1
|
Salomon JJ, Albrecht T, Graeber SY, Scheuermann H, Butz S, Schatterny J, Mairbäurl H, Baumann I, Mall MA. Chronic rhinosinusitis with nasal polyps is associated with impaired TMEM16A-mediated epithelial chloride secretion. J Allergy Clin Immunol 2021; 147:2191-2201.e2. [PMID: 33609628 DOI: 10.1016/j.jaci.2021.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 01/16/2021] [Accepted: 02/12/2021] [Indexed: 01/10/2023]
Abstract
BACKGROUND Chronic rhinosinusitis with nasal polyps (CRSwNP) is one of the most common chronic disorders with limited therapeutic options. However, the pathogenesis of CRSwNP remains poorly understood. OBJECTIVE We sought to determine the role of abnormalities in nasal epithelial ion transport in primary epithelial cultures and patients with CRSwNP. METHODS We studied epithelial ion transport and transcript levels of the Cl- channels cystic fibrosis transmembrane conductance regulator and transmembrane protein 16A (TMEM16A) in human primary nasal epithelial cultures of patients with CRSwNP and healthy controls. Furthermore, we determined expression levels of proinflammatory cytokines that have been implicated in the regulation of epithelial ion channels (IL-1β, INF-γ, TNF-α, IL-13) and studied effects of the key TH2 signaling molecule IL-13 in CRSwNP and control nasal epithelial cultures. Finally, we measured in vivo nasal potential difference to compare epithelial ion transport in patients with CRSwNP and controls. RESULTS Bioelectric studies demonstrated that Ca2+-activated Cl- secretion was reduced in CRSwNP versus control nasal epithelial cultures. Transcript levels of IL-13 and the Ca2+-activated Cl- channel TMEM16A were increased in CRSwNP cultures. Stimulation with IL-13 increased TMEM16A expression further and restored Ca2+-activated Cl- secretion in CRSwNP cultures. Nasal potential difference measurements demonstrated reduced Ca2+-activated Cl- transport in patients with CRSwNP versus controls. CONCLUSIONS This study demonstrates that TMEM16A-mediated Ca2+-activated Cl- secretion is reduced in primary nasal epithelial cultures and nasal epithelia of patients with CRSwNP. Our data suggest that the Ca2+-activated Cl- channel TMEM16A may be implicated in the pathogenesis and serve as a novel therapeutic target in patients with CRSwNP.
Collapse
Affiliation(s)
- Johanna J Salomon
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Tobias Albrecht
- Department of Otolaryngology, Head and Neck Surgery, University of Heidelberg, Heidelberg, Germany
| | - Simon Y Graeber
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany; Department of Pediatric Pulmonology, Immunology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany; Berlin Institute of Health (BIH), Berlin, Germany; German Centre for Lung Research (DZL), associated partner site, Berlin, Germany
| | - Heike Scheuermann
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Simone Butz
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Jolanthe Schatterny
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Heimo Mairbäurl
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Ingo Baumann
- Department of Otolaryngology, Head and Neck Surgery, University of Heidelberg, Heidelberg, Germany
| | - Marcus A Mall
- Department of Translational Pulmonology, Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany; Department of Pediatric Pulmonology, Immunology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany; Berlin Institute of Health (BIH), Berlin, Germany; German Centre for Lung Research (DZL), associated partner site, Berlin, Germany.
| |
Collapse
|
2
|
Abstract
Bestrophin-1 (BEST1) is a calcium-activated chloride channel (CaCC) predominantly expressed at the basolateral membrane of the retinal pigment epithelium (RPE). Over 250 mutations in the BEST1 gene have been documented to cause at least five retinal degenerative disorders, commonly termed bestrophinopathies, to which no treatment is currently available. Therefore, understanding the influences of BEST1 disease-causing mutations on the physiological function of BEST1 in RPE is critical for deciphering the pathology of bestrophinopathies and developing therapeutic strategies for patients. However, this task has been impeded by the rarity of BEST1 mutations and limited accessibility to native human RPE cells. Here, we describe a pluripotent stem cell (PSC)-based pipeline for reproducibly generating RPE cells expressing endogenous or exogenous mutant BEST1, which provides us with a powerful "disease-in-a-dish" approach for studying BEST1 mutations in physiological environments.
