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Morse J, Nadiveedhi MR, Schmidt M, Tang FK, Hladun C, Ganesh P, Qiu Z, Leung K. Tunable Cytosolic Chloride Indicators for Real-Time Chloride Imaging in Live Cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.08.606814. [PMID: 39149292 PMCID: PMC11326291 DOI: 10.1101/2024.08.08.606814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Chloride plays a crucial role in various cellular functions, and its level is regulated by a variety of chloride transporters and channels. However, to date, we still lack the capability to image instantaneous ion flux through chloride channels at single-cell level. Here, we developed a series of cell-permeable, pH-independent, chloride-sensitive fluorophores for real-time cytosolic chloride imaging, which we call CytoCl dyes. We demonstrated the ability of CytoCl dyes to monitor cytosolic chloride and used it to uncover the rapid changes and transient events of halide flux, which cannot be captured by steady-state imaging. Finally, we successfully imaged the proton-activated chloride channel-mediated ion flux at single-cell level, which is, to our knowledge, the first real-time imaging of ion flux through a chloride channel in unmodified cells. By enabling the imaging of single-cell level ion influx through chloride channels and transporters, CytoCl dyes can expand our understanding of ion flux dynamics, which is critical for characterization and modulator screening of these membrane proteins. A conjugable version of CytoCl dyes was also developed for its customization across different applications.
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2
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Poz D, Crobu D, Sukhacheva E, Rocchi MBL, Anelli MC, Curcio F. Monocyte distribution width (MDW): a useful biomarker to improve sepsis management in Emergency Department. Clin Chem Lab Med 2022; 60:433-440. [PMID: 35001582 DOI: 10.1515/cclm-2021-0875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 12/29/2021] [Indexed: 12/19/2022]
Abstract
OBJECTIVES Sepsis is a time-dependent and life-threating condition. Despite several biomarkers are available, none of them is completely reliable for the diagnosis. This study aimed to evaluate the diagnostic utility of monocyte distribution width (MDW) to early detect sepsis in adult patients admitted in the Emergency Department (ED) with a five part differential analysis as part of the standard clinical practice. METHODS A prospective cohort study was conducted on 985 patients aged from 18 to 96 and included in the study between November 2019 and December 2019. Enrolled subjects were classified into four groups based on sepsis-2 diagnostic criteria: control, Systemic Inflammatory Response Syndrome (SIRS), infection and sepsis. The hematology analyzer DxH 900 (Beckman Coulter Inc.) provides the new reportable parameter MDW, included in the leukocyte 5 part differential analysis, cleared by Food and Drug administration (FDA) and European Community In-Vitro-Diagnostic Medical Device (CE IVD) marked as early sepsis indicator (ESId). RESULTS MDW was able to differentiate the sepsis group from all other groups with Area Under the Curve (AUC) of 0.849, sensitivity of 87.3% and specificity of 71.7% at cut-off of 20.1. MDW in combination with white blood cell (WBC) improves the performance for sepsis detection with a sensitivity increased up to 96.8% when at least one of the two biomarkers are abnormal, and a specificity increased up to 94.6% when both biomarkers are abnormal. CONCLUSIONS MDW can predict sepsis increasing the clinical value of Leukocyte 5 Part Differential analysis and supporting the clinical decision making in sepsis management at the admission to the ED.
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Affiliation(s)
- Donatella Poz
- Department of Laboratory Medicine, Institute of Clinical Pathology, University Hospital of Udine, Udine, Italy
| | | | | | - Marco Bruno Luigi Rocchi
- Department of Biomolecular Sciences, Service of Biostatistics, University of Urbino Carlo Bo, Urbino, Italy
| | | | - Francesco Curcio
- Department of Laboratory Medicine, Institute of Clinical Pathology, University Hospital of Udine, Udine, Italy.,Department of Medicine (DAME), University Hospital of Udine, Udine, Italy
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3
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Agnello L, Bivona G, Vidali M, Scazzone C, Giglio RV, Iacolino G, Iacona A, Mancuso S, Ciaccio AM, Lo Sasso B, Ciaccio M. Monocyte distribution width (MDW) as a screening tool for sepsis in the Emergency Department. Clin Chem Lab Med 2021; 58:1951-1957. [PMID: 32598299 DOI: 10.1515/cclm-2020-0417] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/19/2020] [Indexed: 01/03/2023]
Abstract
Objectives The diagnosis of sepsis in the Emergency Department (ED) is challenging and a reliable biomarker is needed. The current study aimed to evaluate the diagnostic accuracy of monocyte distribution width (MDW) for the early identification of sepsis in the ED. Methods We performed a large observational study including consecutive adult patients (≥18 years of age) presenting to the ED between September and November 2019, with an order for complete blood count (CBC) evaluation. A total of 2,215 patients were enrolled and classified based on Sepsis-2 criteria as the control group (1,855), infection group (172), Systemic Inflammatory Response Syndrome (SIRS) group (100), and sepsis group (88). Results MDW levels were higher in patients with sepsis than in all other groups (p<0.001). ROC curve analysis showed an optimal diagnostic accuracy of MDW for sepsis prediction at a cut-off point of 23.5, with an AUC of 0.964, sensitivity and specificity of 0.920 and 0.929, respectively. Conclusions Our findings encourage further investigation to validate the use of MDW as a screening tool for the early identification of patients at risk of sepsis in the ED.
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Affiliation(s)
- Luisa Agnello
- Institute of Clinical Biochemistry, Clinical Molecular Medicine and Laboratory Medicine, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | - Giulia Bivona
- Institute of Clinical Biochemistry, Clinical Molecular Medicine and Laboratory Medicine, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | - Matteo Vidali
- Unit of Clinical Chemistry, Maggiore della Carità Hospital, Novara, Italy
| | - Concetta Scazzone
- Institute of Clinical Biochemistry, Clinical Molecular Medicine and Laboratory Medicine, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | - Rosaria Vincenza Giglio
- Institute of Clinical Biochemistry, Clinical Molecular Medicine and Laboratory Medicine, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | - Giorgia Iacolino
- Institute of Clinical Biochemistry, Clinical Molecular Medicine and Laboratory Medicine, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | - Alessandro Iacona
- Institute of Clinical Biochemistry, Clinical Molecular Medicine and Laboratory Medicine, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | - Silvia Mancuso
- Institute of Clinical Biochemistry, Clinical Molecular Medicine and Laboratory Medicine, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | | | - Bruna Lo Sasso
- Institute of Clinical Biochemistry, Clinical Molecular Medicine and Laboratory Medicine, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy.,Department of Laboratory Medicine, AOUP "P. Giaccone", Palermo, Italy
| | - Marcello Ciaccio
- Institute of Clinical Biochemistry, Clinical Molecular Medicine and Laboratory Medicine, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy.,Department of Laboratory Medicine, AOUP "P. Giaccone", Palermo, Italy
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Monocyte Distribution Width, Neutrophil-to-Lymphocyte Ratio, and Platelet-to-Lymphocyte Ratio Improves Early Prediction for Sepsis at the Emergency. J Pers Med 2021; 11:jpm11080732. [PMID: 34442376 PMCID: PMC8402196 DOI: 10.3390/jpm11080732] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/24/2021] [Accepted: 07/27/2021] [Indexed: 12/19/2022] Open
Abstract
(1) Background: Sepsis is a life-threatening condition, and most patients with sepsis first present to the emergency department (ED) where early identification of sepsis is challenging due to the unavailability of an effective diagnostic model. (2) Methods: In this retrospective study, patients aged ≥20 years who presented to the ED of an academic hospital with systemic inflammatory response syndrome (SIRS) were included. The SIRS, sequential organ failure assessment (SOFA), and quick SOFA (qSOFA) scores were obtained for all patients. Routine complete blood cell testing in conjugation with the examination of new inflammatory biomarkers, namely monocyte distribution width (MDW), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR), was performed at the ED. Propensity score matching was performed between patients with and without sepsis. Logistic regression was used for constructing models for early sepsis prediction. (3) Results: We included 296 patients with sepsis and 1184 without sepsis. A SIRS score of >2, a SOFA score of >2, and a qSOFA score of >1 showed low sensitivity, moderate specificity, and limited diagnostic accuracy for predicting early sepsis infection (c-statistics of 0.660, 0.576, and 0.536, respectively). MDW > 20, PLR > 9, and PLR > 210 showed higher sensitivity and moderate specificity. When we combined these biomarkers and scoring systems, we observed a significant improvement in diagnostic performance (c-statistics of 0.796 for a SIRS score of >2, 0.761 for a SOFA score of >2, and 0.757 for a qSOFA score of >1); (4) Conclusions: The new biomarkers MDW, NLR, and PLR can be used for the early detection of sepsis in the current sepsis scoring systems.
