1
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Miao L, Yuan Z, Zhang S, Zhang G. Honokiol alleviates monosodium urate-induced gouty pain by inhibiting voltage-gated proton channels in mice. Inflammopharmacology 2024; 32:2413-2425. [PMID: 38829504 DOI: 10.1007/s10787-024-01498-9] [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: 01/09/2024] [Accepted: 05/23/2024] [Indexed: 06/05/2024]
Abstract
OBJECTIVE To investigate whether honokiol (HNK) acted as an analgesic in connection with inhibiting the voltage-gated proton channel (Hv1). METHODS The model of gouty arthritis was induced by injecting monosodium urate (MSU) crystals into the hind ankle joint of mice. HNK was given by intragastric administration. Ankle swelling degree and mechanical allodynia were evaluated using ankle joint circumference measurement and von Frey filaments, respectively. Hv1 current, tail current, and action potential in dorsal root ganglion (DRG) neurons were recorded with patch-clamp techniques. RESULTS HNK (10, 20, 40 mg/kg) alleviated inflammatory response and mechanical allodynia in a dose-dependent manner. In normal DRG neurons, 50 µM Zn2+ or 2-GBI significantly inhibited the Hv1 current and the current density of Hv1 increased with increasing pH gradient. The amplitude of Hv1 current significantly increased on the 3rd after MSU treatment, and HNK dose-dependently reversed the upregulation of Hv1 current. Compared with MSU group, 40 mg/kg HNK shifted the activation curve to the direction of more positive voltage and increased reversal potential to the normal level. In addition, 40 mg/kg HNK reversed the down-regulation of tail current deactivation time constant (τtail) but did not alter the neuronal excitability of DRG neurons in gouty mice. CONCLUSION HNK may be a potential analgesic by inhibiting Hv1 current.
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Affiliation(s)
- Lurong Miao
- Department of Clinical Pharmacy, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing, 210009, China
| | - Ziqi Yuan
- Department of Clinical Pharmacy, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing, 210009, China
| | - Shijia Zhang
- School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China
| | - Guangqin Zhang
- Department of Clinical Pharmacy, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing, 210009, China.
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2
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Li Q, Gao H, Zhao Y, Zhou B, Yu L, Huang Q, Jiang L, Gao J. Covalent Organic Framework Interlayer Spacings as Perfectly Selective Artificial Proton Channels. Angew Chem Int Ed Engl 2024; 63:e202402094. [PMID: 38581623 DOI: 10.1002/anie.202402094] [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: 01/30/2024] [Revised: 03/16/2024] [Accepted: 04/03/2024] [Indexed: 04/08/2024]
Abstract
Biological proton channels have perfect selectivity in aqueous environment against almost all ions and molecules, a property that differs itself from other biological channels and a feature that remains challenging to realize for bulk artificial materials. The biological perfect selectivity originates from the fact that the channel has almost no free space for ion or water transport but generates a hydrogen bonded wire in the presence of protons to allow the proton hopping. Inspired by this, we used the interlayer spacings of covalent organic framework materials consisting of hydrophilic functional groups as perfectly selective artificial proton channels. The interlayer spacings are so narrow that no atoms or molecules can diffuse through. However, protons exhibit a diffusivity in the same order of magnitude as that in bulk water. Density functional theory calculations show that water molecules and the COF material form hydrogen bonded wires, allowing the proton hopping. We further demonstrate that the proton transport rate can be tuned by adjusting the acidity of the functional groups.
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Affiliation(s)
- Qi Li
- School of Chemical Engineering, Sichuan University, 610065, Chengdu, China
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, China
| | - Hongfei Gao
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, China
| | - Yongye Zhao
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, China
| | - Bo Zhou
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, China
| | - Lei Yu
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, China
| | - Qingsong Huang
- School of Chemical Engineering, Sichuan University, 610065, Chengdu, China
| | - Lei Jiang
- CAS Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190, Beijing, P. R. China
| | - Jun Gao
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 266101, Qingdao, China
- Shandong Energy Institute, 266101, Qingdao, P. R. China
- Qingdao New Energy Shandong Laboratory, 266101, Qingdao, P. R. China
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3
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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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4
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Ayuyan AG, Cherny VV, Chaves G, Musset B, Cohen FS, DeCoursey TE. Interaction with stomatin directs human proton channels into cholesterol-dependent membrane domains. Biophys J 2024:S0006-3495(24)00168-1. [PMID: 38444158 DOI: 10.1016/j.bpj.2024.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 01/24/2024] [Accepted: 03/01/2024] [Indexed: 03/07/2024] Open
Abstract
Many membrane proteins are modulated by cholesterol. Here we report profound effects of cholesterol depletion and restoration on the human voltage-gated proton channel, hHV1, in excised patches but negligible effects in the whole-cell configuration. Despite the presence of a putative cholesterol-binding site, a CARC motif in hHV1, mutation of this motif did not affect cholesterol effects. The murine HV1 lacks a CARC sequence but displays similar cholesterol effects. These results argue against a direct effect of cholesterol on the HV1 protein. However, the data are fully explainable if HV1 preferentially associates with cholesterol-dependent lipid domains, or "rafts." The rafts would be expected to concentrate in the membrane/glass interface and to be depleted from the electrically accessible patch membrane. This idea is supported by evidence that HV1 channels can diffuse between seal and patch membranes when suction is applied. Simultaneous truncation of the large intracellular N and C termini of hHV1 greatly attenuated the cholesterol effect, but C truncation alone did not; this suggests that the N terminus is the region of attachment to lipid domains. Searching for abundant raft-associated proteins led to stomatin. Co-immunoprecipitation experiment results were consistent with hHV1 binding to stomatin. The stomatin-mediated association of HV1 with cholesterol-dependent lipid domains provides a mechanism for cells to direct HV1 to subcellular locations where it is needed, such as the phagosome in leukocytes.
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Affiliation(s)
- Artem G Ayuyan
- Department of Physiology & Biophysics, Rush University, Chicago, Illinois.
| | - Vladimir V Cherny
- Department of Physiology & Biophysics, Rush University, Chicago, Illinois
| | - Gustavo Chaves
- Institut für Physiologie, Pathophysiologie und Biophysik, CPPB, Paracelsus Medical University, Nürnberg, Germany
| | - Boris Musset
- Institut für Physiologie, Pathophysiologie und Biophysik, CPPB, Paracelsus Medical University, Nürnberg, Germany
| | - Fredric S Cohen
- Department of Physiology & Biophysics, Rush University, Chicago, Illinois
| | - Thomas E DeCoursey
- Department of Physiology & Biophysics, Rush University, Chicago, Illinois.
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5
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Zhang L, Wu X, Cao X, Rao K, Hong L. Trp207 regulation of voltage-dependent activation of human H v1 proton channel. J Biol Chem 2024; 300:105674. [PMID: 38272234 PMCID: PMC10875263 DOI: 10.1016/j.jbc.2024.105674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/08/2024] [Accepted: 01/13/2024] [Indexed: 01/27/2024] Open
Abstract
In voltage-gated Na+ and K+ channels, the hydrophobicity of noncharged residues in the S4 helix has been shown to regulate the S4 movement underlying the process of voltage-sensing domain (VSD) activation. In voltage-gated proton channel Hv1, there is a bulky noncharged tryptophan residue located at the S4 transmembrane segment. This tryptophan remains entirely conserved across all Hv1 members but is not seen in other voltage-gated ion channels, indicating that the tryptophan contributes different roles in VSD activation. The conserved tryptophan of human voltage-gated proton channel Hv1 is Trp207 (W207). Here, we showed that W207 modifies human Hv1 voltage-dependent activation, and small residues replacement at position 207 strongly perturbs Hv1 channel opening and closing, and the size of the side chain instead of the hydrophobic group of W207 regulates the transition between closed and open states of the channel. We conclude that the large side chain of tryptophan controls the energy barrier during the Hv1 VSD transition.
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Affiliation(s)
- Lu Zhang
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Xin Wu
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Xinyu Cao
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Khushi Rao
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Liang Hong
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Biomedical Engineering, University of Illinois at Chicago, Chicago, Illinois, USA; Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, Illinois, USA.
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6
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DeCoursey TE. Transcendent Aspects of Proton Channels. Annu Rev Physiol 2024; 86:357-377. [PMID: 37931166 PMCID: PMC10938948 DOI: 10.1146/annurev-physiol-042222-023242] [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] [Indexed: 11/08/2023]
Abstract
A handful of biological proton-selective ion channels exist. Some open at positive or negative membrane potentials, others open at low or high pH, and some are light activated. This review focuses on common features that result from the unique properties of protons. Proton conduction through water or proteins differs qualitatively from that of all other ions. Extraordinary proton selectivity is needed to ensure that protons permeate and other ions do not. Proton selectivity arises from a proton pathway comprising a hydrogen-bonded chain that typically includes at least one titratable amino acid side chain. The enormously diverse functions of proton channels in disparate regions of the phylogenetic tree can be summarized by considering the chemical and electrical consequences of proton flux across membranes. This review discusses examples of cells in which proton efflux serves to increase pHi, decrease pHo, control the membrane potential, generate action potentials, or compensate transmembrane movement of electrical charge.
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Affiliation(s)
- Thomas E DeCoursey
- Department of Physiology & Biophysics, Rush University, Chicago, Illinois, USA;
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7
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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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8
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Chaves G, Jardin C, Derst C, Musset B. Voltage-Gated Proton Channels in the Tree of Life. Biomolecules 2023; 13:1035. [PMID: 37509071 PMCID: PMC10377628 DOI: 10.3390/biom13071035] [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: 05/14/2023] [Revised: 06/14/2023] [Accepted: 06/21/2023] [Indexed: 07/30/2023] Open
Abstract
With a single gene encoding HV1 channel, proton channel diversity is particularly low in mammals compared to other members of the superfamily of voltage-gated ion channels. Nonetheless, mammalian HV1 channels are expressed in many different tissues and cell types where they exert various functions. In the first part of this review, we regard novel aspects of the functional expression of HV1 channels in mammals by differentially comparing their involvement in (1) close conjunction with the NADPH oxidase complex responsible for the respiratory burst of phagocytes, and (2) in respiratory burst independent functions such as pH homeostasis or acid extrusion. In the second part, we dissect expression of HV channels within the eukaryotic tree of life, revealing the immense diversity of the channel in other phylae, such as mollusks or dinoflagellates, where several genes encoding HV channels can be found within a single species. In the last part, a comprehensive overview of the biophysical properties of a set of twenty different HV channels characterized electrophysiologically, from Mammalia to unicellular protists, is given.
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Affiliation(s)
- Gustavo Chaves
- Center of Physiology, Pathophysiology and Biophysics, The Nuremberg Location, Paracelsus Medical University, 90419 Nuremberg, Germany
| | - Christophe Jardin
- Center of Physiology, Pathophysiology and Biophysics, The Nuremberg Location, Paracelsus Medical University, 90419 Nuremberg, Germany
| | - Christian Derst
- Center of Physiology, Pathophysiology and Biophysics, The Nuremberg Location, Paracelsus Medical University, 90419 Nuremberg, Germany
| | - Boris Musset
- Center of Physiology, Pathophysiology and Biophysics, The Nuremberg Location, Paracelsus Medical University, 90419 Nuremberg, Germany
- Center of Physiology, Pathophysiology and Biophysics, The Salzburg Location, Paracelsus Medical University, 5020 Salzburg, Austria
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9
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Hernandez-Espinosa DR, Gale JR, Scrabis MG, Aizenman E. Microglial reprogramming by Hv1 antagonism protects neurons from inflammatory and glutamate toxicity. J Neurochem 2023; 165:29-54. [PMID: 36625847 PMCID: PMC10106429 DOI: 10.1111/jnc.15760] [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: 09/23/2022] [Revised: 12/28/2022] [Accepted: 01/02/2023] [Indexed: 01/11/2023]
Abstract
Although the precise mechanisms determining the neurotoxic or neuroprotective activation phenotypes in microglia remain poorly characterized, metabolic changes in these cells appear critical for these processes. As cellular metabolism can be tightly regulated by changes in intracellular pH, we tested whether pharmacological targeting of the microglial voltage-gated proton channel 1 (Hv1), an important regulator of intracellular pH, is critical for activated microglial reprogramming. Using a mouse microglial cell line and mouse primary microglia cultures, either alone, or co-cultured with rat cerebrocortical neurons, we characterized in detail the microglial activation profile in the absence and presence of Hv1 inhibition. We observed that activated microglia neurotoxicity was mainly attributable to the release of tumor necrosis factor alpha, reactive oxygen species, and zinc. Strikingly, pharmacological inhibition of Hv1 largely abrogated inflammatory neurotoxicity not only by reducing the production of cytotoxic mediators but also by promoting neurotrophic molecule production and restraining excessive phagocytic activity. Importantly, the Hv1-sensitive change from a pro-inflammatory to a neuroprotective phenotype was associated with metabolic reprogramming, particularly via a boost in NADH availability and a reduction in lactate. Most critically, Hv1 antagonism not only reduced inflammatory neurotoxicity but also promoted microglia-dependent neuroprotection against a separate excitotoxic injury. Our results strongly suggest that Hv1 blockers may provide an important therapeutic tool against a wide range of inflammatory neurodegenerative disorders.
