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Fukushi I, Takeda K, Pokorski M, Kono Y, Yoshizawa M, Hasebe Y, Nakao A, Mori Y, Onimaru H, Okada Y. Activation of Astrocytes in the Persistence of Post-hypoxic Respiratory Augmentation. Front Physiol 2021; 12:757731. [PMID: 34690820 PMCID: PMC8531090 DOI: 10.3389/fphys.2021.757731] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/15/2021] [Indexed: 11/16/2022] Open
Abstract
Acute hypoxia increases ventilation. After cessation of hypoxia loading, ventilation decreases but remains above the pre-exposure baseline level for a time. However, the mechanism of this post-hypoxic persistent respiratory augmentation (PHRA), which is a short-term potentiation of breathing, has not been elucidated. We aimed to test the hypothesis that astrocytes are involved in PHRA. To this end, we investigated hypoxic ventilatory responses by whole-body plethysmography in unanesthetized adult mice. The animals breathed room air, hypoxic gas mixture (7% O2, 93% N2) for 2min, and again room air for 10min before and after i.p. administration of low (100mg/kg) and high (300mg/kg) doses of arundic acid (AA), an astrocyte inhibitor. AA suppressed PHRA, with the high dose decreasing ventilation below the pre-hypoxic level. Further, we investigated the role of the astrocytic TRPA1 channel, a putative ventilatory hypoxia sensor, in PHRA using astrocyte-specific Trpa1 knockout (asTrpa1−/−) and floxed Trpa1 (Trpa1f/f) mice. In both Trpa1f/f and asTrpa1−/− mice, PHRA was noticeable, indicating that the astrocyte TRPA1 channel was not directly involved in PHRA. Taken together, these results indicate that astrocytes mediate the PHRA by mechanisms other than TRPA1 channels that are engaged in hypoxia sensing.
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Affiliation(s)
- Isato Fukushi
- Faculty of Health Sciences, Uekusa Gakuen University, Chiba, Japan.,Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
| | - Kotaro Takeda
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Faculty of Rehabilitation, School of Healthcare, Fujita Health University, Toyoake, Japan
| | - Mieczyslaw Pokorski
- Institute of Health Sciences, University of Opole, Opole, Poland.,Faculty of Health Sciences, The Jan Dlugosz University in Czestochowa, Czestochowa, Poland
| | - Yosuke Kono
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Masashi Yoshizawa
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Yohei Hasebe
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Akito Nakao
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Yasuo Mori
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Hiroshi Onimaru
- Department of Physiology, Showa University School of Medicine, Tokyo, Japan
| | - Yasumasa Okada
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
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2
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Marsh BJ, Fryer AD, Jacoby DB, Drake MG. Transient receptor potential ankyrin-1 causes rapid bronchodilation via nonepithelial PGE 2. Am J Physiol Lung Cell Mol Physiol 2020; 318:L943-L952. [PMID: 32233794 DOI: 10.1152/ajplung.00277.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Transient receptor potential ankyrin-1 (TRPA1) is a ligand-gated cation channel that responds to endogenous and exogenous irritants. TRPA1 is expressed on multiple cell types throughout the lungs, but previous studies have primarily focused on TRPA1 stimulation of airway sensory nerves. We sought to understand the integrated physiological airway response to TRPA1 stimulation. The TRPA1 agonists allyl isothiocyanate (AITC) and cinnamaldehyde (CINN) were tested in sedated, mechanically ventilated guinea pigs in vivo. Reproducible bronchoconstrictions were induced by electrical stimulation of the vagus nerves. Animals were then treated with intravenous AITC or CINN. AITC and CINN were also tested on isolated guinea pig and mouse tracheas and postmortem human trachealis muscle strips in an organ bath. Tissues were contracted with methacholine, histamine, or potassium chloride and then treated with AITC or CINN. Some airways were pretreated with TRPA1 antagonists, the cyclooxygenase inhibitor indomethacin, the EP2 receptor antagonist PF 04418948, or tetrodotoxin. AITC and CINN blocked vagally mediated bronchoconstriction in guinea pigs. Pretreatment with indomethacin completely abolished the airway response to TRPA1 agonists. Similarly, AITC and CINN dose-dependently relaxed precontracted guinea pig, mouse, and human airways in the organ bath. AITC- and CINN-induced airway relaxation required TRPA1, prostaglandins, and PGE2 receptor activation. TRPA1-induced airway relaxation did not require epithelium or tetrodotoxin-sensitive nerves. Finally, AITC blocked airway hyperreactivity in two animal models of allergic asthma. These data demonstrate that stimulation of TRPA1 causes bronchodilation of intact airways and suggest that the TRPA1 pathway is a potential pharmacological target for bronchodilation.
