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Schreiber R, Ousingsawat J, Kunzelmann K. The anoctamins: Structure and function. Cell Calcium 2024; 120:102885. [PMID: 38642428 DOI: 10.1016/j.ceca.2024.102885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/03/2024] [Accepted: 04/04/2024] [Indexed: 04/22/2024]
Abstract
When activated by increase in intracellular Ca2+, anoctamins (TMEM16 proteins) operate as phospholipid scramblases and as ion channels. Anoctamin 1 (ANO1) is the Ca2+-activated epithelial anion-selective channel that is coexpressed together with the abundant scramblase ANO6 and additional intracellular anoctamins. In salivary and pancreatic glands, ANO1 is tightly packed in the apical membrane and secretes Cl-. Epithelia of airways and gut use cystic fibrosis transmembrane conductance regulator (CFTR) as an apical Cl- exit pathway while ANO1 supports Cl- secretion mainly by facilitating activation of luminal CFTR and basolateral K+ channels. Under healthy conditions ANO1 modulates intracellular Ca2+ signals by tethering the endoplasmic reticulum, and except of glands its direct secretory contribution as Cl- channel might be small, compared to CFTR. In the kidneys ANO1 supports proximal tubular acid secretion and protein reabsorption and probably helps to excrete HCO3-in the collecting duct epithelium. However, under pathological conditions as in polycystic kidney disease, ANO1 is strongly upregulated and may cause enhanced proliferation and cyst growth. Under pathological condition, ANO1 and ANO6 are upregulated and operate as secretory channel/phospholipid scramblases, partly by supporting Ca2+-dependent processes. Much less is known about the role of other epithelial anoctamins whose potential functions are discussed in this review.
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Affiliation(s)
- Rainer Schreiber
- Physiological Institute, University of Regensburg, University street 31, D-93053 Regensburg, Germany
| | - Jiraporn Ousingsawat
- Physiological Institute, University of Regensburg, University street 31, D-93053 Regensburg, Germany
| | - Karl Kunzelmann
- Physiological Institute, University of Regensburg, University street 31, D-93053 Regensburg, Germany.
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2
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Dibattista M, Pifferi S, Hernandez-Clavijo A, Menini A. The physiological roles of anoctamin2/TMEM16B and anoctamin1/TMEM16A in chemical senses. Cell Calcium 2024; 120:102889. [PMID: 38677213 DOI: 10.1016/j.ceca.2024.102889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/11/2024] [Accepted: 04/17/2024] [Indexed: 04/29/2024]
Abstract
Chemical senses allow animals to detect and discriminate a vast array of molecules. The olfactory system is responsible of the detection of small volatile molecules, while water dissolved molecules are detected by taste buds in the oral cavity. Moreover, many animals respond to signaling molecules such as pheromones and other semiochemicals through the vomeronasal organ. The peripheral organs dedicated to chemical detection convert chemical signals into perceivable information through the employment of diverse receptor types and the activation of multiple ion channels. Two ion channels, TMEM16B, also known as anoctamin2 (ANO2) and TMEM16A, or anoctamin1 (ANO1), encoding for Ca2+-activated Cl¯ channels, have been recently described playing critical roles in various cell types. This review aims to discuss the main properties of TMEM16A and TMEM16B-mediated currents and their physiological roles in chemical senses. In olfactory sensory neurons, TMEM16B contributes to amplify the odorant response, to modulate firing, response kinetics and adaptation. TMEM16A and TMEM16B shape the pattern of action potentials in vomeronasal sensory neurons increasing the interspike interval. In type I taste bud cells, TMEM16A is activated during paracrine signaling mediated by ATP. This review aims to shed light on the regulation of diverse signaling mechanisms and neuronal excitability mediated by Ca-activated Cl¯ channels, hinting at potential new roles for TMEM16A and TMEM16B in the chemical senses.
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Affiliation(s)
- Michele Dibattista
- Department of Translational Biomedicine and Neuroscience, University of Bari A. Moro, 70121 Bari, Italy
| | - Simone Pifferi
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60126 Ancona, Italy.
| | - Andres Hernandez-Clavijo
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, 52074 Aachen, Germany
| | - Anna Menini
- Neurobiology Group, SISSA, Scuola Internazionale Superiore di Studi Avanzati, 34136 Trieste, Italy.
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Arreola J, Pérez-Cornejo P, Segura-Covarrubias G, Corral-Fernández N, León-Aparicio D, Guzmán-Hernández ML. Function and Regulation of the Calcium-Activated Chloride Channel Anoctamin 1 (TMEM16A). Handb Exp Pharmacol 2024; 283:101-151. [PMID: 35768554 DOI: 10.1007/164_2022_592] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Various human tissues express the calcium-activated chloride channel Anoctamin 1 (ANO1), also known as TMEM16A. ANO1 allows the passive chloride flux that controls different physiological functions ranging from muscle contraction, fluid and hormone secretion, gastrointestinal motility, and electrical excitability. Overexpression of ANO1 is associated with pathological conditions such as hypertension and cancer. The molecular cloning of ANO1 has led to a surge in structural, functional, and physiological studies of the channel in several tissues. ANO1 is a homodimer channel harboring two pores - one in each monomer - that work independently. Each pore is activated by voltage-dependent binding of two intracellular calcium ions to a high-affinity-binding site. In addition, the binding of phosphatidylinositol 4,5-bisphosphate to sites scattered throughout the cytosolic side of the protein aids the calcium activation process. Furthermore, many pharmacological studies have established ANO1 as a target of promising compounds that could treat several illnesses. This chapter describes our current understanding of the physiological roles of ANO1 and its regulation under physiological conditions as well as new pharmacological compounds with potential therapeutic applications.
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Affiliation(s)
- Jorge Arreola
- Physics Institute, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico.
| | - Patricia Pérez-Cornejo
- Department of Physiology and Biophysics, School of Medicine of Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
| | - Guadalupe Segura-Covarrubias
- Physics Institute, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA
| | - Nancy Corral-Fernández
- Department of Physiology and Biophysics, School of Medicine of Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
| | - Daniel León-Aparicio
- Physics Institute, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico
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Inagaki S, Suzuki Y, Kawasaki K, Kondo R, Imaizumi Y, Yamamura H. Mitofusin 1 and 2 differentially regulate mitochondrial function underlying Ca 2+ signaling and proliferation in rat aortic smooth muscle cells. Biochem Biophys Res Commun 2023; 645:137-146. [PMID: 36689810 DOI: 10.1016/j.bbrc.2023.01.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 01/14/2023] [Indexed: 01/18/2023]
Abstract
Mitochondria play a substantial role in cytosolic Ca2+ buffering and energy metabolism. We recently demonstrated that mitofusin 2 (Mfn2) regulated Ca2+ signaling by tethering mitochondria and sarcoplasmic reticulum (SR), and thus, facilitated mitochondrial function and the proliferation of vascular smooth muscle cells (VSMCs). However, the physiological role of mitofusin 1 (Mfn1) on Ca2+ signaling and mitochondrial function remains unclear. Herein, the roles of Mfn1 and Mfn2 in mitochondrial function underlying Ca2+ signaling, ATP production, and cell proliferation were examined in rat aortic smooth muscle A10 cells. Following an arginine vasopressin-induced increase in cytosolic Ca2+ concentration ([Ca2+]cyt), Mfn2 siRNA (siMfn2) reduced cytosolic Ca2+ removal and mitochondrial Ca2+ uptake. However, Mfn1 siRNA (siMfn1) attenuated mitochondrial Ca2+ uptake, facilitated Ca2+ removal from mitochondria, and resulted in increased [Ca2+]cyt, which was mediated by the downregulation of mitochondrial Ca2+ uniporter (MCU) expression and the upregulation of mitochondrial Na+/Ca2+ exchanger (NCLX) expression. Furthermore, siMfn1 increased the mitochondrial membrane potential, ATP production by adenine nucleotide translocase (ANT), and cell proliferation, whereas siMfn2 exhibited the opposite responses. In conclusion, Mfn1 modulates the expressions of MCU, NCLX, and ANT, and Mfn2 tethers mitochondria to SR, which demonstrates their different mitochondrial functions for Ca2+ signaling, ATP production, and the proliferation of VSMCs.
