment of Internal Medicine, The Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Masami Fujisaki
- Division of CardiologyDepartment of Internal Medicine, The Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Yosuke Kayama
- Division of CardiologyDepartment of Internal Medicine, The Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Taro Date
- Division of CardiologyDepartment of Internal Medicine, The Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Kenichi Hongo
- Division of CardiologyDepartment of Internal Medicine, The Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan
| | - Michihiro Yoshimura
- Division of CardiologyDepartment of Internal Medicine, The Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan
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23
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Alves C, Lee BL, Sykes BD, Fliegel L. Structural and Functional Analysis of the Transmembrane Segment Pair VI and VII of the NHE1 Isoform of the Na+/H+ Exchanger. Biochemistry 2014; 53:3658-70. [DOI: 10.1021/bi500392y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Claudia Alves
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
| | - Brian L. Lee
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
| | - Brian D. Sykes
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
| | - Larry Fliegel
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
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24
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Ennis IL, Aiello EA, Cingolani HE, Perez NG. The autocrine/paracrine loop after myocardial stretch: mineralocorticoid receptor activation. Curr Cardiol Rev 2014; 9:230-40. [PMID: 23909633 PMCID: PMC3780348 DOI: 10.2174/1573403x113099990034] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 12/13/2012] [Indexed: 01/13/2023] Open
Abstract
The stretch of cardiac muscle increases developed force in two phases. The first phase, which occurs rapidly, constitutes the well-known Frank-Starling mechanism and it is generally attributed to enhanced myofilament responsiveness to Ca(2+). The second phase or slow force response (SFR) occurs gradually and is due to an increase in the calcium transient amplitude as a result of a stretch-triggered autocrine/paracrine mechanism. We previously showed that Ca(2+) entry through reverse Na(+)/Ca(2+) exchange underlies the SFR, as the final step of an autocrine/paracrine cascade involving release of angiotensin II/endothelin, and a Na(+)/H(+) exchanger (NHE-1) activation-mediated rise in Na+. In the present review we mainly focus on our three latest contributions to the understanding of this signalling pathway triggered by myocardial stretch: 1) The finding that an increased production of reactive oxygen species (ROS) from mitochondrial origin is critical in the activation of the NHE-1 and therefore in the genesis of the SFR; 2) the demonstration of a key role played by the transactivation of the epidermal growth factor receptor; and 3) the involvement of mineralocorticoid receptors (MR) activation in the stretch-triggered cascade leading to the SFR. Among these novel contributions, the critical role played by the MR is perhaps the most important one. This finding may conceivably provide a mechanistic explanation to the recently discovered strikingly beneficial effects of MR antagonism in humans with cardiac hypertrophy and failure.
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Affiliation(s)
- Irene L Ennis
- Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Medicas, Universidad Nacional de La Plata, Argentina
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25
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Katoh D, Hongo K, Ito K, Yoshino T, Kayama Y, Kawai M, Date T, Yoshimura M. Corticosteroids increase intracellular free sodium ion concentration via glucocorticoid receptor pathway in cultured neonatal rat cardiomyocytes. INTERNATIONAL JOURNAL OF CARDIOLOGY. HEART & VESSELS 2014; 3:49-56. [PMID: 29450170 PMCID: PMC5801272 DOI: 10.1016/j.ijchv.2014.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 03/03/2014] [Indexed: 11/27/2022]
Abstract
Background Glucocorticoids as well as mineralocorticoid have been shown to play essential roles in the regulation of electrical and mechanical activities in cardiomyocytes. Excess of these hormones is an independent risk factor for cardiovascular disease. Intracellular sodium ([Na+]i) kinetics are involved in cardiac diseases, including ischemia, heart failure and hypertrophy. However, intrinsic mediators that regulate [Na+]i in cardiomyocytes have not been widely discussed. Moreover, the quantitative estimation of altered [Na+]i in cultured cardiomyocytes and the association between the level of [Na+]i and the severity of pathological conditions, such as hypertrophy, have not been precisely reported. Methods and results We herein demonstrate the quantitative estimation of [Na+]i in cultured neonatal rat cardiomyocytes following 24 h of treatment with corticosterone, aldosterone and dexamethasone. The physiological concentration of glucocorticoids increased [Na+]i up to approximately 2.5 mM (an almost 1.5-fold increase compared to the control) in a dose-dependent manner; this effect was blocked by a glucocorticoid receptor (GR) antagonist but not a mineralocorticoid receptor antagonist. Furthermore, glucocorticoids induced cardiac hypertrophy, and the hypertrophic gene expression was positively and significantly correlated with the level of [Na+]i. Dexamethasone induced the upregulation of Na+/Ca2 + exchanger 1 at the mRNA and protein levels. Conclusions The physiological concentration of glucocorticoids increases [Na+]i via GR. The dexamethasone-induced upregulation of NCX1 is partly involved in the glucocorticoid-induced alteration of [Na+]i in cardiomyocytes. These results provide new insight into the mechanisms by which glucocorticoid excess within a physiological concentration contributes to the development of cardiac pathology.