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Affiliation(s)
- Diego R Hernandez-Espinosa
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Jenna R Gale
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Mia G Scrabis
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Elias Aizenman
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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10
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El Chemaly A, Jaquet V, Cambet Y, Caillon A, Cherpin O, Balafa A, Krause KH, Demaurex N. Discovery and validation of new Hv1 proton channel inhibitors with onco-therapeutic potential. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119415. [PMID: 36640925 DOI: 10.1016/j.bbamcr.2022.119415] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 12/15/2022] [Accepted: 12/16/2022] [Indexed: 01/13/2023]
Abstract
The voltage-gated hydrogen channel Hv1 encoded in humans by the HVCN1 gene is a highly selective proton channel that allows large fluxes of protons across biological membranes. Hv1 form functional dimers of four transmembrane spanning proteins resembling the voltage sensing domain of potassium channels. Each subunit is highly selective for protons and is controlled by changes in the transmembrane voltage and pH gradient. Hv1 is most expressed in phagocytic cells where it sustains NADPH oxidase-dependent bactericidal function and was reported to facilitate antibody production by B cells and to promote the maturation and motility of spermatocytes. Hv1 contributes to neuroinflammation following brain damage and favors cancer progression possibly by extruding protons generated during aerobic glycolysis of cancer cells. Lack of specific Hv1 inhibitors has hampered translation of this knowledge to treat immune, fertility, or malignancy diseases. In this study, we show that the genetic deletion of Hv1 delays tumor development in a mouse model of granulocytic sarcoma and report the discovery and characterization of two novel bioavailable inhibitors of Hv1 channels that we validate by orthogonal assays and electrophysiological recordings.
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Affiliation(s)
- Antoun El Chemaly
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva 1211, Switzerland
| | - Vincent Jaquet
- Department of Pathology and Immunology, University of Geneva, Geneva 1211, Switzerland; READs unit, University of Geneva, Geneva 1211, Switzerland
| | - Yves Cambet
- READs unit, University of Geneva, Geneva 1211, Switzerland
| | - Aurélie Caillon
- Department of Pathology and Immunology, University of Geneva, Geneva 1211, Switzerland
| | - Ophélie Cherpin
- Department of Pathology and Immunology, University of Geneva, Geneva 1211, Switzerland
| | - Alexia Balafa
- Department of Pathology and Immunology, University of Geneva, Geneva 1211, Switzerland
| | - Karl-Heinz Krause
- Department of Pathology and Immunology, University of Geneva, Geneva 1211, Switzerland
| | - Nicolas Demaurex
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva 1211, Switzerland.
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11
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Naish E, Wood AJT, Stewart AP, Routledge M, Morris AC, Chilvers ER, Lodge KM. The formation and function of the neutrophil phagosome. Immunol Rev 2023; 314:158-180. [PMID: 36440666 PMCID: PMC10952784 DOI: 10.1111/imr.13173] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Neutrophils are the most abundant circulating leukocyte and are crucial to the initial innate immune response to infection. One of their key pathogen-eliminating mechanisms is phagocytosis, the process of particle engulfment into a vacuole-like structure called the phagosome. The antimicrobial activity of the phagocytic process results from a collaboration of multiple systems and mechanisms within this organelle, where a complex interplay of ion fluxes, pH, reactive oxygen species, and antimicrobial proteins creates a dynamic antimicrobial environment. This complexity, combined with the difficulties of studying neutrophils ex vivo, has led to gaps in our knowledge of how the neutrophil phagosome optimizes pathogen killing. In particular, controversy has arisen regarding the relative contribution and integration of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-derived antimicrobial agents and granule-delivered antimicrobial proteins. Clinical syndromes arising from dysfunction in these systems in humans allow useful insight into these mechanisms, but their redundancy and synergy add to the complexity. In this article, we review the current knowledge regarding the formation and function of the neutrophil phagosome, examine new insights into the phagosomal environment that have been permitted by technological advances in recent years, and discuss aspects of the phagocytic process that are still under debate.
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Affiliation(s)
- Emily Naish
- National Heart and Lung InstituteImperial College LondonLondonUK
| | - Alexander JT Wood
- Medical SchoolUniversity of Western AustraliaPerthAustralia
- Department of Critical CareUniversity of MelbourneMelbourneAustralia
| | | | - Matthew Routledge
- Department of MedicineUniversity of CambridgeCambridgeUK
- Division of Immunology, Department of PathologyUniversity of CambridgeCambridgeUK
| | - Andrew Conway Morris
- Department of MedicineUniversity of CambridgeCambridgeUK
- Division of Immunology, Department of PathologyUniversity of CambridgeCambridgeUK
| | - Edwin R Chilvers
- National Heart and Lung InstituteImperial College LondonLondonUK
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12
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Chaves G, Ayuyan AG, Cherny VV, Morgan D, Franzen A, Fieber L, Nausch L, Derst C, Mahorivska I, Jardin C, DeCoursey TE, Musset B. Unexpected expansion of the voltage-gated proton channel family. FEBS J 2023; 290:1008-1026. [PMID: 36062330 PMCID: PMC10911540 DOI: 10.1111/febs.16617] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 08/17/2022] [Accepted: 09/02/2022] [Indexed: 11/27/2022]
Abstract
Voltage-gated ion channels, whose first identified function was to generate action potentials, are divided into subfamilies with numerous members. The family of voltage-gated proton channels (HV ) is tiny. To date, all species found to express HV have exclusively one gene that codes for this unique ion channel. Here we report the discovery and characterization of three proton channel genes in the classical model system of neural plasticity, Aplysia californica. The three channels (AcHV 1, AcHV 2, and AcHV 3) are distributed throughout the whole animal. Patch-clamp analysis confirmed proton selectivity of these channels but they all differed markedly in gating. AcHV 1 gating resembled HV in mammalian cells where it is responsible for proton extrusion and charge compensation. AcHV 2 activates more negatively and conducts extensive inward proton current, properties likely to acidify the cytosol. AcHV 3, which differs from AcHV 1 and AcHV 2 in lacking the first arginine in the S4 helix, exhibits proton selective leak currents and weak voltage dependence. We report the expansion of the proton channel family, demonstrating for the first time the expression of three functionally distinct proton channels in a single species.
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Affiliation(s)
- Gustavo Chaves
- Center of Physiology, Pathophysiology and Biophysics, Paracelsus Medical University, Nuremberg, Germany
| | - Artem G Ayuyan
- Department of Physiology & Biophysics, Rush University, Chicago, IL, USA
| | - Vladimir V Cherny
- Department of Physiology & Biophysics, Rush University, Chicago, IL, USA
| | - Deri Morgan
- Department of Radiation Oncology, University of Kansas Medical Center, MO, USA
| | - Arne Franzen
- Institute of Biological Information Processing, Molecular and Cellular Physiology (IBI-1), Jülich, Germany
| | - Lynne Fieber
- Department of Marine Biology and Ecology - Rosenstiel School of Marine and Atmospheric Science, Miami, FL, USA
| | - Lydia Nausch
- Center of Physiology, Pathophysiology and Biophysics, Paracelsus Medical University, Nuremberg, Germany
- Department of Agriculture, Food and Nutrition, Institute of Nutrition and Food Supply Management, University of Applied Sciences Weihenstephan-Triesdorf, Freising, Germany
| | - Christian Derst
- Center of Physiology, Pathophysiology and Biophysics, Paracelsus Medical University, Nuremberg, Germany
| | - Iryna Mahorivska
- Center of Physiology, Pathophysiology and Biophysics, Paracelsus Medical University, Nuremberg, Germany
| | - Christophe Jardin
- Center of Physiology, Pathophysiology and Biophysics, Paracelsus Medical University, Nuremberg, Germany
| | - Thomas E DeCoursey
- Department of Physiology & Biophysics, Rush University, Chicago, IL, USA
| | - Boris Musset
- Center of Physiology, Pathophysiology and Biophysics, Paracelsus Medical University, Nuremberg, Germany
- Center of Physiology, Pathophysiology and Biophysics, Paracelsus Medical University, Salzburg, Austria
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13
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Li S, Al-Sheikh U, Chen Y, Kang L. Nematode homologs of the sour taste receptor Otopetrin1 are evolutionarily conserved acid-sensitive proton channels. Front Cell Dev Biol 2023; 11:1133890. [PMID: 36776560 PMCID: PMC9909269 DOI: 10.3389/fcell.2023.1133890] [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: 12/29/2022] [Accepted: 01/16/2023] [Indexed: 01/27/2023] Open
Abstract
Numerous taste receptors and related molecules have been identified in vertebrates and invertebrates. Otopetrin1 has recently been identified as mammalian sour taste receptor which is essential for acid sensation. However, whether other Otopetrin proteins are involved in PH-sensing remains unknown. In C. elegans, there are eight otopetrin homologous genes but their expression patterns and functions have not been reported so far. Through heterologous expression in HEK293T cells, we found that ceOTOP1a can be activated by acid in NMDG+ solution without conventional cations, which generated inward currents and can be blocked by zinc ions. Moreover, we found that Otopetrin channels are widely expressed in numerous tissues, especially in sensory neurons in the nematode. These results suggest that the biophysical characteristics of the Otopetrin channels in nematodes are generally conserved. However, a series of single gene mutations of otopetrins, which were constructed by CRISPR-Cas9 method, did not affect either calcium responses in ASH polymodal sensory neurons to acid stimulation or acid avoidance behaviors, suggesting that Otopetrin channels might have diverse functions among species. This study reveals that nematode Otopetrins are evolutionarily conserved acid-sensitive proton channels, and provides a framework for further revealing the function and mechanisms of Otopetrin channels in both invertebrates and vertebrates.
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Affiliation(s)
- Shitian Li
- Department of Neurobiology and Department of Neurosurgery of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China,Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China,NHC and CAMS Key Laboratory of Medical Neurobiology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Umar Al-Sheikh
- Department of Neurobiology and Department of Neurosurgery of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China,Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China,NHC and CAMS Key Laboratory of Medical Neurobiology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yili Chen
- Department of Neurobiology and Department of Neurosurgery of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China,*Correspondence: Yili Chen, ; Lijun Kang,
| | - Lijun Kang
- Department of Neurobiology and Department of Neurosurgery of the Fourth Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China,Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China,NHC and CAMS Key Laboratory of Medical Neurobiology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China,*Correspondence: Yili Chen, ; Lijun Kang,
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14
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Alvear-Arias JJ, Pena-Pichicoi A, Carrillo C, Fernandez M, Gonzalez T, Garate JA, Gonzalez C. Role of voltage-gated proton channel (Hv1) in cancer biology. Front Pharmacol 2023; 14:1175702. [PMID: 37153807 PMCID: PMC10157179 DOI: 10.3389/fphar.2023.1175702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/11/2023] [Indexed: 05/10/2023] Open
Abstract
The acid-base characteristics of tumor cells and the other elements that compose the tumor microenvironment have been topics of scientific interest in oncological research. There is much evidence confirming that pH conditions are maintained by changes in the patterns of expression of certain proton transporters. In the past decade, the voltage-gated proton channel (Hv1) has been added to this list and is increasingly being recognized as a target with onco-therapeutic potential. The Hv1 channel is key to proton extrusion for maintaining a balanced cytosolic pH. This protein-channel is expressed in a myriad of tissues and cell lineages whose functions vary from producing bioluminescence in dinoflagellates to alkalizing spermatozoa cytoplasm for reproduction, and regulating the respiratory burst for immune system response. It is no wonder that in acidic environments such as the tumor microenvironment, an exacerbated expression and function of this channel has been reported. Indeed, multiple studies have revealed a strong relationship between pH balance, cancer development, and the overexpression of the Hv1 channel, being proposed as a marker for malignancy in cancer. In this review, we present data that supports the idea that the Hv1 channel plays a significant role in cancer by maintaining pH conditions that favor the development of malignancy features in solid tumor models. With the antecedents presented in this bibliographic report, we want to strengthen the idea that the Hv1 proton channel is an excellent therapeutic strategy to counter the development of solid tumors.
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Affiliation(s)
- Juan J. Alvear-Arias
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Millennium Nucleus in NanoBioPhysics, Universidad de Valparaíso, Valparaíso, Chile
| | - Antonio Pena-Pichicoi
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Millennium Nucleus in NanoBioPhysics, Universidad de Valparaíso, Valparaíso, Chile
| | - Christian Carrillo
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Millennium Nucleus in NanoBioPhysics, Universidad de Valparaíso, Valparaíso, Chile
| | - Miguel Fernandez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Millennium Nucleus in NanoBioPhysics, Universidad de Valparaíso, Valparaíso, Chile
| | - Tania Gonzalez
- National Center for Minimally Invasive Surgery, La Habana, Cuba
| | - Jose A. Garate
- Millennium Nucleus in NanoBioPhysics, Universidad de Valparaíso, Valparaíso, Chile
- Facultad de Ingeniería y Tecnología, Universidad San Sebastián, Santiago, Chile
- Centro Científico y Tecnológico de Excelencia Ciencia y Vida, Santiago, Chile
| | - Carlos Gonzalez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Millennium Nucleus in NanoBioPhysics, Universidad de Valparaíso, Valparaíso, Chile
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL, United States
- *Correspondence: Carlos Gonzalez,
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15
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Papp F, Toombes GES, Pethő Z, Bagosi A, Feher A, Almássy J, Borrego J, Kuki Á, Kéki S, Panyi G, Varga Z. Multiple mechanisms contribute to fluorometry signals from the voltage-gated proton channel. Commun Biol 2022; 5:1131. [PMID: 36289443 PMCID: PMC9606259 DOI: 10.1038/s42003-022-04065-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 09/30/2022] [Indexed: 11/30/2022] Open
Abstract
Voltage-clamp fluorometry (VCF) supplies information about the conformational changes of voltage-gated proteins. Changes in the fluorescence intensity of the dye attached to a part of the protein that undergoes a conformational rearrangement upon the alteration of the membrane potential by electrodes constitute the signal. The VCF signal is generated by quenching and dequenching of the fluorescence as the dye traverses various local environments. Here we studied the VCF signal generation, using the Hv1 voltage-gated proton channel as a tool, which shares a similar voltage-sensor structure with voltage-gated ion channels but lacks an ion-conducting pore. Using mutagenesis and lipids added to the extracellular solution we found that the signal is generated by the combined effects of lipids during movement of the dye relative to the plane of the membrane and by quenching amino acids. Our 3-state model recapitulates the VCF signals of the various mutants and is compatible with the accepted model of two major voltage-sensor movements. Fluorometry signals indicating conformational change in an ion channel are generated by quenching amino acids and lipid effects during movement of the dye relative to the plane of the membrane.
