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Funato Y, Yamazaki D, Okuzaki D, Yamamoto N, Miki H. Importance of the renal ion channel TRPM6 in the circadian secretion of renin to raise blood pressure. Nat Commun 2021; 12:3683. [PMID: 34140503 PMCID: PMC8211686 DOI: 10.1038/s41467-021-24063-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 06/01/2021] [Indexed: 11/30/2022] Open
Abstract
Blood pressure has a daily pattern, with higher values in the active period. Its elevation at the onset of the active period substantially increases the risk of fatal cardiovascular events. Renin secretion stimulated by renal sympathetic neurons is considered essential to this process; however, its regulatory mechanism remains largely unknown. Here, we show the importance of transient receptor potential melastatin-related 6 (TRPM6), a Mg2+-permeable cation channel, in augmenting renin secretion in the active period. TRPM6 expression is significantly reduced in the distal convoluted tubule of hypotensive Cnnm2-deficient mice. We generate kidney-specific Trpm6-deficient mice and observe a decrease in blood pressure and a disappearance of its circadian variation. Consistently, renin secretion is not augmented in the active period. Furthermore, renin secretion after pharmacological activation of β-adrenoreceptor, the target of neuronal stimulation, is abrogated, and the receptor expression is decreased in renin-secreting cells. These results indicate crucial roles of TRPM6 in the circadian regulation of blood pressure. Circadian variation of blood pressure, with higher values in the active period, is associated with the risk of fatal cardiovascular events. Here, we show the importance of renal TRPM6, a Magnesium-permeable cation channel, in raising blood pressure by stimulating renin secretion.
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Affiliation(s)
- Yosuke Funato
- Department of Cellular Regulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Daisuke Yamazaki
- Department of Cellular Regulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Daisuke Okuzaki
- Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Nobuhiko Yamamoto
- Neuroscience Laboratories, Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Hiroaki Miki
- Department of Cellular Regulation, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
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2
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Bernardi J, Aromolaran KA, Zhu H, Aromolaran AS. Circadian Mechanisms: Cardiac Ion Channel Remodeling and Arrhythmias. Front Physiol 2021; 11:611860. [PMID: 33519516 PMCID: PMC7841411 DOI: 10.3389/fphys.2020.611860] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/18/2020] [Indexed: 12/31/2022] Open
Abstract
Circadian rhythms are involved in many physiological and pathological processes in different tissues, including the heart. Circadian rhythms play a critical role in adverse cardiac function with implications for heart failure and sudden cardiac death, highlighting a significant contribution of circadian mechanisms to normal sinus rhythm in health and disease. Cardiac arrhythmias are a leading cause of morbidity and mortality in patients with heart failure and likely cause ∼250,000 deaths annually in the United States alone; however, the molecular mechanisms are poorly understood. This suggests the need to improve our current understanding of the underlying molecular mechanisms that increase vulnerability to arrhythmias. Obesity and its associated pathologies, including diabetes, have emerged as dangerous disease conditions that predispose to adverse cardiac electrical remodeling leading to fatal arrhythmias. The increasing epidemic of obesity and diabetes suggests vulnerability to arrhythmias will remain high in patients. An important objective would be to identify novel and unappreciated cellular mechanisms or signaling pathways that modulate obesity and/or diabetes. In this review we discuss circadian rhythms control of metabolic and environmental cues, cardiac ion channels, and mechanisms that predispose to supraventricular and ventricular arrhythmias including hormonal signaling and the autonomic nervous system, and how understanding their functional interplay may help to inform the development and optimization of effective clinical and therapeutic interventions with implications for chronotherapy.
