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Folini A, Zhang L, Luedi MM, Moolan-Vadackumchery R, Matthiss L, Hoffmann A, Stüber F, Huang MYY. Regulatory effects of microRNAs on monocytic HLA-DR surface expression. Eur J Immunol 2024; 54:e2350756. [PMID: 38778505 DOI: 10.1002/eji.202350756] [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: 09/05/2023] [Revised: 04/25/2024] [Accepted: 05/02/2024] [Indexed: 05/25/2024]
Abstract
Decreased monocytic HLA-DR expression is the most studied biomarker of immune competency in critically ill and autoimmune disease patients. However, the underlying regulatory mechanisms remain largely unknown. One probable HLA-DR dysregulation is through microRNAs. The aim of this study was to investigate the effects of specific microRNAs on HLA-DR expression in human monocytic cells. Four up- and four down-HLA-DR-regulating microRNAs were identified, with hsa-miR-let-7f-2-3p showing the most significant upregulation and hsa-miR-567 and hsa-miR-3972 downregulation. Anti-inflammatory glucocorticoid medication Dexamethasone-decreased HLA-DR was significantly restored by hsa-miR-let-7f-2-3p and hsa-miR-5693. Contrarily, proinflammatory cytokines IFN-γ and TNF-α-increased HLA-DR were significantly reversed by hsa-miR-567. Clinically, paired plasma samples from patients before and one day after cardiac surgery revealed up-regulated expression of hsa-miR-5693, hsa-miR-567, and hsa-miR-3972, following the major surgical trauma. In silico approaches were applied for functional microRNA-mRNA interaction prediction and candidate target genes were confirmed by qPCR analysis. In conclusion, novel monocytic HLA-DR microRNA modulators were identified and validated in vitro. Moreover, both the interaction between the microRNAs and anti- and proinflammatory molecules and the up-regulated microRNAs identified in cardiac surgery highlight the potential clinical relevance of our findings.
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Affiliation(s)
- Anja Folini
- Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Lan Zhang
- Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Markus M Luedi
- Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research, University of Bern, Bern, Switzerland
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland
| | - Robin Moolan-Vadackumchery
- Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Lena Matthiss
- Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Anneliese Hoffmann
- Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Frank Stüber
- Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research, University of Bern, Bern, Switzerland
| | - Melody Ying-Yu Huang
- Department of Anaesthesiology and Pain Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
- Department for BioMedical Research, University of Bern, Bern, Switzerland
- Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH) Zürich, Zürich, Switzerland
- Luzerner Kantonsspital, Augenklinik, Luzern, Switzerland
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2
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Tang Y, Wu X, Li J, Li Y, Xu X, Li G, Zhang P, Qin C, Wu LJ, Tang Z, Tian DS. The Emerging Role of Microglial Hv1 as a Target for Immunomodulation in Myelin Repair. Aging Dis 2024; 15:1176-1203. [PMID: 38029392 PMCID: PMC11081154 DOI: 10.14336/ad.2023.1107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 11/07/2023] [Indexed: 12/01/2023] Open
Abstract
In the central nervous system (CNS), the myelin sheath ensures efficient interconnection between neurons and contributes to the regulation of the proper function of neuronal networks. The maintenance of myelin and the well-organized subtle process of myelin plasticity requires cooperation among myelin-forming cells, glial cells, and neural networks. The process of cooperation is fragile, and the balance is highly susceptible to disruption by microenvironment influences. Reactive microglia play a critical and complicated role in the demyelination and remyelination process. Recent studies have shown that the voltage-gated proton channel Hv1 is selectively expressed in microglia in CNS, which regulates intracellular pH and is involved in the production of reactive oxygen species, underlying multifaceted roles in maintaining microglia function. This paper begins by examining the molecular mechanisms of demyelination and emphasizes the crucial role of the microenvironment in demyelination. It focuses specifically on the role of Hv1 in myelin repair and its therapeutic potential in CNS demyelinating diseases.
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Affiliation(s)
- Yingxin Tang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Xuan Wu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Jiarui Li
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Yuanwei Li
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Xiaoxiao Xu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Gaigai Li
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Ping Zhang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Chuan Qin
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Zhouping Tang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Dai-Shi Tian
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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3
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Catacuzzeno L, Conti F, Franciolini F. Fifty years of gating currents and channel gating. J Gen Physiol 2023; 155:e202313380. [PMID: 37410612 PMCID: PMC10324510 DOI: 10.1085/jgp.202313380] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/12/2023] [Accepted: 06/02/2023] [Indexed: 07/08/2023] Open
Abstract
We celebrate this year the 50th anniversary of the first electrophysiological recordings of the gating currents from voltage-dependent ion channels done in 1973. This retrospective tries to illustrate the context knowledge on channel gating and the impact gating-current recording had then, and how it continued to clarify concepts, elaborate new ideas, and steer the scientific debate in these 50 years. The notion of gating particles and gating currents was first put forward by Hodgkin and Huxley in 1952 as a necessary assumption for interpreting the voltage dependence of the Na and K conductances of the action potential. 20 years later, gating currents were actually recorded, and over the following decades have represented the most direct means of tracing the movement of the gating charges and gaining insights into the mechanisms of channel gating. Most work in the early years was focused on the gating currents from the Na and K channels as found in the squid giant axon. With channel cloning and expression on heterologous systems, other channels as well as voltage-dependent enzymes were investigated. Other approaches were also introduced (cysteine mutagenesis and labeling, site-directed fluorometry, cryo-EM crystallography, and molecular dynamics [MD] modeling) to provide an integrated and coherent view of voltage-dependent gating in biological macromolecules. The layout of this retrospective reflects the past 50 years of investigations on gating currents, first addressing studies done on Na and K channels and then on other voltage-gated channels and non-channel structures. The review closes with a brief overview of how the gating-charge/voltage-sensor movements are translated into pore opening and the pathologies associated with mutations targeting the structures involved with the gating currents.
