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Bhagavan H, Wei AD, Oliveira LM, Aldinger KA, Ramirez JM. Chronic intermittent hypoxia elicits distinct transcriptomic responses among neurons and oligodendrocytes within the brainstem of mice. Am J Physiol Lung Cell Mol Physiol 2024; 326:L698-L712. [PMID: 38591125 DOI: 10.1152/ajplung.00320.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 01/22/2024] [Accepted: 03/26/2024] [Indexed: 04/10/2024] Open
Abstract
Chronic intermittent hypoxia (CIH) is a prevalent condition characterized by recurrent episodes of oxygen deprivation, linked to respiratory and neurological disorders. Prolonged CIH is known to have adverse effects, including endothelial dysfunction, chronic inflammation, oxidative stress, and impaired neuronal function. These factors can contribute to serious comorbidities, including metabolic disorders and cardiovascular diseases. To investigate the molecular impact of CIH, we examined male C57BL/6J mice exposed to CIH for 21 days, comparing with normoxic controls. We used single-nucleus RNA sequencing to comprehensively examine the transcriptomic impact of CIH on key cell classes within the brainstem, specifically excitatory neurons, inhibitory neurons, and oligodendrocytes. These cell classes regulate essential physiological functions, including autonomic tone, cardiovascular control, and respiration. Through analysis of 10,995 nuclei isolated from pontine-medullary tissue, we identified seven major cell classes, further subdivided into 24 clusters. Our findings among these cell classes, revealed significant differential gene expression, underscoring their distinct responses to CIH. Notably, neurons exhibited transcriptional dysregulation of genes associated with synaptic transmission, and structural remodeling. In addition, we found dysregulated genes encoding ion channels and inflammatory response. Concurrently, oligodendrocytes exhibited dysregulated genes associated with oxidative phosphorylation and oxidative stress. Utilizing CellChat network analysis, we uncovered CIH-dependent altered patterns of diffusible intercellular signaling. These insights offer a comprehensive transcriptomic cellular atlas of the pons-medulla and provide a fundamental resource for the analysis of molecular adaptations triggered by CIH.NEW & NOTEWORTHY This study on chronic intermittent hypoxia (CIH) from pons-medulla provides initial insights into the molecular effects on excitatory neurons, inhibitory neurons, and oligodendrocytes, highlighting our unbiased approach, in comparison with earlier studies focusing on single target genes. Our findings reveal that CIH affects cell classes distinctly, and the dysregulated genes in distinct cell classes are associated with synaptic transmission, ion channels, inflammation, oxidative stress, and intercellular signaling, advancing our understanding of CIH-induced molecular responses.
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Affiliation(s)
- Hemalatha Bhagavan
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, United States
| | - Aguan D Wei
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, United States
| | - Luiz M Oliveira
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, United States
| | - Kimberly A Aldinger
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, United States
- Department of Pediatrics, University of Washington, Seattle, Washington, United States
- Department of Neurology, University of Washington, Seattle, Washington, United States
| | - Jan-Marino Ramirez
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, United States
- Department of Pediatrics, University of Washington, Seattle, Washington, United States
- Department of Neurological Surgery, University of Washington, Seattle, Washington, United States
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Arnaud C, Billoir E, de Melo Junior AF, Pereira SA, O'Halloran KD, Monteiro EC. Chronic intermittent hypoxia-induced cardiovascular and renal dysfunction: from adaptation to maladaptation. J Physiol 2023; 601:5553-5577. [PMID: 37882783 DOI: 10.1113/jp284166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 10/12/2023] [Indexed: 10/27/2023] Open
Abstract
Chronic intermittent hypoxia (CIH) is the dominant pathological feature of human obstructive sleep apnoea (OSA), which is highly prevalent and associated with cardiovascular and renal diseases. CIH causes hypertension, centred on sympathetic nervous overactivity, which persists following removal of the CIH stimulus. Molecular mechanisms contributing to CIH-induced hypertension have been carefully delineated. However, there is a dearth of knowledge on the efficacy of interventions to ameliorate high blood pressure in established disease. CIH causes endothelial dysfunction, aberrant structural remodelling of vessels and accelerates atherosclerotic processes. Pro-inflammatory and pro-oxidant pathways converge on disrupted nitric oxide signalling driving vascular dysfunction. In addition, CIH has adverse effects on the myocardium, manifesting atrial fibrillation, and cardiac remodelling progressing to contractile dysfunction. Sympatho-vagal imbalance, oxidative stress, inflammation, dysregulated HIF-1α transcriptional responses and resultant pro-apoptotic ER stress, calcium dysregulation, and mitochondrial dysfunction conspire to drive myocardial injury and failure. CIH elaborates direct and indirect effects in the kidney that initially contribute to the development of hypertension and later to chronic kidney disease. CIH-induced morphological damage of the kidney is dependent on TLR4/NF-κB/NLRP3/caspase-1 inflammasome activation and associated pyroptosis. Emerging potential therapies related to the gut-kidney axis and blockade of aryl hydrocarbon receptors (AhR) are promising. Cardiorenal outcomes in response to intermittent hypoxia present along a continuum from adaptation to maladaptation and are dependent on the intensity and duration of exposure to intermittent hypoxia. This heterogeneity of OSA is relevant to therapeutic treatment options and we argue the need for better stratification of OSA phenotypes.
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Affiliation(s)
- Claire Arnaud
- Université Grenoble-Alpes INSERM U1300, Laboratoire HP2, Grenoble, France
| | - Emma Billoir
- Université Grenoble-Alpes INSERM U1300, Laboratoire HP2, Grenoble, France
| | | | - Sofia A Pereira
- iNOVA4Health, NOVA Medical School, Universidade NOVA de Lisboa, Lisboa, Portugal
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - Emilia C Monteiro
- iNOVA4Health, NOVA Medical School, Universidade NOVA de Lisboa, Lisboa, Portugal
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3
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Zhang Z, Kalra H, Delzell MC, Jedlicka CR, Vasilyev M, Vasileva A, Tomasson MH, Bates ML. CORP: Sources and degrees of variability in whole animal intermittent hypoxia experiments. J Appl Physiol (1985) 2023; 134:1207-1215. [PMID: 36958346 PMCID: PMC10151045 DOI: 10.1152/japplphysiol.00643.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 02/17/2023] [Accepted: 03/12/2023] [Indexed: 03/25/2023] Open
Abstract
Chamber exposures are commonly used to evaluate the physiological and pathophysiological consequences of intermittent hypoxia in animal models. Researchers in this field use both commercial and custom-built chambers in their experiments. The purpose of this Cores of Reproducibility in Physiology paper is to demonstrate potential sources of variability in these systems that researchers should consider. Evaluating the relationship between arterial oxygen saturation and inspired oxygen concentration, we found that there are important sex-dependent differences in the commonly used C57BL6/J mouse model. The time delay of the oxygen sensor that provides feedback to the system during the ramp-down and ramp-up phases was different, limiting the number of cycles per hour that can be conducted and the overall stability of the oxygen concentration. The time to reach the hypoxic and normoxic hold stages, and the overall oxygen concentration, were impacted by the cycle number. These variables were further impacted by whether there are animals present in the chamber, highlighting the importance of verifying the cycling frequency with animals in the chamber. At ≤14 cycles/h, instability in the chamber oxygen concentration did not impact arterial oxygen saturation but may be important at higher cycle numbers. Taken together, these data demonstrate the important sources of variability that justify reporting and verifying the target oxygen concentration, cycling frequency, and arterial oxygen concentration, particularly when comparing different animal models and chamber configurations.NEW & NOTEWORTHY Intermittent hypoxia exposures are commonly used in physiology and many investigators use chamber systems to perform these studies. Because of the variety of chamber systems and protocols used, it is important to understand the sources of variability in intermittent hypoxia experiments that can impact reproducibility. We demonstrate sources of variability that come from the animal model, the intermittent hypoxia protocol, and the chamber system that can impact reproducibility.