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Affiliation(s)
- Joyce Bernardi
- Masonic Medical Research Institute, Utica, NY, United States
| | | | - Hua Zhu
- Department of Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, United States
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D'Souza A, Wang Y, Anderson C, Bucchi A, Baruscotti M, Olieslagers S, Mesirca P, Johnsen AB, Mastitskaya S, Ni H, Zhang Y, Black N, Cox C, Wegner S, Bano-Otalora B, Petit C, Gill E, Logantha SJRJ, Dobrzynski H, Ashton N, Hart G, Zhang R, Zhang H, Cartwright EJ, Wisloff U, Mangoni ME, da Costa Martins PA, Piggins HD, DiFrancesco D, Boyett MR. A circadian clock in the sinus node mediates day-night rhythms in Hcn4 and heart rate. Heart Rhythm 2020; 18:801-810. [PMID: 33278629 PMCID: PMC8073545 DOI: 10.1016/j.hrthm.2020.11.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 11/09/2020] [Accepted: 11/21/2020] [Indexed: 11/26/2022]
Abstract
Background Heart rate follows a diurnal variation, and slow heart rhythms occur primarily at night. Objective The lower heart rate during sleep is assumed to be neural in origin, but here we tested whether a day-night difference in intrinsic pacemaking is involved. Methods In vivo and in vitro electrocardiographic recordings, vagotomy, transgenics, quantitative polymerase chain reaction, Western blotting, immunohistochemistry, patch clamp, reporter bioluminescence recordings, and chromatin immunoprecipitation were used. Results The day-night difference in the average heart rate of mice was independent of fluctuations in average locomotor activity and persisted under pharmacological, surgical, and transgenic interruption of autonomic input to the heart. Spontaneous beating rate of isolated (ie, denervated) sinus node (SN) preparations exhibited a day-night rhythm concomitant with rhythmic messenger RNA expression of ion channels including hyperpolarization-activated cyclic nucleotide-gated potassium channel 4 (HCN4). In vitro studies demonstrated 24-hour rhythms in the human HCN4 promoter and the corresponding funny current. The day-night heart rate difference in mice was abolished by HCN block, both in vivo and in the isolated SN. Rhythmic expression of canonical circadian clock transcription factors, for example, Brain and muscle ARNT-Like 1 (BMAL1) and Cryptochrome (CRY) was identified in the SN and disruption of the local clock (by cardiomyocyte-specific knockout of Bmal1) abolished the day-night difference in Hcn4 and intrinsic heart rate. Chromatin immunoprecipitation revealed specific BMAL1 binding sites on Hcn4, linking the local clock with intrinsic rate control. Conclusion The circadian variation in heart rate involves SN local clock–dependent Hcn4 rhythmicity. Data reveal a novel regulator of heart rate and mechanistic insight into bradycardia during sleep.
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Affiliation(s)
- Alicia D'Souza
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom.
| | - Yanwen Wang
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Cali Anderson
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Annalisa Bucchi
- Department of Biosciences, University of Milan, Milan, Italy
| | | | - Servé Olieslagers
- Department of Cardiology, Maastricht University, Maastricht, The Netherlands
| | - Pietro Mesirca
- Institut de Génomique Fonctionnelle, Université de Montpellie, CNRS, Montpellier, France
| | - Anne Berit Johnsen
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway
| | - Svetlana Mastitskaya
- Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Haibo Ni
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Yu Zhang
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Nicholas Black
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Charlotte Cox
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Sven Wegner
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Beatriz Bano-Otalora
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Cheryl Petit
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Eleanor Gill
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Sunil Jit R J Logantha
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom; Liverpool Centre for Cardiovascular Sciences, University of Liverpool, Liverpool, UK
| | - Halina Dobrzynski
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Nick Ashton
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - George Hart
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Rai Zhang
- School of Civil, Aerospace and Mechanical Engineering, University of Bristol, Bristol, United Kingdom
| | - Henggui Zhang
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Elizabeth J Cartwright
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Ulrik Wisloff
- Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway
| | - Matteo E Mangoni
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Hugh D Piggins
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Dario DiFrancesco
- Department of Biosciences, University of Milan, Milan, Italy; IBF-CNR, Milan, Italy
| | - Mark R Boyett
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Acute restraint stress modifies the heart rate biorhythm in the poststress period. Sci Rep 2019; 9:1794. [PMID: 30742021 PMCID: PMC6370754 DOI: 10.1038/s41598-019-38523-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 12/28/2018] [Indexed: 11/13/2022] Open
Abstract
We studied the changes in the heart and the activity biorhythms in mice exposed to acute (one 120-minute session) and repeated (7 two-hour sessions) restraint stress in 129J1/CF1 mice (WT) and in mice without M2 muscarinic receptors (M2KO) during the prestress period, during stress (STR) and for five days after the last stress session (POST). There were changes in the mesor (a midline based on the distribution of values across the circadian cycles; decreased in M2KO by 6% over all POST), day means (inactive period of diurnal rhythm in mice; higher in M2KO and further increased on STR and on the second to the fifth POST) and night means (active period; lower by 13% in M2KO and remained decreased in STR and in POST). The total area under the curve was decreased both in the WT and M2KO on STR and in all POST. Repeated stress caused changes over all days of STR, but the initial values were restored in POST. The average night values were decreased, and the day means were increased by 16% over all STR in M2KO. The day means decreased by 14% in the 4 POST in WT. The activity biorhythm parameters were almost unchanged. We show here that stress can specifically affect heart biorhythm in M2KO mice, especially when the stress is acute. This implies the role of M2 muscarinic receptor in stress response.
