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Lee JM, Kim J, Park SJ, Nam JH, Kim HJ, Kim WK. Regulation of T Lymphocyte Functions through Calcium Signaling Modulation by Nootkatone. Int J Mol Sci 2024; 25:5240. [PMID: 38791278 PMCID: PMC11121628 DOI: 10.3390/ijms25105240] [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: 04/03/2024] [Revised: 05/02/2024] [Accepted: 05/06/2024] [Indexed: 05/26/2024] Open
Abstract
Recent advancements in understanding the intricate molecular mechanisms underlying immunological responses have underscored the critical involvement of ion channels in regulating calcium influx, particularly in inflammation. Nootkatone, a natural sesquiterpenoid found in Alpinia oxyphylla and various citrus species, has gained attention for its diverse pharmacological properties, including anti-inflammatory effects. This study aimed to elucidate the potential of nootkatone in modulating ion channels associated with calcium signaling, particularly CRAC, KV1.3, and KCa3.1 channels, which play pivotal roles in immune cell activation and proliferation. Using electrophysiological techniques, we demonstrated the inhibitory effects of nootkatone on CRAC, KV1.3, and KCa3.1 channels in HEK293T cells overexpressing respective channel proteins. Nootkatone exhibited dose-dependent inhibition of channel currents, with IC50 values determined for each channel. Nootkatone treatment did not significantly affect cell viability, indicating its potential safety for therapeutic applications. Furthermore, we observed that nootkatone treatment attenuated calcium influx through activated CRAC channels and showed anti-proliferative effects, suggesting its role in regulating inflammatory T cell activation. These findings highlight the potential of nootkatone as a natural compound for modulating calcium signaling pathways by targeting related key ion channels and it holds promise as a novel therapeutic agent for inflammatory disorders.
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Affiliation(s)
- Ji Min Lee
- Department of Physiology, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju 38066, Gyeongsangbuk-do, Republic of Korea; (J.M.L.); (S.J.P.); (J.H.N.)
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, 32 Dongguk-ro, Ilsan Dong-gu, Goyang 10326, Gyeonggi-do, Republic of Korea;
| | - Jintae Kim
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, 32 Dongguk-ro, Ilsan Dong-gu, Goyang 10326, Gyeonggi-do, Republic of Korea;
| | - Su Jin Park
- Department of Physiology, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju 38066, Gyeongsangbuk-do, Republic of Korea; (J.M.L.); (S.J.P.); (J.H.N.)
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, 32 Dongguk-ro, Ilsan Dong-gu, Goyang 10326, Gyeonggi-do, Republic of Korea;
| | - Joo Hyun Nam
- Department of Physiology, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju 38066, Gyeongsangbuk-do, Republic of Korea; (J.M.L.); (S.J.P.); (J.H.N.)
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, 32 Dongguk-ro, Ilsan Dong-gu, Goyang 10326, Gyeonggi-do, Republic of Korea;
| | - Hyun Jong Kim
- Department of Physiology, Dongguk University College of Medicine, 123 Dongdae-ro, Gyeongju 38066, Gyeongsangbuk-do, Republic of Korea; (J.M.L.); (S.J.P.); (J.H.N.)
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, 32 Dongguk-ro, Ilsan Dong-gu, Goyang 10326, Gyeonggi-do, Republic of Korea;
| | - Woo Kyung Kim
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, 32 Dongguk-ro, Ilsan Dong-gu, Goyang 10326, Gyeonggi-do, Republic of Korea;
- Department of Internal Medicine, Graduate School of Medicine, Dongguk University, 27 Dongguk-ro, Ilsan Dong-gu, Goyang 10326, Gyeonggi-do, Republic of Korea
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Tang W, Peng J, Chen L, Yu C, Wang Y, Zou F, Zheng G, Meng X. Lead inhibits microglial cell migration via suppression of store-operated calcium entry. Toxicol Lett 2024; 393:69-77. [PMID: 38281554 DOI: 10.1016/j.toxlet.2024.01.011] [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: 01/24/2023] [Revised: 01/05/2024] [Accepted: 01/22/2024] [Indexed: 01/30/2024]
Abstract
Lead (Pb) is a non-biodegradable environmental pollutant that can lead to neurotoxicity by inducing neuroinflammation. Microglial activation plays a key role in neuroinflammation, and microglial migration is one of its main features. However, whether Pb affects microglial migration has not yet been elucidated. Herein, the effect of Pb on microglial migration was investigated using BV-2 microglial cells and primary microglial cells. The results showed that cell activation markers (TNF-α and CD206) in BV-2 cells were increased after Pb treatment. The migration ability of microglia was inhibited by Pb. Both store-operated calcium entry (SOCE) and the Ca2+ release-activated Ca2+ (CRAC) current were downregulated by microglia treatment with Pb in a dose-dependent manner. However, there was no statistical difference in the protein levels of stromal interaction molecule (STIM) 1, STIM2, or Ca2+ release-activated Ca2+ channel protein (Orai) 1 in microglia. The external Ca2+ influx and cell migration ability were restored to a certain extent after overexpression of either STIM1 or its CRAC activation domain in microglia. These results indicated that Pb inhibits microglial migration by downregulation of SOCE and impairment of the function of STIM1.
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Affiliation(s)
- Wei Tang
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China; Department of Occupational & Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an 710032, China
| | - Jiawen Peng
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China; Department of Occupational & Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an 710032, China
| | - Lixuan Chen
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China; Department of Occupational & Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an 710032, China
| | - Changhui Yu
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China; Department of Occupational & Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an 710032, China
| | - Yuhao Wang
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China; Department of Occupational & Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an 710032, China
| | - Fei Zou
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China; Department of Occupational & Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an 710032, China
| | - Gang Zheng
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China; Department of Occupational & Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an 710032, China
| | - Xiaojing Meng
- Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China; Department of Occupational & Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, Xi'an 710032, China.
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3
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Numata T, Sato-Numata K, Yoshino M. Intermediate conductance Ca 2+-activated potassium channels are activated by functional coupling with stretch-activated nonselective cation channels in cricket myocytes. FRONTIERS IN INSECT SCIENCE 2023; 2:1100671. [PMID: 38468799 PMCID: PMC10926553 DOI: 10.3389/finsc.2022.1100671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 12/20/2022] [Indexed: 03/13/2024]
Abstract
Cooperative gating of localized ion channels ranges from fine-tuning excitation-contraction coupling in muscle cells to controlling pace-making activity in the heart. Membrane deformation resulting from muscle contraction activates stretch-activated (SA) cation channels. The subsequent Ca2+ influx activates spatially localized Ca2+-sensitive K+ channels to fine-tune spontaneous muscle contraction. To characterize endogenously expressed intermediate conductance Ca2+-activated potassium (IK) channels and assess the functional relevance of the extracellular Ca2+ source leading to IK channel activity, we performed patch-clamp techniques on cricket oviduct myocytes and recorded single-channel data. In this study, we first investigated the identification of IK channels that could be distinguished from endogenously expressed large-conductance Ca2+-activated potassium (BK) channels by adding extracellular Ba2+. The single-channel conductance of the IK channel was 62 pS, and its activity increased with increasing intracellular Ca2+ concentration but was not voltage-dependent. These results indicated that IK channels are endogenously expressed in cricket oviduct myocytes. Second, the Ca2+ influx pathway that activates the IK channel was investigated. The absence of extracellular Ca2+ or the presence of Gd3+ abolished the activity of IK channels. Finally, we investigated the proximity between SA and IK channels. The removal of extracellular Ca2+, administration of Ca2+ to the microscopic region in a pipette, and application of membrane stretching stimulation increased SA channel activity, followed by IK channel activity. Membrane stretch-induced SA and IK channel activity were positively correlated. However, the emergence of IK channel activity and its increase in response to membrane mechanical stretch was not observed without Ca2+ in the pipette. These results strongly suggest that IK channels are endogenously expressed in cricket oviduct myocytes and that IK channel activity is regulated by neighboring SA channel activity. In conclusion, functional coupling between SA and IK channels may underlie the molecular basis of spontaneous rhythmic contractions.
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Affiliation(s)
- Tomohiro Numata
- Department of Integrative Physiology, Graduate School of Medicine, Akita University, Akita, Japan
- Department of Biology, Tokyo Gakugei University, Tokyo, Japan
| | - Kaori Sato-Numata
- Department of Integrative Physiology, Graduate School of Medicine, Akita University, Akita, Japan
- Department of Biology, Tokyo Gakugei University, Tokyo, Japan
| | - Masami Yoshino
- Department of Biology, Tokyo Gakugei University, Tokyo, Japan
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Chun BJ, Aryal SP, Varughese P, Sun B, Bruno JA, Richards CI, Bachstetter AD, Kekenes-Huskey PM. Purinoreceptors and ectonucleotidases control ATP-induced calcium waveforms and calcium-dependent responses in microglia: Roles of P2 receptors and CD39 in ATP-stimulated microglia. Front Physiol 2023; 13:1037417. [PMID: 36699679 PMCID: PMC9868579 DOI: 10.3389/fphys.2022.1037417] [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: 09/05/2022] [Accepted: 12/12/2022] [Indexed: 01/11/2023] Open
Abstract
Adenosine triphosphate (ATP) and its metabolites drive microglia migration and cytokine production by activating P2X- and P2Y- class purinergic receptors. Purinergic receptor activation gives rise to diverse intracellular calcium (Ca2+ signals, or waveforms, that differ in amplitude, duration, and frequency. Whether and how these characteristics of diverse waveforms influence microglia function is not well-established. We developed a computational model trained with data from published primary murine microglia studies. We simulate how purinoreceptors influence Ca2+ signaling and migration, as well as, how purinoreceptor expression modifies these processes. Our simulation confirmed that P2 receptors encode the amplitude and duration of the ATP-induced Ca2+ waveforms. Our simulations also implicate CD39, an ectonucleotidase that rapidly degrades ATP, as a regulator of purinergic receptor-induced Ca2+ responses. Namely, it was necessary to account for CD39 metabolism of ATP to align the model's predicted purinoreceptor responses with published experimental data. In addition, our modeling results indicate that small Ca2+ transients accompany migration, while large and sustained transients are needed for cytokine responses. Lastly, as a proof-of-principal, we predict Ca2+ transients and cell membrane displacements in a BV2 microglia cell line using published P2 receptor mRNA data to illustrate how our computer model may be extrapolated to other microglia subtypes. These findings provide important insights into how differences in purinergic receptor expression influence microglial responses to ATP.
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Affiliation(s)
- Byeong J. Chun
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, IL, United States,*Correspondence: Byeong J. Chun, ; Peter M. Kekenes-Huskey,
| | - Surya P. Aryal
- Department of Chemistry, University of Kentucky, Lexington, KY, United States
| | - Peter Varughese
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, IL, United States
| | - Bin Sun
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, IL, United States
| | - Joshua A. Bruno
- Department of Physics, Loyola University Chicago, Chicago, IL, United States
| | - Chris I. Richards
- Department of Chemistry, University of Kentucky, Lexington, KY, United States
| | | | - Peter M. Kekenes-Huskey
- Department of Cell and Molecular Physiology, Loyola University Chicago, Chicago, IL, United States,*Correspondence: Byeong J. Chun, ; Peter M. Kekenes-Huskey,
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Massenzio F, Cambiaghi M, Marchiotto F, Boriero D, Limatola C, D’Alessandro G, Buffelli M. In vivo morphological alterations of TAMs during KCa3.1 inhibition-by using in vivo two-photon time-lapse technology. Front Cell Neurosci 2022; 16:1002487. [PMID: 36589283 PMCID: PMC9798303 DOI: 10.3389/fncel.2022.1002487] [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: 07/25/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022] Open
Abstract
Tumor associated macrophages (TAMs) are the mostprevalent cells recruited in the tumor microenvironment (TME). Once recruited, TAMs acquire a pro-tumor phenotype characterized by a typical morphology: ameboid in the tumor core and with larger soma and thick branches in the tumor periphery. Targeting TAMs by reverting them to an anti-tumor phenotype is a promising strategy for cancer immunotherapy. Taking advantage of Cx3cr1GFP/WT heterozygous mice implanted with murine glioma GL261-RFP cells we investigated the role of Ca2+-activated K+ channel (KCa3.1) on the phenotypic shift of TAMs at the late stage of glioma growth through in vivo two-photon imaging. We demonstrated that TAMs respond promptly to KCa3.1 inhibition using a selective inhibitor of the channel (TRAM-34) in a time-dependent manner by boosting ramified projections attributable to a less hypertrophic phenotype in the tumor core. We also revealed a selective effect of drug treatment by reducing both glioma cells and TAMs in the tumor core with no interference with surrounding cells. Taken together, our data indicate a TRAM-34-dependent progressive morphological transformation of TAMs toward a ramified and anti-tumor phenotype, suggesting that the timing of KCa3.1 inhibition is a key point to allow beneficial effects on TAMs.
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Affiliation(s)
- Francesca Massenzio
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy,*Correspondence: Mario Buffelli Francesca Massenzio
| | - Marco Cambiaghi
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Federica Marchiotto
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Diana Boriero
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Cristina Limatola
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy,IRCCS Neuromed, Pozzilli, Italy
| | - Giuseppina D’Alessandro
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy,IRCCS Neuromed, Pozzilli, Italy
| | - Mario Buffelli
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy,*Correspondence: Mario Buffelli Francesca Massenzio
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Maltan L, Andova AM, Derler I. The Role of Lipids in CRAC Channel Function. Biomolecules 2022; 12:biom12030352. [PMID: 35327543 PMCID: PMC8944985 DOI: 10.3390/biom12030352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/12/2022] [Accepted: 02/20/2022] [Indexed: 11/28/2022] Open
Abstract
The composition and dynamics of the lipid membrane define the physical properties of the bilayer and consequently affect the function of the incorporated membrane transporters, which also applies for the prominent Ca2+ release-activated Ca2+ ion channel (CRAC). This channel is activated by receptor-induced Ca2+ store depletion of the endoplasmic reticulum (ER) and consists of two transmembrane proteins, STIM1 and Orai1. STIM1 is anchored in the ER membrane and senses changes in the ER luminal Ca2+ concentration. Orai1 is the Ca2+-selective, pore-forming CRAC channel component located in the plasma membrane (PM). Ca2+ store-depletion of the ER triggers activation of STIM1 proteins, which subsequently leads to a conformational change and oligomerization of STIM1 and its coupling to as well as activation of Orai1 channels at the ER-PM contact sites. Although STIM1 and Orai1 are sufficient for CRAC channel activation, their efficient activation and deactivation is fine-tuned by a variety of lipids and lipid- and/or ER-PM junction-dependent accessory proteins. The underlying mechanisms for lipid-mediated CRAC channel modulation as well as the still open questions, are presented in this review.
