1
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Du C, Chen L, Liu G, Yuan F, Zhang Z, Rong M, Mo G, Liu C. Tick-Derived Peptide Blocks Potassium Channel TREK-1. Int J Mol Sci 2024; 25:8377. [PMID: 39125945 PMCID: PMC11312834 DOI: 10.3390/ijms25158377] [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: 06/28/2024] [Revised: 07/27/2024] [Accepted: 07/29/2024] [Indexed: 08/12/2024] Open
Abstract
Ticks transmit a variety of pathogens, including rickettsia and viruses, when they feed on blood, afflicting humans and other animals. Bioactive components acting on inflammation, coagulation, and the immune system were reported to facilitate ticks' ability to suck blood and transmit tick-borne diseases. In this study, a novel peptide, IstTx, from an Ixodes scapularis cDNA library was analyzed. The peptide IstTx, obtained by recombinant expression and purification, selectively inhibited a potassium channel, TREK-1, in a dose-dependent manner, with an IC50 of 23.46 ± 0.22 μM. The peptide IstTx exhibited different characteristics from fluoxetine, and the possible interaction of the peptide IstTx binding to the channel was explored by molecular docking. Notably, extracellular acidification raised its inhibitory efficacy on the TREK-1 channel. Our results found that the tick-derived peptide IstTx blocked the TREK-1 channel and provided a novel tool acting on the potassium channel.
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Affiliation(s)
- Canwei Du
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Linyan Chen
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Guohao Liu
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Fuchu Yuan
- National & Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410006, China
| | - Zheyang Zhang
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
| | - Mingqiang Rong
- National & Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha 410006, China
- Frontiers Medical Center, Tianfu Jincheng Laboratory, No. 387-201 Heming Street, Chengdu 610212, China
| | - Guoxiang Mo
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Changjun Liu
- School of Life and Health Sciences, Hunan University of Science and Technology, Xiangtan 411201, China
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2
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Bechard E, Arel E, Bride J, Louradour J, Bussy X, Elloumi A, Vigor C, Soule P, Oger C, Galano JM, Durand T, Le Guennec JY, Moha-Ou-Maati H, Demion M. Activation of hTREK-1 by polyunsaturated fatty acids involves direct interaction. Sci Rep 2024; 14:15244. [PMID: 38956407 PMCID: PMC11220079 DOI: 10.1038/s41598-024-66192-w] [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: 12/21/2023] [Accepted: 06/28/2024] [Indexed: 07/04/2024] Open
Abstract
TREK-1 is a mechanosensitive channel activated by polyunsaturated fatty acids (PUFAs). Its activation is supposed to be linked to changes in membrane tension following PUFAs insertion. Here, we compared the effect of 11 fatty acids and ML402 on TREK-1 channel activation using the whole cell and the inside-out configurations of the patch-clamp technique. Firstly, TREK-1 activation by PUFAs is variable and related to the variable constitutive activity of TREK-1. We observed no correlation between TREK-1 activation and acyl chain length or number of double bonds suggesting that the bilayer-couple hypothesis cannot explain by itself the activation of TREK-1 by PUFAs. The membrane fluidity measurement is not modified by PUFAs at 10 µM. The spectral shift analysis in TREK-1-enriched microsomes indicates a KD,TREK1 at 44 µM of C22:6 n-3. PUFAs display the same activation and reversible kinetics than the direct activator ML402 and activate TREK-1 in both whole-cell and inside-out configurations of patch-clamp suggesting that the binding site of PUFAs is accessible from both sides of the membrane, as for ML402. Finally, we proposed a two steps mechanism: first, insertion into the membrane, with no fluidity or curvature modifications at 10 µM, and then interaction with TREK-1 channel to open it.
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Affiliation(s)
- Emilie Bechard
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France
| | - Elodie Arel
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France
| | - Jamie Bride
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France
| | - Julien Louradour
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France
| | - Xavier Bussy
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France
| | - Anis Elloumi
- IBMM, Université de Montpellier, UMR CNRS 5247, ENSCM, Montpellier, France
| | - Claire Vigor
- IBMM, Université de Montpellier, UMR CNRS 5247, ENSCM, Montpellier, France
| | | | - Camille Oger
- IBMM, Université de Montpellier, UMR CNRS 5247, ENSCM, Montpellier, France
| | - Jean-Marie Galano
- IBMM, Université de Montpellier, UMR CNRS 5247, ENSCM, Montpellier, France
| | - Thierry Durand
- IBMM, Université de Montpellier, UMR CNRS 5247, ENSCM, Montpellier, France
| | - Jean-Yves Le Guennec
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France
| | - Hamid Moha-Ou-Maati
- IGF, Université de Montpellier, UMR CNRS 5203, Inserm 1191, Montpellier, France
- INM, Inserm U1298, Montpellier, France
| | - Marie Demion
- PhyMedExp, Université de Montpellier, Inserm U1046, UMR CNRS 9412, CHU Arnaud de Villeneuve, Bâtiment Craste de Paulet, 370 Avenue du Doyen Gaston Giraud, 34290, Montpellier Cedex 05, France.
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3
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Roy-Chowdhury S, Jang S, Abderemane-Ali F, Naughton F, Grabe M, Minor DL. Structure of the human K 2P13.1(THIK-1) channel reveals a novel hydrophilic pore restriction and lipid cofactor site. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.26.600491. [PMID: 38979306 PMCID: PMC11230452 DOI: 10.1101/2024.06.26.600491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
The halothane-inhibited K2P leak potassium channel K2P13.1 (THIK-1)1-3 is found in diverse cells1,4 including neurons1,5 and microglia6-8 where it affects surveillance6, synaptic pruning7, phagocytosis7, and inflammasome-mediated interleukin-1β release6,8,9. As with many K2Ps1,5,10-14 and other voltage-gated ion channel (VGIC) superfamily members3,15,16, polyunsaturated fatty acid (PUFA) lipids modulate K2P13.1 (THIK-1)1,5,14,17 via a poorly understood mechanism. Here, we present cryo-electronmicroscopy (cryo-EM) structures of human K2P13.1 (THIK-1) and mutants in lipid nanodiscs and detergent. These reveal that, unlike other K2Ps13,18-24, K2P13.1 (THIK-1) has a two-chamber aqueous inner cavity obstructed by a M4 transmembrane helix tyrosine (Tyr273, the flow restrictor). This hydrophilic barrier can be opened by an activatory mutation, S136P25, at natural break in the M2 transmembrane helix and by intrinsic channel dynamics. The structures also reveal a buried lipid in the P1/M4 intersubunit interface at a location, the PUFA site, that coincides with the TREK subfamily K2P modulator pocket for small molecule agonists18,26,27. This overlap, together with the effects of mutation on K2P13.1 (THIK-1) PUFA responses, indicates that the PUFA site lipids are K2P13.1 (THIK-1) cofactors. Comparison with the PUFA-responsive VGIC Kv7.1 (KCNQ1)28-31 reveals a shared role for the equivalent pore domain intersubunit interface in lipid modulation, providing a framework for dissecting the effects of PUFAs on the VGIC superfamily. Our findings reveal the unique architecture underlying K2P13.1 (THIK-1) function, highlight the importance of the P1/M4 interface in control of K2Ps by both natural and synthetic agents, and should aid development of THIK subfamily modulators for diseases such as neuroinflammation6,32 and autism6.
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Affiliation(s)
- Shatabdi Roy-Chowdhury
- Cardiovascular Research Institute, University of California, San Francisco, California 93858-2330 USA
| | - Seil Jang
- Cardiovascular Research Institute, University of California, San Francisco, California 93858-2330 USA
| | - Fayal Abderemane-Ali
- Cardiovascular Research Institute, University of California, San Francisco, California 93858-2330 USA
| | - Fiona Naughton
- Cardiovascular Research Institute, University of California, San Francisco, California 93858-2330 USA
| | - Michael Grabe
- Cardiovascular Research Institute, University of California, San Francisco, California 93858-2330 USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, California 93858-2330 USA
| | - Daniel L. Minor
- Cardiovascular Research Institute, University of California, San Francisco, California 93858-2330 USA
- Departments of Biochemistry and Biophysics, and Cellular and Molecular Pharmacology, University of California, San Francisco, California 93858-2330 USA
- California Institute for Quantitative Biomedical Research, University of California, San Francisco, California 93858-2330 USA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, California 93858-2330 USA
- Molecular Biophysics and Integrated Bio-imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 USA
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4
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Pang JJ. The Variety of Mechanosensitive Ion Channels in Retinal Neurons. Int J Mol Sci 2024; 25:4877. [PMID: 38732096 PMCID: PMC11084373 DOI: 10.3390/ijms25094877] [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: 02/27/2024] [Revised: 04/16/2024] [Accepted: 04/20/2024] [Indexed: 05/13/2024] Open
Abstract
Alterations in intraocular and external pressure critically involve the pathogenesis of glaucoma, traumatic retinal injury (TRI), and other retinal disorders, and retinal neurons have been reported to express multiple mechanical-sensitive channels (MSCs) in recent decades. However, the role of MSCs in visual functions and pressure-related retinal conditions has been unclear. This review will focus on the variety and functional significance of the MSCs permeable to K+, Na+, and Ca2+, primarily including the big potassium channel (BK); the two-pore domain potassium channels TRAAK and TREK; Piezo; the epithelial sodium channel (ENaC); and the transient receptor potential channels vanilloid TRPV1, TRPV2, and TRPV4 in retinal photoreceptors, bipolar cells, horizontal cells, amacrine cells, and ganglion cells. Most MSCs do not directly mediate visual signals in vertebrate retinas. On the other hand, some studies have shown that MSCs can open in physiological conditions and regulate the activities of retinal neurons. While these data reasonably predict the crossing of visual and mechanical signals, how retinal light pathways deal with endogenous and exogenous mechanical stimulation is uncertain.
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Affiliation(s)
- Ji-Jie Pang
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX 77030, USA
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5
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Yu H, Wang X, Tian R, Li X, Xu C, Fei J, Li T, Yin Z. Myometrium infection decreases TREK1 through NHE1 and increases contraction in pregnant mice. Am J Physiol Cell Physiol 2024; 326:C1106-C1119. [PMID: 38344766 DOI: 10.1152/ajpcell.00598.2023] [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: 11/08/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 03/23/2024]
Abstract
Intrauterine infection during pregnancy can enhance uterine contractions. A two-pore K+ channel TREK1 is crucial for maintaining uterine quiescence and reducing contractility, with its properties regulated by pH changes in cell microenvironment. Meanwhile, the sodium hydrogen exchanger 1 (NHE1) plays a pivotal role in modulating cellular pH homeostasis, and its activation increases smooth muscle tension. By establishing an infected mouse model of Escherichia coli (E. coli) and lipopolysaccharide (LPS), we used Western blotting, real-time quantitative polymerase chain reaction, and immunofluorescence to detect changes of TREK1 and NHE1 expression in the myometrium, and isometric recording measured the uterus contraction. The NHE1 inhibitor cariporide was used to explore the effect of NHE1 on TREK1. Finally, cell contraction assay and siRNA transfection were performed to clarify the relationship between NHE1 and TREK1 in vitro. We found that the uterine contraction was notably enhanced in infected mice with E. coli and LPS administration. Meanwhile, TREK1 expression was reduced, whereas NHE1 expression was upregulated in infected mice. Cariporide alleviated the increased uterine contraction and promoted myometrium TREK1 expression in LPS-injected mice. Furthermore, suppression of NHE1 with siRNA transfection inhibited the contractility of uterine smooth muscle cells and activated the TREK1. Altogether, our findings indicate that infection increases the uterine contraction by downregulating myometrium TREK1 in mice, and the inhibition of TREK1 is attributed to the activation of NHE1.NEW & NOTEWORTHY Present work found that infection during pregnancy will increase myometrium contraction. Infection downregulated NHE1 and followed TREK1 expression and activation decrease in myometrium, resulting in increased myometrium contraction.