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Black N, D'Souza A, Wang Y, Piggins H, Dobrzynski H, Morris G, Boyett MR. Circadian rhythm of cardiac electrophysiology, arrhythmogenesis, and the underlying mechanisms. Heart Rhythm 2018; 16:298-307. [PMID: 30170229 PMCID: PMC6520649 DOI: 10.1016/j.hrthm.2018.08.026] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Indexed: 12/31/2022]
Abstract
Cardiac arrhythmias are a leading cause of cardiovascular death. It has long been accepted that life-threatening cardiac arrhythmias (ventricular tachycardia, ventricular fibrillation, and sudden cardiac death) are more likely to occur in the morning after waking. It is perhaps less well recognized that there is a circadian rhythm in cardiac pacemaking and other electrophysiological properties of the heart. In addition, there is a circadian rhythm in other arrhythmias, for example, bradyarrhythmias and supraventricular arrhythmias. Two mechanisms may underlie this finding: (1) a central circadian clock in the suprachiasmatic nucleus in the hypothalamus may directly affect the electrophysiology of the heart and arrhythmogenesis via various neurohumoral factors, particularly the autonomic nervous system; or (2) a local circadian clock in the heart itself (albeit under the control of the central clock) may drive a circadian rhythm in the expression of ion channels in the heart, which in turn varies arrhythmic substrate. This review summarizes the current understanding of the circadian rhythm in cardiac electrophysiology, arrhythmogenesis, and the underlying molecular mechanisms.
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Affiliation(s)
- Nicholas Black
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Alicia D'Souza
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Yanwen Wang
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Hugh Piggins
- Division of Diabetes, Endocrinology & Gastroenterology, University of Manchester, Manchester, United Kingdom
| | - Halina Dobrzynski
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Gwilym Morris
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom
| | - Mark R Boyett
- Division of Cardiovascular Sciences, University of Manchester, Manchester, United Kingdom.
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Yu B, Cai D. Neural Programmatic Role of Leptin, TNFα, Melanocortin, and Glutamate in Blood Pressure Regulation vs Obesity-Related Hypertension in Male C57BL/6 Mice. Endocrinology 2017; 158:1766-1775. [PMID: 28419227 PMCID: PMC5460935 DOI: 10.1210/en.2016-1872] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Accepted: 04/10/2017] [Indexed: 02/07/2023]
Abstract
Continuous nutritional surplus sets the stage for hypertension development. Whereas moderate dietary obesity in mice is normotensive, the homeostatic balance is disrupted concurrent with an increased risk of hypertension. However, it remains unclear how the obesity-associated prehypertensive state is converted into overt hypertension. Here, using mice with high-fat-diet (HFD)-induced moderate obesity vs control diet (CD)-fed lean mice, we comparatively studied the effects of central leptin and tumor necrosis factor-α (TNFα) as well as the involvement of the neuropeptide melanocortin pathway vs the neurotransmitter glutamate pathway. Compared with CD-fed lean mice, the pressor effect of central excess leptin and TNFα, but not melanocortin, was sensitized in HFD-fed mice. The pressor effect of central leptin in HFD-fed mice was strongly suppressed by glutamatergic inhibition but not by melanocortinergic inhibition. The pressor effect of central TNFα was substantially reversed by melanocortinergic inhibition in HFD-fed mice but barely in CD-fed mice. Regardless of diet, the hypertensive effects of central TNFα and melanocortin were both partially reversed by glutamatergic suppression. Hence, neural control of blood pressure is mediated by a signaling network between leptin, TNFα, melanocortin, and glutamate and changes in dynamics due to central excess leptin and TNFα mediate the switch from normal physiology to obesity-related hypertension.
