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Wang Y, Deng T, Zhao X, Shao L, Chen J, Fu C, He W, Wang X, Wang H, Yuan F, Wang S. Control of breathing by orexinergic signaling in the nucleus tractus solitarii. Sci Rep 2024; 14:7473. [PMID: 38553555 PMCID: PMC10980752 DOI: 10.1038/s41598-024-58075-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024] Open
Abstract
Orexin signaling plays a facilitatory role in respiration. Abnormalities in orexin levels correlate with disordered breathing patterns and impaired central respiratory chemoreception. Nucleus tractus solitarii (NTS) neurons expressing the transcription factor Phox2b contribute to the chemoreceptive regulation of respiration. However, the extent to which orexinergic signaling modulates respiratory activity in these Phox2b-expressing NTS neurons remains unclear. In the present study, the injection of orexin A into the NTS significantly increased the firing rate of the phrenic nerve. Further analysis using fluorescence in situ hybridization and immunohistochemistry revealed that orexin 1 receptors (OX1Rs) were primarily located in the ventrolateral subdivision of the NTS and expressed in 25% of Phox2b-expressing neurons. Additionally, electrophysiological recordings showed that exposure to orexin A increased the spontaneous firing rate of Phox2b-expressing neurons. Immunostaining experiments with cFos revealed that the OX1R-residing Phox2b-expressing neurons were activated by an 8% CO2 stimulus. Crucially, OX1R knockdown in these NTS neurons notably blunted the ventilatory response to 8% CO2, alongside an increase in sigh-related apneas. In conclusion, orexinergic signaling in the NTS facilitates breathing through the activation of OX1Rs, which induces the depolarization of Phox2b-expressing neurons. OX1Rs are essential for the involvement of Phox2b-expressing NTS neurons in the hypercapnic ventilatory response.
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Affiliation(s)
- Yakun Wang
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China
- Department of Sleep Medicine, Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Tianjiao Deng
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xue Zhao
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Liuqi Shao
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Jinting Chen
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Congrui Fu
- Nursing School, Hebei Medical University, Shijiazhuang, China
| | - Wei He
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xiaoyi Wang
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China
| | - Hanqiao Wang
- Department of Sleep Medicine, Third Hospital of Hebei Medical University, Shijiazhuang, China
| | - Fang Yuan
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China
| | - Sheng Wang
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei, China.
- Hebei Key Laboratory of Neurophysiology, Shijiazhuang, China.
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Hao Y, Wei Z, Wang S, An P, Huang Y, Yu L, Zhu M, Yu H, Yuan F, Wang S. Inhibition of SOCS3 signaling in the nucleus tractus solitarii and retrotrapezoid nucleus alleviates hypoventilation in diet-induced obese male mice. Brain Res 2024; 1822:148608. [PMID: 37778648 DOI: 10.1016/j.brainres.2023.148608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 09/22/2023] [Accepted: 09/26/2023] [Indexed: 10/03/2023]
Abstract
The central leptin signaling system has been found to facilitate breathing and is linked to obesity-related hypoventilation. Activation of leptin signaling in the nucleus tractus solitarii (NTS) and retrotrapezoid nucleus (RTN) enhances respiratory drive. In this study, we investigated how medullary leptin signaling contributes to hypoventilation and whether respective deletion of SOCS3 in the NTS and RTN could mitigate hypoventilation in diet-induced obesity (DIO) male mice. Our findings revealed a decrease in the number of CO2-activated NTS neurons and downregulation of acid-sensing ion channels in DIO mice compared to lean control mice. Moreover, NTS leptin signaling was disrupted, as evidenced by the downregulation of phosphorylated STAT3 and the upregulation of SOCS3 in DIO mice. Importantly, deleting SOCS3 in the NTS and RTN significantly improved the diminished hypercapnic ventilatory response in DIO mice. In conclusion, our study suggests that disrupted medullary leptin signaling contributes to obesity-related hypoventilation, and inhibiting the upregulated SOCS3 in the NTS and RTN can alleviate this condition.
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Affiliation(s)
- Yinchao Hao
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei Province, China; Functional Laboratory, Experimental Center for Teaching, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Ziqian Wei
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Shuang Wang
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Pei An
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Yifei Huang
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Lingxiao Yu
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Mengchu Zhu
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Hongxiao Yu
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Fang Yuan
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei Province, China; Hebei Key Laboratory of Neurophysiology, Shijiazhuang, Hebei Province, China.
| | - Sheng Wang
- Department of Neurobiology, Hebei Medical University, Shijiazhuang, Hebei Province, China; Hebei Key Laboratory of Neurophysiology, Shijiazhuang, Hebei Province, China.