Collapse
Affiliation(s)
- Alec Kittredge
- Department of Molecular Pharmacology and Therapeutics, Columbia University, New York, NY, United States
| | - Yu Zhang
- Department of Ophthalmology, Columbia University, New York, NY, United States,Corresponding authors: ; ;
| | - Tingting Yang
- Department of Ophthalmology, Columbia University, New York, NY, United States,Corresponding authors: ; ;
| |
Collapse
|
3
|
Fujimoto M, Inoue T, Kito H, Niwa S, Suzuki T, Muraki K, Ohya S. Transcriptional repression of HER2 by ANO1 Cl - channel inhibition in human breast cancer cells with resistance to trastuzumab. Biochem Biophys Res Commun 2016; 482:188-194. [PMID: 27838298 DOI: 10.1016/j.bbrc.2016.11.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 11/07/2016] [Indexed: 01/16/2023]
Abstract
The Ca2+-activated Cl- channel ANO1 contributes to tumorigenesis and metastasis in several carcinomas including breast cancer (BCA). Cl- channels have recently been attracting attention as 'transcriptional modulators'. Human epidermal growth factor receptor 2 (HER2) is overexpressed in approximately 30% of patients with BCA, and anti-HER2 monoclonal antibodies such as trastuzumab have emerged as a treatment for metastatic BCA. Among the seven human BCA cell lines examined in the present study, MDA-MB-453 and YMB-1 cells were HER2-positive; however, YMB-1 cell viability showed resistance to trastuzumab. Whole-cell patch-clamp configurations indicated that ANO1 was the main Cl- conductance in YMB-1 cells, and the pharmacological and siRNA-mediated inhibition of ANO1 significantly prevented HER2 transcription in YMB-1 cells. The expression levels of insulin-like growth factor-binding protein 5 (IGFBP5), which is a risk factor for BCA recurrence and metastasis, was not affected by the inhibition of ANO1 in YMB-1 cells. These results suggest that ANO1 Cl- channels may function as a transcriptional regulator of HER2, and ANO1 inhibitors have potential in the treatment of BCA patients with resistance to HER2-targeted therapy.
Collapse
Affiliation(s)
- Mayu Fujimoto
- Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Takahiro Inoue
- Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Hiroaki Kito
- Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Satomi Niwa
- Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Takayoshi Suzuki
- Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 603-8334, Japan
| | - Katsuhiko Muraki
- Laboratory of Cellular Pharmacology, School of Pharmacy, Aichi-Gakuin University, Nagoya 464-8650, Japan
| | - Susumu Ohya
- Department of Pharmacology, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| |
Collapse
|
4
|
Abstract
A number of different ion channel types are involved in cell signaling networks, and homeostatic regulatory mechanisms contribute to the control of ion channel expression. Profiling of global gene expression using microarray technology has recently provided novel insights into the molecular mechanisms underlying the homeostatic and pathological control of ion channel expression. It has demonstrated that the dysregulation of ion channel expression is associated with the pathogenesis of neural, cardiovascular, and immune diseases as well as cancers. In addition to the transcriptional, translational, and post-translational regulation of ion channels, potentially important evidence on the mechanisms controlling ion channel expression has recently been accumulated. The regulation of alternative pre-mRNA splicing is therefore a novel therapeutic strategy for the treatment of dominant-negative splicing disorders. Epigenetic modification plays a key role in various pathological conditions through the regulation of pluripotency genes. Inhibitors of pre-mRNA splicing and histone deacetyalase/methyltransferase have potential as potent therapeutic drugs for cancers and autoimmune and inflammatory diseases. Moreover, membrane-anchoring proteins, lysosomal and proteasomal degradation-related molecules, auxiliary subunits, and pharmacological agents alter the protein folding, membrane trafficking, and post-translational modifications of ion channels, and are linked to expression-defect channelopathies. In this review, we focused on recent insights into the transcriptional, spliceosomal, epigenetic, and proteasomal regulation of ion channel expression: Ca(2+) channels (TRPC/TRPV/TRPM/TRPA/Orai), K(+) channels (voltage-gated, KV/Ca(2+)-activated, KCa/two-pore domain, K2P/inward-rectifier, Kir), and Ca(2+)-activated Cl(-) channels (TMEM16A/TMEM16B). Furthermore, this review highlights expression of these ion channels in expression-defect channelopathies.