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Affiliation(s)
- Brenda J Marsh
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon
| | - Allison D Fryer
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon
| | - David B Jacoby
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon
| | - Matthew G Drake
- Division of Pulmonary and Critical Care Medicine, Oregon Health & Science University, Portland, Oregon
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3
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Alpha lipoic acid attenuates hypoxia-induced apoptosis, inflammation and mitochondrial oxidative stress via inhibition of TRPA1 channel in human glioblastoma cell line. Biomed Pharmacother 2018; 111:292-304. [PMID: 30590317 DOI: 10.1016/j.biopha.2018.12.077] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 12/04/2018] [Accepted: 12/17/2018] [Indexed: 12/20/2022] Open
Abstract
Apoptosis, overload Ca2+ entry and oxidative stress are induced in neurons by hypoxia. Drug-resistant cancer cells are killed by hypoxic conditions. α-Lipoic acid (ALA) has antioxidant and pro-oxidant functions. The TRPA1 channel is activated by oxidative stress and pro-oxidant ALA may have a regulator role in the TRPA1 activity in the human glioblastoma (DBTRG) cells. The aim of this study was to evaluate if a combination therapy of ALA with a hypoxia can alter the effect of this hypoxia through TRPA1 activation in the DBTRG cells. The DBTRG cells were divided into four treatment groups as control, ALA (50 μM), and hypoxia and hypoxia + ALA. Hypoxia in the cells was induced by CoCl2 (200 μM). Apoptosis, Annexin V, mitochondrial membrane depolarization (JC-1), reactive oxygen species (ROS) production, IL-1β, IL-18, caspase 3 and 9 values were increased through activation of TRPA1 (cinnamaldehyde) in the cells by the hypoxia induction, although cell viability, reduced glutathione and glutathione peroxidase values were decreased by the treatments. The values were modulated in the cells by TRPA1 blocker (AP18) and ALA treatments. Involvements of TRPA1 activity on values in the cells were also confirmed by patch-clamp and laser confocal microscopy analyses. In conclusion, apoptotic, inflammatory and oxidant effects of hypoxia were increased by activation of TRPA1, but its action on the values was decreased by the ALA treatment. ALA treatment could be used as an effective strategy in the treatment of hypoxia-induced oxidative stress, apoptosis and inflammation in the neurons.
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4
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Roy A, Farnham MMJ, Derakhshan F, Pilowsky PM, Wilson RJA. Acute intermittent hypoxia with concurrent hypercapnia evokes P2X and TRPV1 receptor-dependent sensory long-term facilitation in naïve carotid bodies. J Physiol 2018; 596:3149-3169. [PMID: 29159869 PMCID: PMC6068228 DOI: 10.1113/jp275001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 11/16/2017] [Indexed: 12/14/2022] Open
Abstract
KEY POINTS Activity-dependent plasticity can be induced in carotid body (CB) chemosensory afferents without chronic intermittent hypoxia (CIH) preconditioning by acute intermittent hypoxia coincident with bouts of hypercapnia (AIH-Hc). Several properties of this acute plasticity are shared with CIH-dependent sensory long-term facilitation (LTF) in that induction is dependent on 5-HT, angiotensin II, protein kinase C and reactive oxygen species. Several properties differ from CIH-dependent sensory LTF; H2 O2 appears to play no part in induction, whereas maintenance requires purinergic P2X2/3 receptor activation and is dependent on transient receptor potential vanilloid type 1 (TRPV1) receptor sensitization. Because P2X2/3 and TRPV1 receptors are located in carotid sinus nerve (CSN) terminals but not presynaptic glomus cells, a primary site of the acute AIH-Hc induced sensory LTF appears to be postsynaptic. Our results obtained in vivo suggest a role for TRPV1-dependent CB activity in acute sympathetic LTF. We propose that P2X-TRPV1-receptor-dependent sensory LTF may constitute an important early mechanism linking sleep apnoea with hypertension and/or cardiovascular disease. ABSTRACT Apnoeas constitute an acute existential threat to neonates and adults. In large part, this threat is detected by the carotid bodies, which are the primary peripheral chemoreceptors, and is combatted by arousal and acute cardiorespiratory responses, including increased sympathetic output. Similar responses occur with repeated apnoeas but they continue beyond the last apnoea and can persist for hours [i.e. ventilatory and sympathetic long-term facilitation (LTF)]. These long-term effects may be adaptive during acute episodic apnoea, although they may prolong hypertension causing chronic cardiovascular impairment. We report a novel mechanism of acute carotid body (CB) plasticity (sensory LTF) induced by repeated apnoea-like stimuli [i.e. acute intermittent hypoxia coincident with bouts of hypercapnia (AIH-Hc)]. This plasticity did not require chronic intermittent hypoxia preconditioning, was dependent on P2X receptors and protein kinase C, and involved heat-sensitive transient receptor potential vanilloid type 1 (TRPV1) receptors. Reactive oxygen species (O2 ·¯) were involved in initiating plasticity only; no evidence was found for H2 O2 involvement. Angiotensin II and 5-HT receptor antagonists, losartan and ketanserin, severely reduced CB responses to individual hypoxic-hypercapnic challenges and prevented the induction of sensory LTF but, if applied after AIH-Hc, failed to reduce plasticity-associated activity. Conversely, TRPV1 receptor antagonism had no effect on responses to individual hypoxic-hypercapnic challenges but reduced plasticity-associated activity by ∼50%. Further, TRPV1 receptor antagonism in vivo reduced sympathetic LTF caused by AIH-Hc, although only if the CBs were functional. These data demonstrate a new mechanism of CB plasticity and suggest P2X-TRPV1-dependent sensory LTF as a novel target for pharmacological intervention in some forms of neurogenic hypertension associated with recurrent apnoeas.