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Wang Y, Xu Z, Zhou Y, Xie M, Qi X, Xu Z, Cai Q, Sheng H, Chen E, Zhao B, Mao E. Leukocyte cell population data from the blood cell analyzer as a predictive marker for severity of acute pancreatitis. J Clin Lab Anal 2021; 35:e23863. [PMID: 34062621 PMCID: PMC8274994 DOI: 10.1002/jcla.23863] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 05/11/2021] [Accepted: 05/16/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND The prediction for severe acute pancreatitis (SAP) is the key to give timely targeted treatment. Leukocyte cell population data (CPD) have been widely applied in early prediction and diagnosis of many diseases, but their predictive ability for SAP remains unexplored. We aim to testify whether CPD could be an indicator of AP severity in the early stage of the disease. METHODS The prospective observational study was conducted in the emergency department ward of a territory hospital in Shanghai. The enrolled AP patients should meet 2012 Atlanta guideline. RESULTS Totally, 103 AP patients and 62 healthy controls were enrolled and patients were classified into mild AP (n = 30), moderate SAP (n = 42), and SAP (n = 31). Forty-two CPD parameters were examined in first 3 days of admission. Four CPD parameters were highest in SAP on admission and were constantly different among 3 groups during first 3 days of hospital stay. Eighteen CPD parameters were found correlated with the occurrence of SAP. Stepwise multivariate logistic regression analysis identified a scoring system of 4 parameters (SD_LALS_NE, MN_LALS_LY, SD_LMALS_MO, and SD_AL2_MO) with a sensitivity of 96.8%, specificity of 65.3%, and AUC of 0.87 for diagnostic accuracy on early identification of SAP. AUC of this scoring system was comparable with MCTSI, SOFA, APACHE II, MMS, BISAP, or biomarkers as CRP, PCT, and WBC in prediction of SAP and ICU transfer or death. CONCLUSIONS Several leukocyte CPD parameters have been identified different among MAP, MSAP, and SAP. They might be ultimately incorporated into a predictive system marker for severity of AP.
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Affiliation(s)
- Yihui Wang
- Department of EmergencyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Zhihong Xu
- Department of EmergencyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Yuhua Zhou
- Department of EmergencyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Mengqi Xie
- Department of EmergencyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Xing Qi
- Department of EmergencyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Zhiwei Xu
- Department of General SurgeryPancreatic Disease CenterRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Qi Cai
- Department of Laboratory MedicineRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Huiqiu Sheng
- Department of EmergencyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Erzhen Chen
- Department of EmergencyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Bing Zhao
- Department of EmergencyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | - Enqiang Mao
- Department of EmergencyRuijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
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Monocyte Distribution Width: A Novel Indicator of Sepsis-2 and Sepsis-3 in High-Risk Emergency Department Patients. Crit Care Med 2020; 47:1018-1025. [PMID: 31107278 PMCID: PMC6629174 DOI: 10.1097/ccm.0000000000003799] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Supplemental Digital Content is available in the text. Objectives: Most septic patients are initially encountered in the emergency department where sepsis recognition is often delayed, in part due to the lack of effective biomarkers. This study evaluated the diagnostic accuracy of peripheral blood monocyte distribution width alone and in combination with WBC count for early sepsis detection in the emergency department. Design: An Institutional Review Board approved, blinded, observational, prospective cohort study conducted between April 2017 and January 2018. Setting: Subjects were enrolled from emergency departments at three U.S. academic centers. Patients: Adult patients, 18–89 years, with complete blood count performed upon presentation to the emergency department, and who remained hospitalized for at least 12 hours. A total of 2,212 patients were screened, of whom 2,158 subjects were enrolled and categorized per Sepsis-2 criteria, such as controls (n = 1,088), systemic inflammatory response syndrome (n = 441), infection (n = 244), and sepsis (n = 385), and Sepsis-3 criteria, such as control (n = 1,529), infection (n = 386), and sepsis (n = 243). Interventions: The primary outcome determined whether an monocyte distribution width of greater than 20.0 U, alone or in combination with WBC, improves early sepsis detection by Sepsis-2 criteria. Secondary endpoints determined monocyte distribution width performance for Sepsis-3 detection. Measurements and Main Results: Monocyte distribution width greater than 20.0 U distinguished sepsis from all other conditions based on either Sepsis-2 criteria (area under the curve, 0.79; 95% CI, 0.76–0.82) or Sepsis-3 criteria (area under the curve, 0.73; 95% CI, 0.69–0.76). The negative predictive values for monocyte distribution width less than or equal to 20 U for Sepsis-2 and Sepsis-3 were 93% and 94%, respectively. Monocyte distribution width greater than 20.0 U combined with an abnormal WBC further improved Sepsis-2 detection (area under the curve, 0.85; 95% CI, 0.83–0.88) and as reflected by likelihood ratio and added value analyses. Normal WBC and monocyte distribution width inferred a six-fold lower sepsis probability. Conclusions: An monocyte distribution width value of greater than 20.0 U is effective for sepsis detection, based on either Sepsis-2 criteria or Sepsis-3 criteria, during the initial emergency department encounter. In tandem with WBC, monocyte distribution width is further predicted to enhance medical decision making during early sepsis management in the emergency department.
