1
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Bjork S, Jain D, Marliere MH, Predescu SA, Mokhlesi B. Obstructive Sleep Apnea, Obesity Hypoventilation Syndrome, and Pulmonary Hypertension: A State-of-the-Art Review. Sleep Med Clin 2024; 19:307-325. [PMID: 38692755 DOI: 10.1016/j.jsmc.2024.02.009] [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] [Indexed: 05/03/2024]
Abstract
The pathophysiological interplay between sleep-disordered breathing (SDB) and pulmonary hypertension (PH) is complex and can involve a variety of mechanisms by which SDB can worsen PH. These mechanistic pathways include wide swings in intrathoracic pressure while breathing against an occluded upper airway, intermittent and/or sustained hypoxemia, acute and/or chronic hypercapnia, and obesity. In this review, we discuss how the downstream consequences of SDB can adversely impact PH, the challenges in accurately diagnosing and classifying PH in the severely obese, and review the limited literature assessing the effect of treating obesity, obstructive sleep apnea, and obesity hypoventilation syndrome on PH.
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Affiliation(s)
- Sarah Bjork
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Rush University Medical Center, 1750 W. Harrison Street, Jelke 297, Chicago, IL 60612, USA
| | - Deepanjali Jain
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Rush University Medical Center, 1750 W. Harrison Street, Jelke 297, Chicago, IL 60612, USA
| | - Manuel Hache Marliere
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Rush University Medical Center, 1750 W. Harrison Street, Jelke 297, Chicago, IL 60612, USA
| | - Sanda A Predescu
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Rush University Medical Center, 1750 W. Harrison Street, Jelke 297, Chicago, IL 60612, USA
| | - Babak Mokhlesi
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Rush University Medical Center, 1750 W. Harrison Street, Jelke 297, Chicago, IL 60612, USA.
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2
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Phelan DE, Reddan B, Shigemura M, Sznajder JI, Crean D, Cummins EP. Orphan Nuclear Receptor Family 4A (NR4A) Members NR4A2 and NR4A3 Selectively Modulate Elements of the Monocyte Response to Buffered Hypercapnia. Int J Mol Sci 2024; 25:2852. [PMID: 38474099 PMCID: PMC10931687 DOI: 10.3390/ijms25052852] [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: 01/12/2024] [Revised: 02/19/2024] [Accepted: 02/22/2024] [Indexed: 03/14/2024] Open
Abstract
Hypercapnia occurs when the partial pressure of carbon dioxide (CO2) in the blood exceeds 45 mmHg. Hypercapnia is associated with several lung pathologies and is transcriptionally linked to suppression of immune and inflammatory signalling through poorly understood mechanisms. Here we propose Orphan Nuclear Receptor Family 4A (NR4A) family members NR4A2 and NR4A3 as potential transcriptional regulators of the cellular response to hypercapnia in monocytes. Using a THP-1 monocyte model, we investigated the sensitivity of NR4A family members to CO2 and the impact of depleting NR4A2 and NR4A3 on the monocyte response to buffered hypercapnia (10% CO2) using RNA-sequencing. We observed that NR4A2 and NR4A3 are CO2-sensitive transcription factors and that depletion of NR4A2 and NR4A3 led to reduced CO2-sensitivity of mitochondrial and heat shock protein (Hsp)-related genes, respectively. Several CO2-sensitive genes were, however, refractory to depletion of NR4A2 and NR4A3, indicating that NR4As regulate certain elements of the cellular response to buffered hypercapnia but that other transcription factors also contribute. Bioinformatic analysis of conserved CO2-sensitive genes implicated several novel putative CO2-sensitive transcription factors, of which the ETS Proto-Oncogene 1 Transcription Factor (ETS-1) was validated to show increased nuclear expression in buffered hypercapnia. These data give significant insights into the understanding of immune responses in patients experiencing hypercapnia.
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Affiliation(s)
- David E. Phelan
- School of Medicine, University College Dublin, Dublin 4, Ireland (B.R.)
- Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
| | - Ben Reddan
- School of Medicine, University College Dublin, Dublin 4, Ireland (B.R.)
- Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
| | - Masahiko Shigemura
- Division of Thoracic Surgery, Northwestern University, Chicago, IL 60611, USA;
| | - Jacob I. Sznajder
- Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA;
| | - Daniel Crean
- Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
- School of Veterinary Medicine, University College Dublin, Dublin 4, Ireland
| | - Eoin P. Cummins
- School of Medicine, University College Dublin, Dublin 4, Ireland (B.R.)
- Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
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3
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Grams KJ, Neumueller SE, Mouradian GC, Burgraff NJ, Hodges MR, Pan L, Forster HV. Mild and moderate chronic hypercapnia elicit distinct transcriptomic responses of immune function in cardiorespiratory nuclei. Physiol Genomics 2023; 55:487-503. [PMID: 37602394 PMCID: PMC11178267 DOI: 10.1152/physiolgenomics.00038.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 08/03/2023] [Accepted: 08/17/2023] [Indexed: 08/22/2023] Open
Abstract
Chronic hypercapnia (CH) is a hallmark of respiratory-related diseases, and the level of hypercapnia can acutely or progressively become more severe. Previously, we have shown time-dependent adaptations in steady-state physiology during mild (arterial Pco2 ∼55 mmHg) and moderate (∼60 mmHg) CH in adult goats, including transient (mild CH) or sustained (moderate CH) suppression of acute chemosensitivity suggesting limitations in adaptive respiratory control mechanisms as the level of CH increases. Changes in specific markers of glutamate receptor plasticity, interleukin-1ß, and serotonergic modulation within key nodes of cardiorespiratory control do not fully account for the physiological adaptations to CH. Here, we used an unbiased approach (bulk tissue RNA sequencing) to test the hypothesis that mild or moderate CH elicits distinct gene expression profiles in important brain stem regions of cardiorespiratory control, which may explain the contrasting responses to CH. Gene expression profiles from the brain regions validated the accuracy of tissue biopsy methodology. Differential gene expression analyses revealed greater effects of CH on brain stem sites compared with the medial prefrontal cortex. Mild CH elicited an upregulation of predominantly immune-related genes and predicted activation of immune-related pathways and functions. In contrast, moderate CH broadly led to downregulation of genes and predicted inactivation of cellular pathways related to the immune response and vascular function. These data suggest that mild CH leads to a steady-state activation of neuroinflammatory pathways within the brain stem, whereas moderate CH drives the opposite response. Transcriptional shifts in immune-related functions may underlie the cardiorespiratory network's capability to respond to acute, more severe hypercapnia when in a state of progressively increased CH.NEW & NOTEWORTHY Mild chronic hypercapnia (CH) broadly upregulated immune-related genes and a predicted activation of biological pathways related to immune cell activity and the overall immune response. In contrast, moderate CH primarily downregulated genes related to major histocompatibility complex signaling and vasculature function that led to a predicted inactivation of pathways involving the immune response and vascular endothelial function. The severity-dependent effect on immune responses suggests that neuroinflammation has an important role in CH and may be important in the maintenance of proper ventilatory responses to acute and chronic hypercapnia.
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Affiliation(s)
- Kirstyn J Grams
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Suzanne E Neumueller
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Gary C Mouradian
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Nicholas J Burgraff
- Center for Integrated Brain Research, Seattle Children's Research Institute, Seattle, Washington, United States
| | - Matthew R Hodges
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Lawrence Pan
- Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, United States
| | - Hubert V Forster
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States
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4
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Nevler A, Khalilieh S, Lavu H, Bowne W, Yeo CJ. Hypercapnic Tissue Gene Expression and Survival in Early-Stage Pancreatic Ductal Adenocarcinoma. J Am Coll Surg 2023; 236:913-922. [PMID: 36728372 DOI: 10.1097/xcs.0000000000000552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Pancreatic ductal adenocarcinoma (PDAC) is an aggressive and lethal cancer. Hypercapnic tumor microenvironments were previously shown to promote cancer chemoresistance. In this study, we aimed to investigate the impact of tissue hypercapnia on PDAC prognosis. STUDY DESIGN PDAC cancer-cell lines were cultured in normocapnic (5% CO 2 ) and hypercapnic conditions (10% CO 2 ). RNA was extracted, and whole-exome transcriptome was sequenced. Differentially expressed genes were identified and used to construct a "hypercapnic gene set." PDAC transcriptomic patient data from the Tumor Cancer Genome Atlas was used to calculate single-sample gene set enrichment scores based on each patient's tissue expression of the hypercapnic gene set. Tissue hypercapnic scores (HSs) in PDAC patients (TMN stages Ia-IIb) were determined and correlated with clinicopathological parameters and overall survival. RESULTS A cohort of 135 resected stage I-II PDAC patients were assessed in this study. The average age was 65 ± 11.0 years, and the male:female ratio was 74:61. Median overall survival was 19.5 ± 1.4 months. High HSs were associated with increased tumor stage (p < 0.05) and higher lymph-node ratio (p < 0.05). In active smokers, high HS also correlated with smoking pack-years (p < 0.05). Cox regression analysis revealed high HS to be an independent prognostic factor for overall survival (hazard ratio [HR] 2.66, p = 0.004), along with lymph-node ratio (HR 4.2, p = 0.002) and age at diagnosis (HR 2.63, p = 0.01). CONCLUSIONS The pancreatic tumor microenvironment plays an integral role in tumor aggressiveness, and our previous in vitro data suggest that hypercapnia promotes an aggressive, more resistant phenotype. Herein, we show that in early-stage pancreatic cancer, hypercapnic tissue signatures corresponded with a worse overall survival.
