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Huang YP, Huang WW, Tsai KF, Shiao LR, Yang ZH, Tseng SY, Lin YH, Chen CY, Chan P, Leung YM. CDN1163, a SERCA activator, causes intracellular Ca 2+ leak, mitochondrial hyperpolarization and cell cycle arrest in mouse neuronal N2A cells. Neurotoxicology 2023; 98:9-15. [PMID: 37429421 DOI: 10.1016/j.neuro.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 03/05/2023] [Revised: 06/11/2023] [Accepted: 07/07/2023] [Indexed: 07/12/2023]
Abstract
OBJECTIVE Activity or expression of sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA) is diminished in some disease states such as cardiac failure and diabetes mellitus. A newly developed activator of SERCA, CDN1163, reportedly rescued or alleviated pathological conditions attributed to dysfunctional SERCA. We examined whether CDN1163 could relieve mouse neuronal N2A cell growth inhibition caused by cyclopiazonic acid (CPA, SERCA inhibitor). We also examined how CDN1163 affected cytosolic Ca2+, mitochondrial Ca2+ and mitochondrial membrane potential. METHODS Cell viability was measured by MTT assay and trypan blue exclusion test. Cytosolic Ca2+, mitochondrial Ca2+ and mitochondrial membrane potential were measured using fura 2, Rhod-2 and JC-1, respectively, as fluorescent probes. RESULTS CDN1163 (10 μM) itself suppressed cell proliferation, and did not alleviate CPA's inhibitory effect (and vice versa). Cell cycle was arrested at the G1 phase after CDN1163 treatment. CDN1163 treatment caused a slow yet persistent cytosolic [Ca2+] elevation partly due to Ca2+ release from an internal store other than the CPA-sensitive endoplasmic reticulum (ER). Treatment with CDN1163 for 3 h raised mitochondrial Ca2+ level and such increase was suppressed by MCU-i4 (an inhibitor of mitochondria Ca2+ uniporter, MCU), suggesting Ca2+ entered the mitochondrial matrix through MCU. Treatment of cells with CDN1163 up to 2 days resulted in mitochondrial hyperpolarization. CONCLUSION CDN1163 caused internal Ca2+ leak, cytosolic Ca2+ overload, mitochondrial Ca2+ elevation and hyperpolarization, cell cycle arrest and cell growth inhibition.
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Affiliation(s)
- Yi-Ping Huang
- Department of Physiology, China Medical University, Taichung 40402, Taiwan
| | - Wen-Wei Huang
- Department of Internal Medicine, Gastroenterology and Hepatology Section, An Nan Hospital, China Medical University, Tainan, Taiwan
| | - Kun-Feng Tsai
- Department of Internal Medicine, Gastroenterology and Hepatology Section, An Nan Hospital, China Medical University, Tainan, Taiwan; Department of Medical Sciences Industry, Chang Jung Christian University, Tainan, Taiwan
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, Taichung 40402, Taiwan
| | - Zih-He Yang
- Department of Physiology, China Medical University, Taichung 40402, Taiwan
| | - Shao-Yun Tseng
- Department of Physiology, China Medical University, Taichung 40402, Taiwan
| | - Yu-Hsien Lin
- Department of Physiology, China Medical University, Taichung 40402, Taiwan
| | - Cing-Yu Chen
- Department of Cosmetic Science, Providence University, Taichung, Taiwan; School of Pharmacy, China Medical University, Taichung, Taiwan
| | - Paul Chan
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung 40402, Taiwan.
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Tsai TY, Chen CY, Shiao LR, Ou TT, Wu CH, Leung YM, Chow LWC. Afatinib triggers a Ni 2+ -resistant Ca 2+ influx pathway in A549 non-small cell lung cancer cells. Fundam Clin Pharmacol 2023; 37:253-262. [PMID: 36191338 DOI: 10.1111/fcp.12835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 06/14/2022] [Revised: 09/09/2022] [Accepted: 10/02/2022] [Indexed: 03/04/2023]
Abstract
Afatinib is used to treat non-small cell lung cancer cells (NSCLC), and its mechanism involves irreversible inhibition of epidermal growth factor receptor (EGFR) tyrosine kinase. In this study, we examined if afatinib had cytotoxic action against NSCLC other than inhibition of tyrosine kinase. Afatinib (1-30 μM) caused apoptotic death in A549 NSCLC in a concentration-dependent manner. Afatinib triggered Ca2+ influx without causing Ca2+ release, and the Ca2+ influx was unaffected by sodium orthovanadate (SOV, an inhibitor of tyrosine phosphatase), suggesting that afatinib-triggered Ca2+ response was unrelated to its inhibition of tyrosine kinase. Addition of afatinib also promoted Mn2+ influx. Ca2+ influx triggered by afatinib was resistant to SKF96365 and ruthenium red (two general blockers of TRP channels) and, unexpectedly, Ni2+ (a non-specific Ca2+ channel blocker). Afatinib caused an increase in mitochondrial Ca2+ level, an initial mitochondrial hyperpolarization (4 h) and followed by mitochondrial potential collapse (24-48 h). Afatinib-induced cell death was slightly but significantly alleviated in low extracellular Ca2+ condition or under pharmacological block of mitochondrial permeability transition pore (MPTP) opening by cyclosporin A. Therefore, in addition to tyrosine kinase inhibition as a major anti-cancer mechanism of afatinib, stimulation of an atypical Ca2+ influx pathway, mitochondrial Ca2+ overload, and potential collapse in part contribute to afatinib-induced cell death.
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Affiliation(s)
- Tien-Yao Tsai
- Cardiovascular Division, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei City, Taiwan
| | - Cing-Yu Chen
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Ting-Tsz Ou
- Department of Medicinal Botanicals and Healthcare, Dayeh University, Changhua, Taiwan
| | - Cheng-Hsun Wu
- Department of Anatomy, China Medical University, Taichung, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Louis W C Chow
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau.,UNIMED Medical Institute, Hong Kong.,Organisation for Oncology and Translational Research, Hong Kong
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Leong IL, Yu CM, Shiao LR, Chan P, Wu KC, Leung YM. Sensitivity of Ca 2+-sensing receptor-transient receptor potential-mediated Ca 2+ influx to extracellular acidity in bEND.3 endothelial cells. CHINESE J PHYSIOL 2022; 65:277-281. [PMID: 36588353 DOI: 10.4103/0304-4920.365460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Ca2+-sensing receptors (CaSRs) are G protein-coupled receptors activated by elevated concentrations of extracellular Ca2+. In our previous works, we showed protein and functional expression of CaSR in mouse cerebral endothelial cell (EC) (bEND.3); the CaSR response (high Ca2+-elicited cytosolic [Ca2+] elevation) was unaffected by suppression of phospholipase C but in part involved Ca2+ influx through transient receptor potential V1 (TRPV1) channels. In this work, we investigated if extracellular acidity affected CaSR-mediated Ca2+ influx triggered by high (3 mM) Ca2+ (CaSR agonist), 3 mM spermine (CaSR agonist), and 10 mM cinacalcet (positive allosteric modulator of CaSR). Extracellular acidosis (pH 6.8 and pH 6.0) strongly suppressed cytosolic [Ca2+] elevation triggered by high Ca2+, spermine, and cinacalcet; acidosis also inhibited Mn2+ influx stimulated by high Ca2+ and cinacalcet. Purinoceptor-triggered Ca2+ response, however, was not suppressed by acidosis. Extracellular acidity also did not affect membrane potential, suggesting suppressed CaSR-mediated Ca2+ influx in acidity did not result from the reduced electrical driving force for Ca2+. Our results suggest Ca2+ influx through a putative CaSR-TRP complex in bEND.3 EC was sensitive to extracellular pH.
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Affiliation(s)
- Iat-Lon Leong
- Division of Cardiology, Department of Internal Medicine, Kiang Wu Hospital, Macau, China
| | - Chung-Ming Yu
- Department of Anesthesiology, Chang Gung Memorial Hospital, Chiayi, Taiwan
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Taipei Medical University Wan Fang Hospital, Taipei, Taiwan
| | - King-Chuen Wu
- Department of Anesthesiology, Chang Gung Memorial Hospital, Chiayi; Department of Nursing, Chang Gung University of Science and Technology, Chiayi; Department of Information Management, Shu-Zen Junior College of Medicine and Management, Kaohsiung, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, Taiwan
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Chuang CM, Chen CY, Yen PS, Wu CH, Shiao LR, Wong KL, Chan P, Leung YM. Propofol Causes Sustained Ca2+ Elevation in Endothelial Cells by Stimulating Ryanodine Receptor and Suppressing Plasmalemmal Ca2+ Pump. J Cardiovasc Pharmacol 2022; 79:749-757. [PMID: 35239284 DOI: 10.1097/fjc.0000000000001246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 01/23/2022] [Indexed: 11/25/2022]
Abstract
ABSTRACT Propofol, a general anesthetic administered intravenously, may cause pain at the injection site. The pain is in part due to irritation of vascular endothelial cells. We here investigated the effects of propofol on Ca2+ transport and pain mediator release in human umbilical vein endothelial cells (EA.hy926). Propofol mobilized Ca2+ from cyclopiazonic acid (CPA)-dischargeable pool but did not cause Ca2+ release from the lysosomal Ca2+ stores. Propofol-elicited Ca2+ release was suppressed by 100 μM ryanodine, suggesting the participation of ryanodine receptor channels. Propofol did not affect ATP-triggered Ca2+ release but abolished the Ca2+ influx triggered by ATP; in addition, propofol also suppressed store-operated Ca2+ entry elicited by CPA. Ca2+ clearance during CPA-induced Ca2+ discharge was unaffected by a low Na+ (50 mM) extracellular solution, but strongly suppressed by 5 mM La3+ (an inhibitor of plasmalemmal Ca2+ pump), suggesting Ca2+ extrusion was predominantly through the plasmalemmal Ca2+ pump. Propofol mimicked the effect of La3+ in suppressing Ca2+ clearance. Propofol also stimulated release of pain mediators, namely, reactive oxygen species and bradykinin. Our data suggest propofol elicited Ca2+ release and repressed Ca2+ clearance, causing a sustained cytosolic [Ca2+]i elevation. The latter may cause reactive oxygen species and bradykinin release, resulting in pain.
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Affiliation(s)
- Chin-Min Chuang
- Department of Emergency Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Cing-Yu Chen
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Pao-Sheng Yen
- Department of Radiology, Kuang Tien General Hospital, Shalu, Taichung, Taiwan
| | - Cheng-Hsun Wu
- Department of Anatomy, China Medical University, Taichung, Taiwan
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Kar-Lok Wong
- Department of Anesthesiology, Kuang Tien General Hospital, Shalu, Taichung, Taiwan
- Department of Anesthesiology, University of Hong Kong, Hong Kong, China; and
| | - Paul Chan
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, Taiwan
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Ou TT, Chuang CM, Leung YM, Lee IT, Wu CH. Paeoniflorin attenuates oxidative stress injury and improves mitochondrial membrane potential in human EA.hy926 endothelial cell through p-eIF2α and CHOP signaling. J Funct Foods 2021. [DOI: 10.1016/j.jff.2021.104676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Tsai KF, Shen CJ, Cheung CW, Wang TL, Chow LWC, Leung YM, Wong KL. Lipotoxicity in human lung alveolar type 2 A549 cells: Mechanisms and protection by tannic acid. CHINESE J PHYSIOL 2021; 64:289-297. [PMID: 34975122 DOI: 10.4103/cjp.cjp_68_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Palmitic acid (PA) is a saturated free fatty acid which, when being excessive, accounts for lipotoxicity. Using human lung A549 cells as a model for lung alveolar type 2 epithelial cells, we found that challenge of A549 cells with PA resulted in apoptotic cell death, as reflected by positive annexin V and PI staining, and also appearance of cleaved caspase-3. PA treatment also caused depletion of intracellular Ca2+ store, endoplasmic reticulum (ER) stress, and oxidative stress. Tannic acid (TA), a polyphenol present in wines and many beverages, alleviated PA-induced ER stress, oxidative stress and apoptotic death. Thus, our results suggest PA lipotoxicity in lung alveolar type 2 epithelial cells could be protected by TA.