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Affiliation(s)
- Zishan Zhang
- Interdisciplinary Graduate Program in Molecular Medicine, University of Iowa, Iowa City, Iowa, United States
- Division of Hematology, Oncology, and Bone Marrow Transplantation, Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Hardik Kalra
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa, United States
| | - Matthew C Delzell
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa, United States
- Kirksville College of Osteopathic Medicine, A.T. Still University, Kirksville, Missouri, United States
| | - Charles R Jedlicka
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa, United States
| | - Mikhail Vasilyev
- Division of Hematology, Oncology, and Bone Marrow Transplantation, Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Anastasiia Vasileva
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa, United States
| | - Michael H Tomasson
- Interdisciplinary Graduate Program in Molecular Medicine, University of Iowa, Iowa City, Iowa, United States
- Division of Hematology, Oncology, and Bone Marrow Transplantation, Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa, United States
| | - Melissa L Bates
- Interdisciplinary Graduate Program in Molecular Medicine, University of Iowa, Iowa City, Iowa, United States
- Division of Hematology, Oncology, and Bone Marrow Transplantation, Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa, United States
- Division of Neonatology, Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States
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L-Citrulline Supplementation Reduces Blood Pressure and Myocardial Infarct Size under Chronic Intermittent Hypoxia, a Major Feature of Sleep Apnea Syndrome. Antioxidants (Basel) 2022; 11:antiox11122326. [PMID: 36552534 PMCID: PMC9774116 DOI: 10.3390/antiox11122326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 11/14/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022] Open
Abstract
Intermittent hypoxia (IH) is a landmark of obstructive sleep apnea (OSA) at the core of the cardiovascular consequences of OSA. IH triggers oxidative stress, a major underlying mechanism for elevated blood pressure (BP) and increased infarct size. L-citrulline is an amino acid that has been demonstrated to be protective of the cardiovascular system and exert pleiotropic effects. Therefore, we tested the impact of citrulline supplementation on IH-induced increase in BP and infarct size. Four groups of rats exposed to normoxia (N) or IH [14 days (d), 8 h/day, 30 s-O2 21%/30 s-O2 5%] and were supplemented or not with citrulline (1 g·kg-1·d-1). After 14 d, BP was measured, and hearts were submitted to global ischemia-reperfusion to measure infarct size. Histological and biochemical analyses were conducted on hearts and aorta to assess oxidative stress. Citrulline significantly reduced BP (-9.92%) and infarct size (-18.22%) under IH only. In the aorta, citrulline supplementation significantly decreased superoxide anion and nitrotyrosine levels under IH and abolished the IH-induced decrease in nitrite. Citrulline supplementation significantly decreased myocardial superoxide anion levels and xanthine oxidase enzyme activity under IH. Citrulline shows a cardioprotective capacity by limiting IH-induced pro-oxidant activity. Our results suggest that citrulline might represent a new pharmacological strategy in OSA patients with high cardiovascular risk.
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Zhang J, Xie B, Tang Y, Zhou B, Wang Q, Ge Q, Zhou Y, Gu T. Downregulation of miR-34c-5p alleviates chronic intermittent hypoxia-induced myocardial damage by targeting sirtuin 1. J Biochem Mol Toxicol 2022; 36:e23164. [PMID: 35848756 DOI: 10.1002/jbt.23164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 05/28/2022] [Accepted: 07/01/2022] [Indexed: 11/09/2022]
Abstract
Numerous microRNAs (miRs) are abnormally expressed in response to hypoxia-induced myocardial damage. Herein, miR-34c-5p as a potential pharmaco-target was investigated in a mouse model of chronic intermittent hypoxia (CIH)-induced myocardial damage. A mouse model of myocardial damage was established using CIH with 7% or 21% O2 alternating 60 s for 12 h/day, 21% O2 for 12 h/day. AntagomiR-34c-5p (20 nM/0.1 ml; once a week for 12 weeks) was used as a miR-34c-5p inhibitor in a mouse model with tail-vein injection. In another experiment, mice were administrated with Sirt1 activator SRT1720 (50 mg/kg/day) by intraperitoneal injection. Gene Expression Omnibus database showed a significant upregulation of miR-34c-5p expression in the ischemic myocardium of male mice. In CIH-stimulated mice, miR-34c-5p expression was also significantly increased compared with normal mice. Treatment of antagomiR-34c-5p significantly restrained CIH-triggered myocardial apoptosis. After administration of antagomiR-34c-5p or Sirt1 activator SRT1720, cardiac hypertrophy and oxidative stress were attenuated in CIH-stimulated mice. We also found sirtuin 1 (Sirt1) as a direct target of miR-34c-5p, which was able to mediate Sirt1 protein expression in cardiomyocytes. AntagomiR-34c-5p injection markedly elevated Sirt1 protein expression in CIH-stimulated mice. AntagomiR-34c-5p or Sirt1 activator SRT1720 administration exhibited the antioxidative activity and cardioprotective roles in CIH-stimulated mice.
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Affiliation(s)
- Jun Zhang
- Department of Cardiology, Chengdu First People's Hospital, Chengdu, Sichuan, China
| | - Bo Xie
- Department of Cardiology, Chengdu First People's Hospital, Chengdu, Sichuan, China
| | - Yanrong Tang
- Department of Cardiology, Chengdu First People's Hospital, Chengdu, Sichuan, China
| | - Bo Zhou
- Department of Cardiology, Chengdu First People's Hospital, Chengdu, Sichuan, China
| | - Qiong Wang
- Department of Cardiology, Chengdu First People's Hospital, Chengdu, Sichuan, China
| | - Qing Ge
- Department of Cardiology, Chengdu First People's Hospital, Chengdu, Sichuan, China
| | - Yufei Zhou
- Department of Cardiology, Chengdu First People's Hospital, Chengdu, Sichuan, China
| | - Tongqing Gu
- School of Foreign Languages, Chengdu University of Information Technology, Chengdu, Sichuan, China
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Drummond SE, Burns DP, O'Connor KM, Clarke G, O'Halloran KD. The role of NADPH oxidase in chronic intermittent hypoxia-induced respiratory plasticity in adult male mice. Respir Physiol Neurobiol 2021; 292:103713. [PMID: 34116239 DOI: 10.1016/j.resp.2021.103713] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/18/2021] [Accepted: 06/06/2021] [Indexed: 10/21/2022]
Abstract
Reactive oxygen species (ROS) are proposed as mediators of chronic intermittent hypoxia (CIH)-induced respiratory plasticity. We sought to determine if NADPH oxidase 2 (NOX2)-derived ROS underpin CIH-induced maladaptive changes in respiratory control. Adult male mice (C57BL/6 J) were assigned to one of three groups: normoxic controls (sham); chronic intermittent hypoxia-exposed (CIH, 12 cycles/hour, 8 h/day for 14 days); and CIH + apocynin (NOX2 inhibitor, 2 mM) given in the drinking water throughout exposure to CIH. In addition, we studied sham and CIH-exposed NOX2-null mice (B6.129S-CybbTM1Din/J). Whole-body plethysmography was used to measure breathing and metabolic parameters. Ventilation (V̇I/V̇CO2) during normoxia was unaffected by CIH, but apnoea index was increased, which was prevented by apocynin, but not by NOX2 deletion. The ventilatory response to hypercapnia following exposure to CIH was potentiated in NOX2-null mice. Our results reveal ROS-dependent influences on the control of breathing and point to antioxidant intervention as a potential adjunctive therapeutic strategy in respiratory control disorders.
