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Immanuel CN, Teng B, Dong BE, Gordon EM, Luellen C, Lopez B, Harding J, Cormier SA, Fitzpatrick EA, Schwingshackl A, Waters CM. Two-pore potassium channel TREK-1 (K2P2.1) regulates NLRP3 inflammasome activity in macrophages. Am J Physiol Lung Cell Mol Physiol 2024; 326:L367-L376. [PMID: 38252657 PMCID: PMC11281793 DOI: 10.1152/ajplung.00313.2023] [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: 10/05/2023] [Revised: 01/08/2024] [Accepted: 01/17/2024] [Indexed: 01/24/2024] Open
Abstract
Because of the importance of potassium efflux in inflammasome activation, we investigated the role of the two-pore potassium (K2P) channel TREK-1 in macrophage inflammasome activity. Using primary alveolar macrophages (AMs) and bone marrow-derived macrophages (BMDMs) from wild-type (wt) and TREK-1-/- mice, we measured responses to inflammasome priming [using lipopolysaccharide (LPS)] and activation (LPS + ATP). We measured IL-1β, caspase-1, and NLRP3 via ELISA and Western blot. A membrane-permeable potassium indicator was used to measure potassium efflux during ATP exposure, and a fluorescence-based assay was used to assess changes in membrane potential. Inflammasome activation induced by LPS + ATP increased IL-1β secretion in wt AMs, whereas activation was significantly reduced in TREK-1-/- AMs. Priming of BMDMs using LPS was not affected by either genetic deficiency or pharmacological inhibition of TREK-1 with Spadin. Cleavage of caspase-1 following LPS + ATP treatment was significantly reduced in TREK-1-/- BMDMs. The intracellular potassium concentration in LPS-primed wt BMDMs was significantly lower compared with TREK-1-/- BMDMs or wt BMDMs treated with Spadin. Conversely, activation of TREK-1 with BL1249 caused a decrease in intracellular potassium in wt BMDMs. Treatment of LPS-primed BMDMs with ATP caused a rapid reduction in intracellular potassium levels, with the largest change observed in TREK-1-/- BMDMs. Intracellular K+ changes were associated with changes in the plasma membrane potential (Em), as evidenced by a more depolarized Em in TREK-1-/- BMDMs compared with wt, and Em hyperpolarization upon TREK-1 channel opening with BL1249. These results suggest that TREK-1 is an important regulator of NLRP3 inflammasome activation in macrophages.NEW & NOTEWORTHY Because of the importance of potassium efflux in inflammasome activation, we investigated the role of the two-pore potassium (K2P) channel TREK-1 in macrophage inflammasome activity. Using primary alveolar macrophages and bone marrow-derived macrophages from wild-type and TREK-1-/- mice, we measured responses to inflammasome priming (using LPS) and activation (LPS + ATP). Our results suggest that TREK-1 is an important regulator of NLRP3 inflammasome activation in macrophages.
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Grants
- HL131526 HHS | NIH | National Heart, Lung, and Blood Institute (NHLBI)
- Le Bonheur Children's Hospital
- 20TPA35490010 American Heart Association (AHA)
- R01 HL131526 NHLBI NIH HHS
- HL151419 HHS | NIH | National Heart, Lung, and Blood Institute (NHLBI)
- IA-678511 American Lung Association (ALA)
- R01 HL146821 NHLBI NIH HHS
- HL146821 HHS | NIH | National Heart, Lung, and Blood Institute (NHLBI)
- HL123540 HHS | NIH | National Heart, Lung, and Blood Institute (NHLBI)
- R01 HL151419 NHLBI NIH HHS
- R01 HL123540 NHLBI NIH HHS
- HHS | NIH | National Heart, Lung, and Blood Institute (NHBLI)
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Affiliation(s)
- Camille N Immanuel
- Division of Pediatric Critical Care, Department of Pediatrics, Le Bonheur Children's Hospital, University of Tennessee Health Science Center, Memphis, Tennessee, United States
- Department of Physiology, Saha Cardiovascular Research Center, University of Kentucky, Lexington, Kentucky, United States
| | - Bin Teng
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Brittany E Dong
- Department of Physiology, Saha Cardiovascular Research Center, University of Kentucky, Lexington, Kentucky, United States
| | - Elizabeth M Gordon
- Department of Physiology, Saha Cardiovascular Research Center, University of Kentucky, Lexington, Kentucky, United States
| | - Charlean Luellen
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Benjamin Lopez
- Department of Pediatrics, University of California, Los Angeles, California, United States
| | - Jeffrey Harding
- Department of Biological Sciences, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, United States
| | - Stephania A Cormier
- Department of Biological Sciences, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana, United States
| | - Elizabeth A Fitzpatrick
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Andreas Schwingshackl
- Department of Pediatrics, University of California, Los Angeles, California, United States
| | - Christopher M Waters
- Department of Physiology, Saha Cardiovascular Research Center, University of Kentucky, Lexington, Kentucky, United States
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Aubin Vega M, Girault A, Meunier É, Chebli J, Privé A, Robichaud A, Adam D, Brochiero E. Function of KvLQT1 potassium channels in a mouse model of bleomycin-induced acute lung injury. Front Physiol 2024; 15:1345488. [PMID: 38444763 PMCID: PMC10912346 DOI: 10.3389/fphys.2024.1345488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 01/30/2024] [Indexed: 03/07/2024] Open
Abstract
Acute respiratory distress syndrome (ARDS) is characterized by an exacerbated inflammatory response, severe damage to the alveolar-capillary barrier and a secondary infiltration of protein-rich fluid into the airspaces, ultimately leading to respiratory failure. Resolution of ARDS depends on the ability of the alveolar epithelium to reabsorb lung fluid through active transepithelial ion transport, to control the inflammatory response, and to restore a cohesive and functional epithelium through effective repair processes. Interestingly, several lines of evidence have demonstrated the important role of potassium (K+) channels in the regulation of epithelial repair processes. Furthermore, these channels have previously been shown to be involved in sodium/fluid absorption across alveolar epithelial cells, and we have recently demonstrated the contribution of KvLQT1 channels to the resolution of thiourea-induced pulmonary edema in vivo. The aim of our study was to investigate the role of the KCNQ1 pore-forming subunit of KvLQT1 channels in the outcome of ARDS parameters in a model of acute lung injury (ALI). We used a molecular approach with KvLQT1-KO mice challenged with bleomycin, a well-established ALI model that mimics the key features of the exudative phase of ARDS on day 7. Our data showed that KvLQT1 deletion exacerbated the negative outcome of bleomycin on lung function (resistance, elastance and compliance). An alteration in the profile of infiltrating immune cells was also observed in KvLQT1-KO mice while histological analysis showed less interstitial and/or alveolar inflammatory response induced by bleomycin in KvLQT1-KO mice. Finally, a reduced repair rate of KvLQT1-KO alveolar cells after injury was observed. This work highlights the complex contribution of KvLQT1 in the development and resolution of ARDS parameters in a model of ALI.