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Affiliation(s)
- Kun-Feng Tsai
- Gastroenterology and Hepatology Section, Department of Internal Medicine, An Nan Hospital, China Medical University; Department of Medical Sciences Industry, Chang Jung Christian University, Tainan, Taiwan
| | - Chen-Jung Shen
- Endocrinology and Metabolism Section, Department of Internal Medicine, An Nan Hospital, China Medical University, Tainan, Taiwan
| | - Chi-Wai Cheung
- Department of Anesthesiology, University of Hong Kong, China
| | - Tzong-Luen Wang
- School of Medicine, Fu-Jen Catholic University; Department of Emergency Medicine, Fu-Jen Catholic University Hospital, Taipei, Taiwan
| | - Louis W C Chow
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau; UNIMED Medical Institute, Hong Kong; Organisation for Oncology and Translational Research, Hong Kong, China
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Kar-Lok Wong
- Department of Anesthesiology, University of Hong Kong, China; Department of Anesthesiology, Kuang Tien General Hospital, Shalu, Taichung, Taiwan
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Chen CY, Wu CH, Wu KC, Shiao LR, Chuang CM, Leung YM, Chow LWC. A basal level of γ-linolenic acid depletes Ca 2+ stores and induces endoplasmic reticulum and oxidative stresses to cause death of breast cancer BT-474 cells. CHINESE J PHYSIOL 2021; 64:202-209. [PMID: 34472451 DOI: 10.4103/cjp.cjp_30_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Gamma-linolenic acid (GLA), a natural fatty acid obtained from oils of various vegetables and seeds, has been demonstrated as an anticancer agent. In this work, we investigated the anticancer effects of GLA on breast cancer BT-474 cells. GLA at 30 μM, a concentration reportedly within the range of circulating concentrations in clinical studies, caused apoptotic cell death. GLA caused an elevation in mitochondrial Ca2+ level and a decrease in mitochondrial membrane potential. GLA treatment depleted cyclopiazonic acid (CPA)-sensitive Ca2+ store and triggered substantial Ca2+ influx. Intracellular Ca2+ release triggered by GLA was suppressed by 3 μM xestospongin C (XeC, IP3 receptor-channel blocker) and 100 μM ryanodine (ryanodine receptor-channel blocker), suggesting that the Ca2+ release was via IP3 receptor-channel and ryanodine receptor-channel. Increased expressions of p-eIF2α and CHOP were observed in GLA-treated cells, suggesting GLA-treated cells had increased expressions of p-eIF2α and CHOP, which suggest endoplasmic reticulum (ER) stress. In addition, GLA elicited increased production of reactive oxygen species. Taken together, our results suggest a basal level of GLA induced apoptotic cell death by causing Ca2+ overload, mitochondrial dysfunction, Ca2+ store depletion, ER stress, and oxidative stress. This is the first report to show that GLA caused Ca2+ store depletion and ER stress. GLA-induced Ca2+ store depletion resulted from opening of IP3 receptor-channel and ryanodine receptor-channel.
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Affiliation(s)
- Cing-Yu Chen
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Cheng-Hsun Wu
- Department of Anatomy, China Medical University, Taichung, Taiwan
| | - King-Chuen Wu
- Department of Anesthesiology, Chang Gung Memorial Hospital; Chang Gung University of Science and Technology, Chiayi, Taiwan
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Chin-Min Chuang
- Department of Emergency Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Louis W C Chow
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau; UNIMED Medical Institute; Organisation for Oncology and Translational Research, Hong Kong, China
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Leong IL, Tsai TY, Shiao LR, Zhang YM, Wong KL, Chan P, Leung YM. Characterization of Ca 2+-Sensing Receptor-Mediated Ca 2+ Influx in Microvascular bEND.3 Endothelial Cells. CHINESE J PHYSIOL 2021; 64:80-87. [PMID: 33938818 DOI: 10.4103/cjp.cjp_93_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Ca2+-sensing receptors (CaSR), activated by elevated concentrations of extracellular Ca2+, have been known to regulate functions of thyroid cells, neurons, and endothelial cells (EC). In this report, we studied CaSR-mediated Ca2+ influx in mouse cerebral microvascular EC (bEND.3 cells). Cytosolic free Ca2+ concentration and Mn2+ influx were measured by fura-2 microfluorometry. High (3 mM) Ca2+ (CaSR agonist), 3 mM spermine (CaSR agonist), and 10 μM cinacalcet (positive allosteric modulator of CaSR) all triggered Ca2+ influx; however, spermine, unlike high Ca2+ and cinacalcet, did not promote Mn2+ influx and its response was poorly sensitive to SKF 96365, a TRP channel blocker. Consistently, 2-aminoethoxydiphenyl borate and ruthenium red (two other general TRP channel blockers) suppressed Ca2+ influx triggered by cinacalcet and high Ca2+ but not by spermine. Ca2+ influx triggered by high Ca2+, spermine, and cinacalcet was similarly suppressed by A784168, a potent and selective TRPV1 antagonist. Our results suggest that CaSR activation triggered Ca2+ influx via TRPV1 channels; intriguingly, pharmacological, and permeability properties of such Ca2+ influx depended on the stimulating ligands.
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Affiliation(s)
- Iat-Lon Leong
- Department of Internal Medicine, Division of Cardiology, Kiang Wu Hospital, Macau, China
| | - Tien-Yao Tsai
- Cardiovascular Division, Fu Jen Catholic University Hospital, Fu Jen Catholic University, New Taipei City; Department of Cardiology, Lotung Poh-Ai Hospital, Yilan County, Taiwan
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Yu-Mei Zhang
- VIP Department, East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Kar-Lok Wong
- Department of Anesthesiology, China Medical University Hospital; Department of Anesthesiology, Kuang Tien General Hospital, Taichung, Taiwan
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, Taiwan
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Wu KC, Wong KL, Shiao LR, Chen CY, Chan P, Leung YM. Perturbation of Ca 2+ stores and store-operated Ca 2+ influx by lidocaine in neuronal N2A and NG108-15 cells. Eur J Pharmacol 2021; 904:174115. [PMID: 33901459 DOI: 10.1016/j.ejphar.2021.174115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 11/10/2020] [Revised: 04/13/2021] [Accepted: 04/20/2021] [Indexed: 10/21/2022]
Abstract
In this report we examined the effects of lidocaine on Ca2+ homeostasis of neuronal cells using microfluorimetric measurement of cytosolic Ca2+ with fura 2 as probe. In mouse neuroblastoma N2A cells, 10 mM lidocaine caused Ca2+ release from the cyclopiazonic acid (CPA)-dischargeable pool and abolished ATP-triggered Ca2+ release. Lidocaine-triggered Ca2+ release was not affected by xestospongin C (XeC), an inositol 1,4,5-trisphosphate receptor (IP3R) inhibitor. N2A cells did not have functional ryanodine receptors (RYR) (absence of caffeine response) and we used differentiated NG108-15 cells (presence of caffeine response) for further experiments. Caffeine-triggered Ca2+ release was unaffected by a brief lidocaine exposure, but was eliminated after a prolonged treatment of lidocaine, suggesting lidocaine abolished caffeine action possibly not by interfering caffeine binding but via Ca2+ store depletion. Lidocaine-elicited Ca2+ release was unaffected by XeC or a high concentration of ryanodine, suggesting Ca2+ release was not via IP3R or RYR. Lidocaine did not affect nigericin-dischargeable lysosomal Ca2+ stores. Lastly, we observed that lidocaine suppressed CPA-induced store-operated Ca2+ influx in both N2A cells and differentiated NG108-15 cells. Our results suggest two novel actions of lidocaine in neuronal cells, namely, depletion of Ca2+ store (via an IP3R- and RYR-independent manner) and suppression of store-operated Ca2+ influx.
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Affiliation(s)
- King-Chuen Wu
- Department of Anesthesiology, Chang Gung Memorial Hospital, Chiayi, Taiwan; Chang Gung University of Science and Technology, Chiayi, Taiwan
| | - Kar-Lok Wong
- Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan; Department of Anesthesiology, Kuang Tien General Hospital, Shalu, Taichung, Taiwan
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, Taichung, 40402, Taiwan
| | - Cing-Yu Chen
- Department of Physiology, China Medical University, Taichung, 40402, Taiwan
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Taipei Medical University Wan Fang, Hospital, Taipei, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, 40402, Taiwan.
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Tsai TY, Leong IL, Shiao LR, Wong KL, Shao L, Chan P, Leung YM. Tannic acid, a vasodilator present in wines and beverages, stimulates Ca2+ influx via TRP channels in bEND.3 endothelial cells. Biochem Biophys Res Commun 2020; 526:117-121. [DOI: 10.1016/j.bbrc.2020.03.078] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 03/13/2020] [Indexed: 10/24/2022]
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Chow LWC, Wong KL, Shiao LR, Wu KC, Leung YM. Polyamine stimulation perturbs intracellular Ca2+ homeostasis and decreases viability of breast cancer BT474 cells. ACTA ACUST UNITED AC 2020; 75:65-73. [PMID: 32092040 DOI: 10.1515/znc-2019-0119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 06/23/2019] [Accepted: 01/21/2020] [Indexed: 11/15/2022]
Abstract
Intracellular polyamines such as spermine and spermidine are essential to cell growth in normal and especially in cancer cells. However, whether extracellular polyamines affect cancer cell survival is unknown. We therefore examined the actions of extracellular polyamines on breast cancer BT474 cells. Our data showed that spermine, spermidine, and putrescine decreased cell viability by apoptosis. These polyamines also elicited Ca2+ signals, but the latter were unlikely triggered via Ca2+-sensing receptor (CaSR) as BT474 cells have been demonstrated previously to lack CaSR expression. Spermine-elicited Ca2+ response composed of both Ca2+ release and Ca2+ influx. Spermine caused a complete discharge of the cyclopiazonic acid (CPA)-sensitive Ca2+ pool and, expectedly, endoplasmic reticulum (ER) stress. The Ca2+ influx pore opened by spermine was Mn2+-impermeable, distinct from the CPA-triggered store-operated Ca2+ channel, which was Mn2+-permeable. Spermine cytotoxic effects were not due to oxidative stress, as spermine did not trigger reactive oxygen species formation. Our results therefore suggest that spermine acted on a putative polyamine receptor in BT474 cells, causing cytotoxicity by Ca2+ overload, Ca2+ store depletion, and ER stress.
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Affiliation(s)
- Louis W C Chow
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau, China.,UNIMED Medical Institute, 8/F Club Lusitano, 16 Ice House Street, Hong Kong, China.,Organisation for Oncology and Translational Research, Unit A, 9/F, CNT Commercial Building, 302 Queen's Road Central, Hong Kong, China
| | - Kar-Lok Wong
- Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, Taichung 40402, Taiwan
| | - King-Chuen Wu
- Department of Anesthesiology, Chang Gung Memorial Hospital, No. 6, Sec. West, Jiapu Rd., Puzi City, Chiayi County 61363, Taiwan.,Chang Gung University of Science and Technology, No. 2, Sec. West, Jiapu Rd., Puzi City, Chiayi County 61363, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung 40402, Taiwan, Phone: +886-04-2205336 ext. 2185
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Chen CY, Hour MJ, Shiao LR, Wong KL, Leung YM, Chan P, So EC. Quercetin depletes intracellular Ca 2+ stores and blunts ATP-triggered Ca 2+ signaling in bEnd.3 endothelial cells. Fundam Clin Pharmacol 2019; 34:213-221. [PMID: 31618480 DOI: 10.1111/fcp.12514] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 09/11/2019] [Accepted: 10/14/2019] [Indexed: 12/21/2022]
Abstract
Quercetin is a flavonol polyphenol widely found in many vegetables, grains, and fruits. Quercetin has been shown to inhibit proliferation and invasion of various glioma cells and is regarded as a potential anticancer agent against glioma. However, whether and how this drug could affect brain blood vessels and endothelial cells (EC) are less understood. Further, there is hitherto no report on how quercetin affects brain EC Ca2+ homeostasis. In this report, we investigated the effects of quercetin on Ca2+ homeostasis in mouse brain bEnd.3 EC. We demonstrated that quercetin raised cytosolic Ca2+ level in a concentration-dependent manner. Quercetin-triggered Ca2+ signal composed of both internal Ca2+ release and extracellular Ca2+ influx. Quercetin caused Ca2+ release from the endoplasmic reticulum, and consistently, inhibition of inositol 1,4,5-trisphosphate receptor (IP3R) by xestospongin C (XeC) suppressed quercetin-triggered Ca2+ release. Quercetin also caused Ca2+ release from lysosomes, an observation in concordance with the inhibition of quercetin-triggered Ca2+ release by trans-Ned-19, a blocker of two-pore channels. As quercetin depleted intracellular Ca2+ storage, it suppressed ATP-induced Ca2+ release and thereby blunted ATP-triggered Ca2+ signaling. In addition, quercetin co-treatment significantly suppressed ATP-stimulated nitric oxide release. Our work therefore showed, for the first time, quercetin perturbed intracellular Ca2+ stores and strongly suppressed ATP-triggered response in bEnd.3 cells.