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Affiliation(s)
- Sarah E Drummond
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - David P Burns
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - Karen M O'Connor
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland; APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Anatomy & Neuroscience, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - Gerard Clarke
- APC Microbiome Ireland, University College Cork, Cork, Ireland; Department of Psychiatry and Neurobehavioural Science, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland
| | - Ken D O'Halloran
- Department of Physiology, School of Medicine, College of Medicine & Health, University College Cork, Cork, Ireland; APC Microbiome Ireland, University College Cork, Cork, Ireland.
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de Oliveira Y, Cavalcante RGS, Cavalcanti Neto MP, Magnani M, Braga VDA, de Souza EL, de Brito Alves JL. Oral administration of Lactobacillus fermentum post-weaning improves the lipid profile and autonomic dysfunction in rat offspring exposed to maternal dyslipidemia. Food Funct 2021; 11:5581-5594. [PMID: 32524104 DOI: 10.1039/d0fo00514b] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Maternal dyslipidemia alters the gut microbiota composition and contributes to the development of arterial hypertension (AH) in offspring. Here, we evaluated the effects of a new Lactobacillus fermentum probiotic formulation given post-weaning on cardiometabolic parameters and gut microbiota in male and female rat offspring from dams exposed to maternal dyslipidemia during pregnancy and lactation. METHODS Wistar rats (n = 14) were fed with a control diet (CTL = 7) or a dyslipidemic diet (DLP = 7) during pregnancy and lactation. After weaning, male and female offspring received a standard diet up to 90 days of life. Rats were allocated into three groups: CTL group + saline solution (n = 14); DLP group + saline solution (n = 14) and DLP group receiving a probiotic cocktail (n = 14). A vehicle or probiotic formulation containing L. fermentum 139, L. fermentum 263 and L. fermentum 296 (ratio 1 : 1 : 1, 1 × 109 CFU mL-1) was administered daily by oral gavage for 8 weeks. RESULTS The intervention with the probiotic formulation of L. fermentum in male and female offspring reduced total cholesterol (TC) and increased HDL-c, but did not affect the insulin resistance induced by maternal dyslipidemia. Additionally, the male and female rats that received the probiotic formulation of L. fermentum demonstrated improvement in fecal Lactobacillus sp. counts, blood pressure and sympathetic tone, without affecting baroreflex modulation. CONCLUSION The probiotic formulation containing L. fermentum improved the lipid profile and autonomic dysfunction in male and female offspring exposed to maternal dyslipidemia.
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Affiliation(s)
- Yohanna de Oliveira
- Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa, Brazil.
| | | | | | - Marciane Magnani
- Department of Food Engineering, Technology Center, Federal University of Paraíba, Joao Pessoa, Brazil
| | - Valdir de Andrade Braga
- Department of Biotechnology, Biotechnology Center, Federal University of Paraíba, João Pessoa, Brazil and Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - Evandro Leite de Souza
- Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa, Brazil.
| | - José Luiz de Brito Alves
- Department of Nutrition, Health Sciences Center, Federal University of Paraíba, João Pessoa, Brazil.
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Alzahrani AA, Cao LL, Aldossary HS, Nathanael D, Fu J, Ray CJ, Brain KL, Kumar P, Coney AM, Holmes AP. β-Adrenoceptor blockade prevents carotid body hyperactivity and elevated vascular sympathetic nerve density induced by chronic intermittent hypoxia. Pflugers Arch 2021; 473:37-51. [PMID: 33210151 PMCID: PMC7782391 DOI: 10.1007/s00424-020-02492-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 10/26/2020] [Accepted: 11/06/2020] [Indexed: 12/17/2022]
Abstract
Carotid body (CB) hyperactivity promotes hypertension in response to chronic intermittent hypoxia (CIH). The plasma concentration of adrenaline is reported to be elevated in CIH and our previous work suggests that adrenaline directly activates the CB. However, a role for chronic adrenergic stimulation in mediating CB hyperactivity is currently unknown. This study evaluated whether beta-blocker treatment with propranolol (Prop) prevented the development of CB hyperactivity, vascular sympathetic nerve growth and hypertension caused by CIH. Adult male Wistar rats were assigned into 1 of 4 groups: Control (N), N + Prop, CIH and CIH + Prop. The CIH paradigm consisted of 8 cycles h-1, 8 h day-1, for 3 weeks. Propranolol was administered via drinking water to achieve a dose of 40 mg kg-1 day-1. Immunohistochemistry revealed the presence of both β1 and β2-adrenoceptor subtypes on the CB type I cell. CIH caused a 2-3-fold elevation in basal CB single-fibre chemoafferent activity and this was prevented by chronic propranolol treatment. Chemoafferent responses to hypoxia and mitochondrial inhibitors were attenuated by propranolol, an effect that was greater in CIH animals. Propranolol decreased respiratory frequency in normoxia and hypoxia in N and CIH. Propranolol also abolished the CIH mediated increase in vascular sympathetic nerve density. Arterial blood pressure was reduced in propranolol groups during hypoxia. Propranolol exaggerated the fall in blood pressure in most (6/7) CIH animals during hypoxia, suggestive of reduced sympathetic tone. These findings therefore identify new roles for β-adrenergic stimulation in evoking CB hyperactivity, sympathetic vascular hyperinnervation and altered blood pressure control in response to CIH.
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Affiliation(s)
- Abdulaziz A Alzahrani
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Respiratory Care Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Lily L Cao
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Institute of Cardiovascular Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Hayyaf S Aldossary
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- College of Medicine, Basic Medical Sciences, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Demitris Nathanael
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Jiarong Fu
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Clare J Ray
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Keith L Brain
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
- Institute of Cardiovascular Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Prem Kumar
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Andrew M Coney
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
| | - Andrew P Holmes
- Institute of Clinical Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
- Institute of Cardiovascular Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
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9
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Xu L, Yang Y, Chen J. The role of reactive oxygen species in cognitive impairment associated with sleep apnea. Exp Ther Med 2020; 20:4. [PMID: 32934669 PMCID: PMC7471880 DOI: 10.3892/etm.2020.9132] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 02/07/2020] [Indexed: 02/07/2023] Open
Abstract
Obstructive sleep apnea (OSA), a common breathing and sleeping disorder, is associated with a broad range of neurocognitive difficulties. Intermittent hypoxia (IH), one major characteristic of OSA, has been shown to impair learning and memory due to increased levels of reactive oxygen species (ROS). Under normal conditions, ROS are produced in low concentrations and act as signaling molecules in different processes. However, IH treatment leads to elevated ROS production via multiple pathways, including mitochondrial electron transport chain dysfunction and in particular complex I dysfunction, and induces oxidative tissue damage. Moreover, elevated ROS results in the accumulation of unfolded or misfolded proteins in the endoplasmic reticulum (ER) and increased activity of peroxisomes, such as NADPH oxidase, xanthine oxidase and phospholipase A2. Furthermore, oxidative tissue damage has been found in regions of the brains of patients with OSA, including the cortex and hippocampus, which are associated with memory and executive function. Furthermore, increased ROS levels in these regions of the brain induce damage via inflammation, apoptosis, ER stress and neuronal activity disturbance. The present review focuses on the mechanism of excessive ROS production in an OSA model and the relationship between ROS and cognitive impairment.
