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Wang N, Peng YJ, Kang W, Hildreth M, Prabhakar NR, Nanduri J. Transcriptomic Analysis of Postnatal Rat Carotid Body Development. Genes (Basel) 2024; 15:302. [PMID: 38540361 PMCID: PMC10970570 DOI: 10.3390/genes15030302] [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: 02/06/2024] [Revised: 02/13/2024] [Accepted: 02/14/2024] [Indexed: 06/14/2024] Open
Abstract
The carotid body (CB), located bilaterally at the carotid artery bifurcations, is the primary sensory organ for monitoring arterial blood O2 levels. Carotid bodies are immature at birth, exhibiting low sensitivity to hypoxia, and become more sensitive with maturation during the first few weeks of neonatal life. To understand the molecular basis for the postnatal developmental hypoxic responses of CB, we isolated CBs from 5-day and 21-day-old Sprague-Dawley rats and performed RNA sequencing, which allows comprehensive analysis of gene expression. Differentially expressed genes (DEGs) were generated using Edge R, while functional enrichment analysis was performed using gene-set enrichment analysis (GSEA). Analysis of RNA-Seq data showed 2604 DEGs of the total 12,696 genes shared between neonates and adults. Of the 2604 DEGs, 924 genes were upregulated, and 1680 genes were downregulated. Further analysis showed that genes related to oxidative phosphorylation (Ox/phos) and hypoxia-signaling pathways were significantly upregulated in neonatal CBs compared to adult CBs, suggesting a possible link to differential developmental hypoxic responses seen in CB. Genes related to cytokine signaling (INFγ and TNFα) and transcription factors (CREB and NFΚB) mediated pathways were enriched in adult CBs, suggesting that expression of these pathways may be linked to developmental regulation. The RNA-Seq results were verified by analyzing mRNA changes in selected genes by qRT-PCR. Our results of enrichment analysis of biological pathways offer valuable insight into CB hypoxic sensing responses related to the development process.
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Affiliation(s)
- Ning Wang
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, The University of Chicago, Chicago, IL 60637, USA
| | - Ying-Jie Peng
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, The University of Chicago, Chicago, IL 60637, USA
| | - Wenjun Kang
- Center for Research Informatics, The University of Chicago, Chicago, IL 60637, USA
| | - Matthew Hildreth
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, The University of Chicago, Chicago, IL 60637, USA
| | - Nanduri R. Prabhakar
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, The University of Chicago, Chicago, IL 60637, USA
| | - Jayasri Nanduri
- Institute for Integrative Physiology and Center for Systems Biology of O2 Sensing, The University of Chicago, Chicago, IL 60637, USA
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Drug-Like Small Molecule HSP27 Functional Inhibitor Sensitizes Lung Cancer Cells to Gefitinib or Cisplatin by Inducing Altered Cross-Linked Hsp27 Dimers. Pharmaceutics 2021; 13:pharmaceutics13050630. [PMID: 33925114 PMCID: PMC8145107 DOI: 10.3390/pharmaceutics13050630] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/18/2021] [Accepted: 04/21/2021] [Indexed: 11/17/2022] Open
Abstract
Relationships between heat shock protein 27 (HSP27) and cancer aggressiveness, metastasis, drug resistance, and poor patient outcomes in various cancer types including non-small cell lung cancer (NSCLC) were reported, and inhibition of HSP27 expression is suggested to be a possible strategy for cancer therapy. Unlike HSP90 or HSP70, HSP27 does not have an ATP-binding pocket, and no effective HSP27 inhibitors have been identified. Previously, NSCLC cancer cells were sensitized to radiation and chemotherapy when co-treated with small molecule HSP27 functional inhibitors such as zerumbone (ZER), SW15, and J2 that can induce abnormal cross-linked HSP27 dimer. In this study, cancer inhibition effects of NA49, a chromenone compound with better solubility, longer circulation time, and less toxicity than J2, were examined in combination with anticancer drugs such as cisplatin and gefitinib in NSCLC cell lines. When the cytotoxic drug cisplatin was treated in combination with NA49 in epidermal growth factor receptors (EGFRs) WT cell lines, sensitization was induced in an HSP27 expression-dependent manner. With gefitinib treatment, NA49 showed increased combination effects in both EGFR WT and Mut cell lines, also with HSP27 expression-dependent patterns. Moreover, NA49 induced sensitization in EGFR Mut cells with a secondary mutation of T790M when combined with gefitinib. Augmented tumor growth inhibition was shown with the combination of cisplatin or gefitinib and NA49 in nude mouse xenograft models. These results suggest the combination of HSP27 inhibitor NA49 and anticancer agents as a candidate for overcoming HSP27-mediated drug resistance in NSCLC patients.