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Affiliation(s)
- Cing-Yu Chen
- School of Pharmacy, China Medical University, Taichung, 40402, Taiwan
| | - Mann-Jen Hour
- School of Pharmacy, China Medical University, Taichung, 40402, Taiwan
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, Taichung, 40402, Taiwan
| | - Kar-Lok Wong
- Department of Anesthesiology, China Medical University Hospital, Taichung, 40402, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, 40402, Taiwan
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Taipei Medical University Wan Fang Hospital, Taipei City, 116, Taiwan
| | - Edmund Cheung So
- Department of Anesthesia, An Nan Hospital, China Medical University, Tainan City, 709, Taiwan
- Graduate Institute of Medical Sciences, Chang Jung Christian University, Tainan City, 71101, Taiwan
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13
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Chow LWC, Cheng KS, Leong F, Cheung CW, Shiao LR, Leung YM, Wong KL. Enhancing tetrandrine cytotoxicity in human lung carcinoma A549 cells by suppressing mitochondrial ATP production. Naunyn Schmiedebergs Arch Pharmacol 2018; 392:427-436. [PMID: 30547225 DOI: 10.1007/s00210-018-01601-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 12/06/2018] [Indexed: 12/12/2022]
Abstract
ATP depletion induced by inhibiting glycolysis or mitochondrial ATP production has been demonstrated to cause cancer cell death. Whether ATP depletion can enhance the efficacy and potency of anti-cancer effects of herbal compounds is so far unknown. We examined the enhancing effect of ATP depletion on anti-cancer actions of tetrandrine (TET) in human lung carcinoma A549 cells. A 24-h incubation of A549 cells with tetrandrine caused a concentration-dependent cytotoxic effect (LC50 = 66.1 μM). Co-incubation with 20 mM 2-deoxyglucose (2-DG, glycolysis inhibitor) caused only a very slight enhancement of tetrandrine cytotoxicity. By contrast, inhibiting mitochondrial ATP production with oligomycin (10 μM, ATP synthase inhibitor) and FCCP (30 μM, uncoupling agent) (thus, oligo-FCCP) on its own caused only slight cell cytotoxicity but strongly potentiated tetrandrine cytotoxicity (tetrandrine LC50 = 15.6 μM). The stronger enhancing effect of oligo-FCCP than 2-DG on TET toxicity did not result from more severe overall ATP depletion, since both treatments caused a similar ATP level suppression. Neither oligo-FCCP nor 2-DG synergized with tetrandrine in decreasing mitochondrial membrane potential. TET on its own triggered reactive oxygen species (ROS) production, and oligo-FCCP, but not 2-DG, potentiated TET in causing ROS production. Taken together, our results suggest that inhibiting ATP production from mitochondria, but not from glycolysis, appears to be a very effective means in augmenting TET-triggered ROS production and hence toxicity in A549 cells.
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Affiliation(s)
- Louis W C Chow
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Macau, China
- UNIMED Medical Institute and Organisation for Oncology and Translational Research, Hong Kong, China
- Organisation for Oncology and Translational Research, Hong Kong, China
| | - Ka-Shun Cheng
- Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan
| | - Fai Leong
- Department of Anaesthesiology of Centro Hospitalar conde de Sao Januario, Macao Health Bureau, Macau, SAR, China
| | - Chi-Wai Cheung
- Laboratory and Clinical Research Institute for Pain, Department of Anaesthesiology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, No.91, Hsueh-Shih Road, Taichung, 40402, Taiwan, Republic of China
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, No.91, Hsueh-Shih Road, Taichung, 40402, Taiwan, Republic of China.
| | - Kar-Lok Wong
- Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan.
- Laboratory and Clinical Research Institute for Pain, Department of Anaesthesiology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, China.
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14
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Tsai TY, Leong IL, Cheng KS, Shiao LR, Su TH, Wong KL, Chan P, Leung YM. Lysophosphatidylcholine-induced cytotoxicity and protection by heparin in mouse brain bEND.3 endothelial cells. Fundam Clin Pharmacol 2018; 33:52-62. [PMID: 29974515 DOI: 10.1111/fcp.12399] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 06/28/2018] [Accepted: 07/03/2018] [Indexed: 11/29/2022]
Affiliation(s)
- Tien-Yao Tsai
- Cardiovascular Division; Fu Jen Catholic University Hospital; New Taipei City Taiwan
- School of Medicine; College of Medicine; Fu Jen Catholic University; New Taipei City Taiwan
| | - Iat-Lon Leong
- Division of Cardiology; Department of Internal Medicine; Kiang Wu Hospital; Macau China
| | - Ka-Shun Cheng
- Department of Anesthesiology; China Medical University Hospital; Taichung Taiwan
- Department of Anesthesiology; The Qingdao University Yuhuangding Hospital; Yantai Shandong China
| | - Lian-Ru Shiao
- Department of Physiology; China Medical University; Taichung Taiwan
| | - Tzu-Hui Su
- Department of Anesthesiology; China Medical University Hospital; Taichung Taiwan
| | - Kar-Lok Wong
- Department of Anesthesiology; China Medical University Hospital; Taichung Taiwan
| | - Paul Chan
- Division of Cardiology; Department of Medicine; Taipei Medical University Wan Fang Hospital; Taipei Taiwan
| | - Yuk-Man Leung
- Department of Physiology; China Medical University; Taichung Taiwan
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15
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Leung YM, Cave NJ, Hodgson B. Creation of a predictive equation to estimate fat-free mass and the ratio of fat-free mass to skeletal size using morphometry in lean working farm dogs. N Z Vet J 2018; 66:248-256. [PMID: 29949729 DOI: 10.1080/00480169.2018.1492984] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
AIMS To develop an equation that accurately estimates fat-free mass (FFM) and the ratio of FFM to skeletal size or mass, using morphometric measurements in lean working farm dogs, and to examine the association between FFM derived from body condition score (BCS) and FFM measured using isotope dilution. METHODS Thirteen Huntaway and seven Heading working dogs from sheep and beef farms in the Waikato region of New Zealand were recruited based on BCS (BCS < 3, 3-4, > 4) using a nine-point scale. Bodyweight, BCS, and morphometric measurements (head length and circumference, body length, thoracic girth, and fore and hind limb length) were recorded for each dog, and body composition was measured using an isotopic dilution technique. A new variable using morphometric measurements, termed skeletal size, was created using principal component analysis. Models for predicting FFM, leanST (FFM minus skeletal mass) and ratios of FFM and leanST to skeletal size or mass were generated using multiple linear regression analysis. RESULTS Mean FFM of the 20 dogs, measured by isotope dilution, was 22.1 (SD 4.4) kg and the percentage FFM of bodyweight was 87.0 (SD 5.0)%. Median BCS was 3.0 (min 1, max 6). Bodyweight, breed, age and skeletal size or mass were associated with measured FFM (p<0.001). There was a good correlation between predicted FFM and measured FFM (R2=0.96), and for the ratio of predicted FFM to skeletal size and measured values (R2=0.99). Correlation coefficients were higher for the ratio FFM and leanST to skeletal size than for ratios using skeletal mass. There was a positive correlation between BCS-derived fat mass as a percentage of bodyweight and fat mass percentage determined using isotope dilution (R2=0.65). CONCLUSIONS AND CLINICAL RELEVANCE As expected, the predictive equation was accurate in estimating FFM when tested on the same group of dogs used to develop the equation. The significance of breed, independent of skeletal size, in predicting FFM indicates that individual breed formulae may be required. Future studies that apply these equations on a greater population of working Huntaway and Heading dogs are needed to establish the utility of these equations on a large scale. Such studies could ascertain if there is a ratio for lean mass to skeletal size below which the risk of injury or disease increases. If these equations prove useful they would provide an objective and non-invasive measure to determine when welfare in individual dogs is compromised by underfeeding.
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Affiliation(s)
- Y M Leung
- a School of Veterinary Science , Massey University , Palmerston North , New Zealand
| | - N J Cave
- a School of Veterinary Science , Massey University , Palmerston North , New Zealand
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16
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Leong IL, Tsai TY, Wong KL, Shiao LR, Cheng KS, Chan P, Leung YM. Valproic acid inhibits ATP-triggered Ca 2+ release via a p38-dependent mechanism in bEND.3 endothelial cells. Fundam Clin Pharmacol 2018; 32:499-506. [PMID: 29752814 DOI: 10.1111/fcp.12381] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 04/22/2018] [Accepted: 05/04/2018] [Indexed: 01/06/2023]
Abstract
Valproic acid (VA) is currently used to treat epilepsy and bipolar disorder. It has also been demonstrated to promote neuroprotection and neurogenesis. Although beneficial actions of VA on brain blood vessels have also been demonstrated, the effects of VA on brain endothelial cell (EC) Ca2+ signaling are hitherto unreported. In this report, we examined the effects of VA on agonist-triggered Ca2+ signaling in mouse cortical bEND.3 EC. While VA (100 μm) did not cause an acute inhibition of ATP-triggered Ca2+ signaling, a 30-min VA treatment strongly suppressed ATP-triggered intracellular Ca2+ release; however, such treatment did not affect Ca2+ release triggered by cyclopiazonic acid, an inhibitor of SERCA Ca2+ pump, suggesting there was no reduction in Ca2+ store size. VA-activated p38 signaling, and VA-induced inhibition of ATP-triggered Ca2+ release was prevented by SB203580, a p38 inhibitor, suggesting VA caused the inhibition by activating p38. Remarkably, VA treatment did not affect acetylcholine-triggered Ca2+ release, suggesting VA may not inhibit inositol 1,4,5-trisphosphate-induced Ca2+ release per se, and may not act directly on Gq or phospholipase C. Taken together, our results suggest VA treatment, via a p38-dependent mechanism, led to an inhibition of purinergic receptor-effector coupling.