Collapse
Affiliation(s)
- Susumu Ohya
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Hiroaki Kito
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan
| | - Noriyuki Hatano
- Laboratory of Cellular Pharmacology, School of Pharmacy, Aichi-Gakuin University, Nagoya 464-8650, Japan
| | - Katsuhiko Muraki
- Laboratory of Cellular Pharmacology, School of Pharmacy, Aichi-Gakuin University, Nagoya 464-8650, Japan.
| |
Collapse
|
5
|
Wang B, Li C, Huai R, Qu Z. Overexpression of ANO1/TMEM16A, an arterial Ca2+-activated Cl- channel, contributes to spontaneous hypertension. J Mol Cell Cardiol 2015; 82:22-32. [PMID: 25739000 DOI: 10.1016/j.yjmcc.2015.02.020] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 02/11/2015] [Accepted: 02/23/2015] [Indexed: 12/21/2022]
Abstract
Calcium-activated chloride channels (CaCCs) have been implicated in hypertension; however, the mechanism underlying their involvement is unknown. The aim of this study was to determine whether the CaCC ANO1 is involved in the pathogenesis of spontaneous hypertension. Arterial ANO1 expression and the effects on blood pressure (BP) of inhibiting ANO1 with an ANO1 inhibitor, T16(Ainh)-A01, and in vivo RNAi, were examined in spontaneously hypertensive rats (SHRs). Knockdown of ANO1 by siRNA prevented hypertensive development, and attenuation of ANO1 channel activity reduced BP in SHRs. Angiotensin II upregulated ANO1 expression in primary cultures of vascular smooth muscle cells (VSMCs). The protein level and activity of cellular ANO1 positively correlated with VSMC proliferation. Our data indicate an important role of increased ANO1 expression and activity in inducing hypertension in SHRs. It may mediate angiotensin II-dependent vascular remodeling. Our results increase the mechanistic understanding of hypertension and suggest ANO1 as a possible therapeutic target for hypertension.
Collapse
Affiliation(s)
- Bingxiang Wang
- Department of Physiology, Center for Medical Research, the First Affiliated Hospital, Medical College of Qingdao University, Qingdao 266071, China; Department of Physiology, Taishan Medical College, Taian 271000, China.
| | - Chunlin Li
- Department of Physiology, Center for Medical Research, the First Affiliated Hospital, Medical College of Qingdao University, Qingdao 266071, China.
| | - Ruituo Huai
- Robot Research Center, Shandong University of Science and Technology, Qingdao 266510, China.
| | - Zhiqiang Qu
- Department of Physiology, Center for Medical Research, the First Affiliated Hospital, Medical College of Qingdao University, Qingdao 266071, China.
