The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Makoto Tominaga - One of the best experts on this subject based on the ideXlab platform.
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trpv4 heats up ano1 dependent exocrine gland fluid secretion
The FASEB Journal, 2017Co-Authors: Sandra Derouiche, Yasunori Takayama, Masataka Murakami, Makoto TominagaAbstract:Several ion Channels and transporters regulate fluid secretion in salivary and lacrimal glands. In salivary glands, the major anion Channel involved in fluid secretion is the Calcium-Activated Chloride Channel anoctamin 1 (ANO1). Several members of the transient receptor potential (TRP) Channel superfamily regulate ANO1 activity. Here, we report a functional interaction between thermosensitive TRP vanilloid (TRPV)4 and ANO1 in acinar cells isolated from mouse salivary and lacrimal glands. TRPV4 activation induced Chloride currents and shrinkage of acinar cells by increasing intracellular calcium concentrations. The Chloride currents evoked by a TRPV4-specific activator (GSK1016790A) were identified as ANO1-mediated currents. Moreover, TRPV4 activation by an inositol 1,4,5-trisphosphate (IP3)-dependent mechanism was found to contribute to the muscarinic pathway of fluid secretion. Muscarinic stimulation of saliva and tear secretion was down-regulated in both TRPV4-deficient mice and in acinar cells treated...
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trpv4 heats up ano1 dependent exocrine gland fluid secretion
The FASEB Journal, 2017Co-Authors: Sandra Derouiche, Yasunori Takayama, Masataka Murakami, Makoto TominagaAbstract:Several ion Channels and transporters regulate fluid secretion in salivary and lacrimal glands. In salivary glands, the major anion Channel involved in fluid secretion is the Calcium-Activated Chloride Channel anoctamin 1 (ANO1). Several members of the transient receptor potential (TRP) Channel superfamily regulate ANO1 activity. Here, we report a functional interaction between thermosensitive TRP vanilloid (TRPV)4 and ANO1 in acinar cells isolated from mouse salivary and lacrimal glands. TRPV4 activation induced Chloride currents and shrinkage of acinar cells by increasing intracellular calcium concentrations. The Chloride currents evoked by a TRPV4-specific activator (GSK1016790A) were identified as ANO1-mediated currents. Moreover, TRPV4 activation by an inositol 1,4,5-trisphosphate (IP3)-dependent mechanism was found to contribute to the muscarinic pathway of fluid secretion. Muscarinic stimulation of saliva and tear secretion was down-regulated in both TRPV4-deficient mice and in acinar cells treated with a TRPV4-specific antagonist (HC-067047). Furthermore, the temperature dependence of muscarinic salivation was shown to depend mainly on TRPV4. Our results suggest that TRPV4 interacts with IP3 receptors and ANO1 to regulate the muscarinic pathway that mediates salivation and lacrimation.-Derouiche, S., Takayama, Y., Murakami, M., Tominaga, M. TRPV4 heats up ANO1-dependent exocrine gland fluid secretion.
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4 isopropylcyclohexanol has potential analgesic effects through the inhibition of anoctamin 1 trpv1 and trpa1 Channel activities
Scientific Reports, 2017Co-Authors: Yasunori Takayama, Makoto Tominaga, Hidemasa FurueAbstract:Interactions between Calcium-Activated Chloride Channel anoctamin 1 (ANO1) and transient receptor potential vanilloid 1 (TRPV1) enhance pain sensations in mice, suggesting that ANO1 inhibition could have analgesic effects. Here we show that menthol and the menthol analogue isopropylcyclohexane (iPr-CyH) inhibited ANO1 Channels in mice. The iPr-CyH derivative 4-isopropylcyclohexanol (4-iPr-CyH-OH) inhibited mouse ANO1 currents more potently than iPr-CyH. Moreover, 4-iPr-CyH-OH inhibited the activities of TRPV1, TRP ankyrin 1 (TRPA1), TRP melastatin 8 (TRPM8) and TRPV4. Single-Channel analysis revealed that 4-iPr-CyH-OH reduced TRPV1 and TRPA1 current open-times without affecting unitary amplitude or closed-time, suggesting that it affected gating rather than blocking the Channel pore. The ability of 4-iPr-CyH-OH to inhibit action potential generation and reduce pain-related behaviors induced by capsaicin in mice suggests that 4-iPr-CyH-OH could have analgesic applications. Thus, 4-iPr-CyH-OH is a promising base chemical to develop novel analgesics that target ANO1 and TRP Channels.
