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Iglesias-Martínez-Almeida M, Campos-Ríos A, Freiría-Martínez L, Rivera-Baltanás T, Rodrígues-Amorím D, Diz-Chaves Y, Comis-Tuche M, Fernández-Palleiro P, Rodríguez-Jamardo C, Ramos-García S, Rodríguez-Tébar A, Del Carmen Vallejo-Curto M, Campos-Pérez JA, López-García M, de Las Heras E, García-Caballero A, Olivares JM, Lamas JA, Spuch C. Characterization and modulation of voltage-gated potassium channels in human lymphocytes in schizophrenia. Schizophr Res 2024; 270:260-272. [PMID: 38944972 DOI: 10.1016/j.schres.2024.06.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 06/20/2024] [Accepted: 06/22/2024] [Indexed: 07/02/2024]
Abstract
BACKGROUND It is known that the immune system is dysregulated in schizophrenia, having a state similar to chronic neuroinflammation. The origin of this process is unknown, but it is known that T and B lymphocytes, which are components of the adaptive immune system, play an important role in the pathogenic mechanisms of schizophrenia. METHODS We analysed the membrane of PBMCs from patients diagnosed with schizophrenia through proteomic analysis (n = 5 schizophrenia and n = 5 control). We found the presence of the Kv1.3 voltage-gated potassium channel and its auxiliary subunit β1 (KCNAB1) and β2 (KCNAB2). From a sample of 90 participants, we carried out a study on lymphocytes with whole-cell patch-clamp experiments (n = 7 schizophrenia and n = 5 control), western blot (n = 40 schizophrenia and n = 40 control) and confocal microscopy to evaluate the presence and function of different channels. Kv in both cells. RESULTS We demonstrated the overexpression of Kv1.1, Kv1.2, Kv1.3, Kv1.6, Kv4.2, Kv4.3 and Kv7.2 channels in PBMCs from patients with schizophrenia. This study represents a groundbreaking exploration, as it involves an electrophysiological analysis performed on T and B lymphocytes from patients diagnosed of schizophrenia compared to healthy participants. We observed that B lymphocytes exhibited an increase in output current along with greater peak current amplitude and voltage conductance curves among patients with schizophrenia compared with healthy controls. CONCLUSIONS This study showed the importance of the B lymphocyte in schizophrenia. We know that the immune system is altered in schizophrenia, but the physiological mechanisms of this system are not very well known. We suggest that the B lymphocyte may be relevant in the pathophysiology of schizophrenia and that it should be investigated in more depth, opening a new field of knowledge and possibilities for new treatments combining antipsychotics and immunomodulators. The limitation is that all participants received antipsychotic medication, which may have influenced the differences observed between patients and controls. This implies that more studies need to be done where the groups can be separated according to the antipsychotic drug.
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Affiliation(s)
- Marta Iglesias-Martínez-Almeida
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain; University of Vigo, Vigo, Spain
| | - Ana Campos-Ríos
- Laboratory of neuroscience, University of Vigo, Department of Functional Biology and Health Sciences, Vigo, Spain; Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), SERGAS-UVIGO, Vigo, Spain
| | - Luis Freiría-Martínez
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain; University of Vigo, Vigo, Spain
| | - Tania Rivera-Baltanás
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain; University of Vigo, Vigo, Spain; CIBERSAM, Madrid, Spain
| | - Daniela Rodrígues-Amorím
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, United States
| | | | - María Comis-Tuche
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | - Patricia Fernández-Palleiro
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | - Cynthia Rodríguez-Jamardo
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain; University of Vigo, Vigo, Spain
| | - Silvia Ramos-García
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | | | | | - Jose Antonio Campos-Pérez
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | - Marta López-García
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | - Elena de Las Heras
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | - Alejandro García-Caballero
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | - Jose M Olivares
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain; CIBERSAM, Madrid, Spain
| | - Jose A Lamas
- Laboratory of neuroscience, University of Vigo, Department of Functional Biology and Health Sciences, Vigo, Spain; Laboratory of Neuroscience, Galicia Sur Health Research Institute (IISGS), SERGAS-UVIGO, Vigo, Spain
| | - Carlos Spuch
- Translational Neuroscience Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain; CIBERSAM, Madrid, Spain.