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Affiliation(s)
- Ferenc Papp
- grid.7122.60000 0001 1088 8582Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1, Debrecen, H-4032 Hungary
| | - Gilman E. S. Toombes
- grid.94365.3d0000 0001 2297 5165Molecular Physiology and Biophysics Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 35 Convent Dr., MSC 3701, Bethesda, MD 20892-3701 USA
| | - Zoltán Pethő
- grid.7122.60000 0001 1088 8582Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1, Debrecen, H-4032 Hungary ,grid.5949.10000 0001 2172 9288Institut für Physiologie II, Robert-Koch-Str. 27b, 48149 Münster, Germany
| | - Adrienn Bagosi
- grid.7122.60000 0001 1088 8582Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1, Debrecen, H-4032 Hungary
| | - Adam Feher
- grid.7122.60000 0001 1088 8582Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1, Debrecen, H-4032 Hungary
| | - János Almássy
- grid.7122.60000 0001 1088 8582Department of Physiology, Faculty of Medicine, University of Debrecen, Egyetem ter 1, Debrecen, H-4032 Hungary
| | - Jesús Borrego
- grid.7122.60000 0001 1088 8582Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1, Debrecen, H-4032 Hungary
| | - Ákos Kuki
- grid.7122.60000 0001 1088 8582Department of Applied Chemistry, University of Debrecen, Egyetem ter 1, Debrecen, H-4032 Hungary
| | - Sándor Kéki
- grid.7122.60000 0001 1088 8582Department of Applied Chemistry, University of Debrecen, Egyetem ter 1, Debrecen, H-4032 Hungary
| | - Gyorgy Panyi
- grid.7122.60000 0001 1088 8582Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1, Debrecen, H-4032 Hungary
| | - Zoltan Varga
- grid.7122.60000 0001 1088 8582Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Egyetem ter 1, Debrecen, H-4032 Hungary
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16
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Dib K, El Banna A, Radulescu C, Lopez Campos G, Sheehan G, Kavanagh K. Histamine Produced by Gram-Negative Bacteria Impairs Neutrophil's Antimicrobial Response by Engaging the Histamine 2 Receptor. J Innate Immun 2022; 15:153-173. [PMID: 35858582 PMCID: PMC10643892 DOI: 10.1159/000525536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 06/12/2022] [Indexed: 11/19/2022] Open
Abstract
We found that histamine (10-9 M) did not have any effect on the in vitro capture of Escherichia coli by neutrophils but accelerated its intracellular killing. In contrast, histamine (10-6 M) delayed the capture of Escherichia coli by neutrophils and reduced the amounts of pHrodo zymosan particles inside acidic mature phagosomes. Histamine acted through the H4R and the H2R, which are coupled to the Src family tyrosine kinases or the cAMP/protein kinase A pathway, respectively. The protein kinase A inhibitor H-89 abrogated the delay in bacterial capture induced by histamine (10-6 M) and the Src family tyrosine kinase inhibitor PP2 blocked histamine (10-9 M) induced acceleration of bacterial intracellular killing and tyrosine phosphorylation of proteins. To investigate the role of histamine in pathogenicity, we designed an Acinetobacter baumannii strain deficient in histamine production (hdc::TOPO). Galleria mellonella larvae inoculated with the wild-type Acinetobacter baumannii ATCC 17978 strain (1.1 × 105 CFU) died rapidly (100% death within 40 h) but not when inoculated with the Acinetobacter baumannii hdc::TOPO mutant (10% mortality). The concentration of histamine rose in the larval haemolymph upon inoculation of the wild type but not the Acinetobacter baumannii hdc::TOPO mutant, such concentration of histamine blocks the ability of hemocytes from Galleria mellonella to capture Candida albicans in vitro. Thus, bacteria-producing histamine, by maintaining high levels of histamine, may impair neutrophil phagocytosis by hijacking the H2R.
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Affiliation(s)
- Karim Dib
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Amal El Banna
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Clara Radulescu
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Guillermo Lopez Campos
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Gerard Sheehan
- Department of Biology, Maynooth University, Maynooth, Ireland
| | - Kevin Kavanagh
- Department of Biology, Maynooth University, Maynooth, Ireland
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17
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Oster L, Schröder J, Rugi M, Schimmelpfennig S, Sargin S, Schwab A, Najder K. Extracellular pH Controls Chemotaxis of Neutrophil Granulocytes by Regulating Leukotriene B 4 Production and Cdc42 Signaling. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 209:136-144. [PMID: 35715008 DOI: 10.4049/jimmunol.2100475] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 04/27/2022] [Indexed: 06/15/2023]
Abstract
Neutrophil granulocytes are the first and robust responders to the chemotactic molecules released from an inflamed acidic tissue. The aim of this study was to elucidate the role of microenvironmental pH in neutrophil chemotaxis. To this end, we used neutrophils from male C57BL/6J mice and combined live cell imaging chemotaxis assays with measurements of the intracellular pH (pHi) in varied extracellular pH (pHe). Observational studies were complemented by biochemical analyses of leukotriene B4 (LTB4) production and activation of the Cdc42 Rho GTPase. Our data show that pHi of neutrophils dose-dependently adapts to a given pH of the extracellular milieu. Neutrophil chemotaxis toward C5a has an optimum at pHi ∼7.1, and its pHi dependency is almost parallel to that of LTB4 production. Consequently, a shallow pHe gradient, resembling that encountered by neutrophils during extravasation from a blood vessel (pH ∼7.4) into the interstitium (pH ∼7.2), favors chemotaxis of stimulated neutrophils. Lowering pHe below pH 6.8, predominantly affects neutrophil chemotaxis, although the velocity is largely maintained. Inhibition of the Na+/H+ exchanger 1 (NHE1) with cariporide drastically attenuates neutrophil chemotaxis at the optimal pHi irrespective of the high LTB4 production. Neutrophil migration and chemotaxis are almost completely abrogated by inhibiting LTB4 production or blocking its receptor (BLT1). The abundance of the active GTP-bound form of Cdc42 is strongly reduced by NHE1 inhibition or pHe 6.5. In conclusion, we propose that the pH dependence of neutrophil chemotaxis toward C5a is caused by a pHi-dependent production of LTB4 and activation of Cdc42. Moreover, it requires the activity of NHE1.
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Affiliation(s)
- Leonie Oster
- Institute of Physiology II, Westfälische Wilhelms University, Münster, Germany
| | - Julia Schröder
- Institute of Physiology II, Westfälische Wilhelms University, Münster, Germany
| | - Micol Rugi
- Institute of Physiology II, Westfälische Wilhelms University, Münster, Germany
| | | | - Sarah Sargin
- Institute of Physiology II, Westfälische Wilhelms University, Münster, Germany
| | - Albrecht Schwab
- Institute of Physiology II, Westfälische Wilhelms University, Münster, Germany
| | - Karolina Najder
- Institute of Physiology II, Westfälische Wilhelms University, Münster, Germany
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18
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Jardin C, Ohlwein N, Franzen A, Chaves G, Musset B. The pH-dependent gating of the human voltage-gated proton channel from computational simulations. Phys Chem Chem Phys 2022; 24:9964-9977. [PMID: 35445675 DOI: 10.1039/d1cp05609c] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Gating of the voltage-gated proton channel HV1 is strongly controlled by pH. There is evidence that this involves the sidechains of titratable amino acids that change their protonation state with changes of the pH. Despite experimental investigations to identify the amino acids involved in pH sensing only few progress has been made, including one histidine at the cytoplasmic side of the channel that is involved in sensing cellular pH. We have used constant pH molecular dynamics simulations in symmetrical and asymmetrical pH conditions across the membrane to investigate the pH- and ΔpH-dependent gating of the human HV1 channel. Therefore, the pKa of every titratable amino acids has been assessed in single simulations. Our simulations captured initial conformational changes between a deactivated and an activated state of the channel induced solely by changes of the pH. The pH-dependent gating is accompanied by an outward displacement of the three S4 voltage sensing arginines that moves the second arginine past the hydrophobic gasket (HG) which separates the inner and outer pores of the channel. HV1 activation, when outer pH increases, involves amino acids at the extracellular entrance of the channel that extend the network of interactions from the external solution down to the HG. Whereas, amino acids at the cytoplasmic entrance of the channel are involved in activation, when inner pH decreases, and in a network of interactions that extend from the cytoplasm up to the HG.
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Affiliation(s)
- Christophe Jardin
- Klinikum Nürnberg Medical School, CPPB, Institute of Physiology, Pathophysiology and Biophysics, Nuremberg, Germany.
| | - Niklas Ohlwein
- Klinikum Nürnberg Medical School, CPPB, Institute of Physiology, Pathophysiology and Biophysics, Nuremberg, Germany. .,Klinik für Anästhesiologie und operative Intensivmedizin, Universitätklinik der Paracelsus Medizinischen Privatuniversität, Nuremberg, Germany
| | - Arne Franzen
- Institute of Biological Information Processing, Molecular and Cellular Physiology (IBI-1), Forschungszentrum Jülich, Jülich, Germany
| | - Gustavo Chaves
- Klinikum Nürnberg Medical School, CPPB, Institute of Physiology, Pathophysiology and Biophysics, Nuremberg, Germany.
| | - Boris Musset
- Klinikum Nürnberg Medical School, CPPB, Institute of Physiology, Pathophysiology and Biophysics, Nuremberg, Germany.
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19
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Wang G, Nauseef WM. Neutrophil dysfunction in the pathogenesis of cystic fibrosis. Blood 2022; 139:2622-2631. [PMID: 35213685 PMCID: PMC9053701 DOI: 10.1182/blood.2021014699] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 01/31/2022] [Indexed: 11/20/2022] Open
Abstract
Polymorphonuclear neutrophils (PMNs) figure prominently in host defense against infection and in noninfectious inflammation. Mobilized early in an inflammatory response, PMNs mediate immediate cellular defense against microbes and orchestrate events that culminate in cessation of inflammation and restoration of homeostasis. Failure to terminate the inflammatory response and its causes can fuel exuberant inflammation characteristic of many human diseases, including cystic fibrosis (CF), an autosomal recessive genetic disease caused by mutations in the CF transmembrane conductance regulator. CF affects multiple end organs, with persistent bacterial infection and chronic neutrophilic inflammation in airways predominating the clinical picture. To match the diverse microbial challenges that they may encounter, PMNs possess a variety of antimicrobial systems to slow or kill invading microorganisms confined in their phagosomes. Prominent among PMN defense systems is their ability to generate hypochlorous acid, a potent microbicide, by reacting oxidants generated by the NADPH oxidase with myeloperoxidase (MPO) released from azurophilic granules in the presence of chloride (Cl-). Products of the MPO-H2O2-Cl system oxidize susceptible biomolecules and support robust antimicrobial action against many, but not all, potential human pathogens. Underscoring that the MPO-H2O2-Cl system is integral to optimal host defense and proper regulation of inflammation, individuals with defects in any component of this system, as seen in chronic granulomatous disease or MPO deficiency, incur increased rates or severity of infection and signs of dysregulated inflammatory responses. We focus attention in this review on the molecular basis for and the clinical consequences of defects in the MPO-H2O2-Cl system because of the compromised Cl transport seen in CF. We will discuss first how the MPO-H2O2-Cl system in healthy PMNs participates in host defense and resolution of inflammation and then review how a defective MPO-H2O2-Cl system contributes to the increased susceptibility to infection and dysregulated inflammation associated with the clinical manifestations of CF.
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Affiliation(s)
- Guoshun Wang
- Department of Microbiology, Immunology, and Parasitology, and
- Department of Genetics, Louisiana State University Health Sciences Center, New Orleans, LA
| | - William M Nauseef
- Inflammation Program, Department of Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA; and
- Veterans Administration Medical Center, Iowa City, IA
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20
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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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21
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Inhibiting Hv1 channel in peripheral sensory neurons attenuates chronic inflammatory pain and opioid side effects. Cell Res 2022; 32:461-476. [PMID: 35115667 PMCID: PMC9061814 DOI: 10.1038/s41422-022-00616-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 01/04/2022] [Indexed: 02/05/2023] Open
Abstract
Both opioids and nonsteroidal anti-inflammatory drugs (NSAIDS) produce deleterious side effects and fail to provide sustained relief in patients with chronic inflammatory pain. Peripheral neuroinflammation (PN) is critical for initiation and development of inflammatory pain. A better understanding of molecular mechanisms underlying PN would facilitate the discovery of new analgesic targets and the development of new therapeutics. Emerging evidence suggests that peripheral sensory neurons are not only responders to painful stimuli, but are also actively engaged in inflammation and immunity, whereas the intrinsic regulatory mechanism is poorly understood. Here we report the expression of proton-selective ion channel Hv1 in peripheral sensory neurons in rodents and humans, which was previously shown as selectively expressed in microglia in mammalian central nervous system. Neuronal Hv1 was up-regulated by PN or depolarizing stimulation, which in turn aggravates inflammation and nociception. Inhibiting neuronal Hv1 genetically or by a newly discovered selective inhibitor YHV98-4 reduced intracellular alkalization and ROS production in inflammatory pain, mitigated the imbalance in downstream SHP-1-pAKT signaling, and also diminished pro-inflammatory chemokine release to alleviate nociception and morphine-induced hyperalgesia and tolerance. Thus, our data reveal neuronal Hv1 as a novel target in analgesia strategy and managing opioids-related side effects.