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Affiliation(s)
- Avinoam Nevler
- From the Jefferson Pancreas, Biliary, and Related Cancer Center, Department of Surgery, Thomas Jefferson University, Philadelphia, PA
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5
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Dada LA, Welch LC, Magnani ND, Ren Z, Han H, Brazee PL, Celli D, Flozak AS, Weng A, Herrerias MM, Kryvenko V, Vadász I, Runyan CE, Abdala-Valencia H, Shigemura M, Casalino-Matsuda SM, Misharin AV, Budinger GS, Gottardi CJ, Sznajder JI. Hypercapnia alters stroma-derived Wnt production to limit β-catenin signaling and proliferation in AT2 cells. JCI Insight 2023; 8:e159331. [PMID: 36626234 PMCID: PMC9977495 DOI: 10.1172/jci.insight.159331] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 01/05/2023] [Indexed: 01/11/2023] Open
Abstract
Persistent symptoms and radiographic abnormalities suggestive of failed lung repair are among the most common symptoms in patients with COVID-19 after hospital discharge. In mechanically ventilated patients with acute respiratory distress syndrome (ARDS) secondary to SARS-CoV-2 pneumonia, low tidal volumes to reduce ventilator-induced lung injury necessarily elevate blood CO2 levels, often leading to hypercapnia. The role of hypercapnia on lung repair after injury is not completely understood. Here - using a mouse model of hypercapnia exposure, cell lineage tracing, spatial transcriptomics, and 3D cultures - we show that hypercapnia limits β-catenin signaling in alveolar type II (AT2) cells, leading to their reduced proliferative capacity. Hypercapnia alters expression of major Wnts in PDGFRα+ fibroblasts from those maintaining AT2 progenitor activity toward those that antagonize β-catenin signaling, thereby limiting progenitor function. Constitutive activation of β-catenin signaling in AT2 cells or treatment of organoid cultures with recombinant WNT3A protein bypasses the inhibitory effects of hypercapnia. Inhibition of AT2 proliferation in patients with hypercapnia may contribute to impaired lung repair after injury, preventing sealing of the epithelial barrier and increasing lung flooding, ventilator dependency, and mortality.
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Affiliation(s)
- Laura A. Dada
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Lynn C. Welch
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Natalia D. Magnani
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Ziyou Ren
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Hyebin Han
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Patricia L. Brazee
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Diego Celli
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Annette S. Flozak
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Anthea Weng
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Mariana Maciel Herrerias
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Vitalii Kryvenko
- Justus Liebig University, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Department of Internal Medicine, Giessen, Germany
- The Cardio-Pulmonary Institute, Giessen, Germany
| | - István Vadász
- Justus Liebig University, Universities of Giessen and Marburg Lung Center, Member of the German Center for Lung Research, Department of Internal Medicine, Giessen, Germany
- The Cardio-Pulmonary Institute, Giessen, Germany
| | - Constance E. Runyan
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Hiam Abdala-Valencia
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Masahiko Shigemura
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | | | - Alexander V. Misharin
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - G.R. Scott Budinger
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Cara J. Gottardi
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
| | - Jacob I. Sznajder
- Pulmonary and Critical Care Medicine, Northwestern Feinberg School of Medicine, Chicago, Illinois, USA
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6
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Cummins EP, Bharat A, Sznajder JI, Vadász I. Editorial: Elevated Carbon Dioxide Sensing and Physiologic Effects. Front Physiol 2022; 13:894222. [PMID: 35574468 PMCID: PMC9092065 DOI: 10.3389/fphys.2022.894222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 03/22/2022] [Indexed: 11/21/2022] Open
Affiliation(s)
- Eoin P Cummins
- School of Medicine and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Ankit Bharat
- Division of Thoracic Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States.,Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Jacob I Sznajder
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - István Vadász