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Abstract
SIGNIFICANCE Voltage-gated K+ channels are a large family of K+-selective ion channel protein complexes that open on membrane depolarization. These K+ channels are expressed in diverse tissues and their function is vital for numerous physiological processes, in particular of neurons and muscle cells. Potentially reversible oxidative regulation of voltage-gated K+ channels by reactive species such as reactive oxygen species (ROS) represents a contributing mechanism of normal cellular plasticity and may play important roles in diverse pathologies including neurodegenerative diseases. RECENT ADVANCES Studies using various protocols of oxidative modification, site-directed mutagenesis, and structural and kinetic modeling provide a broader phenomenology and emerging mechanistic insights. CRITICAL ISSUES Physicochemical mechanisms of the functional consequences of oxidative modifications of voltage-gated K+ channels are only beginning to be revealed. In vivo documentation of oxidative modifications of specific amino-acid residues of various voltage-gated K+ channel proteins, including the target specificity issue, is largely absent. FUTURE DIRECTIONS High-resolution chemical and proteomic analysis of ion channel proteins with respect to oxidative modification combined with ongoing studies on channel structure and function will provide a better understanding of how the function of voltage-gated K+ channels is tuned by ROS and the corresponding reducing enzymes to meet cellular needs.
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Affiliation(s)
- Nirakar Sahoo
- 1 Department of Biophysics, Center for Molecular Biomedicine, Friedrich Schiller University Jena and Jena University Hospital , Jena, Germany
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De Caro R, Macchi V, Sfriso MM, Porzionato A. Structural and neurochemical changes in the maturation of the carotid body. Respir Physiol Neurobiol 2013; 185:9-19. [DOI: 10.1016/j.resp.2012.06.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2012] [Revised: 05/16/2012] [Accepted: 06/08/2012] [Indexed: 02/07/2023]
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Carroll JL, Kim I. Carotid chemoreceptor "resetting" revisited. Respir Physiol Neurobiol 2012; 185:30-43. [PMID: 22982216 DOI: 10.1016/j.resp.2012.09.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/03/2012] [Accepted: 09/06/2012] [Indexed: 12/16/2022]
Abstract
Carotid body (CB) chemoreceptors transduce low arterial O(2) tension into increased action potential activity on the carotid sinus nerves, which contributes to resting ventilatory drive, increased ventilatory drive in response to hypoxia, arousal responses to hypoxia during sleep, upper airway muscle activity, blood pressure control and sympathetic tone. Their sensitivity to O(2) is low in the newborn and increases during the days or weeks after birth to reach adult levels. This postnatal functional maturation of the CB O(2) response has been termed "resetting" and it occurs in every mammalian species studied to date. The O(2) environment appears to play a key role; the fetus develops in a low O(2) environment throughout gestation and initiation of CB "resetting" after birth is modulated by the large increase in arterial oxygen tension occurring at birth. Although numerous studies have reported age-related changes in various components of the O(2) transduction cascade, how the O(2) environment shapes normal CB prenatal development and postnatal "resetting" remains unknown. Viewing CB "resetting" as environment-driven (developmental) phenotypic plasticity raises important mechanistic questions that have received little attention. This review examines what is known (and not known) about mechanisms of CB functional maturation, with a focus on the role of the O(2) environment.
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Affiliation(s)
- John L Carroll
- Division of Pediatric Pulmonary Medicine, Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children's Hospital, 1 Children's Way, Little Rock, AR 72202, United States.
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Kim D. K(+) channels in O(2) sensing and postnatal development of carotid body glomus cell response to hypoxia. Respir Physiol Neurobiol 2012; 185:44-56. [PMID: 22801091 DOI: 10.1016/j.resp.2012.07.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 07/06/2012] [Accepted: 07/09/2012] [Indexed: 12/25/2022]
Abstract
The sensitivity of carotid body chemoreceptors to hypoxia is low just after birth and increases over the first few weeks of the postnatal period. At present, it is believed that the hypoxia-induced excitation of carotid body glomus cells begins with the inhibition of the outward K(+) current via one or more O(2) sensors. Although the nature of the O(2) sensors and their signals that inhibit the K(+) current are not well defined, studies suggest that the postnatal maturation of the glomus cell response to hypoxia is largely due to the increased sensitivity of K(+) channels to hypoxia. As K(V), BK and TASK channels that are O(2)-sensitive contribute to the K(+) current, it is important to identify the O(2) sensor and the signaling molecule for each of these K(+) channels. Various O(2) sensors (mitochondrial hemeprotein, hemeoxygenase-2, NADPH oxidase) and associated signals have been proposed to mediate the inhibition of K(+) channels by hypoxia. Studies suggest that a mitochondrial hemeprotein is likely to serve as an O(2) sensor for K(+) channels, particularly for TASK, and that multiple signals may be involved. Thus, changes in the sensitivity of the mitochondrial O(2) sensor to hypoxia, the sensitivity of K(+) channels to signals generated by mitochondria, and/or the expression levels of K(+) channels are likely to account for the postnatal maturation of O(2) sensing by glomus cells.