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Affiliation(s)
- Daisuke Katoh
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Kenichi Hongo
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Keiichi Ito
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Takuya Yoshino
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Yosuke Kayama
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Makoto Kawai
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Taro Date
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo 105-8461, Japan
| | - Michihiro Yoshimura
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo 105-8461, Japan
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26
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De Giusti VC, Ciancio MC, Orlowski A, Aiello EA. Modulation of the cardiac sodium/bicarbonate cotransporter by the renin angiotensin aldosterone system: pathophysiological consequences. Front Physiol 2014; 4:411. [PMID: 24478712 PMCID: PMC3894460 DOI: 10.3389/fphys.2013.00411] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 12/27/2013] [Indexed: 12/22/2022] Open
Abstract
The sodium/bicarbonate cotransporter (NBC) is one of the major alkalinizing mechanisms in the cardiomyocytes. It has been demonstrated the existence of at least two functional isoforms, one that promotes the co-influx of 1 molecule of Na+ per 1 molecule of HCO−3 (electroneutral isoform; NBCn1) and the other one that generates the co-influx of 1 molecule of Na+ per 2 molecules of HCO−3 (electrogenic isoform; NBCe1). Both isoforms are important to maintain intracellular pH (pHi) and sodium concentration ([Na+]i). In addition, NBCe1 generates an anionic repolarizing current that modulates the action potential duration (APD). The renin-angiotensin-aldosterone system (RAAS) is implicated in the modulation of almost all physiological cardiac functions and is also involved in the development and progression of cardiac diseases. It was reported that angiotensin II (Ang II) exhibits an opposite effect on NBC isoforms: it activates NBCn1 and inhibits NBCe1. The activation of NBCn1 leads to an increase in pHi and [Na+]i, which indirectly, due to the stimulation of reverse mode of the Na+/Ca2+ exchanger (NCX), conduces to an increase in the intracellular Ca2+ concentration. On the other hand, the inhibition of NBCe1 generates an APD prolongation, potentially representing a risk of arrhythmias. In the last years, the potentially altered NBC function in pathological scenarios, as cardiac hypertrophy and ischemia-reperfusion, has raised increasing interest among investigators. This review attempts to draw the attention on the relevant regulation of NBC activity by RAAS, since it modulates pHi and [Na+]i, which are involved in the development of cardiac hypertrophy, the damage produced by ischemia-reperfusion and the generation of arrhythmic events, suggesting a potential role of NBC in cardiac diseases.
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Affiliation(s)
- Verónica C De Giusti
- Facultad de Ciencias Médicas, Centro de Investigaciones Cardiovasculares, Universidad Nacional de La Plata, CONICET-La Plata La Plata, Argentina
| | - María C Ciancio
- Facultad de Ciencias Médicas, Centro de Investigaciones Cardiovasculares, Universidad Nacional de La Plata, CONICET-La Plata La Plata, Argentina
| | - Alejandro Orlowski
- Facultad de Ciencias Médicas, Centro de Investigaciones Cardiovasculares, Universidad Nacional de La Plata, CONICET-La Plata La Plata, Argentina
| | - Ernesto A Aiello
- Facultad de Ciencias Médicas, Centro de Investigaciones Cardiovasculares, Universidad Nacional de La Plata, CONICET-La Plata La Plata, Argentina
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Katoh D, Hongo K, Ito K, Yoshino T, Kayama Y, Komukai K, Kawai M, Date T, Yoshimura M. A technique for quantifying intracellular free sodium ion using a microplate reader in combination with sodium-binding benzofuran isophthalate and probenecid in cultured neonatal rat cardiomyocytes. BMC Res Notes 2013; 6:556. [PMID: 24369990 PMCID: PMC3879185 DOI: 10.1186/1756-0500-6-556] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 12/18/2013] [Indexed: 11/16/2022] Open
Abstract
Background Intracellular sodium ([Na+]i) kinetics are involved in cardiac diseases including ischemia, heart failure, and hypertrophy. Because [Na+]i plays a crucial role in modulating the electrical and contractile activity in the heart, quantifying [Na+]i is of great interest. Using fluorescent microscopy with sodium-binding benzofuran isophthalate (SBFI) is the most commonly used method for measuring [Na+]i. However, one limitation associated with this technique is that the test cannot simultaneously evaluate the effects of several types or various concentrations of compounds on [Na+]i. Moreover, there are few reports on the long-term effects of compounds on [Na+]i in cultured cells, although rapid changes in [Na+]i during a period of seconds or several minutes have been widely discussed. Findings We established a novel technique for quantifying [Na+]i in cultured neonatal rat cardiomyocytes attached to a 96-well plate using a microplate reader in combination with SBFI and probenecid. We showed that probenecid is indispensable for the accurate measurement because it prevents dye leakage from the cells. We further confirmed the reliability of this system by quantifying the effects of ouabain, which is known to transiently alter [Na+]i. To illustrate the utility of the new method, we also examined the chronic effects of aldosterone on [Na+]i in cultured cardiomyocytes. Conclusions Our technique can rapidly measure [Na+]i with accuracy and sensitivity comparable to the traditional microscopy based method. The results demonstrated that this 96-well plate based measurement has merits, especially for screening test of compounds regulating [Na+]i, and is useful to elucidate the mechanisms and consequences of altered [Na+]i handling in cardiomyocytes.