- Department of Internal Medicine, Member of the German Center for Lung Research (DZL), Justus Liebig University, Universities of Giessen and Marburg Lung Center (UGMLC), Giessen, Germany.,The Cardio-Pulmonary Institute (CPI), Giessen, Germany.,Institute for Lung Health (ILH), Giessen, Germany
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7
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Pawloski W, Komiyama T, Kougentakis C, Majumdar A, Fushman D. Site-Specific Detection and Characterization of Ubiquitin Carbamylation. Biochemistry 2022; 61:712-721. [PMID: 35380792 PMCID: PMC9173829 DOI: 10.1021/acs.biochem.2c00085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The physiological consequences of varying in vivo CO2 levels point to a general mechanism for CO2 to influence cellular homeostasis beyond regulating pH. Aside from a few instances where CO2 has been observed to cause post-translational protein modification, by forming long-lived carbamates, little is known about how transitory and ubiquitous carbamylation events could induce a physiological response. Ubiquitin is a versatile protein involved in a multitude of cellular signaling pathways as polymeric chains of various lengths formed through one of the seven lysines or N-terminal amine. Unique polyubiquitin (polyUb) compositions present recognition signals for specific ubiquitin-receptors which enables this one protein to be involved in many different cellular processes. Advances in proteomic methods have allowed the capture and identification of protein carbamates in vivo, and Ub was found carbamylated at lysines K48 and K33. This was shown to negatively regulate ubiquitin-mediated signaling by inhibiting polyUb chain formation. Here, we expand upon these observations by characterizing the carbamylation susceptibility for all Ub amines simultaneously. Using NMR methods which directly probe 15N resonances, we determined carbamylation rates under various environmental conditions and related them to the intrinsic pKas. Our results show that the relatively low pKas for half of the Ub amines are correlated with enhanced susceptibility to carbamylation under physiological conditions. Two of these carbamylated amines, not observed by chemical capture, appear to be physiologically relevant post-translational modifications. These findings point to a mechanism for varying the levels of CO2 due to intracellular localization, cellular stresses, and metabolism to affect certain polyUb-mediated signaling pathways.
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Affiliation(s)
- Westley Pawloski
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, Maryland 20742, United States
| | - Teppei Komiyama
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, Maryland 20742, United States
| | - Christos Kougentakis
- Department of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Ananya Majumdar
- Biomolecular NMR Center, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - David Fushman
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, Maryland 20742, United States
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8
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Rouka E, Gourgoulianni N, Lüpold S, Hatzoglou C, Gourgoulianis KI, Zarogiannis SG. Prediction and enrichment analyses of the Homo sapiens-Drosophila melanogaster COPD-related orthologs. Am J Physiol Regul Integr Comp Physiol 2021; 322:R77-R82. [PMID: 34877887 DOI: 10.1152/ajpregu.00092.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The significant similarities in airway epithelial cells between mammals and the fruit fly Drosophila melanogaster have rendered the latter an important model organism for studies of chronic inflammatory lung diseases. Focusing on the chronic obstructive pulmonary disease (COPD), we here mapped human gene orthologs associated with this disease in D. melanogaster to identify functionally equivalent genes for immediate, further screening with the fruit fly model. The DIOPT-DIST tool was accessed for the prediction of the COPD-associated orthologs between humans and Drosophila. Enrichment analyses with respect to pathways of the retrieved functional homologs were performed using the ToppFun and FlyMine tools, identifying 73 unique human genes as well as 438 fruit fly genes. The ToppFun analysis verified that the human gene list is associated with COPD phenotypes. Further, the FlyMine investigation highlighted that the Drosophila genes are functionally connected mainly with the 'ABC-family proteins mediated transport' and the 'beta-catenin independent WNT signaling pathway'. These results suggest an evolutionarily conserved role towards responses to inhaled toxicants and CO2 in both species. We reason that the predicted orthologous genes should be further studied in the Drosophila models of cigarette smoke-induced COPD.