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Affiliation(s)
- Arijit Roy
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, Faculty of MedicineUniversity of CalgaryCalgaryAlbertaCanada
| | | | - Fatemeh Derakhshan
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, Faculty of MedicineUniversity of CalgaryCalgaryAlbertaCanada
| | | | - Richard J. A. Wilson
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, Faculty of MedicineUniversity of CalgaryCalgaryAlbertaCanada
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5
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Huang YC, Yuan ZF, Yang CH, Shen YJ, Lin JY, Lai CJ. Estrogen Modulates the Sensitivity of Lung Vagal C Fibers in Female Rats Exposed to Intermittent Hypoxia. Front Physiol 2018; 9:847. [PMID: 30026705 PMCID: PMC6041459 DOI: 10.3389/fphys.2018.00847] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 06/14/2018] [Indexed: 01/03/2023] Open
Abstract
Obstructive sleep apnea is mainly characterized by intermittent hypoxia (IH), which is associated with hyperreactive airway diseases and lung inflammation. Sensitization of lung vagal C fibers (LVCFs) induced by inflammatory mediators may play a central role in the pathogenesis of airway hypersensitivity. In females, estrogen interferes with inflammatory signaling pathways that may modulate airway hyperreactivity. In this study, we investigated the effects of IH on the reflex and afferent responses of LVCFs to chemical stimulants and lung inflammation in adult female rats, as well as the role of estrogen in these responses. Intact and ovariectomized (OVX) female rats were exposed to room air (RA) or IH for 14 consecutive days. On day 15, IH enhanced apneic responses to right atrial injection of chemical stimulants of LVCFs (e.g., capsaicin, phenylbiguanide, and α,β-methylene-ATP) in intact anesthetized females. Rats subjected to OVX prior to IH exposure exhibited an augmented apneic response to the same dose of stimulants compared with rats subjected to other treatments. Apneic responses to the stimulants were completely abrogated by bilateral vagotomy or perivagal capsaicin treatment, which blocked the neural conduction of LVCFs. Electrophysiological experiments revealed that in IH-exposed rats, OVX potentiated the excitability of LVCFs to stimulants. Moreover, LVCF hypersensitivity in rats subjected to OVX prior to IH exposure was accompanied by enhanced lung inflammation, which was reflected by elevated inflammatory cell infiltration in bronchoalveolar lavage fluid, lung lipid peroxidation, and protein expression of inflammatory cytokines. Supplementation with 17β-estradiol (E2) at a low concentration (30 μg/ml) but not at high concentrations (50 and 150 μg/ml) prevented the augmenting effects of OVX on LVCF sensitivity and lung inflammation caused by IH. These results suggest that ovarian hormones prevent the enhancement of LVCF sensitivity and lung inflammation by IH in female rats, which are related to the effect of low-dose estrogen.