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Affiliation(s)
- Mélissa Aubin Vega
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
- Département de Médecine, Université de Montréal, Montréal, QC, Canada
| | - Alban Girault
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
- Département de Médecine, Université de Montréal, Montréal, QC, Canada
- Laboratoire de Physiologie Cellulaire et Moléculaire (LPCM UR UPJV 4667), Amiens, France
| | - Émilie Meunier
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
- Département de Médecine, Université de Montréal, Montréal, QC, Canada
| | - Jasmine Chebli
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
- Département de Médecine, Université de Montréal, Montréal, QC, Canada
| | - Anik Privé
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
| | | | - Damien Adam
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
- Département de Médecine, Université de Montréal, Montréal, QC, Canada
| | - Emmanuelle Brochiero
- Centre de recherche du Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal, QC, Canada
- Département de Médecine, Université de Montréal, Montréal, QC, Canada
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3
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Zhi Y, Wu X, Chen Y, Chen X, Chen X, Luo H, Yi X, Lin X, Ma L, Chen Y, Cao Y, Li F, Zhou P. A novel TWIK2 channel inhibitor binds at the bottom of the selectivity filter and protects against LPS-induced experimental endotoxemia in vivo. Biochem Pharmacol 2023; 218:115894. [PMID: 37898389 DOI: 10.1016/j.bcp.2023.115894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Revised: 10/24/2023] [Accepted: 10/25/2023] [Indexed: 10/30/2023]
Abstract
TWIK2 channel plays a critical role in NLRP3 inflammasome activation and mice deficient in TWIK2 channel are protected from sepsis and inflammatory lung injury. However, inhibitors of TWIK2 channel are currently in an early stage of development, and the molecular determinants underlying the chemical modulation of TWIK2 channel remain unexplored. In this study, we identified NPBA and the synthesized derivative NPBA-4 potently and selectively inhibited TWIK2 channel by using whole-cell patch clamp techniques. Furthermore, the mutation of the last residues of the selectivity filter in both P1 and P2 (i.e., T106A, T214A) of TWIK2 channel substantially abolished the effect of NPBA on TWIK2 channel. Our data suggest that NPBA blocked TWIK2 channel through binding at the bottom of the selectivity filter, which was also supported by molecular docking prediction. Moreover, we found that NPBA significantly suppressed NLRP3 inflammasome activation in macrophages and alleviated LPS-induced endotoxemia and organ injury in vivo. Notably, the protective effects of NPBA against LPS-induced endotoxemia were abolished in Kcnk6-/- mice. In summary, our study has uncovered a series of novel inhibitors of TWIK2 channel and revealed their distinct molecular determinants interacting TWIK2 channel. These findings provide new insights into the mechanisms of pharmacological action on TWIK2 channel and opportunities for the development of selective TWIK2 channel modulators to treat related inflammatory diseases.
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Affiliation(s)
- Yuanxing Zhi
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China; Department of Anesthesiology, Zhujiang Hospital of Southern Medical University, Guangzhou 510282, China
| | - Xiaoyan Wu
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Yanshan Chen
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Xingyuan Chen
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Xiangyu Chen
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Hui Luo
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Xin Yi
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Xiuling Lin
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Liang Ma
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Yao Chen
- Department of Anesthesiology, Zhujiang Hospital of Southern Medical University, Guangzhou 510282, China
| | - Ying Cao
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China
| | - Fengxian Li
- Department of Anesthesiology, Zhujiang Hospital of Southern Medical University, Guangzhou 510282, China
| | - Pingzheng Zhou
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, China; Department of Anesthesiology, Zhujiang Hospital of Southern Medical University, Guangzhou 510282, China.
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4
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Man Q, Gao Z, Chen K. Functional Potassium Channels in Macrophages. J Membr Biol 2023; 256:175-187. [PMID: 36622407 DOI: 10.1007/s00232-022-00276-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 12/30/2022] [Indexed: 01/10/2023]
Abstract
Macrophages are the predominant component of innate immunity, which is an important protective barrier of our body. Macrophages are present in all organs and tissues of the body, their main functions include immune surveillance, bacterial killing, tissue remodeling and repair, and clearance of cell debris. In addition, macrophages can present antigens to T cells and facilitate inflammatory response by releasing cytokines. Macrophages are of high concern due to their crucial roles in multiple physiological processes. In recent years, new advances are emerging after great efforts have been made to explore the mechanisms of macrophage activation. Ion channel is a class of multimeric transmembrane protein that allows specific ions to go through cell membrane. The flow of ions through ion channel between inside and outside of cell membrane is required for maintaining cell morphology and intracellular signal transduction. Expressions of various ion channels in macrophages have been detected. The roles of ion channels in macrophage activation are gradually caught attention. K+ channels are the most studied channels in immune system. However, very few of published papers reviewed the studies of K+ channels on macrophages. Here, we will review the four types of K+ channels that are expressed in macrophages: voltage-gated K+ channel, calcium-activated K+ channel, inwardly rectifying K+ channel and two-pore domain K+ channel.
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Affiliation(s)
- Qiaoyan Man
- Department of Pharmacology, Ningbo University School of Medicine, A506, Wang Changlai Building818 Fenghua Rd, Ningbo, China
| | - Zhe Gao
- Ningbo Institute of Medical Sciences, 42 Yangshan Rd, Ningbo, China.
| | - Kuihao Chen
- Department of Pharmacology, Ningbo University School of Medicine, A506, Wang Changlai Building818 Fenghua Rd, Ningbo, China.
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5
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Jia Q, Yang Y, Chen X, Yao S, Hu Z. Emerging roles of mechanosensitive ion channels in acute lung injury/acute respiratory distress syndrome. Respir Res 2022; 23:366. [PMID: 36539808 PMCID: PMC9764320 DOI: 10.1186/s12931-022-02303-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a devastating respiratory disorder with high rates of mortality and morbidity, but the detailed underlying mechanisms of ALI/ARDS remain largely unknown. Mechanosensitive ion channels (MSCs), including epithelial sodium channel (ENaC), Piezo channels, transient receptor potential channels (TRPs), and two-pore domain potassium ion (K2P) channels, are highly expressed in lung tissues, and the activity of these MSCs can be modulated by mechanical forces (e.g., mechanical ventilation) and other stimuli (e.g., LPS, hyperoxia). Dysfunction of MSCs has been found in various types of ALI/ARDS, and MSCs play a key role in regulating alveolar fluid clearance, alveolar epithelial/endothelial barrier function, the inflammatory response and surfactant secretion in ALI/ARDS lungs. Targeting MSCs exerts therapeutic effects in the treatment of ALI/ARDS. In this review, we summarize the structure and functions of several well-recognized MSCs, the role of MSCs in the pathogenesis of ALI/ARDS and recent advances in the pharmacological and molecular modulation of MSCs in the treatment of ALI/ARDS. According to the current literature, targeting MSCs might be a very promising therapeutic approach against ALI/ARDS.