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Affiliation(s)
- Donghee Kim
- Department of Physiology and Biophysics, The Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064, United States.
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Vandenberg JI, Perry MD, Perrin MJ, Mann SA, Ke Y, Hill AP. hERG K+ Channels: Structure, Function, and Clinical Significance. Physiol Rev 2012; 92:1393-478. [DOI: 10.1152/physrev.00036.2011] [Citation(s) in RCA: 463] [Impact Index Per Article: 38.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The human ether-a-go-go related gene (hERG) encodes the pore-forming subunit of the rapid component of the delayed rectifier K+ channel, Kv11.1, which are expressed in the heart, various brain regions, smooth muscle cells, endocrine cells, and a wide range of tumor cell lines. However, it is the role that Kv11.1 channels play in the heart that has been best characterized, for two main reasons. First, it is the gene product involved in chromosome 7-associated long QT syndrome (LQTS), an inherited disorder associated with a markedly increased risk of ventricular arrhythmias and sudden cardiac death. Second, blockade of Kv11.1, by a wide range of prescription medications, causes drug-induced QT prolongation with an increase in risk of sudden cardiac arrest. In the first part of this review, the properties of Kv11.1 channels, including biogenesis, trafficking, gating, and pharmacology are discussed, while the second part focuses on the pathophysiology of Kv11.1 channels.
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Affiliation(s)
- Jamie I. Vandenberg
- Mark Cowley Lidwill Research Programme in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, New South Wales, Australia; and University of Ottawa Heart Institute, Ottawa, Canada
| | - Matthew D. Perry
- Mark Cowley Lidwill Research Programme in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, New South Wales, Australia; and University of Ottawa Heart Institute, Ottawa, Canada
| | - Mark J. Perrin
- Mark Cowley Lidwill Research Programme in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, New South Wales, Australia; and University of Ottawa Heart Institute, Ottawa, Canada
| | - Stefan A. Mann
- Mark Cowley Lidwill Research Programme in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, New South Wales, Australia; and University of Ottawa Heart Institute, Ottawa, Canada
| | - Ying Ke
- Mark Cowley Lidwill Research Programme in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, New South Wales, Australia; and University of Ottawa Heart Institute, Ottawa, Canada
| | - Adam P. Hill
- Mark Cowley Lidwill Research Programme in Cardiac Electrophysiology, Victor Chang Cardiac Research Institute, Sydney, New South Wales, Australia; St Vincent's Clinical School, University of New South Wales, New South Wales, Australia; and University of Ottawa Heart Institute, Ottawa, Canada
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Niane LM, Donnelly DF, Joseph V, Bairam A. Ventilatory and carotid body chemoreceptor responses to purinergic P2X receptor antagonists in newborn rats. J Appl Physiol (1985) 2010; 110:83-94. [PMID: 21051571 DOI: 10.1152/japplphysiol.00871.2010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Adenosine triphosphate, acting through purinergic P2X receptors, has been shown to stimulate ventilation and increase carotid body chemoreceptor activity in adult rats. However, its role during postnatal development of the ventilatory response to hypoxia is yet unknown. Using whole body plethysmography, we measured ventilation in normoxia and in moderate hypoxia (12% fraction of inspired O₂, 20 min) before and after intraperitoneal injection of suramin (P2X₂ and P2X₃ receptor antagonist, 40 mg/kg) in 4-, 7-, 12-, and 21-day-old rats. Suramin reduced baseline breathing (∼20%) and the response to hypoxia (∼30%) in all rats, with a relatively constant effect across ages. We then tested the effect of the specific P2X₃ antagonist, A-317491 (150 mg/kg), in rats aged 4, 7, and 21 days. As with suramin, A-317491 reduced baseline ventilation (∼55%) and the hypoxic response (∼40%) at all ages studied. Single-unit carotid body chemoreceptor activity was recorded in vitro in 4-, 7-, and 21-day-old rats. Suramin (100 μM) and A-317491 (10 μM) significantly depressed the sinus nerve chemosensory discharge rate (∼80%) in normoxia (Po₂ ∼150 Torr) and hypoxia (Po₂ ∼60 Torr), and this decrease was constant across ages. We conclude that, in newborn rats, P2X purinergic receptors are involved in the regulation of breathing under basal and hypoxic condition, and P2X₃-containing receptors play a major role in carotid body function. However, these effects are not age dependent within the age range studied.