| |
Collapse
|
6
|
Cherian OL, Menini A, Boccaccio A. Multiple effects of anthracene-9-carboxylic acid on the TMEM16B/anoctamin2 calcium-activated chloride channel. Biochim Biophys Acta 2015; 1848:1005-13. [PMID: 25620774 DOI: 10.1016/j.bbamem.2015.01.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Revised: 01/04/2015] [Accepted: 01/13/2015] [Indexed: 10/24/2022]
Abstract
Ca(2+)-activated Cl(-) currents (CaCCs) play important roles in many physiological processes. Recent studies have shown that TMEM16A/anoctamin1 and TMEM16B/anoctamin2 constitute CaCCs in several cell types. Here we have investigated for the first time the extracellular effects of the Cl(-) channel blocker anthracene-9-carboxylic acid (A9C) and of its non-charged analogue anthracene-9-methanol (A9M) on TMEM16B expressed in HEK 293T cells, using the whole-cell patch-clamp technique. A9C caused a voltage-dependent block of outward currents and inhibited a larger fraction of the current as depolarization increased, whereas the non-charged A9M produced a small, not voltage dependent block of outward currents. A similar voltage-dependent block by A9C was measured both when TMEM16B was activated by 1.5 and 13μM Ca(2+). However, in the presence of 1.5μM Ca(2+) (but not in 13μM Ca(2+)), A9C also induced a strong potentiation of tail currents measured at -100mV after depolarizing voltages, as well as a prolongation of the deactivation kinetics. On the contrary, A9M did not produce potentiation of tail currents, showing that the negative charge is required for potentiation. Our results provide the first evidence that A9C has multiple effects on TMEM16B and that the negative charge of A9C is necessary both for voltage-dependent block and for potentiation. Future studies are required to identify the molecular mechanisms underlying these complex effects of A9C on TMEM16B. Understanding these mechanisms will contribute to the elucidation of the structure and functional properties of TMEM16B channels.
Collapse
Affiliation(s)
- O Lijo Cherian
- Neurobiology Group, SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste, Italy
| | - Anna Menini
- Neurobiology Group, SISSA, International School for Advanced Studies, Via Bonomea 265, 34136 Trieste, Italy
| | - Anna Boccaccio
- Istituto di Biofisica, CNR, Via De Marini 6, 16149 Genova, Italy.
| |
Collapse
|
7
|
Abstract
Fluid and electrolyte releasing from secretory epithelia are elaborately regulated by orchestrated activity of ion channels. The activity of chloride channel at the apical membrane decides on the direction and the rate of secretory fluid and electrolyte. Chloride-dependent secretion is conventionally associated with intracellular increases in two second messengers, cAMP and Ca(2+), responding to luminal purinergic and basolateral adrenergic or cholinergic stimulation. While it is broadly regarded that cAMP-dependent Cl(-) secretion is regulated by cystic fibrosis transmembrane conductance regulator (CFTR), Ca(2+)-activated Cl(-) channel (CaCC) had been veiled for quite some time. Now, Anoctamin 1 (ANO1 or TMEM16A) confers Ca(2+)-activated Cl(-) currents. Ano 1 and its paralogs have been actively investigated for multiple functions underlying Ca(2+)-activated Cl(-) efflux and fluid secretion in a variety of secretory epithelial cells. In this review, we will discuss recent advances in the secretory function and signaling of ANO1 in the secretory epithelia, such as airways, intestines, and salivary glands.
Collapse
Affiliation(s)
- Yongwoo Jang
- Sensory Research Center, Creative Research Initiatives, College of Pharmacy, Seoul National University, Seoul, Republic of Korea
| | - Uhtaek Oh
- Sensory Research Center, Creative Research Initiatives, College of Pharmacy, Seoul National University, Seoul, Republic of Korea; Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Republic of Korea.
