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Chida K, Kanazawa H, Kinoshita H, Roy AM, Hakamada K, Takabe K. The role of lidocaine in cancer progression and patient survival. Pharmacol Ther 2024; 259:108654. [PMID: 38701900 PMCID: PMC11162934 DOI: 10.1016/j.pharmthera.2024.108654] [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: 01/08/2024] [Revised: 04/17/2024] [Accepted: 04/30/2024] [Indexed: 05/05/2024]
Abstract
Since its development in 1943, lidocaine has been one of the most commonly used local anesthesia agents for surgical procedures. Lidocaine alters neuronal signal transmission by prolonging the inactivation of fast voltage-gated sodium channels in the cell membrane of neurons, which are responsible for action potential propagation. Recently, it has attracted attention due to emerging evidence suggesting its potential antitumor properties, particularly in the in vitro setting. Further, local administration of lidocaine around the tumor immediately prior to surgical removal has been shown to improve overall survival in breast cancer patients. However, the exact mechanisms driving these antitumor effects remain largely unclear. In this article, we will review the existing literature on the mechanism of lidocaine as a local anesthetic, its effects on the cancer cells and the tumor microenvironment, involved pathways, and cancer progression. Additionally, we will explore recent reports highlighting its impact on clinical outcomes in cancer patients. Taken together, there remains significant ambiguity surrounding lidocaine's functions and roles in cancer biology, particularly in perioperative setting.
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Affiliation(s)
- Kohei Chida
- Department of Surgical Oncology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; Department of Gastroenterological Surgery, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan.
| | - Hirofumi Kanazawa
- The University of Texas Health Science Center at Tyler School of Medicine, TX, USA.
| | - Hirotaka Kinoshita
- Department of Anesthesiology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki 036-8562, Japan.
| | - Arya Mariam Roy
- Department of Hematology and Oncology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA.
| | - Kenichi Hakamada
- Department of Gastroenterological Surgery, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan.
| | - Kazuaki Takabe
- Department of Surgical Oncology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA; Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa 236-0004, Japan; Department of Surgery, University at Buffalo Jacobs School of Medicine and Biomedical Sciences, The State University of New York, Buffalo, NY 14263, USA; Department of Breast Surgery and Oncology, Tokyo Medical University, Tokyo 160-8402, Japan; Division of Digestive and General Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata 951-8510, Japan; Department of Breast Surgery, Fukushima Medical University School of Medicine, Fukushima 960-1295, Japan; Department of Breast Surgery, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, USA.
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2
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Holderby KG, Kozak JA. Use of tetraethylammonium (TEA) and Tris loading for blocking TRPM7 channels in intact cells. Front Pharmacol 2024; 15:1341799. [PMID: 38659572 PMCID: PMC11039802 DOI: 10.3389/fphar.2024.1341799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 03/26/2024] [Indexed: 04/26/2024] Open
Abstract
Tetraethylammonium (TEA), a quaternary ammonium compound, is a well-known blocker of potassium channels belonging to various subfamilies, such as KV1-3, KCa1, 2 and prokaryotic KcsA. In many cases, TEA acts from the extracellular side by open pore blockade. TEA can also block transient receptor potential (TRP) cation channels, such as TRPM7, in a voltage-dependent manner. In human T lymphocytes, intracellular (cytosolic) TEA and its analog TMA (tetramethylammonium) inhibit TRPM7 channel currents in the outward but not inward direction. By contrast, intracellular Mg2+, protons and polyamines inhibit both outward and inward current components equally. Likewise, the majority of available pharmacological tools inhibit TRPM7 channels in a voltage-independent manner. Since TRPM7 is a steeply outwardly rectifying conductance, voltage-dependent blockers can be useful for studying the cellular functions of this channel. TRPM7 protein is endogenously expressed in diverse cell lines, including HEK, HeLa, CHO, RBL and Jurkat. Using patch-clamp electrophysiology, we found that incubating HEK293 and Jurkat T cells overnight in the presence of 20 mM TEA-Cl, resulted in the nearly complete blockade of whole-cell TRPM7 outward current, measured at break-in. By contrast, the inward current was unchanged in TEA-loaded cells. The blockade was fully reversible after washout of intracellular solution in whole-cell but not in perforated-patch recording configurations. Overnight incubation with 20 mM TMA-Cl resulted in a more modest blockade of the outward TRPM7 current. Internal 129 mM TMA and TEA eliminated most of the outward current. TEA uptake in transfected HEK293 cells led to blockade of recombinant murine TRPM7 and the Mg2+ and pH insensitive Ser1107Arg variant. Unexpectedly, Tris-HCl, a widely used pH buffer, could similarly be loaded into Jurkat and HEK cells, and preferentially blocked outward TRPM7 currents. 20 mM and 129 mM Tris in the internal solution blocked TRPM7 current in outward but not inward direction. Voltage-dependent channel blockade by TEA, TMA and Tris loading will be useful for studying the properties and functions of TRPM7-mediated ion transport in intact cells.
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Affiliation(s)
- Katherine G. Holderby
- Undergraduate Program in Physiology and Neuroscience, Dayton, OH, United States
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, United States
| | - J. Ashot Kozak
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, United States
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3
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Chubanov V, Köttgen M, Touyz RM, Gudermann T. TRPM channels in health and disease. Nat Rev Nephrol 2024; 20:175-187. [PMID: 37853091 DOI: 10.1038/s41581-023-00777-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/25/2023] [Indexed: 10/20/2023]
Abstract
Different cell channels and transporters tightly regulate cytoplasmic levels and the intraorganelle distribution of cations. Perturbations in these processes lead to human diseases that are frequently associated with kidney impairment. The family of melastatin-related transient receptor potential (TRPM) channels, which has eight members in mammals (TRPM1-TRPM8), includes ion channels that are highly permeable to divalent cations, such as Ca2+, Mg2+ and Zn2+ (TRPM1, TRPM3, TRPM6 and TRPM7), non-selective cation channels (TRPM2 and TRPM8) and monovalent cation-selective channels (TRPM4 and TRPM5). Three family members contain an enzymatic protein moiety: TRPM6 and TRPM7 are fused to α-kinase domains, whereas TRPM2 is linked to an ADP-ribose-binding NUDT9 homology domain. TRPM channels also function as crucial cellular sensors involved in many physiological processes, including mineral homeostasis, blood pressure, cardiac rhythm and immunity, as well as photoreception, taste reception and thermoreception. TRPM channels are abundantly expressed in the kidney. Mutations in TRPM genes cause several inherited human diseases, and preclinical studies in animal models of human disease have highlighted TRPM channels as promising new therapeutic targets. Here, we provide an overview of this rapidly evolving research area and delineate the emerging role of TRPM channels in kidney pathophysiology.
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Affiliation(s)
- Vladimir Chubanov
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.
| | - Michael Köttgen
- Renal Division, Department of Medicine, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS - Centre for Integrative Biological Signalling Studies, Freiburg, Germany
| | - Rhian M Touyz
- Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, Canada
| | - Thomas Gudermann
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.
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4
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Busey GW, Manjegowda MC, Huang T, Iobst WH, Naphade SS, Kennedy JA, Doyle CA, Seegren PV, Lynch KR, Desai BN. Analogs of FTY720 inhibit TRPM7 but not S1PRs and exert multimodal anti-inflammatory effects. J Gen Physiol 2024; 156:e202313419. [PMID: 37943249 PMCID: PMC10635799 DOI: 10.1085/jgp.202313419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 08/04/2023] [Accepted: 10/20/2023] [Indexed: 11/10/2023] Open
Abstract
TRPM7, a TRP channel with ion conductance and kinase activities, has emerged as an attractive drug target for immunomodulation. Reverse genetics and cell biological studies have already established a key role for TRPM7 in the inflammatory activation of macrophages. Advancing TRPM7 as a viable molecular target for immunomodulation requires selective TRPM7 inhibitors with in vivo tolerability and efficacy. Such inhibitors have the potential to interdict inflammatory cascades mediated by systemic and tissue-specialized macrophages. FTY720, an FDA-approved drug for multiple sclerosis inhibits TRPM7. However, FTY720 is a prodrug and its metabolite, FTY720-phosphate, is a potent agonist of sphingosine-1-phosphate (S1P) receptors. In this study, we test non-phosphorylatable FTY720 analogs, which are inert against S1PRs and well tolerated in vivo, for activity against TRPM7 and tissue bioavailability. Using patch clamp electrophysiology, we show that VPC01091.4 and AAL-149 block TRPM7 current at low micromolar concentrations. In culture, they act directly on macrophages to blunt LPS-induced inflammatory cytokine expression, though this likely occurrs through multiple molecular targets. We found that VPC01091.4 has significant and rapid accumulation in the brain and lungs, along with direct anti-inflammatory action on alveolar macrophages and microglia. Finally, using a mouse model of endotoxemia, we show VPC01091.4 to be an efficacious anti-inflammatory agent that arrests systemic inflammation in vivo. Together, these findings identify novel small molecule inhibitors that allow TRPM7 channel inhibition independent of S1P receptor targeting which demonstrate potent, polymodal anti-inflammatory activities ex vivo and in vivo.
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Affiliation(s)
- Gregory W. Busey
- Pharmacology Department, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Mohan C. Manjegowda
- Pharmacology Department, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Tao Huang
- Pharmacology Department, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Wesley H. Iobst
- Pharmacology Department, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Shardul S. Naphade
- Pharmacology Department, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Joel A. Kennedy
- Pharmacology Department, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Catherine A. Doyle
- Pharmacology Department, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Philip V. Seegren
- Pharmacology Department, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Kevin R. Lynch
- Pharmacology Department, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Bimal N. Desai
- Pharmacology Department, University of Virginia School of Medicine, Charlottesville, VA, USA
- Carter Immunology Center, University of Virginia School of Medicine, Charlottesville, VA, USA
- Cardiovascular Research Center, University of Virginia, Charlottesville, VA, USA
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5
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Okada Y, Numata T, Sabirov RZ, Kashio M, Merzlyak PG, Sato-Numata K. Cell death induction and protection by activation of ubiquitously expressed anion/cation channels. Part 3: the roles and properties of TRPM2 and TRPM7. Front Cell Dev Biol 2023; 11:1246955. [PMID: 37842082 PMCID: PMC10576435 DOI: 10.3389/fcell.2023.1246955] [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: 06/25/2023] [Accepted: 09/15/2023] [Indexed: 10/17/2023] Open
Abstract
Cell volume regulation (CVR) is a prerequisite for animal cells to survive and fulfill their functions. CVR dysfunction is essentially involved in the induction of cell death. In fact, sustained normotonic cell swelling and shrinkage are associated with necrosis and apoptosis, and thus called the necrotic volume increase (NVI) and the apoptotic volume decrease (AVD), respectively. Since a number of ubiquitously expressed ion channels are involved in the CVR processes, these volume-regulatory ion channels are also implicated in the NVI and AVD events. In Part 1 and Part 2 of this series of review articles, we described the roles of swelling-activated anion channels called VSOR or VRAC and acid-activated anion channels called ASOR or PAC in CVR and cell death processes. Here, Part 3 focuses on therein roles of Ca2+-permeable non-selective TRPM2 and TRPM7 cation channels activated by stress. First, we summarize their phenotypic properties and molecular structure. Second, we describe their roles in CVR. Since cell death induction is tightly coupled to dysfunction of CVR, third, we focus on their participation in the induction of or protection against cell death under oxidative, acidotoxic, excitotoxic, and ischemic conditions. In this regard, we pay attention to the sensitivity of TRPM2 and TRPM7 to a variety of stress as well as to their capability to physicall and functionally interact with other volume-related channels and membrane enzymes. Also, we summarize a large number of reports hitherto published in which TRPM2 and TRPM7 channels are shown to be involved in cell death associated with a variety of diseases or disorders, in some cases as double-edged swords. Lastly, we attempt to describe how TRPM2 and TRPM7 are organized in the ionic mechanisms leading to cell death induction and protection.