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Affiliation(s)
- Huihui Yu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xingxing Wang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Ruixian Tian
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Xuan Li
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Chenyi Xu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Jiajia Fei
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, China
| | - Tengteng Li
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Zongzhi Yin
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Anhui Medical University, Hefei, China
- NHC Key Laboratory of Study on Abnormal Gametes and Reproductive Tract, Anhui Medical University, Hefei, China
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6
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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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7
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Zhu Y, Yun SD, Zhang T, Chang JY, Stover L, Laganowsky A. Native mass spectrometry of proteoliposomes containing integral and peripheral membrane proteins. Chem Sci 2023; 14:14243-14255. [PMID: 38098719 PMCID: PMC10718073 DOI: 10.1039/d3sc04938h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 11/18/2023] [Indexed: 12/17/2023] Open
Abstract
Cellular membranes are critical to the function of membrane proteins, whether they are associated (peripheral) or embedded (integral) within the bilayer. While detergents have contributed to our understanding of membrane protein structure and function, there remains challenges in characterizing protein-lipid interactions within the context of an intact membrane. Here, we developed a method to prepare proteoliposomes for native mass spectrometry (MS) studies. We first use native MS to detect the encapsulation of soluble proteins within liposomes. We then find the peripheral Gβ1γ2 complex associated with the membrane can be ejected and analyzed using native MS. Four different integral membrane proteins (AmtB, AqpZ, TRAAK, and TREK2), all of which have previously been characterized in detergent, eject from the proteoliposomes as intact complexes bound to lipids that have been shown to tightly associate in detergent, drawing a correlation between the two approaches. We also show the utility of more complex lipid environments, such as a brain polar lipid extract, and show TRAAK ejects from liposomes of this extract bound to lipids. These findings underscore the capability to eject protein complexes from membranes bound to both lipids and metal ions, and this approach will be instrumental in the identification of key protein-lipid interactions.
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Affiliation(s)
- Yun Zhu
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Sangho D Yun
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Tianqi Zhang
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Jing-Yuan Chang
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Lauren Stover
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
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8
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Coppola T, Daziano G, Legroux I, Béraud-Dufour S, Blondeau N, Lebrun P. Unlocking Therapeutic Synergy: Tailoring Drugs for Comorbidities such as Depression and Diabetes through Identical Molecular Targets in Different Cell Types. Cells 2023; 12:2768. [PMID: 38067196 PMCID: PMC10706795 DOI: 10.3390/cells12232768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/24/2023] [Accepted: 12/01/2023] [Indexed: 12/18/2023] Open
Abstract
Research in the field of pharmacology aims to generate new treatments for pathologies. Nowadays, there are an increased number of chronic disorders that severely and durably handicap many patients. Among the most widespread pathologies, obesity, which is often associated with diabetes, is constantly increasing in incidence, and in parallel, neurodegenerative and mood disorders are increasingly affecting many people. For years, these pathologies have been so frequently observed in the population in a concomitant way that they are considered as comorbidities. In fact, common mechanisms are certainly at work in the etiology of these pathologies. The main purpose of this review is to show the value of anticipating the effect of baseline treatment of a condition on its comorbidity in order to obtain concomitant positive actions. One of the implications would be that by understanding and targeting shared molecular mechanisms underlying these conditions, it may be possible to tailor drugs that address both simultaneously. To this end, we firstly remind readers of the close link existing between depression and diabetes and secondly address the potential benefit of the pleiotropic actions of two major active molecules used to treat central and peripheral disorders, first a serotonin reuptake inhibitor (Prozac ®) and then GLP-1R agonists. In the second part, by discussing the therapeutic potential of new experimental antidepressant molecules, we will support the concept that a better understanding of the intracellular signaling pathways targeted by pharmacological agents could lead to future synergistic treatments targeting solely positive effects for comorbidities.
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Affiliation(s)
- Thierry Coppola
- CNRS, IPMC, Université Côte d’Azur, Sophia Antipolis, F-06560 Valbonne, France; (G.D.); (I.L.); (S.B.-D.); (N.B.)
| | | | | | | | | | - Patricia Lebrun
- CNRS, IPMC, Université Côte d’Azur, Sophia Antipolis, F-06560 Valbonne, France; (G.D.); (I.L.); (S.B.-D.); (N.B.)
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9
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Hori A, Fukazawa A, Katanosaka K, Mizuno M, Hotta N. Mechanosensitive channels in the mechanical component of the exercise pressor reflex. Auton Neurosci 2023; 250:103128. [PMID: 37925831 DOI: 10.1016/j.autneu.2023.103128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 11/07/2023]
Abstract
The cardiovascular response is appropriately regulated during exercise to meet the metabolic demands of the active muscles. The exercise pressor reflex is a neural feedback mechanism through thin-fiber muscle afferents activated by mechanical and metabolic stimuli in the active skeletal muscles. The mechanical component of this reflex is referred to as skeletal muscle mechanoreflex. Its initial step requires mechanotransduction mediated by mechanosensors, which convert mechanical stimuli into biological signals. Recently, various mechanosensors have been identified, and their contributions to muscle mechanoreflex have been actively investigated. Nevertheless, the mechanosensitive channels responsible for this muscular reflex remain largely unknown. This review discusses progress in our understanding of muscle mechanoreflex under healthy conditions, focusing on mechanosensitive channels.
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Affiliation(s)
- Amane Hori
- College of Life and Health Sciences, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi 487-8501, Japan; Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-8472, Japan; Department of Applied Clinical Research, UT Southwestern Medical Center, Dallas, TX 75390-9174, USA
| | - Ayumi Fukazawa
- Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-8472, Japan; Department of Applied Clinical Research, UT Southwestern Medical Center, Dallas, TX 75390-9174, USA
| | - Kimiaki Katanosaka
- College of Life and Health Sciences, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi 487-8501, Japan
| | - Masaki Mizuno
- Department of Applied Clinical Research, UT Southwestern Medical Center, Dallas, TX 75390-9174, USA
| | - Norio Hotta
- College of Life and Health Sciences, Chubu University, 1200 Matsumoto-cho, Kasugai, Aichi 487-8501, Japan.
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10
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Moschetta M, Vurro V, Sesti V, Bertarelli C, Paternò GM, Lanzani G. Modulation of Mechanosensitive Potassium Channels by a Membrane-targeted Nongenetic Photoswitch. J Phys Chem B 2023; 127:8869-8878. [PMID: 37815392 PMCID: PMC10591468 DOI: 10.1021/acs.jpcb.3c04551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 09/11/2023] [Indexed: 10/11/2023]
Abstract
Mechanosensitive ion channels are present in the plasma membranes of all cells. They play a fundamental role in converting mechanical stimuli into biochemical signals and are involved in several physiological processes such as touch sensation, hearing, and blood pressure regulation. This protein family includes TWIK-related arachidonic acid-stimulated K+ channel (TRAAK), which is specifically implicated in the maintenance of the resting membrane potential and in the regulation of a variety of important neurobiological functions. Dysregulation of these channels has been linked to various diseases, including blindness, epilepsy, cardiac arrhythmia, and chronic pain. For these reasons, mechanosensitive channels are targets for the treatment of several diseases. Here, we propose a new approach to investigate TRAAK ion channel modulation that is based on nongenetic photostimulation. We employed an amphiphilic azobenzene, named Ziapin2. In the dark, Ziapin2 preferentially dwells in the plasma membrane, causing a thinning of the membrane. Upon light irradiation, an isomerization occurs, breaking the dimers and inducing membrane relaxation. To study the effect of Ziapin2 on the mechanosensitive channels, we expressed human TRAAK (hTRAAK) channels in HEK293T cells. We observed that Ziapin2 insertion in the membrane is able per se to recruit hTRAAK, permitting the exit of K+ ions outside the cells with a consequent hyperpolarization of the cell membrane. During light stimulation, membrane relaxation induces hTRAAK closure, generating a consistent and compensatory depolarization. These results add information to the Ziapin2 mechanism and suggest that membrane deformation can be a tool for the nonselective modulation of mechanosensitive channels.
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Affiliation(s)
- Matteo Moschetta
- Center
for Nano Science and Technology, Istituto
Italiano di Tecnologia, Via Rubattino, 81, 20134 Milano, Italy
| | - Vito Vurro
- Center
for Nano Science and Technology, Istituto
Italiano di Tecnologia, Via Rubattino, 81, 20134 Milano, Italy
| | - Valentina Sesti
- Center
for Nano Science and Technology, Istituto
Italiano di Tecnologia, Via Rubattino, 81, 20134 Milano, Italy
- Department
of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Chiara Bertarelli
- Center
for Nano Science and Technology, Istituto
Italiano di Tecnologia, Via Rubattino, 81, 20134 Milano, Italy
- Department
of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Giuseppe Maria Paternò
- Center
for Nano Science and Technology, Istituto
Italiano di Tecnologia, Via Rubattino, 81, 20134 Milano, Italy
- Department
of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
| | - Guglielmo Lanzani
- Center
for Nano Science and Technology, Istituto
Italiano di Tecnologia, Via Rubattino, 81, 20134 Milano, Italy
- Department
of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy
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11
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Zhu Y, Odenkirk MT, Qiao P, Zhang T, Schrecke S, Zhou M, Marty MT, Baker ES, Laganowsky A. Combining native mass spectrometry and lipidomics to uncover specific membrane protein-lipid interactions from natural lipid sources. Chem Sci 2023; 14:8570-8582. [PMID: 37593000 PMCID: PMC10430552 DOI: 10.1039/d3sc01482g] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 07/19/2023] [Indexed: 08/19/2023] Open
Abstract
While it is known that lipids play an essential role in regulating membrane protein structure and function, it remains challenging to identify specific protein-lipid interactions. Here, we present an innovative approach that combines native mass spectrometry (MS) and lipidomics to identify lipids retained by membrane proteins from natural lipid extracts. Our results reveal that the bacterial ammonia channel (AmtB) enriches specific cardiolipin (CDL) and phosphatidylethanolamine (PE) from natural headgroup extracts. When the two extracts are mixed, AmtB retains more species, wherein selectivity is tuned to bias headgroup selection. Using a series of natural headgroup extracts, we show TRAAK, a two-pore domain K+ channel (K2P), retains specific acyl chains that is independent of the headgroup. A brain polar lipid extract was then combined with the K2Ps, TRAAK and TREK2, to understand lipid specificity. More than a hundred lipids demonstrated affinity for each protein, and both channels were found to retain specific fatty acids and lysophospholipids known to stimulate channel activity, even after several column washes. Natural lipid extracts provide the unique opportunity to not only present natural lipid diversity to purified membrane proteins but also identify lipids that may be important for membrane protein structure and function.
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Affiliation(s)
- Yun Zhu
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Melanie T Odenkirk
- Department of Chemistry, North Carolina State University Raleigh NC 27695 USA
| | - Pei Qiao
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Tianqi Zhang
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Samantha Schrecke
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
| | - Ming Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine Houston TX 77030 USA
| | - Michael T Marty
- Department of Chemistry and Biochemistry, The University of Arizona Tucson AZ 85721 USA
| | - Erin S Baker
- Department of Chemistry, University of North Carolina Chapel Hill NC 27514 USA
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University College Station TX 77843 USA
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12
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Herrera-Pérez S, Lamas JA. TREK channels in Mechanotransduction: a Focus on the Cardiovascular System. Front Cardiovasc Med 2023; 10:1180242. [PMID: 37288256 PMCID: PMC10242076 DOI: 10.3389/fcvm.2023.1180242] [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: 03/06/2023] [Accepted: 04/26/2023] [Indexed: 06/09/2023] Open
Abstract
Mechano-electric feedback is one of the most important subsystems operating in the cardiovascular system, but the underlying molecular mechanism remains rather unknown. Several proteins have been proposed to explain the molecular mechanism of mechano-transduction. Transient receptor potential (TRP) and Piezo channels appear to be the most important candidates to constitute the molecular mechanism behind of the inward current in response to a mechanical stimulus. However, the inhibitory/regulatory processes involving potassium channels that operate on the cardiac system are less well known. TWIK-Related potassium (TREK) channels have emerged as strong candidates due to their capacity for the regulation of the flow of potassium in response to mechanical stimuli. Current data strongly suggest that TREK channels play a role as mechano-transducers in different components of the cardiovascular system, not only at central (heart) but also at peripheral (vascular) level. In this context, this review summarizes and highlights the main existing evidence connecting this important subfamily of potassium channels with the cardiac mechano-transduction process, discussing molecular and biophysical aspects of such a connection.