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Tiffner A, Hopl V, Schober R, Sallinger M, Grabmayr H, Höglinger C, Fahrner M, Lunz V, Maltan L, Frischauf I, Krivic D, Bhardwaj R, Schindl R, Hediger MA, Derler I. Orai1 Boosts SK3 Channel Activation. Cancers (Basel) 2021; 13:6357. [PMID: 34944977 PMCID: PMC8699475 DOI: 10.3390/cancers13246357] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 12/13/2021] [Indexed: 12/20/2022] Open
Abstract
The interplay of SK3, a Ca2+ sensitive K+ ion channel, with Orai1, a Ca2+ ion channel, has been reported to increase cytosolic Ca2+ levels, thereby triggering proliferation of breast and colon cancer cells, although a molecular mechanism has remained elusive to date. We show in the current study, via heterologous protein expression, that Orai1 can enhance SK3 K+ currents, in addition to constitutively bound calmodulin (CaM). At low cytosolic Ca2+ levels that decrease SK3 K+ permeation, co-expressed Orai1 potentiates SK3 currents. This positive feedback mechanism of SK3 and Orai1 is enabled by their close co-localization. Remarkably, we discovered that loss of SK3 channel activity due to overexpressed CaM mutants could be restored by Orai1, likely via its interplay with the SK3-CaM binding site. Mapping for interaction sites within Orai1, we identified that the cytosolic strands and pore residues are critical for a functional communication with SK3. Moreover, STIM1 has a bimodal role in SK3-Orai1 regulation. Under physiological ionic conditions, STIM1 is able to impede SK3-Orai1 interplay by significantly decreasing their co-localization. Forced STIM1-Orai1 activity and associated Ca2+ influx promote SK3 K+ currents. The dynamic regulation of Orai1 to boost endogenous SK3 channels was also determined in the human prostate cancer cell line LNCaP.
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Affiliation(s)
- Adéla Tiffner
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Valentina Hopl
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Romana Schober
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
- Gottfried Schatz Research Centre, Medical University of Graz, A-8010 Graz, Austria; (D.K.); (R.S.)
| | - Matthias Sallinger
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Herwig Grabmayr
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Carmen Höglinger
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Marc Fahrner
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Victoria Lunz
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Lena Maltan
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Irene Frischauf
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
| | - Denis Krivic
- Gottfried Schatz Research Centre, Medical University of Graz, A-8010 Graz, Austria; (D.K.); (R.S.)
| | - Rajesh Bhardwaj
- Department of Nephrology and Hypertension, University of Bern, Inselspital, Freiburgstrasse 15, CH-3010 Bern, Switzerland; (R.B.); (M.A.H.)
- Department of Biomedical Research, University of Bern, Inselspital, Freiburgstrasse 15, CH-3010 Bern, Switzerland
| | - Rainer Schindl
- Gottfried Schatz Research Centre, Medical University of Graz, A-8010 Graz, Austria; (D.K.); (R.S.)
| | - Matthias A. Hediger
- Department of Nephrology and Hypertension, University of Bern, Inselspital, Freiburgstrasse 15, CH-3010 Bern, Switzerland; (R.B.); (M.A.H.)
- Department of Biomedical Research, University of Bern, Inselspital, Freiburgstrasse 15, CH-3010 Bern, Switzerland
| | - Isabella Derler
- JKU Life Science Center, Institute of Biophysics, Johannes Kepler University Linz, A-4020 Linz, Austria; (A.T.); (V.H.); (R.S.); (M.S.); (H.G.); (C.H.); (M.F.); (V.L.); (L.M.); (I.F.)
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8
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Langthaler S, Rienmüller T, Scheruebel S, Pelzmann B, Shrestha N, Zorn-Pauly K, Schreibmayer W, Koff A, Baumgartner C. A549 in-silico 1.0: A first computational model to simulate cell cycle dependent ion current modulation in the human lung adenocarcinoma. PLoS Comput Biol 2021; 17:e1009091. [PMID: 34157016 PMCID: PMC8219159 DOI: 10.1371/journal.pcbi.1009091] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Accepted: 05/18/2021] [Indexed: 11/18/2022] Open
Abstract
Lung cancer is still a leading cause of death worldwide. In recent years, knowledge has been obtained of the mechanisms modulating ion channel kinetics and thus of cell bioelectric properties, which is promising for oncological biomarkers and targets. The complex interplay of channel expression and its consequences on malignant processes, however, is still insufficiently understood. We here introduce the first approach of an in-silico whole-cell ion current model of a cancer cell, in particular of the A549 human lung adenocarcinoma, including the main functionally expressed ion channels in the plasma membrane as so far known. This hidden Markov-based model represents the electrophysiology behind proliferation of the A549 cell, describing its rhythmic oscillation of the membrane potential able to trigger the transition between cell cycle phases, and it predicts membrane potential changes over the cell cycle provoked by targeted ion channel modulation. This first A549 in-silico cell model opens up a deeper insight and understanding of possible ion channel interactions in tumor development and progression, and is a valuable tool for simulating altered ion channel function in lung cancer electrophysiology. Advances in the understanding of functional alterations at genetic, epigenetic or protein expression and the expanding knowledge in mechanisms modulating ion channel kinetics and thus the cells’ bioelectric properties have arisen as promising cancer biomarkers and oncological targets. Our hidden Markov-based in-silico cell model represents the electrophysiology behind proliferation of the A549 cell line, explaining the cell’s rhythmic oscillation from hyperpolarized to depolarized states of the membrane potential, able to trigger the transition between cell cycle phases. The model enables the prediction of membrane potential changes over the cell cycle provoked by targeted modulation of specific ion channels, leading to cell cycle promotion or interruption. We are encouraged that the availability of this first cancer cell model will provide profound insight into possible roles and interactions of ion channels in tumor development and progression, and may aid in the testing of research hypotheses in lung cancer electrophysiology.
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Affiliation(s)
- Sonja Langthaler
- Institute of Health Care Engineering with European Testing Center for Medical Devices, Graz University of Technology, Graz, Austria
- * E-mail: (SL); (TR); (CB)
| | - Theresa Rienmüller
- Institute of Health Care Engineering with European Testing Center for Medical Devices, Graz University of Technology, Graz, Austria
- * E-mail: (SL); (TR); (CB)
| | - Susanne Scheruebel
- Research Unit on Ion Channels and Cancer Biology, Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Medical University of Graz, Graz, Austria
| | - Brigitte Pelzmann
- Research Unit on Ion Channels and Cancer Biology, Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Medical University of Graz, Graz, Austria
| | - Niroj Shrestha
- Research Unit on Ion Channels and Cancer Biology, Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Medical University of Graz, Graz, Austria
| | - Klaus Zorn-Pauly
- Research Unit on Ion Channels and Cancer Biology, Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Medical University of Graz, Graz, Austria
| | - Wolfgang Schreibmayer
- Research Unit on Ion Channels and Cancer Biology, Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Medical University of Graz, Graz, Austria
| | - Andrew Koff
- Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York City, New York, United States of America
| | - Christian Baumgartner
- Institute of Health Care Engineering with European Testing Center for Medical Devices, Graz University of Technology, Graz, Austria
- * E-mail: (SL); (TR); (CB)
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9
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Maksoud MJE, Tellios V, Xiang YY, Lu WY. Nitric oxide displays a biphasic effect on calcium dynamics in microglia. Nitric Oxide 2021; 108:28-39. [PMID: 33418057 DOI: 10.1016/j.niox.2021.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 11/11/2020] [Accepted: 01/01/2021] [Indexed: 01/13/2023]
Abstract
Calcium is a critical secondary messenger in microglia. In response to inflammation, microglia mobilize intracellular calcium and increase the expression of inducible nitric oxide synthase (iNOS), which produces nitric oxide (NO). This study set to explore whether NO regulates intracellular calcium dynamics through transient receptor potential (TRP) channels in primary wildtype (WT) and iNOS knockout (iNOS-/-) microglia, and the BV2 microglial cell line using calcium imaging and voltage-clamp recordings. Our results demonstrated that application of the NO-donor SNAP induced a biphasic calcium response in naïve murine microglia. Specifically, phase I was characterized by a rapid decline in calcium influx that was attenuated by pretreatment of the store operated calcium channel (SOCC) inhibitor 2APB, while phase II presented as a slow calcium influx that was abolished by pretreatment with the TRP vanilloid type 2 (TRPV2) channel inhibitor tranilast. Importantly, in the presence of a protein kinase G (PKG) inhibitor, the SNAP-mediated calcium decline in phase I persisted while the calcium influx in phase II was abolished. Application of thapsigargin to activate SOCCs caused a calcium influx through a nonselective cation conductance in BV2 microglia, which was abruptly attenuated by SNAP. Importantly, iNOS-/- microglia displayed a significantly larger calcium influx though SOCCs while expressing less stromal interaction molecule 1, Orai1, and TRP canonical type 1 and 3 mRNA, when compared to WT microglia. Together, these results demonstrate that NO signaling restricts calcium influx through SOCCs independent of PKG signaling and increases calcium influx through TRPV2 channels in a PKG-dependent mechanism in microglia.
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Affiliation(s)
- Matthew J E Maksoud
- Graduate Program of Neuroscience, The University of Western Ontario, Canada; Robarts Research Institute, The University of Western Ontario, Canada.
| | - Vasiliki Tellios
- Graduate Program of Neuroscience, The University of Western Ontario, Canada; Robarts Research Institute, The University of Western Ontario, Canada.
| | - Yun-Yan Xiang
- Robarts Research Institute, The University of Western Ontario, Canada.
| | - Wei-Yang Lu
- Graduate Program of Neuroscience, The University of Western Ontario, Canada; Robarts Research Institute, The University of Western Ontario, Canada; Department of Physiology and Pharmacology, University of Western Ontario, Canada.
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10
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Berlansky S, Humer C, Sallinger M, Frischauf I. More Than Just Simple Interaction between STIM and Orai Proteins: CRAC Channel Function Enabled by a Network of Interactions with Regulatory Proteins. Int J Mol Sci 2021; 22:E471. [PMID: 33466526 PMCID: PMC7796502 DOI: 10.3390/ijms22010471] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 12/29/2020] [Accepted: 12/29/2020] [Indexed: 12/27/2022] Open
Abstract
The calcium-release-activated calcium (CRAC) channel, activated by the release of Ca2+ from the endoplasmic reticulum (ER), is critical for Ca2+ homeostasis and active signal transduction in a plethora of cell types. Spurred by the long-sought decryption of the molecular nature of the CRAC channel, considerable scientific effort has been devoted to gaining insights into functional and structural mechanisms underlying this signalling cascade. Key players in CRAC channel function are the Stromal interaction molecule 1 (STIM1) and Orai1. STIM1 proteins span through the membrane of the ER, are competent in sensing luminal Ca2+ concentration, and in turn, are responsible for relaying the signal of Ca2+ store-depletion to pore-forming Orai1 proteins in the plasma membrane. A direct interaction of STIM1 and Orai1 allows for the re-entry of Ca2+ from the extracellular space. Although much is already known about the structure, function, and interaction of STIM1 and Orai1, there is growing evidence that CRAC under physiological conditions is dependent on additional proteins to function properly. Several auxiliary proteins have been shown to regulate CRAC channel activity by means of direct interactions with STIM1 and/or Orai1, promoting or hindering Ca2+ influx in a mechanistically diverse manner. Various proteins have also been identified to exert a modulatory role on the CRAC signalling cascade although inherently lacking an affinity for both STIM1 and Orai1. Apart from ubiquitously expressed representatives, a subset of such regulatory mechanisms seems to allow for a cell-type-specific control of CRAC channel function, considering the rather restricted expression patterns of the specific proteins. Given the high functional and clinical relevance of both generic and cell-type-specific interacting networks, the following review shall provide a comprehensive summary of regulators of the multilayered CRAC channel signalling cascade. It also includes proteins expressed in a narrow spectrum of cells and tissues that are often disregarded in other reviews of similar topics.
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Affiliation(s)
| | | | | | - Irene Frischauf
- Institute of Biophysics, Johannes Kepler University, 4020 Linz, Austria; (S.B.); (C.H.); (M.S.)
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11
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Umpierre AD, Wu LJ. How microglia sense and regulate neuronal activity. Glia 2020; 69:1637-1653. [PMID: 33369790 DOI: 10.1002/glia.23961] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 12/16/2022]
Abstract
Microglia are innate immune cells of the central nervous system that sense extracellular cues. Brain injuries, inflammation, and pathology evoke dynamic structural responses in microglia, altering their morphology and motility. The dynamic motility of microglia is hypothesized to be a critical first step in sensing local alterations and engaging in pattern-specific responses. Alongside their pathological responses, microglia also sense and regulate neuronal activity. In this review, we consider the extracellular molecules, receptors, and mechanisms that allow microglia to sense neuronal activity changes under both hypoactivity and hyperactivity. We also highlight emerging in vivo evidence that microglia regulate neuronal activity, ranging from physiological to pathophysiological conditions. In addition, we discuss the emerging role of calcium signaling in microglial responses to the extracellular environment. The dynamic function of microglia in monitoring and influencing neuronal activity may be critical for brain homeostasis and circuit modification in health and disease.
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Affiliation(s)
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA.,Department of Neuroscience, Mayo Clinic, Jacksonville, Florida, USA.,Department of Immunology, Mayo Clinic, Rochester, Minnesota, USA
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12
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Tiffner A, Derler I. Molecular Choreography and Structure of Ca 2+ Release-Activated Ca 2+ (CRAC) and K Ca2+ Channels and Their Relevance in Disease with Special Focus on Cancer. MEMBRANES 2020; 10:membranes10120425. [PMID: 33333945 PMCID: PMC7765462 DOI: 10.3390/membranes10120425] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/04/2020] [Accepted: 12/07/2020] [Indexed: 12/16/2022]
Abstract
Ca2+ ions play a variety of roles in the human body as well as within a single cell. Cellular Ca2+ signal transduction processes are governed by Ca2+ sensing and Ca2+ transporting proteins. In this review, we discuss the Ca2+ and the Ca2+-sensing ion channels with particular focus on the structure-function relationship of the Ca2+ release-activated Ca2+ (CRAC) ion channel, the Ca2+-activated K+ (KCa2+) ion channels, and their modulation via other cellular components. Moreover, we highlight their roles in healthy signaling processes as well as in disease with a special focus on cancer. As KCa2+ channels are activated via elevations of intracellular Ca2+ levels, we summarize the current knowledge on the action mechanisms of the interplay of CRAC and KCa2+ ion channels and their role in cancer cell development.