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Affiliation(s)
- Bin Yu
- Department of Molecular Pharmacology, Diabetes Research Center, Institute of Aging, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Dongsheng Cai
- Department of Molecular Pharmacology, Diabetes Research Center, Institute of Aging, Albert Einstein College of Medicine, Bronx, New York 10461
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Tsuchiya S, Higashide T, Toida K, Sugiyama K. The Role of Beta-Adrenergic Receptors in the Regulation of Circadian Intraocular Pressure Rhythm in Mice. Curr Eye Res 2017; 42:1013-1017. [PMID: 28121174 DOI: 10.1080/02713683.2016.1264605] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE To investigate whether the elimination of β1- and β2-adrenergic receptors alters the diurnal intraocular pressure (IOP) rhythm in mice. MATERIALS AND METHODS β1-/β2-adrenergic receptor double-knockout and C57BL/6J mice were anesthetized intraperitoneally, with their IOPs measured via microneedle method. After entrainment to a 12-h light-dark (LD) cycle (light phase 6:00-18:00), IOPs were measured every 3 h from 9:00 to 24:00 (group 1, β1-/β2-adrenergic receptor double-knockout mice, n = 11; C57BL/6J, n = 15). The IOP measurements at 15:00 and 24:00 under a 12-h LD cycle and in the constant darkness (1 day and 8 days after exposure to darkness, respectively) were performed in another group of β1-/β2-adrenergic receptor double-knockout mice (group 2, n = 12). IOP variance throughout the day and mean IOP differences among time points were evaluated using a linear mixed model. RESULTS β1-/β2-adrenergic receptor double-knockout and C57BL/6J mice showed biphasic IOP curves, low during the light phase and high during the dark phase; the fluctuation was significant (P < 0.001). The peak IOP (18.7 ± 1.4 mmHg) occurred at 24:00 and the trough IOP (13.5 ± 1.5 mmHg) occurred at 15:00 in β1-/β2-adrenergic receptor double-knockout mice group. IOP curves of β1-/β2-adrenergic receptor double-knockout and C57BL/6J were nearly parallel, and the IOPs of β1-/β2-adrenergic receptor double-knockout mice were significantly higher than those of C57BL/6J mice (P < 0.001). Under constant dark (DD) conditions, IOP at 24:00 (18.1 ± 1.5 mmHg) was significantly higher than that at 15:00 (13.3 ± 1.2 mmHg) (P < 0.001). The transition from the LD cycle to DD environment produced no significant change in IOP (P = 0.728). CONCLUSIONS Elimination of both β1- and β2-adrenergic receptors did not disturb the biphasic diurnal IOP rhythm in mice.
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Affiliation(s)
- Shunsuke Tsuchiya
- a Department of Ophthalmology and Visual Science , Kanazawa University Graduate School of Medical Science , Kanazawa , Japan
| | - Tomomi Higashide
- a Department of Ophthalmology and Visual Science , Kanazawa University Graduate School of Medical Science , Kanazawa , Japan
| | - Kazunori Toida
- b Department of Anatomy , Kawasaki Medical School , Kurashiki , Japan.,c Research Center for Ultra-High Voltage Electron Microscopy , Osaka University , Ibaraki , Japan
| | - Kazuhisa Sugiyama
- a Department of Ophthalmology and Visual Science , Kanazawa University Graduate School of Medical Science , Kanazawa , Japan
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Huang Y, Liu XL, Wen J, Huang LH, Lu Y, Miao RJ, Liu X, Li Y, Xing XW, Yuan H. Downregulation of the β1 adrenergic receptor in the myocardium results in insensitivity to metoprolol and reduces blood pressure in spontaneously hypertensive rats. Mol Med Rep 2016; 15:703-711. [PMID: 28000860 PMCID: PMC5364866 DOI: 10.3892/mmr.2016.6038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 09/08/2016] [Indexed: 01/08/2023] Open
Abstract
The β1‑adrenergic receptor (AR) is the primary β‑AR subtype in the heart and is the target of metoprolol (Met), which is commonly used to treat angina and hypertension. Previous studies have revealed a positive correlation between the methylation levels of the adrenoreceptor β1 gene (Adrb1) promoter in the myocardium with the antihypertensive activity of Met in spontaneously hypertensive rats (SHR), which affects β1‑AR expression in H9C2 cells. The aim of the present study was to investigate the effects of myocardial β1‑AR downregulation using short‑hairpin RNA (shRNA) against Adrb1 on the antihypertensive activity of Met in SHR. Recombinant adeno‑associated virus type 9 (rAAV9) vectors carrying Adrb1 shRNA (rAAV9‑Adrb1) or a negative control sequence (rAAV9‑NC) were generated and used to infect rat hearts via the pericardial cavity. The results of reverse transcription‑quantitative polymerase chain reaction, immunohistochemistry and western blotting analyses demonstrated that cardiac β1‑AR expression in the rAAV9‑Adrb1 group was significantly downregulated when compared with the rAAV9‑NC group (P<0.001, P<0.001 and P=0.032, respectively). In addition, a greater reduction in systolic blood pressure (SBP) was observed in the rAAV9‑NC group compared with the rAAV9‑Adrb1 group following Met treatment (P=0.035). Furthermore, downregulation of myocardial β1‑AR was associated with a significant decrease in SBP (P<0.001). In conclusion, these data suggest that suppression of β1‑AR expression in the myocardium reduces SBP and sensitivity to Met in SHR.