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Guan YT, Xie Y, Zhou H, Shi HY, Zhu YY, Zhang XL, Luan Y, Shen XM, Chen YP, Xu LJ, Lin ZQ, Wang G. Overexpression of chloride channel-3 (ClC-3) is associated with human cervical carcinoma development and prognosis. Cancer Cell Int 2019; 19:8. [PMID: 30636929 PMCID: PMC6325671 DOI: 10.1186/s12935-018-0721-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 12/24/2018] [Indexed: 02/06/2023] Open
Abstract
Background Cervical carcinoma is a major gynecological cancer and causes cancer-related deaths in worldwide, the latent pathogenesis and progress of cervical cancer is still under research. ClC-3 may be an important promoter for aggressive metastasis of malignant tumors. In this research, we explore the ClC-3 expression in cervical carcinoma and its underlying clinical significance, trying to illuminate ClC-3 probable function in the neoplasm malignant behavior, development and prognosis. Methods Paraffin-embedded cervical (n = 168) and lymph node (n = 100) tissue specimens were analysed by immunohistochemistry. Fresh human cervical tissue specimens (n = 165) and four human cervical cell lines were tested for ClC-3 mRNA and protein expression levels by quantitative real-time PCR and western blotting. The relationship between the expression levels of ClC-3, the pathological characteristics of the carcinoma, and the clinical prognosis were statistically analysed. Results In normal and precancerous (LSIL, HSIL) cervical tissues as well as cervical carcinoma tissues, both ClC-3 mRNA and protein expression levels increased significantly (p < 0.05). The expression level of ClC-3 was closely-related to the histological differentiation (p = 0.029), tumour staging (p = 0.016), tumour size (p = 0.039), vascular invasion (p = 0.045), interstitial infiltration depth (p = 0.012), lymphatic metastasis (p = 0.036), and HPV infection (p = 0.022). In an in vitro experiment, ClC-3 mRNA and protein were found to be overexpressed both in the HeLa and SiHa cell lines, but low expression levels were detected in the C-33A and H8 cell lines (p < 0.05). Furthermore, the high expression levels of ClC-3 was significantly correlated to poor survival in cervical carcinoma patients (Log-rank test, p = 0.046). Conclusions These data suggest that overexpression of ClC-3 is closely associated with human cervical carcinoma progression and poor prognosis; this suggests that ClC-3 may function as a patent tumour biomarker and a latent therapeutic target for cervical carcinoma patients.
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Affiliation(s)
- Yu-Tao Guan
- 1Department of Obstetrics and Gynaecology, Sun Yat-sen Memorial Hospital of Sun Yat-Sen University, Guangzhou, China.,2Department of Obstetrics and Gynaecology, The First People's Hospital of Foshan, Foshan, China
| | - Yong Xie
- 2Department of Obstetrics and Gynaecology, The First People's Hospital of Foshan, Foshan, China
| | - Hui Zhou
- 1Department of Obstetrics and Gynaecology, Sun Yat-sen Memorial Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Hai-Yan Shi
- 3Department of Pathology, The First People's Hospital of Foshan, Foshan, China
| | - Yu-Yuan Zhu
- 2Department of Obstetrics and Gynaecology, The First People's Hospital of Foshan, Foshan, China
| | - Xiao-Lu Zhang
- 2Department of Obstetrics and Gynaecology, The First People's Hospital of Foshan, Foshan, China
| | - Yi Luan
- 1Department of Obstetrics and Gynaecology, Sun Yat-sen Memorial Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Xi-Ming Shen
- 4Department of Pathology, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Yang-Ping Chen
- 2Department of Obstetrics and Gynaecology, The First People's Hospital of Foshan, Foshan, China
| | - Li-Jiang Xu
- 2Department of Obstetrics and Gynaecology, The First People's Hospital of Foshan, Foshan, China
| | - Zhong-Qiu Lin
- 1Department of Obstetrics and Gynaecology, Sun Yat-sen Memorial Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Gang Wang
- 2Department of Obstetrics and Gynaecology, The First People's Hospital of Foshan, Foshan, China
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M De la Fuente I, Malaina I, Pérez-Samartín A, Boyano MD, Pérez-Yarza G, Bringas C, Villarroel Á, Fedetz M, Arellano R, Cortes JM, Martínez L. Dynamic properties of calcium-activated chloride currents in Xenopus laevis oocytes. Sci Rep 2017; 7:41791. [PMID: 28198817 PMCID: PMC5304176 DOI: 10.1038/srep41791] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 12/30/2016] [Indexed: 11/18/2022] Open
Abstract
Chloride is the most abundant permeable anion in the cell, and numerous studies in the last two decades highlight the great importance and broad physiological role of chloride currents mediated anion transport. They participate in a multiplicity of key processes, as for instance, the regulation of electrical excitability, apoptosis, cell cycle, epithelial secretion and neuronal excitability. In addition, dysfunction of Cl− channels is involved in a variety of human diseases such as epilepsy, osteoporosis and different cancer types. Historically, chloride channels have been of less interest than the cation channels. In fact, there seems to be practically no quantitative studies of the dynamics of chloride currents. Here, for the first time, we have quantitatively studied experimental calcium-activated chloride fluxes belonging to Xenopus laevis oocytes, and the main results show that the experimental Cl− currents present an informational structure characterized by highly organized data sequences, long-term memory properties and inherent “crossover” dynamics in which persistent correlations arise at short time intervals, while anti-persistent behaviors become dominant in long time intervals. Our work sheds some light on the understanding of the informational properties of ion currents, a key element to elucidate the physiological functional coupling with the integrative dynamics of metabolic processes.