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Affiliation(s)
- Daisuke Katoh
- Division of Cardiology, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo 105-8461, Japan.
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28
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Li J, Xu L, Ye J, Li X, Zhang D, Liang D, Xu X, Qi M, Li C, Zhang H, Wang J, Liu Y, Zhang Y, Zhou Z, Liang X, Li J, Peng L, Zhu W, Chen YH. Aberrant dynamin 2-dependent Na(+) /H(+) exchanger-1 trafficking contributes to cardiomyocyte apoptosis. J Cell Mol Med 2013; 17:1119-27. [PMID: 23837875 PMCID: PMC4118171 DOI: 10.1111/jcmm.12086] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 05/13/2013] [Indexed: 02/05/2023] Open
Abstract
Sarcolemmal Na+/H+ exchanger 1 (NHE1) activity is essential for the intracellular pH (pHi) homeostasis in cardiac myocytes. Emerging evidence indicates that sarcolemmal NHE1 dysfunction was closely related to cardiomyocyte death, but it remains unclear whether defective trafficking of NHE1 plays a role in the vital cellular signalling processes. Dynamin (DNM), a large guanosine triphosphatase (GTPase), is best known for its roles in membrane trafficking events. Herein, using co-immunoprecipitation, cell surface biotinylation and confocal microscopy techniques, we investigated the potential regulation on cardiac NHE1 activity by DNM. We identified that DNM2, a cardiac isoform of DNM, directly binds to NHE1. Overexpression of a wild-type DNM2 or a dominant-negative DNM2 mutant with defective GTPase activity in adult rat ventricular myocytes (ARVMs) facilitated or retarded the internalization of sarcolemmal NHE1, whereby reducing or increasing its activity respectively. Importantly, the increased NHE1 activity associated with DNM2 deficiency led to ARVMs apoptosis, as demonstrated by cell viability, terminal deoxynucleotidyl transferase–mediated dUTP nick-end labelling assay, Bcl-1/Bax expression and caspase-3 activity, which were effectively rescued by pharmacological inhibition of NHE1 with zoniporide. Thus, our results demonstrate that disruption of the DNM2-dependent retrograde trafficking of NHE1 contributes to cardiomyocyte apoptosis.
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Affiliation(s)
- Jun Li
- Key Laboratory of Arrhythmias of the Ministry of Education of China, East Hospital, Tongji University School of Medicine, Shanghai, China; Institute of Medical Genetics, Tongji University, Shanghai, China
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29
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De Giusti VC, Caldiz CI, Ennis IL, Pérez NG, Cingolani HE, Aiello EA. Mitochondrial reactive oxygen species (ROS) as signaling molecules of intracellular pathways triggered by the cardiac renin-angiotensin II-aldosterone system (RAAS). Front Physiol 2013; 4:126. [PMID: 23755021 PMCID: PMC3667248 DOI: 10.3389/fphys.2013.00126] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 05/13/2013] [Indexed: 12/22/2022] Open
Abstract
Mitochondria represent major sources of basal reactive oxygen species (ROS) production of the cardiomyocyte. The role of ROS as signaling molecules that mediate different intracellular pathways has gained increasing interest among physiologists in the last years. In our lab, we have been studying the participation of mitochondrial ROS in the intracellular pathways triggered by the renin-angiotensin II-aldosterone system (RAAS) in the myocardium during the past few years. We have demonstrated that acute activation of cardiac RAAS induces mitochondrial ATP-dependent potassium channel (mitoKATP) opening with the consequent enhanced production of mitochondrial ROS. These oxidant molecules, in turn, activate membrane transporters, as sodium/hydrogen exchanger (NHE-1) and sodium/bicarbonate cotransporter (NBC) via the stimulation of the ROS-sensitive MAPK cascade. The stimulation of such effectors leads to an increase in cardiac contractility. In addition, it is feasible to suggest that a sustained enhanced production of mitochondrial ROS induced by chronic cardiac RAAS, and hence, chronic NHE-1 and NBC stimulation, would also result in the development of cardiac hypertrophy.