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13
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Wu T, Yin N, Chen X, Huang H, Liao Y. Functional coupling between BKCa and SOC channels. Tissue Cell 2020; 66:101394. [DOI: 10.1016/j.tice.2020.101394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 05/31/2020] [Accepted: 05/31/2020] [Indexed: 01/13/2023]
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14
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Nguyen HM, di Lucente J, Chen YJ, Cui Y, Ibrahim RH, Pennington MW, Jin LW, Maezawa I, Wulff H. Biophysical basis for Kv1.3 regulation of membrane potential changes induced by P2X4-mediated calcium entry in microglia. Glia 2020; 68:2377-2394. [PMID: 32525239 PMCID: PMC7540709 DOI: 10.1002/glia.23847] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Revised: 04/17/2020] [Accepted: 05/07/2020] [Indexed: 12/02/2022]
Abstract
Microglia‐mediated inflammation exerts adverse effects in ischemic stroke and in neurodegenerative disorders such as Alzheimer's disease (AD). Expression of the voltage‐gated potassium channel Kv1.3 is required for microglia activation. Both genetic deletion and pharmacological inhibition of Kv1.3 are effective in reducing microglia activation and the associated inflammatory responses, as well as in improving neurological outcomes in animal models of AD and ischemic stroke. Here we sought to elucidate the molecular mechanisms underlying the therapeutic effects of Kv1.3 inhibition, which remain incompletely understood. Using a combination of whole‐cell voltage‐clamp electrophysiology and quantitative PCR (qPCR), we first characterized a stimulus‐dependent differential expression pattern for Kv1.3 and P2X4, a major ATP‐gated cationic channel, both in vitro and in vivo. We then demonstrated by whole‐cell current‐clamp experiments that Kv1.3 channels contribute not only to setting the resting membrane potential but also play an important role in counteracting excessive membrane potential changes evoked by depolarizing current injections. Similarly, the presence of Kv1.3 channels renders microglia more resistant to depolarization produced by ATP‐mediated P2X4 receptor activation. Inhibiting Kv1.3 channels with ShK‐223 completely nullified the ability of Kv1.3 to normalize membrane potential changes, resulting in excessive depolarization and reduced calcium transients through P2X4 receptors. Our report thus links Kv1.3 function to P2X4 receptor‐mediated signaling as one of the underlying mechanisms by which Kv1.3 blockade reduces microglia‐mediated inflammation. While we could confirm previously reported differences between males and females in microglial P2X4 expression, microglial Kv1.3 expression exhibited no gender differences in vitro or in vivo. Main Points The voltage‐gated K+ channel Kv1.3 regulates microglial membrane potential. Inhibition of Kv1.3 depolarizes microglia and reduces calcium entry mediated by P2X4 receptors by dissipating the electrochemical driving force for calcium.
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Affiliation(s)
- Hai M Nguyen
- Department of Pharmacology, University of California, Davis, California, USA
| | - Jacopo di Lucente
- Department of Pathology and Laboratory Medicine and M.I.N.D. Institute, University of California Davis Medical Center, Sacramento, California, USA
| | - Yi-Je Chen
- Department of Pharmacology, University of California, Davis, California, USA
| | - Yanjun Cui
- Department of Pharmacology, University of California, Davis, California, USA
| | - Rania H Ibrahim
- Department of Pharmacology, University of California, Davis, California, USA
| | | | - Lee-Way Jin
- Department of Pathology and Laboratory Medicine and M.I.N.D. Institute, University of California Davis Medical Center, Sacramento, California, USA
| | - Izumi Maezawa
- Department of Pathology and Laboratory Medicine and M.I.N.D. Institute, University of California Davis Medical Center, Sacramento, California, USA
| | - Heike Wulff
- Department of Pharmacology, University of California, Davis, California, USA
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15
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Echeverry S, Grismaldo A, Sánchez C, Sierra C, Henao JC, Granados ST, Sutachán JJ, Torres YP. Activation of BK Channel Contributes to PL-Induced Mesenchymal Stem Cell Migration. Front Physiol 2020; 11:210. [PMID: 32265729 PMCID: PMC7105713 DOI: 10.3389/fphys.2020.00210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 02/24/2020] [Indexed: 01/16/2023] Open
Abstract
Due to their capacity to proliferate, migrate, and differentiate, mesenchymal stem cells (MSCs) are considered to be good candidates for regenerative medicine applications. The mechanisms underlying proliferation and differentiation of MSCs have been studied. However, much less is known about the mechanisms regulating the migration of MSCs. Platelet lysate (PL), a supplement used to promote cell expansion, has been shown to promote MSCs migration; however, the underlying mechanism are unknown. Here, by using adipose-derived rat MSCs (rMSCs) and the scratch assay in the absence and presence of various BK channels modulators, we evaluated the role of BK channels in mediating the PL-stimulated migration of rMSCs. We found that 5% PL increased rMSCs migration, and this effect was blocked by the addition of the BK channel selective antagonist Iberiotoxin (IBTX). In the absence of PL, the BK channel agonist NS1619, stimulated rMSCs migration to similar level as 5% PL. Addition of both NS1619 and 5% PL resulted in an increase in rMSCs migration, that was higher than when either one was added individually. From whole-cell recordings, it was found that the addition of 5% PL increased the magnitude of BK current density. By using Western blot and flow cytometry, it was found that PL did not affect the expression of BK channels. Together, our results indicate that as shown in other cell types, activation of BK channels by themselves also promote rMSC migration, and show that activation of BK channels contribute to the observed PL-induced increase in migration of rMSC.
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16
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Lu J, Dou F, Yu Z. The potassium channel KCa3.1 represents a valid pharmacological target for microgliosis-induced neuronal impairment in a mouse model of Parkinson's disease. J Neuroinflammation 2019; 16:273. [PMID: 31878950 PMCID: PMC6931251 DOI: 10.1186/s12974-019-1682-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 12/17/2019] [Indexed: 12/11/2022] Open
Abstract
Background Recent studies described a critical role for microglia in Parkinson’s disease (PD), where these central nerve system resident immune cells participate in the neuroinflammatory microenvironment that contributes to dopaminergic neurons loss in the substantia nigra. Understanding the phenotype switch of microgliosis in PD could help to identify the molecular mechanism which could attenuate or delay the progressive decline in motor function. KCa3.1 has been reported to regulate the “pro-inflammatory” phenotype switch of microglia in neurodegenerative pathological conditions. Methods We here investigated the effects of gene deletion or pharmacological blockade of KCa3.1 activity in wild-type or KCa3.1−/− mice after treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), a mouse model of PD. MPTP-induced PD mouse model was subjected to the rotarod test to evaluate the locomotor ability. Glia activation and neuron loss were measured by immunostaining. Fluo-4 AM was used to measure cytosolic Ca2+ level in 1-methyl-4-phenylpyridinium (MPP+)-induced microgliosis in vitro. Results We report that treatment of MPTP-induced PD mouse model with gene deletion or pharmacological blockade of KCa3.1 with senicapoc improves the locomotor ability and the tyrosine hydroxylase (TH)-positive neuron number and attenuates the microgliosis and neuroinflammation in the substantia nigra pars compacta (SNpc). KCa3.1 involves in store-operated Ca2+ entry-induced Ca2+ overload and endoplasmic reticulum stress via the protein kinase B (AKT) signaling pathway during microgliosis. Gene deletion or blockade of KCa3.1 restored AKT/mammalian target of rapamycin (mTOR) signaling both in vivo and in vitro. Conclusions Taken together, these results demonstrate a key role for KCa3.1 in driving a pro-inflammatory microglia phenotype in PD.
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Affiliation(s)
- Jia Lu
- Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China
| | - Fangfang Dou
- Basic Research Department, Shanghai Geriatric Institute of Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 200031, China
| | - Zhihua Yu
- Department of Pharmacology and Chemical Biology, Shanghai Jiao Tong University School of Medicine, 280 South Chongqing Road, Shanghai, 200025, China.
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17
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Layhadi JA, Fountain SJ. ATP-Evoked Intracellular Ca 2+ Responses in M-CSF Differentiated Human Monocyte-Derived Macrophage are Mediated by P2X4 and P2Y11 Receptor Activation. Int J Mol Sci 2019; 20:E5113. [PMID: 31618941 PMCID: PMC6834299 DOI: 10.3390/ijms20205113] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 10/09/2019] [Accepted: 10/10/2019] [Indexed: 12/11/2022] Open
Abstract
Tissues differentially secrete multiple colony stimulating factors under conditions of homeostasis and inflammation, orientating recruited circulating monocytes to differentiate to macrophage with differing functional phenotypes. Here, we investigated ATP-evoked intracellular Ca2+ responses in human macrophage differentiated with macrophage colony-stimulating factor (M-CSF). Extracellular ATP evoked (EC50 13.3 ± 1.4 μM) robust biphasic intracellular Ca2+ responses that showed a dependency on both metabotropic (P2Y) and ionotropic (P2X) receptors. qRT-PCR and immunocytochemistry revealed the expression of P2Y1, P2Y2, P2Y6, P2Y11, P2Y13, P2X1, P2X4, P2X5, and P2X7. Pharmacological analysis revealed contribution of only P2X4 and P2Y11 to the Ca2+ response evoked by maximal ATP concentrations (100 µM). This study reveals the contribution of P2X4 and P2Y11 receptor activation to ATP-evoked intracellular Ca2+ responses, and makes comparison with macrophage differentiated using granulocyte colony-stimulating factor (GM-CSF).
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Affiliation(s)
- Janice A Layhadi
- Biomedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
| | - Samuel J Fountain
- Biomedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
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18
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Mohammadi-Rad M, Ghasemi N, Aliomrani M. Evaluation of apamin effects on myelination process in C57BL/6 mice model of multiple sclerosis. Res Pharm Sci 2019; 14:424-431. [PMID: 31798659 PMCID: PMC6827192 DOI: 10.4103/1735-5362.268203] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Multiple sclerosis (MS) is a demyelinating disease that causes chronic inflammation in the central nervous system. The aim of this study was to investigate the effects of apamin administration on myelination process. MS was induced by feeding cuprizone pellets (0.2%) for 6 weeks (demyelination phase) followed by normal feeding for additional 2 weeks (remyelination phase). Briefly, C57BL/6 male mice were randomly divided into six groups. Group 1, received the regular food pellets. Group 2 contained two subgroups of 6 animals each (n = 2 × 6). First group received cuprizone for 6 weeks and the sacrificed while the second group after 6 weeks of cuprizone, received no treatment for additional 2 weeks. Group 3 (co-treatment group) was composed of two subgroups of 6 animals each (n = 2 × 6). Both subgroups received apamin (100 μg/kg) intraperitoneally twice a week for 6 weeks. First subgroup terminated at this time and the second subgroup was fed normal diet for two additional weeks. Group 4 (post-treatment, n = 6) received apamin (100 μg/kg) intraperitoneally twice a week for 2 weeks after cuprizone secession. Groups 5 and 6 (vehicle, n = 6 in each group) received phosphate buffered saline as the vehicle of apamin during demyelination and remyelination phase. At the end of each phase, mice were deeply anesthetized and perfused. Groups 5 and 6 (vehicle) received PBS as the vehicle during both phases. Mice were anesthetized, perfused with PBS through their heart, and their brains were removed. Brain sections stained with luxol fast blue and the images were analyzed. Apamin co-treatment significantly increased the myelin content as compared to the cuprizone group. Also, mild elevation in the myelinated areas was observed with apamin post-treatment in comparison with remyelination phase. Our results revealed that apamin prevents myelin destruction more significantly as compared to remyelination process. This observation explains the possible role of apamin in inhibiting the activation of the microglia cells than stimulation of the oligodendrocytic precursor cells.
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Affiliation(s)
- Maedeh Mohammadi-Rad
- Department of Toxicology and Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| | - Nazem Ghasemi
- Department of Anatomical Sciences, School of Medicine, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
| | - Mehdi Aliomrani
- Department of Toxicology and Pharmacology, Isfahan Pharmaceutical Science Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, I.R. Iran
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19
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Franco-Bocanegra DK, McAuley C, Nicoll JAR, Boche D. Molecular Mechanisms of Microglial Motility: Changes in Ageing and Alzheimer's Disease. Cells 2019; 8:cells8060639. [PMID: 31242692 PMCID: PMC6627151 DOI: 10.3390/cells8060639] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/21/2019] [Accepted: 06/24/2019] [Indexed: 12/25/2022] Open
Abstract
Microglia are the tissue-resident immune cells of the central nervous system, where they constitute the first line of defense against any pathogens or injury. Microglia are highly motile cells and in order to carry out their function, they constantly undergo changes in their morphology to adapt to their environment. The microglial motility and morphological versatility are the result of a complex molecular machinery, mainly composed of mechanisms of organization of the actin cytoskeleton, coupled with a “sensory” system of membrane receptors that allow the cells to perceive changes in their microenvironment and modulate their responses. Evidence points to microglia as accountable for some of the changes observed in the brain during ageing, and microglia have a role in the development of neurodegenerative diseases, such as Alzheimer’s disease. The present review describes in detail the main mechanisms driving microglial motility in physiological conditions, namely, the cytoskeletal actin dynamics, with emphasis in proteins highly expressed in microglia, and the role of chemotactic membrane proteins, such as the fractalkine and purinergic receptors. The review further delves into the changes occurring to the involved proteins and pathways specifically during ageing and in Alzheimer’s disease, analyzing how these changes might participate in the development of this disease.
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Affiliation(s)
- Diana K Franco-Bocanegra
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK.
| | - Ciaran McAuley
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK.
| | - James A R Nicoll
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK.
- Department of Cellular Pathology, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK.
| | - Delphine Boche
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK.