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Affiliation(s)
- Salvador Herrera-Pérez
- Laboratory of Neuroscience, CINBIO, University of Vigo, Vigo, Spain
- Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), Vigo, Spain
| | - José Antonio Lamas
- Laboratory of Neuroscience, CINBIO, University of Vigo, Vigo, Spain
- Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), Vigo, Spain
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13
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Zhang Y, Fu J, Han Y, Feng D, Yue S, Zhou Y, Luo Z. Two-Pore-Domain Potassium Channel TREK-1 Mediates Pulmonary Fibrosis through Macrophage M2 Polarization and by Direct Promotion of Fibroblast Differentiation. Biomedicines 2023; 11:biomedicines11051279. [PMID: 37238950 DOI: 10.3390/biomedicines11051279] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/19/2023] [Accepted: 04/23/2023] [Indexed: 05/28/2023] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a devastating disease characterized by myofibroblast proliferation and abnormal accumulation of extracellular matrix in the lungs. After lung injury, M2 macrophages mediate the pathogenesis of pulmonary fibrosis by secreting fibrotic cytokines that promote myofibroblast activation. The TWIK-related potassium channel (TREK-1, also known as KCNK2) is a K2P channel that is highly expressed in cardiac, lung, and other tissues; it worsens various tumors, such as ovarian cancer and prostate cancer, and mediates cardiac fibrosis. However, the role of TREK-1 in lung fibrosis remains unclear. This study aimed to examine the effects of TREK-1 on bleomycin (BLM)-induced lung fibrosis. The results show that TREK-1 knockdown, mediated by the adenovirus or pharmacological inhibition of TREK-1 with fluoxetine, resulted in diminished BLM-induced lung fibrosis. TREK-1 overexpression in macrophages remarkably increased the M2 phenotype, resulting in fibroblast activation. Furthermore, TREK-1 knockdown and fluoxetine administration directly reduced the differentiation of fibroblasts to myofibroblasts by inhibiting the focal adhesion kinase (FAK)/p38 mitogen-activated protein kinases (p38)/Yes-associated protein (YAP) signaling pathway. In conclusion, TREK-1 plays a central role in the pathogenesis of BLM-induced lung fibrosis, which serves as a theoretical basis for the inhibition of TREK-1 as a potential therapy protocol for lung fibrosis.
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Affiliation(s)
- Yunna Zhang
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha 410013, China
| | - Jiafeng Fu
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha 410013, China
| | - Yang Han
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha 410013, China
| | - Dandan Feng
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha 410013, China
| | - Shaojie Yue
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha 410013, China
| | - Yan Zhou
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha 410013, China
| | - Ziqiang Luo
- Department of Physiology, Xiangya School of Medicine, Central South University, Changsha 410013, China
- Hunan Key Laboratory of Organ Fibrosis, Changsha 410013, China
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14
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Davis MJ, Earley S, Li YS, Chien S. Vascular mechanotransduction. Physiol Rev 2023; 103:1247-1421. [PMID: 36603156 PMCID: PMC9942936 DOI: 10.1152/physrev.00053.2021] [Citation(s) in RCA: 45] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 09/26/2022] [Accepted: 10/04/2022] [Indexed: 01/07/2023] Open
Abstract
This review aims to survey the current state of mechanotransduction in vascular smooth muscle cells (VSMCs) and endothelial cells (ECs), including their sensing of mechanical stimuli and transduction of mechanical signals that result in the acute functional modulation and longer-term transcriptomic and epigenetic regulation of blood vessels. The mechanosensors discussed include ion channels, plasma membrane-associated structures and receptors, and junction proteins. The mechanosignaling pathways presented include the cytoskeleton, integrins, extracellular matrix, and intracellular signaling molecules. These are followed by discussions on mechanical regulation of transcriptome and epigenetics, relevance of mechanotransduction to health and disease, and interactions between VSMCs and ECs. Throughout this review, we offer suggestions for specific topics that require further understanding. In the closing section on conclusions and perspectives, we summarize what is known and point out the need to treat the vasculature as a system, including not only VSMCs and ECs but also the extracellular matrix and other types of cells such as resident macrophages and pericytes, so that we can fully understand the physiology and pathophysiology of the blood vessel as a whole, thus enhancing the comprehension, diagnosis, treatment, and prevention of vascular diseases.
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Affiliation(s)
- Michael J Davis
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Scott Earley
- Department of Pharmacology, University of Nevada, Reno, Nevada
| | - Yi-Shuan Li
- Department of Bioengineering, University of California, San Diego, California
- Institute of Engineering in Medicine, University of California, San Diego, California
| | - Shu Chien
- Department of Bioengineering, University of California, San Diego, California
- Institute of Engineering in Medicine, University of California, San Diego, California
- Department of Medicine, University of California, San Diego, California
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15
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Kim SE, Yin MZ, Roh JW, Kim HJ, Choi SW, Wainger BJ, Kim WK, Kim SJ, Nam JH. Multi-target modulation of ion channels underlying the analgesic effects of α-mangostin in dorsal root ganglion neurons. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 115:154791. [PMID: 37094425 DOI: 10.1016/j.phymed.2023.154791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 03/15/2023] [Accepted: 03/28/2023] [Indexed: 05/03/2023]
Abstract
BACKGROUND α-Mangostin is a xanthone isolated from the pericarps of mangosteen fruit with, and has analgesic properties. Although the effects suggest an interaction of α-mangostin with ion channels in the nociceptive neurons, electrophysiological investigation of the underlying mechanism has not been performed. HYPOTHESIS We hypothesized that α-Mangostin exerts its analgesic effects by modulating the activity of various ion channels in dorsal root ganglion (DRG) neurons. METHODS We performed a whole-cell patch clamp study using mouse DRG neurons, HEK293T cells overexpressing targeted ion channels, and ND7/23 cells. Molecular docking (MD) and in silico absorption, distribution, metabolism, and excretion (ADME) analyses were conducted to obtain further insights into the binding sites and pharmacokinetics, respectively. RESULTS Application of α-mangostin (1-3 µM) hyperpolarized the resting membrane potential (RMP) of small-sized DRG neurons by increasing background K+ conductance and thereby inhibited action potential generation. At micromolar levels, α-mangostin activates TREK-1, TREK-2, or TRAAK, members of the two-pore domain K+ channel (K2P) family known to be involved in RMP formation in DRG neurons. Furthermore, capsaicin-induced TRPV1 currents were potently inhibited by α-mangostin (0.43 ± 0.27 µM), and partly suppressed tetrodotoxin-sensitive voltage-gated Na+ channel (NaV) currents. MD simulation revealed that multiple oxygen atoms in α-mangostin may form stable hydrogen bonds with TREKs, TRAAK, TRPV1, and NaV channels. In silico ADME tests suggested that α-mangostin may satisfy the drug-likeness properties without penetrating the blood-brain barrier. CONCLUSION The analgesic properties of α-mangostin might be mediated by the multi-target modulation of ion channels, including TREK/TRAAK activation, TRPV1 inhibition, and reduction of the tetrodotoxin-sensitive NaV current. The findings suggest that the phytochemical can be a multi-ion channel-targeting drug and an alternative drug for effective pain management.
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Affiliation(s)
- Sung Eun Kim
- Department of Physiology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 03080, Republic of Korea
| | - Ming Zhe Yin
- Department of Anesthesiology, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Jae Won Roh
- Department of Pharmacology, Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Hyun Jong Kim
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Republic of Korea; Channelopathy Research Center (CRC), Dongguk University College of Medicine, Gyeonggi-do 10326, Republic of Korea
| | - Seong Woo Choi
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Republic of Korea
| | - Brian J Wainger
- Departments Anesthesia, Critical Care & Pain Medicine and Neurology, Massachusetts General Hospital, Harvard Medical School, Boston 02114, ts, USA
| | - Woo Kyung Kim
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, Gyeonggi-do 10326, Republic of Korea; Department of Internal Medicine Graduate School of Medicine, Dongguk University, Gyeonggi-do 10326, Republic of Korea.
| | - Sung Joon Kim
- Department of Physiology, Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 03080, Republic of Korea.
| | - Joo Hyun Nam
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Republic of Korea; Departments Anesthesia, Critical Care & Pain Medicine and Neurology, Massachusetts General Hospital, Harvard Medical School, Boston 02114, ts, USA; Channelopathy Research Center (CRC), Dongguk University College of Medicine, Gyeonggi-do 10326, Republic of Korea.
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16
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Goodman MB, Haswell ES, Vásquez V. Mechanosensitive membrane proteins: Usual and unusual suspects in mediating mechanotransduction. J Gen Physiol 2023; 155:e202213248. [PMID: 36696153 PMCID: PMC9930137 DOI: 10.1085/jgp.202213248] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
This Viewpoint, which accompanies a Special Issue focusing on membrane mechanosensors, discusses unifying and unique features of both established and emerging mechanosensitive (MS) membrane proteins, their distribution across protein families and phyla, and current and future challenges in the study of these important proteins and their partners. MS membrane proteins are essential for tissue development, cellular motion, osmotic homeostasis, and sensing external and self-generated mechanical cues like those responsible for touch and proprioception. Though researchers' attention and this Viewpoint focus on a few famous ion channels that are considered the usual suspects as MS mechanosensors, we also discuss some of the more unusual suspects, such as G-protein coupled receptors. As the field continues to grow, so too will the list of proteins suspected to function as mechanosensors and the diversity of known MS membrane proteins.
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Affiliation(s)
- Miriam B. Goodman
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - Elizabeth S. Haswell
- Department of Biology, Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Valeria Vásquez
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
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17
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Xing C, Bao L, Li W, Fan H. Progress on role of ion channels of cardiac fibroblasts in fibrosis. Front Physiol 2023; 14:1138306. [PMID: 36969589 PMCID: PMC10033868 DOI: 10.3389/fphys.2023.1138306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/27/2023] [Indexed: 03/29/2023] Open
Abstract
Cardiac fibrosis is defined as excessive deposition of extracellular matrix (ECM) in pathological conditions. Cardiac fibroblasts (CFs) activated by injury or inflammation differentiate into myofibroblasts (MFs) with secretory and contractile functions. In the fibrotic heart, MFs produce ECM which is composed mainly of collagen and is initially involved in maintaining tissue integrity. However, persistent fibrosis disrupts the coordination of excitatory contractile coupling, leading to systolic and diastolic dysfunction, and ultimately heart failure. Numerous studies have demonstrated that both voltage- and non-voltage-gated ion channels alter intracellular ion levels and cellular activity, contributing to myofibroblast proliferation, contraction, and secretory function. However, an effective treatment strategy for myocardial fibrosis has not been established. Therefore, this review describes the progress made in research related to transient receptor potential (TRP) channels, Piezo1, Ca2+ release-activated Ca2+ (CRAC) channels, voltage-gated Ca2+ channels (VGCCs), sodium channels, and potassium channels in myocardial fibroblasts with the aim of providing new ideas for treating myocardial fibrosis.
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18
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Zhu Y, Schrecke S, Tang S, Odenkirk MT, Walker T, Stover L, Lyu J, Zhang T, Russell D, Baker ES, Yan X, Laganowsky A. Cupric Ions Selectively Modulate TRAAK-Phosphatidylserine Interactions. J Am Chem Soc 2022; 144:7048-7053. [PMID: 35421309 DOI: 10.1021/jacs.2c00612] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
TRAAK and TREK2 are two-pore domain K+ (K2P) channels and are modulated by diverse factors including temperature, membrane stretching, and lipids, such as phosphatidic acid. In addition, copper and zinc, both of which are essential for life, are known to regulate TREK2 and a number of other ion channels. However, the role of ions in the association of lipids with integral membrane proteins is poorly understood. Here, we discover cupric ions selectively modulate the binding of phosphatidylserine (PS) to TRAAK but not TREK2. Other divalent cations (Ca2+, Mg2+, and Zn2+) bind both channels but have no impact on binding PS and other lipids. Additionally, TRAAK binds more avidly to Cu2+ and Zn2+ than TREK2. In the presence of Cu2+, TRAAK binds similarly to PS with different acyl chains, indicating a crucial role of the serine headgroup in coordinating Cu2+. High-resolution native mass spectrometry (MS) enables the determination of equilibrium binding constants for distinct Cu2+-bound stoichiometries and uncovered the highest coupling factor corresponds to a 1:1 PS-to-Cu2+ ratio. Interestingly, the next three highest coupling factors had a ∼1.5:1 PS-to-Cu2+ ratio. Our findings bring forth the role of cupric ions as an essential cofactor in selective TRAAK-PS interactions.