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22
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Heitzeneder S, Bosse KR, Zhu Z, Zhelev D, Majzner RG, Radosevich MT, Dhingra S, Sotillo E, Buongervino S, Pascual-Pasto G, Garrigan E, Xu P, Huang J, Salzer B, Delaidelli A, Raman S, Cui H, Martinez B, Bornheimer SJ, Sahaf B, Alag A, Fetahu IS, Hasselblatt M, Parker KR, Anbunathan H, Hwang J, Huang M, Sakamoto K, Lacayo NJ, Klysz DD, Theruvath J, Vilches-Moure JG, Satpathy AT, Chang HY, Lehner M, Taschner-Mandl S, Julien JP, Sorensen PH, Dimitrov DS, Maris JM, Mackall CL. GPC2-CAR T cells tuned for low antigen density mediate potent activity against neuroblastoma without toxicity. Cancer Cell 2022; 40:53-69.e9. [PMID: 34971569 PMCID: PMC9092726 DOI: 10.1016/j.ccell.2021.12.005] [Citation(s) in RCA: 61] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 10/13/2021] [Accepted: 12/06/2021] [Indexed: 01/12/2023]
Abstract
Pediatric cancers often mimic fetal tissues and express proteins normally silenced postnatally that could serve as immune targets. We developed T cells expressing chimeric antigen receptors (CARs) targeting glypican-2 (GPC2), a fetal antigen expressed on neuroblastoma (NB) and several other solid tumors. CARs engineered using standard designs control NBs with transgenic GPC2 overexpression, but not those expressing clinically relevant GPC2 site density (∼5,000 molecules/cell, range 1-6 × 103). Iterative engineering of transmembrane (TM) and co-stimulatory domains plus overexpression of c-Jun lowered the GPC2-CAR antigen density threshold, enabling potent and durable eradication of NBs expressing clinically relevant GPC2 antigen density, without toxicity. These studies highlight the critical interplay between CAR design and antigen density threshold, demonstrate potent efficacy and safety of a lead GPC2-CAR candidate suitable for clinical testing, and credential oncofetal antigens as a promising class of targets for CAR T cell therapy of solid tumors.
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Affiliation(s)
- Sabine Heitzeneder
- Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Lorry Lokey Building, Suite G3141, MC: 5456, 265 Campus Drive, Stanford, CA 94305, USA
| | - Kristopher R Bosse
- Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zhongyu Zhu
- National Cancer Institute, Frederick, MD 21702, USA
| | - Doncho Zhelev
- University of Pittsburgh Department of Medicine, Pittsburgh, PA 15261, USA
| | - Robbie G Majzner
- Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Lorry Lokey Building, Suite G3141, MC: 5456, 265 Campus Drive, Stanford, CA 94305, USA
| | - Molly T Radosevich
- Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Lorry Lokey Building, Suite G3141, MC: 5456, 265 Campus Drive, Stanford, CA 94305, USA
| | - Shaurya Dhingra
- Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Lorry Lokey Building, Suite G3141, MC: 5456, 265 Campus Drive, Stanford, CA 94305, USA
| | - Elena Sotillo
- Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Lorry Lokey Building, Suite G3141, MC: 5456, 265 Campus Drive, Stanford, CA 94305, USA
| | - Samantha Buongervino
- Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Guillem Pascual-Pasto
- Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Emily Garrigan
- Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Peng Xu
- Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Lorry Lokey Building, Suite G3141, MC: 5456, 265 Campus Drive, Stanford, CA 94305, USA
| | - Jing Huang
- Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Lorry Lokey Building, Suite G3141, MC: 5456, 265 Campus Drive, Stanford, CA 94305, USA
| | - Benjamin Salzer
- St. Anna Children's Cancer Research Institute, Vienna, Austria; Christian Doppler Laboratory for Next Generation CAR T Cells, Vienna, Austria
| | - Alberto Delaidelli
- Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, BC V5Z 1L3, Canada
| | - Swetha Raman
- Program in Molecular Medicine, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Hong Cui
- Program in Molecular Medicine, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Benjamin Martinez
- Program in Molecular Medicine, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | | | - Bita Sahaf
- Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Lorry Lokey Building, Suite G3141, MC: 5456, 265 Campus Drive, Stanford, CA 94305, USA
| | - Anya Alag
- Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Lorry Lokey Building, Suite G3141, MC: 5456, 265 Campus Drive, Stanford, CA 94305, USA
| | - Irfete S Fetahu
- University of Pittsburgh Department of Medicine, Pittsburgh, PA 15261, USA
| | - Martin Hasselblatt
- Institute of Neuropathology, University Hospital Münster, Münster, Germany
| | - Kevin R Parker
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA 94305, USA
| | - Hima Anbunathan
- Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Lorry Lokey Building, Suite G3141, MC: 5456, 265 Campus Drive, Stanford, CA 94305, USA
| | | | - Min Huang
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Kathleen Sakamoto
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Norman J Lacayo
- Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Dorota D Klysz
- Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Lorry Lokey Building, Suite G3141, MC: 5456, 265 Campus Drive, Stanford, CA 94305, USA
| | - Johanna Theruvath
- Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Lorry Lokey Building, Suite G3141, MC: 5456, 265 Campus Drive, Stanford, CA 94305, USA
| | - José G Vilches-Moure
- Department of Comparative Medicine, Animal Histology Services, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ansuman T Satpathy
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes, Stanford University, Stanford, CA 94305, USA; Parker Institute for Cancer Immunotherapy, San Francisco, CA 941209, USA; Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305, USA
| | - Manfred Lehner
- St. Anna Children's Cancer Research Institute, Vienna, Austria; Christian Doppler Laboratory for Next Generation CAR T Cells, Vienna, Austria
| | | | - Jean-Phillipe Julien
- Program in Molecular Medicine, Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada; Departments of Biochemistry and Immunology, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Poul H Sorensen
- Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, BC V5Z 1L3, Canada
| | - Dimiter S Dimitrov
- University of Pittsburgh Department of Medicine, Pittsburgh, PA 15261, USA
| | - John M Maris
- Children's Hospital of Philadelphia and Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Crystal L Mackall
- Center for Cancer Cell Therapy, Stanford Cancer Institute, Stanford University School of Medicine, Lorry Lokey Building, Suite G3141, MC: 5456, 265 Campus Drive, Stanford, CA 94305, USA; Department of Pediatrics, Stanford University School of Medicine, Stanford, CA 94305, USA; Parker Institute for Cancer Immunotherapy, San Francisco, CA 941209, USA; Department of Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
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23
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Teng B, Kaplan JP, Liang Z, Krieger Z, Tu YH, Burendei B, Ward AB, Liman ER. Structural motifs for subtype-specific pH-sensitive gating of vertebrate otopetrin proton channels. eLife 2022; 11:77946. [PMID: 35920807 PMCID: PMC9348849 DOI: 10.7554/elife.77946] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 07/19/2022] [Indexed: 01/05/2023] Open
Abstract
Otopetrin (OTOP) channels are proton-selective ion channels conserved among vertebrates and invertebrates, with no structural similarity to other ion channels. There are three vertebrate OTOP channels (OTOP1, OTOP2, and OTOP3), of which one (OTOP1) functions as a sour taste receptor. Whether extracellular protons gate OTOP channels, in addition to permeating them, was not known. Here, we compare the functional properties of the three murine OTOP channels using patch-clamp recording and cytosolic pH microfluorimetry. We find that OTOP1 and OTOP3 are both steeply activated by extracellular protons, with thresholds of pHo <6.0 and 5.5, respectively, and kinetics that are pH-dependent. In contrast, OTOP2 channels are broadly active over a large pH range (pH 5 pH 10) and carry outward currents in response to extracellular alkalinization (>pH 9.0). Strikingly, we could change the pH-sensitive gating of OTOP2 and OTOP3 channels by swapping extracellular linkers that connect transmembrane domains. Swaps of extracellular linkers in the N domain, comprising transmembrane domains 1-6, tended to change the relative conductance at alkaline pH of chimeric channels, while swaps within the C domain, containing transmembrane domains 7-12, tended to change the rates of OTOP3 current activation. We conclude that members of the OTOP channel family are proton-gated (acid-sensitive) proton channels and that the gating apparatus is distributed across multiple extracellular regions within both the N and C domains of the channels. In addition to the taste system, OTOP channels are expressed in the vertebrate vestibular and digestive systems. The distinct gating properties we describe may allow them to subserve varying cell-type specific functions in these and other biological systems.
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Affiliation(s)
- Bochuan Teng
- Section of Neurobiology, Department of Biological Sciences, University of Southern CaliforniaLos AngelesUnited States,Program in Neuroscience, University of Southern CaliforniaLos AngelesUnited States
| | - Joshua P Kaplan
- Section of Neurobiology, Department of Biological Sciences, University of Southern CaliforniaLos AngelesUnited States,Program in Neuroscience, University of Southern CaliforniaLos AngelesUnited States
| | - Ziyu Liang
- Section of Neurobiology, Department of Biological Sciences, University of Southern CaliforniaLos AngelesUnited States,Program in Neuroscience, University of Southern CaliforniaLos AngelesUnited States
| | - Zachary Krieger
- Section of Neurobiology, Department of Biological Sciences, University of Southern CaliforniaLos AngelesUnited States
| | - Yu-Hsiang Tu
- Diabetes, Endocrinology, and Obesity Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of HealthBethesdaUnited States
| | - Batuujin Burendei
- Department of Integrative Structural and Computational Biology, The Scripps Research InstituteLa JollaUnited States
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, The Scripps Research InstituteLa JollaUnited States
| | - Emily R Liman
- Section of Neurobiology, Department of Biological Sciences, University of Southern CaliforniaLos AngelesUnited States,Program in Neuroscience, University of Southern CaliforniaLos AngelesUnited States
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24
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Stratmann AEP, Wohlgemuth L, Erber ME, Bernhard S, Hug S, Fauler M, Vidoni L, Mohamed AOK, Thomaß BD, Münnich F, Stukan L, Föhr KJ, Mannes M, Huber-Lang MS, Messerer DAC. Simultaneous Measurement of Changes in Neutrophil Granulocyte Membrane Potential, Intracellular pH, and Cell Size by Multiparametric Flow Cytometry. Biomedicines 2021; 9:1504. [PMID: 34829733 PMCID: PMC8614908 DOI: 10.3390/biomedicines9111504] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 10/14/2021] [Accepted: 10/18/2021] [Indexed: 01/10/2023] Open
Abstract
Neutrophils provide rapid and efficient defense mechanisms against invading pathogens. Upon stimulation with proinflammatory mediators, including complement factors and bacterial peptides, neutrophils respond with changes in their membrane potential, intracellular pH, and cellular size. This study provides an approach to quantify these important changes simultaneously using multiparametric flow cytometry, thereby revealing a typical sequence of neutrophil activation consisting of depolarization, alkalization, and increase in cellular size. Additionally, the time resolution of the flow cytometric measurement is improved in order to allow changes that occur within seconds to be monitored, and thus to enhance the kinetic analysis of the neutrophil response. The method is appropriate for the reliable semiquantitative detection of small variations with respect to an increase, no change, and decrease in those parameters as demonstrated by the screening of various proinflammatory mediators. As a translational outlook, the findings are put into context in inflammatory conditions in vitro as well as in a clinically relevant whole blood model of endotoxemia. Taken together, the multiparametric analysis of neutrophil responsiveness regarding depolarization, alkalization, and changes in cellular size may contribute to a better understanding of neutrophils in health and disease, thus potentially yielding innovative mechanistic insights and possible novel diagnostic and/or prognostic approaches.
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Affiliation(s)
| | - Lisa Wohlgemuth
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Maike Elisabeth Erber
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Stefan Bernhard
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Stefan Hug
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Michael Fauler
- Institute of General Physiology, Ulm University, 89081 Ulm, Germany
| | - Laura Vidoni
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Adam Omar Khalaf Mohamed
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Bertram Dietrich Thomaß
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Frederik Münnich
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Laura Stukan
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Ulm, 89081 Ulm, Germany
| | - Karl Josef Föhr
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Ulm, 89081 Ulm, Germany
| | - Marco Mannes
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - Markus Stefan Huber-Lang
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
| | - David Alexander Christian Messerer
- Institute of Clinical and Experimental Trauma Immunology, University Hospital Ulm, 89081 Ulm, Germany
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Ulm, 89081 Ulm, Germany
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25
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Taylor JP, Tse HM. The role of NADPH oxidases in infectious and inflammatory diseases. Redox Biol 2021; 48:102159. [PMID: 34627721 PMCID: PMC8487856 DOI: 10.1016/j.redox.2021.102159] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/30/2021] [Accepted: 09/30/2021] [Indexed: 02/06/2023] Open
Abstract
Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOX) are enzymes that generate superoxide or hydrogen peroxide from molecular oxygen utilizing NADPH as an electron donor. There are seven enzymes in the NOX family: NOX1-5 and dual oxidase (DUOX) 1-2. NOX enzymes in humans play important roles in diverse biological functions and vary in expression from tissue to tissue. Importantly, NOX2 is involved in regulating many aspects of innate and adaptive immunity, including regulation of type I interferons, the inflammasome, phagocytosis, antigen processing and presentation, and cell signaling. DUOX1 and DUOX2 play important roles in innate immune defenses at epithelial barriers. This review discusses the role of NOX enzymes in normal physiological processes as well as in disease. NOX enzymes are important in autoimmune diseases like type 1 diabetes and have also been implicated in acute lung injury caused by infection with SARS-CoV-2. Targeting NOX enzymes directly or through scavenging free radicals may be useful therapies for autoimmunity and acute lung injury where oxidative stress contributes to pathology.
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Affiliation(s)
- Jared P Taylor
- Department of Microbiology, Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hubert M Tse
- Department of Microbiology, Comprehensive Diabetes Center, University of Alabama at Birmingham, Birmingham, AL, USA.