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Navarro-Pérez M, Capera J, Benavente-Garcia A, Cassinelli S, Colomer-Molera M, Felipe A. Kv1.3 in the spotlight for treating immune diseases. Expert Opin Ther Targets 2024; 28:67-82. [PMID: 38316438 DOI: 10.1080/14728222.2024.2315021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 02/02/2024] [Indexed: 02/07/2024]
Abstract
INTRODUCTION Kv1.3 is the main voltage-gated potassium channel of leukocytes from both the innate and adaptive immune systems. Channel function is required for common processes such as Ca2+ signaling but also for cell-specific events. In this context, alterations in Kv1.3 are associated with multiple immune disorders. Excessive channel activity correlates with numerous autoimmune diseases, while reduced currents result in increased cancer prevalence and immunodeficiencies. AREAS COVERED This review offers a general view of the role of Kv1.3 in every type of leukocyte. Moreover, diseases stemming from dysregulations of the channel are detailed, as well as current advances in their therapeutic research. EXPERT OPINION Kv1.3 arises as a potential immune target in a variety of diseases. Several lines of research focused on channel modulation have yielded positive results. However, among the great variety of specific channel blockers, only one has reached clinical trials. Future investigations should focus on developing simpler administration routes for channel inhibitors to facilitate their entrance into clinical trials. Prospective Kv1.3-based treatments will ensure powerful therapies while minimizing undesired side effects.
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Affiliation(s)
- María Navarro-Pérez
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Spain
| | - Jesusa Capera
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Spain
- The Kennedy Institute of Rheumatology, Nuffield Department of Orthopaedics Rheumatology & Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - Anna Benavente-Garcia
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Spain
| | - Silvia Cassinelli
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Spain
| | - Magalí Colomer-Molera
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Spain
| | - Antonio Felipe
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Spain
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Song Y, Ding L, An X, Zhao Y, Li X, Yang X, Xiao X. Hypokalemia after rituximab administration in nephrotic syndrome: two case reports. BMC Nephrol 2023; 24:214. [PMID: 37464309 DOI: 10.1186/s12882-023-03079-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 02/06/2023] [Indexed: 07/20/2023] Open
Abstract
Rituximab, a chimeric anti-CD20 monoclonal antibody, is an effective treatment for nephrotic syndrome. Hypokalemia is a rare adverse reaction among patients treated with rituximab although there have been extensive reports of acute and chronic adverse events with the administration of rituximab. We herein report two cases of symptomatic hypokalemia after intravenous rituximab administration in our center, to help health professionals consider the possibility of acute hypokalemia after rituximab administration, monitor potassium timely and develop an appropriate treatment plan.
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Affiliation(s)
- Yiyun Song
- Department of Nephrology, Qilu Hospital of Shandong University, No. 107 Wenhua West Road, 250000, Jinan, Shandong, PR China
| | - Lin Ding
- Department of Nephrology, Qilu Hospital of Shandong University, No. 107 Wenhua West Road, 250000, Jinan, Shandong, PR China
| | - Xin An
- Department of Nephrology, Qilu Hospital of Shandong University, No. 107 Wenhua West Road, 250000, Jinan, Shandong, PR China
| | - Yi Zhao
- Department of Nephrology, Qilu Hospital of Shandong University, No. 107 Wenhua West Road, 250000, Jinan, Shandong, PR China
| | - Xianhua Li
- Department of Nephrology, Qilu Hospital of Shandong University, No. 107 Wenhua West Road, 250000, Jinan, Shandong, PR China
| | - Xiangdong Yang
- Department of Nephrology, Qilu Hospital of Shandong University, No. 107 Wenhua West Road, 250000, Jinan, Shandong, PR China.
| | - Xiaoyan Xiao
- Department of Nephrology, Qilu Hospital of Shandong University, No. 107 Wenhua West Road, 250000, Jinan, Shandong, PR China.