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Affiliation(s)
- Qi Jia
- grid.33199.310000 0004 0368 7223Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yiyi Yang
- grid.33199.310000 0004 0368 7223Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiangdong Chen
- grid.33199.310000 0004 0368 7223Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shanglong Yao
- grid.33199.310000 0004 0368 7223Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhiqiang Hu
- grid.33199.310000 0004 0368 7223Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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6
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Zyrianova T, Lopez B, Liao A, Gu C, Wong L, Ottolia M, Olcese R, Schwingshackl A. BK Channels Regulate LPS-induced CCL-2 Release from Human Pulmonary Endothelial Cells. Am J Respir Cell Mol Biol 2021; 64:224-234. [PMID: 33217242 PMCID: PMC7874395 DOI: 10.1165/rcmb.2020-0228oc] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 11/05/2020] [Indexed: 11/24/2022] Open
Abstract
We recently established a role for the stretch-activated two-pore-domain K+ (K2P) channel TREK-1 (K2P2.1) in inflammatory cytokine secretion using models of hyperoxia-, mechanical stretch-, and TNF-α-induced acute lung injury. We have now discovered the expression of large conductance, Ca2+-activated K+ (BK) channels in human pulmonary microvascular endothelial cells and primary human alveolar epithelial cells using semiquantitative real-time PCR, IP and Western blot, and investigated their role in inflammatory cytokine secretion using an LPS-induced acute lung injury model. As expected, LPS induced IL-6 and CCL-2 secretion from pulmonary endothelial and epithelial cells. BK activation with NS1619 decreased LPS-induced CCL-2 but not IL-6 secretion from endothelial cells and had no effect on epithelial cells, although fluorometric assays revealed that BK activation hyperpolarized the plasma membrane potential (Em) of both cell types. Interestingly, BK inhibition (Paxilline) did not alter cytokine secretion or the Em in either cell type. Furthermore, LPS treatment by itself did not affect the Em or intracellular Ca2+ concentrations. Therefore, we propose BK channel activation as a novel targeted approach to counteract LPS-induced CCL-2 secretion from endothelial cells. This protective effect appears to occur via Em hyperpolarization but independent of intracellular Ca2+ concentrations.
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Affiliation(s)
| | | | | | | | | | - Michela Ottolia
- Department of Anesthesiology and Perioperative Medicine, and
| | - Riccardo Olcese
- Department of Anesthesiology and Perioperative Medicine, and
- Department of Physiology, University of California Los Angeles, Los Angeles, California
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7
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K 2P2.1 (TREK-1) potassium channel activation protects against hyperoxia-induced lung injury. Sci Rep 2020; 10:22011. [PMID: 33319831 PMCID: PMC7738539 DOI: 10.1038/s41598-020-78886-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 12/01/2020] [Indexed: 12/20/2022] Open
Abstract
No targeted therapies exist to counteract Hyperoxia (HO)-induced Acute Lung Injury (HALI). We previously found that HO downregulates alveolar K2P2.1 (TREK-1) K+ channels, which results in worsening lung injury. This decrease in TREK-1 levels leaves a subset of channels amendable to pharmacological intervention. Therefore, we hypothesized that TREK-1 activation protects against HALI. We treated HO-exposed mice and primary alveolar epithelial cells (AECs) with the novel TREK-1 activators ML335 and BL1249, and quantified physiological, histological, and biochemical lung injury markers. We determined the effects of these drugs on epithelial TREK-1 currents, plasma membrane potential (Em), and intracellular Ca2+ (iCa) concentrations using fluorometric assays, and blocked voltage-gated Ca2+ channels (CaV) as a downstream mechanism of cytokine secretion. Once-daily, intra-tracheal injections of HO-exposed mice with ML335 or BL1249 improved lung compliance, histological lung injury scores, broncho-alveolar lavage protein levels and cell counts, and IL-6 and IP-10 concentrations. TREK-1 activation also decreased IL-6, IP-10, and CCL-2 secretion from primary AECs. Mechanistically, ML335 and BL1249 induced TREK-1 currents in AECs, counteracted HO-induced cell depolarization, and lowered iCa2+ concentrations. In addition, CCL-2 secretion was decreased after L-type CaV inhibition. Therefore, Em stabilization with TREK-1 activators may represent a novel approach to counteract HALI.
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8
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Kamatham S, Waters CM, Schwingshackl A, Mancarella S. TREK-1 protects the heart against ischemia-reperfusion-induced injury and from adverse remodeling after myocardial infarction. Pflugers Arch 2019; 471:1263-1272. [PMID: 31511966 DOI: 10.1007/s00424-019-02306-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 08/12/2019] [Accepted: 08/22/2019] [Indexed: 11/28/2022]
Abstract
The TWIK-related K+ channel (TREK-1) is a two-pore-domain potassium channel that produces background leaky potassium currents. TREK-1 has a protective role against ischemia-induced neuronal damage. TREK-1 is also expressed in the heart, but its role in myocardial ischemia-reperfusion (IR)-induced injury has not been examined. In the current study, we used a TREK-1 knockout (KO) mouse model to show that TREK-1 has a critical role in the cardiac I/R-induced injury and during remodeling after myocardial infarction (MI). At baseline, TREK-1 KO mice had similar blood pressure and heart rate as the wild-type (WT) mice. However, the lack of TREK-1 was associated with increased susceptibility to ischemic injury and compromised functional recovery following ex vivo I/R-induced injury. TREK-1 deficiency increased infarct size following permanent coronary artery ligation, resulting in greater systolic dysfunction than the WT counterpart. Electrocardiographic (ECG) analysis revealed QT interval prolongation in TREK-1 KO mice, but normal heart rate (HR). Acutely isolated TREK-1 KO cardiomyocytes exhibited prolonged Ca2+ transient duration associated with action potential duration (APD) prolongation. Our data suggest that TREK-1 has a protective effect against I/R-induced injury and influences the post-MI remodeling processes by regulating membrane potential and maintaining intracellular Ca2+ homeostasis. These data suggest that TREK-1 activation could be an effective strategy to provide cardioprotection against ischemia-induced damage.
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Affiliation(s)
- Samuel Kamatham
- Department of Physiology, University of Tennessee Health Sciences Center, 71 S. Manassas Street, Memphis, TN, 38163, USA
| | - Christopher M Waters
- Department of Physiology, Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY, USA
| | - Andreas Schwingshackl
- Department of Pediatrics, University of California Los Angeles, Los Angeles, CA, USA
| | - Salvatore Mancarella
- Department of Physiology, University of Tennessee Health Sciences Center, 71 S. Manassas Street, Memphis, TN, 38163, USA.