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Affiliation(s)
- V C De Giusti
- Facultad de Ciencias Médicas, Centro de Investigaciones Cardiovasculares, UNLP-CONICET La Plata, Argentina
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30
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Pandey KB, Jha R, Rizvi SI. Erythrocyte membrane transporters during human ageing: Modulatory role of tea catechins. Clin Exp Pharmacol Physiol 2013; 40:83-9. [DOI: 10.1111/1440-1681.12041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/12/2012] [Indexed: 12/16/2022]
Affiliation(s)
| | - Rashmi Jha
- Department of Biochemistry; University of Allahabad; Allahabad; India
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31
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Pelzl L, Pakladok T, Pathare G, Fakhri H, Michael D, Wagner CA, Paulmichl M, Lang F. DOCA sensitive pendrin expression in kidney, heart, lung and thyroid tissues. Cell Physiol Biochem 2012; 30:1491-501. [PMID: 23235354 DOI: 10.1159/000343337] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2012] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND/AIMS Pendrin (SLC26A4), a transporter accomplishing anion exchange, is expressed in inner ear, thyroid gland, kidneys, lung, liver and heart. Loss or reduction of function mutations of SLC26A4 underlie Pendred syndrome, a disorder invariably leading to hearing loss with enlarged vestibular aqueducts and in some patients to hypothyroidism and goiter. Renal pendrin expression is up-regulated by mineralocorticoids such as aldosterone or deoxycorticosterone (DOCA). Little is known about the impact of mineralocorticoids on pendrin expression in extrarenal tissues. METHODS The present study utilized RT-qPCR and Western blotting to quantify the transcript levels and protein abundance of Slc26a4 in murine kidney, thyroid, heart and lung prior to and following subcutaneous administration of 100 mg/kg DOCA. RESULTS Slc26a4 transcript levels as compared to Gapdh transcript levels were significantly increased by DOCA treatment in kidney, heart, lung and thyroid. Accordingly pendrin protein expression was again significantly increased by DOCA treatment in kidney, heart, lung and thyroid. CONCLUSION The observations reveal mineralocorticoid sensitivity of pendrin expression in kidney, heart, thyroid and lung.
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Affiliation(s)
- Lisann Pelzl
- Department of Physiology, University of Tuebingen, Tuebingen, Germany
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32
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Brown BF, Quon A, Dyck JRB, Casey JR. Carbonic anhydrase II promotes cardiomyocyte hypertrophy. Can J Physiol Pharmacol 2012; 90:1599-610. [PMID: 23210439 DOI: 10.1139/y2012-142] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Pathological cardiac hypertrophy, the maladaptive remodelling of the myocardium, often progresses to heart failure. The sodium-proton exchanger (NHE1) and chloride-bicarbonate exchanger (AE3) have been implicated as important in the hypertrophic cascade. Carbonic anhydrase II (CAII) provides substrates for these transporters (protons and bicarbonate, respectively). CAII physically interacts with NHE1 and AE3, enhancing their respective ion transport activities by increasing the concentration of substrate at their transport sites. Earlier studies found that a broad-spectrum carbonic anhydrase inhibitor prevented cardiomyocyte hypertrophy (CH), suggesting that carbonic anhydrase is important in the development of hypertrophy. Here we investigated whether cytosolic CAII was the CA isoform involved in hypertrophy. Neonatal rat ventricular myocytes (NRVMs) were transduced with recombinant adenoviral constructs to over-express wild-type or catalytically inactive CAII (CAII-V143Y). Over-expression of wild-type CAII in NRVMs did not affect CH development. In contrast, CAII-V143Y over-expression suppressed the response to hypertrophic stimuli, suggesting that CAII-V143Y behaves in a dominant negative fashion over endogenous CAII to suppress hypertrophy. We also examined CAII-deficient (Car2) mice, whose hearts exhibit physiological hypertrophy without any decrease in cardiac function. Moreover, cardiomyocytes from Car2 mice do not respond to prohypertrophic stimulation. Together, these findings support a role of CAII in promoting CH.
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Affiliation(s)
- Brittany F Brown
- Membrane Protein Disease Research Group, Department of Biochemistry, School of Translational Medicine, University of Alberta, Edmonton, AB, Canada
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33
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Galuppo P, Bauersachs J. Mineralocorticoid receptor activation in myocardial infarction and failure: recent advances. Eur J Clin Invest 2012; 42:1112-20. [PMID: 22536780 DOI: 10.1111/j.1365-2362.2012.02676.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The classical view of aldosterone actions via the mineralocorticoid receptor (MR) limited to control of fluid balance and blood pressure homoeostasis has been progressively overcome by clinical and experimental evidence emphasizing the pleiotropic role of MR activation in the pathogenesis of cardiovascular disease. Clinical studies have shown the benefit of MR blockade in patients with left ventricular dysfunction and heart failure after myocardial infarction (MI), hypertension or diabetic nephropathy. Deleterious effects of MR activation include cardiac structural and electrical remodelling, cardiovascular fibrosis, inflammation and oxidative stress. Complexity of pathophysiological role of MR derives from the presence of circulating glucocorticoids at higher concentrations than aldosterone and the equal affinity of the MR for aldosterone, cortisol and corticosterone. Recent experimental studies using different animal models and genetic tools have deeply explored the cell-specific functional role of MR in cardiovascular pathology. This review addresses emerging preclinical studies as well as ongoing clinical trials regarding MR activation in MI and failure.
