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Herlihy R, Frasson Dos Reis L, Gvritishvili A, Kvizhinadze M, Dybas E, Malhotra A, Fenik VB, Rukhadze I. Chronic intermittent hypoxia attenuates noradrenergic innervation of hypoglossal motor nucleus. Respir Physiol Neurobiol 2024; 321:104206. [PMID: 38142024 PMCID: PMC10872249 DOI: 10.1016/j.resp.2023.104206] [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: 10/10/2023] [Revised: 12/11/2023] [Accepted: 12/19/2023] [Indexed: 12/25/2023]
Abstract
The state-dependent noradrenergic activation of hypoglossal motoneurons plays an important role in the maintenance of upper airway patency and pathophysiology of obstructive sleep apnea (OSA). Chronic intermittent hypoxia (CIH), a major pathogenic factor of OSA, contributes to the risk for developing neurodegenerative disorders in OSA patients. Using anterograde tracer, channelrhodopsin-2, we mapped axonal projections from noradrenergic A7 and SubCoeruleus neurons to hypoglossal nucleus in DBH-cre mice and assessed the effect of CIH on these projections. We found that CIH significantly reduced the number of axonal projections from SubCoeruleus neurons to both dorsal (by 68%) and to ventral (by73%) subregions of the hypoglossal motor nucleus compared to sham-treated animals. The animals' body weight was also negatively affected by CIH. Both effects, the decrease in axonal projections and body weight, were more pronounced in male than female mice, which was likely caused by less sensitivity of female mice to CIH as compared to males. The A7 neurons appeared to have limited projections to the hypoglossal nucleus. Our findings suggest that CIH-induced reduction of noradrenergic innervation of hypoglossal motoneurons may exacerbate progression of OSA, especially in men.
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Affiliation(s)
- Rachael Herlihy
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA
| | - Leonardo Frasson Dos Reis
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA
| | - Anzor Gvritishvili
- VA West Los Angeles Medical Center, VAGLAHS, West Los Angeles, CA 90073, USA
| | - Maya Kvizhinadze
- VA West Los Angeles Medical Center, VAGLAHS, West Los Angeles, CA 90073, USA
| | - Elizabeth Dybas
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA
| | - Atul Malhotra
- University of California San Diego, San Diego, CA 92093, USA
| | - Victor B Fenik
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA; VA West Los Angeles Medical Center, VAGLAHS, West Los Angeles, CA 90073, USA.
| | - Irma Rukhadze
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY 12208, USA; VA West Los Angeles Medical Center, VAGLAHS, West Los Angeles, CA 90073, USA; Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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Ganouna-Cohen G, Marcouiller F, Blachot-Minassian B, Demarest M, Beauparlant CJ, Droit A, Belaidi E, Bairam A, Joseph V. Loss of testosterone induces postprandial insulin resistance and increases the expression of the hepatic antioxidant flavin-containing monooxygenases in mice exposed to intermittent hypoxia. Acta Physiol (Oxf) 2024; 240:e14089. [PMID: 38230898 DOI: 10.1111/apha.14089] [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: 06/25/2023] [Revised: 11/29/2023] [Accepted: 01/01/2024] [Indexed: 01/18/2024]
Abstract
AIM We tested the hypothesis that low testosterone alters the effects of intermittent hypoxia (IH) on glucose homeostasis, hepatic oxidative stress, and transcriptomic profile in male mice. METHODS We used sham-operated or orchiectomized (ORX) mice exposed to normoxia (Nx) or IH for 2 weeks. We performed fasting insulin and glucose tolerance tests and assessed fasting and postprandial insulin resistance with the HOMA-IR. The activity of hepatic prooxidant (NADPH oxidase-NOX), antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase-SOD, Cat, GPx), lipid peroxidation (MDA concentration), and the total concentration of glutathione (GSH) were measured under postprandial conditions. mRNA sequencing and pathway enrichment analyses were used to identify hepatic genes underlying the interactions between IH and testosterone. RESULTS In Sham mice, IH improves fasting insulin sensitivity and glucose tolerance, while there are no effects of IH in ORX mice. In ORX mice, IH induces postprandial hyperinsulinemia, insulin resistance, and a prooxidant profile of enzyme activity (low SOD activity) without altering hepatic MDA and GSH content. ORX and IH altered the expression of genes involved in oxidoreductase activities, cytochromes-dependent pathways, and glutathione metabolism. Among the genes upregulated in ORX-IH mice, the flavin-containing monooxygenases (FMO) are particularly relevant since these are potent hepatic antioxidants that could help prevent overt oxidative stress in ORX-IH mice. CONCLUSION Low levels of testosterone in male mice exposed to IH induce post-prandial hyperinsulinemia and insulin resistance and determine the mechanisms by which the liver handles IH-induced oxidative stress.