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Novel Therapeutic Approaches of Ion Channels and Transporters in Cancer. Rev Physiol Biochem Pharmacol 2020; 183:45-101. [PMID: 32715321 DOI: 10.1007/112_2020_28] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The expression and function of many ion channels and transporters in cancer cells display major differences in comparison to those from healthy cells. These differences provide the cancer cells with advantages for tumor development. Accordingly, targeting ion channels and transporters have beneficial anticancer effects including inhibition of cancer cell proliferation, migration, invasion, metastasis, tumor vascularization, and chemotherapy resistance, as well as promoting apoptosis. Some of the molecular mechanisms associating ion channels and transporters with cancer include the participation of oxidative stress, immune response, metabolic pathways, drug synergism, as well as noncanonical functions of ion channels. This diversity of mechanisms offers an exciting possibility to suggest novel and more effective therapeutic approaches to fight cancer. Here, we review and discuss most of the current knowledge suggesting novel therapeutic approaches for cancer therapy targeting ion channels and transporters. The role and regulation of ion channels and transporters in cancer provide a plethora of exceptional opportunities in drug design, as well as novel and promising therapeutic approaches that may be used for the benefit of cancer patients.
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Lu XY, Liu BC, Cao YZ, Song C, Su H, Chen G, Klein JD, Zhang HX, Wang LH, Ma HP. High glucose reduces expression of podocin in cultured human podocytes by stimulating TRPC6. Am J Physiol Renal Physiol 2019; 317:F1605-F1611. [PMID: 31566428 DOI: 10.1152/ajprenal.00215.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The transient receptor potential canonical 6 (TRPC6) channel and podocin are colocalized in the glomerular slit diaphragm as an important complex to maintain podocyte function. Gain of TRPC6 function and loss of podocin function induce podocyte injury. We have previously shown that high glucose induces apoptosis of podocytes by activating TRPC6; however, whether the activated TRPC6 can alter podocin expression remains unknown. Western blot analysis and confocal microscopy were used to examine both expression levels of TRPC6, podocin, and nephrin and morphological changes of podocytes in response to high glucose. High glucose increased the expression of TRPC6 but reduced the expression of podocin and nephrin, in both cultured human podocytes and type 1 diabetic rat kidneys. The decreased podocin was diminished in TRPC6 knockdown podocytes. High glucose elevated intracellular Ca2+ in control podocytes but not in TRPC6 knockdown podocytes. High glucose also elevated the expression of a tight junction protein, zonula occludens-1, and induced the redistribution of zonula occludens-1 and loss of podocyte processes. These data together suggest that high glucose reduces protein levels of podocin by activating TRPC6 and induces morphological changes of cultured podocytes.
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Affiliation(s)
- Xiao-Yu Lu
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China.,Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Bing-Chen Liu
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia.,Department of Cardiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Yu-Ze Cao
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China.,Department of Neurology, Peking Union Medical College Hospital, Beijing, People's Republic of China
| | - Chang Song
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China.,Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Hua Su
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Guangping Chen
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
| | - Janet D Klein
- Department of Medicine, Renal Division, Emory University School of Medicine, Atlanta, Georgia
| | - Hui-Xue Zhang
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Li-Hua Wang
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, Georgia
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Inhibition of TRPC6 reduces non-small cell lung cancer cell proliferation and invasion. Oncotarget 2018; 8:5123-5134. [PMID: 28030826 PMCID: PMC5341750 DOI: 10.18632/oncotarget.14034] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 11/11/2016] [Indexed: 11/25/2022] Open
Abstract
Recent studies indicate that the transient receptor potential canonical 6 (TRPC6) channel is highly expressed in several types of cancer cells. However, it remains unclear whether TRPC6 contributes to the malignancy of human non-small cell lung cancer (NSCLC). We used a human NSCLC A549 cell line as a model and found that pharmacological blockade or molecular knockdown of TRPC6 channel inhibited A549 cell proliferation by arresting cell cycle at the S-G2M phase and caused a significant portion of cells detached and rounded-up, but did not induce any types of cell death. Western blot and cell cycle analysis show that the detached round cells at the S-G2M phase expressed more TRPC6 than the still attached polygon cells at the G1 phase. Patch-clamp data also show that TRPC whole-cell currents in the detached cells were significantly higher than in the still attached cells. Inhibition of Ca2+-permeable TRPC6 channels significantly reduced intracellular Ca2+ in A549 cells. Interestingly, either blockade or knockdown of TRPC6 strongly reduced the invasion of this NSCLC cell line and decreased the expression of an adherent protein, fibronectin, and a tight junction protein, zonula occluden protein-1 (ZO-1). These data suggest that TRPC6-mediated elevation of intracellular Ca2+ stimulates NSCLC cell proliferation by promoting cell cycle progression and that inhibition of TRPC6 attenuates cell proliferation and invasion. Therefore, further in vivo studies may lead to a consideration of using a specific TRPC6 blocker as a complement to treat NSCLC.