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20
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Role of KCa3.1 Channels in Modulating Ca 2+ Oscillations during Glioblastoma Cell Migration and Invasion. Int J Mol Sci 2018; 19:ijms19102970. [PMID: 30274242 PMCID: PMC6213908 DOI: 10.3390/ijms19102970] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 09/21/2018] [Accepted: 09/25/2018] [Indexed: 01/29/2023] Open
Abstract
Cell migration and invasion in glioblastoma (GBM), the most lethal form of primary brain tumors, are critically dependent on Ca2+ signaling. Increases of [Ca2+]i in GBM cells often result from Ca2+ release from the endoplasmic reticulum (ER), promoted by a variety of agents present in the tumor microenvironment and able to activate the phospholipase C/inositol 1,4,5-trisphosphate PLC/IP3 pathway. The Ca2+ signaling is further strengthened by the Ca2+ influx from the extracellular space through Ca2+ release-activated Ca2+ (CRAC) currents sustained by Orai/STIM channels, meant to replenish the partially depleted ER. Notably, the elevated cytosolic [Ca2+]i activates the intermediate conductance Ca2+-activated K (KCa3.1) channels highly expressed in the plasma membrane of GBM cells, and the resulting K+ efflux hyperpolarizes the cell membrane. This translates to an enhancement of Ca2+ entry through Orai/STIM channels as a result of the increased electromotive (driving) force on Ca2+ influx, ending with the establishment of a recurrent cycle reinforcing the Ca2+ signal. Ca2+ signaling in migrating GBM cells often emerges in the form of intracellular Ca2+ oscillations, instrumental to promote key processes in the migratory cycle. This has suggested that KCa3.1 channels may promote GBM cell migration by inducing or modulating the shape of Ca2+ oscillations. In accordance, we recently built a theoretical model of Ca2+ oscillations incorporating the KCa3.1 channel-dependent dynamics of the membrane potential, and found that the KCa3.1 channel activity could significantly affect the IP3 driven Ca2+ oscillations. Here we review our new theoretical model of Ca2+ oscillations in GBM, upgraded in the light of better knowledge of the KCa3.1 channel kinetics and Ca2+ sensitivity, the dynamics of the Orai/STIM channel modulation, the migration and invasion mechanisms of GBM cells, and their regulation by Ca2+ signals.
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21
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Lively S, Schlichter LC. Microglia Responses to Pro-inflammatory Stimuli (LPS, IFNγ+TNFα) and Reprogramming by Resolving Cytokines (IL-4, IL-10). Front Cell Neurosci 2018; 12:215. [PMID: 30087595 PMCID: PMC6066613 DOI: 10.3389/fncel.2018.00215] [Citation(s) in RCA: 208] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 06/28/2018] [Indexed: 12/11/2022] Open
Abstract
Microglia respond to CNS injuries and diseases with complex reactions, often called "activation." A pro-inflammatory phenotype (also called classical or M1 activation) lies at one extreme of the reactivity spectrum. There were several motivations for this study. First, bacterial endotoxin (lipopolysaccharide, LPS) is the most commonly used pro-inflammatory stimulus for microglia, both in vitro and in vivo; however, pro-inflammatory cytokines (e.g., IFNγ, TNFα) rather than LPS will be encountered with sterile CNS damage and disease. We lack direct comparisons of responses between LPS and such cytokines. Second, while transcriptional profiling is providing substantial data on microglial responses to LPS, these studies mainly use mouse cells and models, and there is increasing evidence that responses of rat microglia can differ. Third, the cytokine milieu is dynamic after acute CNS damage, and an important question in microglial biology is: How malleable are their responses? There are very few studies of effects of resolving cytokines, particularly for rat microglia, and much of the work has focused on pro-inflammatory outcomes. Here, we first exposed primary rat microglia to LPS or to IFNγ+TNFα (I+T) and compared hallmark functional (nitric oxide production, migration) and molecular responses (almost 100 genes), including surface receptors that can be considered part of the sensome. Protein changes for exemplary molecules were also quantified: ARG1, CD206/MRC1, COX-2, iNOS, and PYK2. Despite some similarities, there were notable differences in responses to LPS and I+T. For instance, LPS often evoked higher pro-inflammatory gene expression and also increased several anti-inflammatory genes. Second, we compared the ability of two anti-inflammatory, resolving cytokines (IL-4, IL-10), to counteract responses to LPS and I+T. IL-4 was more effective after I+T than after LPS, and IL-10 was surprisingly ineffective after either stimulus. These results should prove useful in modeling microglial reactivity in vitro; and comparing transcriptional responses to sterile CNS inflammation in vivo.
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Affiliation(s)
- Starlee Lively
- Division of Genetics & Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Lyanne C Schlichter
- Division of Genetics & Development, Krembil Research Institute, University Health Network, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
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22
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Kondo C, Clark RB, Al‐Jezani N, Kim TY, Belke D, Banderali U, Szerencsei RT, Jalloul AH, Schnetkamp PPM, Spitzer KW, Giles WR. ATP triggers a robust intracellular [Ca 2+ ]-mediated signalling pathway in human synovial fibroblasts. Exp Physiol 2018; 103:1101-1122. [PMID: 29791754 DOI: 10.1113/ep086851] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 04/26/2018] [Indexed: 01/05/2023]
Abstract
NEW FINDINGS What is the central question of this study? What are the main [Ca2+ ]i signalling pathways activated by ATP in human synovial fibroblasts? What is the main finding and its importance? In human synovial fibroblasts ATP acts through a linked G-protein (Gq ) and phospholipase C signalling mechanism to produce IP3 , which then markedly enhances release of Ca2+ from the endoplasmic reticulum. These results provide new information for the detection of early pathophysiology of arthritis. ABSTRACT In human articular joints, synovial fibroblasts (HSFs) have essential physiological functions that include synthesis and secretion of components of the extracellular matrix and essential articular joint lubricants, as well as release of paracrine substances such as ATP. Although the molecular and cellular processes that lead to a rheumatoid arthritis (RA) phenotype are not fully understood, HSF cells exhibit significant changes during this disease progression. The effects of ATP on HSFs were studied by monitoring changes in intracellular Ca2+ ([Ca2+ ]i ), and measuring electrophysiological properties. ATP application to HSF cell populations that had been enzymatically released from 2-D cell culture revealed that ATP (10-100 μm), or its analogues UTP or ADP, consistently produced a large transient increase in [Ca2+ ]i . These changes (i) were initiated by activation of the P2 Y purinergic receptor family, (ii) required Gq -mediated signal transduction, (iii) did not involve a transmembrane Ca2+ influx, but instead (iv) arose almost entirely from activation of endoplasmic reticulum (ER)-localized inositol 1,4,5-trisphosphate (IP3 ) receptors that triggered Ca2+ release from the ER. Corresponding single cell electrophysiological studies revealed that these ATP effects (i) were insensitive to [Ca2+ ]o removal, (ii) involved an IP3 -mediated intracellular Ca2+ release process, and (iii) strongly turned on Ca2+ -activated K+ current(s) that significantly hyperpolarized these cells. Application of histamine produced very similar effects in these HSF cells. Since ATP is a known paracrine agonist and histamine is released early in the inflammatory response, these findings may contribute to identification of early steps/defects in the initiation and progression of RA.
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Affiliation(s)
- C Kondo
- Faculty of Kinesiology, University of Calgary, Calgary, Canada
| | - R B Clark
- Faculty of Kinesiology, University of Calgary, Calgary, Canada
| | | | - T Y Kim
- Faculty of Kinesiology, University of Calgary, Calgary, Canada
| | - D Belke
- Cumming School of Medicine, University of Calgary, Calgary, Canada
| | | | - R T Szerencsei
- Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - A H Jalloul
- Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - P P M Schnetkamp
- Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - K W Spitzer
- Nora Eccles Harrison Cardiovascular Centre, Salt Lake City, UT, USA
| | - W R Giles
- Faculty of Kinesiology, University of Calgary, Calgary, Canada.,Faculty of Medicine, University of Calgary, Calgary, Canada
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23
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Lively S, Lam D, Wong R, Schlichter LC. Comparing Effects of Transforming Growth Factor β1 on Microglia From Rat and Mouse: Transcriptional Profiles and Potassium Channels. Front Cell Neurosci 2018; 12:115. [PMID: 29780305 PMCID: PMC5946019 DOI: 10.3389/fncel.2018.00115] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 04/11/2018] [Indexed: 12/02/2022] Open
Abstract
The cytokine, transforming growth factor β1 (TGFβ1), is up-regulated after central nervous system (CNS) injuries or diseases involving microglial activation, and it has been proposed as a therapeutic agent for treating neuroinflammation. Microglia can produce and respond to TGFβ1. While rats and mice are commonly used for studying neuroinflammation, very few reports directly compare them. Such studies are important for improving pre-clinical studies and furthering translational progress in developing therapeutic interventions. After intracerebral hemorrhage (ICH) in the rat striatum, the TGFβ1 receptor was highly expressed on microglia/macrophages within the hematoma. We recently found species similarities and differences in response to either a pro-inflammatory (interferon-γ, IFN-γ, +tumor necrosis factor, TNF-α) or anti-inflammatory interleukin-4 (IL-4) stimulus. Here, we assessed whether rat and mouse microglia differ in their responses to TGFβ1. Microglia were isolated from Sprague-Dawley rats and C57BL/6 mice and treated with TGFβ1. We quantified changes in expression of >50 genes, in their morphology, proliferation, apoptosis and in three potassium channels that are considered therapeutic targets. Many inflammatory mediators, immune receptors and modulators showed species similarities, but notable differences included that, for some genes, only one species responded (e.g., Il4r, Il10, Tgfbr2, colony-stimulating factor receptor (Csf1r), Itgam, suppressor of cytokine signaling 1 (Socs1), toll-like receptors 4 (Tlr4), P2rx7, P2ry12), and opposite responses were seen for others (Tgfb1, Myc, Ifngr1). In rat only, TGFβ1 affected microglial morphology and proliferation, but there was no apoptosis in either species. In both species, TGFβ1 dramatically increased Kv1.3 channel expression and current (no effects on Kir2.1). KCa3.1 showed opposite species responses: the current was low in unstimulated rat microglia and greatly increased by TGFβ1 but higher in control mouse cells and decreased by TGFβ1. Finally, we compared TGFβ1 and IL10 (often considered similar anti-inflammatory stimuli) and found many different responses in both species. Overall, the numerous species differences should be considered when characterizing neuroinflammation and microglial activation in vitro and in vivo, and when targeting potassium channels.
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Affiliation(s)
- Starlee Lively
- Krembil Research Institute, Genes and Development Division, University Health Network, Toronto, ON, Canada
| | - Doris Lam
- Krembil Research Institute, Genes and Development Division, University Health Network, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Raymond Wong
- Krembil Research Institute, Genes and Development Division, University Health Network, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Lyanne C Schlichter
- Krembil Research Institute, Genes and Development Division, University Health Network, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
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24
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Sforna L, Megaro A, Pessia M, Franciolini F, Catacuzzeno L. Structure, Gating and Basic Functions of the Ca2+-activated K Channel of Intermediate Conductance. Curr Neuropharmacol 2018; 16:608-617. [PMID: 28875832 PMCID: PMC5997868 DOI: 10.2174/1570159x15666170830122402] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/21/2017] [Accepted: 07/22/2017] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND The KCa3.1 channel is the intermediate-conductance member of the Ca2+- activated K channel superfamily. It is widely expressed in excitable and non-excitable cells, where it plays a major role in a number of cell functions. This paper aims at illustrating the main structural, biophysical and modulatory properties of the KCa3.1 channel, and providing an account of experimental data on its role in volume regulation and Ca2+ signals. METHODS Research and online content related to the structure, structure/function relationship, and physiological role of the KCa3.1 channel are reviewed. RESULTS Expressed in excitable and non-excitable cells, the KCa3.1 channel is voltage independent, its opening being exclusively gated by the binding of intracellular Ca2+ to calmodulin, a Ca2+- binding protein constitutively associated with the C-terminus of each KCa3.1 channel α subunit. The KCa3.1 channel activates upon high affinity Ca2+ binding, and in highly coordinated fashion giving steep Hill functions and relatively low EC50 values (100-350 nM). This high Ca2+ sensitivity is physiologically modulated by closely associated kinases and phosphatases. The KCa3.1 channel is normally activated by global Ca2+ signals as resulting from Ca2+ released from intracellular stores, or by the refilling influx through store operated Ca2+ channels, but cases of strict functional coupling with Ca2+-selective channels are also found. KCa3.1 channels are highly expressed in many types of cells, where they play major roles in cell migration and death. The control of these complex cellular processes is achieved by KCa3.1 channel regulation of the driving force for Ca2+ entry from the extracellular medium, and by mediating the K+ efflux required for cell volume control. CONCLUSION Much work remains to be done to fully understand the structure/function relationship of the KCa3.1 channels. Hopefully, this effort will provide the basis for a beneficial modulation of channel activity under pathological conditions.
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Affiliation(s)
| | | | | | - Fabio Franciolini
- Address correspondence to these authors at the Department of Chemistry, Biology and Biotechnology, University of Perugia, Via Pascoli, 8-06123, Perugia; Tel: 39.075.585.5751; E-mails: and
| | - Luigi Catacuzzeno
- Address correspondence to these authors at the Department of Chemistry, Biology and Biotechnology, University of Perugia, Via Pascoli, 8-06123, Perugia; Tel: 39.075.585.5751; E-mails: and
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25
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Lam D, Lively S, Schlichter LC. Responses of rat and mouse primary microglia to pro- and anti-inflammatory stimuli: molecular profiles, K + channels and migration. J Neuroinflammation 2017; 14:166. [PMID: 28830445 PMCID: PMC5567442 DOI: 10.1186/s12974-017-0941-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 08/13/2017] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Acute CNS damage is commonly studied using rat and mouse models, but increasingly, molecular analysis is finding species differences that might affect the ability to translate findings to humans. Microglia can undergo complex molecular and functional changes, often studied by in vitro responses to discrete activating stimuli. There is considerable evidence that pro-inflammatory (M1) activation can exacerbate tissue damage, while anti-inflammatory (M2) states help resolve inflammation and promote tissue repair. However, in assessing potential therapeutic targets for controlling inflammation, it is crucial to determine whether rat and mouse microglia respond the same. METHODS Primary microglia from Sprague-Dawley rats and C57BL/6 mice were cultured, then stimulated with interferon-γ + tumor necrosis factor-α (I + T; M1 activation), interleukin (IL)-4 (M2a, alternative activation), or IL-10 (M2c, acquired deactivation). To profile their activation responses, NanoString was used to monitor messenger RNA (mRNA) expression of numerous pro- and anti-inflammatory mediators, microglial markers, immunomodulators, and other molecules. Western analysis was used to measure selected proteins. Two potential targets for controlling inflammation-inward- and outward-rectifier K+ channels (Kir2.1, Kv1.3)-were examined (mRNA, currents) and specific channel blockers were applied to determine their contributions to microglial migration in the different activation states. RESULTS Pro-inflammatory molecules increased after I + T treatment but there were several qualitative and quantitative differences between the species (e.g., iNOS and nitric oxide, COX-2). Several molecules commonly associated with an M2a state differed between species or they were induced in additional activation states (e.g., CD206, ARG1). Resting levels and/or responses of several microglial markers (Iba1, CD11b, CD68) differed with the activation state, species, or both. Transcripts for several Kir2 and Kv1 family members were detected in both species. However, the current amplitudes (mainly Kir2.1 and Kv1.3) depended on activation state and species. Treatment-induced changes in morphology and migratory capacity were similar between the species (migration reduced by I + T, increased by IL-4 or IL-10). In both species, Kir2.1 block reduced migration and Kv1.3 block increased it, regardless of activation state; thus, these channels might affect microglial migration to damage sites. CONCLUSIONS Caution is recommended in generalizing molecular and functional responses of microglia to activating stimuli between species.