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Affiliation(s)
- Luigi Catacuzzeno
- Department of Chemistry Biology and Biotechnology, University of Perugia, Perugia, Italy
| | - Franco Conti
- Department of Physics, University of Genova, Genova, Italy
| | - Fabio Franciolini
- Department of Chemistry Biology and Biotechnology, University of Perugia, Perugia, Italy
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4
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Shen Y, Luo Y, Liao P, Zuo Y, Jiang R. Role of the Voltage-Gated Proton Channel Hv1 in Nervous Systems. Neurosci Bull 2023; 39:1157-1172. [PMID: 37029856 PMCID: PMC10313628 DOI: 10.1007/s12264-023-01053-6] [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: 10/12/2022] [Accepted: 02/20/2023] [Indexed: 04/09/2023] Open
Abstract
Hv1 is the only voltage-gated proton-selective channel in mammalian cells. It contains a conserved voltage-sensor domain, shared by a large class of voltage-gated ion channels, but lacks a pore domain. Its primary role is to extrude protons from the cytoplasm upon pH reduction and membrane depolarization. The best-known function of Hv1 is the regulation of cytosolic pH and the nicotinamide adenine dinucleotide phosphate oxidase-dependent production of reactive oxygen species. Accumulating evidence indicates that Hv1 is expressed in nervous systems, in addition to immune cells and others. Here, we summarize the molecular properties, distribution, and physiological functions of Hv1 in the peripheral and central nervous systems. We describe the recently discovered functions of Hv1 in various neurological diseases, including brain or spinal cord injury, ischemic stroke, demyelinating diseases, and pain. We also summarize the current advances in the discovery and application of Hv1-targeted small molecules in neurological diseases. Finally, we discuss the current limitations of our understanding of Hv1 and suggest future research directions.
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Affiliation(s)
- Yu Shen
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, 610000, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, 610000, China
| | - Yuncheng Luo
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, 610000, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, 610000, China
| | - Ping Liao
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, 610000, China
| | - Yunxia Zuo
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, 610000, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, 610000, China
| | - Ruotian Jiang
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, 610000, China.
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, 610000, China.
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5
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Szanto TG, Feher A, Korpos E, Gyöngyösi A, Kállai J, Mészáros B, Ovari K, Lányi Á, Panyi G, Varga Z. 5-Chloro-2-Guanidinobenzimidazole (ClGBI) Is a Non-Selective Inhibitor of the Human H V1 Channel. Pharmaceuticals (Basel) 2023; 16:ph16050656. [PMID: 37242439 DOI: 10.3390/ph16050656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/13/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023] Open
Abstract
5-chloro-2-guanidinobenzimidazole (ClGBI), a small-molecule guanidine derivative, is a known effective inhibitor of the voltage-gated proton (H+) channel (HV1, Kd ≈ 26 μM) and is widely used both in ion channel research and functional biological assays. However, a comprehensive study of its ion channel selectivity determined by electrophysiological methods has not been published yet. The lack of selectivity may lead to incorrect conclusions regarding the role of hHv1 in physiological or pathophysiological responses in vitro and in vivo. We have found that ClGBI inhibits the proliferation of lymphocytes, which absolutely requires the functioning of the KV1.3 channel. We, therefore, tested ClGBI directly on hKV1.3 using a whole-cell patch clamp and found an inhibitory effect similar in magnitude to that seen on hHV1 (Kd ≈ 72 μM). We then further investigated ClGBI selectivity on the hKV1.1, hKV1.4-IR, hKV1.5, hKV10.1, hKV11.1, hKCa3.1, hNaV1.4, and hNaV1.5 channels. Our results show that, besides HV1 and KV1.3, all other off-target channels were inhibited by ClGBI, with Kd values ranging from 12 to 894 μM. Based on our comprehensive data, ClGBI has to be considered a non-selective hHV1 inhibitor; thus, experiments aiming at elucidating the significance of these channels in physiological responses have to be carefully evaluated.