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Blockage of K(Ca)3.1 and Kv1.3 channels of the B lymphocyte decreases the inflammatory monocyte chemotaxis. Int Immunopharmacol 2016; 31:266-71. [PMID: 26795234 DOI: 10.1016/j.intimp.2015.12.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 12/14/2015] [Accepted: 12/21/2015] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To investigate the effects of Ca(2+) activated potassium channel KCa3.1 and voltage-gated potassium channel Kv1.3 of B lymphocyte on inflammatory monocytes chemotaxis and the potential mechanisms. MATERIALS AND METHODS Thanswell test was used to detect the inflammatory monocyte (Ly-6C(hi)) chemotaxis caused by the B lymphocyte. Enzyme-linked immunosorbent assay (ELISA) was applied to detecting the C-C motif ligand 7 (CCL7) in cultured media. Cell counting kit-8 (CCK) was used to detect the proliferation of B lymphocytes after activation and blockage of both KCa3.1 and Kv1.3 channels. Western blot was used to detect the expression of phosphorylated extracellular signal-regulated kinase (P-ERK) of the B lymphocytes. RESULTS When activated, B lymphocytes significantly proliferated. After application of KCa3.1 channel-specific inhibitor TRAM-34 and potent Kv1.3 channel inhibitor ShK, both B lymphocytes proliferation and Ly-6C(hi) monocyte chemotaxis were significantly inhibited. The expression of chemotaxis related factor CCL7 decreased remarkably. CONCLUSION The opening of KCa3.1 and Kv1.3 channels promote B lymphocyte activation, proliferation and Ly-6C(hi) monocyte chemotaxis. The increase of CCL7 secretion by B lymphocyte may explain the pro migration effects.
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Lu XY, Liu BC, Wang LH, Yang LL, Bao Q, Zhai YJ, Alli AA, Thai TL, Eaton DC, Wang WZ, Ma HP. Acute ethanol induces apoptosis by stimulating TRPC6 via elevation of superoxide in oxygenated podocytes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:965-74. [PMID: 25601712 DOI: 10.1016/j.bbamcr.2015.01.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 01/07/2015] [Accepted: 01/09/2015] [Indexed: 01/06/2023]
Abstract
Our recent studies indicate that hydrogen peroxide (H2O2) only at high concentrations can cause oxidative stress in renal epithelial cells and induce apoptosis of podocytes. Consistently, the present study shows that H2O2, even at 1 mM, failed to induce intracellular oxidative stress and apoptosis of the podocytes due to efficient activity of catalase, an enzyme which degrades H2O2 to produce water and oxygen (O2). However, H2O2 acted as a source of O2 to allow acute ethanol to induce superoxide production and cause apoptosis of the podocytes. In contrast, acute ethanol alone did not elevate intracellular superoxide, even though it stimulates expression and translocation of p47phox to the plasma membrane. Inhibition of catalase abolished not only O2 production from H2O2 degradation, but also NOX2-dependent superoxide production in the podocytes challenged by both H2O2 and acute ethanol. In parallel, acute ethanol in the presence of H2O2, but neither ethanol nor H2O2 alone, stimulated transient receptor potential canonical 6 (TRPC6) channels and caused TRPC6-dependent elevation of intracellular Ca2+. These data suggest that exogenous H2O2 does not induce oxidative stress due to rapid degradation to produce O2 in the podocytes, but the oxygenated podocytes become sensitive to acute ethanol challenge and undergo apoptosis via a TRPC6-dependent elevation of intracellular Ca2+. Since cultured podocytes are considered in hypoxic conditions, H2O2 may be used as a source of O2 to establish an ischemia-reperfusion model in some type of cultured cells in which H2O2 does not directly induce intracellular oxidative stress.