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Affiliation(s)
- Erasmia Rouka
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Thessaly, BIOPOLIS, Larissa, Greece
| | - Natalia Gourgoulianni
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Stefan Lüpold
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Chrissi Hatzoglou
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Thessaly, BIOPOLIS, Larissa, Greece.,Department of Respiratory Medicine, Faculty of Medicine, School of Health Sciences, University of Thessaly, BIOPOLIS, Larissa, Greece
| | - Konstantinos I Gourgoulianis
- Department of Respiratory Medicine, Faculty of Medicine, School of Health Sciences, University of Thessaly, BIOPOLIS, Larissa, Greece
| | - Sotirios G Zarogiannis
- Department of Physiology, Faculty of Medicine, School of Health Sciences, University of Thessaly, BIOPOLIS, Larissa, Greece.,Department of Respiratory Medicine, Faculty of Medicine, School of Health Sciences, University of Thessaly, BIOPOLIS, Larissa, Greece
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9
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Kryvenko V, Vadász I. Mechanisms of Hypercapnia-Induced Endoplasmic Reticulum Dysfunction. Front Physiol 2021; 12:735580. [PMID: 34867444 PMCID: PMC8640499 DOI: 10.3389/fphys.2021.735580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 10/27/2021] [Indexed: 01/16/2023] Open
Abstract
Protein transcription, translation, and folding occur continuously in every living cell and are essential for physiological functions. About one-third of all proteins of the cellular proteome interacts with the endoplasmic reticulum (ER). The ER is a large, dynamic cellular organelle that orchestrates synthesis, folding, and structural maturation of proteins, regulation of lipid metabolism and additionally functions as a calcium store. Recent evidence suggests that both acute and chronic hypercapnia (elevated levels of CO2) impair ER function by different mechanisms, leading to adaptive and maladaptive regulation of protein folding and maturation. In order to cope with ER stress, cells activate unfolded protein response (UPR) pathways. Initially, during the adaptive phase of ER stress, the UPR mainly functions to restore ER protein-folding homeostasis by decreasing protein synthesis and translation and by activation of ER-associated degradation (ERAD) and autophagy. However, if the initial UPR attempts for alleviating ER stress fail, a maladaptive response is triggered. In this review, we discuss the distinct mechanisms by which elevated CO2 levels affect these molecular pathways in the setting of acute and chronic pulmonary diseases associated with hypercapnia.
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Affiliation(s)
- Vitalii Kryvenko
- Department of Internal Medicine, Justus Liebig University Giessen, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany.,The Cardio-Pulmonary Institute (CPI), Giessen, Germany
| | - István Vadász
- Department of Internal Medicine, Justus Liebig University Giessen, Universities of Giessen and Marburg Lung Center (UGMLC), Member of the German Center for Lung Research (DZL), Giessen, Germany.,The Cardio-Pulmonary Institute (CPI), Giessen, Germany.,Institute for Lung Health (ILH), Giessen, Germany
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10
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Abstract
Since the industrial revolution, air pollution has become a major problem causing several health problems involving the airways as well as the cardiovascular, reproductive, or neurological system. According to the WHO, about 3.6 million deaths every year are related to inhalation of polluted air, specifically due to pulmonary diseases. Polluted air first encounters the airways, which are a major human defense mechanism to reduce the risk of this aggressor. Air pollution consists of a mixture of potentially harmful compounds such as particulate matter, ozone, carbon monoxide, volatile organic compounds, and heavy metals, each having its own effects on the human body. In the last decades, a lot of research investigating the underlying risks and effects of air pollution and/or its specific compounds on the airways, has been performed, involving both in vivo and in vitro experiments. The goal of this review is to give an overview of the recent data on the effects of air pollution on healthy and diseased airways or models of airway disease, such as asthma or chronic obstructive pulmonary disease. Therefore, we focused on studies involving pollution and airway symptoms and/or damage both in mice and humans.
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11
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Phelan DE, Shigemura M, Aldhafiri S, Mota C, Hall TJ, Sznajder JI, Murphy EP, Crean D, Cummins EP. Transcriptional Profiling of Monocytes Deficient in Nuclear Orphan Receptors NR4A2 and NR4A3 Reveals Distinct Signalling Roles Related to Antigen Presentation and Viral Response. Front Immunol 2021; 12:676644. [PMID: 34248958 PMCID: PMC8267906 DOI: 10.3389/fimmu.2021.676644] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 06/07/2021] [Indexed: 11/22/2022] Open
Abstract
The nuclear receptor sub-family 4 group A (NR4A) family are early response genes that encode proteins that are activated in several tissues/cells in response to a variety of stressors. The NR4A family comprises NR4A1, NR4A2 and NR4A3 of which NR4A2 and NR4A3 are under researched and less understood, particularly in the context of immune cells. NR4A expression is associated with multiple diseases e.g. arthritis and atherosclerosis and the development of NR4A-targetting molecules as therapeutics is a current focus in this research field. Here, we use a combination of RNA-sequencing coupled with strategic bioinformatic analysis to investigate the down-stream effects of NR4A2 and NR4A3 in monocytes and dissect their common and distinct signalling roles. Our data reveals that NR4A2 and NR4A3 depletion has a robust and broad-reaching effect on transcription in both the unstimulated state and in the presence of LPS. Interestingly, many of the genes affected were present in both the unstimulated and stimulated states revealing a previously unappreciated role for the NR4As in unstimulated cells. Strategic clustering and bioinformatic analysis identified both distinct and common transcriptional roles for NR4A2 and NR4A3 in monocytes. NR4A2 notably was linked by both bioinformatic clustering analysis and transcription factor interactome analysis to pathways associated with antigen presentation and regulation of MHC genes. NR4A3 in contrast was more closely linked to pathways associated with viral response. Functional studies further support our data analysis pointing towards preferential/selective roles for NR4A2 in the regulation of antigen processing with common roles for NR4A2 and NR4A3 evident with respect to cell migration. Taken together this study provides novel mechanistic insights into the role of the enigmatic nuclear receptors NR4A2 and NR4A3 in monocytes.