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Affiliation(s)
- Ildefonso M De la Fuente
- Department of Nutrition, CEBAS-CSIC Institute, Espinardo University Campus, Murcia, Spain.,Department of Mathematics, Faculty of Science and Technology, University of the Basque Country, UPV/EHU, Leioa, Spain
| | - Iker Malaina
- Department of Mathematics, Faculty of Science and Technology, University of the Basque Country, UPV/EHU, Leioa, Spain
| | - Alberto Pérez-Samartín
- Department of Neurosciences, Faculty of Medicine and Dentistry, University of the Basque Country, UPV/EHU, Leioa, Spain
| | - María Dolores Boyano
- Department of Cell Biology and Histology, Faculty of Medicine and Dentistry, University of the Basque Country, UPV/EHU, Leioa, Spain
| | - Gorka Pérez-Yarza
- Department of Cell Biology and Histology, Faculty of Medicine and Dentistry, University of the Basque Country, UPV/EHU, Leioa, Spain
| | - Carlos Bringas
- Department of Cell Biology and Histology, Faculty of Medicine and Dentistry, University of the Basque Country, UPV/EHU, Leioa, Spain
| | - Álvaro Villarroel
- Biophysics Unit, CSIC, University of the Basque Country, UPV/EHU, Leioa, Spain
| | - María Fedetz
- Department of Biochemistry and Pharmacology, Institute of Parasitology and Biomedicine "López-Neyra", CSIC, Granada, Spain
| | - Rogelio Arellano
- Laboratory of Cellular Neurophysiology, Neurobiology Institute, UNAM, Querétaro, México
| | - Jesus M Cortes
- Department of Cell Biology and Histology, Faculty of Medicine and Dentistry, University of the Basque Country, UPV/EHU, Leioa, Spain.,BioCruces Health Research Institute, Cruces University Hospital, Barakaldo, Spain.,IKERBASQUE: The Basque Foundation for Science, Bilbao, Spain
| | - Luis Martínez
- Department of Mathematics, Faculty of Science and Technology, University of the Basque Country, UPV/EHU, Leioa, Spain
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Salao K, Jiang L, Li H, Tsai VWW, Husaini Y, Curmi PMG, Brown LJ, Brown DA, Breit SN. CLIC1 regulates dendritic cell antigen processing and presentation by modulating phagosome acidification and proteolysis. Biol Open 2016; 5:620-30. [PMID: 27113959 PMCID: PMC4874360 DOI: 10.1242/bio.018119] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Intracellular chloride channel protein 1 (CLIC1) participates in inflammatory processes by regulating macrophage phagosomal functions such as pH and proteolysis. Here, we sought to determine if CLIC1 can regulate adaptive immunity by actions on dendritic cells (DCs), the key professional antigen presenting cells. To do this, we first generated bone marrow-derived DCs (BMDCs) from germline CLIC1 gene-deleted (CLIC1−/−) and wild-type (CLIC1+/+) mice, then studied them in vitro and in vivo. We found phagocytosis triggered cytoplasmic CLIC1 translocation to the phagosomal membrane where it regulated phagosomal pH and proteolysis. Phagosomes from CLIC1−/− BMDCs displayed impaired acidification and proteolysis, which could be reproduced if CLIC1+/+, but not CLIC1−/− cells, were treated with IAA94, a CLIC family ion channel blocker. CLIC1−/− BMDC displayed reduced in vitro antigen processing and presentation of full-length myelin oligodendrocyte glycoprotein (MOG) and reduced MOG-induced experimental autoimmune encephalomyelitis. These data suggest that CLIC1 regulates DC phagosomal pH to ensure optimal processing of antigen for presentation to antigen-specific T-cells. Further, they indicate that CLIC1 is a novel therapeutic target to help reduce the adaptive immune response in autoimmune diseases. Summary: DC phagosomes from CLIC1−/− mice display impaired acidification and in vivo and in vitro antigen processing and presentation, revealing CLIC1−/− as a potential therapeutic target in reducing the adaptive immune response in autoimmune diseases.
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Affiliation(s)
- Kanin Salao
- St Vincent's Centre for Applied Medical Research, St. Vincent's Hospital and University of New South Wales, Sydney, New South Wales 2010, Australia
| | - Lele Jiang
- St Vincent's Centre for Applied Medical Research, St. Vincent's Hospital and University of New South Wales, Sydney, New South Wales 2010, Australia
| | - Hui Li
- St Vincent's Centre for Applied Medical Research, St. Vincent's Hospital and University of New South Wales, Sydney, New South Wales 2010, Australia
| | - Vicky W-W Tsai
- St Vincent's Centre for Applied Medical Research, St. Vincent's Hospital and University of New South Wales, Sydney, New South Wales 2010, Australia
| | - Yasmin Husaini
- St Vincent's Centre for Applied Medical Research, St. Vincent's Hospital and University of New South Wales, Sydney, New South Wales 2010, Australia
| | - Paul M G Curmi
- School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Louise J Brown
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - David A Brown
- St Vincent's Centre for Applied Medical Research, St. Vincent's Hospital and University of New South Wales, Sydney, New South Wales 2010, Australia
| | - Samuel N Breit
- St Vincent's Centre for Applied Medical Research, St. Vincent's Hospital and University of New South Wales, Sydney, New South Wales 2010, Australia
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Gaurav R, Bewtra AK, Agrawal DK. Chloride Channel 3 Channels in the Activation and Migration of Human Blood Eosinophils in Allergic Asthma. Am J Respir Cell Mol Biol 2015; 53:235-45. [PMID: 25514499 DOI: 10.1165/rcmb.2014-0300oc] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is responsible for respiratory burst in immune cells. Chloride channel 3 (CLC3) has been linked to the respiratory burst in eosinophils and neutrophils. The effect of cytokines and the involvement of CLC3 in the regulation of NADPH-dependent oxidative stress and on cytokine-mediated migration of eosinophils are not known. Human peripheral blood eosinophils were isolated from healthy individuals and from individuals with asthma by negative selection. Real-time PCR was used to detect the expression of NADPH oxidases in eosinophils. Intracellular reactive oxygen species (ROS) measurement was done with flow cytometry. Superoxide generation was measured with transforming growth factor (TGF)-β, eotaxin, and CLC3 blockers. CLC3 dependence of eosinophils in TGF-β- and eotaxin-induced migration was also examined. The messenger RNA (mRNA) transcripts of NADPH oxidase (NOX) 2, dual oxidase (DUOX) 1, and DUOX2 were detected in blood eosinophils, with very low expression of NOX1, NOX3, and NOX5 and no NOX4 mRNA. The level of NOX2 mRNA transcripts increased with disease severity in the eosinophils of subjects with asthma compared with healthy nonatopic volunteers. Change in granularity and size in eosinophils, but no change in intracellular ROS, was observed with phorbol myristate acetate (PMA). PMA, TGF-β, and eotaxin used the CLC3-dependent pathway to increase superoxide radicals. TGF-β and eotaxin induced CLC3-dependent chemotaxis of eosinophils. These findings support the requirement of CLC3 in the activation and migration of human blood eosinophils and may provide a potential novel therapeutic target to regulate eosinophil hyperactivity in allergic airway inflammation in asthma.
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Affiliation(s)
- Rohit Gaurav
- Department of Biomedical Sciences, Internal Medicine and Center of Clinical and Translational Sciences, Creighton University School of Medicine, Omaha, Nebraska
| | - Againdra K Bewtra
- Department of Biomedical Sciences, Internal Medicine and Center of Clinical and Translational Sciences, Creighton University School of Medicine, Omaha, Nebraska
| | - Devendra K Agrawal
- Department of Biomedical Sciences, Internal Medicine and Center of Clinical and Translational Sciences, Creighton University School of Medicine, Omaha, Nebraska
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Tao J, Liu CZ, Yang J, Xie ZZ, Ma MM, Li XY, Li FY, Wang GL, Zhou JG, Du YH, Guan YY. ClC-3 deficiency prevents atherosclerotic lesion development in ApoE−/− mice. J Mol Cell Cardiol 2015; 87:237-47. [DOI: 10.1016/j.yjmcc.2015.09.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 09/04/2015] [Accepted: 09/06/2015] [Indexed: 11/29/2022]
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12
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Shao Z, Gaurav R, Agrawal DK. Intermediate-conductance calcium-activated potassium channel KCa3.1 and chloride channel modulate chemokine ligand (CCL19/CCL21)-induced migration of dendritic cells. Transl Res 2015; 166:89-102. [PMID: 25583444 PMCID: PMC4458411 DOI: 10.1016/j.trsl.2014.11.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 10/31/2014] [Accepted: 11/15/2014] [Indexed: 01/12/2023]
Abstract
The role of ion channels is largely unknown in chemokine-induced migration in nonexcitable cells such as dendritic cells (DCs). Here, we examined the role of intermediate-conductance calcium-activated potassium channel (KCa3.1) and chloride channel (CLC3) in lymphatic chemokine-induced migration of DCs. The amplitude and kinetics of chemokine ligand (CCL19/CCL21)-induced Ca(2+) influx were associated with chemokine receptor 7 expression levels, extracellular-free Ca(2+) and Cl(-), and independent of extracellular K(+). Chemokines (CCL19 and CCL21) and KCa3.1 activator (1-ethyl-1,3-dihydro-2H-benzimidazol-2-one) induced plasma membrane hyperpolarization and K(+) efflux, which was blocked by 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole, suggesting that KCa3.1 carried larger conductance than the inward calcium release-activated calcium channel. Blockade of KCa3.1, low Cl(-) in the medium, and low dose of 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) impaired CCL19/CCL21-induced Ca(2+) influx, cell volume change, and DC migration. High doses of DIDS completely blocked DC migration possibly by significantly disrupting mitochondrial membrane potential. In conclusion, KCa3.1 and CLC3 are critical in human DC migration by synergistically regulating membrane potential, chemokine-induced Ca(2+) influx, and cell volume.