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Affiliation(s)
- Yasunobu Okada
- National Institute for Physiological Sciences (NIPS), Okazaki, Japan
- Department of Integrative Physiology, Graduate School of Medicine, AkitaUniversity, Akita, Japan
- Department of Physiology, School of Medicine, Aichi Medical Uniersity, Nagakute, Japan
- Department of Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan
- Cardiovascular Research Institute, Yokohama City University, Yokohama, Japan
| | - Tomohiro Numata
- Department of Integrative Physiology, Graduate School of Medicine, AkitaUniversity, Akita, Japan
| | - Ravshan Z. Sabirov
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent, Uzbekistan
| | - Makiko Kashio
- National Institute for Physiological Sciences (NIPS), Okazaki, Japan
- Department of Physiology, School of Medicine, Aichi Medical Uniersity, Nagakute, Japan
| | - Peter G. Merzlyak
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent, Uzbekistan
| | - Kaori Sato-Numata
- Department of Integrative Physiology, Graduate School of Medicine, AkitaUniversity, Akita, Japan
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6
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Busey GW, Manjegowda MC, Huang T, Iobst WH, Naphade SS, Kennedy JA, Doyle CA, Seegren PV, Lynch KR, Desai BN. Novel TRPM7 inhibitors with potent anti-inflammatory effects in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.22.541802. [PMID: 37662207 PMCID: PMC10473597 DOI: 10.1101/2023.05.22.541802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
TRPM7, a TRP channel with ion conductance and kinase activities, has emerged as an attractive drug target for immunomodulation. Reverse genetics and cell biological studies have already established a key role for TRPM7 in the inflammatory activation of macrophages. Advancing TRPM7 as a viable molecular target for immunomodulation requires selective TRPM7 inhibitors with in vivo tolerability and efficacy. Such inhibitors have the potential to interdict inflammatory cascades mediated by systemic and tissue-specialized macrophages. FTY720, an FDA-approved drug for multiple sclerosis inhibits TRPM7. However, FTY720 is a prodrug and its metabolite, FTY720-phosphate, is a potent agonist of sphingosine 1-phosphate (S1P) receptors. In this study, we tested non-phosphorylatable FTY720 analogs, which are inert against S1PRs and well tolerated in vivo , for activity against TRPM7 and tissue bioavailability. Using patch clamp electrophysiology, we show that VPC01091.4 and AAL-149 block TRPM7 current at low micromolar concentrations. In culture, they act directly on macrophages to blunt LPS-induced inflammatory cytokine expression, an effect that is predominantly but not solely mediated by TRPM7. We found that VPC01091.4 has significant and rapid accumulation in the brain and lungs, along with direct anti-inflammatory action on alveolar macrophages and microglia. Finally, using a mouse model of endotoxemia, we show VPC01091.4 to be an efficacious anti-inflammatory agent that arrests systemic inflammation in vivo . Together, these findings identify novel small molecule inhibitors that allow TRPM7 channel inhibition independent of S1P receptor targeting. These inhibitors exhibit potent anti-inflammatory properties that are mediated by TRPM7 and likely other molecular targets that remain to be identified.
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7
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Nadezhdin KD, Correia L, Narangoda C, Patel DS, Neuberger A, Gudermann T, Kurnikova MG, Chubanov V, Sobolevsky AI. Structural mechanisms of TRPM7 activation and inhibition. Nat Commun 2023; 14:2639. [PMID: 37156763 PMCID: PMC10167348 DOI: 10.1038/s41467-023-38362-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 04/27/2023] [Indexed: 05/10/2023] Open
Abstract
The transient receptor potential channel TRPM7 is a master regulator of the organismal balance of divalent cations that plays an essential role in embryonic development, immune responses, cell mobility, proliferation, and differentiation. TRPM7 is implicated in neuronal and cardiovascular disorders, tumor progression and has emerged as a new drug target. Here we use cryo-EM, functional analysis, and molecular dynamics simulations to uncover two distinct structural mechanisms of TRPM7 activation by a gain-of-function mutation and by the agonist naltriben, which show different conformational dynamics and domain involvement. We identify a binding site for highly potent and selective inhibitors and show that they act by stabilizing the TRPM7 closed state. The discovered structural mechanisms provide foundations for understanding the molecular basis of TRPM7 channelopathies and drug development.
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Affiliation(s)
- Kirill D Nadezhdin
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Leonor Correia
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Chamali Narangoda
- Chemistry Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Dhilon S Patel
- Chemistry Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Arthur Neuberger
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | - Thomas Gudermann
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
- Comprehensive Pneumology Center, German Center for Lung Research (DZL), Munich, Germany
| | - Maria G Kurnikova
- Chemistry Department, Carnegie Mellon University, Pittsburgh, PA, USA.
| | - Vladimir Chubanov
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.
| | - Alexander I Sobolevsky
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
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8
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Mack ML, Huang W, Chang SL. Involvement of TRPM7 in Alcohol-Induced Damage of the Blood-Brain Barrier in the Presence of HIV Viral Proteins. Int J Mol Sci 2023; 24:1910. [PMID: 36768230 PMCID: PMC9916124 DOI: 10.3390/ijms24031910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 12/22/2022] [Accepted: 01/14/2023] [Indexed: 01/21/2023] Open
Abstract
Ethanol (EtOH) exerts its effects through various protein targets, including transient receptor potential melastatin 7 (TRPM7) channels, which play an essential role in cellular homeostasis. We demonstrated that TRPM7 is expressed in rat brain microvascular endothelial cells (rBMVECs), the major cellular component of the blood-brain barrier (BBB). Heavy alcohol drinking is often associated with HIV infection, however mechanisms underlying alcohol-induced BBB damage and HIV proteins, are not fully understood. We utilized the HIV-1 transgenic (HIV-1Tg) rat to mimic HIV-1 patients on combination anti-retroviral therapy (cART) and demonstrated TRPM7 expression in rBMVECs wass lower in adolescent HIV-1Tg rats compared to control animals, however control and HIV-1Tg rats expressed similar levels at 9 weeks, indicating persistent presence of HIV-1 proteins delayed TRPM7 expression. Binge exposure to EtOH (binge EtOH) decreased TRPM7 expression in control rBMVECs in a concentration-dependent manner, and abolished TRPM7 expression in HIV-1Tg rats. In human BMVECs (hBMVECs), TRPM7 expression was downregulated after treatment with EtOH, HIV-1 proteins, and in combination. Next, we constructed in vitro BBB models using BMVECs and found TRPM7 antagonists enhanced EtOH-mediated BBB integrity changes. Our study demonstrated alcohol decreased TRPM7 expression, whereby TRPM7 could be involved in the mechanisms underlying BBB alcohol-induced damage in HIV-1 patients on cART.
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Affiliation(s)
- Michelle L. Mack
- Institute of NeuroImmune Pharmacology, Seton Hall University, South Orange, NJ 07079, USA
- Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA
| | - Wenfei Huang
- Institute of NeuroImmune Pharmacology, Seton Hall University, South Orange, NJ 07079, USA
- Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA
| | - Sulie L. Chang
- Institute of NeuroImmune Pharmacology, Seton Hall University, South Orange, NJ 07079, USA
- Department of Biological Sciences, Seton Hall University, South Orange, NJ 07079, USA
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9
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Cheng XY, Li SF, Chen Y, Zhao YJ, Hu W, Lu C, Zhou RP. Transient receptor potential melastatin 7 and their modulators. Eur J Pharmacol 2022; 931:175180. [DOI: 10.1016/j.ejphar.2022.175180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 07/20/2022] [Accepted: 08/01/2022] [Indexed: 11/03/2022]
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10
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Audero MM, Prevarskaya N, Fiorio Pla A. Ca 2+ Signalling and Hypoxia/Acidic Tumour Microenvironment Interplay in Tumour Progression. Int J Mol Sci 2022; 23:7377. [PMID: 35806388 PMCID: PMC9266881 DOI: 10.3390/ijms23137377] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/26/2022] [Accepted: 06/27/2022] [Indexed: 01/18/2023] Open
Abstract
Solid tumours are characterised by an altered microenvironment (TME) from the physicochemical point of view, displaying a highly hypoxic and acidic interstitial fluid. Hypoxia results from uncontrolled proliferation, aberrant vascularization and altered cancer cell metabolism. Tumour cellular apparatus adapts to hypoxia by altering its metabolism and behaviour, increasing its migratory and metastatic abilities by the acquisition of a mesenchymal phenotype and selection of aggressive tumour cell clones. Extracellular acidosis is considered a cancer hallmark, acting as a driver of cancer aggressiveness by promoting tumour metastasis and chemoresistance via the selection of more aggressive cell phenotypes, although the underlying mechanism is still not clear. In this context, Ca2+ channels represent good target candidates due to their ability to integrate signals from the TME. Ca2+ channels are pH and hypoxia sensors and alterations in Ca2+ homeostasis in cancer progression and vascularization have been extensively reported. In the present review, we present an up-to-date and critical view on Ca2+ permeable ion channels, with a major focus on TRPs, SOCs and PIEZO channels, which are modulated by tumour hypoxia and acidosis, as well as the consequent role of the altered Ca2+ signals on cancer progression hallmarks. We believe that a deeper comprehension of the Ca2+ signalling and acidic pH/hypoxia interplay will break new ground for the discovery of alternative and attractive therapeutic targets.
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Affiliation(s)
- Madelaine Magalì Audero
- U1003—PHYCEL—Laboratoire de Physiologie Cellulaire, Inserm, University of Lille, Villeneuve d’Ascq, 59000 Lille, France; (M.M.A.); (N.P.)
- Laboratory of Cellular and Molecular Angiogenesis, Department of Life Sciences and Systems Biology, University of Turin, 10123 Turin, Italy
| | - Natalia Prevarskaya
- U1003—PHYCEL—Laboratoire de Physiologie Cellulaire, Inserm, University of Lille, Villeneuve d’Ascq, 59000 Lille, France; (M.M.A.); (N.P.)
| | - Alessandra Fiorio Pla
- U1003—PHYCEL—Laboratoire de Physiologie Cellulaire, Inserm, University of Lille, Villeneuve d’Ascq, 59000 Lille, France; (M.M.A.); (N.P.)
- Laboratory of Cellular and Molecular Angiogenesis, Department of Life Sciences and Systems Biology, University of Turin, 10123 Turin, Italy
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11
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Schmidt E, Narangoda C, Nörenberg W, Egawa M, Rössig A, Leonhardt M, Schaefer M, Zierler S, Kurnikova MG, Gudermann T, Chubanov V. Structural mechanism of TRPM7 channel regulation by intracellular magnesium. Cell Mol Life Sci 2022; 79:225. [PMID: 35389104 PMCID: PMC8989868 DOI: 10.1007/s00018-022-04192-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 01/26/2022] [Accepted: 02/02/2022] [Indexed: 01/03/2023]
Abstract
Zn2+, Mg2+ and Ca2+ are essential divalent cations implicated in many metabolic processes and signalling pathways. An emerging new paradigm is that the organismal balance of these cations predominantly depends on a common gatekeeper, the channel-kinase TRPM7. Despite extensive electrophysiological studies and recent cryo-EM analysis, an open question is how the channel activity of TRPM7 is activated. Here, we performed site-directed mutagenesis of mouse TRPM7 in conjunction with patch-clamp assessment of whole-cell and single-channel activity and molecular dynamics (MD) simulations to show that the side chains of conserved N1097 form an inter-subunit Mg2+ regulatory site located in the lower channel gate of TRPM7. Our results suggest that intracellular Mg2+ binds to this site and stabilizes the TRPM7 channel in the closed state, whereas the removal of Mg2+ favours the opening of TRPM7. Hence, our study identifies the structural underpinnings through which the TRPM7 channel is controlled by cytosolic Mg2+, representing a new structure–function relationship not yet explored among TRPM channels.
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Affiliation(s)
- Eva Schmidt
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Chamali Narangoda
- Chemistry Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Wolfgang Nörenberg
- Rudolf-Boehm Institute of Pharmacology and Toxicology, Leipzig University, Leipzig, Germany
| | - Miyuki Egawa
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Anna Rössig
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany
| | - Marion Leonhardt
- Rudolf-Boehm Institute of Pharmacology and Toxicology, Leipzig University, Leipzig, Germany
| | - Michael Schaefer
- Rudolf-Boehm Institute of Pharmacology and Toxicology, Leipzig University, Leipzig, Germany
| | - Susanna Zierler
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.,Institute of Pharmacology, Johannes Kepler University Linz, Linz, Austria
| | - Maria G Kurnikova
- Chemistry Department, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Thomas Gudermann
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany. .,Comprehensive Pneumology Center, a member of the German Center for Lung Research (DZL), Munich, Germany.
| | - Vladimir Chubanov
- Walther-Straub Institute of Pharmacology and Toxicology, LMU Munich, Munich, Germany.