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Amorim MR, Aung O, Mokhlesi B, Polotsky VY. Leptin-mediated neural targets in obesity hypoventilation syndrome. Sleep 2022; 45:zsac153. [PMID: 35778900 PMCID: PMC9453616 DOI: 10.1093/sleep/zsac153] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 06/20/2022] [Indexed: 07/30/2023] Open
Abstract
Obesity hypoventilation syndrome (OHS) is defined as daytime hypercapnia in obese individuals in the absence of other underlying causes. In the United States, OHS is present in 10%-20% of obese patients with obstructive sleep apnea and is linked to hypoventilation during sleep. OHS leads to high cardiorespiratory morbidity and mortality, and there is no effective pharmacotherapy. The depressed hypercapnic ventilatory response plays a key role in OHS. The pathogenesis of OHS has been linked to resistance to an adipocyte-produced hormone, leptin, a major regulator of metabolism and control of breathing. Mechanisms by which leptin modulates the control of breathing are potential targets for novel therapeutic strategies in OHS. Recent advances shed light on the molecular pathways related to the central chemoreceptor function in health and disease. Leptin signaling in the nucleus of the solitary tract, retrotrapezoid nucleus, hypoglossal nucleus, and dorsomedial hypothalamus, and anatomical projections from these nuclei to the respiratory control centers, may contribute to OHS. In this review, we describe current views on leptin-mediated mechanisms that regulate breathing and CO2 homeostasis with a focus on potential therapeutics for the treatment of OHS.
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Affiliation(s)
- Mateus R Amorim
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - O Aung
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Babak Mokhlesi
- Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, Rush University Medical Center, Chicago, IL, USA
| | - Vsevolod Y Polotsky
- Department of Medicine, Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Glovak ZT, Angel C, O’Brien CB, Baghdoyan HA, Lydic R. Buprenorphine differentially alters breathing among four congenic mouse lines as a function of dose, sex, and leptin status. Respir Physiol Neurobiol 2022; 297:103834. [PMID: 34954128 PMCID: PMC8810735 DOI: 10.1016/j.resp.2021.103834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 12/01/2021] [Accepted: 12/20/2021] [Indexed: 01/29/2023]
Abstract
The opioid buprenorphine alters breathing and the cytokine leptin stimulates breathing. Obesity increases the risk for respiratory disorders and can lead to leptin resistance. This study tested the hypothesis that buprenorphine causes dose-dependent changes in breathing that vary as a function of obesity, leptin status, and sex. Breathing measures were acquired from four congenic mouse lines: female and male wild type C57BL/6J (B6) mice, obese db/db and ob/ob mice with leptin dysfunction, and male B6 mice with diet-induced obesity. Mice were injected intraperitoneally with saline (control) and five doses of buprenorphine (0.1, 0.3, 1.0, 3.0, 10 mg/kg). Buprenorphine caused dose-dependent decreases in respiratory frequency while increasing tidal volume, minute ventilation, and respiratory duty cycle. The effects of buprenorphine varied significantly with leptin status and sex. Buprenorphine decreased minute ventilation variability in all mice. The present findings highlight leptin status as an important modulator of respiration and encourage future studies aiming to elucidate the mechanisms through which leptin status alters breathing.
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Affiliation(s)
| | - Chelsea Angel
- Anesthesiology, University of Michigan Health System, Ann Arbor, MI 48105
| | | | - Helen A. Baghdoyan
- Psychology, University of Tennessee, Knoxville TN 37996,Oak Ridge National Laboratory, Oak Ridge, TN 37831
| | - Ralph Lydic
- Psychology, University of Tennessee, Knoxville, TN, 37996, United States; Oak Ridge National Laboratory, Oak Ridge, TN, 37831, United States.