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Affiliation(s)
- Tibor G Szanto
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Adam Feher
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Eva Korpos
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Adrienn Gyöngyösi
- Department of Immunology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Judit Kállai
- ELKH-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- Department of Immunology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Beáta Mészáros
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Krisztian Ovari
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Árpád Lányi
- Department of Immunology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Gyorgy Panyi
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
- ELKH-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Zoltan Varga
- Department of Biophysics & Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
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6
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Cozzolino M, Gyöngyösi A, Korpos E, Gogolak P, Naseem MU, Kállai J, Lanyi A, Panyi G. The Voltage-Gated Hv1 H+ Channel Is Expressed in Tumor-Infiltrating Myeloid-Derived Suppressor Cells. Int J Mol Sci 2023; 24:ijms24076216. [PMID: 37047188 PMCID: PMC10094655 DOI: 10.3390/ijms24076216] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 03/20/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023] Open
Abstract
Myeloid-derived suppressor cells (MDSCs) are key determinants of the immunosuppressive microenvironment in tumors. As ion channels play key roles in the physiology/pathophysiology of immune cells, we aimed at studying the ion channel repertoire in tumor-derived polymorphonuclear (PMN-MDSC) and monocytic (Mo-MDSC) MDSCs. Subcutaneous tumors in mice were induced by the Lewis lung carcinoma cell line (LLC). The presence of PMN-MDSC (CD11b+/Ly6G+) and Mo-MDSCs (CD11b+/Ly6C+) in the tumor tissue was confirmed using immunofluorescence microscopy and cells were identified as CD11b+/Ly6G+ PMN-MDSCs and CD11b+/Ly6C+/F4/80−/MHCII− Mo-MDSCs using flow cytometry and sorting. The majority of the myeloid cells infiltrating the LLC tumors were PMN-MDSC (~60%) as compared to ~10% being Mo-MDSCs. We showed that PMN- and Mo-MDSCs express the Hv1 H+ channel both at the mRNA and at the protein level and that the biophysical and pharmacological properties of the whole-cell currents recapitulate the hallmarks of Hv1 currents: ~40 mV shift in the activation threshold of the current per unit change in the extracellular pH, high H+ selectivity, and sensitivity to the Hv1 inhibitor ClGBI. As MDSCs exert immunosuppression mainly by producing reactive oxygen species which is coupled to Hv1-mediated H+ currents, Hv1 might be an attractive target for inhibition of MDSCs in tumors.
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Affiliation(s)
- Marco Cozzolino
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (M.C.); (E.K.); (M.U.N.)
| | - Adrienn Gyöngyösi
- Department of Immunology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (A.G.); (P.G.); (J.K.); (A.L.)
| | - Eva Korpos
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (M.C.); (E.K.); (M.U.N.)
- ELKH-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Peter Gogolak
- Department of Immunology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (A.G.); (P.G.); (J.K.); (A.L.)
| | - Muhammad Umair Naseem
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (M.C.); (E.K.); (M.U.N.)
| | - Judit Kállai
- Department of Immunology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (A.G.); (P.G.); (J.K.); (A.L.)
- ELKH-DE Cell Biology and Signaling Research Group, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Arpad Lanyi
- Department of Immunology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (A.G.); (P.G.); (J.K.); (A.L.)
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (M.C.); (E.K.); (M.U.N.)
- Correspondence: ; Tel.: +36-52-352201
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7
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Llanos MA, Ventura C, Martín P, Enrique N, Felice JI, Gavernet L, Milesi V. Novel Dimeric hHv1 Model and Structural Bioinformatic Analysis Reveal an ATP-Binding Site Resulting in a Channel Activating Effect. J Chem Inf Model 2022; 62:3200-3212. [PMID: 35758884 DOI: 10.1021/acs.jcim.1c01396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The human voltage-gated proton channel (hHv1) is a highly selective ion channel codified by the HVCN1 gene. It plays a fundamental role in several physiological processes such as innate and adaptive immunity, insulin secretion, and sperm capacitation. Moreover, in humans, a higher hHv1 expression/function has been reported in several types of cancer cells. Here we report a multitemplate homology model of the hHv1 channel, built and refined as a dimer in Rosetta. The model was then subjected to extensive Gaussian accelerated molecular dynamics (GaMD) for enhanced conformational sampling, and representative snapshots were extracted by clustering analysis. Combining different structure- and sequence-based methodologies, we predicted a putative ATP-binding site located on the intracellular portion of the channel. Furthermore, GaMD simulations of the ATP-bound dimeric hHv1 model showed that ATP interacts with a cluster of positively charged residues from the cytoplasmic N and C terminal segments. According to the in silico predictions, we found that 3 mM intracellular ATP significantly increases the H+ current mediated by the hHv1 channel expressed in HEK293 cells and measured by the patch-clamp technique in an inside-out configuration (2.86 ± 0.63 fold over control at +40 mV). When ATP was added on the extracellular side, it was not able to activate the channel supporting the idea that the ATP-binding site resides in the intracellular face of the hHV1 channel. In a physiological and pathophysiological context, this ATP-mediated modulation could integrate the cell metabolic state with the H+ efflux, especially in cells where hHv1 channels are relevant for pH regulation, such as pancreatic β-cells, immune cells, and cancer cells.