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Affiliation(s)
- Iat-Lon Leong
- Division of Cardiology, Department of Internal Medicine, Kiang Wu Hospital, 33 Estrada do Repouso, Macau, China
| | - Tien-Yao Tsai
- School of Medicine, College of Medicine, Fu Jen Catholic University, 510 Zhongzheng Road, New Taipei City, Taiwan.,Cardiovascular Division, Fu Jen Catholic University Hospital, 69 Guizi Road, New Taipei City, Taiwan
| | - Kar-Lok Wong
- Department of Anesthesiology, China Medical University Hospital, 2 Yude Road, Taichung, Taiwan
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, 91 Hsuehshi Road, Taichung, Taiwan
| | - Ka-Shun Cheng
- Department of Anesthesiology, China Medical University Hospital, 2 Yude Road, Taichung, Taiwan.,Department of Anesthesiology, The Qingdao University Yuhuangding Hospital, 20 Yuhuangding East Road, Yantai, Shandong, China
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Taipei Medical University Wan Fang Hospital, 111 Xinglong Road, Taipei, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, 91 Hsuehshi Road, Taichung, Taiwan
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17
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Chen CY, Lin WC, Wong KL, Cheng KS, Leung YM, Yang SE. Gossypol stimulates opening of a Ca2+
- and Na+
-permeable but Ni2+
- and Co2+
-impermeable pore in bEND.3 endothelial cells. Clin Exp Pharmacol Physiol 2018; 45:788-796. [PMID: 29498086 DOI: 10.1111/1440-1681.12929] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 02/13/2018] [Accepted: 02/17/2018] [Indexed: 12/29/2022]
Affiliation(s)
- Cing-Yu Chen
- School of Pharmacy; China Medical University; Taichung Taiwan
| | - Wen-Chuan Lin
- School of Pharmacy; China Medical University; Taichung Taiwan
| | - Kar-Lok Wong
- Department of Anesthesiology; China Medical University Hospital; Taichung Taiwan
| | - Ka-Shun Cheng
- Department of Anesthesiology; China Medical University Hospital; Taichung Taiwan
- Department of Anesthesiology; The Qingdao University Yuhuangding Hospital; Yantai Shandong China
| | - Yuk-Man Leung
- Department of Physiology; China Medical University; Taichung Taiwan
| | - Shu-Er Yang
- Department of Beauty Science and Graduate Institute of Beauty Science and Technology; Chienkuo Technology University; Changhua Taiwan
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18
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Abstract
Objective A variety of ion channels have been implicated in breast cancer proliferation and metastasis. Voltage-gated K+ (Kv) channels not only cause repolarization in excitable cells, but are also involved in multiple cellular functions in non-excitable cells. In this study we investigated the role of Kv channels in migration of BT474 breast cancer cells. Methods Transwell technique was used to separate migratory cells from non-migratory ones and these two groups of cells were subject to electrophysiological examinations and microfluorimetric measurements for cytosolic Ca2+. Cell migration was examined in the absence or presence of Kv channel blockers. Results When compared with non-migratory cells, migratory cells had much higher Kv current densities, but rather unexpectedly, more depolarized membrane potential and reduced Ca2+ influx. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed the presence of Kv1.1, Kv1.3, Kv1.5, Kv2.1, Kv3.3, Kv3.4 and Kv4.3 channels. Cell migration was markedly inhibited by tetraethylammonium (TEA), a delayed rectifier Kv channel blocker, but not by 4-aminopyridine, an A-type Kv channel blocker. Conclusions Taken together, our results show that increased Kv channel expression played a role in BT474 cell migration, and Kv channels could be considered as biomarkers or potential therapeutic targets for breast cancer metastasis. The mechanism(s) by which Kv channels enhanced migration appeared unrelated to membrane hyperpolarization and Ca2+ influx.
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Affiliation(s)
- Louis Wc Chow
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Taipa, Macau 999078, China.,UNIMED Medical Institute, Hong Kong 999077, China.,Organisation for Oncology and Translational Research, Hong Kong 999077, China
| | - Ka-Shun Cheng
- Department of Anesthesiology, China Medical University Hospital, Taichung 40447, Taiwan, China.,Department of Anesthesiology, the Qingdao University Yuhuangding Hospital, Yantai 264000, China
| | - Kar-Lok Wong
- Department of Anesthesiology, China Medical University Hospital, Taichung 40447, Taiwan, China
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung 40402, Taiwan, China
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19
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Wu KC, Wong KL, Wang ML, Shiao LR, Leong IL, Gong CL, Cheng KS, Chan P, Leung YM. Eicosapentaenoic acid triggers Ca 2+ release and Ca 2+ influx in mouse cerebral cortex endothelial bEND.3 cells. J Physiol Sci 2018; 68:33-41. [PMID: 27873157 PMCID: PMC10717322 DOI: 10.1007/s12576-016-0503-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Accepted: 11/11/2016] [Indexed: 11/29/2022]
Abstract
Eicosapentaenoic acid (EPA), an omega-3 fatty acid abundant in fish oil, protects endothelial cells (EC) from lipotoxicity and triggers EC NO release. The latter is related to an elevation of cytosolic Ca2+. Although EPA has been shown to cause human EC cytosolic Ca2+ elevation, the mechanism is unclear. Microfluorimetric imaging was used here to measure free cytosolic Ca2+ concentration. EPA was shown to cause intracellular Ca2+ release in mouse cerebral cortex endothelial bEND.3 cells; interestingly, the EPA-sensitive intracellular Ca2+ pool(s) appeared to encompass and was larger than the Ca2+ pool mobilized by sarcoplasmic-endoplasmic reticulum Ca2+-ATPase inhibition by cyclopiazonic acid. EPA also opened a Ca2+ influx pathway pharmacologically distinct from store-operated Ca2+ influx. Surprisingly, EPA-triggered Ca2+ influx was Ni2+-insensitive; and EPA did not trigger Mn2+ influx. Further, EPA-triggered Ca2+ influx did not involve Na+-Ca2+ exchangers. Thus, our results suggest EPA triggered unusual mechanisms of Ca2+ release and Ca2+ influx in EC.
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Affiliation(s)
- King-Chuen Wu
- Department of Anesthesiology, Chang Gung Memorial Hospital, Chiayi, Taiwan
- Chang Gung University of Science and Technology, Chiayi, Taiwan
| | - Kar-Lok Wong
- Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan
| | - Mei-Ling Wang
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Lian-Ru Shiao
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Iat-Lon Leong
- Division of Cardiology, Department of Internal Medicine, Kiang Wu Hospital, Macau, China
| | - Chi-Li Gong
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Ka-Shun Cheng
- Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan
- Department of Anesthesiology, The Qingdao University Yuhuangding Hospital, Yantai, Shandong, China
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Taipei Medical University Wan Fang Hospital, Taipei, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, Taiwan.
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20
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Chao HH, Chen PY, Hao WR, Chiang WP, Cheng TH, Loh SH, Leung YM, Liu JC, Chen JJ, Sung LC. Lipopolysaccharide pretreatment increases protease-activated receptor-2 expression and monocyte chemoattractant protein-1 secretion in vascular endothelial cells. J Biomed Sci 2017; 24:85. [PMID: 29141644 PMCID: PMC5688698 DOI: 10.1186/s12929-017-0393-1] [Citation(s) in RCA: 12] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 11/07/2017] [Indexed: 01/22/2023] Open
Abstract
Background This study investigated whether lipopolysaccharide (LPS) increase protease-activated receptor-2 (PAR-2) expression and enhance the association between PAR-2 expression and chemokine production in human vascular endothelial cells (ECs). Methods The morphology of ECs was observed through microphotography in cultured human umbilical vein ECs (EA. hy926 cells) treated with various LPS concentrations (0, 0.25, 0.5, 1, and 2 μg/mL) for 24 h, and cell viability was assessed using the MTT assay. Intracellular calcium imaging was performed to assess agonist (trypsin)-induced PAR-2 activity. Western blotting was used to explore the LPS-mediated signal transduction pathway and the expression of PAR-2 and adhesion molecule monocyte chemoattractant protein-1 (MCP-1) in ECs. Results Trypsin stimulation increased intracellular calcium release in ECs. The calcium influx was augmented in cells pretreated with a high LPS concentration (1 μg/mL). After 24 h treatment of LPS, no changes in ECs viability or morphology were observed. Western blotting revealed that LPS increased PAR-2 expression and enhanced trypsin-induced extracellular signal-regulated kinase (ERK)/p38 phosphorylation and MCP-1 secretion. However, pretreatment with selective ERK (PD98059), p38 mitogen-activated protein kinase (MAPK) (SB203580) inhibitors, and the selective PAR-2 antagonist (FSLLRY-NH2) blocked the effects of LPS-activated PAR-2 on MCP-1 secretion. Conclusions Our findings provide the first evidence that the bacterial endotoxin LPS potentiates calcium mobilization and ERK/p38 MAPK pathway activation and leads to the secretion of the pro-inflammatory chemokine MCP-1 by inducing PAR-2 expression and its associated activity in vascular ECs. Therefore, PAR-2 exerts vascular inflammatory effects and plays an important role in bacterial infection-induced pathological responses. Electronic supplementary material The online version of this article (10.1186/s12929-017-0393-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hung-Hsing Chao
- Division of Cardiovascular Surgery, Department of Surgery, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, 111, Taiwan.,Department of Surgery, School of Medicine, Taipei Medical University, Taipei, 11031, Taiwan
| | - Po-Yuan Chen
- Department of Biological Science and Technology, College of Biopharmaceutical and Food Sciences, China Medical University, Taichung, 40402, Taiwan
| | - Wen-Rui Hao
- Division of Cardiology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, No. 291, Zhongzheng Rd, Zhonghe District, New Taipei City, 23561, Taiwan
| | - Wei-Ping Chiang
- Division of Cardiology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, No. 291, Zhongzheng Rd, Zhonghe District, New Taipei City, 23561, Taiwan
| | - Tzu-Hurng Cheng
- Department of Biochemistry, School of Medicine, China Medical University, Taichung, 40402, Taiwan.,Department of Pharmacology & Graduate Institute of Pharmacology, National Defense Medical Center, Taipei, 114, Taiwan
| | - Shih-Hurng Loh
- Department of Pharmacology & Graduate Institute of Pharmacology, National Defense Medical Center, Taipei, 114, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, School of Medicine, China Medical University, Taichung, 40402, Taiwan
| | - Ju-Chi Liu
- Division of Cardiology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, No. 291, Zhongzheng Rd, Zhonghe District, New Taipei City, 23561, Taiwan.,Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, 11031, Taiwan
| | - Jin-Jer Chen
- Graduate Institute of Clinical Medicine, College of Medicine, China Medical University, Taichung, 40402, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, Taipei, 115, Taiwan
| | - Li-Chin Sung
- Division of Cardiology, Department of Internal Medicine, Shuang Ho Hospital, Taipei Medical University, No. 291, Zhongzheng Rd, Zhonghe District, New Taipei City, 23561, Taiwan. .,Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, 11031, Taiwan.