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Affiliation(s)
- Sou Inagaki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Keisuke Kawasaki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Rubii Kondo
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Yuji Imaizumi
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan.
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Kawata N, Kondo R, Suzuki Y, Yamamura H. Increased TMEM16A-mediated Ca 2+-activated Cl - currents in portal vein smooth muscle cells of caveolin 1-deficient mice. Biol Pharm Bull 2022; 45:1692-1698. [PMID: 35989294 DOI: 10.1248/bpb.b22-00514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ca2+-activated Cl- (ClCa) channels regulate membrane excitability and myogenic tone in vascular smooth muscles. TMEM16A-coding proteins are mainly responsible for functional ClCa channels in vascular smooth muscles, including portal vein smooth muscles (PVSMs). Caveolae are cholesterol-rich and Ω-shaped invaginations on the plasma membrane that structurally contributes to effective and efficient signal transduction. Caveolin 1 (Cav1) accumulates in caveolae to form functional complexes among receptors, ion channels, and kinases. The present study examined the functional roles of Cav1 in the expression and activity of ClCa channels in the portal vein smooth muscle cells (PVSMCs) of wild-type (WT) and Cav1-knockout (KO) mice. Contractile experiments revealed that the amplitude of spontaneous PVSM contractions was larger in Cav1-KO mice than WT mice. Under whole-cell patch-clamp configurations, ClCa currents were markedly inhibited by 1 μM Ani9 (a selective TMEM16A ClCa channel blocker) in WT and Cav1-KO PVSMCs. However, Ani9-sensitive ClCa currents were significantly larger in Cav1-KO PVSMCs than in WT PVSMCs. Expression analyses showed that TMEM16A expression levels were higher in Cav1-KO PVSMs than in WT PVSMs. Therefore, the caveolar structure formed by Cav1 negatively regulates the expression and activity of TMEM16A-mediated ClCa channels in vascular smooth muscle cells.
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Affiliation(s)
- Naoki Kawata
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Rubii Kondo
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
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6
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Ando S, Mizutani H, Muramatsu M, Hagihara Y, Mishima H, Kondo R, Suzuki Y, Imaizumi Y, Yamamura H. Involvement of small-conductance Ca2+-activated K+ (SKCa2) channels in spontaneous Ca2+ oscillations in rat pinealocytes. Biochem Biophys Res Commun 2022; 615:157-162. [DOI: 10.1016/j.bbrc.2022.05.052] [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] [Accepted: 05/14/2022] [Indexed: 11/02/2022]
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Inagaki S, Suzuki Y, Kawasaki K, Kondo R, Imaizumi Y, Yamamura H. Mitofusin 2 positively regulates Ca 2+ signaling by tethering the sarcoplasmic reticulum and mitochondria in rat aortic smooth muscle cells. Am J Physiol Cell Physiol 2022; 323:C295-C305. [PMID: 35704692 DOI: 10.1152/ajpcell.00274.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mitochondria buffer cytosolic Ca2+increases following Ca2+ influx from extracellular spaces and Ca2+ release from intracellular Ca2+ store sites under physiological circumstances. Therefore, close contact of mitochondria with the sarcoplasmic reticulum (SR) is required for maintaining Ca2+ homeostasis. Mitofusin 2 (Mfn2) localizes in both mitochondrial and SR membranes, and is hypothesized to optimize the distance and Ca2+ transfer between these organelles. However, the physiological significance of Mfn2 in vascular smooth muscle cells (VSMCs) is poorly understood. In the present study, the role of Mfn2 in the physical and functional couplings between SR and mitochondria was examined in rat aortic smooth muscle cells (rASMCs) by confocal and electron microscope imaging. When Mfn2 was knocked-down using siRNA in rASMCs, the mean distance between these organelles was extended from 16.2 to 21.6 nm. The increase in the cytosolic Ca2+ concentration ([Ca2+]cyt) induced by 100 nM arginine vasopressin (AVP) was not affected by Mfn2 siRNA knockdown, whereas cytosolic Ca2+ removal was slower after Mfn2 knockdown. Following the AVP-induced [Ca2+]cyt increase, mitochondrial Ca2+ uptake and Ca2+ refill into the SR were attenuated by Mfn2 knockdown. In addition, Mfn2-knockdown cells exhibited a loss of mitochondrial membrane potential (ΔΨmito) and lower ATP levels in mitochondria. Moreover, Mfn2 knockdown inhibited cell proliferation. In contrast, Mfn2 overexpression increased ΔΨmito and cell growth. This study strongly suggests that Mfn2 is responsible for SR-mitochondria Ca2+ signaling by tethering mitochondria to SR, thereby regulating ATP production and proliferation of VSMCs.
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Affiliation(s)
- Sou Inagaki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Keisuke Kawasaki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Rubii Kondo
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Yuji Imaizumi
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Aichi, Japan
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
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Kondo R, Kawata N, Suzuki Y, Yamamura H. Ca<sup>2+</sup> Signaling and Proliferation <i>via</i> Ca<sup>2+</sup>-Sensing Receptors in Human Hepatic Stellate LX-2 Cells. Biol Pharm Bull 2022; 45:664-667. [DOI: 10.1248/bpb.b22-00103] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Rubii Kondo
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Naoki Kawata
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
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Kondo R, Furukawa N, Deguchi A, Kawata N, Suzuki Y, Imaizumi Y, Yamamura H. Downregulation of Ca 2+-Activated Cl - Channel TMEM16A Mediated by Angiotensin II in Cirrhotic Portal Hypertensive Mice. Front Pharmacol 2022; 13:831311. [PMID: 35370660 PMCID: PMC8966666 DOI: 10.3389/fphar.2022.831311] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/01/2022] [Indexed: 12/29/2022] Open
Abstract
Portal hypertension is defined as an increased pressure in the portal venous system and occurs as a major complication in chronic liver diseases. The pathological mechanism underlying the pathogenesis and development of portal hypertension has been extensively investigated. Vascular tone of portal vein smooth muscles (PVSMs) is regulated by the activities of several ion channels, including Ca2+-activated Cl- (ClCa) channels. TMEM16A is mainly responsible for ClCa channel conductance in vascular smooth muscle cells, including portal vein smooth muscle cells (PVSMCs). In the present study, the functional roles of TMEM16A channels were examined using two experimental portal hypertensive models, bile duct ligation (BDL) mice with cirrhotic portal hypertension and partial portal vein ligation (PPVL) mice with non-cirrhotic portal hypertension. Expression analyses revealed that the expression of TMEM16A was downregulated in BDL-PVSMs, but not in PPVL-PVSMs. Whole-cell ClCa currents were smaller in BDL-PVSMCs than in sham- and PPVL-PVSMCs. The amplitude of spontaneous contractions was smaller and the frequency was higher in BDL-PVSMs than in sham- and PPVL-PVSMs. Spontaneous contractions sensitive to a specific inhibitor of TMEM16A channels, T16Ainh-A01, were reduced in BDL-PVSMs. Furthermore, in normal PVSMs, the downregulation of TMEM16A expression was mimicked by the exposure to angiotensin II, but not to bilirubin. This study suggests that the activity of ClCa channels is attenuated by the downregulation of TMEM16A expression in PVSMCs associated with cirrhotic portal hypertension, which is partly mediated by increased angiotensin II in cirrhosis.