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Affiliation(s)
- Yun Zhu
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Samantha Schrecke
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Shuli Tang
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Melanie T Odenkirk
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Thomas Walker
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Lauren Stover
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Jixing Lyu
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Tianqi Zhang
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - David Russell
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Erin S Baker
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States.,Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Xin Yan
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Arthur Laganowsky
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
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19
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Miles L, Powell J, Kozak C, Song Y. Mechanosensitive Ion Channels, Axonal Growth, and Regeneration. Neuroscientist 2022:10738584221088575. [PMID: 35414308 PMCID: PMC9556659 DOI: 10.1177/10738584221088575] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cells sense and respond to mechanical stimuli by converting those stimuli into biological signals, a process known as mechanotransduction. Mechanotransduction is essential in diverse cellular functions, including tissue development, touch sensitivity, pain, and neuronal pathfinding. In the search for key players of mechanotransduction, several families of ion channels were identified as being mechanosensitive and were demonstrated to be activated directly by mechanical forces in both the membrane bilayer and the cytoskeleton. More recently, Piezo ion channels were discovered as a bona fide mechanosensitive ion channel, and its characterization led to a cascade of research that revealed the diverse functions of Piezo proteins and, in particular, their involvement in neuronal repair.
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Affiliation(s)
- Leann Miles
- The Graduate Group in Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA, USA
| | - Jackson Powell
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Casey Kozak
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Yuanquan Song
- The Graduate Group in Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA, USA.,Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
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20
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Pope L, Minor DL. The Polysite Pharmacology of TREK K 2P Channels. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1349:51-65. [PMID: 35138610 DOI: 10.1007/978-981-16-4254-8_4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
K2P (KCNK) potassium channels form "background" or "leak" currents that have critical roles in cell excitability control in the brain, cardiovascular system, and somatosensory neurons. Similar to many ion channel families, studies of K2Ps have been limited by poor pharmacology. Of six K2P subfamilies, the thermo- and mechanosensitive TREK subfamily comprising K2P2.1 (TREK-1), K2P4.1 (TRAAK), and K2P10.1 (TREK-2) are the first to have structures determined for each subfamily member. These structural studies have revealed key architectural features that underlie K2P function and have uncovered sites residing at every level of the channel structure with respect to the membrane where small molecules or lipids can control channel function. This polysite pharmacology within a relatively small (~70 kDa) ion channel comprises four structurally defined modulator binding sites that occur above (Keystone inhibitor site), at the level of (K2P modulator pocket), and below (Fenestration and Modulatory lipid sites) the C-type selectivity filter gate that is at the heart of K2P function. Uncovering this rich structural landscape provides the framework for understanding and developing subtype-selective modulators to probe K2P function that may provide leads for drugs for anesthesia, pain, arrhythmia, ischemia, and migraine.
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Affiliation(s)
- Lianne Pope
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, US
| | - Daniel L Minor
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, US. .,Departments of Biochemistry and Biophysics, and Cellular and Molecular Pharmacology, University of California, San Francisco, CA, USA. .,California Institute for Quantitative Biomedical Research, University of California, San Francisco, CA, USA. .,Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, CA, USA. .,Molecular Biophysics and Integrated Bio-imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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21
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McCoull D, Veale EL, Walsh Y, Byrom L, Avkiran T, Large JM, Vaitone E, Gaffey F, Jerman J, Mathie A, Wright PD. Aprepitant is a novel, selective activator of the K2P channel TRAAK. Biochem Biophys Res Commun 2021; 588:41-46. [PMID: 34942533 DOI: 10.1016/j.bbrc.2021.12.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 12/12/2021] [Indexed: 11/02/2022]
Abstract
TRAAK (KCNK4, K2P4.1) is a mechanosensitive two-pore domain potassium (K2P) channel. Due to its expression within sensory neurons and genetic link to neuropathic pain it represents a promising potential target for novel analgesics. In common with many other channels in the wider K2P sub-family, there remains a paucity of small molecule pharmacological tools. Specifically, there is a lack of molecules selective for TRAAK over the other members of the TREK subfamily of K2P channels. We developed a thallium flux assay to allow high throughput screening of compounds and facilitate the identification of novel TRAAK activators. Using a library of ∼1200 drug like molecules we identified Aprepitant as a small molecule activator of TRAAK. Aprepitant is an NK-1 antagonist used to treat nausea and vomiting. Close structural analogues of Aprepitant and a range of NK-1 antagonists were also selected or designed for purchase or brief chemical synthesis and screened for their ability to activate TRAAK. Electrophysiology experiments confirmed that Aprepitant activates both the 'long' and 'short' transcript variants of TRAAK. We also demonstrated that Aprepitant is selective and does not activate other members of the K2P superfamily. This work describes the development of a high throughput assay to identify potential TRAAK activators and subsequent identification and confirmation of the novel TRAAK activator Aprepitant. This discovery identifies a useful tool compound which can be used to further probe the function of TRAAK K2P channels.
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Affiliation(s)
- D McCoull
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK.
| | - E L Veale
- Medway School of Pharmacy, University of Greenwich and University of Kent, Anson Building, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
| | - Y Walsh
- Medway School of Pharmacy, University of Greenwich and University of Kent, Anson Building, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK
| | - L Byrom
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - T Avkiran
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - J M Large
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - E Vaitone
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - F Gaffey
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - J Jerman
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
| | - A Mathie
- Medway School of Pharmacy, University of Greenwich and University of Kent, Anson Building, Central Avenue, Chatham Maritime, Kent, ME4 4TB, UK; School of Engineering, Arts, Science and Technology, University of Suffolk, Ipswich, IP4 1QJ, UK
| | - P D Wright
- LifeArc, Accelerator Building, Open Innovation Campus, Stevenage, SG1 2FX, UK
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22
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Lewis KJ. Osteocyte calcium signaling - A potential translator of mechanical load to mechanobiology. Bone 2021; 153:116136. [PMID: 34339908 DOI: 10.1016/j.bone.2021.116136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 06/25/2021] [Accepted: 07/27/2021] [Indexed: 10/20/2022]
Abstract
Osteocytes are embedded dendritic bone cells; by virtue of their position in bone tissue, ability to coordinate bone building osteoblasts and resorbing osteoclasts, and sensitivity to tissue level mechanical loading, they serve as the resident bone mechanosensor. The mechanisms osteocytes use to change mechanical loading into biological signals that drive tissue level changes has been well studied over the last 30 years, however the ways loading parameters are encoded at the cellular level are still not fully understood. Calcium signaling is a first messenger signal exhibited by osteocytes in response to mechanical forces. A body of work interrogating the mechanisms of osteocyte calcium signaling exists and is presently expanding, presenting the opportunity to better understand the relationship between calcium signaling characteristics and tuned osteocyte responses to tissue level strain features (e.g. magnitude, duration, frequency). This review covers the history of osteocyte load induced calcium signaling and highlights potential cellular mechanisms used by osteocytes to turn details about loading parameters into biological events.
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Affiliation(s)
- Karl J Lewis
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States of America.
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23
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Two-Pore-Domain Potassium (K 2P-) Channels: Cardiac Expression Patterns and Disease-Specific Remodelling Processes. Cells 2021; 10:cells10112914. [PMID: 34831137 PMCID: PMC8616229 DOI: 10.3390/cells10112914] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/18/2021] [Accepted: 10/22/2021] [Indexed: 12/23/2022] Open
Abstract
Two-pore-domain potassium (K2P-) channels conduct outward K+ currents that maintain the resting membrane potential and modulate action potential repolarization. Members of the K2P channel family are widely expressed among different human cell types and organs where they were shown to regulate important physiological processes. Their functional activity is controlled by a broad variety of different stimuli, like pH level, temperature, and mechanical stress but also by the presence of lipids or pharmacological agents. In patients suffering from cardiovascular diseases, alterations in K2P-channel expression and function have been observed, suggesting functional significance and a potential therapeutic role of these ion channels. For example, upregulation of atrial specific K2P3.1 (TASK-1) currents in atrial fibrillation (AF) patients was shown to contribute to atrial action potential duration shortening, a key feature of AF-associated atrial electrical remodelling. Therefore, targeting K2P3.1 (TASK-1) channels might constitute an intriguing strategy for AF treatment. Further, mechanoactive K2P2.1 (TREK-1) currents have been implicated in the development of cardiac hypertrophy, cardiac fibrosis and heart failure. Cardiovascular expression of other K2P channels has been described, functional evidence in cardiac tissue however remains sparse. In the present review, expression, function, and regulation of cardiovascular K2P channels are summarized and compared among different species. Remodelling patterns, observed in disease models are discussed and compared to findings from clinical patients to assess the therapeutic potential of K2P channels.
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24
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Rueda-Ruzafa L, Herrera-Pérez S, Campos-Ríos A, Lamas JA. Are TREK Channels Temperature Sensors? Front Cell Neurosci 2021; 15:744702. [PMID: 34690704 PMCID: PMC8526543 DOI: 10.3389/fncel.2021.744702] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 09/08/2021] [Indexed: 11/17/2022] Open
Abstract
Internal human body normal temperature fluctuates between 36.5 and 37.5°C and it is generally measured in the oral cavity. Interestingly, most electrophysiological studies on the functioning of ion channels and their role in neuronal behavior are carried out at room temperature, which usually oscillates between 22 and 24°C, even when thermosensitive channels are studied. We very often forget that if the core of the body reached that temperature, the probability of death from cardiorespiratory arrest would be extremely high. Does this mean that we are studying ion channels in dying neurons? Thousands of electrophysiological experiments carried out at these low temperatures suggest that most neurons tolerate this aggression quite well, at least for the duration of the experiments. This also seems to happen with ion channels, although studies at different temperatures indicate large changes in both, neuron and channel behavior. It is known that many chemical, physical and therefore physiological processes, depend to a great extent on body temperature. Temperature clearly affects the kinetics of numerous events such as chemical reactions or conformational changes in proteins but, what if these proteins constitute ion channels and these channels are specifically designed to detect changes in temperature? In this review, we discuss the importance of the potassium channels of the TREK subfamily, belonging to the recently discovered family of two-pore domain channels, in the transduction of thermal sensitivity in different cell types.
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Affiliation(s)
- Lola Rueda-Ruzafa
- CINBIO, Laboratory of Neuroscience, University of Vigo, Vigo, Spain.,Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), Vigo, Spain
| | - Salvador Herrera-Pérez
- CINBIO, Laboratory of Neuroscience, University of Vigo, Vigo, Spain.,Grupo de Neurofisiología Experimental y Circuitos Neuronales, Hospital Nacional de Parapléjicos, SESCAM, Toledo, Spain
| | - Ana Campos-Ríos
- CINBIO, Laboratory of Neuroscience, University of Vigo, Vigo, Spain.,Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), Vigo, Spain
| | - J A Lamas
- CINBIO, Laboratory of Neuroscience, University of Vigo, Vigo, Spain.,Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), Vigo, Spain
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25
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Uchida Y, Izumizaki M. Effect of menstrual cycle and female hormones on TRP and TREK channels in modifying thermosensitivity and physiological functions in women. J Therm Biol 2021; 100:103029. [PMID: 34503776 DOI: 10.1016/j.jtherbio.2021.103029] [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] [Received: 01/05/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 12/15/2022]
Abstract
Thermoregulation is crucial for human survival at various ambient temperatures. Transient receptor potential (TRP) and TWIK-related K+ (TREK) channels expressed in sensory neurons play a role in peripheral thermosensitivity for temperature detection. In addition, these channels have various physiological roles in the skeletal, nervous, immune, vascular, digestive, and urinary systems. In women, the female hormones estradiol (E2) and progesterone (P4), which fluctuate during the menstrual cycle, affect various physiological functions, such as thermoregulation in hot and cold environments. The present review describes the effect of female hormones on TRP and TREK channels and related physiological functions. The P4 decreased thermosensitivity via TRPV1. E2 facilitates temporomandibular joint disease (TRPV1), breast cancer (TRPM8), and calcium absorption in the digestive system (TRPV5 and TRPV6), inhibits the facilitation of vasoconstriction (TRPM3), nerve inflammation (TRPM4), sweetness sensitivity (TRPM5), and menstrual disorders (TRPC1), and prevents insulin resistance (TRPC5) via each channel. P4 inhibits vasoconstriction (TRPM3), sweetness sensitivity (TRPM5), ciliary motility in the lungs (TRPV4), menstrual disorder (TRPC1), and immunity (TRPC3), and facilitates breast cancer (TRPV6) via each channel as indicated. The effects of female hormones on TREK channels and physiological functions are still under investigation. In summary, female hormones influence physiological functions via some TRP channels; however, the literature is not comprehensive and future studies are needed, especially those related to thermoregulation in women.