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Affiliation(s)
- Manuel A Llanos
- Departamento de Ciencias Biológicas and Laboratorio de Investigación y Desarrollo de Bioactivos (LIDeB), Fac. de Ciencias Exactas, Universidad Nacional de La Plata. La Plata B1900ADU, Buenos Aires, Argentina
| | - Clara Ventura
- Facultad de Ciencias Exactas, Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP), UNLP, CONICET, asociado CIC PBA, La Plata B1900BJW, Buenos Aires, Argentina
| | - Pedro Martín
- Facultad de Ciencias Exactas, Departamento de Ciencias Biológicas, Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP), UNLP, CONICET, asociado CIC PBA, La Plata B1900BJW, Buenos Aires, Argentina
| | - Nicolás Enrique
- Facultad de Ciencias Exactas, Departamento de Ciencias Biológicas, Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP), UNLP, CONICET, asociado CIC PBA, La Plata B1900BJW, Buenos Aires, Argentina
| | - Juan I Felice
- Facultad de Ciencias Exactas, Departamento de Ciencias Biológicas, Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP), UNLP, CONICET, asociado CIC PBA, La Plata B1900BJW, Buenos Aires, Argentina
| | - Luciana Gavernet
- Departamento de Ciencias Biológicas and Laboratorio de Investigación y Desarrollo de Bioactivos (LIDeB), Fac. de Ciencias Exactas, Universidad Nacional de La Plata. La Plata B1900ADU, Buenos Aires, Argentina
| | - Verónica Milesi
- Facultad de Ciencias Exactas, Departamento de Ciencias Biológicas, Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP), UNLP, CONICET, asociado CIC PBA, La Plata B1900BJW, Buenos Aires, Argentina
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8
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Pang H, Li J, Li SJ. Role of the voltage-gated proton channel Hv1 in insulin secretion, glucose homeostasis, and obesity. J Physiol Biochem 2022; 78:593-601. [PMID: 35353324 DOI: 10.1007/s13105-022-00891-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 03/11/2022] [Indexed: 10/18/2022]
Abstract
Diabetes is characterized by an absolutely inadequate insulin secretion (type 1 diabetes mellitus) or a relative deficit in insulin secretion due to insulin resistance (type 2 diabetes mellitus), both of which result in elevated blood glucose. Understanding the molecular mechanisms underlying the pathophysiology of diabetes could lead to the development of new therapeutic approaches. The voltage-gated proton channel Hv1 is an ion channel with specific selectivity for protons, which is regulated by membrane potential and intracellular pH. Recently, our studies showed that Hv1 is expressed in β cells of the endocrine pancreas. Knockout of Hv1 reduces insulin secretion and results in hyperglycemia and glucose intolerance, but not insulin resistance. Furthermore, knockout of Hv1 leads to diet-induced obesity due to inflammation and hepatic steatosis. Increasing evidence suggests that Hv1 plays a pivotal role in glucose homeostasis and lipid metabolism. This review aims to summarize advances made so far in our understanding of the roles of Hv1 in the regulation of insulin secretion in β cells, glucose homeostasis, and obesity.
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Affiliation(s)
- Huimin Pang
- Department of Biophysics, School of Physics, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, 94 Weijin Road, Nankai District, Tianjin, 300071, People's Republic of China
| | - Jinwen Li
- Department of Biophysics, School of Physics, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, 94 Weijin Road, Nankai District, Tianjin, 300071, People's Republic of China
| | - Shu Jie Li
- Department of Biophysics, School of Physics, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, 94 Weijin Road, Nankai District, Tianjin, 300071, People's Republic of China.
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9
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Du H, Pang H, Gao Y, Zhou Y, Li SJ. Deficiency of voltage-gated proton channel Hv1 aggravates ovalbumin-induced allergic lung asthma in mice. Int Immunopharmacol 2021; 96:107640. [PMID: 33866247 DOI: 10.1016/j.intimp.2021.107640] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 03/18/2021] [Accepted: 04/01/2021] [Indexed: 02/07/2023]
Abstract
Asthma is a chronic airway inflammation that caused by many factors. The voltage-gated proton channel Hv1 has been proposed to extrude excessive protons produced by NADPH oxidase (NOX) from cytosol to maintain its activity during respiratory bursts. Here, we showed that loss of Hv1 aggravates ovalbumin (OVA)-induced allergic lung asthma in mice. The numbers of total cells, eosinophils and neutrophils in bronchoalveolar lavage fluid (BALF) of Hv1-deficiency (KO) mice are obviously increased after OVA challenge compared with that of wild-type (WT) mice. Histopathological staining reveals that Hv1-deficiency aggravates OVA-induced inflammatory cell infiltration and goblet cell hyperplasia in lung tissues. The expression of IL-4, IL-5 and IL-13 are markedly increased in lung tissues of OVA-challenged KO mice compared with that of WT mice. Furthermore, the expression levels of NOX2, NOX4 and DUOX1 are dramatically increased, while the expression levels of SOD2 and catalase are significantly reduced in lung tissues of OVA-challenged KO mice compared with that of WT mice. The production of ROS in lung tissues of KO mice is significantly higher than that of WT mice after OVA challenge. Our data suggest that Hv1-deficiency might aggravate the development of allergic asthma through increasing ROS production.