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Affiliation(s)
- Linhao Xu
- Department of Cardiology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, P.R. China.,Department of Pathology, School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang 310053, P.R. China.,Translational Medicine Research Center, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310006, P.R. China
| | - Yibo Yang
- College of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 201424, P.R. China
| | - Jian Chen
- Department of Pathology, School of Basic Medical Sciences and Forensic Medicine, Hangzhou Medical College, Hangzhou, Zhejiang 310053, P.R. China
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Villasana-Salazar B, Hernández-Soto R, Guerrero-Gómez ME, Ordaz B, Manrique-Maldonado G, Salgado-Puga K, Peña-Ortega F. Chronic intermittent hypoxia transiently increases hippocampal network activity in the gamma frequency band and 4-Aminopyridine-induced hyperexcitability in vitro. Epilepsy Res 2020; 166:106375. [PMID: 32745888 DOI: 10.1016/j.eplepsyres.2020.106375] [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: 12/02/2019] [Revised: 04/21/2020] [Accepted: 05/28/2020] [Indexed: 12/12/2022]
Abstract
Chronic intermittent hypoxia (CIH) is the most distinct feature of obstructive sleep apnea (OSA), a common breathing and sleep disorder that leads to several neuropathological consequences, including alterations in the hippocampal network and in seizure susceptibility. However, it is currently unknown whether these alterations are permanent or remit upon normal oxygenation. Here, we investigated the effects of CIH on hippocampal spontaneous network activity and hyperexcitability in vitro and explored whether these alterations endure or fade after normal oxygenation. Results showed that applying CIH for 21 days to adult rats increases gamma-band hippocampal network activity and aggravates 4-Aminopyridine-induced epileptiform activity in vitro. Interestingly, these CIH-induced alterations remit after 30 days of normal oxygenation. Our findings indicate that hippocampal network alterations and increased seizure susceptibility induced by CIH are not permanent and can be spontaneously reverted, suggesting that therapeutic interventions against OSA in patients with epilepsy, such as surgery or continuous positive airway pressure (CPAP), could be favorable for seizure control.
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Affiliation(s)
- Benjamín Villasana-Salazar
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, QRO 76230, México
| | - Rebeca Hernández-Soto
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, QRO 76230, México
| | - María Estefanía Guerrero-Gómez
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, QRO 76230, México
| | - Benito Ordaz
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, QRO 76230, México
| | - Guadalupe Manrique-Maldonado
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, QRO 76230, México
| | - Karla Salgado-Puga
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, QRO 76230, México
| | - Fernando Peña-Ortega
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, QRO 76230, México.
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11
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Bates ML, Gundry RL, Lindsey ML. Using an Investigative Journalism Approach to Design Mechanistic Experiments in Physiology. Physiology (Bethesda) 2020; 35:218-219. [PMID: 32490747 DOI: 10.1152/physiol.00006.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
| | | | - Merry L Lindsey
- University of Nebraska Medical Center, Omaha, Nebraska.,Nebraska-Western Iowa Health Care System, Omaha, Nebraska
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12
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Lin ZP, Lin HL, Yu XP, Zheng YJ, Cheng SY. TLR4 mediates inflammation and hepatic fibrosis induced by chronic intermittent hypoxia in rats. Mol Med Rep 2020; 22:651-660. [PMID: 32626927 PMCID: PMC7339543 DOI: 10.3892/mmr.2020.11134] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 03/05/2020] [Indexed: 12/24/2022] Open
Abstract
Obstructive sleep apnea syndrome (OSAS) is a common and complex disorder that is associated with liver injury. Moreover, previous studies have revealed that chronic intermittent hypoxia (CIH) is associated with the development of non-alcoholic fatty liver disease and hepatic fibrosis. However, the underlying molecular mechanisms remain largely unknown. The present study aimed to investigate whether chronic intermittent hypoxia induced hepatic fibrosis, in addition to determining its underlying mechanisms, in CIH model rats using immunohistochemistry, western blotting and reverse transcription-quantitative PCR. The present results suggested that CIH caused hepatic fibrosis and increased the expression levels of interleukin (IL)-1β, IL-8, monocyte chemotactic-1, tumor necrosis factor-α, intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in the liver; these conditions could be reversed by Toll-like receptor 4 (TLR4) short hairpin RNA lentivirus treatment. Moreover, immunohistochemistry and western blotting results indicated that TLR4 and NF-κB expression levels were significantly increased in the CIH and CIH-TLR4 empty vector lentivirus group. However, protein expression levels of TLR4, NF-κB, inhibitor of NF-κB and phosphorylated-mitogen-activated protein kinase (MAPK)-1 in the hypoxia/reoxygenation group were significantly higher compared with the control group (P<0.05), and these results were reversed by the MAPK inhibitor U0126 in vitro. Collectively, the present preliminary results suggested that inflammation and the TLR4/NF-κB/MAPK signaling pathway may be involved in CIH-induced liver fibrosis.
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Affiliation(s)
- Zhi-Peng Lin
- Department of Infectious Diseases, The First Quanzhou Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian 362000, P.R. China
| | - Hui-Li Lin
- Department of Cardiology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian 362000, P.R. China
| | - Xue-Ping Yu
- Department of Infectious Diseases, The First Quanzhou Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian 362000, P.R. China
| | - Yi-Juan Zheng
- Department of Infectious Diseases, The First Quanzhou Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian 362000, P.R. China
| | - Si-Yu Cheng
- Department of Infectious Diseases, The First Quanzhou Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian 362000, P.R. China
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13
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Clarke A, Ladha C, Wright A, Pattinson K. Losartan may attenuate altitude-related sleep disturbance. BMJ Mil Health 2020; 167:424-428. [PMID: 32086272 DOI: 10.1136/jramc-2019-001308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 11/12/2019] [Accepted: 11/15/2019] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Sleep disturbance is common at high altitude and likely driven by an exaggerated peripheral chemoreceptor response which leads to apnoeic episodes and arousal. We hypothesised that this heightened response is in part mediated through angiotensin II receptors in the carotid body. To examine this link, we studied the effect of angiotensin II receptor blocker on sleep disturbance. METHODS Twenty participants paired by age, gender and ACE phenotype ascended to the Whymper Hut (5000 m) on Chimborazo in the Ecuadorean Andes as part of a double-blinded randomised placebo-controlled study of physiological mechanisms. Subjects were randomised to either losartan 100 mg daily or placebo. The primary outcome of sleep efficiency was measured using wrist-mounted actigraphs. One pair was excluded from analysis after descending before the end of the study due to acute mountain sickness. RESULTS There was a significantly different response to altitude between the two groups (F=3.274, p=0.029), as a decline in sleep efficiency in the placebo group (F=10.259, p<0.001) was not replicated in the angiotensin II receptor blocker group (F=0.459, p=0.713). CONCLUSION The absence of any significant sleep disturbance in the intervention group suggests that peripheral chemoreceptor hypersensitivity is largely mediated by angiotensin II receptor activation. However, further research is needed to confirm our findings and to study the potential mechanisms of action.