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Affiliation(s)
- Ya-Chen Huang
- Department of Chest Section, Buddhist Tzu Chi General Hospital, Hualien City, Taiwan.,Master Program in Physiological and Anatomical Medicine, School of Medicine, Tzu Chi University, Hualien City, Taiwan
| | - Zung Fan Yuan
- Master Program in Physiological and Anatomical Medicine, School of Medicine, Tzu Chi University, Hualien City, Taiwan.,Department of Physiology, Tzu Chi University, Hualien City, Taiwan
| | - Chang-Huan Yang
- Institute of Physiology, National Yang-Ming University, Taipei, Taiwan
| | - Yan-Jhih Shen
- Ph.D. Program in Pharmacology and Toxicology, School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Jyun-Yi Lin
- Department of Chest Section, Buddhist Tzu Chi General Hospital, Hualien City, Taiwan.,Master Program in Physiological and Anatomical Medicine, School of Medicine, Tzu Chi University, Hualien City, Taiwan
| | - Ching Jung Lai
- Master Program in Physiological and Anatomical Medicine, School of Medicine, Tzu Chi University, Hualien City, Taiwan.,Department of Physiology, Tzu Chi University, Hualien City, Taiwan
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6
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Wu SW, Fowler DK, Shaffer FJ, Lindberg JEM, Peters JH. Ethyl Vanillin Activates TRPA1. J Pharmacol Exp Ther 2017; 362:368-377. [PMID: 28620120 DOI: 10.1124/jpet.116.239384] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 05/19/2017] [Indexed: 01/11/2023] Open
Abstract
The nonselective cation channel transient receptor potential ankryn subtype family 1 (TRPA1) is expressed in neurons of dorsal root ganglia and trigeminal ganglia and also in vagal afferent neurons that innervate the lungs and gastrointestinal tract. Many TRPA1 agonists are reactive electrophilic compounds that form covalent adducts with TRPA1. Allyl isothiocyanate (AITC), the common agonist used to identify TRPA1, contains an electrophilic group that covalently binds with cysteine residues of TRPA1 and confers a structural change on the channel. There is scientific motivation to identify additional compounds that can activate TRPA1 with different mechanisms of channel gating. We provide evidence that ethyl vanillin (EVA) is a TRPA1 agonist. Using fluorescent calcium imaging and whole-cell patch-clamp electrophysiology on dissociated rat vagal afferent neurons and TRPA1-transfected COS-7 cells, we discovered that EVA activates cells also activated by AITC. Both agonists display similar current profiles and conductances. Pretreatment with A967079, a selective TRPA1 antagonist, blocks the EVA response as well as the AITC response. Furthermore, EVA does not activate vagal afferent neurons from TRPA1 knockout mice, showing selectivity for TRPA1 in this tissue. Interestingly, EVA appears to be pharmacologically different from AITC as a TRPA1 agonist. When AITC is applied before EVA, the EVA response is occluded. However, they both require intracellular oxidation to activate TRPA1. These findings suggest that EVA activates TRPA1 but via a distinct mechanism that may provide greater ease for study in native systems compared with AITC and may shed light on differential modes of TRPA1 gating by ligand types.
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Affiliation(s)
- Shaw-Wen Wu
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington (D.K.F., F.J.S., J.E.M.L., J.H.P.); and Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida (S.-w.W.)
| | - Daniel K Fowler
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington (D.K.F., F.J.S., J.E.M.L., J.H.P.); and Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida (S.-w.W.)
| | - Forrest J Shaffer
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington (D.K.F., F.J.S., J.E.M.L., J.H.P.); and Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida (S.-w.W.)
| | - Jonathon E M Lindberg
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington (D.K.F., F.J.S., J.E.M.L., J.H.P.); and Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida (S.-w.W.)
| | - James H Peters
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, Washington (D.K.F., F.J.S., J.E.M.L., J.H.P.); and Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida (S.-w.W.)
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7
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Activation of cannabinoid CB1 receptors suppresses the ROS-induced hypersensitivity of rat vagal lung C-fiber afferents. Pulm Pharmacol Ther 2016; 40:22-9. [DOI: 10.1016/j.pupt.2016.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/21/2016] [Accepted: 06/17/2016] [Indexed: 02/07/2023]
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8
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Yang CH, Shen YJ, Lai CJ, Kou YR. Inflammatory Role of ROS-Sensitive AMP-Activated Protein Kinase in the Hypersensitivity of Lung Vagal C Fibers Induced by Intermittent Hypoxia in Rats. Front Physiol 2016; 7:263. [PMID: 27445853 PMCID: PMC4922301 DOI: 10.3389/fphys.2016.00263] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 06/14/2016] [Indexed: 12/18/2022] Open
Abstract