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Affiliation(s)
- Hongyan Du
- Department of Biophysics, School of Physical Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071, China
| | - Huimin Pang
- Department of Biophysics, School of Physical Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071, China
| | - Yingtang Gao
- Tianjin Key Laboratory of Extracorporeal Life Support for Critical Diseases, Institute of Hepatobiliary Disease, Tianjin Third Central Hospital affiliated to Nankai University, 83 Jintang Road, Hedong District, Tianjin 300170, China
| | - Yongfa Zhou
- Department of Biophysics, School of Physical Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071, China
| | - Shu Jie Li
- Department of Biophysics, School of Physical Science, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071, China; Qilu Institute of Technology, Shandong 250200, P. R. China.
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He J, Ritzel RM, Wu J. Functions and Mechanisms of the Voltage-Gated Proton Channel Hv1 in Brain and Spinal Cord Injury. Front Cell Neurosci 2021; 15:662971. [PMID: 33897377 PMCID: PMC8063047 DOI: 10.3389/fncel.2021.662971] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 03/18/2021] [Indexed: 12/25/2022] Open
Abstract
The voltage-gated proton channel Hv1 is a newly discovered ion channel that is highly conserved among species. It is known that Hv1 is not only expressed in peripheral immune cells but also one of the major ion channels expressed in tissue-resident microglia of the central nervous systems (CNS). One key role for Hv1 is its interaction with NADPH oxidase 2 (NOX2) to regulate reactive oxygen species (ROS) and cytosolic pH. Emerging data suggest that excessive ROS production increases and requires proton currents through Hv1 in the injured CNS, and manipulations that ablate Hv1 expression or induce loss of function may provide neuroprotection in CNS injury models including stroke, traumatic brain injury, and spinal cord injury. Recent data demonstrating microglial Hv1-mediated signaling in the pathophysiology of the CNS injury further supports the idea that Hv1 channel may function as a key mechanism in posttraumatic neuroinflammation and neurodegeneration. In this review, we summarize the main findings of Hv1, including its expression pattern, cellular mechanism, role in aging, and animal models of CNS injury and disease pathology. We also discuss the potential of Hv1 as a therapeutic target for CNS injury.
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Affiliation(s)
- Junyun He
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD, United States
| | - Rodney M Ritzel
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD, United States
| | - Junfang Wu
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, MD, United States.,University of Maryland Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD, United States
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11
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Smith CJ, Perfetti TA, King JA. Indirect oxidative stress from pulmonary inflammation exceeds direct oxidative stress from chemical damage to mitochondria. TOXICOLOGY RESEARCH AND APPLICATION 2019. [DOI: 10.1177/2397847319842845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Carr J Smith
- Albemarle Corporation, Charlotte, NC, USA
- Department of Nurse Anesthesia, Florida State University, Tallahassee, FL, USA
| | | | - Judy A King
- Department of Pathology and Translational Pathobiology, LSU Health Shreveport, Shreveport, LA, USA
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12
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Ratanayotha A, Kawai T, Okamura Y. Real-time functional analysis of Hv1 channel in neutrophils: a new approach from zebrafish model. Am J Physiol Regul Integr Comp Physiol 2019; 316:R819-R831. [PMID: 30943046 DOI: 10.1152/ajpregu.00326.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Voltage-gated proton channel (Hv1) has been studied in various immune cells, including neutrophils. However, most studies have taken an in vitro approach using isolated cells or primary cultured cells of mammals; therefore, limited evidence is available on the function of Hv1 in a physiological context. In this study, we have developed the in vivo system that enables real-time functional analysis of Hv1 using zebrafish embryos (Danio rerio). Hvcn1-deficiency (hvcn1-/-) in zebrafish completely abolished voltage-gated proton current, which is typically observed in wild-type neutrophils. Importantly, hvcn1-deficiency significantly reduced reactive oxygen species production and calcium response of zebrafish neutrophils, comparable to the results observed in mammalian models. These findings verify zebrafish Hv1 (DrHv1) as the primary contributor for native Hv1-derived proton current in neutrophils and suggest the conserved function of Hv1 in the immune cells across vertebrate animals. Taking advantage of Hv1 zebrafish model, we compared real-time behaviors of neutrophils between wild-type and hvcn1-/- zebrafish in response to tissue injury and acute bacterial infection. Notably, we observed a significant increase in the number of phagosomes in hvcn1-/- neutrophils, raising a possible link between Hv1 and phagosomal maturation. Furthermore, survival analysis of zebrafish larvae potentially supports a protective role of Hv1 in the innate immune response against systemic bacterial infection. This study represents the influence of Hv1 on neutrophil behaviors and highlights the benefits of in vivo approach toward the understanding of Hv1 in a physiological context.