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26
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Droste A, Chaves G, Stein S, Trzmiel A, Schweizer M, Karl H, Musset B. Zinc accelerates respiratory burst termination in human PMN. Redox Biol 2021; 47:102133. [PMID: 34562872 PMCID: PMC8476447 DOI: 10.1016/j.redox.2021.102133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/09/2021] [Accepted: 09/12/2021] [Indexed: 11/25/2022] Open
Abstract
The respiratory burst of phagocytes is essential for human survival. Innate immune defence against pathogens relies strongly on reactive oxygen species (ROS) production by the NADPH oxidase (NOX2). ROS kill pathogens while the translocation of electrons across the plasma membrane via NOX2 depolarizes the cell. Simultaneously, protons are released into the cytosol. Here, we compare freshly isolated human polymorphonuclear leukocytes (PMN) to the granulocytes-like cell line PLB 985. We are recording ROS production while inhibiting the charge compensating and pH regulating voltage-gated proton channel (HV1). The data suggests that human PMN and the PLB 985 generate ROS via a general mechanism, consistent of NOX2 and HV1. Additionally, we advanced a mathematical model based on the biophysical properties of NOX2 and HV1. Our results strongly suggest the essential interconnection of HV1 and NOX2 during the respiratory burst of phagocytes. Zinc chelation during the time course of the experiments postulates that zinc leads to an irreversible termination of the respiratory burst over time. Flow cytometry shows cell death triggered by high zinc concentrations and PMA. Our data might help to elucidate the complex interaction of proteins during the respiratory burst and contribute to decipher its termination.
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Affiliation(s)
- Annika Droste
- Center of Physiology, Pathophysiology and Biophysics, Paracelsus Medical University, Nuremberg, Germany; Department of Gynecology and Obstetrics, Johannes Gutenberg University, Mainz, Germany
| | - Gustavo Chaves
- Center of Physiology, Pathophysiology and Biophysics, Paracelsus Medical University, Nuremberg, Germany
| | - Stefan Stein
- Flow Cytometry Unit, Institute for Tumor Biology and Experimental Therapy, Georg-Speyer-Haus, Frankfurt, Germany
| | - Annette Trzmiel
- Flow Cytometry Unit, Institute for Tumor Biology and Experimental Therapy, Georg-Speyer-Haus, Frankfurt, Germany
| | - Matthias Schweizer
- Federal Institute for Vaccines and Biomedicines, Paul-Ehrlich-Institut, Langen, Germany
| | - Hubert Karl
- Department efi, Technische Hochschule Nürnberg Georg Simon Ohm, Nuremberg, Germany
| | - Boris Musset
- Center of Physiology, Pathophysiology and Biophysics, Paracelsus Medical University, Nuremberg, Germany; Center of Physiology, Pathophysiology and Biophysics, Paracelsus Medical University, Salzburg, Austria.
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27
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Geng L, Zhao J, Deng Y, Molano I, Xu X, Xu L, Ruiz P, Li Q, Feng X, Zhang M, Tan W, Kamen DL, Bae SC, Gilkeson GS, Sun L, Tsao BP. Human SLE variant NCF1-R90H promotes kidney damage and murine lupus through enhanced Tfh2 responses induced by defective efferocytosis of macrophages. Ann Rheum Dis 2021; 81:255-267. [PMID: 34556485 DOI: 10.1136/annrheumdis-2021-220793] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 09/01/2021] [Indexed: 12/15/2022]
Abstract
OBJECTIVES We previously identified a hypomorphic variant, p.Arg90His (p.R90H) of neutrophil cytosolic factor 1 (NCF1, a regulatory subunit of phagocyte nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 complex), as an putative causal variant for systemic lupus erythematosus (SLE), and established a knock-in (KI) H90 variant in the C57BL/6 background to study how this variant promotes lupus development. METHODS Wild type (WT) and KI littermates were assessed for immune profiles and lupus-like features. Disease activity and renal damage of patients with SLE were assessed by systemic lupus erythematosus disease activity index (SLEDAI) and renal items of systemic lupus international collaborating clinics (SLICC), respectively. RESULTS Compared with WT littermates, 5-week-old homozygous KI mice had reduced oxidative burst, splenomegaly, elevated type I interferon (IFN-I) scores, increased ratios of splenic follicular T helper 2 (Tfh2) to either T follicular regulatory (Tfr) or Tfh1 cells, increased ANA+ follicular, germinal centre and plasma cells without spontaneous kidney disease up to 1 year of age. Pristane treatment exacerbated the immune dysregulation and induced IFN-I-dependent kidney disease in 36-week-old H90 KI female mice. Decreased efferocytosis of macrophages derived from KI mice and patients with homozygous H90 SLE promoted elevated ratios of Tfh2/Tfr and Tfh2/Tfh1 as well as dysregulated humoral responses due to reduced voltage-gated proton channel 1 (Hv1)-dependent acidification of phagosome pH to neutralise the decreased electrogenic effect of the H90 variant, resulting in impaired maturation and phagosome proteolysis, and increased autoantibody production and kidney damage in mice and patients with SLE of multiple ancestries. CONCLUSIONS A lupus causal variant, NCF1-H90, reduces macrophage efferocytosis, enhances Tfh2 responses and promotes autoantibody production and kidney damage in both mice and patients with SLE.
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Affiliation(s)
- Linyu Geng
- Division of Rheumatology and Immunology, Medical University of South Carolina, Charleston, South Carolina, USA.,Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Jian Zhao
- Division of Rheumatology and Immunology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Yun Deng
- Division of Rheumatology and Immunology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Ivan Molano
- Division of Rheumatology and Immunology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Xue Xu
- Division of Rheumatology and Immunology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Lingxiao Xu
- Division of Rheumatology and Immunology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Phillip Ruiz
- Department of Surgery, University of Miami School of Medicine, Miami, Florida, USA
| | - Quanzhen Li
- Department of Immunology and Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Xuebing Feng
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Miaojia Zhang
- Department of Rheumatology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Wenfeng Tan
- Department of Rheumatology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
| | - Diane L Kamen
- Division of Rheumatology and Immunology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Sang-Cheol Bae
- Department of Rheumatology, Hanyang University Hospital for Rheumatic Diseases and Hanyang University Institute for Rheumatology, Seoul, The Republic of Korea
| | - Gary S Gilkeson
- Division of Rheumatology and Immunology, Medical University of South Carolina, Charleston, South Carolina, USA.,Ralph H Johnson VA Medical Center, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Lingyun Sun
- Department of Rheumatology and Immunology, The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Betty P Tsao
- Division of Rheumatology and Immunology, Medical University of South Carolina, Charleston, South Carolina, USA
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28
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Ion Channels, Transporters, and Sensors Interact with the Acidic Tumor Microenvironment to Modify Cancer Progression. Rev Physiol Biochem Pharmacol 2021; 182:39-84. [PMID: 34291319 DOI: 10.1007/112_2021_63] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Solid tumors, including breast carcinomas, are heterogeneous but typically characterized by elevated cellular turnover and metabolism, diffusion limitations based on the complex tumor architecture, and abnormal intra- and extracellular ion compositions particularly as regards acid-base equivalents. Carcinogenesis-related alterations in expression and function of ion channels and transporters, cellular energy levels, and organellar H+ sequestration further modify the acid-base composition within tumors and influence cancer cell functions, including cell proliferation, migration, and survival. Cancer cells defend their cytosolic pH and HCO3- concentrations better than normal cells when challenged with the marked deviations in extracellular H+, HCO3-, and lactate concentrations typical of the tumor microenvironment. Ionic gradients determine the driving forces for ion transporters and channels and influence the membrane potential. Cancer and stromal cells also sense abnormal ion concentrations via intra- and extracellular receptors that modify cancer progression and prognosis. With emphasis on breast cancer, the current review first addresses the altered ion composition and the changes in expression and functional activity of ion channels and transporters in solid cancer tissue. It then discusses how ion channels, transporters, and cellular sensors under influence of the acidic tumor microenvironment shape cancer development and progression and affect the potential of cancer therapies.
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29
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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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30
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Zhao R, Dai H, Arias RJ, De Blas GA, Orta G, Pavarotti MA, Shen R, Perozo E, Mayorga LS, Darszon A, Goldstein SAN. Direct activation of the proton channel by albumin leads to human sperm capacitation and sustained release of inflammatory mediators by neutrophils. Nat Commun 2021; 12:3855. [PMID: 34158477 PMCID: PMC8219737 DOI: 10.1038/s41467-021-24145-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 06/02/2021] [Indexed: 02/05/2023] Open
Abstract
Human voltage-gated proton channels (hHv1) extrude protons from cells to compensate for charge and osmotic imbalances due metabolism, normalizing intracellular pH and regulating protein function. Human albumin (Alb), present at various levels throughout the body, regulates oncotic pressure and transports ligands. Here, we report Alb is required to activate hHv1 in sperm and neutrophils. Dose-response studies reveal the concentration of Alb in semen is too low to activate hHv1 in sperm whereas the higher level in uterine fluid yields proton efflux, allowing capacitation, the acrosomal reaction, and oocyte fertilization. Likewise, Alb activation of hHv1 in neutrophils is required to sustain production and release of reactive oxygen species during the immune respiratory burst. One Alb binds to both voltage sensor domains (VSDs) in hHv1, enhancing open probability and increasing proton current. A computational model of the Alb-hHv1 complex, validated by experiments, identifies two sites in Alb domain II that interact with the VSDs, suggesting an electrostatic gating modification mechanism favoring the active "up" sensor conformation. This report shows how sperm are triggered to fertilize, resolving how hHv1 opens at negative membrane potentials in sperm, and describes a role for Alb in physiology that will operate in the many tissues expressing hHv1.
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Affiliation(s)
- Ruiming Zhao
- Departments of Pediatrics and Physiology & Biophysics, Susan and Henry Samueli College of Health Sciences, University of California, Irvine, CA, USA
| | - Hui Dai
- Departments of Pediatrics and Physiology & Biophysics, Susan and Henry Samueli College of Health Sciences, University of California, Irvine, CA, USA
| | - Rodolfo J Arias
- Instituto de Histología y Embriología de Mendoza (IHEM/CONICET-UNCuyo), School of Medicine, National University of Cuyo, Mendoza, CP, Argentina
| | - Gerardo A De Blas
- Instituto de Histología y Embriología de Mendoza (IHEM/CONICET-UNCuyo), School of Medicine, National University of Cuyo, Mendoza, CP, Argentina
- Laboratorio de Telediagnóstico e Investigación Traslacional (LaTIT). Área de Farmacología. Departamento de Patología, School of Medicine, National University of Cuyo, Mendoza, CP, Argentina
| | - Gerardo Orta
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos, México
| | - Martín A Pavarotti
- Instituto de Histología y Embriología de Mendoza (IHEM/CONICET-UNCuyo), School of Medicine, National University of Cuyo, Mendoza, CP, Argentina
| | - Rong Shen
- Department of Biochemistry and Molecular Biology, Gordon Center for Integrative Science, University of Chicago, Chicago, IL, USA
| | - Eduardo Perozo
- Department of Biochemistry and Molecular Biology, Gordon Center for Integrative Science, University of Chicago, Chicago, IL, USA
| | - Luis S Mayorga
- Instituto de Histología y Embriología de Mendoza (IHEM/CONICET-UNCuyo), School of Medicine, National University of Cuyo, Mendoza, CP, Argentina
| | - Alberto Darszon
- Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Morelos, México
| | - Steve A N Goldstein
- Departments of Pediatrics and Physiology & Biophysics, Susan and Henry Samueli College of Health Sciences, University of California, Irvine, CA, USA.
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Vermot A, Petit-Härtlein I, Smith SME, Fieschi F. NADPH Oxidases (NOX): An Overview from Discovery, Molecular Mechanisms to Physiology and Pathology. Antioxidants (Basel) 2021; 10:890. [PMID: 34205998 PMCID: PMC8228183 DOI: 10.3390/antiox10060890] [Citation(s) in RCA: 227] [Impact Index Per Article: 75.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/21/2021] [Accepted: 05/26/2021] [Indexed: 01/17/2023] Open
Abstract
The reactive oxygen species (ROS)-producing enzyme NADPH oxidase (NOX) was first identified in the membrane of phagocytic cells. For many years, its only known role was in immune defense, where its ROS production leads to the destruction of pathogens by the immune cells. NOX from phagocytes catalyzes, via one-electron trans-membrane transfer to molecular oxygen, the production of the superoxide anion. Over the years, six human homologs of the catalytic subunit of the phagocyte NADPH oxidase were found: NOX1, NOX3, NOX4, NOX5, DUOX1, and DUOX2. Together with the NOX2/gp91phox component present in the phagocyte NADPH oxidase assembly itself, the homologs are now referred to as the NOX family of NADPH oxidases. NOX are complex multidomain proteins with varying requirements for assembly with combinations of other proteins for activity. The recent structural insights acquired on both prokaryotic and eukaryotic NOX open new perspectives for the understanding of the molecular mechanisms inherent to NOX regulation and ROS production (superoxide or hydrogen peroxide). This new structural information will certainly inform new investigations of human disease. As specialized ROS producers, NOX enzymes participate in numerous crucial physiological processes, including host defense, the post-translational processing of proteins, cellular signaling, regulation of gene expression, and cell differentiation. These diversities of physiological context will be discussed in this review. We also discuss NOX misregulation, which can contribute to a wide range of severe pathologies, such as atherosclerosis, hypertension, diabetic nephropathy, lung fibrosis, cancer, or neurodegenerative diseases, giving this family of membrane proteins a strong therapeutic interest.
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Affiliation(s)
- Annelise Vermot
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale, 38000 Grenoble, France; (A.V.); (I.P.-H.)
| | - Isabelle Petit-Härtlein
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale, 38000 Grenoble, France; (A.V.); (I.P.-H.)
| | - Susan M. E. Smith
- Department of Molecular and Cellular Biology, Kennesaw State University, Kennesaw, GA 30144, USA;
| | - Franck Fieschi
- Univ. Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale, 38000 Grenoble, France; (A.V.); (I.P.-H.)