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Affiliation(s)
- Zhifei Shao
- Center for Clinical and Translational Science, Creighton University of School of Medicine, Omaha, Neb
| | - Rohit Gaurav
- Center for Clinical and Translational Science, Creighton University of School of Medicine, Omaha, Neb
| | - Devendra K Agrawal
- Center for Clinical and Translational Science, Creighton University of School of Medicine, Omaha, Neb.
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Gaurav R, Bewtra AK, Agrawal DK. Novel CLC3 transcript variants in blood eosinophils and increased CLC3 expression in nasal lavage and blood eosinophils of asthmatics. IMMUNITY INFLAMMATION AND DISEASE 2014; 2:205-13. [PMID: 25866628 PMCID: PMC4386915 DOI: 10.1002/iid3.36] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 09/11/2014] [Accepted: 09/12/2014] [Indexed: 01/21/2023]
Abstract
Eosinophilia is a characteristic feature of allergic airway inflammation and remodeling. Chloride channel-3 (CLC3) in eosinophils has been associated with superoxide generation and respiratory burst. The CLC3 gene may produce multiple transcript variants through alternative splicing. However, the presence of CLC3 variants in human eosinophils is unknown. We examined the expression of CLC3 transcript variants in peripheral blood eosinophils of allergic asthmatics and healthy individuals. Potential of these obligatory dimers to form homo- or hetero-dimers was examined in HEK293 cells co-transfected with CLC3b-GFP and CLC3e-RFP. Eosinophils were isolated from peripheral blood by negative selection. Expression of CLC3 and CLC3 transcript variants was examined by qPCR, Western blot, and immunofluorescence. Confocal micrographs were analyzed with Image J software. Higher levels of novel transcript variants of CLC3 (CLC3b and CLC3e) were found in peripheral blood eosinophils of asthmatics compared to healthy non-atopic subjects. We also found higher CLC3 protein expression in the blood and nasal lavage eosinophils of asthmatics than healthy subjects. Both membranous and intracellular CLC3 expression were observed. Also, we found the presence of both homodimers and heterodimers of CLC3b-GFP and CLC3e-RFP in HEK293 cells. Higher and differential expression of novel CLC3 transcript variants in mild-to-moderate and moderate-to-severe asthmatic eosinophils suggest their critical role in allergic asthma. Membranous and intracellular (granular) expression of CLC3 in nasal lavage and peripheral blood eosinophils suggest their involvement in the activation and migration of eosinophils in allergic asthma. Moreover, homo- and hetero-dimerization of these transcript variants may change the channel properties to exhibit these states. Presence of CLC3 variants may serve as a biomarker in allergic asthma and additional knowledge of interaction between CLC3 transcript variants and their specific role in the activation and migration of eosinophils will allow to explore novel therapeutic approach in allergic asthma.
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Affiliation(s)
- Rohit Gaurav
- Center of Clinical and Translational Sciences and Department of Biomedical Sciences, Creighton University School of Medicine Omaha, Nebraska
| | - Againdra K Bewtra
- Center of Clinical and Translational Sciences and Department of Biomedical Sciences, Creighton University School of Medicine Omaha, Nebraska
| | - Devendra K Agrawal
- Center of Clinical and Translational Sciences and Department of Biomedical Sciences, Creighton University School of Medicine Omaha, Nebraska
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14
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Electrophysiological evaluation of Cystic Fibrosis Conductance Transmembrane Regulator (CFTR) expression in human monocytes. Biochim Biophys Acta Gen Subj 2014; 1840:3088-95. [DOI: 10.1016/j.bbagen.2014.07.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 06/30/2014] [Accepted: 07/14/2014] [Indexed: 12/31/2022]
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15
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Stock C, Ludwig FT, Hanley PJ, Schwab A. Roles of ion transport in control of cell motility. Compr Physiol 2013; 3:59-119. [PMID: 23720281 DOI: 10.1002/cphy.c110056] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell motility is an essential feature of life. It is essential for reproduction, propagation, embryonic development, and healing processes such as wound closure and a successful immune defense. If out of control, cell motility can become life-threatening as, for example, in metastasis or autoimmune diseases. Regardless of whether ciliary/flagellar or amoeboid movement, controlled motility always requires a concerted action of ion channels and transporters, cytoskeletal elements, and signaling cascades. Ion transport across the plasma membrane contributes to cell motility by affecting the membrane potential and voltage-sensitive ion channels, by inducing local volume changes with the help of aquaporins and by modulating cytosolic Ca(2+) and H(+) concentrations. Voltage-sensitive ion channels serve as voltage detectors in electric fields thus enabling galvanotaxis; local swelling facilitates the outgrowth of protrusions at the leading edge while local shrinkage accompanies the retraction of the cell rear; the cytosolic Ca(2+) concentration exerts its main effect on cytoskeletal dynamics via motor proteins such as myosin or dynein; and both, the intracellular and the extracellular H(+) concentration modulate cell migration and adhesion by tuning the activity of enzymes and signaling molecules in the cytosol as well as the activation state of adhesion molecules at the cell surface. In addition to the actual process of ion transport, both, channels and transporters contribute to cell migration by being part of focal adhesion complexes and/or physically interacting with components of the cytoskeleton. The present article provides an overview of how the numerous ion-transport mechanisms contribute to the various modes of cell motility.
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Affiliation(s)
- Christian Stock
- Institute of Physiology II, University of Münster, Münster, Germany.
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16
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Schwab A, Fabian A, Hanley PJ, Stock C. Role of ion channels and transporters in cell migration. Physiol Rev 2013; 92:1865-913. [PMID: 23073633 DOI: 10.1152/physrev.00018.2011] [Citation(s) in RCA: 315] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cell motility is central to tissue homeostasis in health and disease, and there is hardly any cell in the body that is not motile at a given point in its life cycle. Important physiological processes intimately related to the ability of the respective cells to migrate include embryogenesis, immune defense, angiogenesis, and wound healing. On the other side, migration is associated with life-threatening pathologies such as tumor metastases and atherosclerosis. Research from the last ≈ 15 years revealed that ion channels and transporters are indispensable components of the cellular migration apparatus. After presenting general principles by which transport proteins affect cell migration, we will discuss systematically the role of channels and transporters involved in cell migration.