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Affiliation(s)
- Rubii Kondo
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Nami Furukawa
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Akari Deguchi
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Naoki Kawata
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Yuji Imaizumi
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
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Wang Y, Hu X, Huang H, Jin Z, Gao J, Guo Y, Zhong Y, Li Z, Zong X, Wang K, Zhang L, Liu Z. Optimization of 4-arylthiophene-3-carboxylic acid derivatives as inhibitors of ANO1: Lead optimization studies toward their analgesic efficacy for inflammatory pain. Eur J Med Chem 2022; 237:114413. [DOI: 10.1016/j.ejmech.2022.114413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 04/17/2022] [Accepted: 04/21/2022] [Indexed: 11/04/2022]
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Imaizumi Y. Reciprocal Relationship between Ca 2+ Signaling and Ca 2+-Gated Ion Channels as a Potential Target for Drug Discovery. Biol Pharm Bull 2022; 45:1-18. [PMID: 34980771 DOI: 10.1248/bpb.b21-00896] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cellular Ca2+ signaling functions as one of the most common second messengers of various signal transduction pathways in cells and mediates a number of physiological roles in a cell-type dependent manner. Ca2+ signaling also regulates more general and fundamental cellular activities, including cell proliferation and apoptosis. Among ion channels, Ca2+-permeable channels in the plasma membrane as well as endo- and sarcoplasmic reticulum membranes play important roles in Ca2+ signaling by directly contributing to the influx of Ca2+ from extracellular spaces or its release from storage sites, respectively. Furthermore, Ca2+-gated ion channels in the plasma membrane often crosstalk reciprocally with Ca2+ signals and are central to the regulation of cellular functions. This review focuses on the physiological and pharmacological impact of i) Ca2+-gated ion channels as an apparatus for the conversion of cellular Ca2+ signals to intercellularly propagative electrical signals and ii) the opposite feedback regulation of Ca2+ signaling by Ca2+-gated ion channel activities in excitable and non-excitable cells.
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Affiliation(s)
- Yuji Imaizumi
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
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12
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Chen Q, Fang J, Shen H, Chen L, Shi M, Huang X, Miao Z, Gong Y. Roles, molecular mechanisms, and signaling pathways of TMEMs in neurological diseases. Am J Transl Res 2021; 13:13273-13297. [PMID: 35035675 PMCID: PMC8748174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 11/10/2021] [Indexed: 06/14/2023]
Abstract
Transmembrane protein family members (TMEMs) span the entire lipid bilayer and act as channels that allow the transport of specific substances through biofilms. The functions of most TMEMs are unexplored. Numerous studies have shown that TMEMs are involved in the pathophysiological processes of various nervous system diseases, but the specific mechanisms of TMEMs in the pathogenesis of diseases remain unclear. In this review, we discuss the expression, physiological functions, and molecular mechanisms of TMEMs in brain tumors, psychiatric disorders, abnormal motor activity, cobblestone lissencephaly, neuropathic pain, traumatic brain injury, and other disorders of the nervous system. Additionally, we propose that TMEMs may be used as prognostic markers and potential therapeutic targets in patients with various neurological diseases.
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Affiliation(s)
- Qinghong Chen
- Affiliated Hospital of Jiangxi University of Traditional Chinese MedicineNanchang 330006, Jiangxi, China
| | - Junlin Fang
- Department of Acupuncture and Moxibustion, Banan Hospital of Traditional Chinese MedicineChongqing 401320, China
| | - Hui Shen
- Zhangjiagang TCM Hospital Affiliated to Nanjing University of Chinese MedicineSuzhou 215600, Jiangsu, China
| | - Liping Chen
- Zhangjiagang TCM Hospital Affiliated to Nanjing University of Chinese MedicineSuzhou 215600, Jiangsu, China
| | - Mengying Shi
- Zhangjiagang TCM Hospital Affiliated to Nanjing University of Chinese MedicineSuzhou 215600, Jiangsu, China
| | - Xianbao Huang
- Affiliated Hospital of Jiangxi University of Traditional Chinese MedicineNanchang 330006, Jiangxi, China
| | - Zhiwei Miao
- Zhangjiagang TCM Hospital Affiliated to Nanjing University of Chinese MedicineSuzhou 215600, Jiangsu, China
| | - Yating Gong
- Zhangjiagang TCM Hospital Affiliated to Nanjing University of Chinese MedicineSuzhou 215600, Jiangsu, China
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TMEM16A and TMEM16B Modulate Pheromone-Evoked Action Potential Firing in Mouse Vomeronasal Sensory Neurons. eNeuro 2021; 8:ENEURO.0179-21.2021. [PMID: 34433575 PMCID: PMC8445037 DOI: 10.1523/eneuro.0179-21.2021] [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: 04/22/2021] [Revised: 06/21/2021] [Accepted: 07/06/2021] [Indexed: 12/02/2022] Open
Abstract
The mouse vomeronasal system controls several social behaviors. Pheromones and other social cues are detected by sensory neurons in the vomeronasal organ (VNO). Stimuli activate a transduction cascade that leads to membrane potential depolarization, increase in cytosolic Ca2+ level, and increased firing. The Ca2+-activated chloride channels TMEM16A and TMEM16B are co-expressed within microvilli of vomeronasal neurons, but their physiological role remains elusive. Here, we investigate the contribution of each of these channels to vomeronasal neuron firing activity by comparing wild-type (WT) and knock-out (KO) mice. Performing loose-patch recordings from neurons in acute VNO slices, we show that spontaneous activity is modified by Tmem16a KO, indicating that TMEM16A, but not TMEM16B, is active under basal conditions. Upon exposure to diluted urine, a rich source of mouse pheromones, we observe significant changes in activity. Vomeronasal sensory neurons (VSNs) from Tmem16a cKO and Tmem16b KO mice show shorter interspike intervals (ISIs) compared with WT mice, indicating that both TMEM16A and TMEM16B modulate the firing pattern of pheromone-evoked activity in VSNs.
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Chen Q, Kong L, Xu Z, Cao N, Tang X, Gao R, Zhang J, Deng S, Tan C, Zhang M, Wang Y, Zhang L, Ma K, Li L, Si J. The Role of TMEM16A/ERK/NK-1 Signaling in Dorsal Root Ganglia Neurons in the Development of Neuropathic Pain Induced by Spared Nerve Injury (SNI). Mol Neurobiol 2021; 58:5772-5789. [PMID: 34406600 PMCID: PMC8599235 DOI: 10.1007/s12035-021-02520-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 08/04/2021] [Indexed: 12/21/2022]
Abstract
Increasing evidence suggests that transmembrane protein 16A (TMEM16A) in nociceptive neurons is an important molecular component contributing to peripheral pain transduction. The present study aimed to evaluate the role and mechanism of TMEM16A in chronic nociceptive responses elicited by spared nerve injury (SNI). In this study, SNI was used to induce neuropathic pain. Drugs were administered intrathecally. The expression and cellular localization of TMEM16A, the ERK pathway, and NK-1 in the dorsal root ganglion (DRG) were detected by western blot and immunofluorescence. Behavioral tests were used to evaluate the role of TMEM16A and p-ERK in SNI-induced persistent pain and hypersensitivity. The role of TMEM16A in the hyperexcitability of primary nociceptor neurons was assessed by electrophysiological recording. The results show that TMEM16A, p-ERK, and NK-1 are predominantly expressed in small neurons associated with nociceptive sensation. TMEM16A is colocalized with p-ERK/NK-1 in DRG. TMEM16A, the MEK/ERK pathway, and NK-1 are activated in DRG after SNI. ERK inhibitor or TMEM16A antagonist prevents SNI-induced allodynia. ERK and NK-1 are downstream of TMEM16A activation. Electrophysiological recording showed that CaCC current increases and intrathecal application of T16Ainh-A01, a selective TMEM16A inhibitor, reverses the hyperexcitability of DRG neurons harvested from rats after SNI. We conclude that TMEM16A activation in DRG leads to a positive interaction of the ERK pathway with activation of NK-1 production and is involved in the development of neuropathic pain after SNI. Also, the blockade of TMEM16A or inhibition of the downstream ERK pathway or NK-1 upregulation may prevent the development of neuropathic pain.