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Affiliation(s)
- Paolo Galuppo
- Klinik fuer Kardiologie und Angiologie, Medizinische Hochschule Hannover, Hannover, Germany
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34
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T-type Ca2+ signalling downregulates MEK1/2 phosphorylation and cross-talk with the RAAS transcriptional response in cardiac myocytes. J Mol Cell Cardiol 2012; 53:291-8. [DOI: 10.1016/j.yjmcc.2012.05.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 05/09/2012] [Accepted: 05/10/2012] [Indexed: 12/23/2022]
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Zhou MS, Schulman IH, Zeng Q. Link between the renin-angiotensin system and insulin resistance: implications for cardiovascular disease. Vasc Med 2012; 17:330-41. [PMID: 22814999 DOI: 10.1177/1358863x12450094] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The incidence of metabolic syndrome is rapidly increasing in the United States and worldwide. The metabolic syndrome is a complex metabolic and vascular disorder that is associated with inappropriate activation of the renin-angiotensin-aldosterone system (RAAS) in the cardiovascular (CV) system and increased CV morbidity and mortality. Insulin activation of the phosphatidylinositol-3-kinase (PI3K) pathway promotes nitric oxide (NO) production in the endothelium and glucose uptake in insulin-sensitive tissues. Angiotensin (Ang) II inhibits insulin-mediated PI3K pathway activation, thereby impairing endothelial NO production and Glut-4 translocation in insulin-sensitive tissues, which results in vascular and systemic insulin resistance, respectively. On the other hand, Ang II enhances insulin-mediated activation of the mitogen-activated protein kinase (MAPK) pathway, which leads to vasoconstriction and pathologic vascular cellular growth. Therefore, the interaction of Ang II with insulin signaling is fully operative not only in insulin-sensitive tissues but also in CV tissues, thereby linking insulin resistance and CV disease. This notion is further supported by an increasing number of experimental and clinical studies indicating that pharmacological blockade of RAAS improves insulin sensitivity and endothelial function, as well as reduces the incidence of new-onset diabetes in high-risk patients with CV disease. This article reviews experimental and clinical data elucidating the physiological and pathophysiological role of the interaction between insulin and RAAS in the development of insulin resistance as well as CV disease.
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Affiliation(s)
- Ming-Sheng Zhou
- Nephrology-Hypertension Section, Veterans Affairs Medical Center, University of Miami Miller School of Medicine, Miami, FL 33125, USA.
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36
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Lee BL, Liu Y, Li X, Sykes BD, Fliegel L. Structural and functional analysis of extracellular loop 4 of the Nhe1 isoform of the Na(+)/H(+) exchanger. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:2783-90. [PMID: 22772156 DOI: 10.1016/j.bbamem.2012.06.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 06/26/2012] [Accepted: 06/27/2012] [Indexed: 12/29/2022]
Abstract
The mammalian Na(+)/H(+) exchanger isoform 1 (NHE1) is a ubiquitously expressed plasma membrane protein. It regulates intracellular pH by removing a single intracellular H(+) in exchange for one extracellular Na(+). The membrane domain of NHE1 comprises the 500 N-terminal amino acids and is made of 12 transmembrane segments. The extracellular loops of the transmembrane segments are thought to be involved in cation coordination and inhibitor sensitivity. We have characterized the structure and function of amino acids 278-291 representing extracellular loop 4. When mutated to Cys, residues F277, F280, N282 and E284 of EL4 were sensitive to mutation and reaction with MTSET inhibiting NHE1 activity. In addition they were found to be accessible to extracellular applied MTSET. A peptide of the amino acids of EL4 was mostly unstructured suggesting that it does not provide a rigid structured link between TM VII and TM VIII. Our results suggest that EL4 makes an extension upward from TM VII to make up part of the mouth of the NHE1 protein and is involved in cation selectivity or coordination. EL4 provides a flexible link to TM VIII which may either allow movement of TM VII or allow TM VIII to not be adjacent to TM VII.
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Affiliation(s)
- Brian L Lee
- Department of Biochemistry, University of Alberta, Alberta, Canada
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37
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Gender-specific effects of exercise on cardiac pathology in Na+/H+ exchanger overexpressing mice. Mol Cell Biochem 2012; 368:103-10. [DOI: 10.1007/s11010-012-1348-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 05/16/2012] [Indexed: 10/28/2022]
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Nariai T, Fujita K, Mori M, Katayama S, Hori S, Matsui K. Antihypertensive and cardiorenal protective effects of SM-368229, a novel mineralocorticoid receptor antagonist, in aldosterone/salt-treated rats. Pharmacology 2012; 89:44-52. [PMID: 22302095 DOI: 10.1159/000335559] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 12/05/2011] [Indexed: 12/21/2022]
Abstract
The purpose of this study was to evaluate the effects of SM-368229, a novel mineralocorticoid receptor (MR) antagonist, on the blood pressure and cardiorenal injury markers in aldosterone/salt-treated hypertensive rats, in comparison to those of spironolactone (SPI). Uninephrectomized rats, given 1% NaCl to drink, were infused with aldosterone (0.75 μg/h, s.c.). In experiment 1, SM-368229 (10, 30 mg/kg) or SPI (100 mg/kg) were administered for 14 days immediately after aldosterone/salt loading. In experiment 2, SM-368229 (10 mg/kg) or SPI (100 mg/kg) were administered for 10 days after 10 days of aldosterone/salt loading. In both experiments, SM-368229 prevented the increase in systolic blood pressure, heart/kidney weights, and urinary protein/N-acetyl-β-D- glucosaminidase excretion caused by aldosterone infusion. In real-time polymerase chain reaction analysis, SM-368229 abolished aldosterone-induced gene expression levels for inflammatory, fibrosis and oxidative stress markers in hearts and kidneys. The antihypertensive effect of SM-368229 (30 mg/kg) was superior to that of SPI, and the antihypertensive and cardiorenal protective effects of SM-368229 (10 mg/kg) were similar to those of SPI (100 mg/kg) in both experiments. These results clearly demonstrated that SM-368229 strongly attenuated the progression of hypertension and exerted cardiorenal protection in aldosterone/salt-treated hypertensive rats.