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Affiliation(s)
- Yun Huang
- Center for Clinical Pharmacology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China
| | - Xiao-Li Liu
- Department of Pharmacy, The Second Affiliated Hospital of Hunan University of Traditional Chinese Medicine, Changsha, Hunan 410013, P.R. China
| | - Jia Wen
- Center for Clinical Pharmacology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China
| | - Li-Hua Huang
- Center for Clinical Pharmacology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China
| | - Yao Lu
- Center for Clinical Pharmacology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China
| | - Ru-Jia Miao
- Center for Clinical Pharmacology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China
| | - Xing Liu
- Center for Clinical Pharmacology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China
| | - Ying Li
- Center for Clinical Pharmacology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China
| | - Xiao-Wei Xing
- Center for Clinical Pharmacology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China
| | - Hong Yuan
- Center for Clinical Pharmacology, The Third Xiangya Hospital, Central South University, Changsha, Hunan 410013, P.R. China
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Differential impact of type-1 and type-2 diabetes on control of heart rate in mice. Auton Neurosci 2015; 194:17-25. [PMID: 26725752 DOI: 10.1016/j.autneu.2015.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Revised: 11/23/2015] [Accepted: 12/14/2015] [Indexed: 01/14/2023]
Abstract
AIMS Cardiac autonomic dysfunction is a serious complication of diabetes. One consequence is disruption of the normal beat-to-beat regulation of heart rate (HR), i.e. HR variability (HRV). However, our understanding of the disease process has been limited by inconsistent HR/HRV data from previous animal studies. We hypothesized that differences in the method of measurement, time of day, and level of stress account for the differing results across studies. Thus, our aim was to systematically assess HR and HRV in two common diabetic mouse models. METHODS ECG radiotelemetry devices were implanted into db/db (type-2 diabetic), STZ-treated db/+ (type-1 diabetic), and control db/+ mice (n=4 per group). HR and HRV were analyzed over 24 h and during treadmill testing. RESULTS 24 h analysis revealed that db/db mice had an altered pattern of circadian HR changes, and STZ-treated mice had reduced HR throughout. HRV measures linked to sympathetic control were reduced in db/db mice in the early morning and early afternoon, and partially reduced in STZ-treated mice. HR response to treadmill testing was blunted in both models. CONCLUSIONS It is important to consider both time of day and level of stress when assessing HR and HRV in diabetic mice. db/db mice may have altered circadian rhythm of sympathetic control of HR, whereas STZ-treated mice have a relative reduction. This study provides baseline data and a framework for HR analysis that may guide future investigations.
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Kim SM, Mizel D, Qin Y, Huang Y, Schnermann J. Blood pressure, heart rate and tubuloglomerular feedback in A1AR-deficient mice with different genetic backgrounds. Acta Physiol (Oxf) 2015; 213:259-67. [PMID: 25182861 DOI: 10.1111/apha.12377] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 07/28/2014] [Accepted: 08/27/2014] [Indexed: 01/11/2023]
Abstract
AIM Differences in genetic background between control mice and mice with targeted gene mutations have been recognized as a potential cause for phenotypic differences. In this study, we have used A1AR-deficient mice in a C57Bl/6 and SWR/J congenic background to assess the influence of background on the effect of A1AR-deficiency on cardiovascular and renal functional parameters. METHODS In A1AR+/+ and A1AR-/- mice in C57Bl/6 and SWR/J congenic backgrounds, we assessed blood pressure and heart rate using radio-telemetry, plasma renin concentrations and tubuloglomerular feedback. RESULTS We did not detect significant differences in arterial blood pressure (MAP) and heart rates (HR) between A1AR+/+ and A1AR-/- mice in either C57Bl/6, SWR/J or mixed backgrounds. MAP and HR were significantly higher in SWR/J than in C57Bl/6 mice. A high NaCl intake increased MAP in A1AR-/- mice on C57Bl/6 background while there was less or no salt sensitivity in the SWR/J background. No significant differences in plasma renin concentration were detected between A1AR-/- and A1AR+/+ mice in any of the strains. Tubuloglomerular feedback was found to be absent in A1AR-/- mice with SWR/J genetic background. CONCLUSIONS While this study confirmed important differences between inbred mouse strains, we did not identify phenotypic modifications of A1AR-related effects on blood pressure, heart rate and plasma renin by differences in genetic background.