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Affiliation(s)
- Qinyi Chen
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China.,Department of Anesthesiology, Xiangyang Central Hospital, Affiliated Hospital of Hubei University of Arts and Science, Xiangyang, China.,NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, First Affiliated Hospital, Shihezi University School of Medicine, Shihezi, China
| | - Liangjingyuan Kong
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China.,NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, First Affiliated Hospital, Shihezi University School of Medicine, Shihezi, China
| | - Zhenzhen Xu
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China.,NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, First Affiliated Hospital, Shihezi University School of Medicine, Shihezi, China.,Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Nan Cao
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China.,NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, First Affiliated Hospital, Shihezi University School of Medicine, Shihezi, China
| | - Xuechun Tang
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China.,NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, First Affiliated Hospital, Shihezi University School of Medicine, Shihezi, China
| | - Ruijuan Gao
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China.,NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, First Affiliated Hospital, Shihezi University School of Medicine, Shihezi, China
| | - Jingrong Zhang
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China.,NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, First Affiliated Hospital, Shihezi University School of Medicine, Shihezi, China
| | - Shiyu Deng
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China.,NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, First Affiliated Hospital, Shihezi University School of Medicine, Shihezi, China
| | - Chaoyang Tan
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China.,NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, First Affiliated Hospital, Shihezi University School of Medicine, Shihezi, China.,Department of Security, Karamay Army Division, Xinjiang Uygur Autonomous Region, Chinese People's Liberation Army, Karamay, China
| | - Meng Zhang
- Department of Anesthesiology, Sichuan Academy of Medical Sciences, Sichuan Provincial People's Hospital, Chengdu, China
| | - Yang Wang
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China.,NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, First Affiliated Hospital, Shihezi University School of Medicine, Shihezi, China
| | - Liang Zhang
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China.,NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, First Affiliated Hospital, Shihezi University School of Medicine, Shihezi, China
| | - Ketao Ma
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China.,NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, First Affiliated Hospital, Shihezi University School of Medicine, Shihezi, China
| | - Li Li
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China. .,Department of Physiology, Medical College of Jiaxing University, Jiaxing, China.
| | - Junqiang Si
- Department of Physiology, The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Shihezi University Medical College, Shihezi, China. .,NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases, First Affiliated Hospital, Shihezi University School of Medicine, Shihezi, China. .,Department of Physiology, School of Basic Medicine and Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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15
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Wang Y, Gao J, Zhao S, Song Y, Huang H, Zhu G, Jiao P, Xu X, Zhang G, Wang K, Zhang L, Liu Z. Discovery of 4-arylthiophene-3-carboxylic acid as inhibitor of ANO1 and its effect as analgesic agent. Acta Pharm Sin B 2021; 11:1947-1964. [PMID: 34386330 PMCID: PMC8343189 DOI: 10.1016/j.apsb.2020.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 10/26/2020] [Accepted: 11/04/2020] [Indexed: 02/05/2023] Open
Abstract
Anoctamin 1 (ANO1) is a kind of calcium-activated chloride channel involved in nerve depolarization. ANO1 inhibitors display significant analgesic activity by the local peripheral and intrathecal administration. In this study, several thiophenecarboxylic acid and benzoic acid derivatives were identified as novel ANO1 inhibitors through the shape-based virtual screening, among which the 4-arylthiophene-3-carboxylic acid analogues with the best ANO1 inhibitory activity were designed, synthesized and compound 42 (IC50 = 0.79 μmol/L) was finally obtained. Compound 42 selectively inhibited ANO1 without affecting ANO2 and intracellular Ca2+ concentration. Subsequently, the analgesic effect was investigated by intragastric administration in pain models. Compound 42 significantly attenuated allodynia which was induced by formalin and chronic constriction injury. Through homology modeling and molecular dynamics, the binding site was predicted to be located near the calcium-binding region between α6 and α8. Our study validates ANO1 inhibitors having a significant analgesic effect by intragastric administration and also provides selective molecular tools for ANO1-related research.
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16
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Liu Y, Liu Z, Wang K. The Ca 2+-activated chloride channel ANO1/TMEM16A: An emerging therapeutic target for epithelium-originated diseases? Acta Pharm Sin B 2021; 11:1412-1433. [PMID: 34221860 PMCID: PMC8245819 DOI: 10.1016/j.apsb.2020.12.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/19/2020] [Accepted: 09/14/2020] [Indexed: 02/07/2023] Open
Abstract
Anoctamin 1 (ANO1) or TMEM16A gene encodes a member of Ca2+ activated Cl– channels (CaCCs) that are critical for physiological functions, such as epithelial secretion, smooth muscle contraction and sensory signal transduction. The attraction and interest in ANO1/TMEM16A arise from a decade long investigations that abnormal expression or dysfunction of ANO1 is involved in many pathological phenotypes and diseases, including asthma, neuropathic pain, hypertension and cancer. However, the lack of specific modulators of ANO1 has impeded the efforts to validate ANO1 as a therapeutic target. This review focuses on the recent progress made in understanding of the pathophysiological functions of CaCC ANO1 and the current modulators used as pharmacological tools, hopefully illustrating a broad spectrum of ANO1 channelopathy and a path forward for this target validation.
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Key Words
- ANO1
- ANO1, anoctamin-1
- ASM, airway smooth muscle
- Ang II, angiotensin II
- BBB, blood–brain barrier
- CAMK, Ca2+/calmodulin-dependent protein kinase
- CF, cystic fibrosis
- CFTR, cystic fibrosis transmembrane conductance regulator
- Ca2+-activated Cl– channels (CaCCs)
- CaCCinh-A01
- CaCCs, Ca2+ activated chloride channels
- Cancer
- Cystic fibrosis
- DRG, dorsal root ganglion
- Drug target
- EGFR, epidermal growth factor receptor
- ENaC, epithelial sodium channels
- ER, endoplasmic reticulum
- ESCC, esophageal squamous cell carcinoma
- FRT, fisher rat thyroid
- GI, gastrointestinal
- GIST, gastrointestinal stromal tumor
- GPCR, G-protein coupled receptor
- HNSCC, head and neck squamous cell carcinoma
- HTS, high-throughput screening
- ICC, interstitial cells of Cajal
- IPAH, idiopathic pulmonary arterial hypertension
- MAPK, mitogen-activated protein kinase
- NF-κB, nuclear factor κB
- PAH, pulmonary arterial hypertension
- PAR2, protease activated receptor 2
- PASMC, pulmonary artery smooth muscle cells
- PIP2, phosphatidylinositol 4,5-bisphosphate
- PKD, polycystic kidney disease
- T16Ainh-A01
- TGF-β, transforming growth factor-β
- TMEM16A
- VGCC, voltage gated calcium channel
- VRAC, volume regulated anion channel
- VSMC, vascular smooth muscle cells
- YFP, yellow fluorescent protein
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Affiliation(s)
- Yani Liu
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao 266073, China
- Institute of Innovative Drugs, Qingdao University, Qingdao 266021, China
| | - Zongtao Liu
- Department of Clinical Laboratory, Qingdao Third People's Hospital, Qingdao 266041, China
| | - KeWei Wang
- Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao 266073, China
- Institute of Innovative Drugs, Qingdao University, Qingdao 266021, China
- Corresponding authors.