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Affiliation(s)
- Lalah M Niane
- Unité de Recherche en Périnatologie, Centre Hospitalier Universitaire de Québec, Hôpital Saint-François d’Assise, Département de Pédiatrie, Université Laval, Québec, Canada
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Niane L, Joseph V, Bairam A. Role of cholinergic-nicotinic receptors on hypoxic chemoreflex during postnatal development in rats. Respir Physiol Neurobiol 2009; 169:323-32. [DOI: 10.1016/j.resp.2009.09.014] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 09/28/2009] [Accepted: 09/29/2009] [Indexed: 11/28/2022]
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Gauda EB, Carroll JL, Donnelly DF. Developmental maturation of chemosensitivity to hypoxia of peripheral arterial chemoreceptors--invited article. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2009; 648:243-55. [PMID: 19536487 DOI: 10.1007/978-90-481-2259-2_28] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Peripheral arterial chemoreceptors, particularly the carotid body chemoreceptors, are the primary sites for the detection of hypoxia and reflexly increase ventilatory drive and behavioral arousal during hypoxic or asphyxial events. Newborn infants are at risk for hypoxic and asphyxial events during sleep, yet, the strength of the chemoreceptor responses is low or absent at birth and then progressively increases with early postnatal development. This review summarizes the available data showing that even though the "oxygen sensor" in the glomus cells has not been unequivocally identified, it is clear that development affects many of the other properties of the chemoreceptor unit (glomus cell, afferent nerve fibers and neurotransmitter profile at the synapse) that are necessary and essential for the propagation of the "sensing" response, and exposure to hypoxia, hyperoxia and nicotine can modify normal development of each of the components leading to altered peripheral chemoreceptor responses.
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Affiliation(s)
- Estelle B Gauda
- Department of Pediatrics, Division of Neonatology, Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA.
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Nanduri J, Wang N, Bergson P, Yuan G, Ficker E, Prabhakar NR. Mitochondrial reactive oxygen species mediate hypoxic down-regulation of hERG channel protein. Biochem Biophys Res Commun 2008; 373:309-14. [DOI: 10.1016/j.bbrc.2008.06.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2008] [Accepted: 06/06/2008] [Indexed: 11/17/2022]
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Pawar A, Peng YJ, Jacono FJ, Prabhakar NR. Comparative analysis of neonatal and adult rat carotid body responses to chronic intermittent hypoxia. J Appl Physiol (1985) 2008; 104:1287-94. [PMID: 18187605 DOI: 10.1152/japplphysiol.00644.2007] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous studies suggest that carotid body responses to long-term changes in environmental oxygen differ between neonates and adults. In the present study we tested the hypothesis that the effects of chronic intermittent hypoxia (CIH) on the carotid body differ between neonates and adult rats. Experiments were performed on neonatal (1-10 days) and adult (6-8 wk) males exposed either to CIH (9 episodes/h; 8 h/day) or to normoxia. Sensory activity was recorded from ex vivo carotid bodies. CIH augmented the hypoxic sensory response (HSR) in both groups. The magnitude of CIH-evoked hypoxic sensitization was significantly greater in neonates than in adults. Seventy-two episodes of CIH were sufficient to evoke hypoxic sensitization in neonates, whereas as many as 720 CIH episodes were required in adults, suggesting that neonatal carotid bodies are more sensitive to CIH than adult carotid bodies. CIH-induced hypoxic sensitization was reversed in adult rats after reexposure to 10 days of normoxia, whereas the effects of neonatal CIH persisted into adult life (2 mo). Acute intermittent hypoxia (IH) evoked sensory long-term facilitation of the carotid body activity (sensory LTF, i.e., increased baseline neural activity following acute IH) in CIH-exposed adults but not in neonates. The effects of CIH were associated with hyperplasia of glomus cells in neonatal but not in adult carotid bodies. These observations demonstrate that responses to CIH differ between neonates and adults with regard to the magnitude of sensitization of HSR, susceptibility to CIH, induction of sensory LTF, reversibility of the responses, and morphological remodeling of the chemoreceptor tissue.