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Affiliation(s)
- S. M. Kim
- Department of Physiology; Chonbuk National University Medical School; Jeonju South Korea
- National Institute of Diabetes and Digestive and Kidney Diseases; NIH; Bethesda Maryland
| | - D. Mizel
- National Institute of Diabetes and Digestive and Kidney Diseases; NIH; Bethesda Maryland
| | - Y. Qin
- National Institute of Diabetes and Digestive and Kidney Diseases; NIH; Bethesda Maryland
| | - Y. Huang
- National Institute of Diabetes and Digestive and Kidney Diseases; NIH; Bethesda Maryland
| | - J. Schnermann
- National Institute of Diabetes and Digestive and Kidney Diseases; NIH; Bethesda Maryland
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Pillas D, Kaakinen M, Tzoulaki I, Netuveli G, Rodriguez A, Fung E, Tammelin TH, Blane D, Millwood IY, Hardy R, Sovio U, Pouta A, Hopstock LA, Hartikainen AL, Laitinen J, Vaara S, Khan AA, Chong R, Elliott P, Jarvelin MR. Infant locomotive development and its association with adult blood pressure. Eur J Pediatr 2014; 173:1309-17. [PMID: 24804637 DOI: 10.1007/s00431-014-2326-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 04/18/2014] [Accepted: 04/21/2014] [Indexed: 11/29/2022]
Abstract
UNLABELLED Evidence from animal models suggests that locomotion and blood pressure share common neurophysiological regulatory systems. As a result of this common regulation, we hypothesized that the development of locomotion in human infants would be associated with blood pressure levels in adulthood. The study sample comprised 4,347 individuals with measures of locomotive and non-locomotive neuromotor development in infancy and adult blood pressure levels within a longitudinal birth cohort study, the Northern Finland Birth Cohort 1966. Later development in all three stages of locomotive development during infancy was associated with higher systolic and diastolic blood pressure levels at age 31. For age of walking without support, 0.34 (95 % CI 0.07 to 0.60)-mm Hg higher SBP and 0.38 (95 % CI 0.15 to 0.62)-mm Hg higher DBP were estimated for each month of later achievement (P = 0.012 for SBP; P = 0.001 for DBP). No association was identified for non-locomotive neuromotor development. CONCLUSION These results highlight the positive sequelae of advanced locomotive development during infancy, suggesting that the common regulatory systems between locomotion and blood pressure may influence the development of raised blood pressure over time.
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Affiliation(s)
- Demetris Pillas
- Department of Epidemiology and Biostatistics, Imperial College London, Norfolk Place, London, W2 1PG, UK,
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Kim SM, Briggs JP, Schnermann J. Convergence of major physiological stimuli for renin release on the Gs-alpha/cyclic adenosine monophosphate signaling pathway. Clin Exp Nephrol 2011; 16:17-24. [PMID: 22124804 DOI: 10.1007/s10157-011-0494-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2009] [Accepted: 03/23/2011] [Indexed: 12/29/2022]
Abstract
Control of the renin system by physiological mechanisms such as the baroreceptor or the macula densa (MD) is characterized by asymmetry in that the capacity for renin secretion and expression to increase is much larger than the magnitude of the inhibitory response. The large stimulatory reserve of the renin-angiotensin system may be one of the causes for the remarkable salt-conserving power of the mammalian kidney. Physiological stimulation of renin secretion and expression relies on the activation of regulatory pathways that converge on the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA) pathway. Mice with selective Gs-alpha (Gsα) deficiency in juxtaglomerular granular cells show a marked reduction of basal renin secretion, and an almost complete unresponsiveness of renin release to furosemide, hydralazine, or isoproterenol. Cyclooxygenase-2 generating prostaglandin E(2) (PGE(2)) and prostacyclin (PGI(2)) in MD and thick ascending limb cells is one of the main effector systems utilizing Gsα-coupled receptors to stimulate the renin-angiotensin system. In addition, β-adrenergic receptors are critical for the expression of high basal levels of renin and for its release response to lowering blood pressure or MD sodium chloride concentration. Nitric oxide generated by nitric oxide synthases in the MD and in endothelial cells enhances cAMP-dependent signaling by stabilizing cAMP through cyclic guanosine monophosphate-dependent inhibition of phosphodiesterase 3. The stimulation of renin secretion by drugs that inhibit angiotensin II formation or action results from the convergent activation of cAMP probably through indirect augmentation of the activity of PGE(2) and PGI(2) receptors, β-adrenergic receptors, and nitric oxide.
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Affiliation(s)
- Soo Mi Kim
- Department of Physiology, Chonbuk National University Medical School, Jeonju, 561-181, South Korea
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13
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Young CN, Davisson RL. In vivo assessment of neurocardiovascular regulation in the mouse: principles, progress, and prospects. Am J Physiol Heart Circ Physiol 2011; 301:H654-62. [PMID: 21705676 DOI: 10.1152/ajpheart.00355.2011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A growing body of evidence indicates that a number of common complex diseases, including hypertension, heart failure, and obesity, are characterized by alterations in central neurocardiovascular regulation. However, our understanding of how changes within the central nervous system contribute to the development and progression of these and other diseases remains unclear. As with many areas of cardiovascular research, the mouse has emerged as a key species for investigations of neuroregulatory processes because of its amenability to highly specific genetic manipulations. In parallel with the development of increasingly sophisticated murine models has come the miniaturization and advancement in methodologies for in vivo assessment of neurocardiovascular end points in the mouse. The following brief review will focus on a number of key direct and indirect experimental approaches currently in use, including measurement of arterial blood pressure, assessment of cardiovascular autonomic control, and evaluation of arterial baroreflex function. The advantages and limitations of each methodology are highlighted to allow for a critical evaluation by the reader when considering these approaches.