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17
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The Groovy TMEM16 Family: Molecular Mechanisms of Lipid Scrambling and Ion Conduction. J Mol Biol 2021; 433:166941. [PMID: 33741412 DOI: 10.1016/j.jmb.2021.166941] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/09/2021] [Accepted: 03/09/2021] [Indexed: 12/28/2022]
Abstract
The TMEM16 family of membrane proteins displays a remarkable functional dichotomy - while some family members function as Ca2+-activated anion channels, the majority of characterized TMEM16 homologs are Ca2+-activated lipid scramblases, which catalyze the exchange of phospholipids between the two membrane leaflets. Furthermore, some TMEM16 scramblases can also function as channels. Due to their involvement in important physiological processes, the family has been actively studied ever since their molecular identity was unraveled. In this review, we will summarize the recent advances in the field and how they influenced our view of TMEM16 family function and evolution. Structural, functional and computational studies reveal how relatively small rearrangements in the permeation pathway are responsible for the observed functional duality: while TMEM16 scramblases can adopt both ion- and lipid conductive conformations, TMEM16 channels can only populate the former. Recent data further provides the molecular details of a stepwise activation mechanism, which is initiated by Ca2+ binding and modulated by various cellular factors, including lipids. TMEM16 function and the surrounding membrane properties are inextricably intertwined, with the protein inducing bilayer deformations associated with scrambling, while the surrounding lipids modulate TMEM16 conformation and activity.
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18
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Sánchez-Solano A, Corral N, Segura-Covarrubias G, Guzmán-Hernández ML, Arechiga-Figueroa I, Cruz-Rangel S, Pérez-Cornejo P, Arreola J. Regulation of the Ca 2+-activated chloride channel Anoctamin-1 (TMEM16A) by Ca 2+-induced interaction with FKBP12 and calcineurin. Cell Calcium 2020; 89:102211. [PMID: 32422433 DOI: 10.1016/j.ceca.2020.102211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/30/2020] [Accepted: 04/23/2020] [Indexed: 12/26/2022]
Abstract
Chloride fluxes through the calcium-gated chloride channel Anoctamin-1 (TMEM16A) control blood pressure, secretion of saliva, mucin, insulin, and melatonin, gastrointestinal motility, sperm capacitation and motility, and pain sensation. Calcium activates a myriad of regulatory proteins but how these proteins affect TMEM16A activity is unresolved. Here we show by co-immunoprecipitation that increasing intracellular calcium with ionomycin or by activating sphingosine-1-phosphate receptors, induces coupling of calcium/calmodulin-dependent phosphatase calcineurin and prolyl isomerase FK506-binding protein 12 (FKBP12) to TMEM16A in HEK-293 cells. Application of drugs that target either calcineurin (cyclosporine A) or FKBP12 (tacrolimus known as FK506 and sirolimus known as rapamycin) caused a decrease in TMEM16A activity. In addition, FK506 and BAPTA-AM prevented co-immunoprecipitation between FKBP12 and TMEM16A. FK506 rendered the channel insensitive to cyclosporine A without altering its apparent calcium sensitivity whereas zero intracellular calcium blocked the effect of FK506. Rapamycin decreased TMEM16A activity in cells pre-treated with cyclosporine A or FK506. These results suggest the formation of a TMEM16A-FKBP12-calcineurin complex that regulates channel function. We conclude that upon a cytosolic calcium increase the TMEM16A-FKPB12-calcineurin trimers are assembled. Such hetero-oligomerization enhances TMEM16A channel activity but is not mandatory for activation by calcium.
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Affiliation(s)
- Alfredo Sánchez-Solano
- Physics Institute, Universidad Autónoma de San Luis Potosí, Ave. Dr. Manuel Nava #6, San Luis Potosí, SLP 78290, Mexico
| | - Nancy Corral
- Department of Physiology and Biophysics, Universidad Autónoma de San Luis Potosí School of Medicine, Ave. V. Carranza 2405, San Luis Potosí, SLP 78290, Mexico
| | - Guadalupe Segura-Covarrubias
- Physics Institute, Universidad Autónoma de San Luis Potosí, Ave. Dr. Manuel Nava #6, San Luis Potosí, SLP 78290, Mexico
| | - María Luisa Guzmán-Hernández
- Cátedra CONACYT, School of Medicine, Universidad Autónoma de San Luis Potosí, Ave. V. Carranza 2405, San Luis Potosí, SLP 78290, Mexico
| | - Ivan Arechiga-Figueroa
- Cátedra CONACYT, School of Medicine, Universidad Autónoma de San Luis Potosí, Ave. V. Carranza 2405, San Luis Potosí, SLP 78290, Mexico
| | - Silvia Cruz-Rangel
- Physics Institute, Universidad Autónoma de San Luis Potosí, Ave. Dr. Manuel Nava #6, San Luis Potosí, SLP 78290, Mexico
| | - Patricia Pérez-Cornejo
- Department of Physiology and Biophysics, Universidad Autónoma de San Luis Potosí School of Medicine, Ave. V. Carranza 2405, San Luis Potosí, SLP 78290, Mexico
| | - Jorge Arreola
- Physics Institute, Universidad Autónoma de San Luis Potosí, Ave. Dr. Manuel Nava #6, San Luis Potosí, SLP 78290, Mexico.
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19
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Suzuki T, Yasumoto M, Suzuki Y, Asai K, Imaizumi Y, Yamamura H. TMEM16A Ca 2+-Activated Cl - Channel Regulates the Proliferation and Migration of Brain Capillary Endothelial Cells. Mol Pharmacol 2020; 98:61-71. [PMID: 32358165 DOI: 10.1124/mol.119.118844] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 04/20/2020] [Indexed: 11/22/2022] Open
Abstract
The blood-brain barrier (BBB) is essential for the maintenance of homeostasis in the brain. Brain capillary endothelial cells (BCECs) comprise the BBB, and thus a delicate balance between their proliferation and death is required. Although the activity of ion channels in BCECs is involved in BBB functions, the underlying molecular mechanisms remain unclear. In the present study, the molecular components of Ca2+-activated Cl- (ClCa) channels and their physiological roles were examined using mouse BCECs (mBCECs) and a cell line derived from bovine BCECs, t-BBEC117. Expression analyses revealed that TMEM16A was strongly expressed in mBCECs and t-BBEC117 cells. In t-BBEC117 cells, whole-cell Cl- currents were sensitive to the ClCa channel blockers, 100 μM niflumic acid and 10 μM T16Ainh-A01, and were also reduced markedly by small-interfering RNA (siRNA) knockdown of TMEM16A. Importantly, block of ClCa currents with ClCa channel blockers or TMEM16A siRNA induced membrane hyperpolarization. Moreover, treatment with TMEM16A siRNA caused an increase in resting cytosolic Ca2+ concentration ([Ca2+]cyt). T16Ainh-A01 reduced cell viability in a concentration-dependent manner. Either ClCa channel blockers or TMEM16A siRNA also curtailed cell proliferation and migration. Furthermore, ClCa channel blockers attenuated the trans-endothelial permeability. In combination, these results strongly suggest that TMEM16A contributes to ClCa channel conductance and can regulate both the resting membrane potential and [Ca2+]cyt in BCECs. Our data also reveal how these BCECs may be involved in the maintenance of BBB functions, as both the proliferation and migration are altered following changes in channel activity. SIGNIFICANCE STATEMENT: In brain capillary endothelial cells (BCECs) of the blood-brain barrier (BBB), TMEM16A is responsible for Ca2+-activated Cl- channels and can regulate both the resting membrane potential and cytosolic Ca2+ concentration, contributing to the proliferation and migration of BCECs. The present study provides novel information on the molecular mechanisms underlying the physiological functions of BCECs in the BBB and a novel target for therapeutic drugs for disorders associated with dysfunctions in the BBB.