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12
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Souza Bomfim GH, Niemeyer BA, Lacruz RS, Lis A. On the Connections between TRPM Channels and SOCE. Cells 2022; 11:1190. [PMID: 35406753 PMCID: PMC8997886 DOI: 10.3390/cells11071190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/23/2022] [Accepted: 03/30/2022] [Indexed: 12/02/2022] Open
Abstract
Plasma membrane protein channels provide a passageway for ions to access the intracellular milieu. Rapid entry of calcium ions into cells is controlled mostly by ion channels, while Ca2+-ATPases and Ca2+ exchangers ensure that cytosolic Ca2+ levels ([Ca2+]cyt) are maintained at low (~100 nM) concentrations. Some channels, such as the Ca2+-release-activated Ca2+ (CRAC) channels and voltage-dependent Ca2+ channels (CACNAs), are highly Ca2+-selective, while others, including the Transient Receptor Potential Melastatin (TRPM) family, have broader selectivity and are mostly permeable to monovalent and divalent cations. Activation of CRAC channels involves the coupling between ORAI1-3 channels with the endoplasmic reticulum (ER) located Ca2+ store sensor, Stromal Interaction Molecules 1-2 (STIM1/2), a pathway also termed store-operated Ca2+ entry (SOCE). The TRPM family is formed by 8 members (TRPM1-8) permeable to Mg2+, Ca2+, Zn2+ and Na+ cations, and is activated by multiple stimuli. Recent studies indicated that SOCE and TRPM structure-function are interlinked in some instances, although the molecular details of this interaction are only emerging. Here we review the role of TRPM and SOCE in Ca2+ handling and highlight the available evidence for this interaction.
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Affiliation(s)
- Guilherme H. Souza Bomfim
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY 10010, USA;
| | - Barbara A. Niemeyer
- Department of Molecular Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, 66421 Homburg, Germany;
| | - Rodrigo S. Lacruz
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY 10010, USA;
| | - Annette Lis
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, 66421 Homburg, Germany
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13
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Ji D, Fleig A, Horgen FD, Feng ZP, Sun HS. Modulators of TRPM7 and its potential as a drug target for brain tumours. Cell Calcium 2021; 101:102521. [PMID: 34953296 DOI: 10.1016/j.ceca.2021.102521] [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: 09/29/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 12/14/2022]
Abstract
TRPM7 is a non-selective divalent cation channel with an alpha-kinase domain. Corresponding with its broad expression, TRPM7 has a role in a wide range of cell functions, including proliferation, migration, and survival. Growing evidence shows that TRPM7 is also aberrantly expressed in various cancers, including brain cancers. Because ion channels have widespread tissue distribution and result in extensive physiological consequences when dysfunctional, these proteins can be compelling drug targets. In fact, ion channels comprise the third-largest drug target type, following enzymes and receptors. Literature has shown that suppression of TRPM7 results in inhibition of migration, invasion, and proliferation in several human brain tumours. Therefore, TRPM7 presents a potential target for therapeutic brain tumour interventions. This article reviews current literature on TRPM7 as a potential drug target in the context of brain tumours and provides an overview of various selective and non-selective modulators of the channel relevant to pharmacology, oncology, and ion channel function.
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Affiliation(s)
- Delphine Ji
- Department of Surgery, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8; Department of Physiology, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8
| | - Andrea Fleig
- Center for Biomedical Research at The Queen's Medical Center and John A. Burns School of Medicine and Cancer Center at the University of Hawaii, Honolulu, Hawaii 96813, USA
| | - F David Horgen
- Department of Natural Sciences, Hawaii Pacific University, Kaneohe, Hawaii 96744, USA
| | - Zhong-Ping Feng
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8.
| | - Hong-Shuo Sun
- Department of Surgery, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8; Department of Physiology, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8; Department of Pharmacology, Temerty Faculty of Medicine, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada M5S 1A8; Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario, Canada M5S 3M2.
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14
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Chokshi R, Bennett O, Zhelay T, Kozak JA. NSAIDs Naproxen, Ibuprofen, Salicylate, and Aspirin Inhibit TRPM7 Channels by Cytosolic Acidification. Front Physiol 2021; 12:727549. [PMID: 34733174 PMCID: PMC8558630 DOI: 10.3389/fphys.2021.727549] [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: 06/18/2021] [Accepted: 09/10/2021] [Indexed: 01/23/2023] Open
Abstract
Non-steroidal anti-inflammatory drugs (NSAIDs) are used for relieving pain and inflammation accompanying numerous disease states. The primary therapeutic mechanism of these widely used drugs is the inhibition of cyclooxygenase 1 and 2 (COX1, 2) enzymes that catalyze the conversion of arachidonic acid into prostaglandins. At higher doses, NSAIDs are used for prevention of certain types of cancer and as experimental treatments for Alzheimer’s disease. In the immune system, various NSAIDs have been reported to influence neutrophil function and lymphocyte proliferation, and affect ion channels and cellular calcium homeostasis. Transient receptor potential melastatin 7 (TRPM7) cation channels are highly expressed in T lymphocytes and are inhibited by Mg2+, acidic pH, and polyamines. Here, we report a novel effect of naproxen, ibuprofen, salicylate, and acetylsalicylate on TRPM7. At concentrations of 3–30mM, they reversibly inhibited TRPM7 channel currents. By measuring intracellular pH with the ratiometric indicator BCECF, we found that at 300μM to 30mM, these NSAIDs reversibly acidified the cytoplasm in a concentration-dependent manner, and propose that TRPM7 channel inhibition is a consequence of cytosolic acidification, rather than direct. NSAID inhibition of TRPM7 channels was slow, voltage-independent, and displayed use-dependence, increasing in potency upon repeated drug applications. The extent of channel inhibition by salicylate strongly depended on cellular PI(4,5)P2 levels, as revealed when this phospholipid was depleted with voltage-sensitive lipid phosphatase (VSP). Salicylate inhibited heterologously expressed wildtype TRPM7 channels but not the S1107R variant, which is insensitive to cytosolic pH, Mg2+, and PI(4,5)P2 depletion. NSAID-induced acidification was also observed in Schneider 2 cells from Drosophila, an organism that lacks orthologous COX genes, suggesting that this effect is unrelated to COX enzyme activity. A 24-h exposure to 300μM–10mM naproxen resulted in a concentration-dependent reduction in cell viability. In addition to TRPM7, the described NSAID effect would be expected to apply to other ion channels and transporters sensitive to intracellular pH.
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Affiliation(s)
- Rikki Chokshi
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine, College of Science and Mathematics, Wright State University, Dayton, OH, United States
| | - Orville Bennett
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine, College of Science and Mathematics, Wright State University, Dayton, OH, United States
| | - Tetyana Zhelay
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine, College of Science and Mathematics, Wright State University, Dayton, OH, United States
| | - J Ashot Kozak
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine, College of Science and Mathematics, Wright State University, Dayton, OH, United States
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15
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Rojas J, Hinostroza F, Vergara S, Pinto-Borguero I, Aguilera F, Fuentes R, Carvacho I. Knockin' on Egg's Door: Maternal Control of Egg Activation That Influences Cortical Granule Exocytosis in Animal Species. Front Cell Dev Biol 2021; 9:704867. [PMID: 34540828 PMCID: PMC8446563 DOI: 10.3389/fcell.2021.704867] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 08/16/2021] [Indexed: 12/23/2022] Open
Abstract
Fertilization by multiple sperm leads to lethal chromosomal number abnormalities, failed embryo development, and miscarriage. In some vertebrate and invertebrate eggs, the so-called cortical reaction contributes to their activation and prevents polyspermy during fertilization. This process involves biogenesis, redistribution, and subsequent accumulation of cortical granules (CGs) at the female gamete cortex during oogenesis. CGs are oocyte- and egg-specific secretory vesicles whose content is discharged during fertilization to block polyspermy. Here, we summarize the molecular mechanisms controlling critical aspects of CG biology prior to and after the gametes interaction. This allows to block polyspermy and provide protection to the developing embryo. We also examine how CGs form and are spatially redistributed during oogenesis. During egg activation, CG exocytosis (CGE) and content release are triggered by increases in intracellular calcium and relies on the function of maternally-loaded proteins. We also discuss how mutations in these factors impact CG dynamics, providing unprecedented models to investigate the genetic program executing fertilization. We further explore the phylogenetic distribution of maternal proteins and signaling pathways contributing to CGE and egg activation. We conclude that many important biological questions and genotype–phenotype relationships during fertilization remain unresolved, and therefore, novel molecular players of CG biology need to be discovered. Future functional and image-based studies are expected to elucidate the identity of genetic candidates and components of the molecular machinery involved in the egg activation. This, will open new therapeutic avenues for treating infertility in humans.
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Affiliation(s)
- Japhet Rojas
- Laboratorio Fisiología de la Reproducción, Departamento de Biología y Química, Facultad de Ciencias Básicas, Universidad Católica del Maule, Talca, Chile.,Escuela de Ingeniería en Biotecnología, Facultad de Ciencias Agrarias y Forestales, Universidad Católica del Maule, Talca, Chile
| | - Fernando Hinostroza
- Laboratorio Fisiología de la Reproducción, Departamento de Biología y Química, Facultad de Ciencias Básicas, Universidad Católica del Maule, Talca, Chile.,Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca, Chile.,Centro de Investigación en Neuropsicología y Neurociencias Cognitivas, Facultad de Ciencias de la Salud, Universidad Católica del Maule, Talca, Chile
| | - Sebastián Vergara
- Laboratorio Fisiología de la Reproducción, Departamento de Biología y Química, Facultad de Ciencias Básicas, Universidad Católica del Maule, Talca, Chile.,Escuela de Ingeniería en Biotecnología, Facultad de Ciencias Agrarias y Forestales, Universidad Católica del Maule, Talca, Chile
| | - Ingrid Pinto-Borguero
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Felipe Aguilera
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Ricardo Fuentes
- Departamento de Biología Celular, Facultad de Ciencias Biológicas, Universidad de Concepción, Concepción, Chile
| | - Ingrid Carvacho
- Laboratorio Fisiología de la Reproducción, Departamento de Biología y Química, Facultad de Ciencias Básicas, Universidad Católica del Maule, Talca, Chile
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16
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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: 11] [Impact Index Per Article: 3.7] [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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17
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TRPM7-Mediated Calcium Transport in HAT-7 Ameloblasts. Int J Mol Sci 2021; 22:ijms22083992. [PMID: 33924361 PMCID: PMC8069123 DOI: 10.3390/ijms22083992] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/05/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023] Open
Abstract
TRPM7 plays an important role in cellular Ca2+, Zn2+ and Mg2+ homeostasis. TRPM7 channels are abundantly expressed in ameloblasts and, in the absence of TRPM7, dental enamel is hypomineralized. The potential role of TRPM7 channels in Ca2+ transport during amelogenesis was investigated in the HAT-7 rat ameloblast cell line. The cells showed strong TRPM7 mRNA and protein expression. Characteristic TRPM7 transmembrane currents were observed, which increased in the absence of intracellular Mg2+ ([Mg2+]i), were reduced by elevated [Mg2+]i, and were inhibited by the TRPM7 inhibitors NS8593 and FTY720. Mibefradil evoked similar currents, which were suppressed by elevated [Mg2+]i, reducing extracellular pH stimulated transmembrane currents, which were inhibited by FTY720. Naltriben and mibefradil both evoked Ca2+ influx, which was further enhanced by the acidic intracellular conditions. The SOCE inhibitor BTP2 blocked Ca2+ entry induced by naltriben but not by mibefradil. Thus, in HAT-7 cells, TRPM7 may serves both as a potential modulator of Orai-dependent Ca2+ uptake and as an independent Ca2+ entry pathway sensitive to pH. Therefore, TRPM7 may contribute directly to transepithelial Ca2+ transport in amelogenesis.