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Affiliation(s)
- Colin N Young
- Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853-6401, USA.
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Circadian control of mouse heart rate and blood pressure by the suprachiasmatic nuclei: behavioral effects are more significant than direct outputs. PLoS One 2010; 5:e9783. [PMID: 20339544 PMCID: PMC2842429 DOI: 10.1371/journal.pone.0009783] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 02/25/2010] [Indexed: 11/19/2022] Open
Abstract
Background Diurnal variations in the incidence of events such as heart attack and stroke suggest a role for circadian rhythms in the etiology of cardiovascular disease. The aim of this study was to assess the influence of the suprachiasmatic nucleus (SCN) circadian clock on cardiovascular function. Methodology/Principal Findings Heart rate (HR), blood pressure (BP) and locomotor activity (LA) were measured in circadian mutant (Vipr2−/−) mice and wild type littermates, using implanted radio-telemetry devices. Sleep and wakefulness were studied in similar mice implanted with electroencephalograph (EEG) electrodes. There was less diurnal variation in the frequency and duration of bouts of rest/activity and sleep/wake in Vipr2−/− mice than in wild type (WT) and short “ultradian” episodes of arousal were more prominent, especially in constant conditions (DD). Activity was an important determinant of circadian variation in BP and HR in animals of both genotypes; altered timing of episodes of activity and rest (as well as sleep and wakefulness) across the day accounted for most of the difference between Vipr2−/− mice and WT. However, there was also a modest circadian rhythm of resting HR and BP that was independent of LA. Conclusions/Significance If appropriate methods of analysis are used that take into account sleep and locomotor activity level, mice are a good model for understanding the contribution of circadian timing to cardiovascular function. Future studies of the influence of sleep and wakefulness on cardiovascular physiology may help to explain accumulating evidence linking disrupted sleep with cardiovascular disease in man.
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Abstract
Hypertension is a major risk factor for cardiovascular disease and death. The "silent" rise of blood pressure that occurs over time is largely asymptomatic. However, its impact is deafening-causing and exacerbating cardiovascular disease, end-organ damage, and death. The present article addresses recent observations from human and animal studies that provide new insights into how the circadian clock regulates blood pressure, contributes to hypertension, and ultimately evolves vascular disease. Further, the molecular components of the circadian clock and their relationship with locomotor activity, metabolic control, fluid balance, and vascular resistance are discussed with an emphasis on how these novel, circadian clock-controlled mechanisms contribute to hypertension.
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Affiliation(s)
- R Daniel Rudic
- Department of Pharmacology and Toxicology, 1120 15th St., Medical College of Georgia, Augusta, GA 30912, USA.
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Chang L, Villacorta L, Zhang J, Garcia-Barrio MT, Yang K, Hamblin M, Whitesall SE, D'Alecy LG, Chen YE. Vascular smooth muscle cell-selective peroxisome proliferator-activated receptor-gamma deletion leads to hypotension. Circulation 2009; 119:2161-9. [PMID: 19364979 DOI: 10.1161/circulationaha.108.815803] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Peroxisome proliferator-activated receptor-gamma (PPARgamma) agonists are commonly used to treat diabetes, although their PPARgamma-dependent effects transcend their role as insulin sensitizers. Thiazolidinediones lower blood pressure (BP) in diabetic patients, whereas results from conventional/tissue-specific PPARgamma experimental models suggest an important pleiotropic role for PPARgamma in BP control. Little evidence is available on the molecular mechanisms underlying the role of vascular smooth muscle cell-specific PPARgamma in basal vascular tone. METHODS AND RESULTS We show that vascular smooth muscle cell-selective deletion of PPARgamma impairs vasoactivity with an overall reduction in BP. Aortic contraction in response to norepinephrine is reduced and vasorelaxation is enhanced in response to beta-adrenergic receptor (beta-AdR) agonists in vitro. Similarly, vascular smooth muscle cell-selective PPARgamma knockout mice display a biphasic response to norepinephrine in BP, reversible on administration of beta-AdR blocker, and enhanced BP reduction on treatment with beta-AdR agonists. Consistent with enhanced beta2-AdR responsiveness, we found that the absence of PPARgamma in vascular smooth muscle cells increased beta2-AdR expression, possibly leading to the hypotensive phenotype during the rest phase. CONCLUSIONS These data uncovered the beta2-AdR as a novel target of PPARgamma transcriptional repression in vascular smooth muscle cells and indicate that PPARgamma regulation of beta2-adrenergic signaling is important in the modulation of BP.