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pain enhancing mechanism through interaction between trpv1 and anoctamin 1 in sensory neurons
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Yasunori Takayama, Hidemasa Furue, Daisuke Uta, Makoto TominagaAbstract:The capsaicin receptor transient receptor potential cation Channel vanilloid 1 (TRPV1) is activated by various noxious stimuli, and the stimuli are converted into electrical signals in primary sensory neurons. It is believed that cation influx through TRPV1 causes depolarization, leading to the activation of voltage-gated sodium Channels, followed by the generation of action potential. Here we report that the capsaicin-evoked action potential could be induced by two components: a cation influx-mediated depolarization caused by TRPV1 activation and a subsequent anion efflux-mediated depolarization via activation of anoctamin 1 (ANO1), a Calcium-Activated Chloride Channel, resulting from the entry of calcium through TRPV1. The interaction between TRPV1 and ANO1 is based on their physical binding. Capsaicin activated the Chloride currents in an extracellular calcium-dependent manner in HEK293T cells expressing TRPV1 and ANO1. Similarly, in mouse dorsal root ganglion neurons, capsaicin-activated inward currents were inhibited significantly by a specific ANO1 antagonist, T16Ainh-A01 (A01), in the presence of a high concentration of EGTA but not in the presence of BAPTA [1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid]. The generation of a capsaicin-evoked action potential also was inhibited by A01. Furthermore, pain-related behaviors in mice treated with capsaicin, but not with αβ-methylene ATP, were reduced significantly by the concomitant administration of A01. These results indicate that TRPV1–ANO1 interaction is a significant pain-enhancing mechanism in the peripheral nervous system.
Yasunori Takayama - One of the best experts on this subject based on the ideXlab platform.
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trpv4 heats up ano1 dependent exocrine gland fluid secretion
The FASEB Journal, 2017Co-Authors: Sandra Derouiche, Yasunori Takayama, Masataka Murakami, Makoto TominagaAbstract:Several ion Channels and transporters regulate fluid secretion in salivary and lacrimal glands. In salivary glands, the major anion Channel involved in fluid secretion is the Calcium-Activated Chloride Channel anoctamin 1 (ANO1). Several members of the transient receptor potential (TRP) Channel superfamily regulate ANO1 activity. Here, we report a functional interaction between thermosensitive TRP vanilloid (TRPV)4 and ANO1 in acinar cells isolated from mouse salivary and lacrimal glands. TRPV4 activation induced Chloride currents and shrinkage of acinar cells by increasing intracellular calcium concentrations. The Chloride currents evoked by a TRPV4-specific activator (GSK1016790A) were identified as ANO1-mediated currents. Moreover, TRPV4 activation by an inositol 1,4,5-trisphosphate (IP3)-dependent mechanism was found to contribute to the muscarinic pathway of fluid secretion. Muscarinic stimulation of saliva and tear secretion was down-regulated in both TRPV4-deficient mice and in acinar cells treated...