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Affiliation(s)
- David E Phelan
- School of Medicine, University College Dublin, Dublin, Ireland.,Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Masahiko Shigemura
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Sarah Aldhafiri
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland.,Animal Genomics Laboratory, School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - Catarina Mota
- School of Medicine, University College Dublin, Dublin, Ireland.,Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Thomas J Hall
- School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - Jacob I Sznajder
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Evelyn P Murphy
- School of Medicine, University of Limerick, Limerick, Ireland
| | - Daniel Crean
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland.,Animal Genomics Laboratory, School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - Eoin P Cummins
- School of Medicine, University College Dublin, Dublin, Ireland.,Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
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12
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Phelan DE, Mota C, Lai C, Kierans SJ, Cummins EP. Carbon dioxide-dependent signal transduction in mammalian systems. Interface Focus 2021; 11:20200033. [PMID: 33633832 PMCID: PMC7898142 DOI: 10.1098/rsfs.2020.0033] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2020] [Indexed: 12/15/2022] Open
Abstract
Carbon dioxide (CO2) is a fundamental physiological gas known to profoundly influence the behaviour and health of millions of species within the plant and animal kingdoms in particular. A recent Royal Society meeting on the topic of 'Carbon dioxide detection in biological systems' was extremely revealing in terms of the multitude of roles that different levels of CO2 play in influencing plants and animals alike. While outstanding research has been performed by leading researchers in the area of plant biology, neuronal sensing, cell signalling, gas transport, inflammation, lung function and clinical medicine, there is still much to be learned about CO2-dependent sensing and signalling. Notably, while several key signal transduction pathways and nodes of activity have been identified in plants and animals respectively, the precise wiring and sensitivity of these pathways to CO2 remains to be fully elucidated. In this article, we will give an overview of the literature relating to CO2-dependent signal transduction in mammalian systems. We will highlight the main signal transduction hubs through which CO2-dependent signalling is elicited with a view to better understanding the complex physiological response to CO2 in mammalian systems. The main topics of discussion in this article relate to how changes in CO2 influence cellular function through modulation of signal transduction networks influenced by pH, mitochondrial function, adenylate cyclase, calcium, transcriptional regulators, the adenosine monophosphate-activated protein kinase pathway and direct CO2-dependent protein modifications. While each of these topics will be discussed independently, there is evidence of significant cross-talk between these signal transduction pathways as they respond to changes in CO2. In considering these core hubs of CO2-dependent signal transduction, we hope to delineate common elements and identify areas in which future research could be best directed.
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Affiliation(s)
- D. E. Phelan
- School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - C. Mota
- School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - C. Lai
- School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - S. J. Kierans
- School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - E. P. Cummins
- School of Medicine, University College Dublin, Belfield, Dublin 4, Ireland
- Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
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Masterson C, Horie S, McCarthy SD, Gonzalez H, Byrnes D, Brady J, Fandiño J, Laffey JG, O'Toole D. Hypercapnia in the critically ill: insights from the bench to the bedside. Interface Focus 2021; 11:20200032. [PMID: 33628425 PMCID: PMC7898152 DOI: 10.1098/rsfs.2020.0032] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2020] [Indexed: 01/16/2023] Open
Abstract
Carbon dioxide (CO2) has long been considered, at best, a waste by-product of metabolism, and at worst, a toxic molecule with serious health consequences if physiological concentration is dysregulated. However, clinical observations have revealed that 'permissive' hypercapnia, the deliberate allowance of respiratory produced CO2 to remain in the patient, can have anti-inflammatory effects that may be beneficial in certain circumstances. In parallel, studies at the cell level have demonstrated the profound effect of CO2 on multiple diverse signalling pathways, be it the effect from CO2 itself specifically or from the associated acidosis it generates. At the whole organism level, it now appears likely that there are many biological sensing systems designed to respond to CO2 concentration and tailor respiratory and other responses to atmospheric or local levels. Animal models have been widely employed to study the changes in CO2 levels in various disease states and also to what extent permissive or even directly delivered CO2 can affect patient outcome. These findings have been advanced to the bedside at the same time that further clinical observations have been elucidated at the cell and animal level. Here we present a synopsis of the current understanding of how CO2 affects mammalian biological systems, with a particular emphasis on inflammatory pathways and diseases such as lung specific or systemic sepsis. We also explore some future directions and possibilities, such as direct control of blood CO2 levels, that could lead to improved clinical care in the future.