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Affiliation(s)
- Lin Chang
- Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI 48105, USA
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Wang N, Yang G, Jia Z, Zhang H, Aoyagi T, Soodvilai S, Symons JD, Schnermann JB, Gonzalez FJ, Litwin SE, Yang T. Vascular PPARgamma controls circadian variation in blood pressure and heart rate through Bmal1. Cell Metab 2008; 8:482-91. [PMID: 19041764 PMCID: PMC5484540 DOI: 10.1016/j.cmet.2008.10.009] [Citation(s) in RCA: 186] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2008] [Revised: 09/22/2008] [Accepted: 10/22/2008] [Indexed: 11/25/2022]
Abstract
Thiazolidinediones (TZDs) are PPARgamma activators that exhibit vasculoprotective properties. To determine the vascular function of PPARgamma, we analyzed Tie2Cre/flox and SM22Cre/flox mice. Unexpectedly, both knockout strains exhibited a significant reduction of circadian variations in blood pressure and heart rate in parallel with diminished variations in urinary norepinephrine/epinephrine excretion and impaired rhythmicity of the canonical clock genes, including Bmal1. PPARgamma expression in the aorta exhibited a robust rhythmicity with a more than 20-fold change during the light/dark cycle. Rosiglitazone treatment induced aortic expression of Bmal1 mRNA, and ChIP and promoter assays revealed that Bmal1 is a direct PPARgamma target gene. These studies have uncovered a role for vascular PPARgamma as a peripheral factor participating in regulation of cardiovascular rhythms.
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Affiliation(s)
- Ningning Wang
- Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Guangrui Yang
- Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Zhanjun Jia
- Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Hui Zhang
- Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Toshinori Aoyagi
- Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Sunhapas Soodvilai
- Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, Utah
| | - J. David Symons
- College of Health, University of Utah, Salt Lake City, Utah
- Division of Endocrinology, Metabolism and Diabetes, University of Utah, Salt Lake City, Utah
| | - Jurgen B. Schnermann
- National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, Maryland
| | | | - Sheldon E. Litwin
- Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Tianxin Yang
- Department of Internal Medicine, University of Utah and Salt Lake Veterans Affairs Medical Center, Salt Lake City, Utah
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Kim SM, Eisner C, Faulhaber-Walter R, Mizel D, Wall SM, Briggs JP, Schnermann J. Salt sensitivity of blood pressure in NKCC1-deficient mice. Am J Physiol Renal Physiol 2008; 295:F1230-8. [PMID: 18701622 DOI: 10.1152/ajprenal.90392.2008] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
NKCC1 is a widely expressed isoform of the Na-2Cl-K cotransporter that mediates several direct and indirect vascular effects and regulates expression and release of renin. In this study, we used NKCC1-deficient (NKCC1-/-) and wild-type (WT) mice to assess day/night differences of blood pressure (BP), locomotor activity, and renin release and to study the effects of high (8%) or low (0.03%) dietary NaCl intake on BP, activity, and the renin/aldosterone system. On a standard diet, 24-h mean arterial blood pressure (MAP) and heart rate determined by radiotelemetry, and their day/night differences, were not different in NKCC1-/- and WT mice. Spontaneous and wheel-running activities in the active night phase were lower in NKCC1-/- than WT mice. In NKCC1-/- mice on a high-NaCl diet, MAP increased by 10 mmHg in the night without changes in heart rate. In contrast, there was no salt-dependent blood pressure change in WT mice. MAP reductions by hydralazine (1 mg/kg) or isoproterenol (10 microg/mouse) were significantly greater in NKCC1-/- than WT mice. Plasma renin (PRC; ng ANG I.ml(-1).h(-1)) and aldosterone (aldo; pg/ml) concentrations were higher in NKCC1-/- than WT mice (PRC: 3,745+/-377 vs. 1,245+/-364; aldo: 763+/-136 vs. 327+/-98). Hyperreninism and hyperaldosteronism were found in NKCC1-/- mice during both day and night. High Na suppressed PRC and aldosterone in both NKCC1-/- and WT mice, whereas a low-Na diet increased PRC and aldosterone in WT but not NKCC1-/- mice. We conclude that 24-h MAP and MAP circadian rhythms do not differ between NKCC1-/- and WT mice on a standard diet, probably reflecting a balance between anti- and prohypertensive factors, but that blood pressure of NKCC1-/- mice is more sensitive to increases and decreases of Na intake.
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Affiliation(s)
- Soo Mi Kim
- National Institute of Digestive and Diabetes and Kidney Diseases, National Institutes of Health, 10 Center Dr.-MSC 1370, Bethesda, MD 20892, USA
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