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9
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Zhang H, Liu Y, Li H, Li J, Luo Y, Yan X. Novel insights into the role of LRRC8A in ameliorating alveolar fluid clearance in LPS induced acute lung injury. Eur J Pharmacol 2019; 861:172613. [PMID: 31421089 DOI: 10.1016/j.ejphar.2019.172613] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 08/10/2019] [Accepted: 08/14/2019] [Indexed: 01/08/2023]
Abstract
Leucine-rich repeat-containing 8A (LRRC8A) protein was recently identified as an essential component of volume-regulated anion channel which plays a central role in maintaining cell volume. The aim of this study was to elucidate the role of LRRC8A in alveolar fluid clearance (AFC) and the effect of inflammatory cytokines on LRRC8A and the underlying mechanism. Lipopolysaccharide (LPS) was used to generate a rat acute lung injury model. The results showed that the concentrations of IL-1β, TNF-α and IL-6 in bronchoalveolar lavage fluid increased significantly, but the expression of LRRC8A in the lung tissue decreased dramatically in the acute lung injury group followed by a decline in the AFC rate. Additionally, LRRC8A knockdown reduced AFC in normal rats. However, specific overexpression of LRRC8A in the lung could increase AFC. Furthermore, we observed the effects of LPS, IL-1β, TNF-α and IL-6 on the LRRC8A current in alveolar type II (ATII) cells, and IL-1β showed the greatest inhibition among them, which was involved in phospho-p38 activation. Overall, LRRC8A plays an essential role in the progression of AFC in LPS-induced acute lung injury, and chronic treatment with IL-1β or TNF-α could inhibit the function of LRRC8A in ATII cells by targeting phospho-p38. All of the findings suggested that LRRC8A could be a new partner in AFC and a potential target for the treatment of acute lung injury.
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Affiliation(s)
- Huiran Zhang
- Department of Respiratory and Critical Care Medicine, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Yani Liu
- Department of pharmacology, School of pharmacy, Qingdao University, Qingdao, Shandong, China
| | - Honglin Li
- Department of Respiratory and Critical Care Medicine, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Jingwen Li
- Department of Respiratory and Critical Care Medicine, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China; Department of Central Laboratory, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Yuan Luo
- Department of Respiratory and Critical Care Medicine, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Xixin Yan
- Department of Respiratory and Critical Care Medicine, The Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China.
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10
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Canella R, Martini M, Cavicchio C, Cervellati F, Benedusi M, Valacchi G. Involvement of the TREK-1 channel in human alveolar cell membrane potential and its regulation by inhibitors of the chloride current. J Cell Physiol 2019; 234:17704-17713. [PMID: 30805940 DOI: 10.1002/jcp.28396] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 01/03/2019] [Accepted: 01/10/2019] [Indexed: 12/14/2022]
Abstract
K+ channels of the alveolar epithelium control the driving force acting on the ionic and solvent flow through the cell membrane contributing to the maintenance of cell volume and the constitution of epithelial lining fluid. In the present work, we analyze the effect of the Cl- channel inhibitors: (4-[(2-butyl-6,7-dichloro-2-cyclopentyl-2,3-dihydro-1-oxo-inden-5-yl)oxy] butanoic acid (DCPIB) and 9-anthracenecarboxylic acid (9-AC) on the total current in a type II pneumocytes (A549 cell line) model by patch clamp, immunocytochemical, and gene knockdown techniques. We noted that DCPIB and 9-AC promote the activation of K conductance. In fact, they significantly increase the intensity of the current and shift its reversal potential to values more negative than the control. By silencing outward rectifier channel in its anoctamin 6 portion, we excluded a direct involvement of Cl- ions in modulation of IK and, by means of functional tests with its specific inhibitor spadin, we identified the TREK-1 channel as the presumable target of both drugs. As the activity of TREK-1 has a key role for the correct functioning of the alveolar epithelium, the identification of DCPIB and 9-AC molecules as its activators suggests their possible use to build new pharmacological tools for the modulation of this channel.
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Affiliation(s)
- Rita Canella
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Marta Martini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Carlotta Cavicchio
- Animal Science Department, Plants for Human Health Institute, NC State University, Kannapolis, North Carolina
| | - Franco Cervellati
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Mascia Benedusi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Giuseppe Valacchi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.,Animal Science Department, Plants for Human Health Institute, NC State University, Kannapolis, North Carolina
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11
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Jin Y, Liu Y, Nelin LD. Deficiency of cationic amino acid transporter-2 protects mice from hyperoxia-induced lung injury. Am J Physiol Lung Cell Mol Physiol 2019; 316:L598-L607. [PMID: 30628488 DOI: 10.1152/ajplung.00223.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The pathology of acute lung injury (ALI) involves inducible nitric oxide (NO) synthase (iNOS)-derived NO-induced apoptosis of pulmonary endothelial cells. In vitro, iNOS-derived NO production has been shown to depend on the uptake of l-arginine by the cationic amino acid transporters (CAT). To test the hypothesis that mice deficient in CAT-2 ( slc7a2-/- on a C57BL/6 background) would be protected from hyperoxia-induced ALI, mice ( slc7a2-/- or wild-type) were placed in >95% oxygen (hyperoxia) or 21% oxygen (control) for 60 h. In wild-type mice exposed to hyperoxia, the exhaled nitric oxide (exNO) was twofold greater than in wild-type mice exposed to normoxia ( P < 0.005), whereas in slc7a2-/- mice there was no significant difference between exNO in animals exposed to hyperoxia or normoxia ( P = 0.95). Hyperoxia-exposed wild-type mice had greater ( P < 0.05) lung resistance and a lower ( P < 0.05) lung compliance than did hyperoxia-exposed slc7a2-/- mice. The lung wet-to-dry weight ratio was greater ( P < 0.005) in the hyperoxia-exposed wild-type mice than in hyperoxia-exposed slc7a2-/- mice. Neutrophil infiltration was lower ( P < 0.05) in the hyperoxia-exposed slc7a2-/- mice than in the hyperoxia-exposed wild-type mice as measured by myeloperoxidase activity. The protein concentration in bronchoalveolar lavage fluid was lower ( P < 0.001) in the hyperoxia-exposed slc7a2-/- mice than in similarly exposed wild-type mice. The percent of TUNEL-positive cells in the lung following hyperoxia exposure was significantly lower ( P < 0.001) in the slc7a2-/- mice than in the wild-type mice. These results are consistent with our hypothesis that lack of CAT-2 protects mice from acute lung injury.