| |
Collapse
|
8
|
Ohshiro J, Yamamura H, Saeki T, Suzuki Y, Imaizumi Y. The multiple expression of Ca²⁺-activated Cl⁻ channels via homo- and hetero-dimer formation of TMEM16A splicing variants in murine portal vein. Biochem Biophys Res Commun 2014; 443:518-23. [PMID: 24321548 DOI: 10.1016/j.bbrc.2013.11.117] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 11/29/2013] [Indexed: 01/16/2023]
Abstract
Ca(2+)-activated Cl(-) channel (CaCC) often plays substantial roles in the regulation of membrane excitability in smooth muscle cells (SMCs). TMEM16A, a member of the TMEM16 family, has been suggested as the molecular entity responsible for CaCC in several types of SMCs. In this study, the expression of TMEM16A splicing variants and their contribution to CaCC activity were examined in murine portal vein SMCs (mPVSMCs). Four transcripts of TMEM16A splicing variants, which include four alternatively spliced segments ("a" and "b" in N-terminus and "c" and "d" in the first intracellular loop), were identified; the expression ratio of four transcripts of "abc", "acd", "abcd" and "ac" was 64.5, 25.8, 4.8 and 4.8%, respectively. The immunostaining of isolated mPVSMCs with anti-TMEM16A antibody indicates the abundant expression of TMEM16A on the cell membrane. CaCC currents recorded in mPVSMCs were markedly reduced by T16A(inh)-A01, a specific TMEM16A inhibitor. When the two major TMEM16A splicing variants, abc and acd isoforms, were expressed separately in HEK293 cells, the CaCC currents, which possess similar electrophysiological characteristics to those in mPVSMCs were observed. The single-molecule photobleaching analyses using total internal reflection fluorescence (TIRF) microscope indicated that the distribution of stepwise photobleaching events was fit well with a binomial distribution for homodimer. Additionally, the heterodimer formation was suggested by fluorescence resonance energy transfer (FRET) analyses in HEK293 cells co-expressing CFP- or YFP-tagged variants. In conclusion, alternatively spliced variants of TMEM16A abc and acd in mPVSMCs are two major molecular entities of CaCC and may form hetero-/homo-dimers to be functional as CaCC in the regulation of membrane excitability and contractility in mPVSMCs.
Collapse
|
9
|
Sondo E, Scudieri P, Tomati V, Caci E, Mazzone A, Farrugia G, Ravazzolo R, Galietta LJV. Non-canonical translation start sites in the TMEM16A chloride channel. Biochim Biophys Acta 2013; 1838:89-97. [PMID: 23994600 PMCID: PMC3898931 DOI: 10.1016/j.bbamem.2013.08.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 08/13/2013] [Accepted: 08/14/2013] [Indexed: 01/16/2023]
Abstract
TMEM16A is a plasma membrane protein with voltage- and calcium-dependent chloride channel activity. The role of the various TMEM16A domains in expression and function is poorly known. In a previous study, we found that replacing the first ATG of the TMEM16A coding sequence with a nonsense codon (M1X mutation), to force translation from the second ATG localized at position 117, only had minor functional consequences. Therefore, we concluded that this region is dispensable for TMEM16A processing and channel activity. We have now removed the first 116 codons from the TMEM16A coding sequence. Surprisingly, the expression of the resulting mutant, Δ(1–116), resulted in complete loss of activity. We hypothesized that, in the mutant M1X, translation may start at a position before the second ATG, using a non-canonical start codon. Therefore, we placed an HA-epitope at position 89 in the M1X mutant. We found, by western blot analysis, that the HA-epitope can be detected, thus demonstrating that translation starts from an upstream non-ATG codon. We truncated the N-terminus of TMEM16A at different sites while keeping the HA-epitope. We found that stepwise shortening of TMEM16A caused an in parallel stepwise decrease in TMEM16A expression and function. Our results indicate that indeed the N-terminus of TMEM16A is important for its activity. The use of an alternative start codon appears to occur in a naturally-occurring TMEM16A isoform that is particularly expressed in human testis. Future experiments will need to address the role of normal and alternative amino-terminus in TMEM16A structure and function. TMEM16A is a membrane protein with chloride channel activity. Two ATG codons are present at positions 1 and 117 of the TMEM16A coding sequence. Deletion of the first ATG, in contrast to removal of the first 116 codons, does not abolish TMEM16A function. Without the first ATG, TMEM16A translation begins from a non-canonical start codon.
Collapse
Affiliation(s)
- Elvira Sondo
- U.O.C. Genetica Medica, Istituto Giannina Gaslini, Genova, Italy
| | | | | | | | | | | | | | | |
Collapse
|