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Affiliation(s)
- Tetsuro Nariai
- Pharmacology, Dainippon Sumitomo Pharma Co., Osaka, Japan
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De Giusti VC, Nolly MB, Yeves AM, Caldiz CI, Villa-Abrille MC, Chiappe de Cingolani GE, Ennis IL, Cingolani HE, Aiello EA. Aldosterone Stimulates the Cardiac Na
+
/H
+
Exchanger via Transactivation of the Epidermal Growth Factor Receptor. Hypertension 2011; 58:912-9. [DOI: 10.1161/hypertensionaha.111.176024] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The use of antagonists of the mineralocorticoid receptor in the treatment of myocardial hypertrophy and heart failure has gained increasing importance in the last years. The cardiac Na
+
/H
+
exchanger (NHE-1) upregulation induced by aldosterone could account for the genesis of these pathologies. We tested whether aldosterone-induced NHE-1 stimulation involves the transactivation of the epidermal growth factor receptor (EGFR). Rat ventricular myocytes were used to measure intracellular pH with epifluorescence. Aldosterone enhanced the NHE-1 activity. This effect was canceled by spironolactone or eplerenone (mineralocorticoid receptor antagonists), but not by mifepristone (glucocorticoid receptor antagonist) or cycloheximide (protein synthesis inhibitor), indicating that the mechanism is mediated by the mineralocorticoid receptor triggering nongenomic pathways. Aldosterone-induced NHE-1 stimulation was abolished by the EGFR kinase inhibitor AG1478, suggesting that is mediated by transactivation of EGFR. The increase in the phosphorylation level of the kinase p90
RSK
and NHE-1 serine703 induced by aldosterone was also blocked by AG1478. Exogenous epidermal growth factor mimicked the effects of aldosterone on NHE-1 activity. Epidermal growth factor was also able to increase reactive oxygen species production, and the epidermal growth factor–induced activation of the NHE-1 was abrogated by the reactive oxygen species scavenger
N
-2-mercaptopropionyl glycine, indicating that reactive oxygen species are participating as signaling molecules in this mechanism. Aldosterone enhances the NHE-1 activity via transactivation of the EGFR, formation of reactive oxygen species, and phosphorylation of the exchanger. These results call attention to the consideration of the EGFR as a new potential therapeutic target of the cardiovascular pathologies involving the participation of aldosterone.
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Affiliation(s)
- Verónica C. De Giusti
- From the Centro de Investigaciones Cardiovasculares (CONICET), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Mariela B. Nolly
- From the Centro de Investigaciones Cardiovasculares (CONICET), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Alejandra M. Yeves
- From the Centro de Investigaciones Cardiovasculares (CONICET), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Claudia I. Caldiz
- From the Centro de Investigaciones Cardiovasculares (CONICET), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - María C. Villa-Abrille
- From the Centro de Investigaciones Cardiovasculares (CONICET), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Gladys E. Chiappe de Cingolani
- From the Centro de Investigaciones Cardiovasculares (CONICET), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Irene L. Ennis
- From the Centro de Investigaciones Cardiovasculares (CONICET), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Horacio E. Cingolani
- From the Centro de Investigaciones Cardiovasculares (CONICET), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Ernesto A. Aiello
- From the Centro de Investigaciones Cardiovasculares (CONICET), Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
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Elevated expression of activated Na(+)/H(+) exchanger protein induces hypertrophy in isolated rat neonatal ventricular cardiomyocytes. Mol Cell Biochem 2011; 358:179-87. [PMID: 21720766 DOI: 10.1007/s11010-011-0933-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 06/21/2011] [Indexed: 10/18/2022]
Abstract
The plasma membrane protein the Na(+)/H(+) exchanger isoform1 (NHE1) has been implicated in various cardiac pathologies including ischemia/reperfusion damage to the myocardium and cardiac hypertrophy. Levels of NHE1 protein and activity are elevated in cardiac disease; however, the mechanism by which these factors contribute to the accompanying hypertrophy in the myocardium is still not clear. To investigate the mechanism of NHE1-induced hypertrophy in the myocardium we constructed two adenoviral vectors expressing either wild type NHE1 protein or a constitutively active NHE1 protein. Infection of neonatal rat ventricular cardiomyocytes (NRVM) resulted in elevated expression of both wild type NHE1 or constitutively active NHE1. Only expression of activated NHE1 protein resulted in an increase in cell size and in an increase in protein synthesis in isolated cardiomyocyte cells. The results demonstrate that expression of activated NHE1 promotes cardiac hypertrophy in isolated cardiac cells and that simple elevation of levels of wild type NHE1 protein does not have a significant hypertrophic effect in NRVM. The results suggest that regulation of NHE1 activity is a critical direct effector of the hypertrophic effect induced in the myocardium by the NHE1 protein.