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Affiliation(s)
- Xiao-Yu Lu
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China; Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Bing-Chen Liu
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States; Department of Radiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China; Department of Cardiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Li-Hua Wang
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Li-Li Yang
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States; Department of Radiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China; Department of Cardiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Qing Bao
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Yu-Jia Zhai
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States; Department of Radiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China; Department of Cardiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Abdel A Alli
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Tiffany L Thai
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Douglas C Eaton
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States
| | - Wei-Zhi Wang
- Department of Neurology, the Second Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, GA 30322, United States.
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Lovastatin inhibits human B lymphoma cell proliferation by reducing intracellular ROS and TRPC6 expression. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:894-901. [PMID: 24518247 DOI: 10.1016/j.bbamcr.2014.02.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 01/17/2014] [Accepted: 02/02/2014] [Indexed: 12/21/2022]
Abstract
Clinical evidence suggests that statins reduce cancer incidence and mortality. However, there is lack of in vitro data to show the mechanism by which statins can reduce the malignancies of cancer cells. We used a human B lymphoma Daudi cells as a model and found that lovastatin inhibited, whereas exogenous cholesterol (Cho) stimulated, proliferation cell cycle progression in control Daudi cells, but not in the cells when transient receptor potential canonical 6 (TRPC6) channel was knocked down. Lovastatin decreased, whereas Cho increased, the levels of intracellular reactive oxygen species (ROS) respectively by decreasing or increasing the expression of p47-phox and gp91-phox (NOX2). Reducing intracellular ROS with either a mimetic superoxide dismutase (TEMPOL) or an NADPH oxidase inhibitor (apocynin) inhibited cell proliferation, particularly in Cho-treated cells. The effects of TEMPOL or apocynin were mimicked by inhibition of TRPC6 with SKF-96365. Lovastatin decreased TRPC6 expression and activity via a Cho-dependent mechanism, whereas Cho increased TRPC6 expression and activity via an ROS-dependent mechanism. Consistent with the fact that TRPC6 is a Ca(2+)-permeable channel, lovastatin decreased, but Cho increased, intracellular Ca(2+) also via ROS. These data suggest that lovastatin inhibits malignant B cell proliferation by reducing membrane Cho, intracellular ROS, TRPC6 expression and activity, and intracellular Ca(2+).
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Bortner CD, Cidlowski JA. Ion channels and apoptosis in cancer. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130104. [PMID: 24493752 DOI: 10.1098/rstb.2013.0104] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Humans maintain a constant cell number throughout their lifespan. This equilibrium of cell number is accomplished when cell proliferation and cell death are kept balanced, achieving a steady-state cell number. Abnormalities in cell growth or cell death can lead to an overabundance of cells known as neoplasm or tumours. While the perception of cancer is often that of an uncontrollable rate of cell growth or increased proliferation, a decrease in cell death can also lead to tumour formation. Most cells when detached from their normal tissue die. However, cancer cells evade cell death, tipping the balance to an overabundance of cell number. Therefore, overcoming this resistance to cell death is a decisive factor in the treatment of cancer. Ion channels play a critical role in cancer in regards to cell proliferation, malignant angiogenesis, migration and metastasis. Additionally, ion channels are also known to be critical components of apoptosis. In this review, we discuss the modes of cell death focusing on the ability of cancer cells to evade apoptosis. Specifically, we focus on the role ion channels play in controlling and regulating life/death decisions and how they can be used to overcome resistance to apoptosis in the treatment of cancer.