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Affiliation(s)
- Takahisa Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences (T.S., M.Y., Y.S., Y.I., H.Y.) and Department of Molecular Neurobiology, Graduate School of Medical Sciences (K.A.), Nagoya City University, Nagoya, Japan
| | - Miki Yasumoto
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences (T.S., M.Y., Y.S., Y.I., H.Y.) and Department of Molecular Neurobiology, Graduate School of Medical Sciences (K.A.), Nagoya City University, Nagoya, Japan
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences (T.S., M.Y., Y.S., Y.I., H.Y.) and Department of Molecular Neurobiology, Graduate School of Medical Sciences (K.A.), Nagoya City University, Nagoya, Japan
| | - Kiyofumi Asai
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences (T.S., M.Y., Y.S., Y.I., H.Y.) and Department of Molecular Neurobiology, Graduate School of Medical Sciences (K.A.), Nagoya City University, Nagoya, Japan
| | - Yuji Imaizumi
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences (T.S., M.Y., Y.S., Y.I., H.Y.) and Department of Molecular Neurobiology, Graduate School of Medical Sciences (K.A.), Nagoya City University, Nagoya, Japan
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences (T.S., M.Y., Y.S., Y.I., H.Y.) and Department of Molecular Neurobiology, Graduate School of Medical Sciences (K.A.), Nagoya City University, Nagoya, Japan
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20
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Noda S, Chikazawa K, Suzuki Y, Imaizumi Y, Yamamura H. Involvement of the γ1 subunit of the large-conductance Ca 2+-activated K + channel in the proliferation of human somatostatinoma cells. Biochem Biophys Res Commun 2020; 525:1032-1037. [PMID: 32178873 DOI: 10.1016/j.bbrc.2020.02.176] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 02/28/2020] [Indexed: 10/24/2022]
Abstract
Pancreatic neuroendocrine tumors (pNETs) occur due to the abnormal growth of pancreatic islet cells and predominantly develop in the duodenal-pancreatic region. Somatostatinoma is one of the pNETs associated with tumors of pancreatic δ cells, which produce and secrete somatostatin. Limited information is currently available on the pathogenic mechanisms of somatostatinoma. The large-conductance Ca2+-activated K+ (BKCa) channel is expressed in several types of cancer cells and regulates cell proliferation, migration, invasion, and metastasis. In the present study, the functional expression of the BKCa channel was examined in a human somatostatinoma QGP-1 cell line. In QGP-1 cells, outward currents were elicited by membrane depolarization at pCa 6.5 (300 nM) in the pipette solution and inhibited by the specific BKCa channel blocker, paxilline. Paxilline-sensitive currents were detected, even at pCa 8.0 (10 nM) in the pipette solution, in QGP-1 cells. In addition to the α and β2-4 subunits of the BKCa channel, the novel regulatory γ1 subunit (BKCaγ1) was co-localized with the α subunit in QGP-1 cells. Paxilline-sensitive currents at pCa 8.0 in the pipette solution were reduced by the siRNA knockdown of BKCaγ1. Store-operated Ca2+ entry was smaller in BKCaγ1 siRNA-treated QGP-1 cells. The proliferation of QGP-1 cells was attenuated by paxilline or the siRNA knockdown of BKCaγ1. These results strongly suggest that BKCaγ1 facilitates the proliferation of human somatostatinoma cells. Therefore, BKCaγ1 may be a novel therapeutic target for somatostatinoma.
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Affiliation(s)
- Sayuri Noda
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Kana Chikazawa
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Yuji Imaizumi
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabedori Mizuhoku, Nagoya, 467-8603, Japan.
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21
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Kodirov SA. Tale of tail current. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 150:78-97. [PMID: 31238048 DOI: 10.1016/j.pbiomolbio.2019.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/22/2019] [Accepted: 06/20/2019] [Indexed: 02/07/2023]
Abstract
The largest biomass of channel proteins is located in unicellular organisms and bacteria that have no organs. However, orchestrated bidirectional ionic currents across the cell membrane via the channels are important for the functioning of organs of organisms, and equally concern both fauna or flora. Several ion channels are activated in the course of action potentials. One of the hallmarks of voltage-dependent channels is a 'tail current' - deactivation as observed after prior and sufficient activation predominantly at more depolarized potentials e.g. for Kv while upon hyperpolarization for HCN α subunits. Tail current also reflects the timing of channel closure that is initiated upon termination of stimuli. Finally, deactivation of currents during repolarization could be a selective estimate for given channel as in case of HERG, if dedicated long and more depolarized 'tail pulse' is used. Since from a holding potential of e.g. -70 mV are often a family of outward K+ currents comprising IA and IK are simultaneously activated in native cells.
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Affiliation(s)
- Sodikdjon A Kodirov
- Pavlov Institute of Physiology, Russian Academy of Sciences, Saint Petersburg, Russia; Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, 02115, USA; Almazov Federal Heart, Blood and Endocrinology Centre, Saint Petersburg, 197341, Russia; Institute of Experimental Medicine, I. P. Pavlov Department of Physiology, Russian Academy of Medical Sciences, Saint Petersburg, Russia; Laboratory of Emotions' Neurobiology, Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw, 02-093, Poland.
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22
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Tong JJ, Acharya P, Ebihara L. Calcium-Activated Chloride Channels in Newly Differentiating Mouse Lens Fiber Cells and Their Role in Volume Regulation. Invest Ophthalmol Vis Sci 2019; 60:1621-1629. [PMID: 30995319 PMCID: PMC6736345 DOI: 10.1167/iovs.19-26626] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 03/14/2019] [Indexed: 11/24/2022] Open
Abstract
Purpose Chloride channels have been proposed to play an important role in the regulation of lens volume. Unfortunately, little information is available about the molecular identity of these channels or how they are regulated in the lens due to the difficulties in isolating mouse fiber cells. Recently, our laboratory has developed a new technique for isolating these cells by using transgenic mouse lenses that lack both Cx50 and Cx46. The purpose of this study was to test the hypothesis that newly differentiating mouse fiber cells express calcium-activated chloride channels (CaCCs) by using this technique. Methods Differentiating fiber cells were isolated from lenses of double knockout mice that lack both Cx50 and Cx46 by using collagenase. Membrane currents were studied using the whole-cell patch clamp technique. The molecular identity and distribution of CaCCs were investigated using RT-PCR and immunofluorescence. Results Our electrophysiologic experiments suggest that peripheral fiber cells express a calcium-activated chloride current. The voltage gating properties, calcium sensitivity, and pharmacologic properties of this current resembled those of TMEM16 CaCCs. RT-PCR analysis demonstrated the presence of TMEM16A and TMEM16B transcripts in wild-type and double knockout mouse lenses. Both TMEM16A and TMEM16B proteins were detected in the differentiating epithelial cells and newly elongating fiber cells near the equator of the lens by immunohistochemistry. Conclusions Our results demonstrate that membrane conductance of peripheral fiber cells contain CaCCs that can be attributed to TMEM16A and TMEM16B. Given their critical role in volume regulation in other tissues, we speculate that these channels play a similar role in the lens.