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Affiliation(s)
- Anita Pawar
- Center for Systems Biology, Department of Medicine, The University of Chicago, 5841 S. Maryland MC, Chicago, IL 60637, USA
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Wasicko MJ, Breitwieser GE, Kim I, Carroll JL. Postnatal development of carotid body glomus cell response to hypoxia. Respir Physiol Neurobiol 2006; 154:356-71. [PMID: 16466972 DOI: 10.1016/j.resp.2006.01.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Revised: 01/10/2006] [Accepted: 01/11/2006] [Indexed: 10/25/2022]
Abstract
This study examines developmental changes in CB glomus cell depolarization, intracellular calcium ([Ca(2+)](i)) and the magnitude of an O(2)-sensitive background ionic conductance that may play roles in the postnatal increase in oxygen sensitivity of glomus cells isolated from rats of 1-3 days and 11-14 days postnatal age. Using fura-2 and perforated patch whole cell recordings, we simultaneously measured [Ca(2+)](i) and membrane potential (E(m)) during normoxia and hypoxia. Resting E(m) in normoxia was similar at both ages. Hypoxia caused a larger E(m) depolarization and correspondingly larger [Ca(2+)](i) response in glomus cells from 11- to 14-day-old rats compared to 1-3-day-old rats. E(m) and [Ca(2+)](i) responses to 40mM K(+) were identical between the two age groups. Under normoxic conditions both age groups had similar background conductances. Under anoxic conditions (at resting membrane potential) background K(+) conductance decreased significantly more in cells from 11- to 14-day-old rats compared to cells from 1- to 3-day-old rats. Glomus cells from newborns therefore have less O(2)-sensitive background K(+) conductance. These results support the hypothesis that postnatal maturation of glomus cell O(2) sensitivity involves developmental regulation of the expression and/or O(2)-sensitivity of background ionic conductances.
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Affiliation(s)
- M J Wasicko
- Johns Hopkins University School of Medicine, Johns Hopkins Children's Center, Baltimore, MD, United States
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Carroll JL, Kim I. Postnatal development of carotid body glomus cell O2 sensitivity. Respir Physiol Neurobiol 2005; 149:201-15. [PMID: 15886071 DOI: 10.1016/j.resp.2005.04.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Revised: 04/07/2005] [Accepted: 04/07/2005] [Indexed: 01/17/2023]
Abstract
In mammals, the main sensors of arterial oxygen level are the carotid chemoreceptors, which exhibit low sensitivity to hypoxia at birth and become more sensitive over the first few days or weeks of life. This postnatal increase in hypoxia sensitivity of the arterial chemoreceptors, termed "resetting", remains poorly understood. In the carotid body, hypoxia is transduced by glomus cells, which are secretory sensory neurons that respond to hypoxia at higher P(O2) levels than non-chemoreceptor cell types. Maturation or resetting of carotid body O2 sensitivity potentially involves numerous aspects of the O2 transduction cascade at the glomus cell level, including glomus cell neurotransmitter secretion, neuromodulator function, neurotransmitter receptor expression, glomus cell depolarization in response to hypoxia, [Ca2+]i responses to hypoxia, K+ and Ca2+ channel O2 sensitivity and K+ channel expression. However, although progress has been made in the understanding of carotid body development, the precise mechanisms underlying postnatal maturation of these numerous aspects of chemotransduction remain obscure.
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Affiliation(s)
- John L Carroll
- University of Arkansas for Medical Sciences College of Medicine, Department of Pediatrics, Pediatric Respiratory Medicine Section, Arkansas Children's Hospital, Little Rock, AR 72202, USA.
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Yu Y, Yu BP, Wang FQ. Expression of ether-a-go-go-related gene in gastrointestinal tract of normal CD1 mice. Shijie Huaren Xiaohua Zazhi 2005; 13:1842-1845. [DOI: 10.11569/wcjd.v13.i15.1842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the expression of ether-a-go-go-related gene (ERG) mRNA and protein and its different distributions in the gastrointestinal tract of CD1 mice.
METHODS: The expression of ERG K+ current related protein was examined by immunohistochemistry and the expression of ERG mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR) and in situ hybridization in the tissues of stomach, jejunum, ileum and colon from adult CD1 mice. Then the distribution of ERG was analyzed.
RESULTS: ERG was positively expressed in all the tissues of stomach, jejunum, ileum and colon. The positive cells mainly distributed in the muscular layer. A small number of positive cells distributed in the mucosa and chorion. The levels of ERG expression in stomach and colon were significantly higher than those in jejunum and ileum (4.30±0.95, 3.60±0.70 vs2.70±0.82, 2.30±1.06; P<0.05).
CONCLUSION: ERG is expressed in the gastrointestinal tract of CD1 mice. Furthermore, the expression is differential at different sites.
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