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Affiliation(s)
- Alexander Clarke
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, Tyne and Wear, UK
| | - C Ladha
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, Tyne and Wear, UK
| | - A Wright
- College of Medical and Dental Sciences, University of Birmingham, Birmingham, Birmingham, UK
| | - K Pattinson
- Nuffield Department of Clinical Neurosciences, Oxford University, Oxford, Oxfordshire, UK
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14
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Dereli AS, Yaseen Z, Carrive P, Kumar NN. Adaptation of Respiratory-Related Brain Regions to Long-Term Hypercapnia: Focus on Neuropeptides in the RTN. Front Neurosci 2019; 13:1343. [PMID: 31920508 PMCID: PMC6923677 DOI: 10.3389/fnins.2019.01343] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 11/28/2019] [Indexed: 12/21/2022] Open
Abstract
Long-term hypercapnia is associated with respiratory conditions including obstructive sleep apnea, chronic obstructive pulmonary disease and obesity hypoventilation syndrome. Animal studies have demonstrated an initial (within hours) increase in ventilatory drive followed by a decrease in this response over the long-term (days–weeks) in response hypercapnia. Little is known about whether changes in the central respiratory chemoreflex are involved. Here we investigated whether central respiratory chemoreceptor neurons of the retrotrapezoid nucleus (RTN), which project to the respiratory pattern generator within the ventral respiratory column (VRC) have a role in the mechanism of neuroplasticity associated with long-term hypercapnia. Adult male C57BL/6 mice (n = 5/group) were used. Our aims were (1) to determine if galanin, neuromedin B and gastrin-releasing peptide gene expression is altered in the RTN after long-term hypercapnia. This was achieved using qPCR to measure mRNA expression changes of neuropeptides in the RTN after short-term hypercapnia (6 or 8 h, 5 or 8% CO2) or long-term hypercapnia exposure (10 day, 5 or 8% CO2), (2) in the mouse brainstem, to determine the distribution of preprogalanin in chemoreceptors, and the co-occurrence of the galanin receptor 1 (GalR1:Gi-coupled receptor) with inhibitory GlyT2 ventral respiratory column neurons using in situ hybridization (ISH) to better characterize galaninergic RTN-VRC circuitry, (3) to investigate whether long-term hypercapnia causes changes to recruitment (detected by cFos immunohistochemistry) of respiratory related neural populations including the RTN neurons and their galaninergic subset, in vivo. Collectively, we found that hypercapnia decreases neuropeptide expression in the RTN in the short-term and has the opposite effect over the long-term. Following long term hypercapnia, the number of RTN galanin neurons remains unchanged, and their responsiveness to acute chemoreflex is sustained; in contrast, we identified multiple respiratory related sites that exhibit blunted chemoreflex activation. GalR1 was distributed in 11% of preBötC and 30% of BötC glycinergic neurons. Our working hypothesis is that during long-term hypercapnia, galanin co-release from RTN neurons may counterbalance glutamatergic inputs to respiratory centers to downscale energetically wasteful hyperventilation, thereby having a role in neuroplasticity by contributing to a decrease in ventilation, through the inhibitory effects of galanin.
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Affiliation(s)
- Ayse Sumeyra Dereli
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Zarwa Yaseen
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Pascal Carrive
- Department of Anatomy, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Natasha N Kumar
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
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15
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de Araújo EV, Carneiro dos Santos LA, Speretta GFF, Ferreira GDAH, de Luna Freire MO, de Santana DF, Carvalho‐Galvão A, Cruz JC, Costa-Silva JHD, Braga V, Brito Alves JL. Short‐ and long‐term effects of maternal dyslipidaemia on blood pressure and baroreflex sensitivity in male rat offspring. Clin Exp Pharmacol Physiol 2019; 47:27-37. [DOI: 10.1111/1440-1681.13174] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 08/28/2019] [Accepted: 09/05/2019] [Indexed: 02/06/2023]
Affiliation(s)
| | | | - Guilherme Fleury Fina Speretta
- Department of Physiological Sciences Biological Sciences Centre Federal University of Santa Catarina (UFSC) Florianopolis Brazil
| | | | | | - David Filipe de Santana
- Department of Physical Education and Sport Sciences Federal University of Pernambuco Vitória de Santo Antão Brazil
| | - Alynne Carvalho‐Galvão
- Biotechnology Department Biotechnology Centre Federal University of Paraíba João Pessoa Brazil
| | - Josiane Campos Cruz
- Biotechnology Department Biotechnology Centre Federal University of Paraíba João Pessoa Brazil
| | - João Henrique da Costa-Silva
- Department of Physical Education and Sport Sciences Federal University of Pernambuco Vitória de Santo Antão Brazil
| | - Valdir Braga
- Biotechnology Department Biotechnology Centre Federal University of Paraíba João Pessoa Brazil
| | - José Luiz Brito Alves
- Department of Nutrition Health Sciences Centre Federal University of Paraíba João Pessoa Brazil
- Biotechnology Department Biotechnology Centre Federal University of Paraíba João Pessoa Brazil
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16
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de Araújo EV, Guimarães KSDL, Magnani M, Cruz JC, Vidal H, Braga VDA, de Brito Alves JL. Maternal dyslipidemia during pregnancy and lactation increases blood pressure and disrupts cardiorespiratory and glucose hemostasis in female rat offspring. Appl Physiol Nutr Metab 2019; 44:925-936. [DOI: 10.1139/apnm-2018-0756] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Hypertension and metabolic disorders evidenced in adults who have been exposed to nutritional insults during early life may be sex-dependent. We evaluated if blood pressure (BP), cardiorespiratory control, and metabolic parameters are affected in female offspring (FO) from dams fed a dyslipidaemic diet during pregnancy and lactation. FO was obtained from dams who received control (CTL) or dyslipidaemic diets during pregnancy and lactation. The effects of a maternal dyslipidaemic diet on BP, cardiorespiratory control, and biochemical parameters were assessed at 30 and 90 days of age. The experimental protocol based on a dyslipidaemic diet intervention was effective in developing maternal dyslipidemia. At 30 days of age, the FO from dyslipidaemic dams displayed disordered respiratory pattern, enhanced ventilatory response to hypercapnia (P < 0.05), and increased serum levels of total cholesterol and triglycerides (P < 0.05) when compared with CTL female offspring. At 90 days of age, FO from dyslipidaemic dams had augmented BP (P < 0.05), exacerbated cardiorespiratory responses to hypercapnia (P < 0.05), enhanced pressor responses to peripheral chemoreflex activation (P < 0.05), impaired baroreflex (P < 0.05), and larger delta variations in arterial pressure after ganglionic blockade (P < 0.05). Furthermore, during oral glucose and insulin tolerance tests, FO from dyslipidaemic dams exhibited altered glucose tolerance and insulin sensitivity (P < 0.05) when compared with FO from CTL dams. Altered breathing linked to enhanced central and peripheral chemosensitivity, impaired baroreflex, and augmented sympathetic tone may be predisposing factors for increased BP and metabolic disorders in female offspring from dyslipidaemic dams.
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Affiliation(s)
- Emmanuel Veríssimo de Araújo
- Department of Nutrition, Health Sciences Center, Federal University of Paraiba, Joao Pessoa 58051-900, Brazil
- Biotechnology Center, Federal University of Paraiba, João Pessoa 58051-900, Brazil
| | | | - Marciane Magnani
- Department of Food Engineering, Technology Center, Federal University of Paraiba, Joao Pessoa 58051-900, Brazil
| | - Josiane Campos Cruz
- Biotechnology Center, Federal University of Paraiba, João Pessoa 58051-900, Brazil
| | - Hubert Vidal
- Univ-Lyon, CarMeN (Cardio, Metabolism, Diabetes and Nutrition) Laboratory, INSERM U1060, INRA U1397, Université Claude Bernard Lyon 1, INSA Lyon, Oullins, France
| | | | - José Luiz de Brito Alves
- Department of Nutrition, Health Sciences Center, Federal University of Paraiba, Joao Pessoa 58051-900, Brazil
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17
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Intermittent hypoxemia and oxidative stress in preterm infants. Respir Physiol Neurobiol 2019; 266:121-129. [PMID: 31100375 DOI: 10.1016/j.resp.2019.05.006] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 04/17/2019] [Accepted: 05/10/2019] [Indexed: 01/11/2023]
Abstract
Intermittent hypoxemia events (IH) are common in extremely preterm infants and are associated with many poor outcomes including retinopathy or prematurity, wheezing, bronchopulmonary dysplasia, cognitive or language delays and motor impairment. More recent data in animal and rodent models have suggested that specific patterns of IH may increase the risk for morbidity. The pathway by which these high risk patterns of IH initiate a pathological cascade is unknown but animal models suggest that oxidative stress may play a role. This review describes early postnatal patterns of IH in preterm infants, their relationship with morbidity, oxidative stress biomarkers relevant to the newborn infant and the relationship between IH and reactive oxygen species.