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Szymański P, Klisiewicz A, Lubiszewska B, Lipczyńska M, Kowalski M, Janas J, Hoffman P. Gender differences in angiotensin II and aldosterone secretion in patients with pressure overloaded systemic right ventricles are similar to those observed in systemic arterial hypertension. Int J Cardiol 2011; 147:366-70. [DOI: 10.1016/j.ijcard.2009.09.535] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 08/24/2009] [Accepted: 09/25/2009] [Indexed: 11/25/2022]
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Mraiche F, Oka T, Gan XT, Karmazyn M, Fliegel L. Activated NHE1 is required to induce early cardiac hypertrophy in mice. Basic Res Cardiol 2011; 106:603-16. [PMID: 21359875 DOI: 10.1007/s00395-011-0161-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2010] [Revised: 12/07/2010] [Accepted: 12/13/2010] [Indexed: 01/13/2023]
Abstract
The Na+/H+ exchanger isoform 1 (NHE1) has been implicated as being causal in cardiac hypertrophy and the protein level and activity are elevated in the diseased myocardium. However, it is unclear whether mere elevation of the protein is sufficient for cardiac pathology, or whether activation of the protein is required. In this study, we examined the comparative effects of elevation of wild type and activated NHE1. Two mouse transgenic models that expressed either a wild type NHE1 protein or an activated NHE1 protein were characterized. Expression of activated NHE1 caused significant increases in heart weight to body weight, apoptosis, cross-sectional area, interstitial fibrosis and decreased cardiac performance. Expression of wild type NHE1 caused a much milder pathology. When we examined 2 or 10-week-old mouse hearts, there was neither elevation of calcineurin levels nor increased phosphorylation of ERK or p38 in either NHE1 transgenic mouse line. Expression of activated NHE1 in intact mice caused an increased sensitivity to phenylephrine-induced hypertrophy. Our results show that expression of activated NHE1 promotes cardiac hypertrophy to a much greater degree than elevated levels of wild type NHE1 alone. In addition, expression of activated NHE1 promotes greater sensitivity to neurohormonal stimulation. The results suggest that activation of NHE1 is a key component that accentuates NHE1-induced myocardial pathology.
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Affiliation(s)
- Fatima Mraiche
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
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Tzeng J, Lee BL, Sykes BD, Fliegel L. Structural and functional analysis of transmembrane segment VI of the NHE1 isoform of the Na+/H+ exchanger. J Biol Chem 2010; 285:36656-65. [PMID: 20843797 PMCID: PMC2978594 DOI: 10.1074/jbc.m110.161471] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 08/23/2010] [Indexed: 01/17/2023] Open
Abstract
The Na(+)/H(+) exchanger isoform 1 is a ubiquitously expressed integral membrane protein. It resides on the plasma membrane of cells and regulates intracellular pH in mammals by extruding an intracellular H(+) in exchange for one extracellular Na(+). We characterized structural and functional aspects of the transmembrane segment (TM) VI (residues 227-249) by using cysteine scanning mutagenesis and high resolution NMR. Each residue of TM VI was mutated to cysteine in the background of the cysteineless NHE1 protein, and the sensitivity to water-soluble sulfhydryl-reactive compounds (2-(trimethylammonium)ethyl)methanethiosulfonate (MTSET) and (2-sulfonatoethyl)methanethiosulfonate (MTSES) was determined for those residues with significant activity remaining. Three residues were essentially inactive when mutated to Cys: Asp(238), Pro(239), and Glu(247). Of the remaining residues, proteins with the mutations N227C, I233C, and L243C were strongly inhibited by MTSET, whereas amino acids Phe(230), Gly(231), Ala(236), Val(237), Ala(244), Val(245), and Glu(248) were partially inhibited by MTSET. MTSES did not affect the activity of the mutant NHE1 proteins. The structure of a peptide representing TM VI was determined using high resolution NMR spectroscopy in dodecylphosphocholine micelles. TM VI contains two helical regions oriented at an approximate right angle to each other (residues 229-236 and 239-250) surrounding a central unwound region. This structure bears a resemblance to TM IV of the Escherichia coli protein NhaA. The results demonstrate that TM VI of NHE1 is a discontinuous pore-lining helix with residues Asn(227), Ile(233), and Leu(243) lining the translocation pore.