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Affiliation(s)
- Yi Jin
- Pulmonary Hypertension Group, Center for Perinatal Research, Research Institute at Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University , Columbus, Ohio
| | - Yusen Liu
- Pulmonary Hypertension Group, Center for Perinatal Research, Research Institute at Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University , Columbus, Ohio
| | - Leif D Nelin
- Pulmonary Hypertension Group, Center for Perinatal Research, Research Institute at Nationwide Children's Hospital, and Department of Pediatrics, The Ohio State University , Columbus, Ohio
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12
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Blatteau JE, Gaillard S, De Maistre S, Richard S, Louges P, Gempp E, Druelles A, Lehot H, Morin J, Castagna O, Abraini JH, Risso JJ, Vallée N. Reduction in the Level of Plasma Mitochondrial DNA in Human Diving, Followed by an Increase in the Event of an Accident. Front Physiol 2018; 9:1695. [PMID: 30555340 PMCID: PMC6282000 DOI: 10.3389/fphys.2018.01695] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 11/09/2018] [Indexed: 01/02/2023] Open
Abstract
Circulating mitochondrial DNA (mtDNA) is receiving increasing attention as a danger-associated molecular pattern in conditions such as autoimmunity or trauma. In the context of decompression sickness (DCS), the course of which is sometimes erratic, we hypothesize that mtDNA plays a not insignificant role particularly in neurological type accidents. This study is based on the comparison of circulating mtDNA levels in humans presenting with various types of diving accidents, and punctured upon their admission at the hyperbaric facility. One hundred and fourteen volunteers took part in the study. According to the clinical criteria there were 12 Cerebro DCS, 57 Medullary DCS, 15 Vestibular DCS, 8 Ctrl+ (accident-free divers), and 22 Ctrl- (non-divers). This work demonstrates that accident-free divers have less mtDNA than non-divers, which leads to the assumption that hyperbaric exposure degrades the mtDNA. mtDNA levels are on average greater in divers with DCS compared with accident-free divers. On another hand, the amount of double strand DNA (dsDNA) is neither significantly different between controls, nor between the different DCS types. Initially the increase in circulating oligonucleotides was attributed to the destruction of cells by bubble abrasion following necrotic phenomena. If there really is a significant difference between the Medullary DCS and the Ctrl-, this difference is not significant between these same DCS and the Ctrl+. This refutes the idea of massive degassing and suggests the need for new research in order to verify that oxidative stress could be a key element without necessarily being sufficient for the occurrence of a neurological type of accident.
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Affiliation(s)
- Jean-Eric Blatteau
- Institut de Recherche Biomédicale des Armées, Equipe Résidante de Recherche Subaquatique Opérationnelle, Département Environnement Opérationnel, Unité Environnements Extrêmes, Toulon, France
- Hôpital d’Instruction des Armées – Service de Médecine Hyperbare et Expertise Plongée, Toulon, France
| | | | - Sébastien De Maistre
- Hôpital d’Instruction des Armées – Service de Médecine Hyperbare et Expertise Plongée, Toulon, France
| | - Simone Richard
- Mediterranean Institute of Oceanography, Université de Toulon, Toulon, France
| | - Pierre Louges
- Hôpital d’Instruction des Armées – Service de Médecine Hyperbare et Expertise Plongée, Toulon, France
| | - Emmanuel Gempp
- Hôpital d’Instruction des Armées – Service de Médecine Hyperbare et Expertise Plongée, Toulon, France
| | - Arnaud Druelles
- Hôpital d’Instruction des Armées – Service de Médecine Hyperbare et Expertise Plongée, Toulon, France
| | - Henri Lehot
- Hôpital d’Instruction des Armées – Service de Médecine Hyperbare et Expertise Plongée, Toulon, France
| | - Jean Morin
- Hôpital d’Instruction des Armées – Service de Médecine Hyperbare et Expertise Plongée, Toulon, France
| | - Olivier Castagna
- Institut de Recherche Biomédicale des Armées, Equipe Résidante de Recherche Subaquatique Opérationnelle, Département Environnement Opérationnel, Unité Environnements Extrêmes, Toulon, France
| | - Jacques H. Abraini
- Institut de Recherche Biomédicale des Armées, Equipe Résidante de Recherche Subaquatique Opérationnelle, Département Environnement Opérationnel, Unité Environnements Extrêmes, Toulon, France
| | - Jean-Jacques Risso
- Institut de Recherche Biomédicale des Armées, Equipe Résidante de Recherche Subaquatique Opérationnelle, Département Environnement Opérationnel, Unité Environnements Extrêmes, Toulon, France
| | - Nicolas Vallée
- Institut de Recherche Biomédicale des Armées, Equipe Résidante de Recherche Subaquatique Opérationnelle, Département Environnement Opérationnel, Unité Environnements Extrêmes, Toulon, France
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13
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Chen L, Xia HF, Shang Y, Yao SL. Molecular Mechanisms of Ventilator-Induced Lung Injury. Chin Med J (Engl) 2018; 131:1225-1231. [PMID: 29553050 PMCID: PMC5956775 DOI: 10.4103/0366-6999.226840] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Indexed: 12/22/2022] Open
Abstract
OBJECTIVE Mechanical ventilation (MV) has long been used as a life-sustaining approach for several decades. However, researchers realized that MV not only brings benefits to patients but also cause lung injury if used improperly, which is termed as ventilator-induced lung injury (VILI). This review aimed to discuss the pathogenesis of VILI and the underlying molecular mechanisms. DATA SOURCES This review was based on articles in the PubMed database up to December 2017 using the following keywords: "ventilator-induced lung injury", "pathogenesis", "mechanism", and "biotrauma". STUDY SELECTION Original articles and reviews pertaining to mechanisms of VILI were included and reviewed. RESULTS The pathogenesis of VILI was defined gradually, from traditional pathological mechanisms (barotrauma, volutrauma, and atelectrauma) to biotrauma. High airway pressure and transpulmonary pressure or cyclic opening and collapse of alveoli were thought to be the mechanisms of barotraumas, volutrauma, and atelectrauma. In the past two decades, accumulating evidence have addressed the importance of biotrauma during VILI, the molecular mechanism underlying biotrauma included but not limited to proinflammatory cytokines release, reactive oxygen species production, complement activation as well as mechanotransduction. CONCLUSIONS Barotrauma, volutrauma, atelectrauma, and biotrauma contribute to VILI, and the molecular mechanisms are being clarified gradually. More studies are warranted to figure out how to minimize lung injury induced by MV.