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18
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Ali M, Kowkuntla S, Delloro DJ, Galambos C, Hathi D, Janz S, Shokeen M, Tripathi C, Xu H, Yuk J, Zhan F, Tomasson MH, Bates ML. Chronic intermittent hypoxia enhances disease progression in myeloma-resistant mice. Am J Physiol Regul Integr Comp Physiol 2019; 316:R678-R686. [PMID: 30892915 DOI: 10.1152/ajpregu.00388.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Obesity is the only known modifiable risk factor for multiple myeloma (MM), an incurable cancer of bone marrow plasma cells. The mechanism linking the two is unknown. Obesity is associated with an increased risk of sleep apnea, which results in chronic intermittent hypoxia (CIH), and drives solid tumor aggressiveness. Given the link between CIH and solid tumor progression, we tested the hypothesis that CIH drives the proliferation of MM cells in culture and their engraftment and progression in vivo. Malignant mouse 5TGM1 cells were cultured in CIH, static hypoxia, or normoxia as a control in custom, gas-permeable plates. Typically MM-resistant C57BL/6J mice were exposed to 10 h/day CIH (AHI = 12/h), static hypoxia, or normoxia for 7 days, followed by injection with 5TGM1 cells and an additional 28 days of exposure. CIH and static hypoxia slowed the growth of 5TGM1 cells in culture. CIH-exposed mice developed significantly more MM than controls (67 vs. 12%, P = 0.005), evidenced by hindlimb paralysis, gammopathy, bone lesions, and bone tumor formation. Static hypoxia was not a significant driver of MM progression and did not reduce survival (P = 0.117). Interestingly, 5TGM1 cells preferentially engrafted in the bone marrow and promoted terminal disease in CIH mice, despite a lower tumor burden, compared with the positive controls. These first experiments in the context of hematological cancer demonstrate that CIH promotes MM through mechanisms distinct from solid tumors and that sleep apnea may be a targetable risk factor in patients with or at risk for blood cancer.
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Affiliation(s)
- Mahmoud Ali
- Department of Internal Medicine, Hematology and Oncology Division, University of Iowa , Iowa City, Iowa
| | - Sandeep Kowkuntla
- Department of Health and Human Physiology, University of Iowa , Iowa City, Iowa
| | - Derick J Delloro
- Department of Health and Human Physiology, University of Iowa , Iowa City, Iowa
| | - Csaba Galambos
- Department of Pathology and Laboratory Medicine, University of Colorado School of Medicine and Children's Hospital Colorado , Aurora, Colorado
| | - Deep Hathi
- Department of Radiology, Washington University , St. Louis, Missouri
| | - Siegfried Janz
- Department of Pathology, University of Iowa , Iowa City, Iowa
| | - Monica Shokeen
- Department of Radiology, Washington University , St. Louis, Missouri
| | - Chakrapani Tripathi
- Department of Internal Medicine, Hematology and Oncology Division, University of Iowa , Iowa City, Iowa
| | - Hongwei Xu
- Department of Internal Medicine, Hematology and Oncology Division, University of Iowa , Iowa City, Iowa
| | - Jisung Yuk
- Department of Health and Human Physiology, University of Iowa , Iowa City, Iowa
| | - Fenghuang Zhan
- Department of Internal Medicine, Hematology and Oncology Division, University of Iowa , Iowa City, Iowa
| | - Michael H Tomasson
- Department of Internal Medicine, Hematology and Oncology Division, University of Iowa , Iowa City, Iowa
| | - Melissa L Bates
- Department of Internal Medicine, Hematology and Oncology Division, University of Iowa , Iowa City, Iowa.,Stead Family Department of Pediatrics, University of Iowa , Iowa City, Iowa
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19
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Andrade DC, Haine L, Toledo C, Diaz HS, Quintanilla RA, Marcus NJ, Iturriaga R, Richalet JP, Voituron N, Del Rio R. Ventilatory and Autonomic Regulation in Sleep Apnea Syndrome: A Potential Protective Role for Erythropoietin? Front Physiol 2018; 9:1440. [PMID: 30374309 PMCID: PMC6196773 DOI: 10.3389/fphys.2018.01440] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/21/2018] [Indexed: 12/20/2022] Open
Abstract
Obstructive sleep apnea (OSA) is the most common form of sleep disordered breathing and is associated with wide array of cardiovascular morbidities. It has been proposed that during OSA, the respiratory control center (RCC) is affected by exaggerated afferent signals coming from peripheral/central chemoreceptors which leads to ventilatory instability and may perpetuate apnea generation. Treatments focused on decreasing hyperactivity of peripheral/central chemoreceptors may be useful to improving ventilatory instability in OSA patients. Previous studies indicate that oxidative stress and inflammation are key players in the increased peripheral/central chemoreflex drive associated with OSA. Recent data suggest that erythropoietin (Epo) could also be involved in modulating chemoreflex activity as functional Epo receptors are constitutively expressed in peripheral and central chemoreceptors cells. Additionally, there is some evidence that Epo has anti-oxidant/anti-inflammatory effects. Accordingly, we propose that Epo treatment during OSA may reduce enhanced peripheral/central chemoreflex drive and normalize the activity of the RCC which in turn may help to abrogate ventilatory instability. In this perspective article we discuss the potential beneficial effects of Epo administration on ventilatory regulation in the setting of OSA.
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Affiliation(s)
- David C Andrade
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación en Fisiología del Ejercicio, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Liasmine Haine
- Laboratoire Hypoxie and Poumon - EA2363, Université Paris 13, Paris, France
| | - Camilo Toledo
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Hugo S Diaz
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Investigación Biomédica, Universidad Autónoma de Chile, Santiago, Chile
| | | | - Noah J Marcus
- Department of Physiology and Pharmacology, Des Moines University, Des Moines, IA, United States
| | - Rodrigo Iturriaga
- Laboratorio de Neurobiología, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jean-Paul Richalet
- Laboratoire Hypoxie and Poumon - EA2363, Université Paris 13, Paris, France
| | - Nicolas Voituron
- Laboratoire Hypoxie and Poumon - EA2363, Université Paris 13, Paris, France
| | - Rodrigo Del Rio
- Laboratory of Cardiorespiratory Control, Department of Physiology, Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Envejecimiento y Regeneración (CARE), Pontificia Universidad Católica de Chile, Santiago, Chile.,Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas, Chile
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20
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Elliot-Portal E, Laouafa S, Arias-Reyes C, Janes TA, Joseph V, Soliz J. Brain-derived erythropoietin protects from intermittent hypoxia-induced cardiorespiratory dysfunction and oxidative stress in mice. Sleep 2018; 41:4985474. [PMID: 29697839 PMCID: PMC6047438 DOI: 10.1093/sleep/zsy072] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 02/21/2018] [Indexed: 12/21/2022] Open
Abstract
Study Objectives Based on the fact that erythropoietin (Epo) administration in rodents protects against spatial learning and cognitive deficits induced by chronic intermittent hypoxia (CIH)-mediated oxidative damage, here we tested the hypothesis that Epo in the brain protects against cardiorespiratory disorders and oxidative stress induced by CIH in adult mice. Methods Adult control and transgenic mice overexpressing Epo in the brain only (Tg21) were exposed to CIH (21%-10% O2-10 cycles/hour-8 hours/day-7 days) or room air. After CIH exposure, we used the tail cuff method to measure arterial pressure, and whole-body plethysmography to assess the frequency of apneic episodes at rest, minute ventilation, and ventilatory responses to hypoxia and hypercapnia. Finally, the activity of pro-oxidant (XO-xanthine oxidase, and NADPH) and antioxidant (super oxide dismutase) enzymes was evaluated in the cerebral cortex and brainstem. Results Exposure of control mice to CIH significantly increased the heart rate and arterial pressure, the number of apneic events, and the ventilatory response to hypoxia and hypercapnia. Furthermore, CIH increased the ratio of pro-oxidant to antioxidant enzymes in cortex and brainstem tissues. Both physiological and molecular changes induced by CIH were prevented in transgenic Tg21 mice. Conclusions We conclude that the neuroprotective effect of Epo prevents oxidative damage in the brain and cardiorespiratory disorders induced by CIH. Considering that Epo is used in clinics to treat chronic kidney disease and stroke, our data show convincing evidence suggesting that Epo may be a promising alternative drug to treat sleep-disorder breathing.