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Affiliation(s)
- Doris Lam
- Genes and Development Division, Krembil Research Institute, University Health Network, Krembil Discovery Tower, Room 7KD417, 60 Leonard Avenue, Toronto, ON, M5T 2S8, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Starlee Lively
- Genes and Development Division, Krembil Research Institute, University Health Network, Krembil Discovery Tower, Room 7KD417, 60 Leonard Avenue, Toronto, ON, M5T 2S8, Canada
| | - Lyanne C Schlichter
- Genes and Development Division, Krembil Research Institute, University Health Network, Krembil Discovery Tower, Room 7KD417, 60 Leonard Avenue, Toronto, ON, M5T 2S8, Canada. .,Department of Physiology, University of Toronto, Toronto, ON, Canada.
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26
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Robles-Martínez L, Garay E, Martel-Gallegos MG, Cisneros-Mejorado A, Pérez-Montiel D, Lara A, Arellano RO. K ca3.1 Activation Via P2y 2 Purinergic Receptors Promotes Human Ovarian Cancer Cell (Skov-3) Migration. Sci Rep 2017; 7:4340. [PMID: 28659615 PMCID: PMC5489490 DOI: 10.1038/s41598-017-04292-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 05/12/2017] [Indexed: 01/28/2023] Open
Abstract
Disorders in cell signaling mediated by ATP or histamine, activating specific membrane receptors, have been frequently associated with tumorigenesis. Among the elements of response to purinergic (and histaminergic) signaling, ion channel activation controls essential cellular processes in cancer, such as cell proliferation, motility, and death. Here, we studied the effects that ATP had on electrical properties of human ovarian adenocarcinoma cells named SKOV-3. ATP caused increase in intracellular Ca2+ concentration ([Ca2+]i) and, concurrently, it evoked a complex electrical response with a conspicuous outward component. This current was generated through P2Y2 receptor activation and opening of K+ channels, KCa3.1, as indicated by electrophysiological and pharmacological analysis, as well as by immunodetection and specific silencing of P2Y2 or KCa3.1 gene by esiRNA transfection. Low µM ATP concentration increased SKOV-3 cell migration, which was strongly inhibited by KCa3.1 channel blockers and by esiRNA-generated P2Y2 or KCa3.1 downregulation. Finally, in human ovarian tumors, the P2Y2 and KCa3.1 proteins are expressed and co-localized in neoplastic cells. Thus, stimulation of P2Y2 receptors expressed in SKOV-3 cells promotes motility through KCa3.1 activation. Since P2Y2 and KCa3.1 are co-expressed in primary tumors, our findings suggest that they may play a role in cancer progression.
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Affiliation(s)
- L Robles-Martínez
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Juriquilla Querétaro, CP 76230, Querétaro, México, Mexico
| | - E Garay
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Juriquilla Querétaro, CP 76230, Querétaro, México, Mexico
| | - M G Martel-Gallegos
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Juriquilla Querétaro, CP 76230, Querétaro, México, Mexico
| | - A Cisneros-Mejorado
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Juriquilla Querétaro, CP 76230, Querétaro, México, Mexico
| | - D Pérez-Montiel
- Departamento de Patología, Instituto Nacional de Cancerología, Secretaría de Salud, Av. San Fernando #22, Colonia Sección XVI, Tlalpan, CP 14080, Ciudad de México, México, Mexico
| | - A Lara
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Juriquilla Querétaro, CP 76230, Querétaro, México, Mexico
| | - R O Arellano
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Boulevard Juriquilla 3001, Juriquilla Querétaro, CP 76230, Querétaro, México, Mexico.
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27
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Rivolta I, Binda A, Molteni L, Rizzi L, Bresciani E, Possenti R, Fehrentz JA, Verdié P, Martinez J, Omeljaniuk RJ, Locatelli V, Torsello A. JMV5656, A Novel Derivative of TLQP-21, Triggers the Activation of a Calcium-Dependent Potassium Outward Current in Microglial Cells. Front Cell Neurosci 2017; 11:41. [PMID: 28280458 PMCID: PMC5322282 DOI: 10.3389/fncel.2017.00041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 02/08/2017] [Indexed: 01/13/2023] Open
Abstract
TLQP-21 (TLQPPASSRRRHFHHALPPAR) is a multifunctional peptide that is involved in the control of physiological functions, including feeding, reproduction, stress responsiveness, and general homeostasis. Despite the huge interest in TLQP-21 biological activity, very little is known about its intracellular mechanisms of action. In microglial cells, TLQP-21 stimulates increases of intracellular Ca2+ that may activate functions, including proliferation, migration, phagocytosis and production of inflammatory molecules. Our aim was to investigate whether JMV5656 (RRRHFHHALPPAR), a novel short analogue of TLQP-21, stimulates intracellular Ca2+ in the N9 microglia cells, and whether this Ca2+ elevation is coupled with the activation Ca2+-sensitive K+ channels. TLQP-21 and JMV5656 induced a sharp, dose-dependent increment in intracellular calcium. In 77% of cells, JMV5656 also caused an increase in the total outward currents, which was blunted by TEA (tetraethyl ammonium chloride), a non-selective blocker of voltage-dependent and Ca2+-activated potassium (K+) channels. Moreover, the effects of ion channel blockers charybdotoxin and iberiotoxin, suggested that multiple calcium-activated K+ channel types drove the outward current stimulated by JMV5656. Additionally, inhibition of JMV5656-stimulated outward currents by NS6180 (4-[[3-(trifluoromethyl)phenyl]methyl]-2H-1,4 benzothiazin-3(4H)-one) and TRAM-34 (triarylmethane-34), indicated that KCa3.1 channels are involved in this JMV5656 mechanisms of action. In summary, we demonstrate that, in N9 microglia cells, the interaction of JMV5656 with the TLQP-21 receptors induced an increase in intracellular Ca2+, and, following extracellular Ca2+ entry, the opening of KCa3.1 channels.
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Affiliation(s)
- Ilaria Rivolta
- Department of Medicine and Surgery, University of Milano-Bicocca Monza, Italy
| | - Anna Binda
- Department of Medicine and Surgery, University of Milano-Bicocca Monza, Italy
| | - Laura Molteni
- Department of Medicine and Surgery, University of Milano-Bicocca Monza, Italy
| | - Laura Rizzi
- Department of Medicine and Surgery, University of Milano-Bicocca Monza, Italy
| | - Elena Bresciani
- Department of Medicine and Surgery, University of Milano-Bicocca Monza, Italy
| | - Roberta Possenti
- Department of Medicine of Systems, University of Rome "Tor Vergata" Rome, Italy
| | - Jean-Alain Fehrentz
- CNRS, Institut des Biomolécules Max Mousseron UMR5247, École Nationale Supérieure de Chimie de Montpellier - University of Montpellier Montpellier, France
| | - Pascal Verdié
- CNRS, Institut des Biomolécules Max Mousseron UMR5247, École Nationale Supérieure de Chimie de Montpellier - University of Montpellier Montpellier, France
| | - Jean Martinez
- CNRS, Institut des Biomolécules Max Mousseron UMR5247, École Nationale Supérieure de Chimie de Montpellier - University of Montpellier Montpellier, France
| | | | - Vittorio Locatelli
- Department of Medicine and Surgery, University of Milano-Bicocca Monza, Italy
| | - Antonio Torsello
- Department of Medicine and Surgery, University of Milano-Bicocca Monza, Italy
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28
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Wei T, Yi M, Gu W, Hou L, Lu Q, Yu Z, Chen H. The Potassium Channel KCa3.1 Represents a Valid Pharmacological Target for Astrogliosis-Induced Neuronal Impairment in a Mouse Model of Alzheimer's Disease. Front Pharmacol 2017; 7:528. [PMID: 28105015 PMCID: PMC5214707 DOI: 10.3389/fphar.2016.00528] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 12/20/2016] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by progressive decline of cognitive function. Astrogliosis plays a critical role in AD by instigating neuroinflammation, which leads ultimately to cognition decline. We previously showed that the intermediate-conductance Ca2+-activated potassium channel (KCa3.1) is involved in astrogliosis-induced by TGF-β in vitro. In the present study, we investigated the contribution of KCa3.1 channels to astrogliosis-mediated neuroinflammation, using TgAPP/PS1 mice as a model for AD. We found that KCa3.1 expression was increased in reactive astrocytes as well as in neurons in the brains of both TgAPP/PS1 mice and AD patients. Pharmacological blockade of KCa3.1 significantly reduced astrogliosis, microglial activation, neuronal loss, and memory deficits. KCa3.1 blockade inhibited astrocyte activation and reduced brain levels of IL-1β, TNF-α, iNOS, and COX-2. Furthermore, we used primary co-cultures of cortical neurons and astrocytes to demonstrate an important role for KCa3.1 in the process of astrogliosis-induced neuroinflammatory responses during amyloid-β (Aβ)-induced neuronal loss. KCa3.1 was found to be involved in the Aβ-induced activated biochemical profile of reactive astrocytes, which included activation of JNK MAPK and production of reactive oxygen species. Pharmacological blockade of KCa3.1 attenuated Aβ-induced reactive astrocytes and indirect, astrogliosis-mediated damage to neurons. Our data clearly indicate a role for astrogliosis in AD pathogenesis and suggest that KCa3.1 inhibition might represent a good therapeutic target for the treatment of AD. Highlights: (1) Blockade of KCa3.1 in APP/PS1 transgenic mice attenuated astrogliosis and neuron loss, and an attenuation of memory deficits. (2) Blockade of KCa3.1 attenuated Aβ-induced indirect, astrogliosis-mediated damage to neurons in vitro via activation of JNK and ROS.
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Affiliation(s)
- Tianjiao Wei
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine Shanghai, China
| | - Mengni Yi
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine Shanghai, China
| | - Wen Gu
- Department of Respiratory Medicine, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine Shanghai, China
| | - Lina Hou
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine Shanghai, China
| | - Qin Lu
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine Shanghai, China
| | - Zhihua Yu
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine Shanghai, China
| | - Hongzhuan Chen
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine Shanghai, China
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29
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Chen M, Li J, Jiang F, Fu J, Xia X, Du J, Hu M, Huang J, Shen B. Orai1 forms a signal complex with BKCa channel in mesenteric artery smooth muscle cells. Physiol Rep 2016; 4:4/1/e12682. [PMID: 26755740 PMCID: PMC4760400 DOI: 10.14814/phy2.12682] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Orai1, a specific nonvoltage‐gated Ca2+ channel, has been found to be one of key molecules involved in store‐operated Ca2+ entry (SOCE). Orai1 may associate with other proteins to form a signaling complex, which is essential for regulating a variety of physiological functions. In this study, we studied the possible interaction between Orai1 and large conductance Ca2+‐activated potassium channel (BKCa). Using RNA interference technique, we demonstrated that the SOCE and its associated membrane hyperpolarization were markedly suppressed after knockdown of Orai1 with a specific Orai1 siRNA in rat mesenteric artery smooth muscle. Moreover, isometric tension measurements showed that agonist‐induced vasocontraction was increased after Orai1 was knocked down or the tissue was incubated with BKCa blocker iberiotoxin. Coimmunoprecipitation data revealed that BKCa and Orai1 could reciprocally pull down each other. In situ proximity ligation assay further demonstrated that Orai1 and BKCa are in close proximity. Taken together, these results indicate that Orai1 physically associates with BKCa to form a signaling complex in the rat mesenteric artery smooth muscle. Ca2+ influx via Orai1 stimulates BKCa, leading to membrane hyperpolarization. This hyperpolarizing effect of Orai1‐BKCa coupling could contribute to reduce agonist‐induced membrane depolarization, therefore preventing excessive contraction of the rat mesenteric artery smooth muscle in response to contractile agonists.
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Affiliation(s)
- Meihua Chen
- Department of Physiology, Anhui Medical University, Hefei, Anhui, China
| | - Jie Li
- Department of Physiology, Anhui Medical University, Hefei, Anhui, China
| | - Feifei Jiang
- Department of Pediatrics, The people's hospital of Bozhou, Bozhou, Anhui, China
| | - Jie Fu
- Department of Physiology, Anhui Medical University, Hefei, Anhui, China
| | - Xianming Xia
- Department of Gastroenterology and Hepatology, The Fourth Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China
| | - Juan Du
- Department of Physiology, Anhui Medical University, Hefei, Anhui, China
| | - Min Hu
- Department of Sports and Health, Guangdong Provincial Key Laboratory of Sports and Health Promotion, Guangzhou Sport University, Guangzhou, Guangdong, China
| | - Junhao Huang
- Department of Sports and Health, Guangdong Provincial Key Laboratory of Sports and Health Promotion, Guangzhou Sport University, Guangzhou, Guangdong, China
| | - Bing Shen
- Department of Physiology, Anhui Medical University, Hefei, Anhui, China Central Laboratory of Molecular and Cellular Biology of School of Basic Medicine, Anhui Medical University, Hefei, Anhui, China
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30
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Yi M, Yu P, Lu Q, Geller HM, Yu Z, Chen H. KCa3.1 constitutes a pharmacological target for astrogliosis associated with Alzheimer's disease. Mol Cell Neurosci 2016; 76:21-32. [PMID: 27567685 DOI: 10.1016/j.mcn.2016.08.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 07/28/2016] [Accepted: 08/23/2016] [Indexed: 01/08/2023] Open
Abstract
Alzheimer's disease (AD) is the most common type of dementia and is characterized by a progression from decline of episodic memory to a global impairment of cognitive function. Astrogliosis is a hallmark feature of AD, and reactive gliosis has been considered as an important target for intervention in various neurological disorders. We previously found in astrocyte cultures that the expression of the intermediate conductance calcium-activated potassium channel KCa3.1 was increased in reactive astrocytes induced by TGF-β, while pharmacological blockade or genetic deletion of KCa3.1 attenuated astrogliosis. In this study, we sought to suppress reactive gliosis in the context of AD by inhibiting KCa3.1 and evaluate its effects on the cognitive impairment using murine animal models such as the senescence-accelerated mouse prone 8 (SAMP8) model that exhibits some AD-like symptoms. We found KCa3.1 expression was increased in reactive astrocytes as well as neurons in the brains of both SAMP8 mice and Alzheimer's disease patients. Blockade of KCa3.1 with the selective inhibitor TRAM-34 in SAMP8 mice resulted in a decrease in astrogliosis as well as microglia activation, and moreover an attenuation of memory deficits. Using KCa3.1 knockout mice, we further confirmed that deletion of KCa3.1 reduced the activation of astrocytes and microglia, and rescued the memory loss induced by intrahippocampal Aβ1-42 peptide injection. We also found in astrocyte cultures that blockade of KCa3.1 or deletion of KCa3.1 suppressed Aβ oligomer-induced astrogliosis. Our data suggest that KCa3.1 inhibition might represent a promising therapeutic strategy for AD treatment.