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trpv4 heats up ano1 dependent exocrine gland fluid secretion
The FASEB Journal, 2017Co-Authors: Sandra Derouiche, Yasunori Takayama, Masataka Murakami, Makoto TominagaAbstract:Several ion Channels and transporters regulate fluid secretion in salivary and lacrimal glands. In salivary glands, the major anion Channel involved in fluid secretion is the Calcium-Activated Chloride Channel anoctamin 1 (ANO1). Several members of the transient receptor potential (TRP) Channel superfamily regulate ANO1 activity. Here, we report a functional interaction between thermosensitive TRP vanilloid (TRPV)4 and ANO1 in acinar cells isolated from mouse salivary and lacrimal glands. TRPV4 activation induced Chloride currents and shrinkage of acinar cells by increasing intracellular calcium concentrations. The Chloride currents evoked by a TRPV4-specific activator (GSK1016790A) were identified as ANO1-mediated currents. Moreover, TRPV4 activation by an inositol 1,4,5-trisphosphate (IP3)-dependent mechanism was found to contribute to the muscarinic pathway of fluid secretion. Muscarinic stimulation of saliva and tear secretion was down-regulated in both TRPV4-deficient mice and in acinar cells treated with a TRPV4-specific antagonist (HC-067047). Furthermore, the temperature dependence of muscarinic salivation was shown to depend mainly on TRPV4. Our results suggest that TRPV4 interacts with IP3 receptors and ANO1 to regulate the muscarinic pathway that mediates salivation and lacrimation.-Derouiche, S., Takayama, Y., Murakami, M., Tominaga, M. TRPV4 heats up ANO1-dependent exocrine gland fluid secretion.
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4 isopropylcyclohexanol has potential analgesic effects through the inhibition of anoctamin 1 trpv1 and trpa1 Channel activities
Scientific Reports, 2017Co-Authors: Yasunori Takayama, Makoto Tominaga, Hidemasa FurueAbstract:Interactions between Calcium-Activated Chloride Channel anoctamin 1 (ANO1) and transient receptor potential vanilloid 1 (TRPV1) enhance pain sensations in mice, suggesting that ANO1 inhibition could have analgesic effects. Here we show that menthol and the menthol analogue isopropylcyclohexane (iPr-CyH) inhibited ANO1 Channels in mice. The iPr-CyH derivative 4-isopropylcyclohexanol (4-iPr-CyH-OH) inhibited mouse ANO1 currents more potently than iPr-CyH. Moreover, 4-iPr-CyH-OH inhibited the activities of TRPV1, TRP ankyrin 1 (TRPA1), TRP melastatin 8 (TRPM8) and TRPV4. Single-Channel analysis revealed that 4-iPr-CyH-OH reduced TRPV1 and TRPA1 current open-times without affecting unitary amplitude or closed-time, suggesting that it affected gating rather than blocking the Channel pore. The ability of 4-iPr-CyH-OH to inhibit action potential generation and reduce pain-related behaviors induced by capsaicin in mice suggests that 4-iPr-CyH-OH could have analgesic applications. Thus, 4-iPr-CyH-OH is a promising base chemical to develop novel analgesics that target ANO1 and TRP Channels.
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pain enhancing mechanism through interaction between trpv1 and anoctamin 1 in sensory neurons
Proceedings of the National Academy of Sciences of the United States of America, 2015Co-Authors: Yasunori Takayama, Hidemasa Furue, Daisuke Uta, Makoto TominagaAbstract:The capsaicin receptor transient receptor potential cation Channel vanilloid 1 (TRPV1) is activated by various noxious stimuli, and the stimuli are converted into electrical signals in primary sensory neurons. It is believed that cation influx through TRPV1 causes depolarization, leading to the activation of voltage-gated sodium Channels, followed by the generation of action potential. Here we report that the capsaicin-evoked action potential could be induced by two components: a cation influx-mediated depolarization caused by TRPV1 activation and a subsequent anion efflux-mediated depolarization via activation of anoctamin 1 (ANO1), a Calcium-Activated Chloride Channel, resulting from the entry of calcium through TRPV1. The interaction between TRPV1 and ANO1 is based on their physical binding. Capsaicin activated the Chloride currents in an extracellular calcium-dependent manner in HEK293T cells expressing TRPV1 and ANO1. Similarly, in mouse dorsal root ganglion neurons, capsaicin-activated inward currents were inhibited significantly by a specific ANO1 antagonist, T16Ainh-A01 (A01), in the presence of a high concentration of EGTA but not in the presence of BAPTA [1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid]. The generation of a capsaicin-evoked action potential also was inhibited by A01. Furthermore, pain-related behaviors in mice treated with capsaicin, but not with αβ-methylene ATP, were reduced significantly by the concomitant administration of A01. These results indicate that TRPV1–ANO1 interaction is a significant pain-enhancing mechanism in the peripheral nervous system.