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Affiliation(s)
- Yuki Uchida
- Department of Physiology, Showa University School of Medicine, Tokyo, Japan.
| | - Masahiko Izumizaki
- Department of Physiology, Showa University School of Medicine, Tokyo, Japan
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26
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Roy Choudhury A, Großhans J, Kong D. Ion Channels in Epithelial Dynamics and Morphogenesis. Cells 2021; 10:cells10092280. [PMID: 34571929 PMCID: PMC8465836 DOI: 10.3390/cells10092280] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/22/2021] [Accepted: 08/30/2021] [Indexed: 01/21/2023] Open
Abstract
Mechanosensitive ion channels mediate the neuronal sensation of mechanical signals such as sound, touch, and pain. Recent studies point to a function of these channel proteins in cell types and tissues in addition to the nervous system, such as epithelia, where they have been little studied, and their role has remained elusive. Dynamic epithelia are intrinsically exposed to mechanical forces. A response to pull and push is assumed to constitute an essential part of morphogenetic movements of epithelial tissues, for example. Mechano-gated channels may participate in sensing and responding to such forces. In this review, focusing on Drosophila, we highlight recent results that will guide further investigations concerned with the mechanistic role of these ion channels in epithelial cells.
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27
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Schwarz JR. Function of K2P channels in the mammalian node of Ranvier. J Physiol 2021; 599:4427-4439. [PMID: 34425634 DOI: 10.1113/jp281723] [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] [Received: 06/15/2021] [Accepted: 08/09/2021] [Indexed: 11/08/2022] Open
Abstract
In myelinated nerve fibres, action potentials are generated at nodes of Ranvier. These structures are located at interruptions of the myelin sheath, forming narrow gaps with small rings of axolemma freely exposed to the extracellular space. The mammalian node contains a high density of Na+ channels and K+ -selective leakage channels. Voltage-dependent Kv1 channels are only present in the juxta-paranode. Recently, the leakage channels have been identified as K2P channels (TRAAK, TREK-1). K2P channels are K+ -selective 'background' channels, characterized by outward rectification and their ability to be activated, e.g. by temperature, mechanical stretch or arachidonic acid. We are only beginning to elucidate the peculiar functions of nodal K2P channels. I will discuss two functions of the nodal K2P-mediated conductance. First, at body temperature K2P channels have a high open probability, thereby inducing a resting potential of about -85 mV. This negative resting potential reduces steady-state Na+ channel inactivation and ensures a large Na+ inward current upon a depolarizing stimulus. Second, the K2P conductance is involved in nodal action potential repolarization. The identification of nodal K2P channels is exciting since it shows that the nodal K+ conductance is not a fixed value but can be changed: it can be increased or decreased by a broad range of K2P modulators, thereby modulating, for example, the resting potential. The functional importance of nodal K2P channels will be exemplified by describing in more detail the function of the K2P conductance increase by raising the temperature from room temperature to 37°C.
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Affiliation(s)
- Jürgen R Schwarz
- Institute of Molecular Neurogenetics, Center for Molecular Neurobiology Hamburg (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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28
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Lengyel M, Enyedi P, Czirják G. Negative Influence by the Force: Mechanically Induced Hyperpolarization via K 2P Background Potassium Channels. Int J Mol Sci 2021; 22:ijms22169062. [PMID: 34445768 PMCID: PMC8396510 DOI: 10.3390/ijms22169062] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 02/08/2023] Open
Abstract
The two-pore domain K2P subunits form background (leak) potassium channels, which are characterized by constitutive, although not necessarily constant activity, at all membrane potential values. Among the fifteen pore-forming K2P subunits encoded by the KCNK genes, the three members of the TREK subfamily, TREK-1, TREK-2, and TRAAK are mechanosensitive ion channels. Mechanically induced opening of these channels generally results in outward K+ current under physiological conditions, with consequent hyperpolarization and inhibition of membrane potential-dependent cellular functions. In the past decade, great advances have been made in the investigation of the molecular determinants of mechanosensation, and members of the TREK subfamily have emerged among the best-understood examples of mammalian ion channels directly influenced by the tension of the phospholipid bilayer. In parallel, the crucial contribution of mechano-gated TREK channels to the regulation of membrane potential in several cell types has been reported. In this review, we summarize the general principles underlying the mechanical activation of K2P channels, and focus on the physiological roles of mechanically induced hyperpolarization.
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29
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Singh S, Agarwal P, Ravichandiran V. Two-Pore Domain Potassium Channel in Neurological Disorders. J Membr Biol 2021; 254:367-380. [PMID: 34169340 DOI: 10.1007/s00232-021-00189-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/26/2021] [Indexed: 01/10/2023]
Abstract
K2P channel is the leaky potassium channel that is critical to keep up the negative resting membrane potential for legitimate electrical conductivity of the excitable tissues. Recently, many substances and medication elements are discovered that could either straightforwardly or in a roundabout way influence the 15 distinctive K+ ion channels including TWIK, TREK, TASK, TALK, THIK, and TRESK. Opening and shutting of these channels or any adjustment in their conduct is thought to alter the pathophysiological condition of CNS. There is no document available till now to explain in detail about the molecular mechanism of agents acting on K2P channel. Accordingly, in this review we cover the current research and mechanism of action of these channels, we have also tried to mention the detailed effect of drugs and how the channel behavior changes by focusing on recent advances regarding activation and modulation of ion channels.
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Affiliation(s)
- Sanjiv Singh
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Export Promotions Industrial Park (EPIP), Industrial Area, Hajipur, District, Vaishali, 844102, Bihar, India.
| | - Punita Agarwal
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Export Promotions Industrial Park (EPIP), Industrial Area, Hajipur, District, Vaishali, 844102, Bihar, India
| | - V Ravichandiran
- Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research (NIPER), Export Promotions Industrial Park (EPIP), Industrial Area, Hajipur, District, Vaishali, 844102, Bihar, India
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30
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Herrera-Pérez S, Campos-Ríos A, Rueda-Ruzafa L, Lamas JA. Contribution of K2P Potassium Channels to Cardiac Physiology and Pathophysiology. Int J Mol Sci 2021; 22:ijms22126635. [PMID: 34205717 PMCID: PMC8234311 DOI: 10.3390/ijms22126635] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/08/2021] [Accepted: 06/18/2021] [Indexed: 12/28/2022] Open
Abstract
Years before the first two-pore domain potassium channel (K2P) was cloned, certain ion channels had already been demonstrated to be present in the heart with characteristics and properties usually attributed to the TREK channels (a subfamily of K2P channels). K2P channels were later detected in cardiac tissue by RT-PCR, although the distribution of the different K2P subfamilies in the heart seems to depend on the species analyzed. In order to collect relevant information in this regard, we focus here on the TWIK, TASK and TREK cardiac channels, their putative roles in cardiac physiology and their implication in coronary pathologies. Most of the RNA expression data and electrophysiological recordings available to date support the presence of these different K2P subfamilies in distinct cardiac cells. Likewise, we show how these channels may be involved in certain pathologies, such as atrial fibrillation, long QT syndrome and Brugada syndrome.
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31
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Pang JJ, Gao F, Wu SM. Generators of Pressure-Evoked Currents in Vertebrate Outer Retinal Neurons. Cells 2021; 10:cells10061288. [PMID: 34067375 PMCID: PMC8224636 DOI: 10.3390/cells10061288] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/13/2021] [Accepted: 05/19/2021] [Indexed: 12/19/2022] Open
Abstract
(1) Background: High-tension glaucoma damages the peripheral vision dominated by rods. How mechanosensitive channels (MSCs) in the outer retina mediate pressure responses is unclear. (2) Methods: Immunocytochemistry, patch clamp, and channel fluorescence were used to study MSCs in salamander photoreceptors. (3) Results: Immunoreactivity of transient receptor potential channel vanilloid 4 (TRPV4) was revealed in the outer plexiform layer, K+ channel TRAAK in the photoreceptor outer segment (OS), and TRPV2 in some rod OS disks. Pressure on the rod inner segment evoked sustained currents of three components: (A) the inward current at <-50 mV (Ipi), sensitive to Co2+; (B) leak outward current at ≥-80 mV (Ipo), sensitive to intracellular Cs+ and ruthenium red; and (C) cation current reversed at ~10 mV (Ipc). Hypotonicity induced slow currents like Ipc. Environmental pressure and light increased the FM 1-43-identified open MSCs in the OS membrane, while pressure on the OS with internal Cs+ closed a Ca2+-dependent current reversed at ~0 mV. Rod photocurrents were thermosensitive and affected by MSC blockers. (4) Conclusions: Rods possess depolarizing (TRPV) and hyperpolarizing (K+) MSCs, which mediate mutually compensating currents between -50 mV and 10 mV, serve as an electrical cushion to minimize the impact of ocular mechanical stress.
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32
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Brouns I, Verckist L, Pintelon I, Timmermans JP, Adriaensen D. Pulmonary Sensory Receptors. ADVANCES IN ANATOMY EMBRYOLOGY AND CELL BIOLOGY 2021; 233:1-65. [PMID: 33950466 DOI: 10.1007/978-3-030-65817-5_1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Inge Brouns
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium.
| | - Line Verckist
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium
| | - Isabel Pintelon
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium
| | - Jean-Pierre Timmermans
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium
| | - Dirk Adriaensen
- Laboratory of Cell Biology and Histology, Department of Veterinary Sciences, University of Antwerp, Antwerpen (Wilrijk), Belgium
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33
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Natale AM, Deal PE, Minor DL. Structural Insights into the Mechanisms and Pharmacology of K 2P Potassium Channels. J Mol Biol 2021; 433:166995. [PMID: 33887333 PMCID: PMC8436263 DOI: 10.1016/j.jmb.2021.166995] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/08/2021] [Accepted: 04/09/2021] [Indexed: 01/10/2023]
Abstract
Leak currents, defined as voltage and time independent flows of ions across cell membranes, are central to cellular electrical excitability control. The K2P (KCNK) potassium channel class comprises an ion channel family that produces potassium leak currents that oppose excitation and stabilize the resting membrane potential in cells in the brain, cardiovascular system, immune system, and sensory organs. Due to their widespread tissue distribution, K2Ps contribute to many physiological and pathophysiological processes including anesthesia, pain, arrythmias, ischemia, hypertension, migraine, intraocular pressure regulation, and lung injury responses. Structural studies of six homomeric K2Ps have established the basic architecture of this channel family, revealed key moving parts involved in K2P function, uncovered the importance of asymmetric pinching and dilation motions in the K2P selectivity filter (SF) C-type gate, and defined two K2P structural classes based on the absence or presence of an intracellular gate. Further, a series of structures characterizing K2P:modulator interactions have revealed a striking polysite pharmacology housed within a relatively modestly sized (~70 kDa) channel. Binding sites for small molecules or lipids that control channel function are found at every layer of the channel structure, starting from its extracellular side through the portion that interacts with the membrane bilayer inner leaflet. This framework provides the basis for understanding how gating cues sensed by different channel parts control function and how small molecules and lipids modulate K2P activity. Such knowledge should catalyze development of new K2P modulators to probe function and treat a wide range of disorders.