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Yu H, Shi L, Chen J, Jun S, Hao Y, Wang S, Fu C, Zhang X, Lu H, Wang S, Yuan F. A Neural Circuit Mechanism Controlling Breathing by Leptin in the Nucleus Tractus Solitarii. Neurosci Bull 2021; 38:149-165. [PMID: 34212297 PMCID: PMC8821766 DOI: 10.1007/s12264-021-00742-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 05/07/2021] [Indexed: 02/03/2023] Open
Abstract
Leptin, an adipocyte-derived peptide hormone, has been shown to facilitate breathing. However, the central sites and circuit mechanisms underlying the respiratory effects of leptin remain incompletely understood. The present study aimed to address whether neurons expressing leptin receptor b (LepRb) in the nucleus tractus solitarii (NTS) contribute to respiratory control. Both chemogenetic and optogenetic stimulation of LepRb-expressing NTS (NTSLepRb) neurons notably activated breathing. Moreover, stimulation of NTSLepRb neurons projecting to the lateral parabrachial nucleus (LPBN) not only remarkably increased basal ventilation to a level similar to that of the stimulation of all NTSLepRb neurons, but also activated LPBN neurons projecting to the preBötzinger complex (preBötC). By contrast, ablation of NTSLepRb neurons projecting to the LPBN notably eliminated the enhanced respiratory effect induced by NTSLepRb neuron stimulation. In brainstem slices, bath application of leptin rapidly depolarized the membrane potential, increased the spontaneous firing rate, and accelerated the Ca2+ transients in most NTSLepRb neurons. Therefore, leptin potentiates breathing in the NTS most likely via an NTS-LPBN-preBötC circuit.
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Affiliation(s)
- Hongxiao Yu
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Luo Shi
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Jinting Chen
- grid.256883.20000 0004 1760 8442Core Facilities and Centers, Institute of Medicine and Health, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Shirui Jun
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Yinchao Hao
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Shuang Wang
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Congrui Fu
- grid.256883.20000 0004 1760 8442School of Nursing, Hebei Medical University, Shijiazhuang, 050000 Hebei China
| | - Xiang Zhang
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Haiyan Lu
- grid.256883.20000 0004 1760 8442Department of Orthodontics, College of Stomatology, Hebei Medical University, Shijiazhuang, 050017 Hebei China
| | - Sheng Wang
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China ,Hebei Key Laboratory of Neurophysiology, Shijiazhuang, 050017 Hebei China
| | - Fang Yuan
- grid.256883.20000 0004 1760 8442Department of Physiology, Hebei Medical University, Shijiazhuang, 050017 Hebei China ,Hebei Key Laboratory of Neurophysiology, Shijiazhuang, 050017 Hebei China
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Amorim MR, Dergacheva O, Fleury-Curado T, Pho H, Freire C, Mendelowitz D, Branco LGS, Polotsky VY. The Effect of DREADD Activation of Leptin Receptor Positive Neurons in the Nucleus of the Solitary Tract on Sleep Disordered Breathing. Int J Mol Sci 2021; 22:6742. [PMID: 34201760 PMCID: PMC8269100 DOI: 10.3390/ijms22136742] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 06/19/2021] [Indexed: 12/14/2022] Open
Abstract
Obstructive sleep apnea (OSA) is recurrent obstruction of the upper airway due to the loss of upper airway muscle tone during sleep. OSA is highly prevalent, especially in obesity. There is no pharmacotherapy for OSA. Previous studies have demonstrated the role of leptin, an adipose-tissue-produced hormone, as a potent respiratory stimulant. Leptin signaling via a long functional isoform of leptin receptor, LEPRb, in the nucleus of the solitary tract (NTS), has been implicated in control of breathing. We hypothesized that leptin acts on LEPRb positive neurons in the NTS to increase ventilation and maintain upper airway patency during sleep in obese mice. We expressed designer receptors exclusively activated by designer drugs (DREADD) selectively in the LEPRb positive neurons of the NTS of Leprb-Cre-GFP mice with diet-induced obesity (DIO) and examined the effect of DREADD ligand, J60, on tongue muscle activity and breathing during sleep. J60 was a potent activator of LEPRb positive NTS neurons, but did not stimulate breathing or upper airway muscles during NREM and REM sleep. We conclude that, in DIO mice, the stimulating effects of leptin on breathing during sleep are independent of LEPRb signaling in the NTS.
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Affiliation(s)
- Mateus R. Amorim
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA; (T.F.-C.); (H.P.); (C.F.)
- Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo 14040-904, Brazil;
| | - Olga Dergacheva
- Department of Pharmacology and Physiology, George Washington University, Washington, DC 20037, USA; (O.D.); (D.M.)
| | - Thomaz Fleury-Curado
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA; (T.F.-C.); (H.P.); (C.F.)
| | - Huy Pho
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA; (T.F.-C.); (H.P.); (C.F.)
| | - Carla Freire
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA; (T.F.-C.); (H.P.); (C.F.)
| | - David Mendelowitz
- Department of Pharmacology and Physiology, George Washington University, Washington, DC 20037, USA; (O.D.); (D.M.)
| | - Luiz G. S. Branco
- Dental School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo 14040-904, Brazil;
| | - Vsevolod Y. Polotsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21224, USA; (T.F.-C.); (H.P.); (C.F.)
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