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18
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Hossain Saad MZ, Xiang L, Liao YS, Reznikov LR, Du J. The Underlying Mechanism of Modulation of Transient Receptor Potential Melastatin 3 by protons. Front Pharmacol 2021; 12:632711. [PMID: 33603674 PMCID: PMC7884864 DOI: 10.3389/fphar.2021.632711] [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: 11/23/2020] [Accepted: 01/04/2021] [Indexed: 12/03/2022] Open
Abstract
Transient receptor potential melastatin 3 channel (TRPM3) is a calcium-permeable nonselective cation channel that plays an important role in modulating glucose homeostasis in the pancreatic beta cells. However, how TRPM3 is regulated under physiological and pathological conditions is poorly understood. In this study, we found that both intracellular and extracellular protons block TRPM3 through its binding sites in the pore region. We demonstrated that external protons block TRPM3 with an inhibitory pH50 of 5.5. whereas internal protons inhibit TRPM3 with an inhibitory pH50 of 6.9. We identified three titratable residues, D1059, D1062, and D1073, at the vestibule of the channel pore that contributes to pH sensitivity. The mutation of D1073Q reduced TRPM3 current by low external pH 5.5 from 62 ± 3% in wildtype to 25 ± 6.0% in D1073Q mutant. These results indicate that D1073 is essential for pH sensitivity. In addition, we found that a single mutation of D1059 or D1062 enhanced pH sensitivity. In summary, our findings identify molecular determinants respionsible for the pH regulation of TRPM3. The inhibition of TRPM3 by protons may indicate an endogenous mechanism governing TRPM3 gating and its physiological/pathological functions.
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Affiliation(s)
- Md Zubayer Hossain Saad
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States.,Department of Biological Sciences, University of Toledo, Toledo, OH, United States
| | - Liuruimin Xiang
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States.,Department of Biological Sciences, University of Toledo, Toledo, OH, United States.,Program of Neuroscience, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Yan-Shin Liao
- Department of Physiological Sciences, University of Florida, Gainesville, FL, United States
| | - Leah R Reznikov
- Department of Physiological Sciences, University of Florida, Gainesville, FL, United States
| | - Jianyang Du
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, United States.,Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, United States
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19
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Beesetty P, Rockwood J, Kaitsuka T, Zhelay T, Hourani S, Matsushita M, Kozak JA. Phagocytic activity of splenic macrophages is enhanced and accompanied by cytosolic alkalinization in TRPM7 kinase-dead mice. FEBS J 2021; 288:3585-3601. [PMID: 33354894 DOI: 10.1111/febs.15683] [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: 06/01/2020] [Revised: 10/29/2020] [Accepted: 12/21/2020] [Indexed: 12/31/2022]
Abstract
Transient receptor potential melastatin 7 (TRPM7) is a unique protein functioning as a cation channel as well as a serine/threonine kinase and is highly expressed in immune cells such as lymphocytes and macrophages. TRPM7 kinase-dead (KD) mouse model has been used to investigate the role of this protein in immune cells; these animals display moderate splenomegaly and ectopic hemopoiesis. The basal TRPM7 current magnitudes in peritoneal macrophages isolated from KD mice were higher; however, the maximum currents, achieved after cytoplasmic Mg2+ washout, were not different. In the present study, we investigated the consequences of TRPM7 kinase inactivation in splenic and peritoneal macrophages. We measured the basal phagocytic activity of splenic macrophages using fluorescent latex beads, pHrodo zymosan bioparticles, and opsonized red blood cells. KD macrophages phagocytized more efficiently and had slightly higher baseline calcium levels compared to WT cells. We found no obvious differences in store-operated Ca2+ entry between WT and KD macrophages. By contrast, the resting cytosolic pH in KD macrophages was significantly more alkaline than in WT. Pharmacological blockade of sodium hydrogen exchanger 1 (NHE1) reversed the cytosolic alkalinization and reduced phagocytosis in KD macrophages. Basal TRPM7 channel activity in KD macrophages was also reduced after NHE1 blockade. Cytosolic Mg2+ sensitivity of TRPM7 channels measured in peritoneal macrophages was similar in WT and KD mice. The higher basal TRPM7 channel activity in KD macrophages is likely due to alkalinization. Our results identify a novel role for TRPM7 kinase as a suppressor of basal phagocytosis and a regulator of cellular pH.
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Affiliation(s)
- Pavani Beesetty
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, USA
| | - Jananie Rockwood
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, USA
| | - Taku Kaitsuka
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Japan
| | - Tetyana Zhelay
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, USA
| | - Siham Hourani
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, USA
| | - Masayuki Matsushita
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - J Ashot Kozak
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, USA
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20
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Liu M, Dudley SC. Magnesium, Oxidative Stress, Inflammation, and Cardiovascular Disease. Antioxidants (Basel) 2020; 9:E907. [PMID: 32977544 PMCID: PMC7598282 DOI: 10.3390/antiox9100907] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/15/2022] Open
Abstract
Hypomagnesemia is commonly observed in heart failure, diabetes mellitus, hypertension, and cardiovascular diseases. Low serum magnesium (Mg) is a predictor for cardiovascular and all-cause mortality and treating Mg deficiency may help prevent cardiovascular disease. In this review, we discuss the possible mechanisms by which Mg deficiency plays detrimental roles in cardiovascular diseases and review the results of clinical trials of Mg supplementation for heart failure, arrhythmias and other cardiovascular diseases.
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Affiliation(s)
- Man Liu
- Division of Cardiology, Department of Medicine, the Lillehei Heart Institute, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA
| | - Samuel C. Dudley
- Division of Cardiology, Department of Medicine, the Lillehei Heart Institute, University of Minnesota at Twin Cities, Minneapolis, MN 55455, USA
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21
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Mellott A, Rockwood J, Zhelay T, Luu CT, Kaitsuka T, Kozak JA. TRPM7 channel activity in Jurkat T lymphocytes during magnesium depletion and loading: implications for divalent metal entry and cytotoxicity. Pflugers Arch 2020; 472:1589-1606. [PMID: 32964285 DOI: 10.1007/s00424-020-02457-3] [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: 05/15/2020] [Revised: 08/26/2020] [Accepted: 08/28/2020] [Indexed: 12/14/2022]
Abstract
TRPM7 is a cation channel-protein kinase highly expressed in T lymphocytes and other immune cells. It has been proposed to constitute a cellular entry pathway for Mg2+ and divalent metal cations such as Ca2+, Zn2+, Cd2+, Mn2+, and Ni2+. TRPM7 channels are inhibited by cytosolic Mg2+, rendering them largely inactive in intact cells. The dependence of channel activity on extracellular Mg2+ is less well studied. Here, we measured native TRPM7 channel activity in Jurkat T cells maintained in external Mg2+ concentrations varying between 400 nM and 1.4 mM for 1-3 days, obtaining an IC50 value of 54 μM. Maintaining the cells in 400 nM or 8 μM [Mg2+]o resulted in almost complete activation of TRPM7 in intact cells, due to cytosolic Mg2+ depletion. A total of 1.4 mM [Mg2+]o was sufficient to fully eliminate the basal current. Submillimolar concentrations of amiloride prevented cellular Mg2+ depletion but not loading. We investigated whether the cytotoxicity of TRPM7 permeant metal ions Ni2+, Zn2+, Cd2+, Co2+, Mn2+, Sr2+, and Ba2+ requires TRPM7 channel activity. Mg2+ loading modestly reduced cytotoxicity of Zn2+, Co2+, Ni2+, and Mn2+ but not of Cd2+. Channel blocker NS8593 reduced Co2+ and Mn2+ but not Cd2+ or Zn2+ cytotoxicity and interfered with Mg2+ loading as evaluated by TRPM7 channel basal activity. Ba2+ and Sr2+ were neither detectably toxic nor permeant through the plasma membrane. These results indicate that in Jurkat T cells, entry of toxic divalent metal cations primarily occurs through pathways distinct from TRPM7. By contrast, we found evidence that Mg2+ entry requires TRPM7 channels.
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Affiliation(s)
- Alayna Mellott
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Jananie Rockwood
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Tetyana Zhelay
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Charles Tuan Luu
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA
| | - Taku Kaitsuka
- School of Pharmacy in Fukuoka, International University of Health and Welfare, Enokizu 137-1, Okawa, Fukuoka, Japan
| | - J Ashot Kozak
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, OH, 45435, USA.
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22
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Inoue H, Inazu M, Konishi M, Yokoyama U. Functional expression of TRPM7 as a Ca 2+ influx pathway in adipocytes. Physiol Rep 2020; 7:e14272. [PMID: 31650715 PMCID: PMC6813326 DOI: 10.14814/phy2.14272] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 09/20/2019] [Accepted: 10/04/2019] [Indexed: 02/01/2023] Open
Abstract
In adipocytes, intracellular Ca2+ and Mg2+ modulates physiological functions, such as insulin action and the secretion of adipokines. TRPM7 is a Ca2+/Mg2+‐permeable non‐selective cation channel. TRPM7 mRNA is highly expressed in adipose tissue, however, its functional expression in adipocytes remains to be elucidated. In this study, we demonstrated for the first time that TRPM7 was functionally expressed in both freshly isolated white adipocytes and in 3T3‐L1 adipocytes differentiated from a 3T3‐L1 pre‐adipocyte cell line by whole‐cell patch‐clamp recordings. Consistent with known properties of TRPM7 current, the current in adipocytes was activated by the elimination of extracellular divalent cations and the reduction of intracellular free Mg2+ concentrations, and was inhibited by the TRPM7 inhibitors, 2‐aminoethyl diphenylborinate (2‐APB), hydrogen peroxide (H2O2), N‐methyl maleimide (NMM), NS8593, and 2‐amino‐2‐[2‐(4‐octylphenyl)ethyl]‐1,3‐propanediol (FTY720). Treatment with small‐interfering (si) RNA targeting TRPM7 resulted in a reduction in the current to 23 ± 7% of nontargeting siRNA‐treated adipocytes. Moreover a TRPM7 activator, naltriben, increased the TRPM7‐like current and [Ca2+]i in 3T3‐L1 adipocytes but not in TRPM7‐knockdown adipocytes. These findings indicate that TRPM7 is functionally expressed, and plays a role as a Ca2+ influx pathway in adipocytes.
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Affiliation(s)
- Hana Inoue
- Department of Physiology, Tokyo Medical University, Tokyo, Japan
| | - Masato Inazu
- Institute of Medical Science, Tokyo Medical University, Tokyo, Japan
| | - Masato Konishi
- Department of Physiology, Tokyo Medical University, Tokyo, Japan
| | - Utako Yokoyama
- Department of Physiology, Tokyo Medical University, Tokyo, Japan
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23
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Tian Y, Yang T, Yu S, Liu C, He M, Hu C. Prostaglandin E2 increases migration and proliferation of human glioblastoma cells by activating transient receptor potential melastatin 7 channels. J Cell Mol Med 2018; 22:6327-6337. [PMID: 30338939 PMCID: PMC6237613 DOI: 10.1111/jcmm.13931] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 08/30/2018] [Indexed: 12/26/2022] Open
Abstract
Recent studies showed that both prostaglandin E2 (PGE2) and transient receptor potential melastatin 7 (TRPM7) play important roles in migration and proliferation of human glioblastoma cells. In this study, we tested the association between PGE2 and TRPM7. We found that PGE2 increased TRPM7 currents in HEK293 and human glioblastoma A172 cells. The PGE2 EP3 receptor antagonist L‐798106 abrogated the PGE2 stimulatory effect, while EP3 agonist 17‐phenyl trinor prostaglandin E2 (17‐pt‐PGE2) mimicked the effect of PEG2 on TRPM7. The TRPM7 phosphotransferase activity‐deficient mutation, K1646R had no effect on PGE2 induced increase of TRPM7 currents. Inhibition of protein kinase A (PKA) activity by Rp‐cAMP increased TRPM7 currents. TRPM7 PKA phosphorylation site mutation S1269A abolished the PGE2 effect on TRPM7 currents. PGE2 increased both mRNA and membrane protein expression of TRPM7 in A172 cells. Knockdown of TRPM7 by shRNA abrogated the PGE2 stimulated migration and proliferation of A172 cells. Blockage of TRPM7 with 2‐aminoethoxydiphenyl borate (2‐APB) or NS8593 had a similar effect as TRPM7‐shRNA. In conclusion, our results demonstrate that PGE2 activates TRPM7 via EP3/PKA signalling pathway, and that PGE2 enhances migration and proliferation of human glioblastoma cells by up‐regulation of the TRPM7 channel.