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Affiliation(s)
- Jun-Jie Tong
- Department of Physiology and Biophysics, Rosalind Franklin University of Medicine and Science, Chicago, Illinois, United States
| | - Pooja Acharya
- Department of Physiology and Biophysics, Rosalind Franklin University of Medicine and Science, Chicago, Illinois, United States
| | - Lisa Ebihara
- Department of Physiology and Biophysics, Rosalind Franklin University of Medicine and Science, Chicago, Illinois, United States
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23
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Okada Y, Okada T, Sato-Numata K, Islam MR, Ando-Akatsuka Y, Numata T, Kubo M, Shimizu T, Kurbannazarova RS, Marunaka Y, Sabirov RZ. Cell Volume-Activated and Volume-Correlated Anion Channels in Mammalian Cells: Their Biophysical, Molecular, and Pharmacological Properties. Pharmacol Rev 2019; 71:49-88. [PMID: 30573636 DOI: 10.1124/pr.118.015917] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
There are a number of mammalian anion channel types associated with cell volume changes. These channel types are classified into two groups: volume-activated anion channels (VAACs) and volume-correlated anion channels (VCACs). VAACs can be directly activated by cell swelling and include the volume-sensitive outwardly rectifying anion channel (VSOR), which is also called the volume-regulated anion channel; the maxi-anion channel (MAC or Maxi-Cl); and the voltage-gated anion channel, chloride channel (ClC)-2. VCACs can be facultatively implicated in, although not directly activated by, cell volume changes and include the cAMP-activated cystic fibrosis transmembrane conductance regulator (CFTR) anion channel, the Ca2+-activated Cl- channel (CaCC), and the acid-sensitive (or acid-stimulated) outwardly rectifying anion channel. This article describes the phenotypical properties and activation mechanisms of both groups of anion channels, including accumulating pieces of information on the basis of recent molecular understanding. To that end, this review also highlights the molecular identities of both anion channel groups; in addition to the molecular identities of ClC-2 and CFTR, those of CaCC, VSOR, and Maxi-Cl were recently identified by applying genome-wide approaches. In the last section of this review, the most up-to-date information on the pharmacological properties of both anion channel groups, especially their half-maximal inhibitory concentrations (IC50 values) and voltage-dependent blocking, is summarized particularly from the standpoint of pharmacological distinctions among them. Future physiologic and pharmacological studies are definitely warranted for therapeutic targeting of dysfunction of VAACs and VCACs.
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Affiliation(s)
- Yasunobu Okada
- Departments of Physiology and Systems Bioscience (Y.O.) and Molecular Cell Physiology (Y.M.), Kyoto Prefectural University of Medicine, Kyoto, Japan; Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Japan (Y.O., T.O., M.R.I., M.K., R.Z.S.); Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan (K.S.-N., T.N.); Department of Cell Physiology, Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan (Y.A.-A.); Department of Pharmaceutical Physiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan (T.S.); Laboratory of Molecular Physiology, Institute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan (R.S.K., R.Z.S.); and Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto, Japan (Y.M.)
| | - Toshiaki Okada
- Departments of Physiology and Systems Bioscience (Y.O.) and Molecular Cell Physiology (Y.M.), Kyoto Prefectural University of Medicine, Kyoto, Japan; Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Japan (Y.O., T.O., M.R.I., M.K., R.Z.S.); Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan (K.S.-N., T.N.); Department of Cell Physiology, Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan (Y.A.-A.); Department of Pharmaceutical Physiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan (T.S.); Laboratory of Molecular Physiology, Institute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan (R.S.K., R.Z.S.); and Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto, Japan (Y.M.)
| | - Kaori Sato-Numata
- Departments of Physiology and Systems Bioscience (Y.O.) and Molecular Cell Physiology (Y.M.), Kyoto Prefectural University of Medicine, Kyoto, Japan; Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Japan (Y.O., T.O., M.R.I., M.K., R.Z.S.); Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan (K.S.-N., T.N.); Department of Cell Physiology, Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan (Y.A.-A.); Department of Pharmaceutical Physiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan (T.S.); Laboratory of Molecular Physiology, Institute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan (R.S.K., R.Z.S.); and Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto, Japan (Y.M.)
| | - Md Rafiqul Islam
- Departments of Physiology and Systems Bioscience (Y.O.) and Molecular Cell Physiology (Y.M.), Kyoto Prefectural University of Medicine, Kyoto, Japan; Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Japan (Y.O., T.O., M.R.I., M.K., R.Z.S.); Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan (K.S.-N., T.N.); Department of Cell Physiology, Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan (Y.A.-A.); Department of Pharmaceutical Physiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan (T.S.); Laboratory of Molecular Physiology, Institute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan (R.S.K., R.Z.S.); and Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto, Japan (Y.M.)
| | - Yuhko Ando-Akatsuka
- Departments of Physiology and Systems Bioscience (Y.O.) and Molecular Cell Physiology (Y.M.), Kyoto Prefectural University of Medicine, Kyoto, Japan; Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Japan (Y.O., T.O., M.R.I., M.K., R.Z.S.); Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan (K.S.-N., T.N.); Department of Cell Physiology, Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan (Y.A.-A.); Department of Pharmaceutical Physiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan (T.S.); Laboratory of Molecular Physiology, Institute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan (R.S.K., R.Z.S.); and Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto, Japan (Y.M.)
| | - Tomohiro Numata
- Departments of Physiology and Systems Bioscience (Y.O.) and Molecular Cell Physiology (Y.M.), Kyoto Prefectural University of Medicine, Kyoto, Japan; Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Japan (Y.O., T.O., M.R.I., M.K., R.Z.S.); Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan (K.S.-N., T.N.); Department of Cell Physiology, Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan (Y.A.-A.); Department of Pharmaceutical Physiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan (T.S.); Laboratory of Molecular Physiology, Institute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan (R.S.K., R.Z.S.); and Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto, Japan (Y.M.)
| | - Machiko Kubo
- Departments of Physiology and Systems Bioscience (Y.O.) and Molecular Cell Physiology (Y.M.), Kyoto Prefectural University of Medicine, Kyoto, Japan; Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Japan (Y.O., T.O., M.R.I., M.K., R.Z.S.); Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan (K.S.-N., T.N.); Department of Cell Physiology, Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan (Y.A.-A.); Department of Pharmaceutical Physiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan (T.S.); Laboratory of Molecular Physiology, Institute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan (R.S.K., R.Z.S.); and Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto, Japan (Y.M.)
| | - Takahiro Shimizu
- Departments of Physiology and Systems Bioscience (Y.O.) and Molecular Cell Physiology (Y.M.), Kyoto Prefectural University of Medicine, Kyoto, Japan; Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Japan (Y.O., T.O., M.R.I., M.K., R.Z.S.); Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan (K.S.-N., T.N.); Department of Cell Physiology, Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan (Y.A.-A.); Department of Pharmaceutical Physiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan (T.S.); Laboratory of Molecular Physiology, Institute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan (R.S.K., R.Z.S.); and Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto, Japan (Y.M.)