Wan Namkung - One of the best experts on this subject based on the ideXlab platform.
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ani9 a novel potent small molecule ano1 inhibitor with negligible effect on ano2
PLOS ONE, 2016Co-Authors: Yohan Seo, Jinhong Park, Ho K. Lee, Dong Kyu Jeon, Wan NamkungAbstract:Anoctamin1 (ANO1)/transmembrane protein 16A (TMEM16A), a Calcium-Activated Chloride Channel (CaCC), is involved in many physiological functions such as fluid secretion, smooth muscle contraction, nociception and cancer progression. To date, only a few ANO1 inhibitors have been described, and these have low potency and selectivity for ANO1. Here, we performed a high-throughput screening to identify highly potent and selective small molecule inhibitors of ANO1. Three novel ANO1 inhibitors were discovered from screening of 54,400 synthetic small molecules, and they were found to fully block ANO1 Channel activity with an IC50 < 3 μM. Electrophysiological analysis revealed that the most potent inhibitor, 2-(4-chloro-2-methylphenoxy)-N-[(2-methoxyphenyl)methylideneamino]-acetamide (Ani9), completely inhibited ANO1 Chloride current with submicromolar potency. Notably, unlike previous small-molecule ANO1 inhibitors identified to date, Ani9 displayed high selectivity for ANO1 as compared to ANO2, which shares a high amino acid homology to ANO1. In addition, Ani9 did not affect the intracellular calcium signaling and CFTR Chloride Channel activity. Our results suggest that Ani9 may be a useful pharmacological tool for studying ANO1 and a potential development candidate for drug therapy of cancer, hypertension, pain, diarrhea and asthma.
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inhibition of ano1 tmem16a Chloride Channel by idebenone and its cytotoxicity to cancer cell lines
PLOS ONE, 2015Co-Authors: Yohan Seo, Jinhong Park, Minseo Kim, Ho K. Lee, Jin Hee Kim, Jin Hyun Jeong, Wan NamkungAbstract:The expression levels of anoctamin 1 (ANO1, TMEM16A), a Calcium-Activated Chloride Channel (CaCC), are significantly increased in several tumors, and inhibition of ANO1 is known to reduce cell proliferation and migration. Here, we performed cell-based screening of a collection of natural products and drug-like compounds to identify inhibitors of ANO1. As a result of the screening, idebenone, miconazole and plumbagin were identified as novel ANO1 inhibitors. Electrophysiological studies showed that idebenone, a synthetic analog of coenzyme Q10, completely blocked ANO1 activity in FRT cells expressing ANO1 without any effect on intracellular calcium signaling and CFTR, a cAMP-regulated Chloride Channel. The CaCC activities in PC-3 and CFPAC-1 cells expressing abundant endogenous ANO1 were strongly blocked by idebenone. Idebenone inhibited cell proliferation and induced apoptosis in PC-3 and CFPAC-1 cells, but not in A549 cells, which do not express ANO1. These data suggest that idebenone, a novel ANO1 inhibitor, has potential for use in cancer therapy.