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Affiliation(s)
- Lin Chen
- Department of Anesthesiology, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China
| | - Hai-Fa Xia
- Department of Anesthesiology, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China
| | - You Shang
- Department of Critical Care Medicine, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China
| | - Shang-Long Yao
- Department of Anesthesiology, Institute of Anesthesiology and Critical Care Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China
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14
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Olschewski A, Veale EL, Nagy BM, Nagaraj C, Kwapiszewska G, Antigny F, Lambert M, Humbert M, Czirják G, Enyedi P, Mathie A. TASK-1 (KCNK3) channels in the lung: from cell biology to clinical implications. Eur Respir J 2017; 50:50/5/1700754. [PMID: 29122916 DOI: 10.1183/13993003.00754-2017] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 08/05/2017] [Indexed: 12/18/2022]
Abstract
TWIK-related acid-sensitive potassium channel 1 (TASK-1 encoded by KCNK3) belongs to the family of two-pore domain potassium channels. This gene subfamily is constitutively active at physiological resting membrane potentials in excitable cells, including smooth muscle cells, and has been particularly linked to the human pulmonary circulation. TASK-1 channels are sensitive to a wide array of physiological and pharmacological mediators that affect their activity such as unsaturated fatty acids, extracellular pH, hypoxia, anaesthetics and intracellular signalling pathways. Recent studies show that modulation of TASK-1 channels, either directly or indirectly by targeting their regulatory mechanisms, has the potential to control pulmonary arterial tone in humans. Furthermore, mutations in KCNK3 have been identified as a rare cause of both familial and idiopathic pulmonary arterial hypertension. This review summarises our current state of knowledge of the functional role of TASK-1 channels in the pulmonary circulation in health and disease, with special emphasis on current advancements in the field.
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Affiliation(s)
- Andrea Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research Graz, Graz, Austria .,Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Emma L Veale
- Medway School of Pharmacy, University of Kent, Central Avenue, Chatham Maritime, UK
| | - Bence M Nagy
- Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Chandran Nagaraj
- Ludwig Boltzmann Institute for Lung Vascular Research Graz, Graz, Austria.,Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Grazyna Kwapiszewska
- Ludwig Boltzmann Institute for Lung Vascular Research Graz, Graz, Austria.,Institute of Physiology, Medical University of Graz, Graz, Austria
| | - Fabrice Antigny
- Univ. Paris-Sud, Faculté de Médecine, Kremlin-Bicêtre, France.,AP-HP, Centre de Référence de l'Hypertension Pulmonaire Sévère, Département Hospitalo-Universitaire (DHU) Thorax Innovation, Service de Pneumologie et Réanimation Respiratoire, Hôpital de Bicêtre, Le Kremlin-Bicêtre, France.,UMRS 999, INSERM and Univ. Paris-Sud, Laboratoire d'Excellence (LabEx) en Recherche sur le Médicament et l'Innovation Thérapeutique (LERMIT), Hôpital-Marie-Lannelongue, Le Plessis Robinson, France
| | - Mélanie Lambert
- Univ. Paris-Sud, Faculté de Médecine, Kremlin-Bicêtre, France.,AP-HP, Centre de Référence de l'Hypertension Pulmonaire Sévère, Département Hospitalo-Universitaire (DHU) Thorax Innovation, Service de Pneumologie et Réanimation Respiratoire, Hôpital de Bicêtre, Le Kremlin-Bicêtre, France.,UMRS 999, INSERM and Univ. Paris-Sud, Laboratoire d'Excellence (LabEx) en Recherche sur le Médicament et l'Innovation Thérapeutique (LERMIT), Hôpital-Marie-Lannelongue, Le Plessis Robinson, France
| | - Marc Humbert
- Univ. Paris-Sud, Faculté de Médecine, Kremlin-Bicêtre, France.,AP-HP, Centre de Référence de l'Hypertension Pulmonaire Sévère, Département Hospitalo-Universitaire (DHU) Thorax Innovation, Service de Pneumologie et Réanimation Respiratoire, Hôpital de Bicêtre, Le Kremlin-Bicêtre, France.,UMRS 999, INSERM and Univ. Paris-Sud, Laboratoire d'Excellence (LabEx) en Recherche sur le Médicament et l'Innovation Thérapeutique (LERMIT), Hôpital-Marie-Lannelongue, Le Plessis Robinson, France
| | - Gábor Czirják
- Dept of Physiology, Semmelweis University, Budapest, Hungary
| | - Péter Enyedi
- Dept of Physiology, Semmelweis University, Budapest, Hungary
| | - Alistair Mathie
- Medway School of Pharmacy, University of Kent, Central Avenue, Chatham Maritime, UK
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15
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Bartoszewski R, Matalon S, Collawn JF. Ion channels of the lung and their role in disease pathogenesis. Am J Physiol Lung Cell Mol Physiol 2017; 313:L859-L872. [PMID: 29025712 PMCID: PMC5792182 DOI: 10.1152/ajplung.00285.2017] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 10/03/2017] [Accepted: 10/03/2017] [Indexed: 12/16/2022] Open
Abstract
Maintenance of normal epithelial ion and water transport in the lungs includes providing a thin layer of surface liquid that coats the conducting airways. This airway surface liquid is critical for normal lung function in a number of ways but, perhaps most importantly, is required for normal mucociliary clearance and bacterial removal. Preservation of the appropriate level of hydration, pH, and viscosity for the airway surface liquid requires the proper regulation and function of a battery of different types of ion channels and transporters. Here we discuss how alterations in ion channel/transporter function often lead to lung pathologies.
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Affiliation(s)
- Rafal Bartoszewski
- Department of Biology and Pharmaceutical Botany, Medical University of Gdansk, Gdansk, Poland
| | - Sadis Matalon
- Department of Anesthesiology and Perioperative Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Cell, Developmental, and Integrative Biology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
- Pulmonary Injury and Repair Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and
- Gregory Fleming James Cystic Fibrosis Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - James F Collawn
- Department of Cell, Developmental, and Integrative Biology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama;
- Pulmonary Injury and Repair Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; and
- Gregory Fleming James Cystic Fibrosis Center, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
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16
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Heidemann SM, Nair A, Bulut Y, Sapru A. Pathophysiology and Management of Acute Respiratory Distress Syndrome in Children. Pediatr Clin North Am 2017; 64:1017-1037. [PMID: 28941533 PMCID: PMC9683071 DOI: 10.1016/j.pcl.2017.06.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Acute respiratory distress syndrome (ARDS) is a syndrome of noncardiogenic pulmonary edema and hypoxia that accompanies up to 30% of deaths in pediatric intensive care units. Pediatric ARDS (PARDS) is diagnosed by the presence of hypoxia, defined by oxygenation index or Pao2/Fio2 ratio cutoffs, and new chest infiltrate occurring within 7 days of a known insult. Hallmarks of ARDS include hypoxemia and decreased lung compliance, increased work of breathing, and impaired gas exchange. Mortality is often accompanied by multiple organ failure. Although many modalities to treat PARDS have been investigated, supportive therapies and lung protective ventilator support remain the mainstay.