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21
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Wu KC, Cheng KS, Wang YW, Chen YF, Wong KL, Su TH, Chan P, Leung YM. Perturbation of Akt Signaling, Mitochondrial Potential, and ADP/ATP Ratio in Acidosis-Challenged Rat Cortical Astrocytes. J Cell Biochem 2017; 118:1108-1117. [PMID: 27608291 DOI: 10.1002/jcb.25725] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Accepted: 09/07/2016] [Indexed: 12/17/2022]
Abstract
Cells switch to anaerobic glycolysis when there is a lack of oxygen during brain ischemia. Extracellular pH thus drops and such acidosis causes neuronal cell death. The fate of astrocytes, mechanical, and functional partners of neurons, in acidosis is less studied. In this report, we investigated the signaling in acidosis-challenged rat cortical astrocytes and whether these signals were related to mitochondrial dysfunction and cell death. Exposure to acidic pH (6.8, 6.0) caused Ca2+ release and influx, p38 MAPK activation, and Akt inhibition. Mitochondrial membrane potential was hyperpolarized after astrocytes were exposed to acidic pH as soon as 1 h and lasted for 24 h. Such mitochondrial hyperpolarization was prevented by SC79 (an Akt activator) but not by SB203580 (a p38 inhibitor) nor by cytosolic Ca2+ chelation by BAPTA, suggesting that only the perturbation in Akt signaling was causally related to mitochondrial hyperpolarization. SC79, SB203580, and BAPTA did not prevent acidic pH-induced cell death. Acidic pH suppressed ROS production, thus ruling out the role of ROS in cytotoxicity. Interestingly, pH 6.8 caused an increase in ADP/ATP ratio and apoptosis; pH 6.0 caused a further increase in ADP/ATP ratio and necrosis. Therefore, astrocyte cell death in acidosis did not result from mitochondrial potential collapse; in case of acidosis at pH 6.0, necrosis might partly result from mitochondrial hyperpolarization and subsequent suppressed ATP production. J. Cell. Biochem. 118: 1108-1117, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- King-Chuen Wu
- Department of Anesthesiology, Chang Gung Memorial Hospital, Chiayi, Taiwan.,Chang Gung University of Science and Technology, Chiayi, Taiwan
| | - Ka-Shun Cheng
- Department of Anesthesiology, China Medical University and Hospital, Taichung, Taiwan.,Department of Anesthesiology, The Qingdao University Yuhuangding Hospital, Yantai, Shandong, China
| | - Yu-Wen Wang
- Department of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung, Taiwan
| | - Yuh-Fung Chen
- Department of Pharmacology, China Medical University, Taichung, Taiwan
| | - Kar-Lok Wong
- Department of Anesthesiology, China Medical University and Hospital, Taichung, Taiwan
| | - Tzu-Hui Su
- Department of Anesthesiology, China Medical University and Hospital, Taichung, Taiwan
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Taipei Medical University Wan Fang Hospital, Taipei, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, Taiwan
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22
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Yang CT, Leung YM, Hsu SF, MacDonald I, Wang ML, Lin JG, Hung SY, Chen YH. A comparison of the delayed outward potassium current between the nucleus ambiguus and hippocampus: sensitivity to paeonol. Eur J Pharmacol 2016; 784:49-60. [PMID: 27164420 DOI: 10.1016/j.ejphar.2016.04.057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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: 10/11/2015] [Revised: 04/26/2016] [Accepted: 04/28/2016] [Indexed: 01/31/2023]
Abstract
Whole-cell patch-clamp recordings investigated the electrophysiological effects of 2'-hydroxy-4'-methoxyacetophenone (paeonol), one of the major components of Moutan Cortex, in hippocampal CA1 neurons and nucleus ambiguus (NA) neurons from neonatal rats as well as in lung epithelial H1355 cells expressing Kv2.1 or Kv1.2. Extracellular application of paeonol at 100μM did not significantly affect the spontaneous action potential frequency, whereas paeonol at 300μM increased the frequency of spontaneous action potentials in hippocampal CA1 neurons. Paeonol (300μM) significantly decreased the tetraethylammonium-sensitive outward current in hippocampal CA1 neurons, but had no effect upon the fast-inactivating potassium current (IA). Extracellular application of paeonol at 300μM did not affect action potentials or the delayed outward currents in NA neurons. Paeonol (100μM) reduced the Kv2.1 current in H1355 cells, but not the Kv1.2 current. The inhibitor of Kv2, guangxitoxin-1E, reduced the delayed outward potassium currents in hippocampal neurons, but had only minimal effects in NA neurons. We demonstrated that paeonol decreased the delayed outward current and increased excitability in hippocampal CA1 neurons, whereas these effects were not observed in NA neurons. These effects may be associated with the inhibitory effects on Kv2.1 currents.
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Affiliation(s)
- Chin-Tsang Yang
- School of Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Sheng-Feng Hsu
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
| | - Iona MacDonald
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
| | - Mei-Ling Wang
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Jaung-Geng Lin
- School of Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Shih-Ya Hung
- Division of Colorectal Surgery, China Medical University Hospital, Taichung, Taiwan; Graduate Institute of Integrated Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan.
| | - Yi-Hung Chen
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan; Department of Photonics and Communication Engineering, Asia University, Taiwan.
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23
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Tsai TY, Chan P, Gong CL, Wong KL, Su TH, Shen PC, Leung YM, Liu ZM. Parthenolide-Induced Cytotoxicity in H9c2 Cardiomyoblasts Involves Oxidative Stress. Acta Cardiol Sin 2016; 31:33-41. [PMID: 27122844 DOI: 10.6515/acs20140422b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Cardiac cellular injury as a consequence of ischemia and reperfusion involves nuclear factor-κB (NF-κ B), amongst other factors, and NF-κ B inhibitors could substantially reduce myocardial infarct size. Parthenolide, a sesquiterpene lactone compound which could inhibit NF-κ B, has been shown to ameliorate myocardial reperfusion injury but may also produce toxic effects in cardiomyocytes at high concentrations. The aim of this study was to examine the cytotoxic effects of this drug on H9c2 cardiomyoblasts, which are precursor cells of cardiomyocytes. METHODS Cell viability and apoptosis were examined by MTT and TUNEL assay, respectively, and protein expression was analyzed by western blot. Reactive oxygen species (ROS) production was measured using DCFH-DA as dye. Cytosolic Ca(2+) concentration and mitochondrial membrane potential were measured microfluorimetrically using, respectively, fura 2 and rhodamine 123 as dyes. RESULTS Parthenolide caused apoptosis at 30 μ M, as judged by TUNEL assay and Bax and cytochrome c translocation. It also caused collapse of mitochondrial membrane potential and endoplasmic reticulum stress. Parthenolide triggered ROS formation, and vitamin C (antioxidant) partially alleviated parthenolide-induced cell death. CONCLUSIONS The results suggested that parthenolide at high concentrations caused cytotoxicity in cardiomyoblasts in part by inducing oxidative stress, and demonstrated the imperative for cautious and appropriate use of this agent in cardioprotection. KEY WORDS Cardiomyoblast; Endoplasmic reticulum stress; Oxidative stress; Parthenolide; Reperfusion injury.
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Affiliation(s)
- Tien-Yao Tsai
- Cardiovascular Division, Lotung Poh-Ai Hospital, Luodong; ; Department of Biomedical Engineering, Chung Yuan Christian University, Chungli
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Taipei Medical University Wan Fan Hospital, Taipei
| | - Chi-Li Gong
- Department of Physiology, China Medical University
| | - Kar-Lok Wong
- Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan
| | - Tzu-Hui Su
- Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan
| | - Pei-Chen Shen
- Department of Cardiology, Shanghai East Hospital, Tongji University, Shanghai, China
| | - Yuk-Man Leung
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan
| | - Zhong-Min Liu
- Department of Cardiovascular Surgery, Shanghai East Hospital, Tongji University, Shanghai, China
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Tsai TY, Lou SL, Cheng KS, Wong KL, Wang ML, Su TH, Chan P, Leung YM. Repressed Ca2+ clearance in parthenolide-treated murine brain bEND.3 endothelial cells. Eur J Pharmacol 2015; 769:280-6. [DOI: 10.1016/j.ejphar.2015.11.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 11/15/2015] [Accepted: 11/18/2015] [Indexed: 12/19/2022]
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Chen JH, Tsai CH, Lin HY, Huang CF, Leung YM, Lai SW, Tsai CF, Chang PC, Lu DY, Lin C. Interlukin-18 Is a Pivot Regulatory Factor on Matrix Metalloproteinase-13 Expression and Brain Astrocytic Migration. Mol Neurobiol 2015; 53:6218-6227. [PMID: 26558633 DOI: 10.1007/s12035-015-9529-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [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: 09/24/2015] [Accepted: 11/05/2015] [Indexed: 01/28/2023]
Abstract
The expression of matrix metalloproteinase-13 (MMP-13) has been shown to be elevated in some pathophysiological conditions and is involved in the degradation of extracellular matrix in astrocytes. In current study, the function of MMP-13 was further investigated. The conditioned medium (CM) collected from activated microglia increased interleukin (IL)-18 production and enhanced MMP-13 expression in astrocytes. Furthermore, treatment with recombinant IL-18 increased MMP-13 protein and mRNA levels in astrocytes. Recombinant IL-18 stimulation also increased the enzymatic activity of MMP-13 and the migratory activity of astrocytes, while administration of MMP-13 or pan-MMP inhibitors antagonized IL-18-induced migratory activity of astrocytes. In addition, administration of recombinant IL-18 to astrocytes led to the phosphorylation of JNK, Akt, or PKCδ, and treatment of astrocytes with JNK, PI3 kinase/Akt, or PKCδ inhibitors significantly decreased the IL-18-induced migratory activity. Taken together, the results suggest that IL-18-induced MMP-13 expression in astrocytes is regulated by JNK, PI3 kinase/Akt, and PKCδ signaling pathways. These findings also indicate that IL-18 is an important regulator leading to MMP-13 expression and cell migration in astrocytes.
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Affiliation(s)
- Jia-Hong Chen
- Department of General Surgery, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan.,School of Medicine, Tzu Chi University, Hualien, Taiwan
| | - Chon-Haw Tsai
- Department of Neurology, China Medical University Hospital, Taichung, Taiwan.,Graduate Institute of Neural and Cognitive Sciences, China Medical University, No.91 Hsueh-Shih Road, Taichung, Taiwan
| | - Hsiao-Yun Lin
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, No.91 Hsueh-Shih Road, Taichung, Taiwan
| | - Chien-Fang Huang
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, No.91 Hsueh-Shih Road, Taichung, Taiwan
| | - Yuk-Man Leung
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, No.91 Hsueh-Shih Road, Taichung, Taiwan
| | - Sheng-Wei Lai
- Graduate Institute of Basic Medical Science, College of Medicine, China Medical University, Taichung, Taiwan
| | - Cheng-Fang Tsai
- Department of Biotechnology, Asia University, Taichung, Taiwan
| | - Pei-Chun Chang
- Department of Bioinformatics, Asia University, Taichung, Taiwan
| | - Dah-Yuu Lu
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, No.91 Hsueh-Shih Road, Taichung, Taiwan. .,Department of Photonics and Communication Engineering, Asia University, Taichung, Taiwan.
| | - Chingju Lin
- Department of Physiology, School of Medicine, China Medical University, No.91 Hsueh-Shih Road, Taichung, Taiwan.
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Tsai TY, Lou SL, Wong KL, Wang ML, Su TH, Liu ZM, Yeh LJ, Chan P, Gong CL, Leung YM. Suppression of Ca2+ influx in endotoxin-treated mouse cerebral cortex endothelial bEND.3 cells. Eur J Pharmacol 2015; 755:80-7. [DOI: 10.1016/j.ejphar.2015.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 03/01/2015] [Accepted: 03/03/2015] [Indexed: 12/17/2022]
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Wang YW, Yang CT, Gong CL, Chen YH, Chen YW, Wu KC, Cheng TH, Kuo YH, Chen YF, Leung YM. Inhibition of voltage-gated Na+ channels by hinokiol in neuronal cells. Pharmacol Rep 2015; 67:1049-54. [PMID: 26481521 DOI: 10.1016/j.pharep.2015.03.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [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: 11/06/2014] [Revised: 02/27/2015] [Accepted: 03/31/2015] [Indexed: 11/18/2022]
Abstract
BACKGROUND Hinokiol is a naturally occurring diterpenoid compound isolated from plants such as Taiwania cryptomerioides. Anti-oxidation, anti-cancer, and anti-inflammation effects of this compound have been reported. It is not yet known if hinokiol affects neurons or neuronal ion channel activities. We reported here that hinokiol inhibited voltage-gated Na(+) channels (VGSC) in neuronal cells and we characterized the mechanisms of block. METHODS The effects of hinokiol on Na(+) channels were examined using the voltage-clamp (whole-cell mode) technique. RESULTS VGSC was blocked by hinokiol in a concentration-dependent and state-dependent manner in neuroblastoma N2A cells: IC(50) are 11.3 and 37.4μM in holding potentials of -70 and -100 mV, respectively. In the presence of hinokiol there was a 13-mV left shift in steady-state inactivation curves; however, activation gating was not altered. VGSC inhibition by hinokiol did not require channel opening and was thus considered to be closed-channel block. In the presence of hinokiol, since the degree of block did not enhance with stimulation frequency, block by hinokiol thus did not exhibit use-dependence. Recovery from channel inactivation was not significantly affected in the presence of hinokiol. In addition, hinokiol also inhibited VGSC of differentiated neuronal NG108-15 cells and rat hippocampal CA1 neurons. CONCLUSION Our results therefore suggest hinokiol inhibited VGSC in a closed-channel block manner and such inhibition involved intensification of channel inactivation.