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small molecule activators of tmem16a a calcium activated Chloride Channel stimulate epithelial Chloride secretion and intestinal contraction
The FASEB Journal, 2011Co-Authors: Wan Namkung, Walter E FinkbeinerAbstract:TMEM16A (ANO1) is a Calcium-Activated Chloride Channel (CaCC) expressed in secretory epithelia, smooth muscle, and other tissues. Cell-based functional screening of ∼110,000 compounds revealed compounds that activated TMEM16A CaCC conductance without increasing cytoplasmic Ca2+. By patch-clamp, N-aroylaminothiazole “activators” (Eact) strongly increased Cl− current at 0 Ca2+, whereas tetrazolylbenzamide “potentiators” (Fact) were not active at 0 Ca2+ but reduced the EC50 for Ca2+-dependent TMEM16A activation. Of 682 analogs tested, the most potent activator (Eact) and potentiator (Fact) produced large and more sustained CaCC Cl− currents than general agonists of Ca2+ signaling, with EC50 3–6 μM and Cl− conductance comparable to that induced transiently by Ca2+-elevating purinergic agonists. Analogs of activators were identified that fully inhibited TMEM16A Cl− conductance, providing further evidence for direct TMEM16A binding. The TMEM16A activators increased CaCC conductance in human salivary and airway ...
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tmem16a inhibitors reveal tmem16a as a minor component of calcium activated Chloride Channel conductance in airway and intestinal epithelial cells
Journal of Biological Chemistry, 2011Co-Authors: Wan Namkung, Puay Wah Phuan, Alan S. VerkmanAbstract:Abstract TMEM16A (ANO1) functions as a Calcium-Activated Chloride Channel (CaCC). We developed pharmacological tools to investigate the contribution of TMEM16A to CaCC conductance in human airway and intestinal epithelial cells. A screen of ∼110,000 compounds revealed four novel chemical classes of small molecule TMEM16A inhibitors that fully blocked TMEM16A Chloride current with an IC50 < 10 μm, without interfering with calcium signaling. Following structure-activity analysis, the most potent inhibitor, an aminophenylthiazole (T16Ainh-A01), had an IC50 of ∼1 μm. Two distinct types of inhibitors were identified. Some compounds, such as tannic acid and the arylaminothiophene CaCCinh-A01, fully inhibited CaCC current in human bronchial and intestinal cells. Other compounds, including T16Ainh-A01 and digallic acid, inhibited total CaCC current in these cells poorly, but blocked mainly an initial, agonist-stimulated transient Chloride current. TMEM16A RNAi knockdown also inhibited mainly the transient Chloride current. In contrast to the airway and intestinal cells, all TMEM16A inhibitors fully blocked CaCC current in salivary gland cells. We conclude that TMEM16A carries nearly all CaCC current in salivary gland epithelium, but is a minor contributor to total CaCC current in airway and intestinal epithelia. The small molecule inhibitors identified here permit pharmacological dissection of TMEM16A/CaCC function and are potential development candidates for drug therapy of hypertension, pain, diarrhea, and excessive mucus production.
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small molecule screen identifies inhibitors of a human intestinal calcium activated Chloride Channel
Molecular Pharmacology, 2008Co-Authors: Ricardo De La Fuente, Aaron Mills, Wan Namkung, Alan S. VerkmanAbstract:Calcium-Activated Chloride Channels (CaCCs) are widely expressed in mammalian tissues, including intestinal epithelia, where they facilitate fluid secretion. Potent, selective CaCC inhibitors have not been available. We established a high-throughput screen for identification of inhibitors of a human intestinal CaCC based on inhibition of ATP/carbachol-stimulated iodide influx in HT-29 cells after lentiviral infection with the yellow fluorescent halide-sensing protein YFP-H148Q/I152L. Screening of 50,000 diverse, drug-like compounds yielded six classes of putative CaCC inhibitors, two of which, 3-acyl-2-aminothiophenes and 5-aryl-2-aminothiazoles, inhibited by >95% iodide influx in HT-29 cells in response to multiple calcium-elevating agonists, including thapsigargin, without inhibition of calcium elevation, calcium-calmodulin kinase II activation, or cystic fibrosis transmembrane conductance regulator Chloride Channels. These compounds also inhibited calcium-dependent Chloride secretion in T84 human intestinal epithelial cells. Patch-clamp analysis indicated inhibition of CaCC gating, which, together with the calcium-calmodulin data, suggests that the inhibitors target the CaCC directly. Structure-activity relationships were established from analysis of more than 1800 analogs, with IC50 values of the best analogs down to ∼1 μM. Small-molecule CaCC inhibitors may be useful in pharmacological dissection of CaCC functions and in reducing intestinal fluid losses in CaCC-mediated secretory diarrheas.