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Perelman SS, James DBA, Boguslawski KM, Nelson CW, Ilmain JK, Zwack EE, Prescott RA, Mohamed A, Tam K, Chan R, Narechania A, Pawline MB, Vozhilla N, Moustafa AM, Kim SY, Dittmann M, Ekiert DC, Bhabha G, Shopsin B, Planet PJ, Koralov SB, Torres VJ. Genetic variation of staphylococcal LukAB toxin determines receptor tropism. Nat Microbiol 2021; 6:731-745. [PMID: 33875847 PMCID: PMC8597016 DOI: 10.1038/s41564-021-00890-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 03/11/2021] [Indexed: 02/02/2023]
Abstract
Staphylococcus aureus has evolved into diverse lineages, known as clonal complexes (CCs), which exhibit differences in the coding sequences of core virulence factors. Whether these alterations affect functionality is poorly understood. Here, we studied the highly polymorphic pore-forming toxin LukAB. We discovered that the LukAB toxin variants produced by S. aureus CC30 and CC45 kill human phagocytes regardless of whether CD11b, the previously established LukAB receptor, is present, and instead target the human hydrogen voltage-gated channel 1 (HVCN1). Biochemical studies identified the domain within human HVCN1 that drives LukAB species specificity, enabling the generation of humanized HVCN1 mice with enhanced susceptibility to CC30 LukAB and to bloodstream infection caused by CC30 S. aureus strains. Together, this work advances our understanding of an important S. aureus toxin and underscores the importance of considering genetic variation in characterizing virulence factors and understanding the tug of war between pathogens and the host.
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Affiliation(s)
- Sofya S Perelman
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - David B A James
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Kristina M Boguslawski
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Chase W Nelson
- Institute for Comparative Genomics, American Museum of Natural History, New York, NY, USA
- Biodiversity Research Center, Academia Sinica, Taipei, Taiwan
| | - Juliana K Ilmain
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Erin E Zwack
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Rachel A Prescott
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Adil Mohamed
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Kayan Tam
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Rita Chan
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Apurva Narechania
- Institute for Comparative Genomics, American Museum of Natural History, New York, NY, USA
| | - Miranda B Pawline
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
- Department of Medicine, Division of Infectious Diseases, New York University Grossman School of Medicine, New York, NY, USA
| | - Nikollaq Vozhilla
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Ahmed M Moustafa
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Sang Y Kim
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
- Office of Collaborative Sciences, NYU Grossman School of Medicine, New York, NY, USA
| | - Meike Dittmann
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
| | - Damian C Ekiert
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, USA
| | - Gira Bhabha
- Skirball Institute of Biomolecular Medicine and Department of Cell Biology, New York University Grossman School of Medicine, New York, NY, USA
| | - Bo Shopsin
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA
- Department of Medicine, Division of Infectious Diseases, New York University Grossman School of Medicine, New York, NY, USA
| | - Paul J Planet
- Institute for Comparative Genomics, American Museum of Natural History, New York, NY, USA
- Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sergei B Koralov
- Department of Pathology, New York University Grossman School of Medicine, New York, NY, USA
| | - Victor J Torres
- Department of Microbiology, New York University Grossman School of Medicine, New York, NY, USA.
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33
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Okochi Y, Okamura Y. Regulation of Neutrophil Functions by Hv1/VSOP Voltage-Gated Proton Channels. Int J Mol Sci 2021; 22:ijms22052620. [PMID: 33807711 PMCID: PMC7961965 DOI: 10.3390/ijms22052620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/25/2021] [Accepted: 03/01/2021] [Indexed: 12/15/2022] Open
Abstract
The voltage-gated proton channel, Hv1, also termed VSOP, was discovered in 2006. It has long been suggested that proton transport through voltage-gated proton channels regulate reactive oxygen species (ROS) production in phagocytes by counteracting the charge imbalance caused by the activation of NADPH oxidase. Discovery of Hv1/VSOP not only confirmed this process in phagocytes, but also led to the elucidation of novel functions in phagocytes. The compensation of charge by Hv1/VSOP sustains ROS production and is also crucial for promoting Ca2+ influx at the plasma membrane. In addition, proton extrusion into neutrophil phagosomes by Hv1/VSOP is necessary to maintain neutral phagosomal pH for the effective killing of bacteria. Contrary to the function of Hv1/VSOP as a positive regulator for ROS generation, it has been revealed that Hv1/VSOP also acts to inhibit ROS production in neutrophils. Hv1/VSOP inhibits hypochlorous acid production by regulating degranulation, leading to reduced inflammation upon fungal infection, and suppresses the activation of extracellular signal-regulated kinase (ERK) signaling by inhibiting ROS production. Thus, Hv1/VSOP is a two-way player regulating ROS production. Here, we review the functions of Hv1/VSOP in neutrophils and discuss future perspectives.
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Affiliation(s)
- Yoshifumi Okochi
- Integrative Physiology, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita 5650871, Osaka, Japan;
- Correspondence:
| | - Yasushi Okamura
- Integrative Physiology, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita 5650871, Osaka, Japan;
- Graduate School of Frontier Bioscience, Osaka University, 2-2 Yamada-oka, Suita 5650871, Osaka, Japan
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34
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Messerer DAC, Schmidt H, Frick M, Huber-Lang M. Ion and Water Transport in Neutrophil Granulocytes and Its Impairment during Sepsis. Int J Mol Sci 2021; 22:1699. [PMID: 33567720 PMCID: PMC7914618 DOI: 10.3390/ijms22041699] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/30/2021] [Accepted: 02/01/2021] [Indexed: 12/11/2022] Open
Abstract
Neutrophil granulocytes are the vanguard of innate immunity in response to numerous pathogens. Their activity drives the clearance of microbe- and damage-associated molecular patterns, thereby contributing substantially to the resolution of inflammation. However, excessive stimulation during sepsis leads to cellular unresponsiveness, immunological dysfunction, bacterial expansion, and subsequent multiple organ dysfunction. During the short lifespan of neutrophils, they can become significantly activated by complement factors, cytokines, and other inflammatory mediators. Following stimulation, the cells respond with a defined (electro-)physiological pattern, including depolarization, calcium influx, and alkalization as well as with increased metabolic activity and polarization of the actin cytoskeleton. Activity of ion transport proteins and aquaporins is critical for multiple cellular functions of innate immune cells, including chemotaxis, generation of reactive oxygen species, and phagocytosis of both pathogens and tissue debris. In this review, we first describe the ion transport proteins and aquaporins involved in the neutrophil ion-water fluxes in response to chemoattractants. We then relate ion and water flux to cellular functions with a focus on danger sensing, chemotaxis, phagocytosis, and oxidative burst and approach the role of altered ion transport protein expression and activity in impaired cellular functions and cell death during systemic inflammation as in sepsis.
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Affiliation(s)
- David Alexander Christian Messerer
- Institute of Clinical and Experimental Trauma-Immunology, University Hospital of Ulm, 89081 Ulm, Germany;
- Department of Anesthesiology and Intensive Care Medicine, University Hospital of Ulm, 89081 Ulm, Germany
| | - Hanna Schmidt
- Institute of General Physiology, Ulm University, 89081 Ulm, Germany; (H.S.); (M.F.)
- Department of Pediatrics and Adolescent Medicine, University Hospital of Ulm, 89081 Ulm, Germany
| | - Manfred Frick
- Institute of General Physiology, Ulm University, 89081 Ulm, Germany; (H.S.); (M.F.)
| | - Markus Huber-Lang
- Institute of Clinical and Experimental Trauma-Immunology, University Hospital of Ulm, 89081 Ulm, Germany;
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35
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Quade BN, Parker MD, Occhipinti R. The therapeutic importance of acid-base balance. Biochem Pharmacol 2021; 183:114278. [PMID: 33039418 PMCID: PMC7544731 DOI: 10.1016/j.bcp.2020.114278] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 10/06/2020] [Indexed: 02/06/2023]
Abstract
Baking soda and vinegar have been used as home remedies for generations and today we are only a mouse-click away from claims that baking soda, lemon juice, and apple cider vinegar are miracles cures for everything from cancer to COVID-19. Despite these specious claims, the therapeutic value of controlling acid-base balance is indisputable and is the basis of Food and Drug Administration-approved treatments for constipation, epilepsy, metabolic acidosis, and peptic ulcers. In this narrative review, we present evidence in support of the current and potential therapeutic value of countering local and systemic acid-base imbalances, several of which do in fact involve the administration of baking soda (sodium bicarbonate). Furthermore, we discuss the side effects of pharmaceuticals on acid-base balance as well as the influence of acid-base status on the pharmacokinetic properties of drugs. Our review considers all major organ systems as well as information relevant to several clinical specialties such as anesthesiology, infectious disease, oncology, dentistry, and surgery.
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Affiliation(s)
- Bianca N Quade
- Department of Physiology and Biophysics, The State University of New York, The University at Buffalo, Buffalo, NY 14203, USA
| | - Mark D Parker
- Department of Physiology and Biophysics, The State University of New York, The University at Buffalo, Buffalo, NY 14203, USA; Department of Ophthalmology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY, USA; State University of New York Eye Institute, University at Buffalo, The State University of New York, Buffalo, NY, USA
| | - Rossana Occhipinti
- Department of Physiology and Biophysics, Case Western Reserve University, School of Medicine, Cleveland, OH 44106, USA.
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36
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Voltage and pH difference across the membrane control the S4 voltage-sensor motion of the Hv1 proton channel. Sci Rep 2020; 10:21293. [PMID: 33277511 PMCID: PMC7718894 DOI: 10.1038/s41598-020-77986-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 10/28/2020] [Indexed: 12/26/2022] Open
Abstract
The voltage-gated proton channel Hv1 is expressed in a variety of cells, including macrophages, sperm, and lung epithelial cells. Hv1 is gated by both the membrane potential and the difference between the intra- and extracellular pH (ΔpH). The coupling of voltage- and ∆pH-sensing is such that Hv1 opens only when the electrochemical proton gradient is outwardly directed. However, the molecular mechanism of this coupling is not known. Here, we investigate the coupling between voltage- and ΔpH-sensing of Ciona intestinalis proton channel (ciHv1) using patch-clamp fluorometry (PCF) and proton uncaging. We show that changes in ΔpH can induce conformational changes of the S4 voltage sensor. Our results are consistent with the idea that S4 can detect both voltage and ΔpH.
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37
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Thermodynamics and Mechanism of the Membrane Permeation of Hv1 Channel Blockers. J Membr Biol 2020; 254:5-16. [PMID: 33196887 DOI: 10.1007/s00232-020-00149-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 10/14/2020] [Indexed: 02/08/2023]
Abstract
The voltage-gated proton channel Hv1 mediates efflux of protons from the cell. Hv1 integrally contributes to various physiological processes including pH homeostasis and the respiratory burst of phagocytes. Inhibition of Hv1 may provide therapeutic avenues for the treatment of inflammatory diseases, breast cancer, and ischemic brain damage. In this work, we investigate two prototypical Hv1 inhibitors, 2-guanidinobenzimidazole (2GBI), and 5-chloro-2-guanidinobenzimidazole (GBIC), from an experimentally screened class of guanidine derivatives. Both compounds block proton conduction by binding the same site located on the intracellular side of the channel. However, when added to the extracellular medium, the compounds strongly differ in their ability to inhibit proton conduction, suggesting substantial differences in membrane permeability. Here, we compute the potential of mean force for each compound to permeate through the membrane using atomistic molecular dynamics simulations with the adaptive biasing force method. Our results rationalize the putative distinction between these two blockers with respect to their abilities to permeate the cellular membrane.
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38
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Riazanski V, Sui Z, Nelson DJ. Kinetic Separation of Oxidative and Non-oxidative Metabolism in Single Phagosomes from Alveolar Macrophages: Impact on Bacterial Killing. iScience 2020; 23:101759. [PMID: 33251491 PMCID: PMC7677711 DOI: 10.1016/j.isci.2020.101759] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 09/07/2020] [Accepted: 10/29/2020] [Indexed: 01/10/2023] Open
Abstract
The relative contribution of the two phagosomal catabolic processes, oxidative and metabolic, was assessed in the killing of Pseudomonas aeruginosa in phagosomes of alveolar macrophages (AMs) from wild-type (p47-phox+/+) or NOX-defective (p47-phox−/−) mice. Free radical release and degradative acidification within AM phagosomes is sequential and separable. The initial NOX activity, identifiable as a transient alkalinization, leads to fast bacterial wall permeabilization by ROS. This is followed by V-ATPase-induced acidification and enzymatic bacterial degradation contributed through phagosomal-lysosomal fusion. The alkalinization/acidification ratio was variable among phagosomes within single cells of a given genotype and not as a function of macrophage M1 or M2 classification, possibly owing to uneven distribution of phagosomal transporter proteins. Irregular, excessive NOX activity prevents phago-lysosomal fusion, and the lack of V-ATPase-induced acidification leads to bacterial stasis in the phagosome. Thus, efficient phagosomal bacterial killing is a result of tightly balanced activity between two processes. Phagosomal NOX and V-ATPase activation is sequential and separable in macrophages Superoxide (O2-) inhibits lysosomal fusion thereby inhibiting phagosomal acidification Phagosomes in single cells are heterogeneous in NOX activity and thereby acidification NOX activity is the dominant factor in bactericidal efficacy in macrophage phagosomes
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Affiliation(s)
- Vladimir Riazanski
- The University of Chicago, Department of Pharmacological and Physiological Sciences, 947 E. 58th Street, MC 0926, Chicago, IL 60637, USA
- Corresponding author
| | - Zihao Sui
- The University of Chicago, Department of Pharmacological and Physiological Sciences, 947 E. 58th Street, MC 0926, Chicago, IL 60637, USA
| | - Deborah J. Nelson
- The University of Chicago, Department of Pharmacological and Physiological Sciences, 947 E. 58th Street, MC 0926, Chicago, IL 60637, USA
- Corresponding author
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39
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Smith RY, Morgan D, Sharma L, Cherny VV, Tidswell N, Molo MW, DeCoursey TE. Voltage-gated proton channels exist in the plasma membrane of human oocytes. Hum Reprod 2020; 34:1974-1983. [PMID: 31633762 DOI: 10.1093/humrep/dez178] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 07/10/2019] [Indexed: 12/25/2022] Open
Abstract
STUDY QUESTION Do human oocytes express voltage-gated proton channels? SUMMARY ANSWER Human oocytes exhibit voltage-gated proton currents. WHAT IS KNOWN ALREADY Voltage-gated proton currents have been reported in human sperm, where they contribute to capacitation and motility. No such studies of human oocytes exist. STUDY DESIGN, SIZE, DURATION Voltage-clamp studies were undertaken using entire oocytes and vesicles derived from oocytes and in excised patches of membrane from oocytes. PARTICIPANTS/MATERIALS, SETTING, METHODS Frozen, thawed human metaphase II oocytes were obtained from material donated to the gamete repository at the Rush Center for Advanced Reproductive Care. Prior to patch clamping, oocytes were warmed and equilibrated. Formation of an electrically tight seal requires exposing bare oolemma. Sections of the zona pellucida (ZP) were removed using a laser, followed by repeated pipetting, to further separate the oocyte from the ZP. Patch-clamp studies were performed using the whole-cell configuration on oocytes or vesicles derived from oocytes, and using inside-out patches of membrane, under conditions optimized to detect voltage-gated proton currents. MAIN RESULTS AND THE ROLE OF CHANCE Proton currents are present at significant levels in human oocytes where they exhibit properties similar to those reported in other human cells, as well as those in heterologous expression systems transfected with the HVCN1 gene that codes for the voltage-gated proton channel. LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION Human oocytes are large cells, which limits our ability to control the intracellular solution. Subtle effects of cryopreservation by vitrification and subsequent warming on properties of HVCN1, the HVCN1 gene product, cannot be ruled out. WIDER IMPLICATIONS OF THE FINDINGS Possible functions for voltage-gated proton channels in human oocytes may now be contemplated. STUDY FUNDING/COMPETING INTEREST(S) NIH R35GM126902 (TED), Bears Care (DM). No competing interests. TRIAL REGISTRATION NUMBER N/A.