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Affiliation(s)
- Yafei Tian
- Department of Physiology and Biophysics, School of Life Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Tingting Yang
- Department of Physiology and Biophysics, School of Life Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Shuntai Yu
- Department of Physiology and Biophysics, School of Life Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Cuiyun Liu
- Department of Physiology and Biophysics, School of Life Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Min He
- Department of Physiology and Biophysics, School of Life Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Changlong Hu
- Department of Physiology and Biophysics, School of Life Sciences, Institutes of Brain Science, Fudan University, Shanghai, China
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24
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Zhelay T, Wieczerzak KB, Beesetty P, Alter GM, Matsushita M, Kozak JA. Depletion of plasma membrane-associated phosphoinositides mimics inhibition of TRPM7 channels by cytosolic Mg 2+, spermine, and pH. J Biol Chem 2018; 293:18151-18167. [PMID: 30305398 PMCID: PMC6254349 DOI: 10.1074/jbc.ra118.004066] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 10/04/2018] [Indexed: 12/20/2022] Open
Abstract
Transient receptor potential cation channel subfamily M member 7 (TRPM7) is an ion channel/protein kinase belonging to the TRP melastatin and eEF2 kinase families. Under physiological conditions, most native TRPM7 channels are inhibited by cytoplasmic Mg2+, protons, and polyamines. Currents through these channels (ITRPM7) are robustly potentiated when the cell interior is exchanged with low Mg2+-containing buffers. ITRPM7 is also potentiated by phosphatidyl inositol bisphosphate (PI(4,5)P2) and suppressed by its hydrolysis. Here we characterized internal Mg2+- and pH-mediated inhibition of TRPM7 channels in HEK293 cells overexpressing WT voltage-sensing phospholipid phosphatase (VSP) or its catalytically inactive variant VSP-C363S. VSP-mediated depletion of membrane phosphoinositides significantly increased channel sensitivity to Mg2+ and pH. Proton concentrations that were too low to inhibit ITRPM7 when the VSP-C363S variant was expressed (pH 8.2) became inhibitory in WT VSP-expressing cells. At pH 6.5, protons inhibited ITRPM7 both in WT and VSP C363S-expressing cells but with a faster time course in the WT VSP-expressing cells. Inhibition by 150 μm Mg2+ was also significantly faster in the WT VSP-expressing cells. Cellular PI(4,5)P2 depletion increased the sensitivity of TRPM7 channels to the inhibitor 2-aminoethyl diphenyl borinate, which acidifies the cytosol. Single substitutions at Ser-1107 of TRPM7, reducing its sensitivity to Mg2+, also decreased its inhibition by spermine and acidic pH. Furthermore, these channel variants were markedly less sensitive to VSP-mediated PI(4,5)P2 depletion than the WT. We conclude that the internal Mg2+-, polyamine-, and pH-mediated inhibition of TRPM7 channels is not direct but, rather, reflects electrostatic screening and resultant disruption of PI(4,5)P2-channel interactions.
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Affiliation(s)
- Tetyana Zhelay
- From the Departments of Neuroscience, Cell Biology, and Physiology and
| | | | - Pavani Beesetty
- From the Departments of Neuroscience, Cell Biology, and Physiology and
| | - Gerald M Alter
- Biochemistry and Molecular Biology, Wright State University, Dayton, Ohio 45435 and
| | - Masayuki Matsushita
- the Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, Okinawa 903-0215, Japan
| | - J Ashot Kozak
- From the Departments of Neuroscience, Cell Biology, and Physiology and.
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25
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Nadolni W, Zierler S. The Channel-Kinase TRPM7 as Novel Regulator of Immune System Homeostasis. Cells 2018; 7:cells7080109. [PMID: 30126133 PMCID: PMC6115979 DOI: 10.3390/cells7080109] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 08/13/2018] [Accepted: 08/13/2018] [Indexed: 12/16/2022] Open
Abstract
The enzyme-coupled transient receptor potential channel subfamily M member 7, TRPM7, has been associated with immunity and immune cell signalling. Here, we review the role of this remarkable signalling protein in lymphocyte proliferation, differentiation, activation and survival. We also discuss its role in mast cell, neutrophil and macrophage function and highlight the potential of TRPM7 to regulate immune system homeostasis. Further, we shed light on how the cellular signalling cascades involving TRPM7 channel and/or kinase activity culminate in pathologies as diverse as allergic hypersensitivity, arterial thrombosis and graft versus host disease (GVHD), stressing the need for TRPM7 specific pharmacological modulators.
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Affiliation(s)
- Wiebke Nadolni
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Goethestr. 33, 80336 Munich, Germany.
| | - Susanna Zierler
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Goethestr. 33, 80336 Munich, Germany.
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26
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Ethanol's Effects on Transient Receptor Potential Channel Expression in Brain Microvascular Endothelial Cells. J Neuroimmune Pharmacol 2018; 13:498-508. [PMID: 29987591 DOI: 10.1007/s11481-018-9796-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 06/28/2018] [Indexed: 12/14/2022]
Abstract
Ethanol (EtOH), the main ingredient in alcoholic beverages, is well known for its behavioral, physiological, and immunosuppressive effects. There is evidence that EtOH acts through protein targets to exert its physiological effects; however, the mechanisms underlying EtOH's effects on inflammatory processes, particularly at the blood-brain barrier (BBB), are still poorly understood. Transient receptor potential (TRP) channels, the vanguards of human sensory systems, are novel molecular receptors significantly affected by EtOH, and are heavily expressed in brain microvascular endothelial cells (BMVECs), one of the cellular constituents of the BBB. EtOH's actions on endothelial TRP channels could affect intracellular Ca2+ and Mg2+ dynamics, which mediate leukocyte adhesion to endothelial cells and endothelial permeability at the BBB, thus altering immune and inflammatory responses. We examined the basal expression profiles of all 29 known mammalian TRP channels in mouse BMVECs and determined both EtOH concentration- and time-dependent effects on TRP expression using a PCR array. We also generated an in vitro BBB model to examine the involvement of a chosen TRP channel, TRP melastatin 7 (TRPM7), in EtOH-mediated alteration of BBB permeability. With the exception of the akyrin subfamily, members of five TRP subfamilies were expressed in mouse BMVECs, and their expression levels were modulated by EtOH in a concentration-dependent manner. In the in vitro BBB model, TRPM7 antagonists further enhanced EtOH-mediated alteration of BBB permeability. Because of the diversity of TRP channels in BMVECs that regulate cellular processes, EtOH can affect Ca2+/Mg2+ signaling, immune responses, lysosomal functions as well as BBB integrity.
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27
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Boedtkjer E. Acid-base regulation and sensing: Accelerators and brakes in metabolic regulation of cerebrovascular tone. J Cereb Blood Flow Metab 2018; 38:588-602. [PMID: 28984162 PMCID: PMC5888856 DOI: 10.1177/0271678x17733868] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 08/10/2017] [Accepted: 09/06/2017] [Indexed: 12/29/2022]
Abstract
Metabolic regulation of cerebrovascular tone directs blood flow to areas of increased neuronal activity and during disease states partially compensates for insufficient perfusion by enhancing blood flow in collateral blood vessels. Acid-base disturbances frequently occur as result of enhanced metabolism or insufficient blood supply, but despite definitive evidence that acid-base disturbances alter arterial tone, effects of individual acid-base equivalents and the underlying signaling mechanisms are still being debated. H+ is an important intra- and extracellular messenger that modifies cerebrovascular tone. In addition, low extracellular [HCO3-] promotes cerebrovascular contraction through an endothelium-dependent mechanism. CO2 alters arterial tone development via changes in intra- and extracellular pH but it is still controversial whether CO2 also has direct vasomotor effects. Vasocontractile responses to low extracellular [HCO3-] and acute CO2-induced decreases in intracellular pH can counteract H+-mediated vasorelaxation during metabolic and respiratory acidosis, respectively, and may thereby reduce the risk of capillary damage and cerebral edema that could be consequences of unopposed vasodilation. In this review, the signaling mechanisms for acid-base equivalents in cerebral arteries and the mechanisms of intracellular pH control in the arterial wall are discussed in the context of metabolic regulation of cerebrovascular tone and local perfusion.
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Affiliation(s)
- Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
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28
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29
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Inactivation of TRPM7 kinase in mice results in enlarged spleens, reduced T-cell proliferation and diminished store-operated calcium entry. Sci Rep 2018; 8:3023. [PMID: 29445164 PMCID: PMC5813043 DOI: 10.1038/s41598-018-21004-w] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/29/2018] [Indexed: 12/20/2022] Open
Abstract
T lymphocytes enlarge (blast) and proliferate in response to antigens in a multistep program that involves obligatory cytosolic calcium elevations. Store-operated calcium entry (SOCE) pathway is the primary source of Ca2+ in these cells. Here, we describe a novel modulator of blastogenesis, proliferation and SOCE: the TRPM7 channel kinase. TRPM7 kinase-dead (KD) K1646R knock-in mice exhibited splenomegaly and impaired blastogenic responses elicited by PMA/ionomycin or anti-CD3/CD28 antibodies. Splenic T-cell proliferation in vitro was weaker in the mutant compared to wildtype littermates. TRPM7 current magnitudes in WT and KD mouse T cells were, however, similar. We tested the dependence of T-cell proliferation on external Ca2+ and Mg2+ concentrations. At a fixed [Mg2+o] of ~0.4 mM, Ca2+o stimulated proliferation with a steep concentration dependence and vice versa, at a fixed [Ca2+o] of ~0.4 mM, Mg2+o positively regulated proliferation but with a shallower dependence. Proliferation was significantly lower in KD mouse than in wildtype at all Ca2+ and Mg2+ concentrations. Ca2+ elevations elicited by anti-CD3 antibody were diminished in KD mutant T cells and SOCE measured in activated KD splenocytes was reduced. These results demonstrate that a functional TRPM7 kinase supports robust SOCE, blastogenesis and proliferation, whereas its inactivation suppresses these cellular events.
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30
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Ogata K, Tsumuraya T, Oka K, Shin M, Okamoto F, Kajiya H, Katagiri C, Ozaki M, Matsushita M, Okabe K. The crucial role of the TRPM7 kinase domain in the early stage of amelogenesis. Sci Rep 2017; 7:18099. [PMID: 29273814 PMCID: PMC5741708 DOI: 10.1038/s41598-017-18291-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 12/07/2017] [Indexed: 12/15/2022] Open
Abstract
Transient receptor potential melastatin-7 (TRPM7) is a bi-functional protein containing a kinase domain fused to an ion channel. TRPM7 is highly expressed in ameloblasts during tooth development. Here we show that TRPM7 kinase-inactive knock-in mutant mice (TRPM7 KR mice) exhibited small enamel volume with opaque white-colored incisors. The TRPM7 channel function of ameloblast-lineage cells from TRPM7 KR mice was normal. Interestingly, phosphorylation of intracellular molecules including Smad1/5/9, p38 and cAMP response element binding protein (CREB) was inhibited in ameloblasts from TRPM7 KR mice at the pre-secretory stage. An immunoprecipitation assay showed that CREB was bound to TRPM7, suggesting that direct phosphorylation of CREB by TRPM7 was inhibited in ameloblast-lineage cells from TRPM7 KR mice. These results indicate that the function of the TRPM7 kinase domain plays an important role in ameloblast differentiation, independent of TRPM7 channel activity, via phosphorylation of CREB.