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Affiliation(s)
- Andrew M Natale
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA
| | - Parker E Deal
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA
| | - Daniel L Minor
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA; Departments of Biochemistry and Biophysics, and Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, University of California, San Francisco, CA 94158, USA; Kavli Institute for Fundamental Neuroscience University of California, San Francisco, CA 94158, USA; Molecular Biophysics and Integrated Bio-imaging Division Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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34
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Long-term dietary supplementation with plant-derived omega-3 fatty acid improves outcome in experimental ischemic stroke. Atherosclerosis 2021; 325:89-98. [PMID: 33915355 DOI: 10.1016/j.atherosclerosis.2021.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 03/26/2021] [Accepted: 04/13/2021] [Indexed: 02/08/2023]
Abstract
BACKGROUND AND AIMS Early revascularization -the gold standard therapy for ischemic stroke- is often withheld in the elderly population due to high risk of complications. Thus, safe and effective preventive and therapeutic options are needed. The plant-derived omega-3-fatty-acid alpha-linolenic-acid (ALA) has emerged as a novel cardiovascular-protective agent. As of yet, little is known about its potential therapeutic effects on stroke. We hereby aimed to investigate the impact of a clinically relevant long-term dietary intervention with ALA on stroke outcome. METHODS Six month-old C57BL/6 wildtype males were either fed an ALA-rich (high ALA) or a control diet (low ALA) for 12 months. At 18 months, brain ischemia/reperfusion was induced by transient middle cerebral artery occlusion (tMCAO). Stroke size and neurological function were assessed. Functional blood-brain-barrier-(BBB) permeability and protein expression were assessed by immunohistochemistry. Baseline inflammatory markers were measured at 18 months. RESULTS High ALA-fed animals displayed decreased circulating TNF-α levels and Neutrophil-to-Lymphocyte Ratios at 18 months. Stroke size and neurological dysfunction were significantly reduced in high ALA-fed animals. Coherently to the reduced stroke size, functional BBB integrity and occludin endothelial expression were maintained by high ALA supplementation. Additionally, ALA reduced endothelial activation and thus recruitment and activation of macrophages and resident microglia. Finally, high ALA diet reduced the expression of BBB-degrading and neurotoxic MMP-3 and MMP-9. CONCLUSIONS We demonstrate the beneficial effects of a clinically relevant and feasible dietary intervention with a safe and readily available compound in the setting of stroke. The protective effects observed with ALA supplementation may relate to blunting of inflammation and might pave the way for novel stroke treatments.
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35
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Huang L, Xu G, Jiang R, Luo Y, Zuo Y, Liu J. Development of Non-opioid Analgesics Targeting Two-pore Domain Potassium Channels. Curr Neuropharmacol 2021; 20:16-26. [PMID: 33827408 PMCID: PMC9199554 DOI: 10.2174/1570159x19666210407152528] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/14/2021] [Accepted: 03/24/2021] [Indexed: 02/08/2023] Open
Abstract
Two-pore domain potassium (K2P) channels are a diverse family of potassium channels. K2P channels generate background leak potassium currents to regulate cellular excitability and are thereby involved in a wide range of neurological disorders. K2P channels are modulated by a variety of physicochemical factors such as mechanical stretch, temperature, and pH. In the the peripheral nervous system (PNS), K2P channels are widely expressed in nociceptive neurons and play a critical roles in pain perception. In this review, we summarize the recent advances in the pharmacological properties of K2P channels, with a focus on the exogenous small-molecule activators targeting K2P channels. We emphasize the subtype-selectivity, cellular and in vivo pharmacological properties of all the reported small-molecule activators. The key underlying analgesic mechanisms mediated by K2P are also summarized based on the data in the literature from studies using small-molecule activators and genetic knock-out animals. We discuss advantages and limitations of the translational perspectives of K2P in pain medicine and provide outstanding questions for future studies in the end.
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Affiliation(s)
- Lu Huang
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
| | - Guangyin Xu
- Department of Physiology and Neurobiology, Institute of Neuroscience, Medical College of Soochow University, Suzhou, 215123, Jiangsu. China
| | - Ruotian Jiang
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
| | - Yuncheng Luo
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
| | - Yunxia Zuo
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
| | - Jin Liu
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610000, Sichuan. China
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Momin A, Bahrampour S, Min HK, Chen X, Wang X, Sun Y, Huang X. Channeling Force in the Brain: Mechanosensitive Ion Channels Choreograph Mechanics and Malignancies. Trends Pharmacol Sci 2021; 42:367-384. [PMID: 33752907 DOI: 10.1016/j.tips.2021.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 02/15/2021] [Accepted: 02/26/2021] [Indexed: 12/15/2022]
Abstract
Force is everywhere. Through cell-intrinsic activities and interactions with the microenvironment, cells generate, transmit, and sense mechanical forces, such as compression, tension, and shear stress. These forces shape the mechanical properties of cells and tissues. Akin to how balanced biochemical signaling safeguards physiological processes, a mechanical optimum is required for homeostasis. The brain constructs a mechanical optimum from its cellular and extracellular constituents. However, in brain cancer, the mechanical properties are disrupted: tumor and nontumoral cells experience dysregulated solid and fluid stress, while tumor tissue develops altered stiffness. Mechanosensitive (MS) ion channels perceive mechanical cues to govern ion flux and cellular signaling. In this review, we describe the mechanical properties of the brain in healthy and cancer states and illustrate MS ion channels as sensors of mechanical cues to regulate malignant growth. Targeting MS ion channels offers disease insights at the interface of cancer, neuroscience, and mechanobiology to reveal therapeutic opportunities in brain tumors.
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Affiliation(s)
- Ali Momin
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ONT, M5S 3E1, Canada.
| | - Shahrzad Bahrampour
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Department of Cell and Molecular Biology (CMB), Karolinska Institutet, Stockholm, 171 77, Sweden
| | - Hyun-Kee Min
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ONT, M5S 3E1, Canada
| | - Xin Chen
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada
| | - Xian Wang
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ONT, M5S 3G8, Canada
| | - Xi Huang
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, ONT, M5G 1X8, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ONT, M5S 3E1, Canada.
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Abstract
Ultrasound modulates the electrical activity of excitable cells and offers advantages over other neuromodulatory techniques; for example, it can be noninvasively transmitted through the skull and focused to deep brain regions. However, the fundamental cellular, molecular, and mechanistic bases of ultrasonic neuromodulation are largely unknown. Here, we demonstrate ultrasound activation of the mechanosensitive K+ channel TRAAK with submillisecond kinetics to an extent comparable to canonical mechanical activation. Single-channel recordings reveal a common basis for ultrasonic and mechanical activation with stimulus-graded destabilization of long-duration closures and promotion of full conductance openings. Ultrasonic energy is transduced to TRAAK through the membrane in the absence of other cellular components, likely increasing membrane tension to promote channel opening. We further demonstrate ultrasonic modulation of neuronally expressed TRAAK. These results suggest mechanosensitive channels underlie physiological responses to ultrasound and could serve as sonogenetic actuators for acoustic neuromodulation of genetically targeted cells.
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Khoubza L, Chatelain FC, Feliciangeli S, Lesage F, Bichet D. Physiological roles of heteromerization: focus on the two-pore domain potassium channels. J Physiol 2021; 599:1041-1055. [PMID: 33347640 DOI: 10.1113/jp279870] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 12/07/2020] [Indexed: 12/28/2022] Open
Abstract
Potassium channels form the largest family of ion channels with more than 80 members involved in cell excitability and signalling. Most of them exist as homomeric channels, whereas specific conditions are required to obtain heteromeric channels. It is well established that heteromerization of voltage-gated and inward rectifier potassium channels affects their function, increasing the diversity of the native potassium currents. For potassium channels with two pore domains (K2P ), homomerization has long been considered the rule, their polymodal regulation by a wide diversity of physical and chemical stimuli being responsible for the adaptation of the leak potassium currents to cellular needs. This view has recently evolved with the accumulation of evidence of heteromerization between different K2P subunits. Several functional intragroup and intergroup heteromers have recently been identified, which contribute to the functional heterogeneity of this family. K2P heteromerization is involved in the modulation of channel expression and trafficking, promoting functional and signalling diversity. As illustrated in the Abstract Figure, heteromerization of TREK1 and TRAAK provides the cell with more possibilities of regulation. It is becoming increasingly evident that K2P heteromers contribute to important physiological functions including neuronal and cardiac excitability. Since heteromerization also affects the pharmacology of K2P channels, this understanding helps to establish K2P heteromers as new therapeutic targets for physiopathological conditions.
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Affiliation(s)
- Lamyaa Khoubza
- Université côte d'Azur, IPMC CNRS UMR7275, Laboratory of Excellence ICST, 660 route des Lucioles 06650 Valbonne, France
| | - Franck C Chatelain
- Université côte d'Azur, IPMC CNRS UMR7275, Laboratory of Excellence ICST, 660 route des Lucioles 06650 Valbonne, France
| | - Sylvain Feliciangeli
- Université côte d'Azur, IPMC CNRS UMR7275, Laboratory of Excellence ICST, 660 route des Lucioles 06650 Valbonne, France.,Inserm, 101 rue de Tolbiac, 75013, Paris, France
| | - Florian Lesage
- Université côte d'Azur, IPMC CNRS UMR7275, Laboratory of Excellence ICST, 660 route des Lucioles 06650 Valbonne, France.,Inserm, 101 rue de Tolbiac, 75013, Paris, France
| | - Delphine Bichet
- Université côte d'Azur, IPMC CNRS UMR7275, Laboratory of Excellence ICST, 660 route des Lucioles 06650 Valbonne, France
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Abstract
Two-pore domain potassium channels are formed by subunits that each contain two pore-loops moieties. Whether the channels are expressed in yeast or the human central nervous system, two subunits come together to form a single potassium selective pore. TOK1, the first two-domain channel was cloned from Saccharomyces cerevisiae in 1995 and soon thereafter, 15 distinct K2P subunits were identified in the human genome. The human K2P channels are stratified into six K2P subfamilies based on sequence as well as physiological or pharmacological similarities. Functional K2P channels pass background (or "leak") K+ currents that shape the membrane potential and excitability of cells in a broad range of tissues. In the years since they were first described, classical functional assays, latterly coupled with state-of-the-art structural and computational studies have revealed the mechanistic basis of K2P channel gating in response to specific physicochemical or pharmacological stimuli. The growing appreciation that K2P channels can play a pivotal role in the pathophysiology of a growing spectrum of diseases makes a compelling case for K2P channels as targets for drug discovery. Here, we summarize recent advances in unraveling the structure, function, and pharmacology of the K2P channels.
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Affiliation(s)
- Jordie M Kamuene
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Yu Xu
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA
| | - Leigh D Plant
- Department of Pharmaceutical Sciences, Northeastern University, Boston, MA, USA.
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Functional Exploration of the Pulmonary NEB ME. ADVANCES IN ANATOMY, EMBRYOLOGY, AND CELL BIOLOGY 2021; 233:31-67. [PMID: 33950469 DOI: 10.1007/978-3-030-65817-5_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Ocello R, Furini S, Lugli F, Recanatini M, Domene C, Masetti M. Conduction and Gating Properties of the TRAAK Channel from Molecular Dynamics Simulations with Different Force Fields. J Chem Inf Model 2020; 60:6532-6543. [PMID: 33295174 PMCID: PMC8016162 DOI: 10.1021/acs.jcim.0c01179] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Indexed: 12/20/2022]
Abstract
In recent years, the K2P family of potassium channels has been the subject of intense research activity. Owing to the complex function and regulation of this family of ion channels, it is common practice to complement experimental findings with the atomistic description provided by computational approaches such as molecular dynamics (MD) simulations, especially, in light of the unprecedented timescales accessible at present. However, despite recent substantial improvements, the accuracy of MD simulations is still undermined by the intrinsic limitations of force fields. Here, we systematically assessed the performance of the most popular force fields employed to study ion channels at timescales that are orders of magnitude greater than the ones accessible when these energy functions were first developed. Using 32 μs of trajectories, we investigated the dynamics of a member of the K2P ion channel family, the TRAAK channel, using two established force fields in simulations of biological systems: AMBER and CHARMM. We found that while results are comparable on the nanosecond timescales, significant inconsistencies arise at microsecond timescales.