Qutayba Hamid - One of the best experts on this subject based on the ideXlab platform.
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increased expression of interleukin 9 interleukin 9 receptor and the calcium activated Chloride Channel hclca1 in the upper airways of patients with cystic fibrosis
Laryngoscope, 2003Co-Authors: Hans Peter Hauber, Roy C Levitt, John J Manoukian, Lily H P Nguyen, Steven E Sobol, Kenneth J Holroyd, Noel G Mcelvaney, Siobhan Griffin, Qutayba HamidAbstract:Objectives/Hypothesis Mucus overproduction is commonly found in airway disease in patients with cystic fibrosis. Interleukin-9 (IL-9) has been shown to mediate airway hyper-responsiveness and mucus overproduction. Recently, the Calcium-Activated Chloride Channel hCLCA1 has been described to be upregulated by IL-9 and has been thought to regulate the expression of soluble gel-forming mucins. We sought to examine the expression of IL-9, interleukin-9 receptor (IL-9R), and hCLCA1 in the upper airway of patients with cystic fibrosis in comparison to healthy control subjects and to demonstrate the relationship of IL-9, IL-9R, and hCLCA1 expression with mucus production. Study Design Prospective design. Methods Biopsy samples from nasal polyps of four patients with cystic fibrosis, nasal mucosa of six patients with cystic fibrosis, sinus mucosa of eight patients with cystic fibrosis, and nasal mucosa of six healthy control subjects were stained with periodic acid-Schiff (PAS) to identify mucus glycoconjugates. IL-9, IL-9R, and hCLCA1 expression was determined by immunocytochemical study. Results We demonstrated significant increases in IL-9, IL-9R, and hCLCA1 immunoreactivity in the mucosa of patients with cystic fibrosis compared with that found in control subjects (P .05). We also observed a significant increase in the number of mucus-producing cells in biopsy specimens from patients with cystic fibrosis in comparison to control subjects. A positive correlation was found between hCLCA1-positive cells and IL-9-positive cells (correlation coefficient [r] = 0.79, P <.05) or IL-9R-positive cells (r = 0.92, P <.05). Moreover, a positive correlation was also present between PAS-positive (mucus-producing) cells and hCLCA1-positive cells (r = 0.64, P <.05) or IL-9R-positive cells (r = 0.64, P <.05). Conclusions Increased expression of IL-9 and IL-9R, as well as upregulation of hCLCA1, in mucus-overproducing epithelium of patients with cystic fibrosis supports the hypothesis that IL-9 contributes to mucus overproduction in cystic fibrosis. Expression of hCLCA1 may also be responsible, in part, for the overproduction of mucus. These preliminary findings suggest that hCLCA1 might be an interesting new therapeutic target to control mucus overproduction in airway disease in patients with cystic fibrosis.