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Affiliation(s)
- Adisorn Ratanayotha
- Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University , Suita, Osaka , Japan
| | - Takafumi Kawai
- Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University , Suita, Osaka , Japan
| | - Yasushi Okamura
- Laboratory of Integrative Physiology, Department of Physiology, Graduate School of Medicine, Osaka University , Suita, Osaka , Japan
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13
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Boonamnaj P, Sompornpisut P. Effect of Ionization State on Voltage-Sensor Structure in Resting State of the Hv1 Channel. J Phys Chem B 2019; 123:2864-2873. [DOI: 10.1021/acs.jpcb.9b00634] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Panisak Boonamnaj
- Center of Excellence in Computational Chemistry, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Pornthep Sompornpisut
- Center of Excellence in Computational Chemistry, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
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14
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Bronchioloalveolar lung tumors induced in “mice only” by non-genotoxic chemicals are not useful for quantitative assessment of pulmonary adenocarcinoma risk in humans. TOXICOLOGY RESEARCH AND APPLICATION 2018. [DOI: 10.1177/2397847318816617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Chemicals classified as known human carcinogens by International Agency for Research on Cancer (IARC) show a low level of concordance between rodents and humans for induction of pulmonary carcinoma. Rats and mice exposed via inhalation for 2 years show a low level of concordance in both tumor development and organ site location. In 2-year inhalation studies using rats and mice, when pulmonary tumors are seen in only male or female mice or both, but not in either sex of rat, there is a high probability that the murine pulmonary tumor has been produced via Clara cell or club cell (CC) metabolism of the inhaled chemical to a cytotoxic metabolite. Cytotoxicity-induced mitogenesis increases mutagenesis via amplification of the background mutation rate. If the chemical being tested is also negative in the Ames Salmonella mutagenicity assay, and only mouse pulmonary tumors are induced, the probability that this pulmonary tumor is not relevant to human lung cancer risk goes even higher. Mice have a larger percentage of CCs in their distal airways than rats, and a much larger percentage than in humans. The CCs of mice have a much higher concentration of metabolic enzymes capable of metabolizing xenobiotics than CCs in either rats or humans. A principal threat to validity of extrapolating from the murine model lies in the unique capacity of murine CCs to metabolize a significant spectrum of xenobiotics which in turn produces toxicants not seen in rat or human pulmonary pathophysiology.
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15
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Leal-Sena JA, Dos Santos JL, Dos Santos TAR, de Andrade EM, de Oliveira Mendes TA, Santana JO, Mineo TWP, Mineo JR, da Cunha-Júnior JP, Pirovani CP. Toxoplasma gondii antigen SAG2A differentially modulates IL-1β expression in resistant and susceptible murine peritoneal cells. Appl Microbiol Biotechnol 2018; 102:2235-2249. [PMID: 29353306 DOI: 10.1007/s00253-018-8759-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 12/12/2017] [Accepted: 12/17/2017] [Indexed: 12/11/2022]
Abstract
The cell surface of Toxoplasma gondii is covered by antigens (SAGs) from the SRS family anchored by glycosylphosphatidylinositol (GPI) and includes antigens from the SAG2 family. Among these, the SAG2A surface antigen shows great potential in activating humoral responses and has been used in characterizing the acute phase of infection and in the serological diagnosis of toxoplasmosis. In this study, we aimed to evaluate rSAG2A-induced proteins in BALB/c and C57BL/c mice macrophages and to evaluate the phenotypic polarization induced in the process. We treated the peritoneal macrophages from mouse strains that were resistant or susceptible to T. gondii with rSAG2A to analyze their proteomic profile by mass spectrometry and systems biology. We also examined the gene expression of these cells by RT-qPCR using the phenotypic markers of M1 and M2 macrophages. Differences were observed in the expression of proteins involved in the inflammatory process in both resistant and susceptible cells, and macrophages were preferentially induced to obtain a pro-inflammatory immune response (M1) via the overexpression of IL-1β in mice susceptible to this parasite. These data suggest that the SAG2A antigen induces phenotypic and classical activation of macrophages in both resistant and susceptible strains of mice during the acute phase of the disease.
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Affiliation(s)
| | - Jane Lima Dos Santos
- Biothecnology and Genetic Center, State University of Santa Cruz, Ilhéus, BA, Brazil.
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16
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Boonamnaj P, Sompornpisut P. Insight into the Role of the Hv1 C-Terminal Domain in Dimer Stabilization. J Phys Chem B 2018; 122:1037-1048. [PMID: 29290112 DOI: 10.1021/acs.jpcb.7b08669] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The voltage-gated proton-selective channel (Hv1) conducts protons in response to changes in membrane potential. The Hv1 protein forms dimers in the membrane. Crystal structures of Hv1 channels have revealed that the primary contacts between the two monomers are in the C-terminal domain (CTD), which forms a coiled-coil structure. The role of Hv1-CTD in channel assembly and activity is not fully understood. Here, molecular dynamics (MD) simulations of full-length and truncated CTD models of human and mouse Hv1 channels reveal a strong contribution of the CTD to the packing of the transmembrane domains. Simulations of the CTD models highlight four fundamental interactions of the key residues contributing to dimer stability. These include salt bridges, hydrophobic interactions, hydrogen bonds, and a disulfide bond across the dimer interface. At neutral pH, salt-bridge interactions increase dimer stability and the dimer becomes less stable at acidic pH. Hydrophobic core packing of the heptad pattern is important for stability, as shown by favorable nonpolar binding free energies rather than by electrostatic components. Moreover, free-energy calculations indicate that a more uniform hydrophobic core in the coiled-coil structure of the Hv1-NIN, a channel carrying the triple mutation M234N-N235I-V236N, leads to an increase in dimer stability with respect to the wild-type. A Cys disulfide bond has a strong impact on dimer stability by holding the dimer together and facilitating the interactions described above. These results are consistent with dissociative temperatures and energy barriers of dimer dissociation obtained from the temperature-accelerated MD.