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Affiliation(s)
- Gauthier Ganouna-Cohen
- Département de Pédiatrie, Faculté de Médecine, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Quebec, Canada
| | - François Marcouiller
- Département de Pédiatrie, Faculté de Médecine, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Quebec, Canada
| | - Britanny Blachot-Minassian
- Département de Pédiatrie, Faculté de Médecine, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Quebec, Canada
- HP2, INSERM, U1300, Université Grenoble Alpes, Grenoble, France
| | - Maud Demarest
- Département de Pédiatrie, Faculté de Médecine, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Quebec, Canada
| | - Charles Joly Beauparlant
- Département de Médecine Moléculaire, Faculté de Médecine, Centre de Recherche du Centre Hospitalo-Universitaire de Québec, Québec, Quebec, Canada
| | - Arnaud Droit
- Département de Médecine Moléculaire, Faculté de Médecine, Centre de Recherche du Centre Hospitalo-Universitaire de Québec, Québec, Quebec, Canada
| | - Elise Belaidi
- HP2, INSERM, U1300, Université Grenoble Alpes, Grenoble, France
- UMR5305-LBTI, CNRS, Institut de Biologie et Chimie des Protéines, Lyon, France
| | - Aida Bairam
- Département de Pédiatrie, Faculté de Médecine, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Quebec, Canada
| | - Vincent Joseph
- Département de Pédiatrie, Faculté de Médecine, Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Quebec, Canada
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Goulet N, Marcoux C, Bourgon V, Morin R, Mauger JF, Amaratunga R, Imbeault P. Biological sex-related differences in the postprandial triglyceride response to intermittent hypoxaemia in young adults: a randomized crossover trial. J Physiol 2024. [PMID: 38285004 DOI: 10.1113/jp285430] [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: 08/01/2023] [Accepted: 01/10/2024] [Indexed: 01/30/2024] Open
Abstract
Obstructive sleep apnoea is characterized by chronic intermittent hypoxaemia and is independently associated with an increased risk of metabolic comorbidities (e.g. type II diabetes and ischaemic heart disease). These comorbidities could be attributable to hypoxaemia-induced alterations in blood lipid profiles. However, it remains unclear whether intermittent hypoxaemia alters triglyceridaemia differently between biological sexes. Therefore, we used a randomized crossover design to examine whether 6 h of moderate intermittent hypoxaemia (15 hypoxaemic cycles/h, 85% oxyhaemoglobin saturation) alters plasma triglyceride levels differently between men and women after a high-fat meal. Relative to men, women displayed lower levels of total triglycerides, in addition to denser triglyceride-rich lipoprotein triglycerides (TRL-TG; mainly very low-density lipoprotein triglycerides and chylomicron remnant triglycerides) and buoyant TRL-TG (mainly chylomicron triglycerides) during normoxia (ambient air) and intermittent hypoxaemia (sex × time: all P ≤ 0.008). Intermittent hypoxaemia led to higher triglyceride levels (condition: all P ≤ 0.016); however, this effect was observed only in men (sex × condition: all P ≤ 0.002). Compared with normoxia, glucose levels were higher in men and lower in women during intermittent hypoxaemia (sex × condition: P < 0.001). The different postprandial responses between biological sexes occurred despite similar reductions in mean oxyhaemoglobin saturation and similar elevations in insulin levels, non-esterified fatty acid levels and mean heart rate (sex × condition: all P ≥ 0.185). These results support growing evidence showing that intermittent hypoxaemia impacts men and women differently, and they might help to explain biological sex-related discrepancies in the rate of certain comorbidities associated with intermittent hypoxaemia. KEY POINTS: Intermittent hypoxaemia is a key characteristic of obstructive sleep apnoea and alters lipid metabolism in multiple tissues, resulting in increased