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Affiliation(s)
- Kayoko Ogata
- Section of Cellular Physiology, Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan.,Section of Pediatric Dentistry, Department of Oral Growth and Development, Fukuoka Dental College, Fukuoka, Japan
| | - Tomoyuki Tsumuraya
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Kyoko Oka
- Section of Pediatric Dentistry, Department of Oral Growth and Development, Fukuoka Dental College, Fukuoka, Japan.
| | - Masashi Shin
- Section of Cellular Physiology, Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Fujio Okamoto
- Section of Cellular Physiology, Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Hiroshi Kajiya
- Section of Cellular Physiology, Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
| | - Chiaki Katagiri
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Masao Ozaki
- Section of Pediatric Dentistry, Department of Oral Growth and Development, Fukuoka Dental College, Fukuoka, Japan
| | - Masayuki Matsushita
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan
| | - Koji Okabe
- Section of Cellular Physiology, Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, Fukuoka, Japan
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31
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Assessment of TRPM7 functions by drug-like small molecules. Cell Calcium 2017; 67:166-173. [DOI: 10.1016/j.ceca.2017.03.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 03/08/2017] [Indexed: 12/28/2022]
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32
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Song C, Bae Y, Jun J, Lee H, Kim ND, Lee KB, Hur W, Park JY, Sim T. Identification of TG100-115 as a new and potent TRPM7 kinase inhibitor, which suppresses breast cancer cell migration and invasion. Biochim Biophys Acta Gen Subj 2017; 1861:947-957. [PMID: 28161478 DOI: 10.1016/j.bbagen.2017.01.034] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 01/26/2017] [Accepted: 01/31/2017] [Indexed: 02/08/2023]
Abstract
BACKGROUND Transient receptor potential melastatin 7 (TRPM7) regulates breast cancer cell proliferation, migration, invasion and metastasis in its ion channel- and kinase domain-dependent manner. The pharmacological effects of TRPM7 ion channel inhibitors on breast cancer cells have been studied, but little is known about the effects of TRPM7 kinase domain inhibitors due to lack of potent TRPM7 kinase inhibitors. METHODS Screening was performed by using TRPM7 kinase assay. Effects of TG100-115 on breast cancer cell proliferation, migration, invasion, myosin IIA phosphorylation, and TRPM7 ion channel activity were assessed by using MTT, wound healing, transwell assay, Western blotting, and patch clamping, respectively. RESULTS We found that CREB peptide is a potent substrate for the TR-FRET based TRPM7 kinase assay. Using this method, we discovered a new and potent TRPM7 kinase inhibitor, TG100-115. TG100-115 inhibited TRPM7 kinase activity in an ATP competitive fashion with over 70-fold stronger activity than that of rottlerin, known as a TRPM7 kinase inhibitor. TG100-115 has little effect on proliferation of MDA-MB-231 cells, but significantly decreases cell migration and invasion. Moreover, TG100-115 inhibits TRPM7 kinase regulated phosphorylation of the myosin IIA heavy chain and phosphorylation of focal adhesion kinase. TG100-115 also suppressed TRPM7 ion channel activity. CONCLUSIONS TG100-115 can be used as a potent TRPM7 kinase inhibitor and a potent inhibitor of breast cancer cell migration. GENERAL SIGNIFICANCE TG100-115 could be a useful tool for studying the pharmacological effects of TRPM7 kinase activity aimed at providing insight into new therapeutic approaches to the treatment of breast cancer.
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Affiliation(s)
- Chiman Song
- Chemical Kinomics Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Yeonju Bae
- School of Biosystem and Biomedical Science, College of Health Science, Korea University, Seoul, 02841, Republic of Korea
| | - JinJoo Jun
- Chemical Kinomics Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Hyomin Lee
- Chemical Kinomics Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; Department of Biological Chemistry, Korea University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Nam Doo Kim
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 41061, Republic of Korea
| | - Kyung-Bok Lee
- Division of Life Science, Korea Basic Science Institute, Daejeon 34133, Republic of Korea
| | - Wooyoung Hur
- Chemical Kinomics Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; Department of Biological Chemistry, Korea University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Jae-Yong Park
- School of Biosystem and Biomedical Science, College of Health Science, Korea University, Seoul, 02841, Republic of Korea
| | - Taebo Sim
- Chemical Kinomics Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea; KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Republic of Korea.
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33
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Diaz-Franulic I, Poblete H, Miño-Galaz G, González C, Latorre R. Allosterism and Structure in Thermally Activated Transient Receptor Potential Channels. Annu Rev Biophys 2016; 45:371-98. [DOI: 10.1146/annurev-biophys-062215-011034] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ignacio Diaz-Franulic
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago 8370146, Chile
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2366103, Chile; ,
- Fraunhofer Chile Research, Las Condes 7550296, Santiago, Chile
| | - Horacio Poblete
- Institute of Computational Comparative Medicine, Nanotechnology Innovation Center of Kansas State, Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas 66506-5802
| | - Germán Miño-Galaz
- Center for Bioinformatics and Integrative Biology, Facultad de Ciencias Biológicas, Universidad Andres Bello, Santiago 8370146, Chile
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2366103, Chile; ,
| | - Carlos González
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2366103, Chile; ,
| | - Ramón Latorre
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2366103, Chile; ,
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Kimura M, Sase T, Higashikawa A, Sato M, Sato T, Tazaki M, Shibukawa Y. High pH-Sensitive TRPA1 Activation in Odontoblasts Regulates Mineralization. J Dent Res 2016; 95:1057-64. [PMID: 27084672 DOI: 10.1177/0022034516644702] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Calcium hydroxide and mineral trioxide aggregate are widely used for indirect and direct pulp capping and root canal filling. Their dissociation into Ca(2+) and OH(-) in dental pulp creates an alkaline environment, which activates reparative/reactionary dentinogenesis. However, the mechanisms by which odontoblasts detect the pH of the extracellular environment remain unclear. We examined the alkali-sensitive intracellular Ca(2+) signaling pathway in rat odontoblasts. In the presence or absence of extracellular Ca(2+), application of alkaline solution increased intracellular Ca(2+) concentration, or [Ca(2+)]i Alkaline solution-induced [Ca(2+)]i increases depended on extracellular pH (8.5 to 10.5) in both the absence and the presence of extracellular Ca(2+) The amplitude was smaller in the absence than in the presence of extracellular Ca(2+) Each increase in [Ca(2+)]i, activated by pH 7.5, 8.5, or 9.5, depended on extracellular Ca(2+) concentration; the equilibrium binding constant for extracellular Ca(2+) concentration decreased as extracellular pH increased (1.04 mM at pH 7.5 to 0.11 mM at pH 9.5). Repeated applications of alkaline solution did not have a desensitizing effect on alkali-induced [Ca(2+)]i increases and inward currents. In the presence of extracellular Ca(2+), alkaline solution-induced [Ca(2+)]i increases were suppressed by application of an antagonist of transient receptor potential ankyrin subfamily member 1 (TRPA1) channels. Ca(2+) exclusion efficiency during alkaline solution-induced [Ca(2+)]i increases was reduced by a Na(+)-Ca(2+) exchanger antagonist. Alizarin red and von Kossa staining revealed increased mineralization levels under repeated high pH stimulation, whereas the TRPA1 antagonist strongly reduced this effect. These findings indicate that alkaline stimuli-such as the alkaline environment inside dental pulp treated with calcium hydroxide or mineral trioxide aggregate-activate Ca(2+) mobilization via Ca(2+) influx mediated by TRPA1 channels and intracellular Ca(2+) release in odontoblasts. High pH-sensing mechanisms in odontoblasts are important for activating dentinogenesis induced by an alkaline environment.
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Affiliation(s)
- M Kimura
- Department of Physiology, Tokyo Dental College, Tokyo, Japan
| | - T Sase
- Department of Crown and Bridge Prosthodontics, Tokyo Dental College, Tokyo, Japan
| | - A Higashikawa
- Department of Physiology, Tokyo Dental College, Tokyo, Japan
| | - M Sato
- Department of Physiology, Tokyo Dental College, Tokyo, Japan
| | - T Sato
- Department of Crown and Bridge Prosthodontics, Tokyo Dental College, Tokyo, Japan
| | - M Tazaki
- Department of Physiology, Tokyo Dental College, Tokyo, Japan
| | - Y Shibukawa
- Department of Physiology, Tokyo Dental College, Tokyo, Japan
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35
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Zierler S, Sumoza-Toledo A, Suzuki S, Dúill FÓ, Ryazanova LV, Penner R, Ryazanov AG, Fleig A. TRPM7 kinase activity regulates murine mast cell degranulation. J Physiol 2016; 594:2957-70. [PMID: 26660477 DOI: 10.1113/jp271564] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Accepted: 12/10/2015] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The Mg(2+) and Ca(2+) conducting transient receptor potential melastatin 7 (TRPM7) channel-enzyme (chanzyme) has been implicated in immune cell function. Mice heterozygous for a TRPM7 kinase deletion are hyperallergic, while mice with a single point mutation at amino acid 1648, silencing kinase activity, are not. As mast cell mediators trigger allergic reactions, we here determine the function of TRPM7 in mast cell degranulation and histamine release. Our data establish that TRPM7 kinase activity regulates mast cell degranulation and release of histamine independently of TRPM7 channel function. Our findings suggest a regulatory role of TRPM7 kinase activity on intracellular Ca(2+) and extracellular Mg(2+) sensitivity of mast cell degranulation. ABSTRACT Transient receptor potential melastatin 7 (TRPM7) is a divalent ion channel with a C-terminally located α-kinase. Mice heterozygous for a TRPM7 kinase deletion (TRPM7(+/∆K) ) are hypomagnesaemic and hyperallergic. In contrast, mice carrying a single point mutation at amino acid 1648, which silences TRPM7 kinase activity (TRPM7(KR) ), are not hyperallergic and are resistant to systemic magnesium (Mg(2+) ) deprivation. Since allergic reactions are triggered by mast cell-mediated histamine release, we investigated the function of TRPM7 on mast cell degranulation and histamine release using wild-type (TRPM7(+/+) ), TRPM7(+/∆K) and TRPM7(KR) mice. We found that degranulation and histamine release proceeded independently of TRPM7 channel function. Furthermore, extracellular Mg(2+) assured unperturbed IgE-DNP-dependent exocytosis, independently of TRPM7. However, impairment of TRPM7 kinase function suppressed IgE-DNP-dependent exocytosis, slowed the cellular degranulation rate, and diminished the sensitivity to intracellular calcium (Ca(2+) ) in G protein-induced exocytosis. In addition, G protein-coupled receptor (GPCR) stimulation revealed strong suppression of histamine release, whereas removal of extracellular Mg(2+) caused the phenotype to revert. We conclude that the TRPM7 kinase activity regulates murine mast cell degranulation by changing its sensitivity to intracellular Ca(2+) and affecting granular mobility and/or histamine contents.
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Affiliation(s)
- Susanna Zierler
- Center for Biomedical Research, The Queen's Medical Center and University of Hawaii John A. Burns School of Medicine and Cancer Center, Honolulu, HI, 96813, USA.,Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, 80336, Munich, Germany
| | - Adriana Sumoza-Toledo
- Center for Biomedical Research, The Queen's Medical Center and University of Hawaii John A. Burns School of Medicine and Cancer Center, Honolulu, HI, 96813, USA.,Instituto de Investigaciones Médico-Biológicas, Universidad Veracruzana, Colonia Centro CP 91700, Veracruz, Mexico
| | - Sayuri Suzuki
- Center for Biomedical Research, The Queen's Medical Center and University of Hawaii John A. Burns School of Medicine and Cancer Center, Honolulu, HI, 96813, USA
| | - Fionán Ó Dúill
- Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, 80336, Munich, Germany
| | - Lillia V Ryazanova
- Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ, 08854, USA
| | - Reinhold Penner
- Center for Biomedical Research, The Queen's Medical Center and University of Hawaii John A. Burns School of Medicine and Cancer Center, Honolulu, HI, 96813, USA
| | - Alexey G Ryazanov
- Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ, 08854, USA
| | - Andrea Fleig
- Center for Biomedical Research, The Queen's Medical Center and University of Hawaii John A. Burns School of Medicine and Cancer Center, Honolulu, HI, 96813, USA
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Schäfer S, Ferioli S, Hofmann T, Zierler S, Gudermann T, Chubanov V. Mibefradil represents a new class of benzimidazole TRPM7 channel agonists. Pflugers Arch 2015; 468:623-34. [PMID: 26669310 DOI: 10.1007/s00424-015-1772-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 12/02/2015] [Accepted: 12/04/2015] [Indexed: 01/16/2023]
Abstract
Transient receptor potential cation channel, subfamily M, member 7 (TRPM7) is a bi-functional protein comprising an ion channel moiety covalently linked to a protein kinase domain. Currently, the prevailing view is that a decrease in the cytosolic Mg(2+) concentration leads to activation of divalent cation-selective TRPM7 currents. TRPM7 plays a role in immune responses, hypotension, tissue fibrosis, and tumor progression and, therefore, represents a new promising therapeutic target. Because of the dearth of pharmacological tools, our mechanistic understanding of the role of TRPM7 in physiology and pathophysiology still lags behind. Therefore, we have recently carried out a high throughput screen for small-molecule activators of TRPM7. We have characterized the phenanthrene naltriben as a first stimulatory agonist of the TRPM7 channel. Surprisingly, the effect of naltriben on TRPM7 was found to be unaffected by the physiological levels of cytosolic Mg(2+). Here, we demonstrate that mibefradil and NNC 50-0396, two benzimidazole relatives of the TRPM7 inhibitor NS8593, are positive modulators of TRPM7. Using Ca(2+) imaging and the patch-clamp technique, we show that mibefradil activates TRPM7-mediated Ca(2+) entry and whole-cell currents. The response to mibefradil was fast, reversible, and reproducible. In contrast to naltriben, mibefradil efficiently activates TRPM7 currents only at physiological intracellular Mg(2+) concentrations, and its stimulatory effect was fully abrogated by high internal Mg(2+) levels. Consequently, a TRPM7 variant harboring a gain-of-function mutation was insensitive to further mibefradil activation. Finally, we observed that the effect of mibefradil was selective for TRPM7 when various TRP channels were tested. Taken together, mibefradil acts as a Mg(2+)-regulated agonist of the TRPM7 channel and, hence, uncovers a new class of TRPM7 agonists.