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a calcium activated Chloride Channel hclca1 is strongly related to il 9 expression and mucus production in bronchial epithelium of patients with asthma
The Journal of Allergy and Clinical Immunology, 2002Co-Authors: Masao Toda, Meri K Tulic, Roy C Levitt, Qutayba HamidAbstract:Abstract Background: One of the cardinal features of airway remodeling in asthma is mucus gland hyperplasia and mucus overproduction and hypersecretion. Recently, a Calcium-Activated Chloride Channel, HCLCA1 , was described that is upregulated by IL-9 and thought to regulate the expression of soluble gel-forming mucins, such as MUC5A/C, a critical component of mucus in the airways. Objective: We sought to examine the expression of HCLCA1 in bronchial biopsy specimens of asthmatic subjects compared with those of control subjects and to demonstrate its relationship with IL-9, IL-9 receptor (IL-9R), and markers of mucus production. Methods: Bronchial biopsy specimens from asthmatic (n = 9) and control (n = 10) subjects were stained with periodic acid-Schiff to identify mucus glycoconjugates. IL-9- and IL-9R-positive cells were identified with immunocytochemistry, and HCLCA1 expression was detected by means of in situ hybridization with cRNA probes. Results: We demonstrate significant increases in IL-9 ( P P HCLCA1 mRNA ( P P HCLCA1 mRNA was strongly and selectively colocalized with periodic acid-Schiff and IL-9R-positive epithelial cells. In particular, a strong positive correlation was observed between HCLCA1 mRNA expression and IL-9-positive ( r = 0.69, P r = 0.79, P Conclusion: An upregulation of HCLCA1 in the IL-9- responsive mucus-producing epithelium of asthmatic subjects compared with that seen in control subjects supports the hypothesis that this Channel may be responsible, in part, for the overproduction of mucus in asthmatic subjects. These preliminary findings suggest the inhibition of HCLCA1 may be an important new therapeutic approach to control mucus overproduction in chronic airway disorders. (J Allergy Clin Immunol 2002;109:246-50.)
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a calcium activated Chloride Channel hclca1 is strongly related to il 9 expression and mucus production in bronchial epithelium of patients with asthma
The Journal of Allergy and Clinical Immunology, 2002Co-Authors: Masao Toda, Meri K Tulic, Roy C Levitt, Qutayba HamidAbstract:BACKGROUND: One of the cardinal features of airway remodeling in asthma is mucus gland hyperplasia and mucus overproduction and hypersecretion. Recently, a Calcium-Activated Chloride Channel, HCLCA1, was described that is upregulated by IL-9 and thought to regulate the expression of soluble gel-forming mucins, such as MUC5A/C, a critical component of mucus in the airways. OBJECTIVE: We sought to examine the expression of HCLCA1 in bronchial biopsy specimens of asthmatic subjects compared with those of control subjects and to demonstrate its relationship with IL-9, IL-9 receptor (IL-9R), and markers of mucus production. METHODS: Bronchial biopsy specimens from asthmatic (n = 9) and control (n = 10) subjects were stained with periodic acid-Schiff to identify mucus glycoconjugates. IL-9- and IL-9R-positive cells were identified with immunocytochemistry, and HCLCA1 expression was detected by means of in situ hybridization with cRNA probes. RESULTS: We demonstrate significant increases in IL-9 (P <.001) and IL-9R (P <.05) immunoreactivity, as well as increased expression of HCLCA1 mRNA (P <.001), in the epithelium of asthmatic patients compared with that found in control subjects. There was also an increase in the number of mucusproducing cells in biopsy specimens from asthmatic subjects (P <.001). HCLCA1 mRNA was strongly and selectively colocalized with periodic acid-Schiff and IL-9R-positive epithelial cells. In particular, a strong positive correlation was observed between HCLCA1 mRNA expression and IL-9-positive (r = 0.69, P < 0.01) or IL9R-positive (r = 0.79, P <.01) cells. CONCLUSION: An upregulation of HCLCA1 in the IL-9- responsive mucus-producing epithelium of asthmatic subjects compared with that seen in control subjects supports the hypothesis that this Channel may be responsible, in part, for the overproduction of mucus in asthmatic subjects. These preliminary findings suggest the inhibition of HCLCA1 may be an important new therapeutic approach to control mucus overproduction in chronic airway disorders.
Charles W Emala - One of the best experts on this subject based on the ideXlab platform.
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agonism of the tmem16a calcium activated Chloride Channel modulates airway smooth muscle tone
American Journal of Physiology-lung Cellular and Molecular Physiology, 2020Co-Authors: Jennifer Danielsson, George Gallos, Aisha S Kuforiji, Gene T Yocum, Yi Zhang, Dingbang Xu, Charles W EmalaAbstract:TMEM16A (anoctamin 1) is an important Calcium-Activated Chloride Channel in airway smooth muscle (ASM). We have previously shown that TMEM16A antagonists such as benzbromarone relax ASM and have pr...