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Affiliation(s)
- Mengni Yi
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Panpan Yu
- Guangdong-Hongkong-Macau Institute of CNS Regeneration; Ministry of Education Joint International Research Laboratory of CNS Regeneration, Jinan University, Guangzhou 510632, China
| | - Qin Lu
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Herbert M Geller
- Developmental Neurobiology Section, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zhihua Yu
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
| | - Hongzhuan Chen
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
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31
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Membrane coordination of receptors and channels mediating the inhibition of neuronal ion currents by ADP. Purinergic Signal 2016; 12:497-507. [PMID: 27172914 PMCID: PMC5023631 DOI: 10.1007/s11302-016-9516-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 05/02/2016] [Indexed: 12/29/2022] Open
Abstract
ADP and other nucleotides control ion currents in the nervous system via various P2Y receptors. In this respect, Cav2 and Kv7 channels have been investigated most frequently. The fine tuning of neuronal ion channel gating via G protein coupled receptors frequently relies on the formation of higher order protein complexes that are organized by scaffolding proteins and harbor receptors and channels together with interposed signaling components. However, ion channel complexes containing P2Y receptors have not been described. Therefore, the regulation of Cav2.2 and Kv7.2/7.3 channels via P2Y1 and P2Y12 receptors and the coordination of these ion channels and receptors in the plasma membranes of tsA 201 cells have been investigated here. ADP inhibited currents through Cav2.2 channels via both P2Y1 and P2Y12 receptors with phospholipase C and pertussis toxin-sensitive G proteins being involved, respectively. The nucleotide controlled the gating of Kv7 channels only via P2Y1 and phospholipase C. In fluorescence energy transfer assays using conventional as well as total internal reflection (TIRF) microscopy, both P2Y1 and P2Y12 receptors were found juxtaposed to Cav2.2 channels, but only P2Y1, and not P2Y12, was in close proximity to Kv7 channels. Using fluorescence recovery after photobleaching in TIRF microscopy, evidence for a physical interaction was obtained for the pair P2Y12/Cav2.2, but not for any other receptor/channel combination. These results reveal a membrane juxtaposition of P2Y receptors and ion channels in parallel with the control of neuronal ion currents by ADP. This juxtaposition may even result in apparent physical interactions between receptors and channels.
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Dale E, Staal RGW, Eder C, Möller T. KCa 3.1-a microglial target ready for drug repurposing? Glia 2016; 64:1733-41. [PMID: 27121595 DOI: 10.1002/glia.22992] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 03/29/2016] [Accepted: 04/03/2016] [Indexed: 01/25/2023]
Abstract
Over the past decade, glial cells have attracted attention for harboring unexploited targets for drug discovery. Several glial targets have attracted de novo drug discovery programs, as highlighted in this GLIA Special Issue. Drug repurposing, which has the objective of utilizing existing drugs as well as abandoned, failed, or not yet pursued clinical development candidates for new indications, might provide a faster opportunity to bring drugs for glial targets to patients with unmet needs. Here, we review the potential of the intermediate-conductance calcium-activated potassium channels KCa 3.1 as the target for such a repurposing effort. We discuss the data on KCa 3.1 expression on microglia in vitro and in vivo and review the relevant literature on the two KCa 3.1 inhibitors TRAM-34 and Senicapoc. Finally, we provide an outlook of what it might take to harness the potential of KCa 3.1 as a bona fide microglial drug target. GLIA 2016;64:1733-1741.
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Affiliation(s)
- Elena Dale
- Neuroinflammation Disease Biology Unit, Lundbeck Research USA, Paramus, New Jersey
| | - Roland G W Staal
- Neuroinflammation Disease Biology Unit, Lundbeck Research USA, Paramus, New Jersey
| | - Claudia Eder
- Institute for Infection and Immunity, St. George's, University of London, United Kingdom
| | - Thomas Möller
- Neuroinflammation Disease Biology Unit, Lundbeck Research USA, Paramus, New Jersey
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Grimaldi A, D'Alessandro G, Golia MT, Grössinger EM, Di Angelantonio S, Ragozzino D, Santoro A, Esposito V, Wulff H, Catalano M, Limatola C. KCa3.1 inhibition switches the phenotype of glioma-infiltrating microglia/macrophages. Cell Death Dis 2016; 7:e2174. [PMID: 27054329 PMCID: PMC4855657 DOI: 10.1038/cddis.2016.73] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 02/22/2016] [Accepted: 03/02/2016] [Indexed: 12/11/2022]
Abstract
Among the strategies adopted by glioma to successfully invade the brain parenchyma is turning the infiltrating microglia/macrophages (M/MΦ) into allies, by shifting them toward an anti-inflammatory, pro-tumor phenotype. Both glioma and infiltrating M/MΦ cells express the Ca2+-activated K+ channel (KCa3.1), and the inhibition of KCa3.1 activity on glioma cells reduces tumor infiltration in the healthy brain parenchyma. We wondered whether KCa3.1 inhibition could prevent the acquisition of a pro-tumor phenotype by M/MΦ cells, thus contributing to reduce glioma development. With this aim, we studied microglia cultured in glioma-conditioned medium or treated with IL-4, as well as M/MΦ cells acutely isolated from glioma-bearing mice and from human glioma biopsies. Under these different conditions, M/MΦ were always polarized toward an anti-inflammatory state, and preventing KCa3.1 activation by 1-[(2-Chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM-34), we observed a switch toward a pro-inflammatory, antitumor phenotype. We identified FAK and PI3K/AKT as the molecular mechanisms involved in this phenotype switch, activated in sequence after KCa3.1. Anti-inflammatory M/MΦ have higher expression levels of KCa3.1 mRNA (kcnn4) that are reduced by KCa3.1 inhibition. In line with these findings, TRAM-34 treatment, in vivo, significantly reduced the size of tumors in glioma-bearing mice. Our data indicate that KCa3.1 channels are involved in the inhibitory effects exerted by the glioma microenvironment on infiltrating M/MΦ, suggesting a possible role as therapeutic targets in glioma.
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Affiliation(s)
- A Grimaldi
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome 00185, Italy
| | - G D'Alessandro
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome 00185, Italy.,IRCCS Neuromed, Via Atinense 18, Pozzilli 86077, Italy
| | - M T Golia
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome 00185, Italy
| | - E M Grössinger
- Department of Pharmacology, University of California, 451 Health Sciences Drive, GBSF3502, Davis, CA 95616, USA
| | - S Di Angelantonio
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome 00185, Italy.,Center for Life Nanoscience Istituto Italiano di Tecnologia@Sapienza, Rome, Italy
| | - D Ragozzino
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome 00185, Italy.,IRCCS Neuromed, Via Atinense 18, Pozzilli 86077, Italy
| | - A Santoro
- Department of Neurology and Psychiatry, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome 00185, Italy
| | - V Esposito
- IRCCS Neuromed, Via Atinense 18, Pozzilli 86077, Italy.,Department of Neurology and Psychiatry, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome 00185, Italy
| | - H Wulff
- Department of Pharmacology, University of California, 451 Health Sciences Drive, GBSF3502, Davis, CA 95616, USA
| | - M Catalano
- Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome 00185, Italy.,IRCCS Neuromed, Via Atinense 18, Pozzilli 86077, Italy
| | - C Limatola
- IRCCS Neuromed, Via Atinense 18, Pozzilli 86077, Italy.,Pasteur Institute-Department of Physiology and Pharmacology, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome 00185, Italy
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34
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Siddiqui TA, Lively S, Schlichter LC. Complex molecular and functional outcomes of single versus sequential cytokine stimulation of rat microglia. J Neuroinflammation 2016; 13:66. [PMID: 27009332 PMCID: PMC4806433 DOI: 10.1186/s12974-016-0531-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 03/16/2016] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Microglia are the "professional" phagocytes of the CNS. Phagocytosis is crucial for normal CNS development and maintenance, but it can be either beneficial or detrimental after injury or disease. For instance, white matter damage releases myelin debris that must be cleared by microglia in order for re-myelination to occur. However, phagocytosis can also produce damaging reactive oxygen species (ROS). Furthermore, microglia can acquire pro-inflammatory (M1) or anti-inflammatory (M2) activation states that affect cell functions. Although microglia are exposed to a changing cytokine environment after injury or disease, little is known about the molecular and functional consequences. Therefore, we applied several microglial activation paradigms, with or without myelin debris. We assessed (i) gene expression changes reflecting microglial activation and inflammatory states, and receptors and enzymes related to phagocytosis and ROS production, (ii) myelin phagocytosis and production of ROS, and (iii) expression and contributions of several ion channels that are considered potential targets for regulating microglial behavior. METHODS Primary rat microglia were exposed to cytokines, individually or sequentially. First, responses to individual M1 or M2 stimuli were compared: IFN-γ plus TNF-α ("I + T"; M1 activation), interleukin-4 (M2a/alternative activation), and interleukin-10 (M2c/acquired deactivation). Second, sequential cytokine addition was used to assess microglia repolarization and cell functions. The paradigms were M2a→M1, M2c→M1, M1→M2a, and M1→M2c. RESULTS M1 stimulation increased pro-inflammatory genes, phagocytosis, and ROS, as well as expression of Kv1.3, KCa3.1, and Kir2.1 channels. M2a stimulation increased anti-inflammatory genes, ROS production, and Kv1.3 and KCa3.1 expression. Myelin phagocytosis enhanced the M1 profile and dampened the M2a profile, and both phagocytosis and ROS production were dependent on NOX enzymes and Kir2.1 and CRAC channels. Importantly, microglia showed some capacity for re-polarization between M1 and M2a states, based on gene expression changes, myelin phagocytosis, and ROS production. CONCLUSIONS In response to polarizing and re-polarizing cytokine treatments, microglia display complex changes in gene transcription profiles, phagocytic capacity, NOX-mediated ROS production, and in ion channels involved in microglial activation. Because these changes might affect microglia-mediated CNS inflammation, they should be considered in future experimental, pre-clinical studies.
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Affiliation(s)
- Tamjeed A Siddiqui
- Genes and Development Division, Krembil Research Institute, University Health Network, Toronto, Ontario, M5T 2S8, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Starlee Lively
- Genes and Development Division, Krembil Research Institute, University Health Network, Toronto, Ontario, M5T 2S8, Canada
| | - Lyanne C Schlichter
- Genes and Development Division, Krembil Research Institute, University Health Network, Toronto, Ontario, M5T 2S8, Canada. .,Department of Physiology, University of Toronto, Toronto, Ontario, Canada. .,Krembil Discovery Tower, Krembil Research Institute, Room 7KD-417, 60 Leonard Street, Toronto, Ontario, M5T 2S8, Canada.
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35
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Penna A, Stutzin A. KCa3.1-Dependent Hyperpolarization Enhances Intracellular Ca2+ Signaling Induced by fMLF in Differentiated U937 Cells. PLoS One 2015; 10:e0139243. [PMID: 26418693 PMCID: PMC4587941 DOI: 10.1371/journal.pone.0139243] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 09/10/2015] [Indexed: 12/29/2022] Open
Abstract
Formylated peptides are chemotactic agents generated by pathogens. The most relevant peptide is fMLF (formyl-Met-Leu-Phe) which participates in several immune functions, such as chemotaxis, phagocytosis, cytokine release and generation of reactive oxygen species. In macrophages fMLF-dependent responses are dependent on both, an increase in intracellular calcium concentration and on a hyperpolarization of the membrane potential. However, the molecular entity underlying this hyperpolarization remains unknown and it is not clear whether changes in membrane potential are linked to the increase in intracellular Ca2+. In this study, differentiated U937 cells, as a macrophage-like cell model, was used to characterize the fMLF response using electrophysiological and Ca2+ imaging techniques. We demonstrate by means of pharmacological and molecular biology tools that fMLF induces a Ca2+-dependent hyperpolarization via activation of the K+ channel KCa3.1 and thus, enhancing fMLF-induced intracellular Ca2+ increase through an amplification of the driving force for Ca2+ entry. Consequently, enhanced Ca2+ influx would in turn lengthen the hyperpolarization, operating as a positive feedback mechanism for fMLF-induced Ca2+ signaling.
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Affiliation(s)
- Antonello Penna
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Independencia 838–0453, Santiago, Chile
| | - Andrés Stutzin
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Independencia 838–0453, Santiago, Chile
- * E-mail:
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36
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Lam D, Schlichter LC. Expression and contributions of the Kir2.1 inward-rectifier K(+) channel to proliferation, migration and chemotaxis of microglia in unstimulated and anti-inflammatory states. Front Cell Neurosci 2015; 9:185. [PMID: 26029054 PMCID: PMC4428136 DOI: 10.3389/fncel.2015.00185] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 04/28/2015] [Indexed: 12/14/2022] Open
Abstract
When microglia respond to CNS damage, they can range from pro-inflammatory (classical, M1) to anti-inflammatory, alternative (M2) and acquired deactivation states. It is important to determine how microglial functions are affected by these activation states, and to identify molecules that regulate their behavior. Microglial proliferation and migration are crucial during development and following damage in the adult, and both functions are Ca2+-dependent. In many cell types, the membrane potential and driving force for Ca2+ influx are regulated by inward-rectifier K+ channels, including Kir2.1, which is prevalent in microglia. However, it is not known whether Kir2.1 expression and contributions are altered in anti-inflammatory states. We tested the hypothesis that Kir2.1 contributes to Ca2+ entry, proliferation and migration of rat microglia. Kir2.1 (KCNJ2) transcript expression, current amplitude, and proliferation were comparable in unstimulated microglia and following alternative activation (IL-4 stimulated) and acquired deactivation (IL-10 stimulated). To examine functional roles of Kir2.1 in microglia, we first determined that ML133 was more effective than the commonly used blocker, Ba2+; i.e., ML133 was potent (IC50 = 3.5 μM) and voltage independent. Both blockers slightly increased proliferation in unstimulated or IL-4 (but not IL-10)-stimulated microglia. Stimulation with IL-4 or IL-10 increased migration and ATP-induced chemotaxis, and blocking Kir2.1 greatly reduced both but ML133 was more effective. In all three activation states, blocking Kir2.1 with ML133 dramatically reduced Ca2+ influx through Ca2+-release-activated Ca2+ (CRAC) channels. Thus, Kir2.1 channel activity is necessary for microglial Ca2+ signaling and migration under resting and anti-inflammatory states but the channel weakly inhibits proliferation.