Obstructive sleep apnea (OSA), manifested by airway exposure to intermittent hypoxia (IH), is associated with excess reactive oxygen species (ROS) production in airways, airway inflammation, and hyperreactive airway diseases. The cause-effect relationship for these events remains unclear. We investigated the inflammatory role of ROS-sensitive AMP-activated protein kinase (AMPK) in IH-induced airway hypersensitivity mediated by lung vagal C fibers (LVCFs) in rats. Conscious rats were exposed to room air (RA) or IH with or without treatment with N-acetyl-L-cysteine (NAC, an antioxidant), Compound C (an AMPK inhibitor), ibuprofen (a cyclooxygenase inhibitor), or their vehicles. Immediately after exposure (24 h), we found that intravenous capsaicin, phenylbiguanide, or α,β-methylene-ATP evoked augmented LVCF-mediated apneic responses and LVCF afferent responses in rats subjected to IH exposure in comparison with those in RA rats. The potentiating effect of IH on LVCF responses decreased at 6 h after and vanished at 12 h after the termination of IH exposure. The potentiating effect of IH on LVCF-mediated apneic and LVCF afferent responses was significantly attenuated by treatment with NAC, compound C, or ibuprofen, but not by their vehicles. Further biochemical analysis revealed that rats exposed to IH displayed increased lung levels of lipid peroxidation (an index of oxidative stress), AMPK phosphorylation (an index of AMPK activation), and prostaglandin E2 (a cyclooxygenase metabolite), compared with those exposed to RA. IH-induced increase in lipid peroxidation was considerably suppressed by treatment with NAC but not by compound C or ibuprofen. IH-induced increase in AMPK phosphorylation was totally abolished by NAC or compound C but not by ibuprofen. IH-induced increase in prostaglandin E2 was considerably prevented by any of these three inhibitor treatments. The vehicles of these inhibitors exerted no significant effect on the three IH-induced responses. These results suggest that 24-h IH exposure sensitizes LVCFs, leading to an exaggerated reflex and afferent responses to chemical stimulants in rats. Moreover, this IH-induced LVCF sensitization is mediated through a cascade of inflammatory responses in the airways involving increases in ROS, AMPK activation, and cyclooxygenase metabolite release.
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Affiliation(s)
- Chang-Huan Yang
- Institute of Physiology, School of Medicine, National Yang-Ming University Taipei, Taiwan
| | - Yan-Jhih Shen
- Department of Pharmacology and Toxicology, School of Medicine, Tzu Chi University Hualien, Taiwan
| | - Ching Jung Lai
- Department of Physiology, Tzu Chi University Hualien, Taiwan
| | - Yu Ru Kou
- Institute of Physiology, School of Medicine, National Yang-Ming University Taipei, Taiwan
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9
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Yang CH, Zhuang WL, Shen YJ, Lai CJ, Kou YR. NADPH Oxidase-Derived ROS Induced by Chronic Intermittent Hypoxia Mediates Hypersensitivity of Lung Vagal C Fibers in Rats. Front Physiol 2016; 7:166. [PMID: 27242540 PMCID: PMC4860401 DOI: 10.3389/fphys.2016.00166] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 04/21/2016] [Indexed: 12/04/2022] Open
Abstract
Obstructive sleep apnea (OSA), manifested by exposure to chronic intermittent hypoxia (CIH) and excess production of reactive oxygen species (ROS) in the airways, is associated with hyperreactive airway diseases. ROS, particularly when created by NADPH oxidase, are known to sensitize lung vagal C fibers (LVCFs), which may contribute to airway hypersensitivity pathogenesis. We investigated whether CIH augments the reflex and afferent responses of LVCFs to chemical stimulants and the roles of ROS and NADPH oxidase in such airway hypersensitivity. Rats were exposed to room air (RA) or CIH with/without daily treatment with MnTMPyP (a superoxide anion scavenger), apocynin (an NADPH oxidase inhibitor), or vehicle. At 16 h after their last exposure, intravenous capsaicin, adenosine, or α,β-methylene-ATP evoked an augmented apneic response in anesthetized rats with 14-days CIH exposure, compared to anesthetized rats with 14-days RA exposure. The augmented apneic responses to these LVCF stimulants were abolished by bilateral vagotomy or perivagal capsaicin treatment, which block LVCFs neural conduction and were significantly suppressed by treatment with MnTMPyP or apocynin, but not vehicle. Electrophysiological studies revealed that 14-days CIH exposure potentiated the responses of LVCFs to these stimulants. This effect was inhibited by treatment with MnTMPyP or apocynin treatment and was not seen in rats who received 7-days of CIH exposure. Biochemical analysis indicated that 14-days CIH exposure increased both lung lipid peroxidation, which is indicative of oxidative stress, and expression of the p47phox subunit in the membrane fraction of lung tissue, which is an index of NADPH oxidase activation. The former was prevented by treatment with either MnTMPyP or apocynin, while the later was prevented by treatment with apocynin only. These results suggest that 14-days CIH exposure sensitizes LVCFs in rats, leading to an exaggerated reflex and afferent responses to stimulants and that this sensitization is mediated via ROS generated by NADPH oxidase.