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Affiliation(s)
- Sebastian Schäfer
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Silvia Ferioli
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Thomas Hofmann
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Susanna Zierler
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Thomas Gudermann
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Goethestrasse 33, 80336, Munich, Germany
- Comprehensive Pneumology Center Munich (CPC-M), German Center for Lung Research, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), Munich Heart Alliance, Munich, Germany
| | - Vladimir Chubanov
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Goethestrasse 33, 80336, Munich, Germany.
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Charge Shielding of PIP2 by Cations Regulates Enzyme Activity of Phospholipase C. PLoS One 2015; 10:e0144432. [PMID: 26658739 PMCID: PMC4676720 DOI: 10.1371/journal.pone.0144432] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 11/18/2015] [Indexed: 11/19/2022] Open
Abstract
Hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) of the plasma membrane by phospholipase C (PLC) generates two critical second messengers, inositol-1,4,5-trisphosphate and diacylglycerol. For the enzymatic reaction, PIP2 binds to positively charged amino acids in the pleckstrin homology domain of PLC. Here we tested the hypothesis that positively charged divalent and multivalent cations accumulate around the negatively charged PIP2, a process called electrostatic charge shielding, and therefore inhibit electrostatic PIP2-PLC interaction. This charge shielding of PIP2 was measured quantitatively with an in vitro enzyme assay using WH-15, a PIP2 analog, and various recombinant PLC proteins (β1, γ1, and δ1). Reduction of PLC activity by divalent cations, polyamines, and neomycin was well described by a theoretical model considering accumulation of cations around PIP2 via their electrostatic interaction and chemical binding. Finally, the charge shielding of PIP2 was also observed in live cells. Perfusion of the cations into cells via patch clamp pipette reduced PIP2 hydrolysis by PLC as triggered by M1 muscarinic receptors with a potency order of Mg2+ < spermine4+ < neomycin6+. Accumulation of divalent cations into cells through divalent-permeable TRPM7 channel had the same effect. Altogether our results suggest that Mg2+ and polyamines modulate the activity of PLCs by controlling the amount of free PIP2 available for the enzymes and that highly charged biomolecules can be inactivated by counterions electrostatically.
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38
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Tsujikawa H, Yu AS, Xie J, Yue Z, Yang W, He Y, Yue L. Identification of key amino acid residues responsible for internal and external pH sensitivity of Orai1/STIM1 channels. Sci Rep 2015; 5:16747. [PMID: 26576490 PMCID: PMC4649748 DOI: 10.1038/srep16747] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Accepted: 10/20/2015] [Indexed: 12/27/2022] Open
Abstract
Changes of intracellular and extracellular pH are involved in a variety of physiological and pathological processes, in which regulation of the Ca2+ release activated Ca2+ channel (ICRAC) by pH has been implicated. Ca2+ entry mediated by ICRAC has been shown to be regulated by acidic or alkaline pH. Whereas several amino acid residues have been shown to contribute to extracellular pH (pHo) sensitivity, the molecular mechanism for intracellular pH (pHi) sensitivity of Orai1/STIM1 is not fully understood. By investigating a series of mutations, we find that the previously identified residue E106 is responsible for pHo sensitivity when Ca2+ is the charge carrier. Unexpectedly, we identify that the residue E190 is responsible for pHo sensitivity when Na+ is the charge carrier. Furthermore, the intracellular mutant H155F markedly diminishes the response to acidic and alkaline pHi, suggesting that H155 is responsible for pHi sensitivity of Orai1/STIM1. Our results indicate that, whereas H155 is the intracellular pH sensor of Orai1/STIM1, the molecular mechanism of external pH sensitivity varies depending on the permeant cations. As changes of pH are involved in various physiological/pathological functions, Orai/STIM channels may be an important mediator for various physiological and pathological processes associated with acidosis and alkalinization.
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Affiliation(s)
- Hiroto Tsujikawa
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
| | - Albert S Yu
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
| | - Jia Xie
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
| | - Zhichao Yue
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
| | - Wenzhong Yang
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
| | - Yanlin He
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
| | - Lixia Yue
- Calhoun Cardiology Center, Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
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Abstract
Store-operated calcium channels (SOCs) are a major pathway for calcium signaling in virtually all metozoan cells and serve a wide variety of functions ranging from gene expression, motility, and secretion to tissue and organ development and the immune response. SOCs are activated by the depletion of Ca(2+) from the endoplasmic reticulum (ER), triggered physiologically through stimulation of a diverse set of surface receptors. Over 15 years after the first characterization of SOCs through electrophysiology, the identification of the STIM proteins as ER Ca(2+) sensors and the Orai proteins as store-operated channels has enabled rapid progress in understanding the unique mechanism of store-operate calcium entry (SOCE). Depletion of Ca(2+) from the ER causes STIM to accumulate at ER-plasma membrane (PM) junctions where it traps and activates Orai channels diffusing in the closely apposed PM. Mutagenesis studies combined with recent structural insights about STIM and Orai proteins are now beginning to reveal the molecular underpinnings of these choreographic events. This review describes the major experimental advances underlying our current understanding of how ER Ca(2+) depletion is coupled to the activation of SOCs. Particular emphasis is placed on the molecular mechanisms of STIM and Orai activation, Orai channel properties, modulation of STIM and Orai function, pharmacological inhibitors of SOCE, and the functions of STIM and Orai in physiology and disease.
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Affiliation(s)
- Murali Prakriya
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; and Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California
| | - Richard S Lewis
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois; and Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, California
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PKD2L1/PKD1L3 channel complex with an alkali-activated mechanism and calcium-dependent inactivation. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2015; 44:483-92. [PMID: 26066678 DOI: 10.1007/s00249-015-1040-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Revised: 04/20/2015] [Accepted: 05/07/2015] [Indexed: 10/23/2022]
Abstract
Polycystic kidney disease-like (PKDL) genes that are expressed in sour taste cells have been proposed to be involved in the transduction of sourness by producing off-responses, which shows a large inward current after withdrawing the acid stimuli. However, the underlying mechanisms of off-responses are still unclear. Here, we demonstrate that an alkali-activated mechanism is responsible for eliciting off-responses, as evidenced by both experimental and theoretical analyses. In addition, we showed that the decaying phase of offset responses in PKD2L1/PKD1L3 channels was substantially accelerated by extracellular Ca(2+).
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Kazama I. Physiological significance of delayed rectifier K(+) channels (Kv1.3) expressed in T lymphocytes and their pathological significance in chronic kidney disease. J Physiol Sci 2015; 65:25-35. [PMID: 25096892 PMCID: PMC10717717 DOI: 10.1007/s12576-014-0331-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/14/2014] [Indexed: 11/24/2022]
Abstract
T lymphocytes predominantly express delayed rectifier K(+) channels (Kv1.3) in their plasma membranes. More than 30 years ago, patch-clamp studies revealed that the channels play crucial roles in facilitating the calcium influx necessary to trigger lymphocyte activation and proliferation. In addition to selective channel inhibitors that have been developed, we recently showed physiological evidence that drugs such as nonsteroidal anti-inflammatory drugs, antibiotics, and anti-hypertensives effectively suppress the channel currents in lymphocytes, and thus exert immunosuppressive effects. Using experimental animal models, previous studies revealed the pathological relevance between the expression of ion channels and the progression of renal diseases. As an extension, we recently demonstrated that the overexpression of lymphocyte Kv1.3 channels contributed to the progression of chronic kidney disease (CKD) by promoting cellular proliferation and interstitial fibrosis. Together with our in-vitro results, the studies indicated the therapeutic potency of Kv1.3-channel inhibitors in the treatment or the prevention of CKD.
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Affiliation(s)
- Itsuro Kazama
- Department of Physiology I, Tohoku University Graduate School of Medicine, Seiryo-cho, Aoba-ku, Sendai, Miyagi, Japan,
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42
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Natural and Synthetic Modulators of the TRPM7 Channel. Cells 2014; 3:1089-101. [PMID: 25437439 PMCID: PMC4276914 DOI: 10.3390/cells3041089] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 11/19/2014] [Accepted: 11/20/2014] [Indexed: 11/16/2022] Open
Abstract
Transient receptor potential cation channel subfamily M member 7 (TRPM7) is a bi-functional protein comprising a TRP ion channel segment linked to an α-type protein kinase domain. Genetic inactivation of TRPM7 revealed its central role in magnesium metabolism, cell motility, proliferation and differentiation. TRPM7 is associated with anoxic neuronal death, cardiac fibrosis and tumor progression highlighting TRPM7 as a new drug target. Recently, several laboratories have independently identified pharmacological compounds inhibiting or activating the TRPM7 channel. The recently found TRPM7 modulators were used as new experimental tools to unravel cellular functions of the TRPM7 channel. Here, we provide a concise overview of this emerging field.
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43
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Yamaguchi S, Tanimoto A, Otsuguro KI, Hibino H, Ito S. Negatively charged amino acids near and in transient receptor potential (TRP) domain of TRPM4 channel are one determinant of its Ca2+ sensitivity. J Biol Chem 2014; 289:35265-82. [PMID: 25378404 DOI: 10.1074/jbc.m114.606087] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transient receptor potential (TRP) channel melastatin subfamily member 4 (TRPM4) is a broadly expressed nonselective monovalent cation channel. TRPM4 is activated by membrane depolarization and intracellular Ca(2+), which is essential for the activation. The Ca(2+) sensitivity is known to be regulated by calmodulin and membrane phosphoinositides, such as phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). Although these regulators must play important roles in controlling TRPM4 activity, mutation analyses of the calmodulin-binding sites have suggested that Ca(2+) binds to TRPM4 directly. However, the intrinsic binding sites in TRPM4 remain to be elucidated. Here, by using patch clamp and molecular biological techniques, we show that there are at least two functionally different divalent cation-binding sites, and the negatively charged amino acids near and in the TRP domain in the C-terminal tail of TRPM4 (Asp-1049 and Glu-1062 of rat TRPM4) are required for maintaining the normal Ca(2+) sensitivity of one of the binding sites. Applications of Co(2+), Mn(2+), or Ni(2+) to the cytosolic side potentiated TRPM4 currents, increased the Ca(2+) sensitivity, but were unable to evoke TRPM4 currents without Ca(2+). Mutations of the acidic amino acids near and in the TRP domain, which are conserved in TRPM2, TRPM5, and TRPM8, deteriorated the Ca(2+) sensitivity in the presence of Co(2+) or PI(4,5)P2 but hardly affected the sensitivity to Co(2+) and PI(4,5)P2. These results suggest a novel role of the TRP domain in TRPM4 as a site responsible for maintaining the normal Ca(2+) sensitivity. These findings provide more insights into the molecular mechanisms of the regulation of TRPM4 by Ca(2+).