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Affiliation(s)
- Panisak Boonamnaj
- Department of Chemistry, Faculty of Science, Chulalongkorn University , Bangkok 10330, Thailand
| | - Pornthep Sompornpisut
- Department of Chemistry, Faculty of Science, Chulalongkorn University , Bangkok 10330, Thailand
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17
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Siddiqui S, Lustig A, Carter A, Sankar M, Daimon CM, Premont RT, Etienne H, van Gastel J, Azmi A, Janssens J, Becker KG, Zhang Y, Wood W, Lehrmann E, Martin JG, Martin B, Taub DD, Maudsley S. Genomic deletion of GIT2 induces a premature age-related thymic dysfunction and systemic immune system disruption. Aging (Albany NY) 2017; 9:706-740. [PMID: 28260693 PMCID: PMC5391227 DOI: 10.18632/aging.101185] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 02/19/2017] [Indexed: 12/12/2022]
Abstract
Recent research has proposed that GIT2 (G protein-coupled receptor kinase interacting protein 2) acts as an integrator of the aging process through regulation of 'neurometabolic' integrity. One of the commonly accepted hallmarks of the aging process is thymic involution. At a relatively young age, 12 months old, GIT2-/- mice present a prematurely distorted thymic structure and dysfunction compared to age-matched 12 month-old wild-type control (C57BL/6) mice. Disruption of thymic structure in GIT2-/- (GIT2KO) mice was associated with a significant reduction in the expression of the cortical thymic marker, Troma-I (cytokeratin 8). Double positive (CD4+CD8+) and single positive CD4+ T cells were also markedly reduced in 12 month-old GIT2KO mice compared to age-matched control wild-type mice. Coincident with this premature thymic disruption in GIT2KO mice was the unique generation of a novel cervical 'organ', i.e. 'parathymic lobes'. These novel organs did not exhibit classical peripheral lymph node-like characteristics but expressed high levels of T cell progenitors that were reflexively reduced in GIT2KO thymi. Using signaling pathway analysis of GIT2KO thymus and parathymic lobe transcriptomic data we found that the molecular signaling functions lost in the dysfunctional GIT2KO thymus were selectively reinstated in the novel parathymic lobe - suggestive of a compensatory effect for the premature thymic disruption. Broader inspection of high-dimensionality transcriptomic data from GIT2KO lymph nodes, spleen, thymus and parathymic lobes revealed a systemic alteration of multiple proteins (Dbp, Tef, Per1, Per2, Fbxl3, Ddit4, Sin3a) involved in the multidimensional control of cell cycle clock regulation, cell senescence, cellular metabolism and DNA damage. Altered cell clock regulation across both immune and non-immune tissues therefore may be responsible for the premature 'aging' phenotype of GIT2KO mice.