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Affiliation(s)
- Jennifer Tzeng
- From the Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Brian L. Lee
- From the Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Brian D. Sykes
- From the Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Larry Fliegel
- From the Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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Mraiche F, Wagg CS, Lopaschuk GD, Fliegel L. Elevated levels of activated NHE1 protect the myocardium and improve metabolism following ischemia/reperfusion injury. J Mol Cell Cardiol 2010; 50:157-64. [PMID: 20974148 DOI: 10.1016/j.yjmcc.2010.10.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 10/01/2010] [Accepted: 10/16/2010] [Indexed: 01/25/2023]
Abstract
In the myocardium, the Na(+)/H(+) exchanger isoform 1 (NHE1) is a plasma membrane protein that regulates intracellular pH. Inhibition of NHE1 activity has been shown to be beneficial in cardiovascular disease. However, recent reports have suggested that elevation of NHE1 levels has beneficial effects in hearts subjected to ischemia/reperfusion. We determined if activated and non-activated NHE1 proteins have varying cardioprotective and metabolic effects with ischemia/reperfusion in the isolated perfused working mouse heart. We used transgenic mice hearts that specifically expressed wild type NHE1 (N-line) or activated NHE1 protein (K-line). Intact hearts 10-12 weeks of age were perfused under working conditions, with fatty acids and glucose present as substrates. Hearts were subjected to 30 min of aerobic perfusion, followed by 20 min of global no-flow ischemia and 40 min of aerobic reperfusion. We examined changes in contractility and substrate use and ATP levels. K-line hearts expressing activated NHE1, recovered to a much greater extent than N-line and control hearts recovering almost 75% of their preischemic function. In addition, K-line hearts had elevated fatty acid oxidation, increased glycolysis rates and elevated ATP levels relative to N-line mice or controls. An examination of kinase activation showed that there were no differences between controls and transgenics in ERK, p38, p90(rsk) or pGSK3β levels. The results demonstrate that elevated levels of NHE1 induce cardioprotection and alter cardiac metabolism. However, in the working heart model, with glucose and fatty acid as substrates, this required an activated NHE1 protein.
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Affiliation(s)
- Fatima Mraiche
- Department of Pediatrics, University of Alberta, Edmonton, AB T6G 2H7, Canada
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Xue J, Mraiche F, Zhou D, Karmazyn M, Oka T, Fliegel L, Haddad GG. Elevated myocardial Na+/H+ exchanger isoform 1 activity elicits gene expression that leads to cardiac hypertrophy. Physiol Genomics 2010; 42:374-83. [PMID: 20460605 DOI: 10.1152/physiolgenomics.00064.2010] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
In myocardial disease, elevated expression and activity of Na(+)/H(+) exchanger isoform 1 (NHE1) are detrimental. To better understand the involvement of NHE1, transgenic mice with elevated heart-specific NHE1 expression were studied. N-line mice expressed wild-type NHE1, and K-line mice expressed activated NHE1. Cardiac morphology, interstitial fibrosis, and cardiac function were examined by histological staining and echocardiography. Differences in gene expression between the N-line or K-line and nontransgenic littermates were probed with genechip analysis. We found that NHE1 K-line (but not N-line) hearts developed hypertrophy, including elevated heart weight-to-body weight ratio and increased cross-sectional area of the cardiomyocytes, interstitial fibrosis, as well as depressed cardiac function. N-line hearts had modest changes in gene expression (50 upregulations and 99 downregulations, P < 0.05), whereas K-line hearts had a very strong transcriptional response (640 upregulations and 677 downregulations, P < 0.05). In addition, the magnitude of expression alterations was much higher in K-line than N-line mice. The most significant changes in gene expression were involved in cardiac hypertrophy, cardiac necrosis/cell death, and cardiac infarction. Secreted phosphoprotein 1 and its signaling pathways were upregulated while peroxisome proliferator-activated receptor gamma signaling was downregulated in K-line mice. Our study shows that expression of activated NHE1 elicits specific pathways of gene activation in the myocardium that lead to cardiac hypertrophy, cell death, and infarction.
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Affiliation(s)
- Jin Xue
- Department of Pediatrics, University of California San Diego, La Jolla, California 92093-0735, USA
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Reddy T, Li X, Fliegel L, Sykes BD, Rainey JK. Correlating structure, dynamics, and function in transmembrane segment VII of the Na+/H+ exchanger isoform 1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:94-104. [DOI: 10.1016/j.bbamem.2009.06.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Revised: 06/17/2009] [Accepted: 06/29/2009] [Indexed: 10/20/2022]
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Vasculoprotective effect of cilostazol in aldosterone-induced hypertensive rats. Hypertens Res 2009; 33:229-35. [DOI: 10.1038/hr.2009.211] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Cetrullo S, Facchini A, Stanic I, Tantini B, Pignatti C, Caldarera CM, Flamigni F. Difluoromethylornithine inhibits hypertrophic, pro-fibrotic and pro-apoptotic actions of aldosterone in cardiac cells. Amino Acids 2009; 38:525-31. [DOI: 10.1007/s00726-009-0413-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Accepted: 09/06/2009] [Indexed: 10/20/2022]
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Lee BL, Li X, Liu Y, Sykes BD, Fliegel L. Structural and functional analysis of extracellular loop 2 of the Na+/H+ exchanger. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:2481-8. [DOI: 10.1016/j.bbamem.2009.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Revised: 09/30/2009] [Accepted: 10/06/2009] [Indexed: 10/20/2022]
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Zhang M, Chen J, Liu S, You L, Lin S, Gu Y. The Role of Na+-H+Exchanger Isoform 1 in Aldosterone-Induced Glomerulosclerosis in Vivo. Ren Fail 2009; 31:726-35. [DOI: 10.3109/08860220903134571] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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