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Affiliation(s)
- Yu-Wen Wang
- Department of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung, Taiwan
| | - Chin-Tsang Yang
- School of Chinese Medicine, China Medical University, Taichung, Taiwan
| | - Chi-Li Gong
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Yi-Hung Chen
- Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan
| | - Yu-Wen Chen
- Department of Physical Therapy, China Medical University, Taichung, Taiwan
| | - King-Chuen Wu
- Department of Anesthesiology, Eda-Hospital, I-Shou University, Kaohsiung, Taiwan
| | - Tzu-Hurng Cheng
- Department of Biochemistry, China Medical University, Taichung, Taiwan
| | - Yueh-Hsiung Kuo
- Department of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung, Taiwan; Department of Biotechnology, Asia University, Taichung, Taiwan
| | - Yuh-Fung Chen
- Department of Pharmacology, China Medical University, Taichung, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, China Medical University, Taichung, Taiwan.
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Wu KC, Kuo CS, Chao CC, Huang CC, Tu YK, Chan P, Leung YM. Role of voltage-gated K(+) channels in regulating Ca(2+) entry in rat cortical astrocytes. J Physiol Sci 2015; 65:171-7. [PMID: 25617267 PMCID: PMC10717881 DOI: 10.1007/s12576-015-0356-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [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: 09/08/2014] [Accepted: 01/09/2015] [Indexed: 01/11/2023]
Abstract
Astrocytes have multiple functions such as provision of nourishment and mechanical support to the nervous system, helping to clear extracellular metabolites of neurons and modulating synaptic transmission by releasing gliotransmitters. In excitable cells, voltage-gated K(+) (Kv) channels serve to repolarize during action potentials. Astrocytes are considered non-excitable cells since they are not able to generate action potentials. There is an abundant expression of various Kv channels in astrocytes but the functions of these Kv channels remain unclear. We examined whether these astrocyte Kv channels regulate astrocyte "excitability" in the form of cytosolic Ca(2+) signaling. Electrophysiological examination revealed that neonatal rat cortical astrocytes possessed both delayed rectifier type and A-type Kv channels. Pharmacological blockade of both delayed rectifier Kv channels by TEA and A-type Kv channels by quinidine significantly suppressed store-operated Ca(2+) influx; however, TEA alone or quinidine alone did not suffice to cause such suppression. TEA and quinidine together dramatically enhanced current injection-triggered membrane potential overshoot (depolarization); either drug alone caused much smaller enhancements. Taken together, the results suggest both delayed rectifier and A-type Kv channels regulate astrocyte Ca(2+) signaling via controlling membrane potential.
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Affiliation(s)
- King-Chuen Wu
- Department of Anesthesiology, E-Da Hospital, I-Shou University, Kaohsiung, Taiwan
| | - Chang-Shin Kuo
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, 40402 Taiwan
| | - Chia-Chia Chao
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Chieh-Chen Huang
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Yuan-Kun Tu
- Orthopedic Department, E-Da Hospital, I-Shou University, Kaohsiung, Taiwan
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yuk-Man Leung
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, 40402 Taiwan
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Lin CH, Yang CT, Tsai MC, Wu YT, MacDonald I, Wang ML, Wu CH, Leung YM, Chen YH. (±)3,4-Methylenedioxyamphetamine inhibits the TEA-sensitive K+ current in the hippocampal neuron and the Kv2.1 current expressed in H1355 cells. Neuropharmacology 2015; 89:100-12. [DOI: 10.1016/j.neuropharm.2014.09.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 08/20/2014] [Accepted: 09/04/2014] [Indexed: 10/24/2022]
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Leung YM, Tzeng JI, Gong CL, Wang YW, Chen YW, Wang JJ. Caramiphen-induced block of sodium currents and spinal anesthesia. Eur J Pharmacol 2015; 746:213-20. [DOI: 10.1016/j.ejphar.2014.10.035] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 10/03/2014] [Accepted: 10/17/2014] [Indexed: 01/28/2023]
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Wong KL, Wu YR, Cheng KS, Chan P, Cheung CW, Lu DY, Su TH, Liu ZM, Leung YM. Palmitic acid-induced lipotoxicity and protection by (+)-catechin in rat cortical astrocytes. Pharmacol Rep 2014; 66:1106-13. [PMID: 25443742 DOI: 10.1016/j.pharep.2014.07.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [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: 03/14/2014] [Revised: 07/22/2014] [Accepted: 07/24/2014] [Indexed: 12/20/2022]
Abstract
BACKGROUND Astrocytes do not only maintain homeostasis of the extracellular milieu of the neurons, but also play an active role in modulating synaptic transmission. Palmitic acid (PA) is a saturated fatty acid which, when being excessive, is a significant risk factor for lipotoxicity. Activation of astrocytes by PA has been shown to cause neuronal inflammation and demyelination. However, direct damage by PA to astrocytes is relatively unexplored. The aim of this study was to identify the mechanism(s) of PA-induced cytotoxicity in rat cortical astrocytes and possible protection by (+)-catechin. METHODS Cytotoxicity and endoplasmic reticulum (ER) markers were assessed by MTT assay and Western blotting, respectively. Cytosolic Ca(2+) and mitochondrial membrane potential (MMP) were measured microfluorimetrically using fura-2 and rhodamine 123, respectively. Intracellular reactive oxygen species (ROS) production was assayed by the indicator 2'-7'-dichlorodihydrofluorescein diacetate. RESULTS Exposure of astrocytes to 100μM PA for 24h resulted in apoptotic cell death. Whilst PA-induced cell death appeared to be unrelated to ER stress and perturbation in cytosolic Ca(2+) signaling, it was likely a result of ROS production and subsequent MMP collapse, since ascorbic acid (anti-oxidant, 100μM) prevented PA-induced MMP collapse and cell death. Co-treatment of astrocytes with (+)-catechin (300μM), an anti-oxidant found abundantly in green tea, significantly prevented PA-induced ROS production, MMP collapse and cell death. CONCLUSION Our results suggest that PA-induced cytotoxicity in astrocytes may involve ROS generation and MMP collapse, which can be prevented by (+)-catechin.
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Affiliation(s)
- Kar-Lok Wong
- Department of Anesthesiology, China Medical University and Hospital, Taichung, Taiwan; Department of Anesthesiology, LKS Faculty of Medicine, University of Hong Kong, Hong Kong; Department of Anesthesiology, Shandong University Nanshan Branch of Qilu Hospital, China
| | - Yu-Ru Wu
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan
| | - Ka-Shun Cheng
- Department of Anesthesiology, China Medical University and Hospital, Taichung, Taiwan
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Taipei Medical University Wan Fan Hospital, Taipei, Taiwan
| | - Chi-Wai Cheung
- Department of Anesthesiology, LKS Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Dah-Yuu Lu
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan
| | - Tzu-Hui Su
- Department of Anesthesiology, China Medical University and Hospital, Taichung, Taiwan
| | - Zhong-Min Liu
- Department of Cardiovascular Surgery, Shanghai East Hospital, Tongji University, Shanghai, China.
| | - Yuk-Man Leung
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan.
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Chao CC, Chan P, Kuo CS, Gong CL, Cheng TH, Liu ZM, Shen PC, Huang CC, Leung YM. Protection of differentiated neuronal NG108-15 cells from P2X7 receptor-mediated toxicity by taurine. Pharmacol Rep 2014; 66:576-84. [PMID: 24948057 DOI: 10.1016/j.pharep.2014.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 01/07/2014] [Accepted: 01/13/2014] [Indexed: 01/23/2023]
Abstract
BACKGROUND Strong P2X7 receptor (P2X7R) activation causes Ca(2+) overload and consequent cell death. We previously showed that depletion of Ca(2+) stores and endoplasmic reticulum (ER) stress in differentiated NG108-15 neuronal cells contributed to P2X7R-mediated cytotoxicity. In this work, we assessed whether taurine (2-aminoethanesulfonic acid) could prevent this P2X7R-mediated cytotoxicity in this neuronal cell line. METHODS Cytotoxicity markers were assessed by MTT assay and Western blotting. Cytosolic Ca(2+) and mitochondrial Ca(2+) concentrations were measured microfluorimetrically using fura-2 and rhod-2, respectively. Intracellular reactive oxygen species (ROS) production was assayed by the indicator 2',7'-dichlorodihydrofluorescein diacetate. RESULTS Selective P2X7R agonist BzATP treatment causes neuronal cell death by causing cytosolic Ca(2+) overload, depletion of Ca(2+) stores, endoplasmic reticulum (ER) stress, and caspase-3 activation (cleaved caspase 3). Remarkably, taurine (10mM) pretreatment could prevent P2X7R-mediated neuronal cell death by blocking BzATP-mediated ER stress as determined by phosphorylated eukaryotic translation initiation factor 2α (peIF2α) and C/EBP-homologous protein (CHOP). However, taurine did not block BzATP-induced Ca(2+) overload and depletion of ER Ca(2+) stores. Interestingly, P2X7R activation did not result in mitochondrial Ca(2+) overload, nor did it affect mitochondrial membrane potential. BzATP-induced generation of intracellular reactive oxygen species (ROS) was prevented by taurine. CONCLUSIONS The neuroprotective effect by taurine is attributed to the suppression of P2X7R-mediated ER stress and ROS formation.
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Affiliation(s)
- Chia-Chia Chao
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan
| | - Paul Chan
- Division of Cardiology, Department of Medicine, Taipei Medical University Wan Fang Hospital, Taipei, Taiwan
| | - Chang-Shin Kuo
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan
| | - Chi-Li Gong
- Department of Physiology, China Medical University, Taichung, Taiwan
| | - Tzu-Hurng Cheng
- Department of Biological Sciences and Technology, China Medical University, Taichung, Taiwan
| | - Zhong-Min Liu
- Department of Cardiovascular Surgery, Shanghai East Hospital, Tongji University, Shanghai, China
| | - Pei-Chen Shen
- Department of Cardiology, Shanghai East Hospital, Tongji University, Shanghai, China
| | - Chieh-Chen Huang
- Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan.
| | - Yuk-Man Leung
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan.
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Gong CL, Leung YM, Wang MR, Lin NN, Lee TJF, Kuo JS. Neurochemicals involved in medullary control of common carotid blood flow. Curr Neuropharmacol 2014; 11:513-20. [PMID: 24403875 PMCID: PMC3763759 DOI: 10.2174/1570159x113119990044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2012] [Revised: 01/22/2013] [Accepted: 07/17/2013] [Indexed: 11/22/2022] Open
Abstract
The common carotid artery (CCA) supplies intra- and extra-cranial vascular beds. An area in the medulla controlling CCA blood flow is defined as the dorsal facial area (DFA) by Kuo et al. in 1987. In the DFA, presynaptic nitrergic and/or glutamatergic fibers innervate preganglionic nitrergic and/or cholinergic neurons which give rise to the preganglionic fibers of the parasympathetic 7th and 9th cranial nerves. Released glutamate from presynaptic nitrergic and/or glutamatergic fibers can activate N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors on preganglionic nitrergic and/or cholinergic neurons. By modulating this glutamate release, several neurochemicals including serotonin, arginine, nitric oxide, nicotine, choline and ATP in the DFA regulate CCA blood flow. Understanding the neurochemical regulatory mechanisms can provide important insights of the physiological roles of the DFA, and may help develop therapeutic strategies for diseases involving CCA blood flow, such as migraine, hypertensive disease, Alzheimer’s disease and cerebral ischemic stroke.