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Affiliation(s)
- Chang-Huan Yang
- School of Medicine, Institute of Physiology, National Yang-Ming University Taipei, Taiwan
| | - Wei-Ling Zhuang
- Department of Physiology, Tzu Chi University Hualien, Taiwan
| | - Yan-Jhih Shen
- PhD Program in Pharmacology and Toxicology, School of Medicine, Tzu Chi University Hualien, Taiwan
| | - Ching Jung Lai
- Department of Physiology, Tzu Chi University Hualien, Taiwan
| | - Yu Ru Kou
- School of Medicine, Institute of Physiology, National Yang-Ming University Taipei, Taiwan
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10
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De Logu F, Patacchini R, Fontana G, Geppetti P. TRP functions in the broncho-pulmonary system. Semin Immunopathol 2016; 38:321-9. [PMID: 27083925 DOI: 10.1007/s00281-016-0557-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2015] [Accepted: 02/09/2016] [Indexed: 12/23/2022]
Abstract
The current understanding of the role of transient receptor potential (TRP) channels in the airways and lung was initially based on the localization of a series of such channels in a subset of sensory nerve fibers of the respiratory tract. Soon after, TRP channel expression and function have been identified in respiratory nonneuronal cells. In these two locations, TRPs regulate physiological processes aimed at integrating different stimuli to maintain homeostasis and to react to harmful agents and tissue injury by building up inflammatory responses and repair processes. There is no doubt that TRPs localized in the sensory network contribute to airway neurogenic inflammation, and emerging evidence underlines the role of nonneuronal TRPs in orchestrating inflammation and repair in the respiratory tract. However, recent basic and clinical studies have offered clues regarding the contribution of neuronal and nonneuronal TRPs in the mechanism of asthma, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, cough, and other respiratory diseases.
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Affiliation(s)
- Francesco De Logu
- Clinical Pharmacology Unit, Department of Health Sciences, University of Florence, Viale Pieraccini, 6, 50139, Florence, Italy
| | - Riccardo Patacchini
- Clinical Pharmacology Unit, Department of Health Sciences, University of Florence, Viale Pieraccini, 6, 50139, Florence, Italy
- Chiesi Farmaceutici S.p.A, Parma, Italy
| | - Giovanni Fontana
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Pierangelo Geppetti
- Clinical Pharmacology Unit, Department of Health Sciences, University of Florence, Viale Pieraccini, 6, 50139, Florence, Italy.
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11
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Ogawa N, Kurokawa T, Mori Y. Sensing of redox status by TRP channels. Cell Calcium 2016; 60:115-22. [PMID: 26969190 DOI: 10.1016/j.ceca.2016.02.009] [Citation(s) in RCA: 315] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 02/17/2016] [Accepted: 02/17/2016] [Indexed: 11/17/2022]
Abstract
Cellular redox status is maintained by the balance between series of antioxidant systems and production of reactive oxygen/nitrogenous species. Cells utilize this redox balance to mediate diverse physiological functions. Transient receptor potential (TRP) channels are non-selective cation channels that act as biosensors for environmental and noxious stimuli, such as capsaicin and allicin, as well as changes in temperature and conditions inside the cell. TRP channels also have an emerging role as essential players in detecting cellular redox status to regulate cellular signals mediating physiological phenomena. Reactive species activate TRP channels either directly through oxidative amino acid modifications or indirectly through second messengers. For instance, TRPA1, TRPV1 and TRPC5 channels are directly activated by oxidizing agents through cysteine modification; whereas, TRPM2 channel is indirectly activated by production of ADP-ribose. One intriguing property of several TRP channels is susceptibility to both oxidizing and reducing stimuli, suggesting TRP channels could potentially act as a bidirectional sensor for detecting deviations in redox status. In this review, we discuss the unique chemical physiologies of redox sensitive TRP channels and their physiological significance in Ca(2+) signaling.
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Affiliation(s)
- Nozomi Ogawa
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Tatsuki Kurokawa
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Yasuo Mori
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan; Laboratory of Environmental Systems Biology, Department of Technology and Ecology, Hall of Global Environmental Studies, Kyoto University, Kyoto 615-8510, Japan.