circulating triglyceride levels, an important risk factor for cardiometabolic diseases. Circulating triglyceride levels are regulated differently between biological sexes, with women typically displaying much lower fasting and postprandial triglyceride levels than men, partly explaining why women of all ages experience lower mortality rates from cardiometabolic diseases. In this study, healthy young men and women consumed a high-fat meal and were then exposed to 6 h of intermittent hypoxaemia or ambient air. We show that postprandial triglyceride levels are significantly lower in women compared with men and that intermittent hypoxaemia leads to higher postprandial triglyceride levels in men only. These results might help us to understand better why women living with obstructive sleep apnoea experience lower rates of cardiometabolic diseases (e.g. type II diabetes and ischaemic heart disease) than men living with obstructive sleep apnoea.
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Affiliation(s)
- Nicholas Goulet
- Behavioural and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Caroline Marcoux
- Behavioural and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Vincent Bourgon
- Laboratoire du Sommeil, Département de psychoéducation et de psychologie, Université du Québec en Outaouais, Gatineau, QC, Canada
| | - Renée Morin
- Behavioural and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Jean-François Mauger
- Behavioural and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
| | - Ruwan Amaratunga
- Institut du Savoir Montfort, Montfort Hospital, Ottawa, ON, Canada
| | - Pascal Imbeault
- Behavioural and Metabolic Research Unit, School of Human Kinetics, Faculty of Health Sciences, University of Ottawa, Ottawa, ON, Canada
- Institut du Savoir Montfort, Montfort Hospital, Ottawa, ON, Canada
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Lazarov NE, Atanasova DY. Carotid Body Dysfunction and Mechanisms of Disease. ADVANCES IN ANATOMY, EMBRYOLOGY, AND CELL BIOLOGY 2023; 237:123-138. [PMID: 37946080 DOI: 10.1007/978-3-031-44757-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Emerging evidence shows that the carotid body (CB) dysfunction is implicated in various physiological and pathophysiological conditions. It has been revealed that the CB structure and neurochemical profile alter in certain human sympathetic-related and cardiometabolic diseases. Specifically, a tiny CB with a decrease of glomus cells and their dense-cored vesicles has been seen in subjects with sleep disordered breathing such as sudden infant death syndrome and obstructive sleep apnea patients and people with congenital central hypoventilation syndrome. Moreover, the CB degranulation is accompanied by significantly elevated levels of catecholamines and proinflammatory cytokines in such patients. The intermittent hypoxia stimulates the CB, eliciting augmented chemoreflex drive and enhanced cardiorespiratory and sympathetic responses. High CB excitability due to blood flow restrictions, oxidative stress, alterations in neurotransmitter gases and disruptions of local mediators is also observed in congestive heart failure conditions. On the other hand, the morpho-chemical changes in hypertension include an increase in the CB volume due to vasodilation, altered transmitter phenotype of chemoreceptor cells and elevated production of neurotrophic factors. Accordingly, in both humans and animal models CB denervation prevents the breathing instability and lowers blood pressure. Knowledge of the morphofunctional aspects of the CB, a better understanding of its role in disease and recent advances in human CB translational research would contribute to the development of new therapeutic strategies.
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Affiliation(s)
- Nikolai E Lazarov
- Department of Anatomy and Histology, Faculty of Medicine, Medical University of Sofia, Sofia, Bulgaria.
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