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Affiliation(s)
- Riccardo Ocello
- Department
of Pharmacy and Biotechnology, Alma Mater
Studiorum−Università di Bologna, via Belmeloro 6, 40126 Bologna, Italy
| | - Simone Furini
- Department
of Medical Biotechnologies, University of
Siena, 53100 Siena, Italy
| | - Francesca Lugli
- Department
of Chemistry “G. Ciamician”, Alma Mater Studiorum—Università di Bologna, via Selmi 2, 40126 Bologna, Italy
| | - Maurizio Recanatini
- Department
of Pharmacy and Biotechnology, Alma Mater
Studiorum−Università di Bologna, via Belmeloro 6, 40126 Bologna, Italy
| | - Carmen Domene
- Department
of Chemistry, University of Bath, Claverton Down, BA2 7AY Bath, U.K.
- Department
of Chemistry, University of Oxford, Mansfield Road, OX1 3TA Oxford, U.K.
| | - Matteo Masetti
- Department
of Pharmacy and Biotechnology, Alma Mater
Studiorum−Università di Bologna, via Belmeloro 6, 40126 Bologna, Italy
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Guo W, Wang Y, Fan M, Xie S, Zhao H, Wang J, Liu Y, Xu D, Xu Y. Integrating metabolomics and network pharmacology to explore the protective effect of gross saponins of Tribulus terrestris L. fruit against ischemic stroke in rat. JOURNAL OF ETHNOPHARMACOLOGY 2020; 263:113202. [PMID: 32768639 DOI: 10.1016/j.jep.2020.113202] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 06/21/2020] [Accepted: 07/17/2020] [Indexed: 06/11/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Tribulus terrestris L. belongs to the family Zygophyllaceae and has been widely used as a folk medicine for a long history in Asian countries. Gross saponins of Tribulus terrestris L. fruit (GSTTF) has an obvious neuroprotective effect on the treatment of ischemic stroke, but its potential therapeutic mechanisms have not been thoroughly studied. AIM OF THE STUDY To investigate the protective effect of GSTTF against ischemic stroke in rat. MATERIALS AND METHODS The combination of metabolomics and network pharmacology analysis was applied to investigate the protective effects of GSTTF on ischemic stroke and its putative mechanism. The related pathway of the biomarkers highlighted from metabolomics analysis was explored, then the possible targets of GSTTF were further revealed by network pharmacology analysis. Molecular docking was conducted to investigate the interaction between the active compound and target protein. RESULTS Metabolomics analysis showed that metabolic disturbances were observed in serum for the rats in middle cerebral artery occlusion (MCAO). These MCAO-induced deviations in serum metabolism can be reversely changed by GSTTF via metabolic pathways regulation. Twenty-four proteins with the connectivity degree larger than 15 were selected by the network pharmacology analysis, which are considered as the possible therapeutic targets of the GSTTF against ischemic stroke. The results of molecular docking showed that the active compounds were capable of binding to the representative potential targets HSD11B1 and AR, respectively. And the docking mode of two compounds with the lowest binding energy to their target protein was illustrated by the ribbon binding map. CONCLUSION The present study combines metabolomics and network pharmacology analysis to investigate the mechanism of MCAO-induced ischemic stroke and reveal the efficiency and possible mechanisms of GSTTF for ischemic stroke. Further studies on the bioactive saponin as well as their synergistic action on ischemic stroke will be conducted to better reveal the underlying mechanisms.
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Affiliation(s)
- Wenjun Guo
- School of Pharmaceutical Sciences, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China; Key Laboratory of Medicinal Materials, Jilin Academy of Chinese Medicine Sciences, Changchun, Jilin, 130021, China
| | - Yang Wang
- Jilin Ginseng Academy, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China; State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Taipa, Macao, 999078, China.
| | - Meiling Fan
- Key Laboratory of Medicinal Materials, Jilin Academy of Chinese Medicine Sciences, Changchun, Jilin, 130021, China
| | - Shengxu Xie
- Key Laboratory of Medicinal Materials, Jilin Academy of Chinese Medicine Sciences, Changchun, Jilin, 130021, China
| | - Hongyu Zhao
- Key Laboratory of Medicinal Materials, Jilin Academy of Chinese Medicine Sciences, Changchun, Jilin, 130021, China
| | - Jifeng Wang
- Jilin Ginseng Academy, Changchun University of Chinese Medicine, Changchun, Jilin, 130117, China
| | - Yue Liu
- Key Laboratory of Medicinal Materials, Jilin Academy of Chinese Medicine Sciences, Changchun, Jilin, 130021, China
| | - Dongming Xu
- Key Laboratory of Medicinal Materials, Jilin Academy of Chinese Medicine Sciences, Changchun, Jilin, 130021, China
| | - Yajuan Xu
- Key Laboratory of Medicinal Materials, Jilin Academy of Chinese Medicine Sciences, Changchun, Jilin, 130021, China.
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Gürtler F, Jordan K, Tegtmeier I, Herold J, Stindl J, Warth R, Bandulik S. Cellular Pathophysiology of Mutant Voltage-Dependent Ca2+ Channel CACNA1H in Primary Aldosteronism. Endocrinology 2020; 161:5891807. [PMID: 32785697 DOI: 10.1210/endocr/bqaa135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 08/04/2020] [Indexed: 12/29/2022]
Abstract
The physiological stimulation of aldosterone production in adrenocortical glomerulosa cells by angiotensin II and high plasma K+ depends on the depolarization of the cell membrane potential and the subsequent Ca2+ influx via voltage-activated Ca2+ channels. Germline mutations of the low-voltage activated T-type Ca2+ channel CACNA1H (Cav3.2) have been found in patients with primary aldosteronism. Here, we investigated the electrophysiology and Ca2+ signaling of adrenal NCI-H295R cells overexpressing CACNA1H wildtype and mutant M1549V in order to understand how mutant CACNA1H alters adrenal cell function. Whole-cell patch-clamp measurements revealed a strong activation of mutant CACNA1H at the resting membrane potential of adrenal cells. Both the expression of wildtype and mutant CACNA1H led to a depolarized membrane potential. In addition, cells expressing mutant CACNA1H developed pronounced action potential-like membrane voltage oscillations. Ca2+ measurements showed an increased basal Ca2+ activity, an altered K+ sensitivity, and abnormal oscillating Ca2+ changes in cells with mutant CACNA1H. In addition, removal of extracellular Na+ reduced CACNA1H current, voltage oscillations, and Ca2+ levels in mutant cells, suggesting a role of the partial Na+ conductance of CACNA1H in cellular pathology. In conclusion, the pathogenesis of stimulus-independent aldosterone production in patients with CACNA1H mutations involves several factors: i) a loss of normal control of the membrane potential, ii) an increased Ca2+ influx at basal conditions, and iii) alterations in sensitivity to extracellular K+ and Na+. Finally, our findings underline the importance of CACNA1H in the control of aldosterone production and support the concept of the glomerulosa cell as an electrical oscillator.
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Affiliation(s)
- Florian Gürtler
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | - Katrin Jordan
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | - Ines Tegtmeier
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | - Janina Herold
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | - Julia Stindl
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | - Richard Warth
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
| | - Sascha Bandulik
- Medical Cell Biology, University of Regensburg, Regensburg, Germany
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Selective regulation of human TRAAK channels by biologically active phospholipids. Nat Chem Biol 2020; 17:89-95. [PMID: 32989299 PMCID: PMC7746637 DOI: 10.1038/s41589-020-00659-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/21/2020] [Indexed: 11/22/2022]
Abstract
TRAAK is an ion channel from the two-pore domain potassium (K2P) channel family with roles in maintaining the resting membrane potential and fast action potential conduction. Regulated by a wide range of physical and chemical stimuli, the affinity and selectivity of K2P4.1 towards lipids remains poorly understood. Here we show the two isoforms of K2P4.1 have distinct binding preferences for lipids dependent on acyl chain length and position on the glycerol backbone. Unexpectedly, the channel can also discriminate the fatty acid linkage at the sn-1 position. Of the 33 lipids interrogated using native mass spectrometry, phosphatidic acid (PA) had the lowest equilibrium dissociation constants for both isoforms of K2P4.1. Liposome potassium flux assays with K2P4.1 reconstituted in defined lipid environments show that those containing PA activate the channel in a dose-dependent fashion. Our results begin to define the molecular requirements for the specific binding of lipids to K2P4.1.
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Clinical Importance of the Human Umbilical Artery Potassium Channels. Cells 2020; 9:cells9091956. [PMID: 32854241 PMCID: PMC7565333 DOI: 10.3390/cells9091956] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/21/2020] [Accepted: 08/24/2020] [Indexed: 02/06/2023] Open
Abstract
Potassium (K+) channels are usually predominant in the membranes of vascular smooth muscle cells (SMCs). These channels play an important role in regulating the membrane potential and vessel contractility-a role that depends on the vascular bed. Thus, the activity of K+ channels represents one of the main mechanisms regulating the vascular tone in physiological and pathophysiological conditions. Briefly, the activation of K+ channels in SMC leads to hyperpolarization and vasorelaxation, while its inhibition induces depolarization and consequent vascular contraction. Currently, there are four different types of K+ channels described in SMCs: voltage-dependent K+ (KV) channels, calcium-activated K+ (KCa) channels, inward rectifier K+ (Kir) channels, and 2-pore domain K+ (K2P) channels. Due to the fundamental role of K+ channels in excitable cells, these channels are promising therapeutic targets in clinical practice. Therefore, this review discusses the basic properties of the various types of K+ channels, including structure, cellular mechanisms that regulate their activity, and new advances in the development of activators and blockers of these channels. The vascular functions of these channels will be discussed with a focus on vascular SMCs of the human umbilical artery. Then, the clinical importance of K+ channels in the treatment and prevention of cardiovascular diseases during pregnancy, such as gestational hypertension and preeclampsia, will be explored.
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46
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Tu N, Liang D, Zhang P. Whole-exome sequencing and genome-wide evolutionary analyses identify novel candidate genes associated with infrared perception in pit vipers. Sci Rep 2020; 10:13033. [PMID: 32747674 PMCID: PMC7400743 DOI: 10.1038/s41598-020-69843-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 07/14/2020] [Indexed: 12/17/2022] Open
Abstract
Pit vipers possess a unique thermal sensory system consisting of facial pits that allow them to detect minute temperature fluctuations within their environments. Biologists have long attempted to elucidate the genetic basis underlying the infrared perception of pit vipers. Early studies have shown that the TRPA1 gene is the thermal sensor associated with infrared detection in pit vipers. However, whether genes other than TRPA1 are also involved in the infrared perception of pit vipers remains unknown. Here, we sequenced the whole exomes of ten snake species and performed genome-wide evolutionary analyses to search for novel candidate genes that might be involved in the infrared perception of pit vipers. We applied both branch-length-comparison and selection-pressure-alteration analyses to identify genes that specifically underwent accelerated evolution in the ancestral lineage of pit vipers. A total of 47 genes were identified. These genes were significantly enriched in the ion transmembrane transporter, stabilization of membrane potential, and temperature gating activity functional categories. The expression levels of these candidate genes in relevant nerve tissues (trigeminal ganglion, dorsal root ganglion, midbrain, and cerebrum) were also investigated in this study. We further chose one of our candidate genes, the potassium channel gene KCNK4, as an example to discuss its possible role in the infrared perception of pit vipers. Our study provides the first genome-wide survey of infrared perception-related genes in pit vipers via comparative evolutionary analyses and reveals valuable candidate genes for future functional studies.
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Affiliation(s)
- Na Tu
- State Key Laboratory of Biocontrol, College of Ecology and Evolution, School of Life Sciences, Higher Education Mega Center, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Dan Liang
- State Key Laboratory of Biocontrol, College of Ecology and Evolution, School of Life Sciences, Higher Education Mega Center, Sun Yat-Sen University, Guangzhou, 510006, China
| | - Peng Zhang
- State Key Laboratory of Biocontrol, College of Ecology and Evolution, School of Life Sciences, Higher Education Mega Center, Sun Yat-Sen University, Guangzhou, 510006, China.