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Abstract
Malignant gliomas are highly invasive brain tumors that currently lack effective treatment. Unlike other cancers, gliomas do not metastasize via the vasculature but invade surrounding brain solely along extracellular routes, primarily moving along the vasculature and nerve tracts. This study uses several model systems to visualize and quantitatively assess cell volume changes of human glioma cells invading within the brain's extracellular space of C.B.17 severe combined immunodeficient (scid) mice and tumor cells invading in a modified Boyden chamber using three-dimensional multiphoton and confocal time-lapse microscopy. Regardless of model system used to quantitatively assess volume changes, invading glioma cells maximally decreased their volume by 30-35%, a value that was independent of barrier and cell size. Through osmotic challenges, we demonstrate that the observed cellular volume changes during invasion represent the smallest achievable cell volume and require glioma cells to release all free unbound cytoplasmic water. Water osmotically follows the release of Cl(-) through ion channels and cotransporters and blockade of Cl(-) flux inhibits both volume changes and cell invasion. Hence, invading glioma cells use hydrodynamic volume changes to meet the spatial constraints imposed within the brain, using essentially all free, unbound cytoplasmic water to maximally alter their volume as they invade.
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18
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Schlichter LC, Mertens T, Liu B. Swelling activated Cl- channels in microglia: Biophysics, pharmacology and role in glutamate release. Channels (Austin) 2011; 5:128-37. [PMID: 21150294 DOI: 10.4161/chan.5.2.14310] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Microglia have a swelling-activated Cl- current (which we call IClswell), and while some of its biophysical properties and functional roles have been elucidated, its molecular identity is unknown. To relate this current to cell functions and determine whether it is regulated by mechanisms other than cell swelling, it is important to establish both biophysical and pharmacological fingerprints. Here, we used rat microglia and a cell line derived from them (MLS-9) to study biophysical, regulatory and pharmacological properties of IClswell. The whole-cell current was activated in response to a hypo-osmotic bath solution, but not by voltage, and was time-independent during long voltage steps. The halide selectivity sequence was I->Br->Cl- (Eisenman sequence I) and importantly, the excitatory amino acid, glutamate was permeant. Current activation required internal ATP, and was not affected by the guanine nucleotides, GTPS or GDPS, or physiological levels of internal Mg2+. The same current was activated by a low intracellular ionic strength solution without an osmotic gradient. IClswell was reversibly inhibited by known Cl- channel blockers (NPPB, flufenamic acid, glibenclamide, DCPIB), and by the glutamate release inhibitor, riluzole. Cell swelling evoked glutamate release from primary microglia and MLS-9 cells, and this was inhibited by the blockers (above), and by IAA-94, but not by tamoxifen or the Na+/K+/Cl- symport inhibitor, bumetanide. Together, these results confirm the similarity of IClswell in the two cell types, and point to a role for this channel in inflammation-mediated glutamate release in the CNS.
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Affiliation(s)
- Lyanne C Schlichter
- Toronto Western Research Institute, University Health Network, Department of Physiology, University of Toronto, Toronto, Ontario, Canada.
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19
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Trettel F, Di Angelantonio S, Limatola C, Ransohoff RM. Chemokines and chemokine receptors in the nervous system Rome, 24/25 October, 2009, 2nd workshop. J Neuroimmunol 2010; 224:1-7. [DOI: 10.1016/j.jneuroim.2010.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2010] [Accepted: 05/04/2010] [Indexed: 11/28/2022]
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20
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Eder C. Ion channels in monocytes and microglia / brain macrophages: Promising therapeutic targets for neurological diseases. J Neuroimmunol 2010; 224:51-5. [DOI: 10.1016/j.jneuroim.2010.05.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Accepted: 05/04/2010] [Indexed: 10/19/2022]
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21
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Schilling T, Eder C. Lysophosphatidylcholine- and MCP-1-induced chemotaxis of monocytes requires potassium channel activity. Pflugers Arch 2009; 459:71-7. [PMID: 19680683 DOI: 10.1007/s00424-009-0710-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 07/29/2009] [Accepted: 08/01/2009] [Indexed: 11/25/2022]
Abstract
One of the earliest cellular responses in atherogenesis is the focal recruitment of circulating monocytes, while the most important atherogenic chemoattractants are monocyte chemoattractant protein-1 (MCP-1) and lysophosphatidylcholine (LPC). Invading monocytes transform into activated macrophages and foam cells, which stimulate inflammatory processes and promote atherosclerosis. In this study, we have searched for common mechanisms involved in MCP-1- and LPC-stimulated monocyte migration. We have found that migration of THP-1 monocytes stimulated with MCP-1 was reduced upon inhibition of G(i/o) proteins with pertussis toxin and upon inhibition of platelet activating factor receptors with BN52021, whereas LPC-stimulated monocyte chemotaxis remained unaffected by both inhibitors. Furthermore, Cl(-) channels were only required for MCP-1-induced chemotaxis. However, activity of voltage-gated K+ channels and of Ca2+-activated K+ channels was found to be involved in migration of monocytes stimulated with either MCP-1 or LPC. Inhibition of voltage-gated K+ channels with 4-aminopyridine or margatoxin partially inhibited MCP-1- and LPC-stimulated migration of monocytes. Blockade of Ca2+-activated K+ channels with TRAM-34 also partially reduced migration of MCP-1- and LPC-stimulated monocytes. Simultaneous inhibition of voltage-gated and Ca2+-activated K+ channels abolished MCP-1- and LPC-induced chemotaxis of monocytes. Thus, K+ channel inhibition may represent a novel powerful strategy to reduce monocyte infiltration and subsequent inflammation in atherosclerosis.
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Affiliation(s)
- Tom Schilling
- Division of Basic Medical Sciences, St. George's University of London, Cranmer Terrace, London, SW17 0RE, UK
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22
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Kjaer K, Strøbaek D, Christophersen P, Rønn LCB. Chloride channel blockers inhibit iNOS expression and NO production in IFNgamma-stimulated microglial BV2 cells. Brain Res 2009; 1281:15-24. [PMID: 19446535 DOI: 10.1016/j.brainres.2009.05.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Revised: 03/13/2009] [Accepted: 05/02/2009] [Indexed: 01/25/2023]
Abstract
Microglial cells play an important role during neuroinflammation in the central nervous system. Among other factors, activated microglia produce nitric oxide (NO), which is toxic to neurons and excessive microglial activation and NO production contribute to the pathology of neurodegenerative diseases. Chloride channels have previously been shown to participate in microglial activation. Here we investigate the effects of established chloride channel blockers with different chemical structures on interferon-gamma (IFNgamma)-induced activation of the murine microglial cell line, BV2. IFNgamma-induced NO production was effectively reduced by NPPB, IAA-94, tamoxifen, NS3728 and NS1652, with NS1652 being the most potent. In contrast, DIDS reduced NO production only at cytotoxic concentrations. Furthermore, NS1652 reduced the protein and mRNA levels of inducible nitric oxide synthase (iNOS), without altering STAT1 phosphorylation. These observations suggest a microglial chloride conductance as a critical permissive factor downstream in the IFNgamma-induced iNOS cascade. The nature of the underlying channel is unknown, but the pharmacological profile appears incompatible with the involvement of the volume activated anion conductance (VRAC).