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Affiliation(s)
- R Ya Smith
- Rush Center for Advanced Reproductive Care, Department of Obstetrics and Gynecology, Rush University Medical Center, Chicago, IL 60612, USA
| | - D Morgan
- Department of Physiology & Biophysics, Rush University, Chicago, IL 60612, USA
| | - L Sharma
- Rush Center for Advanced Reproductive Care, Department of Obstetrics and Gynecology, Rush University Medical Center, Chicago, IL 60612, USA
| | - V V Cherny
- Department of Physiology & Biophysics, Rush University, Chicago, IL 60612, USA
| | - N Tidswell
- Rush Center for Advanced Reproductive Care, Department of Obstetrics and Gynecology, Rush University Medical Center, Chicago, IL 60612, USA
| | - M W Molo
- Rush Center for Advanced Reproductive Care, Department of Obstetrics and Gynecology, Rush University Medical Center, Chicago, IL 60612, USA
| | - T E DeCoursey
- Department of Physiology & Biophysics, Rush University, Chicago, IL 60612, USA
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40
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Reithofer M, Karacs J, Strobl J, Kitzmüller C, Polak D, Seif K, Kamalov M, Becker CFW, Greiner G, Schmetterer K, Stary G, Bohle B, Jahn-Schmid B. Alum triggers infiltration of human neutrophils ex vivo and causes lysosomal destabilization and mitochondrial membrane potential-dependent NET-formation. FASEB J 2020; 34:14024-14041. [PMID: 32860638 PMCID: PMC7589265 DOI: 10.1096/fj.202001413r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 08/12/2020] [Accepted: 08/17/2020] [Indexed: 01/30/2023]
Abstract
Aluminium salts have been used in vaccines for decades. However, the mechanisms underlying their adjuvant effect are still unclear. Neutrophils, the first immune cells at the injection site, can release cellular DNA together with granular material, so‐called neutrophil extracellular traps (NETs). In mice, NETs apparently play a role in aluminium hydroxide (alum)‐adjuvant immune response to vaccines. Although no experimental data exist, this effect is assumed to be operative also in humans. As a first step to verify this knowledge in humans, we demonstrate that the injection of alum particles into human skin biopsies ex vivo leads to similar tissue infiltration of neutrophils and NET‐formation. Moreover, we characterized the mechanism leading to alum‐induced NET‐release in human neutrophils as rapid, NADPH oxidase‐independent process involving charge, phagocytosis, phagolysosomal rupture, Ca2+‐flux, hyperpolarization of the mitochondrial membrane, and mitochondrial ROS. Extracellular flow and inhibition experiments suggested that no additional energy from oxidative phosphorylation or glycolysis is required for NET‐release. This study suggests a so far unappreciated role for neutrophils in the initial phase of immune responses to alum‐containing vaccines in humans and provides novel insights into bioenergetic requirements of NET‐formation.
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Affiliation(s)
- Manuel Reithofer
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Jasmine Karacs
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Johanna Strobl
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - Claudia Kitzmüller
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Dominika Polak
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Katharina Seif
- Department of Surgery, Medical University of Vienna, Vienna, Austria
| | - Meder Kamalov
- Institute of Biological Chemistry, Department of Chemistry, University of Vienna, Vienna, Austria
| | - Christian F W Becker
- Institute of Biological Chemistry, Department of Chemistry, University of Vienna, Vienna, Austria
| | - Georg Greiner
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Klaus Schmetterer
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Georg Stary
- Department of Dermatology, Medical University of Vienna, Vienna, Austria.,Ludwig Boltzmann Institute for Rare and Undiagnosed Diseases, Vienna, Austria.,CeMM Research Center for Molecular Medicine, Vienna, Austria
| | - Barbara Bohle
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - Beatrice Jahn-Schmid
- Institute of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
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41
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Li X, Zhang H, Hou J, Ou R, Zhu Y, Zhao C, Qian T, Easton CD, Selomulya C, Hill MR, Wang H. Sulfonated Sub-1-nm Metal–Organic Framework Channels with Ultrahigh Proton Selectivity. J Am Chem Soc 2020; 142:9827-9833. [DOI: 10.1021/jacs.0c03554] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Xingya Li
- Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Huacheng Zhang
- Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Jue Hou
- Manufacturing, CSIRO, Clayton, 3168, Australia
| | - Ranwen Ou
- Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Yinlong Zhu
- Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Chen Zhao
- Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
| | - Tianyue Qian
- Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
| | | | | | - Matthew R. Hill
- Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
- Manufacturing, CSIRO, Clayton, 3168, Australia
| | - Huanting Wang
- Department of Chemical Engineering, Monash University, Clayton, Victoria 3800, Australia
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Bare DJ, Cherny VV, DeCoursey TE, Abukhdeir AM, Morgan D. Expression and function of voltage gated proton channels (Hv1) in MDA-MB-231 cells. PLoS One 2020; 15:e0227522. [PMID: 32374759 PMCID: PMC7202653 DOI: 10.1371/journal.pone.0227522] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 04/09/2020] [Indexed: 02/07/2023] Open
Abstract
Expression of the voltage gated proton channel (Hv1) as identified by immunocytochemistry has been reported previously in breast cancer tissue. Increased expression of HV1 was correlated with poor prognosis and decreased overall and disease-free survival but the mechanism of its involvement in the disease is unknown. Here we present electrophysiological recordings of HV1 channel activity, confirming its presence and function in the plasma membrane of a breast cancer cell line, MDA-MB-231. With western blotting we identify significant levels of HV1 expression in 3 out of 8 “triple negative” breast cancer cell lines (estrogen, progesterone, and HER2 receptor expression negative). We examine the function of HV1 in breast cancer using MDA-MB-231 cells as a model by suppressing the expression of HV1 using shRNA (knock-down; KD) and by eliminating HV1 using CRISPR/Cas9 gene editing (knock-out; KO). Surprisingly, these two approaches produced incongruous effects. Knock-down of HV1 using shRNA resulted in slower cell migration in a scratch assay and a significant reduction in H2O2 release. In contrast, HV1 Knock-out cells did not show reduced migration or H2O2 release. HV1 KO but not KD cells showed an increased glycolytic rate accompanied by an increase in p-AKT (phospho-AKT, Ser473) activity. The expression of CD171/LCAM-1, an adhesion molecule and prognostic indicator for breast cancer, was reduced in HV1 KO cells. When we compared MDA-MB-231 xenograft growth rates in immunocompromised mice, tumors from HV1 KO cells grew less than WT in mass, with lower staining for the Ki-67 marker for cell proliferation rate. Therefore, deletion of HV1 expression in MDA-MB-231 cells limits tumor growth rate. The limited growth thus appears to be independent of oxidant production by NADPH oxidase molecules and to be mediated by cell adhesion molecules. Although HV1 KO and KD affect certain cellular mechanisms differently, both implicate HV1-mediated pathways for control of tumor growth in the MDA-MB-231 cell line.
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Affiliation(s)
- Dan J Bare
- Department of Physiology & Biophysics, Rush University, Chicago, IL, United States of America
| | - Vladimir V Cherny
- Department of Physiology & Biophysics, Rush University, Chicago, IL, United States of America
| | - Thomas E DeCoursey
- Department of Physiology & Biophysics, Rush University, Chicago, IL, United States of America
| | - Abde M Abukhdeir
- Department of Internal Medicine, Rush University Medical Center, Chicago, IL, United States of America
| | - Deri Morgan
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, MO, United States of America
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43
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Chaves G, Bungert-Plümke S, Franzen A, Mahorivska I, Musset B. Zinc modulation of proton currents in a new voltage-gated proton channel suggests a mechanism of inhibition. FEBS J 2020; 287:4996-5018. [PMID: 32160407 PMCID: PMC7754295 DOI: 10.1111/febs.15291] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 01/10/2020] [Accepted: 03/10/2020] [Indexed: 02/03/2023]
Abstract
The HV1 voltage‐gated proton (HV1) channel is a key component of the cellular proton extrusion machinery and is pivotal for charge compensation during the respiratory burst of phagocytes. The best‐described physiological inhibitor of HV1 is Zn2+. Externally applied ZnCl2 drastically reduces proton currents reportedly recorded in Homo sapiens, Rattus norvegicus, Mus musculus, Oryctolagus cuniculus, Rana esculenta, Helix aspersa, Ciona intestinalis, Coccolithus pelagicus, Emiliania huxleyi, Danio rerio, Helisoma trivolvis, and Lingulodinium polyedrum, but with considerable species variability. Here, we report the effects of Zn2+ and Cd2+ on HV1 from Nicoletia phytophila, NpHV1. We introduced mutations at potential Zn2+ coordination sites and measured Zn2+ inhibition in different extracellular pH, with Zn2+ concentrations up to 1000 μm. Zn2+ inhibition in NpHV1 was quantified by the slowing of the activation time constant and a positive shift of the conductance–voltage curve. Replacing aspartate in the S3‐S4 loop with histidine (D145H) enhanced both the slowing of activation kinetics and the shift in the voltage–conductance curve, such that Zn2+ inhibition closely resembled that of the human channel. Histidine is much more effective than aspartate in coordinating Zn2+ in the S3‐S4 linker. A simple Hodgkin Huxley model of NpHV1 suggests a decrease in the opening rate if it is inhibited by zinc or cadmium. Limiting slope measurements and high‐resolution clear native gel electrophoresis (hrCNE) confirmed that NpHV1 functions as a dimer. The data support the hypothesis that zinc is coordinated in between the dimer instead of the monomer. Zinc coordination sites may be potential targets for drug development.
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Affiliation(s)
- Gustavo Chaves
- Institut für Physiologie und Pathophysiologie, Paracelsus Universität Salzburg Standort Nürnberg, Nuremberg, Germany
| | - Stefanie Bungert-Plümke
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4) Forschungszentrum Jülich, Jülich, Germany
| | - Arne Franzen
- Institute of Complex Systems, Zelluläre Biophysik (ICS-4) Forschungszentrum Jülich, Jülich, Germany
| | - Iryna Mahorivska
- Institut für Physiologie und Pathophysiologie, Paracelsus Universität Salzburg Standort Nürnberg, Nuremberg, Germany
| | - Boris Musset
- Institut für Physiologie und Pathophysiologie, Paracelsus Universität Salzburg Standort Nürnberg, Nuremberg, Germany
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44
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Tang D, Yang Y, Xiao Z, Xu J, Yang Q, Dai H, Liang S, Tang C, Dong H, Liu Z. Scorpion toxin inhibits the voltage-gated proton channel using a Zn 2+ -like long-range conformational coupling mechanism. Br J Pharmacol 2020; 177:2351-2364. [PMID: 31975366 DOI: 10.1111/bph.14984] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 12/27/2019] [Accepted: 12/30/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AND PURPOSE Blocking the voltage-gated proton channel HV 1 is a promising strategy for the treatment of diseases like ischaemia stroke and cancer. However, few HV 1 channel antagonists have been reported. Here, we have identified a novel HV 1 channel antagonist from scorpion venom and have elucidated its action mechanism. EXPERIMENTAL APPROACH HV 1 and NaV channels were heterologously expressed in mammalian cell lines and their currents recorded using whole-cell patch clamp. Site-directed mutagenesis was used to generate mutants. Toxins were recombinantly produced in Escherichia coli. AGAP/W38F-HV 1 interaction was modelled by molecular dynamics simulations. KEY RESULTS The scorpion toxin AGAP (anti-tumour analgesic peptide) potently inhibited HV 1 currents. One AGAP mutant has reduced NaV channel activity but intact HV 1 activity (AGAP/W38F). AGAP/W38F inhibited HV 1 channel activation by trapping its S4 voltage sensor in a deactivated state and inhibited HV 1 currents with less pH dependence than Zn2+ . Mutation analysis showed that the binding pockets of AGAP/W38F and Zn2+ in HV 1 channel partly overlapped (common sites are His140 and His193). The E153A mutation at the intracellular Coulombic network (ICN) in HV 1 channel markedly reduced AGAP/W38F inhibition, as observed for Zn2+ . Experimental data and MD simulations suggested that AGAP/W38F inhibited HV 1 channel using a Zn2+ -like long-range conformational coupling mechanism. CONCLUSION AND IMPLICATIONS Our results suggest that the Zn2+ binding pocket in HV 1 channel might be a hotspot for modulators and valuable for designing HV 1 channel ligands. Moreover, AGAP/W38F is a useful molecular probe to study HV 1 channel and a lead compound for drug development.