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Affiliation(s)
- Chi-Li Gong
- Department of Physiology, School of Medicine, China Medical University, Taiwan
| | - Yuk-Man Leung
- Department of Physiology, School of Medicine, China Medical University, Taiwan; ; Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taiwan
| | - Ming-Ren Wang
- Yuhing Junior College of Health Care and Management, Kaohsiung, Taiwan
| | - Nai-Nu Lin
- Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Tony Jer-Fu Lee
- Neuro-Medical Scientific Center and Center for Vascular Medicine, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan; ; Department of Medical Research, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan
| | - Jon-Son Kuo
- Neuro-Medical Scientific Center and Center for Vascular Medicine, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan; ; Department of Medical Research, Buddhist Tzu Chi General Hospital and Tzu Chi University, Hualien, Taiwan; ; Institute of Pharmacology and Toxicology, Tzu Chi University, Hualien, Taiwan
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Marzolini S, Leung YM, Alter DA, Wu G, Grace SL. Outcomes associated with cardiac rehabilitation participation in patients with musculoskeletal comorbidities. Eur J Phys Rehabil Med 2013; 49:775-783. [PMID: 24309503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
BACKGROUND Individuals with coronary artery disease (CAD) and musculoskeletal comorbidities (MSKCs) have much to gain from physical activity, yet are less likely to be referred to cardiac rehabilitation (CR) than those without MSKCs. Whether patients with MSKCs achieve demonstrated benefits of CR participation such as improved quantity and quality-of-life remains unknown. AIM To compare all-cause mortality, major acute cardiovascular events (MACEs), quality-of-life and psychosocial well-being in patients with CAD and coexisting MSKCs by CR participation. DESIGN Prospective and observational study in which patients were administered a questionnaire in the hospital and 1 year later. The cohort was linked to provincial databases. SETTING Eleven hospitals in Ontario, Canada. POPULATION CAD patients (N.=1680). METHODS CAD inpatients were administered a questionnaire assessing sociodemographic and clinical characteristics. Clinical data were extracted from charts. CR participation, quality-of-life, depressive symptoms, functional status, and physical activity behavior were measured 1 year later by questionnaire. The cohort was linked to provincial administrative databases to ascertain mortality and MACEs for a median of 2.7 years post-index cardiac hospitalization. Associations of CR participation with outcomes were tested after adjustment for differences in participation propensity. RESULTS Of study participants, 50.7% (851/1680) had MSKCs and of those with MSKCs, 49.8% (424/851) participated in CR. Patients with MSKCs who participated in CR had greater physical quality-of-life (P<0.03) and lower mortality than those with MSKCs who did not attend CR, after adjusting for propensity for CR participation (1.4% vs. 4%; participant vs. non-participants, P=0.03) - non-participants' hazard ratio 3.91 [95%CI,1.23-12.36]). There were no differences for MACEs. CONCLUSION Among those with MSKCs, participation in CR is associated with survival benefit and better physical quality-of-life compared to non-participants. CLINICAL REHABILITATION IMPACT Our findings showing the high prevalence of MSKCs in those with CAD and the benefits of CR, add to the literature that will provide the basis for exploration of initiatives to improve care for those with CAD and MSKC, and to overcome barriers to improved outcomes and reduced death. These results will help to guide focused research to optimize complex outpatient care in this group, including increasing the utilization of CR.
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Affiliation(s)
- S Marzolini
- Toronto Rehabilitation Institute, University Health Network, Toronto, Canada -
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Wu KC, Chen YH, Cheng KS, Kuo YH, Yang CT, Wong KL, Tu YK, Chan P, Leung YM. Suppression of voltage-gated Na(+) channels and neuronal excitability by imperatorin. Eur J Pharmacol 2013; 721:49-55. [PMID: 24113522 DOI: 10.1016/j.ejphar.2013.09.056] [Citation(s) in RCA: 19] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Revised: 09/07/2013] [Accepted: 09/22/2013] [Indexed: 11/24/2022]
Abstract
Imperatorin is a naturally occurring furocoumarin compound isolated from plants such as Angelica archangelica and Cnidium monnieri. It has multiple pharmacological effects including anticonvulsant effects. Here we determined the effects of imperatorin on voltage-gated Na(+) channels (VGSC) using whole-cell patch clamp techniques in differentiated neuronal NG108-15 cells. We showed that imperatorin inhibited VGSC; such inhibition did not show state-dependence. Imperatorin caused a left shift in the steady-state inactivation curve without affecting activation gating. The inhibition of VGSC by imperatorin displayed a mild frequency-dependence. Imperatorin was also shown to inhibit VGSC and action potential amplitude without affecting voltage-gated K(+) channels in rat hippocampal CA1 neurons. In conclusion, our results suggest that imperatorin dampens neuronal excitability by inhibiting VGSC.
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Affiliation(s)
- King-Chuen Wu
- Department of Anesthesiology, Eda-Hospital, I-Shou University, Kaohsiung, Taiwan
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Leung YM, Tzeng JI, Kuo CS, Chen YW, Chu CC, Wang JJ. The use of carbetapentane for spinal anesthesia and use-dependent block of sodium currents. Eur J Pharmacol 2013; 714:366-72. [DOI: 10.1016/j.ejphar.2013.07.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 06/19/2013] [Accepted: 07/04/2013] [Indexed: 10/26/2022]
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Leung YM, Chu CC, Kuo CS, Chen YW, Wang JJ. Nisoxetine blocks sodium currents and elicits spinal anesthesia in rats. Pharmacol Rep 2013; 65:350-7. [DOI: 10.1016/s1734-1140(13)71010-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 11/26/2012] [Indexed: 11/16/2022]
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38
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Chen YH, Wu KC, Yang CT, Tu YK, Gong CL, Chao CC, Tsai MF, Kuo YH, Leung YM. Coumarsabin hastens C-type inactivation gating of voltage-gated K+ channels. Eur J Pharmacol 2013; 704:41-8. [DOI: 10.1016/j.ejphar.2013.01.062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Revised: 01/30/2013] [Accepted: 01/31/2013] [Indexed: 11/16/2022]
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Chao CC, Huang CC, Lu DY, Wong KL, Chen YR, Cheng TH, Leung YM. Ca2+ store depletion and endoplasmic reticulum stress are involved in P2X7 receptor-mediated neurotoxicity in differentiated NG108-15 cells. J Cell Biochem 2012; 113:1377-85. [PMID: 22134903 DOI: 10.1002/jcb.24010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
P2X7 receptor (P2X7R) activation by extracellular ATP triggers influx of Na(+) and Ca(2+), cytosolic Ca(2+) overload and consequently cytotoxicity. Whether disturbances in endoplasmic reticulum (ER) Ca(2+) homeostasis and ER stress are involved in P2X7R-mediated cell death is unknown. In this study, a P2X7R agonist (BzATP) was used to activate P2X7R in differentiated NG108-15 neuronal cells. In a concentration-dependent manner, application of BzATP (10-100 µM) immediately raised cytosolic Ca(2+) concentration ([Ca(2+)]i) and caused cell death after a 24-h incubation. P2X7R activation for 2 h did not cause cell death but resulted in a sustained reduction in ER Ca2+ pool size, as evidenced by a diminished cyclopiazonic acid-induced Ca(2+) discharge (fura 2 assay) and a lower fluorescent signal in cells loaded with Mag-fura 2 (ER-specific Ca(2+)-fluorescent dye). Furthermore, P2X7R activation (2 h) led to the appearance of markers of ER stress [phosphorylated α subunit of eukaryotic initiation factor 2 (p-eIF2α) and C/EBP homologous protein (CHOP)] and apoptosis (cleaved caspase 3). Xestospongin C (XeC), an antagonist of inositol-1,4,5-trisphosphate (IP3) receptor (IP3R), strongly inhibited BzATP-triggered [Ca(2+)]i elevation, suggesting that the latter involved Ca(2+) release via IP3R. XeC pretreatment not only attenuated the reduction in Ca(2+) pool size in BzATP-treated cells, but also rescued cell death and prevented BzATP-induced appearance of ER stress and apoptotic markers. These novel observations suggest that P2X7R activation caused not only Ca(2+) overload, but also Ca(2+) release via IP3R, sustained Ca(2+) store depletion, ER stress and eventually apoptotic cell death.
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Affiliation(s)
- Chia-Chia Chao
- Department of Life Sciences, National Chung Hsing University, Taichung, 402, Taiwan
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40
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Chen YW, Shieh JP, Chen YC, Leung YM, Hung CH, Wang JJ. Cutaneous analgesia after subcutaneous injection of memantine and amantadine and their systemic toxicity in rats. Eur J Pharmacol 2012; 693:25-30. [DOI: 10.1016/j.ejphar.2012.07.037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 07/09/2012] [Accepted: 07/26/2012] [Indexed: 12/01/2022]
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41
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Lu DY, Chang CS, Yeh WL, Tang CH, Cheung CW, Leung YM, Liu JF, Wong KL. The novel phloroglucinol derivative BFP induces apoptosis of glioma cancer through reactive oxygen species and endoplasmic reticulum stress pathways. Phytomedicine 2012; 19:1093-1100. [PMID: 22819448 DOI: 10.1016/j.phymed.2012.06.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 04/20/2012] [Accepted: 06/19/2012] [Indexed: 06/01/2023]
Abstract
Prenyl-phloroglucinol derivatives from hop plants have been shown to have anticancer activities. This study is the first to investigate the anticancer effects of the new phloroglucinol derivative (2,4-bis(4-fluorophenylacetyl)phloroglucinol; BFP). BFP induced cell death and anti-proliferation in three glioma, U251, U87 and C6 cells, but not in primary human astrocytes. BFP-induced concentration-dependently cell death in glioma cells was determined by MTT and SRB assay. Moreover, BFP-induced apoptotic cell death in glioma cells was measured by Hochest 33258 staining and fluorescence-activated cell sorter (FACS) of propidine iodine (PI) analysis. Treatment of U251 human glioma cells with BFP was also found to induce reactive oxygen species (ROS) generation, which was detected by a fluorescence dye used FACS analysis. Treatment of BFP also increased a number of signature endoplasmic reticulum (ER) stress markers glucose-regulated protein (GRP)-78, GRP-94, IRE1, phosphorylation of eukaryotic initiation factor-2α (eIF-2α) and up-regulation of CAAT/enhancer-binding protein homologous protein (CHOP). Moreover, treatment of BFP also increased the down-stream caspase activation, such as pro-caspase-7 and pro-caspase-12 degradation, suggesting the induction of ER stress. Furthermore, BFP also induced caspase-9 and caspase-3 activation as well as up-regulation of cleaved PARP expression. Treatment of antioxidants, or pre-transfection of cells with GRP78 or CHOP siRNA reduced BFP-mediated apoptotic-related protein expression. Taken together, the present study provides evidences to support that ROS generation, GRP78 and CHOP activation are mediating the BFP-induced human glioma cell apoptosis.
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Affiliation(s)
- Dah-Yuu Lu
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan.
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42
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Leung YM, Chu CC, Kuo CS, Chen YW, Hung CH, Wang JJ. Isobolographic analysis of interaction between nisoxetine- and mepivacaine-induced spinal blockades in rats. Fundam Clin Pharmacol 2012; 28:88-94. [DOI: 10.1111/j.1472-8206.2012.01070.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 06/28/2012] [Accepted: 07/19/2012] [Indexed: 12/01/2022]
Affiliation(s)
- Yuk-Man Leung
- Graduate Institute of Neural and Cognitive Sciences; China Medical University; Taichung Taiwan
| | - Chin-Chen Chu
- Department of Anesthesiology; Chi-Mei Medical Center; Tainan Taiwan
- Department of Recreation and Health-Care Management; Chia Nan University of Pharmacy and Science; Tainan Taiwan
| | - Chang-Shin Kuo
- Graduate Institute of Neural and Cognitive Sciences; China Medical University; Taichung Taiwan
| | - Yu-Wen Chen
- Graduate Institute of Neural and Cognitive Sciences; China Medical University; Taichung Taiwan
- Department of Physical Therapy; China Medical University; Taichung Taiwan
| | - Ching-Hsia Hung
- Institute & Department of Physical Therapy; National Cheng Kung University; No.1 Ta-Hsueh Road Tainan Taiwan
| | - Jhi-Joung Wang
- Department of Medical Research; Chi-Mei Medical Center; Tainan Taiwan
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Gong CL, Wong KL, Cheng KS, Kuo CS, Chao CC, Tsai MF, Leung YM. Inhibitory effects of magnolol on voltage-gated Na+ and K+ channels of NG108-15 cells. Eur J Pharmacol 2012; 682:73-8. [PMID: 22374258 DOI: 10.1016/j.ejphar.2012.02.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 01/31/2012] [Accepted: 02/09/2012] [Indexed: 11/19/2022]
Abstract
Magnolol, a polyphenolic compound isolated from Houpu, a Chinese herb from the bark of Magnolia officinalis, has been reported to have in vitro and in vivo neuroprotective effects. In spite of these reported beneficial effects, studies on the direct impact of magnolol on neuronal ion channels have been scarce. Whether magnolol affects voltage-gated Na(+) channels (VGSC) and voltage-gated K(+) (Kv) channels is unknown. Using the whole-cell voltage-clamp method, we studied the effects of magnolol on voltage-gated ion channels in neuronal NG108-15 cells. Magnolol inhibited VGSC channels with mild state-dependence (IC(50) of 15 and 30 μM, at holding potentials of -70 and -100 mV, respectively). No frequency-dependence was observed in magnolol block. Magnolol caused a left-shift of 18 mV in the steady-state inactivation curve but did not affect the voltage-dependence of activation. Magnolol inhibited Kv channels with an IC(50) of 21 μM, and it caused a 20-mV left-shift in the steady-state inactivation curve without affecting the voltage-dependence of activation. In conclusion, magnolol is an inhibitor of both VGSC and Kv channels and these inhibitory effects may in part contribute to some of the reported neuroprotective effects of magnolol.