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Affiliation(s)
- Katrine Kjaer
- NeuroSearch A/S, Pederstrupvej 93, Ballerup, Denmark
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23
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Volk APD, Heise CK, Hougen JL, Artman CM, Volk KA, Wessels D, Soll DR, Nauseef WM, Lamb FS, Moreland JG. ClC-3 and IClswell are required for normal neutrophil chemotaxis and shape change. J Biol Chem 2008; 283:34315-26. [PMID: 18840613 DOI: 10.1074/jbc.m803141200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Polymorphonuclear leukocytes undergo directed movement to sites of infection, a complex process known as chemotaxis. Extension of the polymorphonuclear leukocyte (PMN) leading edge toward a chemoattractant in association with uropod retraction must involve a coordinated increase/decrease in membrane, redistribution of cell volume, or both. Deficits in PMN phagocytosis and trans-endothelial migration, both highly motile PMN functions, suggested that the anion transporters, ClC-3 and ICl(swell), are involved in cell motility and shape change ( Moreland, J. G., Davis, A. P., Bailey, G., Nauseef, W. M., and Lamb, F. S. (2006) J. Biol. Chem. 281, 12277-12288 ). We hypothesized that ClC-3 and ICl(swell) are required for normal PMN chemotaxis through regulation of cell volume and shape change. Using complementary chemotaxis assays, EZ-TAXIScantrade mark and dynamic imaging analysis software, we analyzed the directed cell movement and morphology of PMNs lacking normal anion transporter function. Murine Clcn3(-/-) PMNs and human PMNs treated with anion transporter inhibitors demonstrated impaired chemotaxis in response to formyl peptide. This included decreased cell velocity and failure to undergo normal cycles of elongation and retraction. Impaired chemotaxis was not due to a diminished number of formyl peptide receptors in either murine or human PMNs, as measured by flow cytometry. Murine Clcn3(-/-) and Clcn3(+/+) PMNs demonstrated a similar regulatory volume decrease, indicating that the ICl(swell) response to hypotonic challenge was intact in these cells. We further demonstrated that ICl(swell) is essential for shape change during human PMN chemotaxis. We speculate that ClC-3 and ICl(swell) have unique roles in regulation of PMN chemotaxis; ICl(swell) through direct effects on PMN volume and ClC-3 through regulation of ICl(swell).
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Affiliation(s)
- A Paige Davis Volk
- Department of Pediatrics, W.M. Keck Dynamic Image Analysis Facility, University of Iowa College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
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24
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Hartzell HC, Qu Z, Yu K, Xiao Q, Chien LT. Molecular physiology of bestrophins: multifunctional membrane proteins linked to best disease and other retinopathies. Physiol Rev 2008; 88:639-72. [PMID: 18391176 DOI: 10.1152/physrev.00022.2007] [Citation(s) in RCA: 256] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This article reviews the current state of knowledge about the bestrophins, a newly identified family of proteins that can function both as Cl(-) channels and as regulators of voltage-gated Ca(2+) channels. The founding member, human bestrophin-1 (hBest1), was identified as the gene responsible for a dominantly inherited, juvenile-onset form of macular degeneration called Best vitelliform macular dystrophy. Mutations in hBest1 have also been associated with a small fraction of adult-onset macular dystrophies. It is proposed that dysfunction of bestrophin results in abnormal fluid and ion transport by the retinal pigment epithelium, resulting in a weakened interface between the retinal pigment epithelium and photoreceptors. There is compelling evidence that bestrophins are Cl(-) channels, but bestrophins remain enigmatic because it is not clear that the Cl(-) channel function can explain Best disease. In addition to functioning as a Cl(-) channel, hBest1 also is able to regulate voltage-gated Ca(2+) channels. Some bestrophins are activated by increases in intracellular Ca(2+) concentration, but whether bestrophins are the molecular counterpart of Ca(2+)-activated Cl(-) channels remains in doubt. Bestrophins are also regulated by cell volume and may be a member of the volume-regulated anion channel family.
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Affiliation(s)
- H Criss Hartzell
- Department of Cell Biology, Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
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25
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Chien LT, Hartzell HC. Drosophila bestrophin-1 chloride current is dually regulated by calcium and cell volume. ACTA ACUST UNITED AC 2008; 130:513-24. [PMID: 17968025 PMCID: PMC2151665 DOI: 10.1085/jgp.200709795] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mutations in the human bestrophin-1 (hBest1) gene are responsible for Best vitelliform macular dystrophy, however the mechanisms leading to retinal degeneration have not yet been determined because the function of the bestrophin protein is not fully understood. Bestrophins have been proposed to comprise a new family of Cl(-) channels that are activated by Ca(2+). While the regulation of bestrophin currents has focused on intracellular Ca(2+), little is known about other pathways/mechanisms that may also regulate bestrophin currents. Here we show that Cl(-) currents in Drosophila S2 cells, that we have previously shown are mediated by bestrophins, are dually regulated by Ca(2+) and cell volume. The bestrophin Cl(-) currents were activated in a dose-dependent manner by osmotic pressure differences between the internal and external solutions. The increase in the current was accompanied by cell swelling. The volume-regulated Cl(-) current was abolished by treating cells with each of four different RNAi constructs that reduced dBest1 expression. The volume-regulated current was rescued by transfecting with dBest1. Furthermore, cells not expressing dBest1 were severely depressed in their ability to regulate their cell volume. Volume regulation and Ca(2+) regulation can occur independently of one another: the volume-regulated current was activated in the complete absence of Ca(2+) and the Ca(2+)-activated current was activated independently of alterations in cell volume. These two pathways of bestrophin channel activation can interact; intracellular Ca(2+) potentiates the magnitude of the current activated by changes in cell volume. We conclude that in addition to being regulated by intracellular Ca(2+), Drosophila bestrophins are also novel members of the volume-regulated anion channel (VRAC) family that are necessary for cell volume homeostasis.