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Affiliation(s)
| | - Alison Nair
- Department of Pediatrics, University of California, San Francisco, CA
| | - Yonca Bulut
- Department of Pediatrics, David Geffen School of Medicine, University of California Los Angeles, CA
| | - Anil Sapru
- Department of Pediatrics, University of California, San Francisco, 550 16th Street, Box 0110 San Francisco, CA 94143, USA; Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
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17
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Schwingshackl A, Lopez B, Teng B, Luellen C, Lesage F, Belperio J, Olcese R, Waters CM. Hyperoxia treatment of TREK-1/TREK-2/TRAAK-deficient mice is associated with a reduction in surfactant proteins. Am J Physiol Lung Cell Mol Physiol 2017; 313:L1030-L1046. [PMID: 28839101 DOI: 10.1152/ajplung.00121.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 08/15/2017] [Accepted: 08/16/2017] [Indexed: 12/29/2022] Open
Abstract
We previously proposed a role for the two-pore domain potassium (K2P) channel TREK-1 in hyperoxia (HO)-induced lung injury. To determine whether redundancy among the three TREK isoforms (TREK-1, TREK-2, and TRAAK) could protect from HO-induced injury, we now examined the effect of deletion of all three TREK isoforms in a clinically relevant scenario of prolonged HO exposure and mechanical ventilation (MV). We exposed WT and TREK-1/TREK-2/TRAAK-deficient [triple knockout (KO)] mice to either room air, 72-h HO, MV [high and low tidal volume (TV)], or a combination of HO + MV and measured quasistatic lung compliance, bronchoalveolar lavage (BAL) protein concentration, histologic lung injury scores (LIS), cellular apoptosis, and cytokine levels. We determined surfactant gene and protein expression and attempted to prevent HO-induced lung injury by prophylactically administering an exogenous surfactant (Curosurf). HO treatment increased lung injury in triple KO but not WT mice, including an elevated LIS, BAL protein concentration, and markers of apoptosis, decreased lung compliance, and a more proinflammatory cytokine phenotype. MV alone had no effect on lung injury markers. Exposure to HO + MV (low TV) further decreased lung compliance in triple KO but not WT mice, and HO + MV (high TV) was lethal for triple KO mice. In triple KO mice, the HO-induced lung injury was associated with decreased surfactant protein (SP) A and SPC but not SPB and SPD expression. However, these changes could not be explained by alterations in the transcription factors nuclear factor-1 (NF-1), NKX2.1/thyroid transcription factor-1 (TTF-1) or c-jun, or lamellar body levels. Prophylactic Curosurf administration did not improve lung injury scores or compliance in triple KO mice.
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Affiliation(s)
| | - Benjamin Lopez
- Department of Pediatrics, University of California, Los Angeles, California
| | - Bin Teng
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Charlean Luellen
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Florian Lesage
- Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Laboratory of Excellence "Ion Channel Science and Therapeutics," Valbonne, France
| | - John Belperio
- Department of Pulmonary and Critical Care, University of California, Los Angeles, California
| | - Riccardo Olcese
- Department of Anesthesiology and Perioperative Medicine, University of California, Los Angeles, California
| | - Christopher M Waters
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee; and
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18
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Zhang C, Deng Y, Lei Y, Zhao J, Wei W, Li Y. Effects of selenium on myocardial apoptosis by modifying the activity of mitochondrial STAT3 and regulating potassium channel expression. Exp Ther Med 2017; 14:2201-2205. [PMID: 28962142 PMCID: PMC5609099 DOI: 10.3892/etm.2017.4716] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 06/19/2017] [Indexed: 01/21/2023] Open
Abstract
The present study investigated the effects of myocardial mitochondrial signal transduction and activator of transcription 3 (STAT3), succinate dehydrogenase activity and changes of potassium channel expression on cardiomyocyte apoptosis under low selenium conditions. Primary cultured cardiomyocytes from neonatal mice were divided into the non-toxic control group (0.1 µM sodium selenite) and low selenium treatment group (0.05 µM sodium selenite) according to different selenium concentrations. The expression of mitochondrial STAT3, p-STAT3, p-Kv1.2 potassium channel and apoptosis-related proteins, Bax and Bcl-2, were assessed by immunoblotting. Succinate dehydrogenase activity was measured by spectrophotometry. Flow cytometry was used to detect cardiomyocyte apoptosis. Low selenium treatment reduced the expression of p-STAT3, but did not affect the expression of STAT3. In addition, low selenium treatment reduced the activity of mitochondrial STAT3 and succinate dehydrogenase in cardiomyocytes, leading to injury of myocardial mitochondria. Compared with the control group, low selenium conditions reduced the activity of p-Kv1.2 and reduced the normal electrophysiological function of cardiomyocytes. In the low selenium-treated group, the expression of Bax protein increased, whereas the expression of Bcl-2 protein decreased. The apoptotic rate increased. In conclusion, selenium deficiency in cardiomyocytes leads to decreased potassium channel expression and decreased mitochondrial STAT3 activity and mitochondrial function, which in turn promotes the apoptosis of cardiomyocytes.
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Affiliation(s)
- Changjiang Zhang
- Cardiovascular Disease Center, Central Hospital of Enshi Autonomous Prefecture, Enshi, Hubei 445000, P.R. China
| | - Yinzhi Deng
- Department of Gastroenterology, Central Hospital of Enshi Autonomous Prefecture, Enshi, Hubei 445000, P.R. China
| | - Yuhua Lei
- Cardiovascular Disease Center, Central Hospital of Enshi Autonomous Prefecture, Enshi, Hubei 445000, P.R. China
| | - Jingbo Zhao
- Cardiovascular Disease Center, Central Hospital of Enshi Autonomous Prefecture, Enshi, Hubei 445000, P.R. China
| | - Wen Wei
- Cardiovascular Disease Center, Central Hospital of Enshi Autonomous Prefecture, Enshi, Hubei 445000, P.R. China
| | - Yuanhong Li
- Cardiovascular Disease Center, Central Hospital of Enshi Autonomous Prefecture, Enshi, Hubei 445000, P.R. China
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19
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Schwingshackl A. The role of stretch-activated ion channels in acute respiratory distress syndrome: finally a new target? Am J Physiol Lung Cell Mol Physiol 2016; 311:L639-52. [PMID: 27521425 DOI: 10.1152/ajplung.00458.2015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 08/05/2016] [Indexed: 02/06/2023] Open
Abstract
Mechanical ventilation (MV) and oxygen therapy (hyperoxia; HO) comprise the cornerstones of life-saving interventions for patients with acute respiratory distress syndrome (ARDS). Unfortunately, the side effects of MV and HO include exacerbation of lung injury by barotrauma, volutrauma, and propagation of lung inflammation. Despite significant improvements in ventilator technologies and a heightened awareness of oxygen toxicity, besides low tidal volume ventilation few if any medical interventions have improved ARDS outcomes over the past two decades. We are lacking a comprehensive understanding of mechanotransduction processes in the healthy lung and know little about the interactions between simultaneously activated stretch-, HO-, and cytokine-induced signaling cascades in ARDS. Nevertheless, as we are unraveling these mechanisms we are gathering increasing evidence for the importance of stretch-activated ion channels (SACs) in the activation of lung-resident and inflammatory cells. In addition to the discovery of new SAC families in the lung, e.g., two-pore domain potassium channels, we are increasingly assigning mechanosensing properties to already known Na(+), Ca(2+), K(+), and Cl(-) channels. Better insights into the mechanotransduction mechanisms of SACs will improve our understanding of the pathways leading to ventilator-induced lung injury and lead to much needed novel therapeutic approaches against ARDS by specifically targeting SACs. This review 1) summarizes the reasons why the time has come to seriously consider SACs as new therapeutic targets against ARDS, 2) critically analyzes the physiological and experimental factors that currently limit our knowledge about SACs, and 3) outlines the most important questions future research studies need to address.