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Liu BY, Lin YJ, Lee HF, Ho CY, Ruan T, Kou YR. Menthol suppresses laryngeal C-fiber hypersensitivity to cigarette smoke in a rat model of gastroesophageal reflux disease: the role of TRPM8. J Appl Physiol (1985) 2014; 118:635-45. [PMID: 25539933 DOI: 10.1152/japplphysiol.00717.2014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Patients with gastroesophageal reflux disease (GERD) display enhanced laryngeal reflex reactivity to stimuli that may be due to sensitization of the laryngeal C-fibers by acid and pepsin. Menthol, a ligand of transient receptor potential melastatin-8 (TRPM8), relieves throat irritation. However, the possibility that GERD induces laryngeal C-fiber hypersensitivity to cigarette smoke (CS) and that menthol suppresses this event has not been investigated. We delivered CS into functionally isolated larynxes of 160 anesthetized rats. Laryngeal pH 5-pepsin treatment, but not pH 5-denatured pepsin, augmented the apneic response to CS, which was blocked by denervation or perineural capsaicin treatment (a procedure that blocks the conduction of C fibers) of the superior laryngeal nerves. This augmented apnea was partially attenuated by capsazepine [an transient receptor potential vanilloid 1 (TRPV1) antagonist], SB-366791 (a TRPV1 antagonist), and HC030031 [a transient receptor potential ankyrin 1 (TRPA1) antagonist] and was completely prevented by a combination of TRPV1 and TRPA1 antagonists. Local application of menthol significantly suppressed the augmented apnea and this effect was reversed by pretreatment with AMTB (a TRPM8 antagonist). Our electrophysiological studies consistently revealed that laryngeal pH 5-pepsin treatment increased the sensitivity of laryngeal C-fibers to CS. Likewise, menthol suppressed this laryngeal C-fiber hypersensitivity and its effect could be reversed by pretreatment with AMTB. Our results suggest that laryngeal pH 5-pepsin treatment increases sensitivity to CS of both TRPV1 and TRPA1, which are presumably located at the terminals of laryngeal C-fibers. This sensory sensitization leads to enhanced laryngeal reflex reactivity and augmentation of the laryngeal C-fiber responses to CS, which can be suppressed by menthol acting via TRPM8.
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Affiliation(s)
- Bi-Yu Liu
- Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yu-Jung Lin
- Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Hung-Fu Lee
- Department of Neurosurgery, Cheng Hsin General Hospital, Taipei, Taiwan
| | - Ching-Yin Ho
- Department of Otolaryngology, Taipei Veteran General Hospital, Taipei, Taiwan; Department of Otolaryngology, National Yang-Ming University, Taipei, Taiwan; and
| | - Ting Ruan
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Yu Ru Kou
- Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan;
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Human TRPM8 and TRPA1 pain channels, including a gene variant with increased sensitivity to agonists (TRPA1 R797T), exhibit differential regulation by SRC-tyrosine kinase inhibitor. Biosci Rep 2014; 34:BSR20140061. [PMID: 24975826 PMCID: PMC4122973 DOI: 10.1042/bsr20140061] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
TRPM8 (transient receptor potential M8) and TRPA1 (transient receptor potential A1) are cold-temperature-sensitive nociceptors expressed in sensory neurons but their behaviour in neuronal cells is poorly understood. Therefore DNA expression constructs containing human TRPM8 or TRPA1 cDNAs were transfected into HEK (human embryonic kidney cells)-293 or SH-SY5Y neuroblastoma cells and G418 resistant clones analysed for effects of agonists and antagonists on intracellular Ca2+ levels. Approximately 51% of HEK-293 and 12% of SH-SY5Y cell clones expressed the transfected TRP channel. TRPM8 and TRPA1 assays were inhibited by probenecid, indicating the need to avoid this agent in TRP channel studies. A double-residue mutation in ICL-1 (intracellular loop-1) of TRPM8 (SV762,763EL, mimicking serine phosphorylation) or one in the C-terminal tail region (FK1045,1046AG, a lysine knockout) retained sensitivity to agonists (WS 12, menthol) and antagonist {AMTB [N-(3-Aminopropyl)-2-[(3-methylphenyl)methoxy]-N-(2-thienylmethyl)benzamide]}. SNP (single nucleotide polymorphism) variants in TRPA1 ICL-1 (R797T, S804N) and TRPA1 fusion protein containing C-terminal (His)10 retained sensitivity to agonists (cinnamaldehyde, allyl-isothiocyanate, carvacrol, eugenol) and antagonists (HC-030031, A967079). One SNP variant, 797T, possessed increased sensitivity to agonists. TRPA1 became repressed in SH-SY5Y clones but was rapidly rescued by Src-family inhibitor PP2 [4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine]. Conversely, TRPM8 in SH-SY5Y cells was inhibited by PP2. Further studies utilizing SH-SY5Y may identify structural features of TRPA1 and TRPM8 involved in conferring differential post-translational regulation. Transient receptor potential channels M8 and A1 sense the cellular environment and activate entry of Ca2+ into the cytoplasm. We identified a TRPA1 (transient receptor potential A1) variant with increased sensitivity and differential modulation of channels by a tyrosine kinase inhibitor in neuroblastoma cells.