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Affiliation(s)
- Doris Lam
- Genetics and Development Division, Toronto Western Research Institute, University Health Network Toronto, ON, Canada ; Department of Physiology, University of Toronto Toronto, ON, Canada
| | - Lyanne C Schlichter
- Genetics and Development Division, Toronto Western Research Institute, University Health Network Toronto, ON, Canada ; Department of Physiology, University of Toronto Toronto, ON, Canada
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37
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Ferreira R, Wong R, Schlichter LC. KCa3.1/IK1 Channel Regulation by cGMP-Dependent Protein Kinase (PKG) via Reactive Oxygen Species and CaMKII in Microglia: An Immune Modulating Feedback System? Front Immunol 2015; 6:153. [PMID: 25904916 PMCID: PMC4389654 DOI: 10.3389/fimmu.2015.00153] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 03/23/2015] [Indexed: 01/09/2023] Open
Abstract
The intermediate conductance Ca2+-activated K+ channel, KCa3.1 (IK1/SK4/KCNN4) is widely expressed in the innate and adaptive immune system. KCa3.1 contributes to proliferation of activated T lymphocytes, and in CNS-resident microglia, it contributes to Ca2+ signaling, migration, and production of pro-inflammatory mediators (e.g., reactive oxygen species, ROS). KCa3.1 is under investigation as a therapeutic target for CNS disorders that involve microglial activation and T cells. However, KCa3.1 is post-translationally regulated, and this will determine when and how much it can contribute to cell functions. We previously found that KCa3.1 trafficking and gating require calmodulin (CaM) binding, and this is inhibited by cAMP kinase (PKA) acting at a single phosphorylation site. The same site is potentially phosphorylated by cGMP kinase (PKG), and in some cells, PKG can increase Ca2+, CaM activation, and ROS. Here, we addressed KCa3.1 regulation through PKG-dependent pathways in primary rat microglia and the MLS-9 microglia cell line, using perforated-patch recordings to preserve intracellular signaling. Elevating cGMP increased both the KCa3.1 current and intracellular ROS production, and both were prevented by the selective PKG inhibitor, KT5823. The cGMP/PKG-evoked increase in KCa3.1 current in intact MLS-9 microglia was mediated by ROS, mimicked by applying hydrogen peroxide (H2O2), inhibited by a ROS scavenger (MGP), and prevented by a selective CaMKII inhibitor (mAIP). Similar results were seen in alternative-activated primary rat microglia; their KCa3.1 current required PKG, ROS, and CaMKII, and they had increased ROS production that required KCa3.1 activity. The increase in current apparently did not result from direct effects on the channel open probability (Po) or Ca2+ dependence because, in inside-out patches from transfected HEK293 cells, single-channel activity was not affected by cGMP, PKG, H2O2 at normal or elevated intracellular Ca2+. The regulation pathway we have identified in intact microglia and MLS-9 cells is expected to have broad implications because KCa3.1 plays important roles in numerous cells and tissues.
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Affiliation(s)
- Roger Ferreira
- Genetics and Development Division, Toronto Western Research Institute, University Health Network , Toronto, ON , Canada ; Department of Physiology, University of Toronto , Toronto, ON , Canada
| | - Raymond Wong
- Genetics and Development Division, Toronto Western Research Institute, University Health Network , Toronto, ON , Canada ; Department of Physiology, University of Toronto , Toronto, ON , Canada
| | - Lyanne C Schlichter
- Genetics and Development Division, Toronto Western Research Institute, University Health Network , Toronto, ON , Canada ; Department of Physiology, University of Toronto , Toronto, ON , Canada
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38
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Huang C, Lu X, Wang J, Tong L, Jiang B, Zhang W. Inhibition of endogenous heat shock protein 70 attenuates inducible nitric oxide synthase induction via disruption of heat shock protein 70/Na(+) /H(+) exchanger 1-Ca(2+) -calcium-calmodulin-dependent protein kinase II/transforming growth factor β-activated kinase 1-nuclear factor-κB signals in BV-2 microglia. J Neurosci Res 2015; 93:1192-202. [PMID: 25691123 DOI: 10.1002/jnr.23571] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 12/24/2014] [Accepted: 01/08/2015] [Indexed: 12/16/2022]
Abstract
Inducible nitric oxide synthase (iNOS) critically contributes to inflammation and host defense. The inhibition of heat shock protein 70 (Hsp70) prevents iNOS induction in lipopolysaccharide (LPS)-stimulated macrophages. However, the role and mechanism of endogenous Hsp70 in iNOS induction in microglia remains unclear. This study addresses this issue in BV-2 microglia, showing that Hsp70 inhibition or knockdown prevents LPS-induced iNOS protein expression and nitric oxide production. Real-time PCR experiments showed that LPS-induced iNOS mRNA transcription was blocked by Hsp70 inhibition. Further studies revealed that the inhibition of Hsp70 attenuated LPS-stimulated nuclear translocation and phosphorylation of nuclear factor (NF)-κB as well as the degradation of inhibitor of κB (IκB)-α and phosphorylation of IκB kinase β (IKKβ). This prevention effect of Hsp70 inhibition on IKKβ-NF-κB activation was found to be dependent on the Ca(2+) /calcium-calmodulin-dependent protein kinase II (CaMKII)/transforming growth factor β-activated kinase 1 (TAK1) signals based on the following observations: 1) chelation of intracellular Ca(2+) or inhibition of CaMKII reduced LPS-induced increases in TAK1 phosphorylation and 2) Hsp70 inhibition reduced LPS-induced increases in CaMKII/TAK1 phosphorylation, intracellular pH value, [Ca(2+) ]i , and CaMKII/TAK1 association. Mechanistic studies showed that Hsp70 inhibition disrupted the association between Hsp70 and Na(+) /H(+) exchanger 1 (NHE1), which is an important exchanger responsible for Ca(2+) influx in LPS-stimulated cells. These studies demonstrate that the inhibition of endogenous Hsp70 attenuates the induction of iNOS, which likely occurs through the disruption of NHE1/Hsp70-Ca(2+) -CaMKII/TAK1-NF-κB signals in BV-2 microglia, providing further insight into the functions of Hsp70 in the CNS.
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Affiliation(s)
- Chao Huang
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, Jiangsu, People's Republic of China
| | - Xu Lu
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, Jiangsu, People's Republic of China
| | - Jia Wang
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, Jiangsu, People's Republic of China
| | - Lijuan Tong
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, Jiangsu, People's Republic of China
| | - Bo Jiang
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, Jiangsu, People's Republic of China
| | - Wei Zhang
- Department of Pharmacology, School of Medicine, Nantong University, Nantong, Jiangsu, People's Republic of China
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Inhibition of KCa3.1 by depolarisation and 2-aminoethoxydiphenyl borate (2-APB) during Ca2+ release activated Ca2+ (CRAC) entry in human erythroleukemia (HEL) cells: Implications for the interpretation of 2-APB inhibition of CRAC entry. Cell Calcium 2015; 57:76-88. [DOI: 10.1016/j.ceca.2014.12.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 11/12/2014] [Accepted: 12/12/2014] [Indexed: 01/05/2023]
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40
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PKA reduces the rat and human KCa3.1 current, CaM binding, and Ca2+ signaling, which requires Ser332/334 in the CaM-binding C terminus. J Neurosci 2015; 34:13371-83. [PMID: 25274816 DOI: 10.1523/jneurosci.1008-14.2014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The Ca(2+)-dependent K(+) channel, KCa3.1 (KCNN4/IK/SK4), is widely expressed and contributes to cell functions that include volume regulation, migration, membrane potential, and excitability. KCa3.1 is now considered a therapeutic target for several diseases, including CNS disorders involving microglial activation; thus, we need to understand how KCa3.1 function is regulated. KCa3.1 gating and trafficking require calmodulin binding to the two ends of the CaM-binding domain (CaMBD), which also contains three conserved sites for Ser/Thr kinases. Although cAMP protein kinase (PKA) signaling is important in many cells that use KCa3.1, reports of channel regulation by PKA are inconsistent. We first compared regulation by PKA of native rat KCa3.1 channels in microglia (and the microglia cell line, MLS-9) with human KCa3.1 expressed in HEK293 cells. In all three cells, PKA activation with Sp-8-Br-cAMPS decreased the current, and this was prevented by the PKA inhibitor, PKI14-22. Inhibiting PKA with Rp-8-Br-cAMPS increased the current in microglia. Mutating the single PKA site (S334A) in human KCa3.1 abolished the PKA-dependent regulation. CaM-affinity chromatography showed that CaM binding to KCa3.1 was decreased by PKA-dependent phosphorylation of S334, and this regulation was absent in the S334A mutant. Single-channel analysis showed that PKA decreased the open probability in wild-type but not S334A mutant channels. The same decrease in current for native and wild-type expressed KCa3.1 channels (but not S334A) occurred when PKA was activated through the adenosine A2a receptor. Finally, by decreasing the KCa3.1 current, PKA activation reduced Ca(2+)-release-activated Ca(2+) entry following activation of metabotropic purinergic receptors in microglia.
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41
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Langfelder A, Okonji E, Deca D, Wei WC, Glitsch MD. Extracellular acidosis impairs P2Y receptor-mediated Ca(2+) signalling and migration of microglia. Cell Calcium 2015; 57:247-56. [PMID: 25623949 DOI: 10.1016/j.ceca.2015.01.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 12/31/2014] [Accepted: 01/02/2015] [Indexed: 02/07/2023]
Abstract
Microglia are the resident macrophage and immune cell of the brain and are critically involved in combating disease and assaults on the brain. Virtually all brain pathologies are accompanied by acidosis of the interstitial fluid, meaning that microglia are exposed to an acidic environment. However, little is known about how extracellular acidosis impacts on microglial function. The activity of microglia is tightly controlled by 'on' and 'off' signals, the presence or absence of which results in generation of distinct phenotypes in microglia. Activation of G protein coupled purinergic (P2Y) receptors triggers a number of distinct behaviours in microglia, including activation, migration, and phagocytosis. Using pharmacological tools and fluorescence imaging of the murine cerebellar microglia cell line C8B4, we show that extracellular acidosis interferes with P2Y receptor-mediated Ca(2+) signalling in these cells. Distinct P2Y receptors give rise to signature intracellular Ca(2+) signals, and Ca(2+) release from stores and Ca(2+) influx are differentially affected by acidotic conditions: Ca(2+) release is virtually unaffected, whereas Ca(2+) influx, mediated at least in part by store-operated Ca(2+) channels, is profoundly inhibited. Furthermore, P2Y1 and P2Y6-mediated stimulation of migration is inhibited under conditions of extracellular acidosis, whereas basal migration independent of P2Y receptor activation is not. Taken together, our results demonstrate that an acidic microenvironment impacts on P2Y receptor-mediated Ca(2+) signalling, thereby influencing microglial responses and responsiveness to extracellular signals. This may result in altered behaviour of microglia under pathological conditions compared with microglial responses in healthy tissue.
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Affiliation(s)
- Antonia Langfelder
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Emeka Okonji
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Diana Deca
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Wei-Chun Wei
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, UK
| | - Maike D Glitsch
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, UK.
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Siddiqui T, Lively S, Ferreira R, Wong R, Schlichter LC. Expression and contributions of TRPM7 and KCa2.3/SK3 channels to the increased migration and invasion of microglia in anti-inflammatory activation states. PLoS One 2014; 9:e106087. [PMID: 25148577 PMCID: PMC4141841 DOI: 10.1371/journal.pone.0106087] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 07/31/2014] [Indexed: 01/17/2023] Open
Abstract
Microglia rapidly respond to CNS injury and disease and can assume a spectrum of activation states. While changes in gene expression and production of inflammatory mediators have been extensively described after classical (LPS-induced) and alternative (IL4-induced) microglial activation, less is known about acquired de-activation in response to IL10. It is important to understand how microglial activation states affect their migration and invasion; crucial functions after injury and in the developing CNS. We reported that LPS-treated rat microglia migrate very poorly, while IL4-treated cells migrate and invade much better. Having discovered that the lamellum of migrating microglia contains a large ring of podosomes – microscopic structures that are thought to mediate adhesion, migration and invasion – we hypothesized that IL4 and IL10 would differentially affect podosome expression, gene induction, migration and invasion. Further, based on the enrichment of the KCa2.3/SK3 Ca2+-activated potassium channel in microglial podosomes, we predicted that it regulates migration and invasion. We found both similarities and differences in gene induction by IL4 and IL10 and, while both cytokines increased migration and invasion, only IL10 affected podosome expression. KCa2.3 currents were recorded in microglia under all three activation conditions and KCNN3 (KCa2.3) expression was similar. Surprisingly then, of three KCa2.3 inhibitors (apamin, tamapin, NS8593), only NS8593 abrogated the increased migration and invasion of IL4 and IL10-treated microglia (and invasion of unstimulated microglia). This discrepancy was explained by the observed block of TRPM7 currents in microglia by NS8593, which occurred under all three activation conditions. A similar inhibition of both migration and invasion was seen with a TRPM7 inhibitor (AA-861) that does not block KCa2.3 channels. Thus, we conclude that TRPM7 (not KCa2.3) contributes to the enhanced ability of microglia to migrate and invade when in anti-inflammatory states. This will be an important consideration in developing TRPM7 inhibitors for treating CNS injury.