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Abstract
Carbon dioxide (CO2), a primary product of oxidative metabolism, can be sensed by eukaryotic cells eliciting unique responses via specific signalling pathways. Severe lung diseases such as chronic obstructive pulmonary disease are associated with hypoventilation that can lead to the elevation of CO2 levels in lung tissues and the bloodstream (hypercapnia). However, the pathophysiological effects of hypercapnia on the lungs and specific lung cells are incompletely understood. We have recently reported using combined unbiased molecular approaches with studies in mice and cell culture systems on the mechanisms by which hypercapnia alters airway smooth muscle contractility. In this review, we provide a pathophysiological and mechanistic perspective on the effects of hypercapnia on the lung airways and discuss the recent understanding of high CO2 modulation of the airway contractility.
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Affiliation(s)
- Masahiko Shigemura
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, IL, USA
| | - Jacob I Sznajder
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, IL, USA
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15
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Casalino-Matsuda SM, Berdnikovs S, Wang N, Nair A, Gates KL, Beitel GJ, Sporn PHS. Hypercapnia selectively modulates LPS-induced changes in innate immune and DNA replication-related gene transcription in the macrophage. Interface Focus 2021; 11:20200039. [PMID: 33633835 DOI: 10.1098/rsfs.2020.0039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2020] [Indexed: 12/14/2022] Open
Abstract
Hypercapnia, the elevation of CO2 in blood and tissues, commonly occurs in severe acute and chronic respiratory diseases and is associated with increased risk of death. Recent studies have shown that hypercapnia inhibits expression of select innate immune genes and suppresses host defence against bacterial and viral pneumonia in mice. In the current study, we evaluated the effect of culture under conditions of hypercapnia (20% CO2) versus normocapnia (5% CO2), both with normoxia, on global gene transcription in human THP-1 and mouse RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS). We found that hypercapnia selectively downregulated transcription of LPS-induced genes associated with innate immunity, antiviral response, type I interferon signalling, cytokine signalling and other inflammatory pathways in both human and mouse macrophages. Simultaneously, hypercapnia increased expression of LPS-downregulated genes associated with mitosis, DNA replication and DNA repair. These CO2-induced changes in macrophage gene expression help explain hypercapnic suppression of antibacterial and antiviral host defence in mice and reveal a mechanism that may underlie, at least in part, the high mortality of patients with severe lung disease and hypercapnia.
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Affiliation(s)
- S Marina Casalino-Matsuda
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Sergejs Berdnikovs
- Division of Allergy-Immunology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Naizhen Wang
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Aisha Nair
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Khalilah L Gates
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Greg J Beitel
- Department of Molecular Biosciences, Weinberg College of Arts and Sciences, Northwestern University, Evanston, IL 60208, USA
| | - Peter H S Sporn
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.,Medical Service, Jesse Brown Veterans Affairs Medical Center, Chicago, IL 60612, USA
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16
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Ceco E, Celli D, Weinberg S, Shigemura M, Welch LC, Volpe L, Chandel NS, Bharat A, Lecuona E, Sznajder JI. Elevated CO 2 Levels Delay Skeletal Muscle Repair by Increasing Fatty Acid Oxidation. Front Physiol 2021; 11:630910. [PMID: 33551852 PMCID: PMC7859333 DOI: 10.3389/fphys.2020.630910] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 12/24/2020] [Indexed: 11/16/2022] Open
Abstract
Muscle dysfunction often occurs in patients with chronic obstructive pulmonary diseases (COPD) and affects ventilatory and non-ventilatory skeletal muscles. We have previously reported that hypercapnia (elevated CO2 levels) causes muscle atrophy through the activation of the AMPKα2-FoxO3a-MuRF1 pathway. In the present study, we investigated the effect of normoxic hypercapnia on skeletal muscle regeneration. We found that mouse C2C12 myoblasts exposed to elevated CO2 levels had decreased fusion index compared to myoblasts exposed to normal CO2. Metabolic analyses of C2C12 myoblasts exposed to high CO2 showed increased oxidative phosphorylation due to increased fatty acid oxidation. We utilized the cardiotoxin-induced muscle injury model in mice exposed to normoxia and 10% CO2 for 21 days and observed that muscle regeneration was delayed. High CO2-delayed differentiation in both mouse C2C12 myoblasts and skeletal muscle after injury and was restored to control levels when cells or mice were treated with a carnitine palmitoyltransfearse-1 (CPT1) inhibitor. Taken together, our data suggest that hypercapnia leads to changes in the metabolic activity of skeletal muscle cells, which results in impaired muscle regeneration and recovery after injury.