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antagonists of the tmem16a calcium activated Chloride Channel modulate airway smooth muscle tone and intracellular calcium
Anesthesiology, 2015Co-Authors: Jennifer Danielsson, George Gallos, Yi Zhang, Jose F Perezzoghbi, Kyra Bernstein, Matthew B Barajas, Satish Kumar, Pawan Sharma, Charles W EmalaAbstract:BACKGROUND: Perioperative bronchospasm refractory to β agonists continues to challenge anesthesiologists and intensivists. The TMEM16A Calcium-Activated Chloride Channel modulates airway smooth muscle (ASM) contraction. The authors hypothesized that TMEM16A antagonists would relax ASM contraction by modulating membrane potential and calcium flux. METHODS: Human ASM, guinea pig tracheal rings, or mouse peripheral airways were contracted with acetylcholine or leukotriene D4 and then treated with the TMEM16A antagonists: benzbromarone, T16Ainh-A01, N-((4-methoxy)-2-naphthyl)-5-nitroanthranilic acid, or B25. In separate studies, guinea pig tracheal rings were contracted with acetylcholine and then exposed to increasing concentrations of isoproterenol (0.01 nM to 10 μM) ± benzbromarone. Plasma membrane potential and intracellular calcium concentrations were measured in human ASM cells. RESULTS: Benzbromarone was the most potent TMEM16A antagonist tested for relaxing an acetylcholine -induced contraction in guinea pig tracheal rings (n = 6). Further studies were carried out to investigate the clinical utility of benzbromarone. In human ASM, benzbromarone relaxed either an acetylcholine- or a leukotriene D4-induced contraction (n = 8). Benzbromarone was also effective in relaxing peripheral airways (n = 9) and potentiating relaxation by β agonists (n = 5 to 10). In cellular mechanistic studies, benzbromarone hyperpolarized human ASM cells (n = 9 to 12) and attenuated intracellular calcium flux from both the plasma membrane and the sarcoplasmic reticulum (n = 6 to 12). CONCLUSION: TMEM16A antagonists work synergistically with β agonists and through a novel pathway of interrupting ion flux at both the plasma membrane and sarcoplasmic reticulum to acutely relax human ASM.
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functional expression of the tmem16 family of calcium activated Chloride Channels in airway smooth muscle
American Journal of Physiology-lung Cellular and Molecular Physiology, 2013Co-Authors: George Gallos, Jennifer Danielsson, Kenneth E Remy, Hiromi Funayama, Herngyu Sucie Chang, Peter D Yim, Charles W EmalaAbstract:Airway smooth muscle hyperresponsiveness is a key component in the pathophysiology of asthma. Although Calcium-Activated Chloride Channel (CaCC) flux has been described in many cell types, including human airway smooth muscle (HASM), the true molecular identity of the Channels responsible for this Chloride conductance remains controversial. Recently, a new family of proteins thought to represent the true CaCCs was identified as the TMEM16 family. This led us to question whether members of this family are functionally expressed in native and cultured HASM. We further questioned whether expression of these Channels contributes to the contractile function of HASM. We identified the mRNA expression of eight members of the TMEM16 family in HASM cells and show immunohistochemical evidence of TMEM16A in both cultured and native HASM. Functionally, we demonstrate that the classic Chloride Channel inhibitor, 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB), inhibited halide flux in cultured HASM cells. Moreover, HASM cells displayed classical electrophysiological properties of CaCCs during whole cell electrophysiological recordings, which were blocked by using an antibody selective for TMEM16A. Furthermore, two distinct TMEM16A antagonists (tannic acid and benzbromarone) impaired a substance P-induced contraction in isolated guinea pig tracheal rings. These findings demonstrate that multiple members of this recently described family of CaCCs are expressed in HASM cells, they display classic electrophysiological properties of CaCCs, and they modulate contractile tone in airway smooth muscle. The TMEM16 family may provide a novel therapeutic target for limiting airway constriction in asthma.