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Fontaine D, Figiel S, Félix R, Kouba S, Fromont G, Mahéo K, Potier-Cartereau M, Chantôme A, Vandier C. Roles of endogenous ether lipids and associated PUFAs in the regulation of ion channels and their relevance for disease. J Lipid Res 2020; 61:840-858. [PMID: 32265321 PMCID: PMC7269763 DOI: 10.1194/jlr.ra120000634] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/29/2020] [Indexed: 12/16/2022] Open
Abstract
Ether lipids (ELs) are lipids characterized by the presence of either an ether linkage (alkyl lipids) or a vinyl ether linkage [i.e., plasmalogens (Pls)] at the sn1 position of the glycerol backbone, and they are enriched in PUFAs at the sn2 position. In this review, we highlight that ELs have various biological functions, act as a reservoir for second messengers (such as PUFAs) and have roles in many diseases. Some of the biological effects of ELs may be associated with their ability to regulate ion channels that control excitation-contraction/secretion/mobility coupling and therefore cell physiology. These channels are embedded in lipid membranes, and lipids can regulate their activities directly or indirectly as second messengers or by incorporating into membranes. Interestingly, ELs and EL-derived PUFAs have been reported to play a key role in several pathologies, including neurological disorders, cardiovascular diseases, and cancers. Investigations leading to a better understanding of their mechanisms of action in pathologies have opened a new field in cancer research. In summary, newly identified lipid regulators of ion channels, such as ELs and PUFAs, may represent valuable targets to improve disease diagnosis and advance the development of new therapeutic strategies for managing a range of diseases and conditions.
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Affiliation(s)
- Delphine Fontaine
- Inserm N2C UMR1069, Université de Tours, F-37032 Tours CEDEX 1, France
| | - Sandy Figiel
- Inserm N2C UMR1069, Université de Tours, F-37032 Tours CEDEX 1, France
| | - Romain Félix
- Inserm N2C UMR1069, Université de Tours, F-37032 Tours CEDEX 1, France
| | - Sana Kouba
- Inserm N2C UMR1069, Université de Tours, F-37032 Tours CEDEX 1, France
| | - Gaëlle Fromont
- Inserm N2C UMR1069, Université de Tours, F-37032 Tours CEDEX 1, France; Department of Pathology, CHRU Bretonneau, F-37044 Tours CEDEX 9, France
| | - Karine Mahéo
- Inserm N2C UMR1069, Université de Tours, F-37032 Tours CEDEX 1, France; Faculté de Pharmacie, Université de Tours, F-37200 Tours, France
| | | | - Aurélie Chantôme
- Inserm N2C UMR1069, Université de Tours, F-37032 Tours CEDEX 1, France; Faculté de Pharmacie, Université de Tours, F-37200 Tours, France
| | - Christophe Vandier
- Inserm N2C UMR1069, Université de Tours, F-37032 Tours CEDEX 1, France. mailto:
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Darkow E, Rog-Zielinska EA, Madl J, Brandel A, Siukstaite L, Omidvar R, Kohl P, Ravens U, Römer W, Peyronnet R. The Lectin LecA Sensitizes the Human Stretch-Activated Channel TREK-1 but Not Piezo1 and Binds Selectively to Cardiac Non-myocytes. Front Physiol 2020; 11:457. [PMID: 32499717 PMCID: PMC7243936 DOI: 10.3389/fphys.2020.00457] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 04/15/2020] [Indexed: 12/16/2022] Open
Abstract
The healthy heart adapts continuously to a complex set of dynamically changing mechanical conditions. The mechanical environment is altered by, and contributes to, multiple cardiac diseases. Mechanical stimuli are detected and transduced by cellular mechano-sensors, including stretch-activated ion channels (SAC). The precise role of SAC in the heart is unclear, in part because there are few SAC-specific pharmacological modulators. That said, most SAC can be activated by inducers of membrane curvature. The lectin LecA is a virulence factor of Pseudomonas aeruginosa and essential for P. aeruginosa-induced membrane curvature, resulting in formation of endocytic structures and bacterial cell invasion. We investigate whether LecA modulates SAC activity. TREK-1 and Piezo1 have been selected, as they are widely expressed in the body, including cardiac tissue, and they are “canonical representatives” for the potassium selective and the cation non-selective SAC families, respectively. Live cell confocal microscopy and electron tomographic imaging were used to follow binding dynamics of LecA, and to track changes in cell morphology and membrane topology in human embryonic kidney (HEK) cells and in giant unilamellar vesicles (GUV). HEK cells were further transfected with human TREK-1 or Piezo1 constructs, and ion channel activity was recorded using the patch-clamp technique. Finally, freshly isolated cardiac cells were used for studies into cell type dependency of LecA binding. LecA (500 nM) binds within seconds to the surface of HEK cells, with highest concentration at cell-cell contact sites. Local membrane invaginations are detected in the presence of LecA, both in the plasma membrane of cells (by 17 min of LecA exposure) as well as in GUV. In HEK cells, LecA sensitizes TREK-1, but not Piezo1, to voltage and mechanical stimulation. In freshly isolated cardiac cells, LecA binds to non-myocytes, but not to ventricular or atrial cardiomyocytes. This cell type specific lack of binding is observed across cardiomyocytes from mouse, rabbit, pig, and human. Our results suggest that LecA may serve as a pharmacological tool to study SAC in a cell type-preferential manner. This could aid tissue-based research into the roles of SAC in cardiac non-myocytes.
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Affiliation(s)
- Elisa Darkow
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Medical Center-University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Eva A Rog-Zielinska
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Medical Center-University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Josef Madl
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Medical Center-University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Annette Brandel
- Faculty of Biology, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Lina Siukstaite
- Faculty of Biology, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Ramin Omidvar
- Faculty of Biology, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Medical Center-University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Ursula Ravens
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Medical Center-University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Winfried Römer
- Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Rémi Peyronnet
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Medical Center-University of Freiburg, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
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Ma R, Lewis A. Spadin Selectively Antagonizes Arachidonic Acid Activation of TREK-1 Channels. Front Pharmacol 2020; 11:434. [PMID: 32317978 PMCID: PMC7154116 DOI: 10.3389/fphar.2020.00434] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 03/20/2020] [Indexed: 12/13/2022] Open
Abstract
TREK-1 channel activity is a critical regulator of neuronal, cardiac, and smooth muscle physiology and pathology. The antidepressant peptide, spadin, has been proposed to be a TREK-1-specific blocker. Here we sought to examine the mechanism of action underlying spadin inhibition of TREK-1 channels. Heterologous expression in Xenopus laevis oocytes and electrophysiological analysis using two-electrode voltage clamp in standard bath solutions was used to characterize the pharmacological profile of wild-type and mutant murine TREK-1 and TREK-2 channels using previously established human K2P activators; arachidonic acid (AA), cis-4,7,10,13,16,19-docosahexaenoic acid (DHA), BL-1249, and cinnamyl-3,4-dihydroxy-α-cyanocinnamate (CDC) and inhibitors; spadin and barium (Ba2+). Mouse TREK-1 and TREK-2 channel currents were both significantly increased by AA, BL-1249, and CDC, similar to their human homologs. Under basal conditions, both TREK-1 and TREK-2 currents were insensitive to application of spadin, but could be blocked by Ba2+. Spadin did not significantly inhibit either TREK-1 or TREK-2 currents either chemically activated by AA, BL-1249, or CDC, or structurally activated via a gating mutation. However, pre-exposure to spadin significantly perturbed the subsequent activation of TREK-1 currents by AA, but not TREK-2. Furthermore, spadin was unable to prevent activation of TREK-1 by BL-1249, CDC, or the related bioactive lipid, DHA. Spadin specifically antagonizes the activation of TREK-1 channels by AA, likely via an allosteric mechanism. Lack of intrinsic activity may explain the absence of clinical side effects during antidepressant therapy.
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Affiliation(s)
- Ruolin Ma
- School of Pharmacy and Biomedical Sciences, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth, United Kingdom
| | - Anthony Lewis
- School of Pharmacy and Biomedical Sciences, Institute of Biomedical and Biomolecular Sciences, University of Portsmouth, Portsmouth, United Kingdom
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50
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Bustos D, Bedoya M, Ramírez D, Concha G, Zúñiga L, Decher N, Hernández-Rodríguez EW, Sepúlveda FV, Martínez L, González W. Elucidating the Structural Basis of the Intracellular pH Sensing Mechanism of TASK-2 K 2P Channels. Int J Mol Sci 2020; 21:ijms21020532. [PMID: 31947679 PMCID: PMC7013731 DOI: 10.3390/ijms21020532] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 12/25/2019] [Accepted: 01/08/2020] [Indexed: 11/23/2022] Open
Abstract
Two-pore domain potassium (K2P) channels maintain the cell’s background conductance by stabilizing the resting membrane potential. They assemble as dimers possessing four transmembrane helices in each subunit. K2P channels were crystallized in “up” and “down” states. The movements of the pore-lining transmembrane TM4 helix produce the aperture or closure of side fenestrations that connect the lipid membrane with the central cavity. When the TM4 helix is in the up-state, the fenestrations are closed, while they are open in the down-state. It is thought that the fenestration states are related to the activity of K2P channels and the opening of the channels preferentially occurs from the up-state. TASK-2, a member of the TALK subfamily of K2P channels, is opened by intracellular alkalization leading the deprotonation of the K245 residue at the end of the TM4 helix. This charge neutralization of K245 could be sensitive or coupled to the fenestration state. Here, we describe the relationship between the states of the intramembrane fenestrations and K245 residue in TASK-2 channel. By using molecular modeling and simulations, we show that the protonated state of K245 (K245+) favors the open fenestration state and, symmetrically, that the open fenestration state favors the protonated state of the lysine residue. We show that the channel can be completely blocked by Prozac, which is known to induce fenestration opening in TREK-2. K245 protonation and fenestration aperture have an additive effect on the conductance of the channel. The opening of the fenestrations with K245+ increases the entrance of lipids into the selectivity filter, blocking the channel. At the same time, the protonation of K245 introduces electrostatic potential energy barriers to ion entrance. We computed the free energy profiles of ion penetration into the channel in different fenestration and K245 protonation states, to show that the effects of the two transformations are summed up, leading to maximum channel blocking. Estimated rates of ion transport are in qualitative agreement with experimental results and support the hypothesis that the most important barrier for ion transport under K245+ and open fenestration conditions is the entrance of the ions into the channel.
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Affiliation(s)
- Daniel Bustos
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca 3460000, Chile; (D.B.); (M.B.)
- Departamento de Computación e Industrias, Facultad de Ciencias de la Ingeniería, Universidad Católica del Maule, Talca 3460000, Chile
| | - Mauricio Bedoya
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca 3460000, Chile; (D.B.); (M.B.)
| | - David Ramírez
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago 8380453, Chile;
| | - Guierdy Concha
- Centro de Investigaciones Médicas, Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile; (G.C.); (L.Z.)
- Magíster en Gestión de Operaciones, Facultad de Ingeniería (Campus Los Niches), Universidad de Talca, Talca 3460000, Chile
| | - Leandro Zúñiga
- Centro de Investigaciones Médicas, Escuela de Medicina, Universidad de Talca, Talca 3460000, Chile; (G.C.); (L.Z.)
- Programa de Investigación Asociativa en Cáncer Gástrico (PIA-CG), Universidad de Talca, Talca 3460000, Chile
| | - Niels Decher
- Institute for Physiology and Pathophysiology, Vegetative Physiology, University of Marburg, D-35037 Marburg, Germany;
| | | | - Francisco V. Sepúlveda
- Centro de Estudios Científicos (CECs), Avenida Arturo Prat 514, Valdivia 5110466, Chile
- Correspondence: (F.V.S.); (L.M.); (W.G.)
| | - Leandro Martínez
- Institute of Chemistry and Center for Computing in Engineering & Science, University of Campinas, Campinas 13083-861 SP, Brazil
- Correspondence: (F.V.S.); (L.M.); (W.G.)
| | - Wendy González
- Centro de Bioinformática y Simulación Molecular, Universidad de Talca, Talca 3460000, Chile; (D.B.); (M.B.)
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, Talca 3460000, Chile
- Correspondence: (F.V.S.); (L.M.); (W.G.)
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