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Affiliation(s)
- Elizabeth Elliot-Portal
- Centre de Recherche de l’Institut Universitaire, de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - Sofien Laouafa
- Centre de Recherche de l’Institut Universitaire, de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - Christian Arias-Reyes
- Centre de Recherche de l’Institut Universitaire, de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - Tara Adele Janes
- Centre de Recherche de l’Institut Universitaire, de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - Vincent Joseph
- Centre de Recherche de l’Institut Universitaire, de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - Jorge Soliz
- Centre de Recherche de l’Institut Universitaire, de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
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21
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Morgan BJ, Teodorescu M, Pegelow DF, Jackson ER, Schneider DL, Plante DT, Gapinski JP, Hetzel SJ, Dopp JM. Effects of losartan and allopurinol on cardiorespiratory regulation in obstructive sleep apnoea. Exp Physiol 2018; 103:941-955. [PMID: 29750475 DOI: 10.1113/ep087006] [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] [Received: 03/06/2018] [Accepted: 05/08/2018] [Indexed: 12/30/2022]
Abstract
NEW FINDINGS What is the central question of this study? In sleep apnoea, a putative link between intermittent hypoxia and hypertension is the generation of oxygen radicals by angiotensin II and xanthine oxidase within the chemoreflex arc and vasculature. We tested whether chemoreflex control of sympathetic outflow, hypoxic vasodilatation and blood pressure are altered by angiotensin blockade (losartan) and/or xanthine oxidase inhibition (allopurinol). What is the main finding and its importance? Both drugs lowered blood pressure without altering sympathetic outflow, reducing chemoreflex sensitivity or enhancing hypoxic vasodilatation. Losartan and allopurinol are effective therapies for achieving blood pressure control in sleep apnoea. ABSTRACT Chemoreflex sensitization produced by chronic intermittent hypoxia in rats is attenuated by angiotensin II type 1 receptor (AT1 R) blockade. Both AT1 R blockade and xanthine oxidase inhibition ameliorate chronic intermittent hypoxia-induced endothelial dysfunction. We hypothesized that treatment with losartan and allopurinol would reduce chemoreflex sensitivity and improve hypoxic vasodilatation in patients with obstructive sleep apnoea. Eighty-six hypertensive patients with apnoea-hypopnoea index ≥25 events h-1 and no other cardiovascular, pulmonary, renal or metabolic disease were randomly assigned to receive allopurinol, losartan or placebo for 6 weeks. Treatment with other medications and/or continuous positive airway pressure remained unchanged. Tests of chemoreflex sensitivity and hypoxic vasodilatation were performed during wakefulness before and after treatment. Ventilation (pneumotachography), muscle sympathetic nerve activity (microneurography), heart rate (electrocardiography), arterial oxygen saturation (pulse oximetry), blood pressure (sphygmomanometry), forearm blood flow (venous occlusion plethysmography) and cerebral flow velocity (transcranial Doppler ultrasound) were measured during eupnoeic breathing and graded reductions in inspired O2 tension. Losartan and allopurinol lowered arterial pressure measured during eupnoeic breathing and exposure to acute hypoxia. Neither drug altered the slopes of ventilatory, sympathetic or cardiovascular responses to acute hypoxia. We conclude that losartan and allopurinol are viable pharmacotherapeutic adjuncts for achieving blood pressure control in hypertensive obstructive sleep apnoea patients, even those who are adequately treated with continuous positive airway pressure.
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Affiliation(s)
- Barbara J Morgan
- Department of Orthopedics and Rehabilitation, University of Wisconsin-Madison, Madison, WI, USA
| | - Mihaela Teodorescu
- Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA
| | - David F Pegelow
- Department of Pediatrics, University of Wisconsin-Madison, Madison, WI, USA
| | - Emily R Jackson
- Pharmacy Practice Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
| | - Devin L Schneider
- Pharmacy Practice Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
| | - David T Plante
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Scott J Hetzel
- Department of Biostatistics and Medical Informatics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - John M Dopp
- Pharmacy Practice Division, School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
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22
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Morgan BJ, Schrimpf N, Rothman M, Mitzey A, Brownfieldc MS, Speth RC, Dopp JM. Effect of Chronic Intermittent Hypoxia on Angiotensin II Receptors in the Central Nervous System. Clin Exp Hypertens 2018; 41:1-7. [PMID: 29561178 PMCID: PMC6150845 DOI: 10.1080/10641963.2018.1451536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Revised: 02/21/2018] [Accepted: 03/07/2018] [Indexed: 10/17/2022]
Abstract
Chronic intermittent hypoxia (CIH) increases basal sympathetic nervous system activity, augments chemoreflex-induced sympathoexcitation, and raises blood pressure. All effects are attenuated by systemic or intracerebroventricular administration of angiotensin II type 1 receptor (AT1R) antagonists. This study aimed to quantify the effects of CIH on AT1R- and AT2R-like immunoreactivity in the rostroventrolateral medulla (RVLM) and paraventricular nucleus of the hypothalamus (PVN), central regions that are important components of the extended chemoreflex pathway. Eighteen Sprague-Dawley rats were exposed to intermittent hypoxia (FIO2 = 0.10, 1 min at 4-min intervals) for 10 hr/day for 1, 5, 10, or 21 days. After exposure, rats were deeply anesthetized and transcardially perfused with phosphate buffered saline (PBS) followed by 4% paraformaldehyde in PBS. Brains were removed and sectioned coronally into 50 µm slices. Immunohistochemistry was used to quantify AT1R and AT2R in the RVLM and the PVN. In the RVLM, CIH significantly increased the AT1R-like immunoreactivity, but did not alter AT2R immunoreactivity, thereby augmenting the AT1R:AT2R ratio in this nucleus. In the PVN, CIH had no effect on immunoreactivity of either receptor subtype. The current findings provide mechanistic insight into increased basal sympathetic outflow, enhanced chemoreflex sensitivity, and blood pressure elevation observed in rodents exposed to CIH.