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Affiliation(s)
- Dongfang Tang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Yuqin Yang
- Kuang Yaming Honors School, Nanjing University, Nanjing, China.,Institute for Brain Sciences, Nanjing University, Nanjing, China
| | - Zhen Xiao
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Jiahui Xu
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Qiuchu Yang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Han Dai
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Songping Liang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Cheng Tang
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
| | - Hao Dong
- Kuang Yaming Honors School, Nanjing University, Nanjing, China.,Institute for Brain Sciences, Nanjing University, Nanjing, China
| | - Zhonghua Liu
- The National and Local Joint Engineering Laboratory of Animal Peptide Drug Development, College of Life Sciences, Hunan Normal University, Changsha, China
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45
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Pang H, Li J, Du H, Gao Y, Lv J, Liu Y, Li SJ. Loss of voltage-gated proton channel Hv1 leads to diet-induced obesity in mice. BMJ Open Diabetes Res Care 2020; 8:8/1/e000951. [PMID: 32049639 PMCID: PMC7039614 DOI: 10.1136/bmjdrc-2019-000951] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Revised: 12/05/2019] [Accepted: 12/13/2019] [Indexed: 01/02/2023] Open
Abstract
OBJECTIVE The voltage-gated proton channel Hv1 has been proposed to mediate NADPH oxidase (NOX) function by regulating intracellular pH during respiratory bursts. In our previous work, we showed that Hv1 is expressed in pancreatic β cells and positively regulates insulin secretion. Here, we investigated the role of Hv1 in adipose tissue differentiation, metabolic homeostasis and insulin sensitivity using Hv1 knockout (KO) mice. DESIGN Mice with genetic deletion of Hv1 are treated with high-fat diet (HFD) similar to wild-type (WT) mice. Body weight gain, adiposity, insulin sensitivity and gene expressions in both adipose tissue and liver were analyzed. RESULTS Mice with genetic deletion of Hv1 display overt obesity with higher body weight gain and accumulation of adipose tissue compared with similarly HFD-treated WT. Hv1-deficient mice develop more glucose intolerance than WT, but no significant difference in insulin resistance, after fed with HFD. Deficiency of Hv1 results in a remarkable increase in epididymal adipocyte weight and size, while the gene expressions of proinflammatory factors and cytokines are obviously enhanced in the HFD-fed mice. Furthermore, the gene expression of Hv1 is increased in the HFD-fed mice, which is accompanied by the increase of NOX2 and NOX4. In addition, there is more severely diet-induced steatosis and inflammation in liver in KO mice. CONCLUSION Our data demonstrated that lacking of Hv1 results in diet-induced obesity in mice through inflammation and hepatic steatosis. This study suggested that Hv1 acts as a positive regulator of metabolic homeostasis and a potential target for antiobesity drugs in therapy and may serve as an adaptive mechanism in cooperating with NOX to mediate reactive oxygen species for adipogenesis and insulin sensitivity.
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Affiliation(s)
- Huimin Pang
- Department of Biophysics, School of Physics Science,The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071, P. R. China
| | - Jinwen Li
- Department of Biophysics, School of Physics Science,The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071, P. R. China
| | - Hongyan Du
- Department of Biophysics, School of Physics Science,The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071, P. R. 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
| | - Jili Lv
- Department of Biophysics, School of Physics Science,The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071, P. R. China
| | - Yanxia Liu
- Department of Biophysics, School of Physics Science,The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071, P. R. China
| | - Shu Jie Li
- Department of Biophysics, School of Physics Science,The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071, P. R. China
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46
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Hydrophobic gasket mutation produces gating pore currents in closed human voltage-gated proton channels. Proc Natl Acad Sci U S A 2019; 116:18951-18961. [PMID: 31462498 PMCID: PMC6754559 DOI: 10.1073/pnas.1905462116] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
A large family of membrane proteins, voltage-gated ion channels, regulate a vast array of physiological functions in essentially all life forms. How these molecules sense membrane potential and respond by creating ionic conduction is incompletely understood. The voltage sensors of these channels contain a “hydrophobic gasket,” a ring of hydrophobic amino acids near the center of the membrane, separating internal and external aqueous solutions. Although voltage-gated proton channels, HV1, resemble voltage-sensing domains of other channels, they differ fundamentally. On depolarization, HV1 conducts protons, whereas other voltage sensors open a physically distinct pore. We identify Val109, Phe150, Val177, and Val178 as the hHV1 hydrophobic gasket. Replacement with less hydrophobic amino acids accelerated channel opening and caused proton-selective leak through closed channels. The hydrophobic gasket (HG), a ring of hydrophobic amino acids in the voltage-sensing domain of most voltage-gated ion channels, forms a constriction between internal and external aqueous vestibules. Cationic Arg or Lys side chains lining the S4 helix move through this “gating pore” when the channel opens. S4 movement may occur during gating of the human voltage-gated proton channel, hHV1, but proton current flows through the same pore in open channels. Here, we replaced putative HG residues with less hydrophobic residues or acidic Asp. Substitution of individuals, pairs, or all 3 HG positions did not impair proton selectivity. Evidently, the HG does not act as a secondary selectivity filter. However, 2 unexpected functions of the HG in HV1 were discovered. Mutating HG residues independently accelerated channel opening and compromised the closed state. Mutants exhibited open–closed gating, but strikingly, at negative voltages where “normal” gating produces a nonconducting closed state, the channel leaked protons. Closed-channel proton current was smaller than open-channel current and was inhibited by 10 μM Zn2+. Extreme hyperpolarization produced a deeper closed state through a weakly voltage-dependent transition. We functionally identify the HG as Val109, Phe150, Val177, and Val178, which play a critical and exclusive role in preventing H+ influx through closed channels. Molecular dynamics simulations revealed enhanced mobility of Arg208 in mutants exhibiting H+ leak. Mutation of HG residues produces gating pore currents reminiscent of several channelopathies.
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47
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Hahn J, Euler M, Kilgus E, Kienhöfer D, Stoof J, Knopf J, Hahn M, Harrer T, Hultqvist M, Olofsson P, Mokhir A, Holmdahl R, Herrmann M, Schett G, Muñoz LE, Hoffmann MH. NOX2 mediates quiescent handling of dead cell remnants in phagocytes. Redox Biol 2019; 26:101279. [PMID: 31349119 PMCID: PMC6669319 DOI: 10.1016/j.redox.2019.101279] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 07/09/2019] [Accepted: 07/19/2019] [Indexed: 12/13/2022] Open
Abstract
The phagocyte NADPH oxidase (the NOX2 complex) generates superoxide, the precursor to reactive oxygen species (ROS). ROS possess both antimicrobial and immunoregulatory function. Inactivating mutations in alleles of the NOX2 complex cause chronic granulomatous disease (CGD), characterized by an enhanced susceptibility to infections and autoimmune diseases such as Systemic lupus erythematosus (SLE). The latter is characterized by insufficient removal of dead cells, resulting in an autoimmune response against components of the cell's nucleus when non-cleared apoptotic cells lose their membrane integrity and present autoantigenic molecules in an inflammatory context. Here we aimed to shed light on the role of the NOX2 complex in handling of secondary necrotic cells (SNECs) and associated consequences for inflammation and autoimmunity during lupus. We show that individuals with SLE and CGD display accumulation of SNECs in blood monocytes and neutrophils. In a CGD phenotypic mouse strain (Ncf1** mice) build-up of SNECs in Ly6CHI blood monocytes was connected with a delayed degradation of the phagosomal cargo and accompanied by production of inflammatory mediators. Treatment with H2O2 or activators of ROS-formation reconstituted phagosomal abundance of SNECs to normal levels. Induction of experimental lupus further induced increased antibody-dependent uptake of SNECs into neutrophils. Lupus-primed Ncf1** neutrophils took up more SNECs than wild type neutrophils, whereas SNEC-accumulation in regulatory Ly6C−/LO monocytes was lower in Ncf1**mice. We deduce that the inflammatory rerouting of immune-stimulatory necrotic material into inflammatory phagocyte subsets contributes to the connection between low ROS production by the NOX2 complex and SLE.
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Affiliation(s)
- Jonas Hahn
- Department of Medicine 3, Rheumatology and Immunology, Friedrich Alexander-University Erlangen-Nürnberg, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Maximilien Euler
- Department of Medicine 3, Rheumatology and Immunology, Friedrich Alexander-University Erlangen-Nürnberg, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Emelie Kilgus
- Department of Medicine 3, Rheumatology and Immunology, Friedrich Alexander-University Erlangen-Nürnberg, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Deborah Kienhöfer
- Department of Medicine 3, Rheumatology and Immunology, Friedrich Alexander-University Erlangen-Nürnberg, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Julia Stoof
- Department of Medicine 3, Rheumatology and Immunology, Friedrich Alexander-University Erlangen-Nürnberg, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Jasmin Knopf
- Department of Medicine 3, Rheumatology and Immunology, Friedrich Alexander-University Erlangen-Nürnberg, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Madelaine Hahn
- Department of Medicine 3, Rheumatology and Immunology, Friedrich Alexander-University Erlangen-Nürnberg, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Thomas Harrer
- Department of Medicine 3, Rheumatology and Immunology, Friedrich Alexander-University Erlangen-Nürnberg, Universitätsklinikum Erlangen, Erlangen, Germany
| | | | - Peter Olofsson
- Redoxis/Pronoxis AB, Medicon Village Lund, Sweden; Section of Medical Inflammation Research, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Andriy Mokhir
- Department of Chemistry and Pharmacy, Organic Chemistry II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Rikard Holmdahl
- Section of Medical Inflammation Research, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Martin Herrmann
- Department of Medicine 3, Rheumatology and Immunology, Friedrich Alexander-University Erlangen-Nürnberg, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Georg Schett
- Department of Medicine 3, Rheumatology and Immunology, Friedrich Alexander-University Erlangen-Nürnberg, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Luis E Muñoz
- Department of Medicine 3, Rheumatology and Immunology, Friedrich Alexander-University Erlangen-Nürnberg, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Markus H Hoffmann
- Department of Medicine 3, Rheumatology and Immunology, Friedrich Alexander-University Erlangen-Nürnberg, Universitätsklinikum Erlangen, Erlangen, Germany.
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48
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Chen Q, Zeng W, She J, Bai XC, Jiang Y. Structural and functional characterization of an otopetrin family proton channel. eLife 2019; 8:46710. [PMID: 30973323 PMCID: PMC6483595 DOI: 10.7554/elife.46710] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Accepted: 04/11/2019] [Indexed: 12/14/2022] Open
Abstract
The otopetrin (OTOP) proteins were recently characterized as proton channels. Here we present the cryo-EM structure of OTOP3 from Xenopus tropicalis (XtOTOP3) along with functional characterization of the channel. XtOTOP3 forms a homodimer with each subunit containing 12 transmembrane helices that can be divided into two structurally homologous halves; each half assembles as an α-helical barrel that could potentially serve as a proton conduction pore. Both pores open from the extracellular half before becoming occluded at a central constriction point consisting of three highly conserved residues - Gln232/585-Asp262/Asn623-Tyr322/666 (the constriction triads). Mutagenesis shows that the constriction triad from the second pore is less amenable to perturbation than that of the first pore, suggesting an unequal contribution between the two pores to proton transport. We also identified several key residues at the interface between the two pores that are functionally important, particularly Asp509, which confers intracellular pH-dependent desensitization to OTOP channels.
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Affiliation(s)
- Qingfeng Chen
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Weizhong Zeng
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
| | - Ji She
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States
| | - Xiao-Chen Bai
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, United States
| | - Youxing Jiang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, United States.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, United States.,Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States
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49
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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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50
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Differential antibacterial control by neutrophil subsets. Blood Adv 2019; 2:1344-1355. [PMID: 29895625 DOI: 10.1182/bloodadvances.2017015578] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 05/06/2018] [Indexed: 12/21/2022] Open
Abstract
Neutrophils comprise a heterogeneous population of cells essential for bacterial eradication, and defects in neutrophil function are associated with increased susceptibility to infection. In this study, neutrophils from healthy controls were shown to prevent bacterial proliferation for at least 48 hours when cocultured with methicillin-resistant Staphylococcus aureus (MRSA) in tissue-like scaffolds by establishing a bacteriostatic environment inside their phagolysosome. This intracellular bacterial containment is independent of reactive oxygen species because neutrophils that lack a functional nicotinamide adenine dinucleotide phosphate-oxidase complex displayed no defect in intracellular bacterial containment, whereas killing of the pathogen was impaired. During acute inflammation, a subset of CD16bright/CD62Ldim hypersegmented neutrophils displayed normal phagocytosis associated with a remarkably poor capacity to contain bacteria intracellularly. Conversely, CD16dim-banded neutrophils were the only neutrophil subset that adequately contained MRSA. These findings demonstrate a clear neutrophil heterogeneity in their antimicrobial capacity and the appearance of neutrophil subsets with a clear differentiation in functionality during acute inflammation. Furthermore, this study provides an evolutionary basis for the rapid release of banded neutrophils into the circulation during acute inflammation.
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