| | - Ranohon S Kurbannazarova
- Departments of Physiology and Systems Bioscience (Y.O.) and Molecular Cell Physiology (Y.M.), Kyoto Prefectural University of Medicine, Kyoto, Japan; Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Japan (Y.O., T.O., M.R.I., M.K., R.Z.S.); Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan (K.S.-N., T.N.); Department of Cell Physiology, Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan (Y.A.-A.); Department of Pharmaceutical Physiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan (T.S.); Laboratory of Molecular Physiology, Institute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan (R.S.K., R.Z.S.); and Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto, Japan (Y.M.)
| | - Yoshinori Marunaka
- Departments of Physiology and Systems Bioscience (Y.O.) and Molecular Cell Physiology (Y.M.), Kyoto Prefectural University of Medicine, Kyoto, Japan; Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Japan (Y.O., T.O., M.R.I., M.K., R.Z.S.); Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan (K.S.-N., T.N.); Department of Cell Physiology, Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan (Y.A.-A.); Department of Pharmaceutical Physiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan (T.S.); Laboratory of Molecular Physiology, Institute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan (R.S.K., R.Z.S.); and Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto, Japan (Y.M.)
| | - Ravshan Z Sabirov
- Departments of Physiology and Systems Bioscience (Y.O.) and Molecular Cell Physiology (Y.M.), Kyoto Prefectural University of Medicine, Kyoto, Japan; Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki, Japan (Y.O., T.O., M.R.I., M.K., R.Z.S.); Department of Physiology, School of Medicine, Fukuoka University, Fukuoka, Japan (K.S.-N., T.N.); Department of Cell Physiology, Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Japan (Y.A.-A.); Department of Pharmaceutical Physiology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan (T.S.); Laboratory of Molecular Physiology, Institute of Bioorganic Chemistry, Academy of Sciences of Uzbekistan, Tashkent, Uzbekistan (R.S.K., R.Z.S.); and Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto, Japan (Y.M.)
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Chen QY, Tan CY, Wang Y, Ma KT, Li L, Si JQ. Mechanism of persistent hyperalgesia in neuropathic pain caused by chronic constriction injury. Neural Regen Res 2019; 14:1091-1098. [PMID: 30762024 PMCID: PMC6404508 DOI: 10.4103/1673-5374.250631] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Transmembrane member 16A (TMEM16A) is involved in many physiological functions, such as epithelial secretion, sensory conduction, nociception, control of neuronal excitability, and regulation of smooth muscle contraction, and may be important in peripheral pain transmission. To explore the role of TMEM16A in the persistent hyperalgesia that results from chronic constriction injury-induced neuropathic pain, a rat model of the condition was established by ligating the left sciatic nerve. A TMEM16A selective antagonist (10 μg T16Ainh-A01) was intrathecally injected at L5-6. For measurement of thermal hyperalgesia, the drug was administered once at 14 days and thermal withdrawal latency was recorded with an analgesia meter. For measurement of other indexes, the drug was administered at 12 days, once every 6 hours, totally five times. The measurements were performed at 14 days. Western blot assay was conducted to analyze TMEM16A expression in the L4-6 dorsal root ganglion. Immunofluorescence staining was used to detect the immunoreactivity of TMEM16A in the L4-6 dorsal root ganglion on the injured side. Patch clamp was used to detect electrophysiological changes in the neurons in the L4-6 dorsal root ganglion. Our results demonstrated that thermal withdrawal latency was shortened in the model rats compared with control rats. Additionally, TMEM16A expression and the number of TMEM16A positive cells in the L4-6 dorsal root ganglion were higher in the model rats, which induced excitation of the neurons in the L4-6 dorsal root ganglion. These findings were inhibited by T16Ainh-A01 and confirm that TMEM16A plays a key role in persistent chronic constriction injury-induced hyperalgesia. Thus, inhibiting TMEM16A might be a novel pharmacological intervention for neuropathic pain. All experimental protocols were approved by the Animal Ethics Committee at the First Affiliated Hospital of Shihezi University School of Medicine, China (approval No. A2017-170-01) on February 27, 2017.
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Affiliation(s)
- Qin-Yi Chen
- Department of Anesthesiology, First Affiliated Hospital of Shihezi University; Department of Physiology, Medical College of Shihezi University; Key Laboratory of Xinjiang Endemic and Ethnic Disease, Shihezi University School of Medicine, Shihezi, Xinjiang Uygur Autonomous Region, China
| | - Chao-Yang Tan
- Department of Physiology, Medical College of Shihezi University; Key Laboratory of Xinjiang Endemic and Ethnic Disease, Shihezi University School of Medicine, Shihezi, Xinjiang Uygur Autonomous Region, China
| | - Yang Wang
- Department of Physiology, Medical College of Shihezi University; Key Laboratory of Xinjiang Endemic and Ethnic Disease, Shihezi University School of Medicine, Shihezi, Xinjiang Uygur Autonomous Region, China
| | - Ke-Tao Ma
- Department of Physiology, Medical College of Shihezi University; Key Laboratory of Xinjiang Endemic and Ethnic Disease, Shihezi University School of Medicine, Shihezi, Xinjiang Uygur Autonomous Region, China
| | - Li Li
- Department of Physiology, Medical College of Shihezi University; Key Laboratory of Xinjiang Endemic and Ethnic Disease, Shihezi University School of Medicine, Shihezi, Xinjiang Uygur Autonomous Region, China
| | - Jun-Qiang Si
- Department of Physiology, Medical College of Shihezi University; Key Laboratory of Xinjiang Endemic and Ethnic Disease, Shihezi University School of Medicine, Shihezi, Xinjiang Uygur Autonomous Region; Department of Neurobiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
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Yamamura H, Suzuki Y, Imaizumi Y. Physiological and Pathological Functions of Cl - Channels in Chondrocytes. Biol Pharm Bull 2018; 41:1145-1151. [PMID: 30068862 DOI: 10.1248/bpb.b18-00152] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Articular chondrocytes are embedded in the cartilage of diarthrodial joints and responsible for the synthesis and secretion of extracellular matrix. The extracellular matrix mainly contains collagens and proteoglycans, and covers the articular cartilage to protect from mechanical and biochemical stresses. In mammalian chondrocytes, various types of ion channels have been identified: e.g., voltage-dependent K+ channels, Ca2+-activated K+ channels, ATP-sensitive K+ channels, two-pore domain K+ channels, voltage-dependent Ca2+ channels, store-operated Ca2+ channels, epithelial Na+ channels, acid-sensing ion channels, transient receptor potential channels, and mechanosensitive channels. These channels play important roles for the regulation of resting membrane potential, Ca2+ signaling, pH sensing, mechanotransduction, and cell proliferation in articular chondrocytes. In addition to these cation channels, Cl- channels are known to be expressed in mammalian chondrocytes: e.g., voltage-dependent Cl- channels, cystic fibrosis transmembrane conductance regulator channels, swelling-activated Cl- channels, and Ca2+-activated Cl- channels. Although these chondrocyte Cl- channels are thought to contribute to the regulation of resting membrane potential, Ca2+ signaling, cell volume, cell survival, and endochondral bone formation, the physiological functions have not been fully clarified. Osteoarthritis (OA) is caused by the degradation of articular cartilage, resulting in inflammation and pain in the joints. Therefore the pathophysiological roles of Cl- channels in OA chondrocytes are of considerable interest. Elucidating the physiological and pathological functions of chondrocyte Cl- channels will provide us a more comprehensive understanding of chondrocyte functions and may suggest novel molecular targets of drug development for OA.
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Affiliation(s)
- Hisao Yamamura
- Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Yoshiaki Suzuki
- Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Yuji Imaizumi
- Department of Molecular & Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
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