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Affiliation(s)
- Barbara J. Morgan
- John Rankin Laboratory of Pulmonary Medicine, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
- Department of Orthopedics and Rehabilitation, School of Medicine and Public Health, University of Wisconsin, Madison, WI, USA
| | - Nicole Schrimpf
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA
| | - Morgan Rothman
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA
| | - Ann Mitzey
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA
| | - Mark S. Brownfieldc
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA
| | - Robert C. Speth
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Ft. Lauderdale, FL, USA
| | - John M. Dopp
- Pharmacy Practice Division, School of Pharmacy, University of Wisconsin, Madison, WI, USA
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Effect of maternal dyslipidaemia on the cardiorespiratory physiology and biochemical parameters in male rat offspring. Br J Nutr 2017; 118:930-941. [DOI: 10.1017/s0007114517003014] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractThe present study evaluated the effects of maternal dyslipidaemia on blood pressure (BP), cardiorespiratory physiology and biochemical parameters in male offspring. Wistar rat dams were fed either a control (CTL) or a dyslipidaemic (DLP) diet during pregnancy and lactation. After weaning, both CTL and DLP offspring received standard diet. On the 30th and 90th day of life, blood samples were collected for metabolic analyses. Direct measurements of BP, respiratory frequency (RF), tidal volume (VT) and ventilation (VE) under baseline condition, as well as during hypercapnia (7 % CO2) and hypoxia (KCN, 0·04 %), were recorded from awake 90-d-old male offspring. DLP dams exhibited raised serum levels of total cholesterol (TC) (4·0-fold), TAG (2·0-fold), VLDL+LDL (7·7-fold) and reduced HDL-cholesterol (2·4-fold), insulin resistance and hepatic steatosis at the end of lactation. At 30 d of age, the DLP offspring showed an increase in the serum levels of TC (P<0·05) and VLDL+LDL (P<0·05) in comparison with CTL offspring. At 90 d of age, DLP offspring exhibited higher mean arterial pressure (MAP, approximately 34 %). In the spectral analysis, the DLP group showed augmented low-frequency (LF) power and LF:high-frequency (HF) ratio when compared with CTL offspring. In addition, the DLP animals showed a larger delta variation in arterial pressure after administration of the ganglionic blocker (P=0·0003). We also found that cardiorespiratory response to hypercapnia and hypoxia was augmented in DLP offspring. In conclusion, the present data show that maternal dyslipidaemia alters cardiorespiratory physiology and may be a predisposing factor for hypertension at adulthood.
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Laouafa S, Ribon-Demars A, Marcouiller F, Roussel D, Bairam A, Pialoux V, Joseph V. Estradiol Protects Against Cardiorespiratory Dysfunctions and Oxidative Stress in Intermittent Hypoxia. Sleep 2017. [PMID: 28633495 DOI: 10.1093/sleep/zsx104] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Study Objectives We tested the hypothesis that estradiol (E2) protects against cardiorespiratory disorders and oxidative stress induced by chronic intermittent hypoxia (CIH) in adult female rats. Methods Sprague-Dawley female rats (230-250 g) were ovariectomized and implanted with osmotic pumps delivering vehicle or E2 (0.5 mg/kg/d). After 14 days of recovery, the rats were exposed to CIH (21%-10% O2: 8 h/d, 10 cycles per hour) or room air (RA). After 7 days of CIH or RA exposure, we measured arterial pressures (tail cuff), metabolic rate (indirect calorimetry), minute ventilation, the frequency of sighs and apneas at rest, and ventilatory responses to hypoxia and hypercapnia (whole body plethysmography). We collected the cerebral cortex, brainstem, and adrenal glands to measure the activity of NADPH and xanthine oxidase (pro-oxidant enzymes), glutathione peroxidase, and the mitochondrial and cytosolic superoxide dismutase (antioxidant enzymes) and measured lipid peroxidation and advanced oxidation protein products (markers of oxidative stress). Results CIH increased arterial pressure, the frequency of apnea at rest, and the hypoxic and hypercapnic ventilatory responses and reduced metabolic rate. CIH also increased oxidant enzyme activities and decreased antioxidant activity in the cortex. E2 treatment reduced body weight and prevented the effects of CIH. Conclusions E2 prevents cardiorespiratory disorders and oxidative stress induced by CIH. These observations may help to better understand the underlying mechanisms linking menopause and occurrence of sleep apnea in women and highlight a potential advantage of hormone therapy.
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Affiliation(s)
- Sofien Laouafa
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada.,CNRS, UMR 5023, Université Claude Bernard Lyon 1, Villeurbanne, France
| | - Alexandra Ribon-Demars
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada.,Univ Lyon, Université Claude Bernard Lyon 1, Laboratoire interuniversitaire de biologie de la motricité EA7424, Villeurbanne, France
| | - François Marcouiller
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - Damien Roussel
- CNRS, UMR 5023, Universite´ Claude Bernard Lyon 1, Villeurbanne, France
| | - Aida Bairam
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
| | - Vincent Pialoux
- Univ Lyon, Université Claude Bernard Lyon 1, Laboratoire interuniversitaire de biologie de la motricité EA7424, Villeurbanne, France.,Institut Universitaire de France, Paris, France
| | - Vincent Joseph
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec City, Québec, Canada
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Toschi-Dias E, Rondon MUPB, Cogliati C, Paolocci N, Tobaldini E, Montano N. Contribution of Autonomic Reflexes to the Hyperadrenergic State in Heart Failure. Front Neurosci 2017; 11:162. [PMID: 28424575 PMCID: PMC5372354 DOI: 10.3389/fnins.2017.00162] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/13/2017] [Indexed: 12/28/2022] Open
Abstract
Heart failure (HF) is a complex syndrome representing the clinical endpoint of many cardiovascular diseases of different etiology. Given its prevalence, incidence and social impact, a better understanding of HF pathophysiology is paramount to implement more effective anti-HF therapies. Based on left ventricle (LV) performance, HF is currently classified as follows: (1) with reduced ejection fraction (HFrEF); (2) with mid-range EF (HFmrEF); and (3) with preserved EF (HFpEF). A central tenet of HFrEF pathophysiology is adrenergic hyperactivity, featuring increased sympathetic nerve discharge and a progressive loss of rhythmical sympathetic oscillations. The role of reflex mechanisms in sustaining adrenergic abnormalities during HFrEF is increasingly well appreciated and delineated. However, the same cannot be said for patients affected by HFpEF or HFmrEF, whom also present with autonomic dysfunction. Neural mechanisms of cardiovascular regulation act as “controller units,” detecting and adjusting for changes in arterial blood pressure, blood volume, and arterial concentrations of oxygen, carbon dioxide and pH, as well as for humoral factors eventually released after myocardial (or other tissue) ischemia. They do so on a beat-to-beat basis. The central dynamic integration of all these afferent signals ensures homeostasis, at rest and during states of physiological or pathophysiological stress. Thus, the net result of information gathered by each controller unit is transmitted by the autonomic branch using two different codes: intensity and rhythm of sympathetic discharges. The main scope of the present article is to (i) review the key neural mechanisms involved in cardiovascular regulation; (ii) discuss how their dysfunction accounts for the hyperadrenergic state present in certain forms of HF; and (iii) summarize how sympathetic efferent traffic reveal central integration among autonomic mechanisms under physiological and pathological conditions, with a special emphasis on pathophysiological characteristics of HF.
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Affiliation(s)
- Edgar Toschi-Dias
- Heart Institute (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São PauloSão Paulo, Brazil.,Department of Internal Medicine, Fondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoMilan, Italy
| | | | - Chiara Cogliati
- Medicina ad Indirizzo Fisiopatologico, ASST Fatebenefratelli SaccoMilan, Italy
| | - Nazareno Paolocci
- Division of Cardiology, Department of Medicine, Johns Hopkins Medical InstitutionsBaltimore, MD, USA.,Dipartimento di Medicina Sperimentale, Universita' degli Studi di PerugiaPerugia, Italy
| | - Eleonora Tobaldini
- Department of Internal Medicine, Fondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoMilan, Italy.,Dipartimento di Dipartimento Scienze cliniche e di comunità, Università degli Studi di MilanoMilan, Italy
| | - Nicola Montano
- Department of Internal Medicine, Fondazione IRCCS Ca' Granda Ospedale Maggiore PoliclinicoMilan, Italy.,Dipartimento di Dipartimento Scienze cliniche e di comunità, Università degli Studi di MilanoMilan, Italy
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