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20
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Schwingshackl A, Roan E, Teng B, Waters CM. TREK-1 Regulates Cytokine Secretion from Cultured Human Alveolar Epithelial Cells Independently of Cytoskeletal Rearrangements. PLoS One 2015; 10:e0126781. [PMID: 26001192 PMCID: PMC4441361 DOI: 10.1371/journal.pone.0126781] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 03/28/2015] [Indexed: 01/15/2023] Open
Abstract
Background TREK-1 deficient alveolar epithelial cells (AECs) secrete less IL-6, more MCP-1, and contain less F-actin. Whether these alterations in cytokine secretion and F-actin content are related remains unknown. We now hypothesized that cytokine secretion from TREK-1-deficient AECs was regulated by cytoskeletal rearrangements. Methods We determined F-actin and α-tubulin contents of control, TREK-1-deficient and TREK-1-overexpressing human A549 cells by confocal microscopy and western blotting, and measured IL-6 and MCP-1 levels using real-time PCR and ELISA. Results Cytochalasin D decreased the F-actin content of control cells. Jasplakinolide increased the F-actin content of TREK-1 deficient cells, similar to the effect of TREK-1 overexpression in control cells. Treatment of control and TREK-1 deficient cells with TNF-α, a strong stimulus for IL-6 and MCP-1 secretion, had no effect on F-actin structures. The combination of TNF-α+cytochalasin D or TNF-α+jasplakinolide had no additional effect on the F-actin content or architecture when compared to cytochalasin D or jasplakinolide alone. Although TREK-1 deficient AECs contained less F-actin at baseline, quantified biochemically, they contained more α-tubulin. Exposure to nocodazole disrupted α-tubulin filaments in control and TREK-1 deficient cells, but left the overall amount of α-tubulin unchanged. Although TNF-α had no effect on the F-actin or α-tubulin contents, it increased IL-6 and MCP-1 production and secretion from control and TREK-1 deficient cells. IL-6 and MCP-1 secretions from control and TREK-1 deficient cells after TNF-α+jasplakinolide or TNF-α+nocodazole treatment was similar to the effect of TNF-α alone. Interestingly, cytochalasin D decreased TNF-α-induced IL-6 but not MCP-1 secretion from control but not TREK-1 deficient cells. Conclusion Although cytochalasin D, jasplakinolide and nocodazole altered the F-actin and α-tubulin structures of control and TREK-1 deficient AEC, the changes in cytokine secretion from TREK-1 deficient cells cannot be explained by cytoskeletal rearrangements in these cells.
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Affiliation(s)
- Andreas Schwingshackl
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, United States of America
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, United States of America
- * E-mail:
| | - Esra Roan
- Department of Biomedical Engineering, University of Memphis, Memphis, TN, United States of America
| | - Bin Teng
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, United States of America
| | - Christopher M. Waters
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, United States of America
- Department of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States of America
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Trek1 contributes to maintaining nasal epithelial barrier integrity. Sci Rep 2015; 5:9191. [PMID: 25778785 PMCID: PMC7365316 DOI: 10.1038/srep09191] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 02/24/2015] [Indexed: 02/07/2023] Open
Abstract
Epithelial barrier integrity is critical to maintain the homeostasis in the body. The regulatory mechanism of the epithelial barrier function has not been fully understood. This study aims to elucidate the role of the TWIK-related potassium channel-1 (Trek1) in the regulation of the epithelial barrier function of the nasal mucosa. In this study, the levels of Trek1 were assessed by real time RT-PCR and Western blotting. The epithelial barrier function of the rat nasal epithelia was evaluated by the Ussing chamber system. The results showed that Trek1 was detected in the human and rat nasal epithelia, which were significantly lower in patients and rats with allergic rhinitis than that in healthy controls. Exposure to the signature T helper 2 cytokine, interleukin (IL)-4, markedly suppressed the expression of Trek1 in the nasal mucosa via up regulating the expression of the histone deacetylase (HDAC)1. The IL-4-induced rat nasal epithelial barrier dysfunction could be blocked by HDAC1 inhibitor (Trichostatin A), or sodium butyrate, or administration of Clostridium Butyricum. We conclude that Trek1 is critical to maintain the nasal epithelial barrier function.
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Brune K, Frank J, Schwingshackl A, Finigan J, Sidhaye VK. Pulmonary epithelial barrier function: some new players and mechanisms. Am J Physiol Lung Cell Mol Physiol 2015; 308:L731-45. [PMID: 25637609 DOI: 10.1152/ajplung.00309.2014] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/27/2015] [Indexed: 12/20/2022] Open
Abstract
The pulmonary epithelium serves as a barrier to prevent access of the inspired luminal contents to the subepithelium. In addition, the epithelium dictates the initial responses of the lung to both infectious and noninfectious stimuli. One mechanism by which the epithelium does this is by coordinating transport of diffusible molecules across the epithelial barrier, both through the cell and between cells. In this review, we will discuss a few emerging paradigms of permeability changes through altered ion transport and paracellular regulation by which the epithelium gates its response to potentially detrimental luminal stimuli. This review is a summary of talks presented during a symposium in Experimental Biology geared toward novel and less recognized methods of epithelial barrier regulation. First, we will discuss mechanisms of dynamic regulation of cell-cell contacts in the context of repetitive exposure to inhaled infectious and noninfectious insults. In the second section, we will briefly discuss mechanisms of transcellular ion homeostasis specifically focused on the role of claudins and paracellular ion-channel regulation in chronic barrier dysfunction. In the next section, we will address transcellular ion transport and highlight the role of Trek-1 in epithelial responses to lung injury. In the final section, we will outline the role of epithelial growth receptor in barrier regulation in baseline, acute lung injury, and airway disease. We will then end with a summary of mechanisms of epithelial control as well as discuss emerging paradigms of the epithelium role in shifting between a structural element that maintains tight cell-cell adhesion to a cell that initiates and participates in immune responses.
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Affiliation(s)
- Kieran Brune
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland
| | - James Frank
- The Division of Pulmonary and Critical Care Medicine, University of California, San Francisco, San Francisco VA Medical Center, and NCIRE/Veterans Health Research Institute, San Francisco, California
| | - Andreas Schwingshackl
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, Tennessee
| | - James Finigan
- Division of Oncology, Cancer Center, National Jewish Health, Denver, Colorado
| | - Venkataramana K Sidhaye
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland;
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