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Affiliation(s)
- Chi-Li Gong
- Department of Physiology, China Medical University, Taichung 40402, Taiwan
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Leung YM. Involvement of C-type inactivation gating in the actions of voltage-gated K+ channel inhibitors. Pharmacol Ther 2012; 133:151-8. [DOI: 10.1016/j.pharmthera.2011.10.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 10/13/2011] [Indexed: 01/14/2023]
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Huang YC, Gaisano HY, Leung YM. Electrophysiological identification of mouse islet α-cells: from isolated single α-cells to in situ assessment within pancreas slices. Islets 2011; 3:139-43. [PMID: 21623173 DOI: 10.4161/isl.3.4.16166] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Investigation of α-cells has long been constrained by their scarce population and localization at the islet mantle which exposes α-cells to injury by conventional islet isolation and dispersion to single cells that employ damaging enzymatic and mechanical means. To surmount these limitations, we recently reported employing the pancreas slice preparation which enables highly efficient acute in situ electrophysiological (patch clamp) examination of α-cells within its unperturbed native social environment with preserved paracrine regulation. In this review, we compare the electrophysiological properties of α-cells in these three preparations, and discuss the current view of glucose regulation of α-cells. We discuss current genetic mouse models that flurophore-tagged α-cells (GYY) and β-cells (MIP-GFP) which can reliably identify islet cells to facilitate their study. Combining these strategies should enable future studies directed at the precise assessment of the perturbation in intrinsic and paracrine regulation of α-cells contributing to abnormal glucose homeostasis in diabetes.
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Affiliation(s)
- Ya-Chi Huang
- Institute of Medical Sciences, University of Toronto, Toronto, Canada
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Kuo CS, Kwan CY, Gong CL, Tsai MF, Nishibe S, Tatsuzaki J, Leung YM. Apocynum venetum leaf aqueous extract inhibits voltage-gated sodium channels of mouse neuroblastoma N2A cells. J Ethnopharmacol 2011; 136:149-155. [PMID: 21530630 DOI: 10.1016/j.jep.2011.04.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 04/11/2011] [Accepted: 04/13/2011] [Indexed: 05/30/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Apocynum venetum Linn. (Apocynaceae family), also called Luobuma, is a shrub which grows widely in the Xinjiang Autonomous Region of China. Its leaves are used in herbal tea for the treatment of hypertension, anxiety and depression. Animal studies have also shown that Apocynum venetum leaf extract (AVLE) also exerts anti-depressant and anti-anxiety activities. The effects of AVLE on neuronal tissues in vitro are not fully understood. MATERIALS AND METHODS Using the whole-cell voltage-clamp method, we studied the effects of AVLE on ion channels in cultured mouse neuroblastoma N2A cells. RESULTS AVLE inhibited voltage-gated inward Na(+) current in a reversible and concentration-dependent manner (half-inhibitory concentration was 18 μg/ml and maximum inhibition at 100 μg/ml). AVLE specifically promoted steady-state inactivation of Na(+) channels but did not affect voltage-dependence of activation. The inhibitory effect was not use-dependent and was not affected by 300μM L-NAME, suggesting that NO was not involved in the action of AVLE in neuronal cells. AVLE also had a mild inhibitory effect on voltage-gated K(+) channels, but did not affect ATP-sensitive K(+) channels. CONCLUSIONS Since voltage-gated Na(+) and K(+) channels are associated with neuronal excitability and therefore affect neurotransmission, the modulation of neuronal ion channels by AVLE may exert neuropharmacological effects. In particular, the inhibition of voltage-gated Na(+) currents by AVLE may in part account for the psychopharmacological effects of this herbal remedy.
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Affiliation(s)
- Chang-Shin Kuo
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung 40402, Taiwan
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Leung YM, Huang CF, Chao CC, Lu DY, Kuo CS, Cheng TH, Chang LY, Chou CH. Voltage-gated K+ channels play a role in cAMP-stimulated neuritogenesis in mouse neuroblastoma N2A cells. J Cell Physiol 2011; 226:1090-8. [PMID: 20857407 DOI: 10.1002/jcp.22430] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Neuritogenesis is essential in establishing the neuronal circuitry. An important intracellular signal causing neuritogenesis is cAMP. In this report, we showed that an increase in intracellular cAMP stimulated neuritogenesis in neuroblastoma N2A cells via a PKA-dependent pathway. Two voltage-gated K(+) (Kv) channel blockers, 4-aminopyridine (4-AP) and tetraethylammonium (TEA), inhibited cAMP-stimulated neuritogenesis in N2A cells in a concentration-dependent manner that remarkably matched their ability to inhibit Kv currents in these cells. Consistently, siRNA knock down of Kv1.1, Kv1.4, and Kv2.1 expression reduced Kv currents and inhibited cAMP-stimulated neuritogenesis. Kv1.1, Kv1.4, and Kv2.1 channels were expressed in the cell bodies and neurites as shown by immunohistochemistry. Microfluorimetric imaging of intracellular [K(+)] demonstrated that [K(+)] in neurites was lower than that in the cell body. We also showed that cAMP-stimulated neuritogenesis may not involve voltage-gated Ca(2+) or Na(+) channels. Taken together, the results suggest a role of Kv channels and enhanced K(+) efflux in cAMP/PKA-stimulated neuritogenesis in N2A cells.
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Affiliation(s)
- Yuk-Man Leung
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan.
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Kang Y, Zhang Y, Liang T, Leung YM, Ng B, Xie H, Chang N, Chan J, Shyng SL, Tsushima RG, Gaisano HY. ATP modulates interaction of syntaxin-1A with sulfonylurea receptor 1 to regulate pancreatic beta-cell KATP channels. J Biol Chem 2010; 286:5876-83. [PMID: 21173146 DOI: 10.1074/jbc.m109.089607] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
ATP-sensitive potassium (K(ATP)) channels are regulated by a variety of cytosolic factors (adenine nucleotides, Mg(2+), phospholipids, and pH). We previously reported that K(ATP) channels are also regulated by endogenous membrane-bound SNARE protein syntaxin-1A (Syn-1A), which binds both nucleotide-binding folds of sulfonylurea receptor (SUR)1 and 2A, causing inhibition of K(ATP) channel activity in pancreatic islet β-cells and cardiac myocytes, respectively. In this study, we show that ATP dose-dependently inhibits Syn-1A binding to SUR1 at physiological concentrations, with the addition of Mg(2+) causing a decrease in the ATP-induced inhibitory effect. This ATP disruption of Syn-1A binding to SUR1 was confirmed by FRET analysis in living HEK293 cells. Electrophysiological studies in pancreatic β-cells demonstrated that reduced ATP concentrations increased K(ATP) channel sensitivity to Syn-1A inhibition. Depletion of endogenous Syn-1A in insulinoma cells by botulinum neurotoxin C1 proteolysis followed by rescue with exogenous Syn-1A showed that Syn-1A modulates K(ATP) channel sensitivity to ATP. Thus, our data indicate that although both ATP and Syn-1A independently inhibit β-cell K(ATP) channel gating, they could also influence the sensitivity of K(ATP) channels to each other. These findings provide new insight into an alternate mechanism by which ATP regulates pancreatic β-cell K(ATP) channel activity, not only by its direct actions on Kir6.2 pore subunit, but also via ATP modulation of Syn-1A binding to SUR1.
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Affiliation(s)
- Youhou Kang
- Department of Medicine, University of Toronto and University Health Network, Toronto, Ontario M5S 1A8, Canada
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Leung YM, Tsou YH, Kuo CS, Lin SY, Wu PY, Hour MJ, Kuo YH. Arylnaphthalene lignans from Taiwania cryptomerioides as novel blockers of voltage-gated K+ channels. Phytomedicine 2010; 18:46-51. [PMID: 20684875 DOI: 10.1016/j.phymed.2010.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 03/19/2010] [Accepted: 04/01/2010] [Indexed: 05/29/2023]
Abstract
Lignans are natural phytochemicals which exhibit multiple pharmacological effects such as anti-inflammation, antivirus and anti-tumor activities. Whether they have effects on neural tissues and ion channels is still unknown. The effects of several arylnaphathalene lignans purified from Taiwania cryptomerioides on voltage-gated K(+) (Kv) channels in mouse neuroblastoma N2A cells were examined. These lignans included Taiwanin E, helioxanthin (HXT) and diphyllin. All lignans showed inhibitory effects on Kv channels and HXT was the most potent compound (IC(50)=1.7 μM). The mechanism of HXT block was further investigated. Its action was found to be extracellular but not intracellular. HXT accelerated current decay, caused a left-shift in steady-state inactivation curve but had no effect on voltage-dependence of activation. HXT block was unaffected by intracellular K(+) concentrations. Further, it did not affect ATP-sensitive K(+) channels. Our data therefore suggest that HXT is a potent and specific blocker of Kv channels, possibly with an inhibitory mechanism involving acceleration of slow inactivation.
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Affiliation(s)
- Yuk-Man Leung
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, Taiwan.
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Chao CC, Huang CC, Kuo CS, Leung YM. Control of ionic selectivity by a pore helix residue in the Kv1.2 channel. J Physiol Sci 2010; 60:441-6. [PMID: 20842544 PMCID: PMC10717328 DOI: 10.1007/s12576-010-0111-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [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: 06/27/2010] [Accepted: 08/24/2010] [Indexed: 10/19/2022]
Abstract
Interaction between the selectivity filter and the adjacent pore helix of voltage-gated K(+) (Kv) channels controls pore stability during K(+) conduction. Kv channels, having their selectivity filter destabilized during depolarization, are said to undergo C-type inactivation. We examined the functionality of a residue at the pore helix of the Kv1.2 channel (V370), which reportedly affects C-type inactivation. A mutation into glycine (V370G) caused a shift in reversal potential from around -72 to -9 mV. The permeability ratios (P(Na)/P(K)) of the wild type and V370G mutant are 0.04 and 0.76, respectively. In the wild-type, P(Rb)/P(K), P(Cs)/P(K) and P(Li)/P(K) are 0.78, 0.10 and 0.05, respectively. Kv1.2 V370G channels had enhanced permeability to Rb(+) and Cs(+) (P(Rb)/P(K) and P(Cs)/P(K) are 1.63 and 1.18, respectively); however, Li(+) permeability was not significantly augmented (P(Li)/P(K) is 0.13). Therefore, in addition to its known effect on pore stability, V370 of Kv1.2 is also crucial in controlling ion selectivity.
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Affiliation(s)
- Chia-Chia Chao
- Department of Life Sciences, National Chung Hsing University, Taichung, 402 Taiwan
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, 40402 Taiwan
| | - Chieh-Chen Huang
- Department of Life Sciences, National Chung Hsing University, Taichung, 402 Taiwan
| | - Chang-Shin Kuo
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, 40402 Taiwan
| | - Yuk-Man Leung
- Graduate Institute of Neural and Cognitive Sciences, China Medical University, Taichung, 40402 Taiwan
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