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Ruan T, Lin YJ, Hsu TH, Lu SH, Jow GM, Kou YR. Sensitization by pulmonary reactive oxygen species of rat vagal lung C-fibers: the roles of the TRPV1, TRPA1, and P2X receptors. PLoS One 2014; 9:e91763. [PMID: 24699274 PMCID: PMC3974698 DOI: 10.1371/journal.pone.0091763] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 02/13/2014] [Indexed: 11/18/2022] Open
Abstract
Sensitization of vagal lung C-fibers (VLCFs) induced by mediators contributes to the pathogenesis of airway hypersensitivity, which is characterized by exaggerated sensory and reflex responses to stimulants. Reactive oxygen species (ROS) are mediators produced during airway inflammation. However, the role of ROS in VLCF-mediated airway hypersensitivity has remained elusive. Here, we report that inhalation of aerosolized 0.05% H2O2 for 90 s potentiated apneic responses to intravenous capsaicin (a TRPV1 receptor agonist), α,β-methylene-ATP (a P2X receptor agonist), and phenylbiguanide (a 5-HT3 receptor agonist) in anesthetized rats. The apneic responses to these three stimulants were abolished by vagatomy or by perivagal capsaicin treatment, a procedure that blocks the neural conduction of VLCFs. The potentiating effect of H2O2 on the apneic responses to these VLCF stimulants was prevented by catalase (an enzyme that degrades H2O2) and by dimethylthiourea (a hydroxyl radical scavenger). The potentiating effect of H2O2 on the apneic responses to capsaicin was attenuated by HC-030031 (a TRPA1 receptor antagonist) and by iso-pyridoxalphosphate-6-azophenyl-2',5'-disulphonate (a P2X receptor antagonist). The potentiating effect of H2O2 on the apneic responses to α,β-methylene-ATP was reduced by capsazepine (a TRPV1 receptor antagonist), and by HC-030031. The potentiating effect of H2O2 on the apneic responses to phenylbiguanide was totally abolished when all three antagonists were combined. Consistently, our electrophysiological studies revealed that airway delivery of aerosolized 0.05% H2O2 for 90 s potentiated the VLCF responses to intravenous capsaicin, α,β-methylene-ATP, and phenylbiguanide. The potentiating effect of H2O2 on the VLCF responses to phenylbiguanide was totally prevented when all antagonists were combined. Inhalation of 0.05% H2O2 indeed increased the level of ROS in the lungs. These results suggest that 1) increased lung ROS sensitizes VLCFs, which leads to exaggerated reflex responses in rats and 2) the TRPV1, TRPA1, and P2X receptors are all involved in the development of this airway hypersensitivity.
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Affiliation(s)
- Ting Ruan
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
- Department of Physiology, School of Medicine, Chung Shan Medical University, Taichung, Taiwan
| | - Yu-Jung Lin
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Tien-Huan Hsu
- Department of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan
| | - Shing-Hwa Lu
- Department of Urology, Taipei City Hospital, Zhong-Xiao Branch, Taipei, Taiwan
| | - Guey-Mei Jow
- School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Yu Ru Kou
- Department of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
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Lin YJ, Hsu HH, Ruan T, Kou YR. Mediator mechanisms involved in TRPV1, TRPA1 and P2X receptor-mediated sensory transduction of pulmonary ROS by vagal lung C-fibers in rats. Respir Physiol Neurobiol 2013; 189:1-9. [PMID: 23832015 DOI: 10.1016/j.resp.2013.06.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 06/18/2013] [Accepted: 06/24/2013] [Indexed: 12/13/2022]
Abstract
We investigated the mediator mechanisms involved in the sensory transduction of pulmonary reactive oxygen species (ROS) by vagal lung C-fibers in anesthetized rats. Airway challenge of aerosolized H₂O₂ (0.4%) stimulated these afferent fibers. The H₂O₂-induced responses were reduced by a cyclooxygenase inhibitor or ATP scavengers and also attenuated by an antagonist of TRPV1, TRPA1 or P2X receptors. The suppressive effect of the cyclooxygenase inhibitor was not affected by a combined treatment with the TRPV1 or TRPA1 antagonist, but was amplified by a combined treatment with the P2X antagonists. The suppressive effect of ATP scavengers was not affected by a combined treatment with the P2X antagonist, but was amplified by a combined treatment with the TRPV1 or TRPA1 antagonist. Thus, the actions of cyclooxygenase metabolites are mediated through the functioning of the TRPV1 and TRPA1 receptors, whereas the action of ATP is mediated through the functioning of P2X receptors.
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Affiliation(s)
- Yu-Jung Lin
- Institute of Physiology, School of Medicine, National Yang-Ming University, Taipei, Taiwan
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