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Affiliation(s)
- Ermelinda Ceco
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Diego Celli
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Samuel Weinberg
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Masahiko Shigemura
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Lynn C Welch
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Lena Volpe
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Navdeep S Chandel
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Ankit Bharat
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States.,Division of Thoracic Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Emilia Lecuona
- Division of Thoracic Surgery, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Jacob I Sznajder
- Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
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17
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Shigemura M, Welch LC, Sznajder JI. Hypercapnia Regulates Gene Expression and Tissue Function. Front Physiol 2020; 11:598122. [PMID: 33329047 PMCID: PMC7715027 DOI: 10.3389/fphys.2020.598122] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 10/26/2020] [Indexed: 01/20/2023] Open
Abstract
Carbon dioxide (CO2) is produced in eukaryotic cells primarily during aerobic respiration, resulting in higher CO2 levels in mammalian tissues than those in the atmosphere. CO2 like other gaseous molecules such as oxygen and nitric oxide, is sensed by cells and contributes to cellular and organismal physiology. In humans, elevation of CO2 levels in tissues and the bloodstream (hypercapnia) occurs during impaired alveolar gas exchange in patients with severe acute and chronic lung diseases. Advances in understanding of the biology of high CO2 effects reveal that the changes in CO2 levels are sensed in cells resulting in specific tissue responses. There is accumulating evidence on the transcriptional response to elevated CO2 levels that alters gene expression and activates signaling pathways with consequences for cellular and tissue functions. The nature of hypercapnia-responsive transcriptional regulation is an emerging area of research, as the responses to hypercapnia in different cell types, tissues, and species are not fully understood. Here, we review the current understanding of hypercapnia effects on gene transcription and consequent cellular and tissue functions.
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Affiliation(s)
- Masahiko Shigemura
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, IL, United States
| | - Lynn C Welch
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, IL, United States
| | - Jacob I Sznajder
- Division of Pulmonary and Critical Care Medicine, Northwestern University, Chicago, IL, United States
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18
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Hypercapnia: An Aggravating Factor in Asthma. J Clin Med 2020; 9:jcm9103207. [PMID: 33027886 PMCID: PMC7599850 DOI: 10.3390/jcm9103207] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 10/01/2020] [Accepted: 10/02/2020] [Indexed: 02/06/2023] Open
Abstract
Asthma is a common chronic respiratory disorder with relatively good outcomes in the majority of patients with appropriate maintenance therapy. However, in a small minority, patients can experience severe asthma with respiratory failure and hypercapnia, necessitating intensive care unit admission. Hypercapnia occurs due to alveolar hypoventilation and insufficient removal of carbon dioxide (CO2) from the blood. Although mild hypercapnia is generally well tolerated in patients with asthma, there is accumulating evidence that elevated levels of CO2 can act as a gaso-signaling molecule, triggering deleterious effects in various organs such as the lung, skeletal muscles and the innate immune system. Here, we review recent advances on pathophysiological response to hypercapnia and discuss potential detrimental effects of hypercapnia in patients with asthma.
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Correlation of Arterial CO 2 and Respiratory Impedance Values among Subjects with COPD. J Clin Med 2020; 9:jcm9092819. [PMID: 32878165 PMCID: PMC7564107 DOI: 10.3390/jcm9092819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 12/15/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) is a respiratory illness characterized by airflow limitation and chronic respiratory symptoms with a global prevalence estimated to be more than 10% in 2010 and still on the rise. Furthermore, hypercapnic subject COPD leads to an increased risk of mortality, morbidity, and poor QoL (quality of life) than normocapnic subjects. Series of studies showed the usefulness of the forced oscillation technique (FOT) to measure small airway closure. Traditional findings suggested that hypercapnia may not be the main treating targets, but recent findings suggested that blood stream CO2 may lead to a worse outcome. This study aimed to seek the relationship between CO2 and small airway closure by using FOT. Subjects with COPD (n = 124; hypercapnia 22 and normocapnia 102) were analyzed for all pulmonary function values, FOT values, and arterial blood gas analysis. Student’s t-test, Spearman rank correlation, and multi linear regression analysis were used to analyze the data. COPD subjects with hypercapnia showed a significant increase in R5, R20, Fres, and ALX values, and a greater decrease in X5 value than normocapnic patients. Also, multiple linear regression analysis showed R5 was associated with hypercapnia. Hypercapnia may account for airway closure among subjects with COPD and this result suggests treating hypercapnia may lead to better outcomes for such a subject group.
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