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Affiliation(s)
- Sana Siddiqui
- Receptor Pharmacology Unit, Laboratory of Neurosciences, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD 21224, USA
| | - Ana Lustig
- Laboratory of Molecular Biology and Immunology, NIA, NIH, Baltimore, MD 21224, USA
| | - Arnell Carter
- Laboratory of Molecular Biology and Immunology, NIA, NIH, Baltimore, MD 21224, USA
| | - Mathavi Sankar
- Metabolism Unit, Laboratory of Clinical Investigation, NIA, NIH, Baltimore, MD 21224, USA
| | - Caitlin M Daimon
- Metabolism Unit, Laboratory of Clinical Investigation, NIA, NIH, Baltimore, MD 21224, USA
| | | | - Harmonie Etienne
- Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, Belgium
| | - Jaana van Gastel
- Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, Belgium
| | - Abdelkrim Azmi
- Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, Belgium
| | - Jonathan Janssens
- Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, Belgium
| | - Kevin G Becker
- Gene Expression and Genomics Unit, Research Resources Branch, NIA, NIH, Baltimore, MD 21224, USA
| | - Yongqing Zhang
- Gene Expression and Genomics Unit, Research Resources Branch, NIA, NIH, Baltimore, MD 21224, USA
| | - William Wood
- Gene Expression and Genomics Unit, Research Resources Branch, NIA, NIH, Baltimore, MD 21224, USA
| | - Elin Lehrmann
- Gene Expression and Genomics Unit, Research Resources Branch, NIA, NIH, Baltimore, MD 21224, USA
| | - James G Martin
- Research Institute of the MUHC, Centre for Translational Biology (CTB), Meakins-Christie Laboratories, McGill University, Montreal, QC, H4A 3J1, Canada
| | - Bronwen Martin
- Metabolism Unit, Laboratory of Clinical Investigation, NIA, NIH, Baltimore, MD 21224, USA
| | - Dennis D Taub
- Laboratory of Molecular Biology and Immunology, NIA, NIH, Baltimore, MD 21224, USA
| | - Stuart Maudsley
- Receptor Pharmacology Unit, Laboratory of Neurosciences, National Institute on Aging (NIA), National Institutes of Health (NIH), Baltimore, MD 21224, USA.,Translational Neurobiology Group, VIB Department of Molecular Genetics, University of Antwerp, Belgium
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18
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Jonsson S, Sveinbjornsson G, de Lapuente Portilla AL, Swaminathan B, Plomp R, Dekkers G, Ajore R, Ali M, Bentlage AEH, Elmér E, Eyjolfsson GI, Gudjonsson SA, Gullberg U, Gylfason A, Halldorsson BV, Hansson M, Holm H, Johansson Å, Johnsson E, Jonasdottir A, Ludviksson BR, Oddsson A, Olafsson I, Olafsson S, Sigurdardottir O, Sigurdsson A, Stefansdottir L, Masson G, Sulem P, Wuhrer M, Wihlborg AK, Thorleifsson G, Gudbjartsson DF, Thorsteinsdottir U, Vidarsson G, Jonsdottir I, Nilsson B, Stefansson K. Identification of sequence variants influencing immunoglobulin levels. Nat Genet 2017. [DOI: 10.1038/ng.3897] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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19
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Wright BJ, Bickham-Wright U, Yoshino TP, Jackson MB. H+ channels in embryonic Biomphalaria glabrata cell membranes: Putative roles in snail host-schistosome interactions. PLoS Negl Trop Dis 2017; 11:e0005467. [PMID: 28319196 PMCID: PMC5373640 DOI: 10.1371/journal.pntd.0005467] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 03/30/2017] [Accepted: 03/07/2017] [Indexed: 01/19/2023] Open
Abstract
The human blood fluke Schistosoma mansoni causes intestinal schistosomiasis, a widespread neglected tropical disease. Infection of freshwater snails Biomphalaria spp. is an essential step in the transmission of S. mansoni to humans, although the physiological interactions between the parasite and its obligate snail host that determine success or failure are still poorly understood. In the present study, the B. glabrata embryonic (Bge) cell line, a widely used in vitro model for hemocyte-like activity, was used to investigate membrane properties, and assess the impact of larval transformation proteins (LTP) on identified ion channels. Whole-cell patch clamp recordings from Bge cells demonstrated that a Zn2+-sensitive H+ channel serves as the dominant plasma membrane conductance. Moreover, treatment of Bge cells with Zn2+ significantly inhibited an otherwise robust production of reactive oxygen species (ROS), thus implicating H+ channels in the regulation of this immune function. A heat-sensitive component of LTP appears to target H+ channels, enhancing Bge cell H+ current over 2-fold. Both Bge cells and B. glabrata hemocytes express mRNA encoding a hydrogen voltage-gated channel 1 (HVCN1)-like protein, although its function in hemocytes remains to be determined. This study is the first to identify and characterize an H+ channel in non-neuronal cells of freshwater molluscs. Importantly, the involvement of these channels in ROS production and their modulation by LTP suggest that these channels may function in immune defense responses against larval S. mansoni.
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Affiliation(s)
- Brandon J. Wright
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Utibe Bickham-Wright
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Timothy P. Yoshino
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Meyer B. Jackson
- Department of Neuroscience, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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Nicotine inhibits activation of microglial proton currents via interactions with α7 acetylcholine receptors. J Physiol Sci 2016; 67:235-245. [PMID: 27256075 PMCID: PMC5910455 DOI: 10.1007/s12576-016-0460-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 05/12/2016] [Indexed: 01/03/2023]
Abstract
Alpha 7 subunits of nicotinic acetylcholine receptors (nAChRs) are expressed in microglia and are involved in the suppression of neuroinflammation. Over the past decade, many reports show beneficial effects of nicotine, though little is known about the mechanism. Here we show that nicotine inhibits lipopolysaccharide (LPS)-induced proton (H+) currents and morphological change by using primary cultured microglia. The H+ channel currents were measured by whole-cell patch clamp method under voltage-clamp condition. Increased H+ current in activated microglia was attenuated by blocking NADPH oxidase. The inhibitory effect of nicotine was due to the activation of α7 nAChR, not a direct action on the H+ channels, because the effects of nicotine was cancelled by α7 nAChR antagonists. Neurotoxic effect of LPS-activated microglia due to inflammatory cytokines was also attenuated by pre-treatment of microglia with nicotine. These results suggest that α7 nAChRs in microglia may be a therapeutic target in neuroinflammatory diseases.
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