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Affiliation(s)
- Carl D Bortner
- The Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, Department of Health and Human Services, National Institutes of Health, , Research Triangle Park, NC 27709, USA
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Williams S, Bateman A, O'Kelly I. Altered expression of two-pore domain potassium (K2P) channels in cancer. PLoS One 2013; 8:e74589. [PMID: 24116006 PMCID: PMC3792113 DOI: 10.1371/journal.pone.0074589] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 08/03/2013] [Indexed: 01/31/2023] Open
Abstract
Potassium channels have become a focus in cancer biology as they play roles in cell behaviours associated with cancer progression, including proliferation, migration and apoptosis. Two-pore domain (K2P) potassium channels are background channels which enable the leak of potassium ions from cells. As these channels are open at rest they have a profound effect on cellular membrane potential and subsequently the electrical activity and behaviour of cells in which they are expressed. The K2P family of channels has 15 mammalian members and already 4 members of this family (K2P2.1, K2P3.1, K2P9.1, K2P5.1) have been implicated in cancer. Here we examine the expression of all 15 members of the K2P family of channels in a range of cancer types. This was achieved using the online cancer microarray database, Oncomine (www.oncomine.org). Each gene was examined across 20 cancer types, comparing mRNA expression in cancer to normal tissue. This analysis revealed all but 3 K2P family members (K2P4.1, K2P16.1, K2P18.1) show altered expression in cancer. Overexpression of K2P channels was observed in a range of cancers including breast, leukaemia and lung while more cancers (brain, colorectal, gastrointestinal, kidney, lung, melanoma, oesophageal) showed underexpression of one or more channels. K2P1.1, K2P3.1, K2P12.1, were overexpressed in a range of cancers. While K2P1.1, K2P3.1, K2P5.1, K2P6.1, K2P7.1 and K2P10.1 showed significant underexpression across the cancer types examined. This analysis supports the view that specific K2P channels may play a role in cancer biology. Their altered expression together with their ability to impact the function of other ion channels and their sensitivity to environmental stimuli (pO2, pH, glucose, stretch) makes understanding the role these channels play in cancer of key importance.
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Affiliation(s)
- Sarah Williams
- Human Development and Health, Centre for Human Development, Stem Cells and Regeneration, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Andrew Bateman
- Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Ita O'Kelly
- Human Development and Health, Centre for Human Development, Stem Cells and Regeneration, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- * E-mail: I.M.O'
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Liu BC, Song X, Lu XY, Li DT, Eaton DC, Shen BZ, Li XQ, Ma HP. High glucose induces podocyte apoptosis by stimulating TRPC6 via elevation of reactive oxygen species. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1434-42. [PMID: 23499875 DOI: 10.1016/j.bbamcr.2013.02.031] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 02/25/2013] [Accepted: 02/26/2013] [Indexed: 12/20/2022]
Abstract
Podocyte number is significantly reduced in diabetic patients and animal models, but the mechanism remains unclear. In the present study, we found that high glucose induced apoptosis in control podocytes which express transient receptor potential canonical 6 (TRPC6) channels, but not in TRPC6 knockdown podocytes in which TRPC6 was knocked down by TRPC6 silencing short hairpin RNA (shRNA). This effect was reproduced by treatment of podocytes with the reactive oxygen species (ROS), hydrogen peroxide (H2O2). Single-channel data from cell-attached, patch-clamp experiments showed that both high glucose and H2O2 activated the TRPC6 channel in control podocytes, but not in TRPC6 knockdown podocytes. Confocal microscopy showed that high glucose elevated ROS in podocytes and that H2O2 reduced the membrane potential of podocytes and elevated intracellular Ca(2+) via activation of TRPC6. Since intracellular Ca(2+) overload induces apoptosis, H2O2-induced apoptosis may result from TRPC6-mediated elevation of intracellular Ca(2+). These data together suggest that high glucose induces apoptosis in podocytes by stimulating TRPC6 via elevation of ROS.
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Affiliation(s)
- Bing-Chen Liu
- Department of Cardiology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
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