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Affiliation(s)
- Li-Ting Chien
- Department of Cell Biology, Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA 30322, USA
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Zierler S, Frei E, Grissmer S, Kerschbaum HH. Chloride Influx Provokes Lamellipodium Formation in Microglial Cells. Cell Physiol Biochem 2008; 21:55-62. [DOI: 10.1159/000113747] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2007] [Indexed: 11/19/2022] Open
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Agrawal DK, Cheng G, Kim MJ, Kiniwa M. Interaction of suplatast tosilate (IPD) with chloride channels in human blood eosinophils: a potential mechanism underlying its anti-allergic and anti-asthmatic effects. Clin Exp Allergy 2007; 38:305-12. [PMID: 18028459 DOI: 10.1111/j.1365-2222.2007.02877.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
INTRODUCTION Alterations in chloride ion channels have been implicated in the induction of changes in cell shape and volume. Because blood and tissue eosinophilia are hallmarks of bronchial asthma, in this study we examined the role of chloride channels in the underlying effects of suplatast tosilate (IPD), an anti-allergic drug, in human blood eosinophils. METHODS Eosinophils were isolated and purified from the blood of allergic asthmatic donors. Chloride ion currents were recorded using the whole-cell patch-clamp technique in freshly isolated eosinophils. The current-voltage relationship of whole-cell currents in human blood eosinophils was calculated and recorded. The effect of chloride channel blockers was examined on superoxide release, eosinophil chemotaxis as measured by the Boyden chamber, and eosinophil adhesion to endothelial cells. Radioligand binding studies with [3H]IPD and competition curves with chloride channel blockers were performed. RESULTS IPD increased both inward and outward chloride currents in human blood eosinophils. IPD in 1 ng/mL did not have significant effect on chloride current. However, at 5 ng/mL IPD activated both outward and inward currents in human blood eosinophils. Chloride channel blockers inhibited IPD-induced respiratory burst in eosinophils, eosinophil chemotaxis, and eosinophil adhesion to endothelial cells. All these effects of IPD on chloride current and the resultant functional responses in human blood eosinophils were not due to its basic salt, p-toluenesulphonic acid monohydrate. Human blood eosinophils contained specific binding sites for [3H]IPD with K(D) and B(max) values of 187.7+/-105.8 nm and 58.7+/-18.7 fmol/10(6) cells, respectively. Both NPPB and DIDS competed, in a dose-dependent manner, for the specific binding of [3H]IPD in human blood eosinophils. CONCLUSION These data suggest that the anti-allergic and anti-asthmatic effects of IPD could be due to its interaction with chloride channels in human blood eosinophils.
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Affiliation(s)
- D K Agrawal
- Creighton University School of Medicine, Omaha, NE 68178, USA.
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28
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Ducharme G, Newell EW, Pinto C, Schlichter LC. Small-conductance Cl- channels contribute to volume regulation and phagocytosis in microglia. Eur J Neurosci 2007; 26:2119-30. [PMID: 17927776 DOI: 10.1111/j.1460-9568.2007.05802.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The shape and volume of microglia (brain immune cells) change when they activate during brain inflammation and become migratory and phagocytic. Swollen rat microglia express a large Cl(-) current (I(Clswell)), whose biophysical properties and functional roles are poorly understood and whose molecular identity is unknown. We constructed a fingerprint of useful biophysical properties for comparison with I(Clswell) in other cell types and with cloned Cl(-) channels. The microglial I(Clswell) was rapidly activated by cell swelling but not by voltage, and showed no time-dependence during voltage-clamp steps. Like I(Clswell) in many cell types, the halide selectivity sequence was I(-) > Br(-) > Cl(-) > F(-). However, it differed in lacking inactivation, even at +100 mV with high extracellular Mg(2+), and in having a much lower single-channel conductance: 1-3 pS. Based on these fundamental differences, the microglia channel is apparently a different gene product than the more common intermediate-conductance I(Clswell). Microglia express several candidate genes, with relative mRNA expression levels of: CLIC1 > ClC3 > I(Cln) > or = ClC2 > Best2 > Best1 > or = Best3 > Best4. Using a pharmacological toolbox, we show that all drugs that reduced the microglia current (NPPB, IAA-94, flufenamic acid and DIOA) increased the resting cell volume in isotonic solution and inhibited the regulatory volume decrease that followed cell swelling in hypotonic solution. Both channel blockers tested (NPPB and flufenamic acid) dose-dependently inhibited microglia phagocytosis of E. coli bacteria. Because I(Clswell) is involved in microglia functions that involve shape and volume changes, it is potentially important for controlling their ability to migrate to damage sites and phagocytose dead cells and debris.
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Affiliation(s)
- Guillaume Ducharme
- Toronto Western Research Institute, University Health Network, University of Toronto, Toronto, Ontario, Canada M5T 2S8
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29
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Cheng G, Shao Z, Chaudhari B, Agrawal DK. Involvement of chloride channels in TGF-beta1-induced apoptosis of human bronchial epithelial cells. Am J Physiol Lung Cell Mol Physiol 2007; 293:L1339-47. [PMID: 17873007 DOI: 10.1152/ajplung.00121.2007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Widespread damage of airway epithelium and defective epithelial repair are hallmarks of chronic asthma. Growth factors and cytokines spatially and temporally regulate epithelial shedding and repair. Within this context, a key function is exerted by transforming growth factor (TGF)-beta. Recent growing evidence suggests that chloride (Cl(-)) channels are critical to cell apoptosis. We examined the effects of TGF-beta1 on Cl(-) channel expression and activity and its relationship with apoptosis in human bronchial epithelial cells (HBECs). The small interfering RNA (siRNA) approach was used to investigate the potential role of CLC-3, a member of the volume-regulated Cl(-) channel family, in apoptosis of HBECs. TGF-beta1 significantly induced HBEC apoptosis, which paralleled to a significant decrease in the endogenous expression of CLC-3 protein and mRNA transcripts. Outward rectifying and voltage-dependent CLC-3-like Cl(-) currents in HBECs were diminished by TGF-beta1. siRNA for CLC-3 abolished Cl(-) current and enhanced TGF-beta1-induced cell apoptosis. Overexpression of CLC-3 in HBECs inhibited TGF-beta1-induced cell apoptosis. Bcl-2 was also downregulated after TGF-beta stimulation. TGF-beta1-induced cell apoptosis was suppressed in Bcl-2-transfected HBECs. Our data demonstrate that CLC-3-like voltage-gated chloride channels play a critical role in TGF-beta-induced apoptosis of human airway epithelial cells.
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Affiliation(s)
- Gang Cheng
- Department of Biomedical Sciences, Creighton Univ. School of Medicine, CRISS II Rm. 510, 2500 California Plaza, Omaha, NE 68178, USA
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Schwab A, Nechyporuk-Zloy V, Fabian A, Stock C. Cells move when ions and water flow. Pflugers Arch 2006; 453:421-32. [PMID: 17021798 DOI: 10.1007/s00424-006-0138-6] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Accepted: 07/09/2006] [Indexed: 12/22/2022]
Abstract
Cell migration is a process that plays an important role throughout the entire life span. It starts early on during embryogenesis and contributes to shaping our body. Migrating cells are involved in maintaining the integrity of our body, for instance, by defending it against invading pathogens. On the other side, migration of tumor cells may have lethal consequences when tumors spread metastatically. Thus, there is a strong interest in unraveling the cellular mechanisms underlying cell migration. The purpose of this review is to illustrate the functional importance of ion and water channels as part of the cellular migration machinery. Ion and water flow is required for optimal migration, and the inhibition or genetic ablation of channels leads to a marked impairment of migration. We briefly touch cytoskeletal mechanisms of migration as well as cell-matrix interactions. We then present some general principles by which channels can affect cell migration before we discuss each channel group separately.
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Affiliation(s)
- Albrecht Schwab
- Institut für Physiologie II, Universität Münster, Robert-Koch-Str. 27b, 48149, Münster, Germany.
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