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Affiliation(s)
- Tamjeed Siddiqui
- Toronto Western Research Institute, Genes and Development Division, University Health Network, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Starlee Lively
- Toronto Western Research Institute, Genes and Development Division, University Health Network, Toronto, Ontario, Canada
| | - Roger Ferreira
- Toronto Western Research Institute, Genes and Development Division, University Health Network, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Raymond Wong
- Toronto Western Research Institute, Genes and Development Division, University Health Network, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Lyanne C. Schlichter
- Toronto Western Research Institute, Genes and Development Division, University Health Network, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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Ferreira R, Lively S, Schlichter LC. IL-4 type 1 receptor signaling up-regulates KCNN4 expression, and increases the KCa3.1 current and its contribution to migration of alternative-activated microglia. Front Cell Neurosci 2014; 8:183. [PMID: 25071444 PMCID: PMC4077126 DOI: 10.3389/fncel.2014.00183] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 06/14/2014] [Indexed: 01/05/2023] Open
Abstract
The Ca2+-activated K+ channel, KCa3.1 (KCNN4/IK1/SK4), contributes to “classical,” pro-inflammatory activation of microglia, and KCa3.1 blockers have improved the outcome in several rodent models of CNS damage. For instance, blocking KCa3.1 with TRAM-34 rescued retinal ganglion neurons after optic nerve damage in vivo and, reduced p38 MAP kinase activation, production of reactive oxygen and nitrogen species, and neurotoxicity by microglia in vitro. In pursuing the therapeutic potential of KCa3.1 blockers, it is crucial to assess KCa3.1 contributions to other microglial functions and activation states, especially the IL-4-induced “alternative” activation state that can counteract pro-inflammatory states. We recently found that IL-4 increases microglia migration – a crucial function in the healthy and damaged CNS – and that KCa3.1 contributes to P2Y2 receptor-stimulated migration. Here, we discovered that KCa3.1 is greatly increased in alternative-activated rat microglia and then contributes to an enhanced migratory capacity. IL-4 up-regulated KCNN4 mRNA (by 6 h) and greatly increased the KCa3.1 current by 1 day, and this required de novo protein synthesis. The increase in current was sustained for at least 6 days. IL-4 increased microglial migration and this was reversed by blocking KCa3.1 with TRAM-34. A panel of inhibitors of signal-transduction mediators was used to analyze contributions of IL-4-related signaling pathways. Induction of KCNN4 mRNA and KCa3.1 current was mediated specifically through IL-4 binding to the type I receptor and, surprisingly, it required JAK3, Ras/MEK/ERK signaling and the transcription factor, activator protein-1, rather than JAK2, STAT6, or phosphatidylinositol 3-kinase.The same receptor subtype and pathway were required for the enhanced KCa3.1-dependent migration. In providing the first direct signaling link between an IL-4 receptor, expression and roles of an ion channel, this study also highlights the potential importance of KCa3.1 in alternative-activated microglia.
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Affiliation(s)
- Roger Ferreira
- Genes and Development Division, Toronto Western Research Institute, University Health Network Toronto, ON, Canada ; Department of Physiology, University of Toronto Toronto, ON, Canada
| | - Starlee Lively
- Genes and Development Division, Toronto Western Research Institute, University Health Network Toronto, ON, Canada
| | - Lyanne C Schlichter
- Genes and Development Division, Toronto Western Research Institute, University Health Network Toronto, ON, Canada ; Department of Physiology, University of Toronto Toronto, ON, Canada
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Lamarca A, Gella A, Martiañez T, Segura M, Figueiro-Silva J, Grijota-Martinez C, Trullas R, Casals N. Uridine 5'-triphosphate promotes in vitro Schwannoma cell migration through matrix metalloproteinase-2 activation. PLoS One 2014; 9:e98998. [PMID: 24905332 PMCID: PMC4048211 DOI: 10.1371/journal.pone.0098998] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 05/09/2014] [Indexed: 02/07/2023] Open
Abstract
In response to peripheral nerve injury, Schwann cells adopt a migratory phenotype and modify the extracellular matrix to make it permissive for cell migration and axonal re-growth. Uridine 5′-triphosphate (UTP) and other nucleotides are released during nerve injury and activate purinergic receptors expressed on the Schwann cell surface, but little is known about the involvement of purine signalling in wound healing. We studied the effect of UTP on Schwannoma cell migration and wound closure and the intracellular signaling pathways involved. We found that UTP treatment induced Schwannoma cell migration through activation of P2Y2 receptors and through the increase of extracellular matrix metalloproteinase-2 (MMP-2) activation and expression. Knockdown P2Y2 receptor or MMP-2 expression greatly reduced wound closure and MMP-2 activation induced by UTP. MMP-2 activation evoked by injury or UTP was also mediated by phosphorylation of all 3 major mitogen-activated protein kinases (MAPKs): JNK, ERK1/2, and p38. Inhibition of these MAPK pathways decreased both MMP-2 activation and cell migration. Interestingly, MAPK phosphorylation evoked by UTP exhibited a biphasic pattern, with an early transient phosphorylation 5 min after treatment, and a late and sustained phosphorylation that appeared at 6 h and lasted up to 24 h. Inhibition of MMP-2 activity selectively blocked the late, but not the transient, phase of MAPK activation. These results suggest that MMP-2 activation and late MAPK phosphorylation are part of a positive feedback mechanism to maintain the migratory phenotype for wound healing. In conclusion, our findings show that treatment with UTP stimulates in vitro Schwannoma cell migration and wound repair through a MMP-2-dependent mechanism via P2Y2 receptors and MAPK pathway activation.
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Affiliation(s)
- Aloa Lamarca
- Department of Basic Sciences, Facultat de Medicina, Universitat Internacional de Catalunya, Sant Cugat del Vallès, Spain
| | - Alejandro Gella
- Department of Basic Sciences, Facultat de Medicina, Universitat Internacional de Catalunya, Sant Cugat del Vallès, Spain
- * E-mail:
| | - Tania Martiañez
- Department of Basic Sciences, Facultat de Medicina, Universitat Internacional de Catalunya, Sant Cugat del Vallès, Spain
| | - Mònica Segura
- Department of Basic Sciences, Facultat de Medicina, Universitat Internacional de Catalunya, Sant Cugat del Vallès, Spain
| | - Joana Figueiro-Silva
- Neurobiology Unit, Institut d′Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas, Institut d′Investigacions Biomèdiques Pi i Sunyer, Barcelona, Spain
| | - Carmen Grijota-Martinez
- Department of Basic Sciences, Facultat de Medicina, Universitat Internacional de Catalunya, Sant Cugat del Vallès, Spain
| | - Ramón Trullas
- Neurobiology Unit, Institut d′Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas, Institut d′Investigacions Biomèdiques Pi i Sunyer, Barcelona, Spain
| | - Núria Casals
- Department of Basic Sciences, Facultat de Medicina, Universitat Internacional de Catalunya, Sant Cugat del Vallès, Spain
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y Nutrición (CIBERobn), Instituto de Salud Carlos III, Madrid, Spain
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Yu Z, Yu P, Chen H, Geller HM. Targeted inhibition of KCa3.1 attenuates TGF-β-induced reactive astrogliosis through the Smad2/3 signaling pathway. J Neurochem 2014; 130:41-49. [PMID: 24606313 DOI: 10.1111/jnc.12710] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 02/27/2014] [Accepted: 03/05/2014] [Indexed: 12/16/2022]
Abstract
Reactive astrogliosis, characterized by cellular hypertrophy and various alterations in gene expression and proliferative phenotypes, is considered to contribute to brain injuries and diseases as diverse as trauma, neurodegeneration, and ischemia. KCa3.1 (intermediate-conductance calcium-activated potassium channel), a potassium channel protein, has been reported to be up-regulated in reactive astrocytes after spinal cord injury in vivo. However, little is known regarding the exact role of KCa3.1 in reactive astrogliosis. To elucidate the role of KCa3.1 in regulating reactive astrogliosis, we investigated the effects of either blocking or knockout of KCa3.1 channels on the production of astrogliosis and astrocytic proliferation in response to transforming growth factor (TGF)-β in primary cultures of mouse astrocytes. We found that TGF-β increased KCa3.1 protein expression in astrocytes, with a concomitant marked increase in the expression of reactive astrogliosis, including glial fibrillary acidic protein and chondroitin sulfate proteoglycans. These changes were significantly attenuated by the KCa3.1 inhibitor 1-((2-chlorophenyl) (diphenyl)methyl)-1H-pyrazole (TRAM-34). Similarly, the increase in glial fibrillary acidic protein and chondroitin sulfate proteoglycans in response to TGF-β was attenuated in KCa3.1(-/-) astrocytes. TRAM-34 also suppressed astrocytic proliferation. In addition, the TGF-β-induced phosphorylation of Smad2 and Smad3 proteins was reduced with either inhibition of KCa3.1 with TRAM-34 or in KCa3.1(-/-) astrocytes. These findings highlight a novel role for the KCa3.1 channel in reactive astrogliosis phenotypic modulation and provide a potential target for therapeutic intervention for brain injuries. Reactive astrogliosis is characterized by the expression of glial fibrillary acidic protein and chondroitin sulfate proteoglycans. We demonstrate that either pharmacological blockade or knockout of KCa3.1 channels reduces reactive gliosis in cultured astrocytes caused by TGF-β, and also reduces TGF-β-induced phosphorylation of Smad2/3.
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Affiliation(s)
- Zhihua Yu
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Developmental Neurobiology Section, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Panpan Yu
- Developmental Neurobiology Section, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Hongzhuan Chen
- Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Herbert M Geller
- Developmental Neurobiology Section, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
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KCa and Ca(2+) channels: the complex thought. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:2322-33. [PMID: 24613282 DOI: 10.1016/j.bbamcr.2014.02.019] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 02/13/2014] [Accepted: 02/26/2014] [Indexed: 01/30/2023]
Abstract
Potassium channels belong to the largest and the most diverse super-families of ion channels. Among them, Ca(2+)-activated K(+) channels (KCa) comprise many members. Based on their single channel conductance they are divided into three subfamilies: big conductance (BKCa), intermediate conductance (IKCa) and small conductance (SKCa; SK1, SK2 and SK3). Ca(2+) channels are divided into two main families, voltage gated/voltage dependent Ca(2+) channels and non-voltage gated/voltage independent Ca(2+) channels. Based on their electrophysiological and pharmacological properties and on the tissue where there are expressed, voltage gated Ca(2+) channels (Cav) are divided into 5 families: T-type, L-type, N-type, P/Q-type and R-type Ca(2+). Non-voltage gated Ca(2+) channels comprise the TRP (TRPC, TRPV, TRPM, TRPA, TRPP, TRPML and TRPN) and Orai (Orai1 to Orai3) families and their partners STIM (STIM1 to STIM2). A depolarization is needed to activate voltage-gated Ca(2+) channels while non-voltage gated Ca(2+) channels are activated by Ca(2+) depletion of the endoplasmic reticulum stores (SOCs) or by receptors (ROCs). These two Ca(2+) channel families also control constitutive Ca(2+) entries. For reducing the energy consumption and for the fine regulation of Ca(2+), KCa and Ca(2+) channels appear associated as complexes in excitable and non-excitable cells. Interestingly, there is now evidence that KCa-Ca(2+) channel complexes are also found in cancer cells and contribute to cancer-associated functions such as cell proliferation, cell migration and the capacity to develop metastases. This article is part of a Special Issue entitled: Calcium signaling in health and disease. Guest Editors: Geert Bultynck, Jacques Haiech, Claus W. Heizmann, Joachim Krebs, and Marc Moreau.
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Schlichter LC, Jiang J, Wang J, Newell EW, Tsui FWL, Lam D. Regulation of hERG and hEAG channels by Src and by SHP-1 tyrosine phosphatase via an ITIM region in the cyclic nucleotide binding domain. PLoS One 2014; 9:e90024. [PMID: 24587194 PMCID: PMC3938566 DOI: 10.1371/journal.pone.0090024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 01/31/2014] [Indexed: 12/14/2022] Open
Abstract
Members of the EAG K+ channel superfamily (EAG/Kv10.x, ERG/Kv11.x, ELK/Kv12.x subfamilies) are expressed in many cells and tissues. In particular, two prototypes, EAG1/Kv10.1/KCNH1 and ERG1/Kv11.1/KCNH2 contribute to both normal and pathological functions. Proliferation of numerous cancer cells depends on hEAG1, and in some cases, hERG. hERG is best known for contributing to the cardiac action potential, and for numerous channel mutations that underlie ‘long-QT syndrome’. Many cells, particularly cancer cells, express Src-family tyrosine kinases and SHP tyrosine phosphatases; and an imbalance in tyrosine phosphorylation can lead to malignancies, autoimmune diseases, and inflammatory disorders. Ion channel contributions to cell functions are governed, to a large degree, by post-translational modulation, especially phosphorylation. However, almost nothing is known about roles of specific tyrosine kinases and phosphatases in regulating K+ channels in the EAG superfamily. First, we show that tyrosine kinase inhibitor, PP1, and the selective Src inhibitory peptide, Src40-58, reduce the hERG current amplitude, without altering its voltage dependence or kinetics. PP1 similarly reduces the hEAG1 current. Surprisingly, an ‘immuno-receptor tyrosine inhibitory motif’ (ITIM) is present within the cyclic nucleotide binding domain of all EAG-superfamily members, and is conserved in the human, rat and mouse sequences. When tyrosine phosphorylated, this ITIM directly bound to and activated SHP-1 tyrosine phosphatase (PTP-1C/PTPN6/HCP); the first report that a portion of an ion channel is a binding site and activator of a tyrosine phosphatase. Both hERG and hEAG1 currents were decreased by applying active recombinant SHP-1, and increased by the inhibitory substrate-trapping SHP-1 mutant. Thus, hERG and hEAG1 currents are regulated by activated SHP-1, in a manner opposite to their regulation by Src. Given the widespread distribution of these channels, Src and SHP-1, this work has broad implications in cell signaling that controls survival, proliferation, differentiation, and other ERG1 and EAG1 functions in many cell types.
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Affiliation(s)
- Lyanne C. Schlichter
- Genes and Development Division, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
- Department of Physiology University of Toronto, Toronto, Ontario, Canada
- * E-mail:
| | - Jiahua Jiang
- Genes and Development Division, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
| | - John Wang
- Genes and Development Division, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
| | - Evan W. Newell
- Genes and Development Division, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
- Department of Physiology University of Toronto, Toronto, Ontario, Canada
| | - Florence W. L. Tsui
- Genes and Development Division, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
- Department of Immunology, University of Toronto, Toronto, Ontario, Canada
| | - Doris Lam
- Genes and Development Division, Toronto Western Research Institute, University Health Network, Toronto, Ontario, Canada
- Department of Physiology University of Toronto, Toronto, Ontario, Canada
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