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Affiliation(s)
- Soichiro Yamaguchi
- From the Laboratory of Pharmacology, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, 060-0818 and the Department of Molecular Physiology, Niigata University School of Medicine, Niigata 951-8510, Japan
| | - Akira Tanimoto
- From the Laboratory of Pharmacology, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, 060-0818 and
| | - Ken-ichi Otsuguro
- From the Laboratory of Pharmacology, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, 060-0818 and
| | - Hiroshi Hibino
- the Department of Molecular Physiology, Niigata University School of Medicine, Niigata 951-8510, Japan
| | - Shigeo Ito
- From the Laboratory of Pharmacology, Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Hokkaido, 060-0818 and
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44
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Tashiro M, Inoue H, Konishi M. Physiological pathway of magnesium influx in rat ventricular myocytes. Biophys J 2014; 107:2049-58. [PMID: 25418090 PMCID: PMC4223180 DOI: 10.1016/j.bpj.2014.09.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/03/2014] [Accepted: 09/16/2014] [Indexed: 11/16/2022] Open
Abstract
Cytoplasmic free Mg(2+) concentration ([Mg(2+)]i) was measured in rat ventricular myocytes with a fluorescent indicator furaptra (mag-fura-2) introduced by AM-loading. By incubation of the cells in a high-K(+) (Ca(2+)- and Mg(2+)-free) solution, [Mg(2+)]i decreased from ? 0.9 mM to 0.2 to 0.5 mM. The lowered [Mg(2+)]i was recovered by perfusion with Ca(2+)-free Tyrode's solution containing 1 mM Mg(2+). The time course of the [Mg(2+)]i recovery was fitted by a single exponential function, and the first derivative at time 0 was analyzed as being proportional to the initial Mg(2+) influx rate. The Mg(2+) influx rate was inversely related to [Mg(2+)]i, being higher at low [Mg(2+)]i. The Mg(2+) influx rate was augmented by the high extracellular Mg(2+) concentration (5 mM), whereas it was greatly reduced by cell membrane depolarization caused by high K(+). Known inhibitors of TRPM7 channels, 2-aminoethoxydiphenyl borate (2-APB), NS8593, and spermine reduced the Mg(2+) influx rate with half inhibitory concentrations (IC50) of, respectively, 17 ?M, 2.0 ?M, and 22 ?M. We also studied Ni(2+) influx by fluorescence quenching of intracellular furaptra by Ni(2+). The Ni(2+) influx was activated by lowering intra- and extracellular Mg(2+) concentrations, and it was inhibited by 2-APB and NS8593 with IC50 values comparable with those for the Mg(2+) influx. Intracellular alkalization (caused by pulse application of NH4Cl) enhanced, whereas intracellular acidification (induced after the removal of NH4Cl) slowed the Mg(2+) influx. Under the whole-cell patch-clamp configuration, the removal of intracellular and extracellular divalent cations induced large inward and outward currents, MIC (Mg-inhibited cation) currents or IMIC, carried by monovalent cations likely via TRPM7 channels. IMIC measured at -120 mV was diminished to ? 50% by 100 ?M 2-APB or 10 ?M NS8593. These results suggest that TRPM7/MIC channels serve as a major physiological pathway of Mg(2+) influx in rat ventricular myocytes.
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Affiliation(s)
- Michiko Tashiro
- Department of Physiology, Tokyo Medical University, Tokyo 160-8402, Japan.
| | - Hana Inoue
- Department of Physiology, Tokyo Medical University, Tokyo 160-8402, Japan
| | - Masato Konishi
- Department of Physiology, Tokyo Medical University, Tokyo 160-8402, Japan
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45
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Visser D, Middelbeek J, van Leeuwen FN, Jalink K. Function and regulation of the channel-kinase TRPM7 in health and disease. Eur J Cell Biol 2014; 93:455-65. [DOI: 10.1016/j.ejcb.2014.07.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 06/24/2014] [Accepted: 07/01/2014] [Indexed: 11/30/2022] Open
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46
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Yee NS, Kazi AA, Yee RK. Cellular and Developmental Biology of TRPM7 Channel-Kinase: Implicated Roles in Cancer. Cells 2014; 3:751-77. [PMID: 25079291 PMCID: PMC4197629 DOI: 10.3390/cells3030751] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 07/15/2014] [Accepted: 07/15/2014] [Indexed: 12/29/2022] Open
Abstract
The transient receptor potential melastatin-subfamily member 7 (TRPM7) is a ubiquitously expressed cation-permeable ion channel with intrinsic kinase activity that plays important roles in various physiological functions. Biochemical and electrophysiological studies, in combination with molecular analyses of TRPM7, have generated insights into its functions as a cellular sensor and transducer of physicochemical stimuli. Accumulating evidence indicates that TRPM7 channel-kinase is essential for cellular processes, such as proliferation, survival, differentiation, growth, and migration. Experimental studies in model organisms, such as zebrafish, mouse, and frog, have begun to elucidate the pleiotropic roles of TRPM7 during embryonic development from gastrulation to organogenesis. Aberrant expression and/or activity of the TRPM7 channel-kinase have been implicated in human diseases including a variety of cancer. Studying the functional roles of TRPM7 and the underlying mechanisms in normal cells and developmental processes is expected to help understand how TRPM7 channel-kinase contributes to pathogenesis, such as malignant neoplasia. On the other hand, studies of TRPM7 in diseases, particularly cancer, will help shed new light in the normal functions of TRPM7 under physiological conditions. In this article, we will provide an updated review of the structural features and biological functions of TRPM7, present a summary of current knowledge of its roles in development and cancer, and discuss the potential of TRPM7 as a clinical biomarker and therapeutic target in malignant diseases.
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Affiliation(s)
- Nelson S Yee
- Division of Hematology-Oncology, Department of Medicine, Penn State College of Medicine, Program of Experimental Therapeutics, Penn State Hershey Cancer Institute, Penn State Milton S, Hershey Medical Center, Pennsylvania State University, Hershey, PA 17033, USA.
| | - Abid A Kazi
- Division of Hematology-Oncology, Department of Medicine, Penn State College of Medicine, Program of Experimental Therapeutics, Penn State Hershey Cancer Institute, Penn State Milton S, Hershey Medical Center, Pennsylvania State University, Hershey, PA 17033, USA.
| | - Rosemary K Yee
- Schreyer Honors College, Pennsylvania State University, University Park, PA 16802, USA; Penn State Harrisburg School of Humanities, Pennsylvania State University, Middletown, PA 17057, USA.
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47
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Zhou W, Guo S, Xiong Z, Liu M. Oncogenic role and therapeutic target of transient receptor potential melastatin 7 channel in malignancy. Expert Opin Ther Targets 2014; 18:1177-96. [DOI: 10.1517/14728222.2014.940894] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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48
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Inactivation of TRPM7 kinase activity does not impair its channel function in mice. Sci Rep 2014; 4:5718. [PMID: 25030553 PMCID: PMC4101474 DOI: 10.1038/srep05718] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 06/23/2014] [Indexed: 11/30/2022] Open
Abstract
Transient receptor potential (TRP) family channels are involved in sensory pathways and respond to various environmental stimuli. Among the members of this family, TRPM7 is a unique fusion of an ion channel and a C-terminus kinase domain that is highly expressed in immune cells. TRPM7 serves as a key molecule governing cellular Mg2+ homeostasis in mammals since its channel pore is permeable to Mg2+ ions and can act as a Mg2+ influx pathway. However, mechanistic links between its kinase activity and channel function have remained uncertain. In this study, we generated kinase inactive knock-in mutant mice by mutagenesis of a key lysine residue involved in Mg2+-ATP binding. These mutant mice were normal in development and general locomotor activity. In peritoneal macrophages isolated from adult animals the basal activity of TRPM7 channels prior to cytoplasmic Mg2+ depletion was significantly potentiated, while maximal current densities measured after Mg2+ depletion were unchanged in the absence of detectable kinase function. Serum total Ca2+ and Mg2+ levels were not significantly altered in kinase-inactive mutant mice. Our findings suggest that abolishing TRPM7 kinase activity does not impair its channel activity and kinase activity is not essential for regulation of mammalian Mg2+ homeostasis.
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49
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Inoue H, Murayama T, Tashiro M, Sakurai T, Konishi M. Mg(2+)- and ATP-dependent inhibition of transient receptor potential melastatin 7 by oxidative stress. Free Radic Biol Med 2014; 72:257-66. [PMID: 24747489 DOI: 10.1016/j.freeradbiomed.2014.04.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 04/09/2014] [Accepted: 04/10/2014] [Indexed: 11/25/2022]
Abstract
Transient receptor potential melastatin 7 (TRPM7) is a Ca(2+)- and Mg(2+)-permeable nonselective cation channel that contains a unique carboxyl-terminal serine/threonine protein kinase domain. It has been reported that reactive oxygen species associated with hypoxia or ischemia activate TRPM7 current and then induce Ca(2+) overload resulting in neuronal cell death in the brain. In this study, we aimed to investigate the molecular mechanisms of TRPM7 regulation by hydrogen peroxide (H2O2) using murine TRPM7 expressed in HEK293 cells. Using the whole-cell patch-clamp technique, it was revealed that the TRPM7 current was inhibited, not activated, by the application of H2O2 to the extracellular solution. This inhibition was not reversed after washout or treatment with dithiothreitol, suggesting irreversible oxidation of TRPM7 or its regulatory factors by H2O2 under whole-cell recording. Application of an electrophile, N-methylmaleimide (NMM), which covalently modifies cysteine residues in proteins, also inhibited TRPM7 current irreversibly. The effects of H2O2 and NMM were dependent on free [Mg(2+)]i; the inhibition was stronger when cells were perfused with higher free [Mg(2+)]i solutions via pipette. In addition, TRPM7 current was not inhibited by H2O2 when millimolar ATP was included in the intracellular solution, even in the presence of substantial free [Mg(2+)]i, which is sufficient for TRPM7 inhibition by H2O2 in the absence of ATP. Moreover, a kinase-deficient mutant of TRPM7 (K1645R) was similarly inhibited by H2O2 just like the wild-type TRPM7 in a [Mg(2+)]i- and [ATP]i-dependent manner, indicating no involvement of the kinase activity of TRPM7. Thus, these data suggest that oxidative stress inhibits TRPM7 current under pathological conditions that accompany intracellular ATP depletion and free [Mg(2+)]i elevation.
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Affiliation(s)
- Hana Inoue
- Department of Physiology, Tokyo Medical University, 160-8402 Tokyo, Japan.
| | - Takashi Murayama
- Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Michiko Tashiro
- Department of Physiology, Tokyo Medical University, 160-8402 Tokyo, Japan
| | - Takashi Sakurai
- Cellular and Molecular Pharmacology, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Masato Konishi
- Department of Physiology, Tokyo Medical University, 160-8402 Tokyo, Japan
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50
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Hofmann T, Schäfer S, Linseisen M, Sytik L, Gudermann T, Chubanov V. Activation of TRPM7 channels by small molecules under physiological conditions. Pflugers Arch 2014; 466:2177-89. [PMID: 24633576 DOI: 10.1007/s00424-014-1488-0] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 02/17/2014] [Accepted: 02/18/2014] [Indexed: 01/07/2023]
Abstract
Transient receptor potential cation channel, subfamily M, member 7 (TRPM7) is a cation channel covalently linked to a protein kinase domain. TRPM7 is ubiquitously expressed and regulates key cellular processes such as Mg(2+) homeostasis, motility, and proliferation. TRPM7 is involved in anoxic neuronal death, cardiac fibrosis, and tumor growth. The goal of this work was to identify small molecule activators of the TRPM7 channel and investigate their mechanism of action. We used an aequorin bioluminescence-based assay to screen for activators of the TRPM7 channel. Valid candidates were further characterized using patch clamp electrophysiology. We identified 20 drug-like compounds with various structural backbones that can activate the TRPM7 channel. Among them, the δ opioid antagonist naltriben was studied in greater detail. Naltriben's action was selective among the TRP channels tested. Naltriben activates TRPM7 currents without prior depletion of intracellular Mg(2+) even under conditions of low PIP2. Moreover, naltriben interfered with the effect of the TRPM7 inhibitor NS8593. Finally, our experiments with TRPM7 variants carrying mutations in the pore, TRP, and kinase domains indicate that the site of TRPM7 activation by this small-molecule ligand is most likely located in or near the TRP domain. In conclusion, we identified the first organic small-molecule activators of TRPM7 channels, thus providing new experimental tools to study TRPM7 function in native cellular environments.
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Affiliation(s)
- T Hofmann
- Philipps-Universität Marburg, Klinik für Innere Medizin/Nephrologie, Baldingerstraße 1, 35043, Marburg, Germany,
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