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Dragić M, Milićević K, Adžić M, Stevanović I, Ninković M, Grković I, Andjus P, Nedeljković N. Trimethyltin Increases Intracellular Ca 2+ Via L-Type Voltage-Gated Calcium Channels and Promotes Inflammatory Phenotype in Rat Astrocytes In Vitro. Mol Neurobiol 2021; 58:1792-1805. [PMID: 33394334 DOI: 10.1007/s12035-020-02273-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 12/21/2020] [Indexed: 12/29/2022]
Abstract
Astrocytes are the first responders to noxious stimuli by undergoing cellular and functional transition referred as reactive gliosis. Every acute or chronic disorder is accompanied by reactive gliosis, which could be categorized as detrimental (A1) of beneficial (A2) for nervous tissue. Another signature of pathological astrocyte activation is disturbed Ca2+ homeostasis, a common denominator of neurodegenerative diseases. Deregulation of Ca+ signaling further contributes to production of pro-inflammatory cytokines and reactive oxygen species. Trimethyltin (TMT) intoxication is a widely used model of hippocampal degeneration, sharing behavioral and molecular hallmarks of Alzheimer's disease (AD), thus representing a useful model of AD-like pathology. However, the role of astrocyte in the etiopathology of TMT-induced degeneration as well as in AD is not fully understood. In an effort to elucidate the role of astrocytes in such pathological processes, we examined in vitro effects of TMT on primary cortical astrocytes. The application of a range of TMT concentrations (5, 10, 50, and 100 μM) revealed changes in [Ca2+]i in a dose-dependent manner. Specifically, TMT-induced Ca2+ transients were due to L-type voltage-gated calcium channels (VGCC). Additionally, TMT induced mitochondrial depolarization independent of extracellular Ca2+ and disturbed antioxidative defense of astrocyte in several time points (4, 6, and 24 h) after 10 μM TMT intoxication, inducing oxidative and nitrosative stress. Chronic exposure (24 h) to 10 μM TMT induced strong upregulation of main pro-inflammatory factors, components of signaling pathways in astrocyte activation, A1 markers, and VGCC. Taken together, our results provide an insight into cellular and molecular events of astrocyte activation in chronic neuroinflammation.
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Affiliation(s)
- Milorad Dragić
- Department for General Physiology and Biophysics, Faculty of Biology, University of Belgrade, Studentski trg 16, Belgrade, Serbia.
| | - Katarina Milićević
- Center for Laser Microscopy, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Marija Adžić
- Department for General Physiology and Biophysics, Faculty of Biology, University of Belgrade, Studentski trg 16, Belgrade, Serbia
- Center for Laser Microscopy, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Ivana Stevanović
- Institute of Medical Research, Military Medical Academy, Belgrade, Serbia
- Medical Faculty of Military Medical Academy, University of Defense, Belgrade, Serbia
| | - Milica Ninković
- Institute of Medical Research, Military Medical Academy, Belgrade, Serbia
- Medical Faculty of Military Medical Academy, University of Defense, Belgrade, Serbia
| | - Ivana Grković
- Department of Molecular Biology and Endocrinology, Vinča Institute of Nuclear Sciences-National Institute of thе Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Pavle Andjus
- Center for Laser Microscopy, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Nadežda Nedeljković
- Department for General Physiology and Biophysics, Faculty of Biology, University of Belgrade, Studentski trg 16, Belgrade, Serbia
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Madadi S, Katebi M, Eftekharzadeh M, Mehdipour A, Pourheydar B, Mehdizadeh M. Partial Improvement of Spatial Memory Damages by Bone Marrow Mesenchymal Stem Cells Transplantation Following Trimethyltin Chloride Administration in the Rat CA1. Basic Clin Neurosci 2020; 10:567-577. [PMID: 32477474 PMCID: PMC7253807 DOI: 10.32598/bcn.9.10.90] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Revised: 05/20/2018] [Accepted: 01/08/2019] [Indexed: 01/01/2023] Open
Abstract
Introduction: Trimethyltin Chloride (TMT) is a neurotoxin that can kill neurons in the nervous system and activate astrocytes. This neurotoxin mainly damages the hippocampal neurons. After TMT injection, behavioral changes such as aggression and hyperactivity have been reported in animals along with impaired spatial and learning memory. Hence, TMT is a suitable tool for an experimental model of neurodegeneration. The present study aims to determine the palliative effects of Bone Marrow-derived Mesenchymal Stem Cells (BM-MSCs) on the hippocampi of rats damaged from TMT exposure. Methods: We assigned 28 male Wistar rats to the following groups: control, model, vehicle, and treatment. The groups received Intraperitoneal (IP) injections of 8 mg/kg TMT. After one week, stem cells were stereotactically injected into the CA1 of the right rats’ hippocampi. Spatial memory was determined by the Morris Water Maze (MWM) test 6 weeks after cell transplantation. Finally, the rats’ brains were perfused and stained by cresyl violet to determine the numbers of cells in the Cornus Ammonis (CA1) section of the hippocampus. We assessed the expressions of Glial Fibrillary Acidic Protein (GFAP) and Neuronal-specific Nuclear (NeuN) proteins in the right hippocampus by Western blot. Results: The MWM test showed that the treatment group had significantly higher traveled distances in the target quarter compared with the model and vehicle groups (P<0.05). Based on the result of cell count (Nissl staining), the number of cells increased in the treatment group compared with the model and vehicle groups (P<0.05). Western blot results showed up-regulation of GFAP and NeuN proteins in the model, vehicle, and treatment groups compared with the control group. Conclusion: Injection of BM-MSCs may lead to a behavioral and histological improvement in TMT-induced neurotoxicity by increasing the number of pyramidal neurons and improving memory.
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Affiliation(s)
- Soheila Madadi
- Department of Anatomy, Faculty of Medicine, Arak University of Medical Sciences, Arak, Iran
| | - Majid Katebi
- Department of Anatomy, Faculty of Medicine, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Mina Eftekharzadeh
- Department of Anatomy, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Ahmad Mehdipour
- Department of Tissue Engineering, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Bagher Pourheydar
- Neurophysiology Research Center, Department of Anatomy, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Mehdi Mehdizadeh
- Cellular and Molecular Research Center, Department of Anatomy, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
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Marei HE, Elnegiry AA, Zaghloul A, Althani A, Afifi N, Abd-Elmaksoud A, Farag A, Lashen S, Rezk S, Shouman Z, Cenciarelli C, Hasan A. Nanotubes impregnated human olfactory bulb neural stem cells promote neuronal differentiation in Trimethyltin-induced neurodegeneration rat model. J Cell Physiol 2017; 232:3586-3597. [PMID: 28121007 DOI: 10.1002/jcp.25826] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 01/03/2017] [Accepted: 01/24/2017] [Indexed: 12/12/2022]
Abstract
Neural stem cells (NSCs) are multipotent self-renewing cells that could be used in cellular-based therapy for a wide variety of neurodegenerative diseases including Alzheimer's diseases (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS). Being multipotent in nature, they are practically capable of giving rise to major cell types of the nervous tissue including neurons, astrocytes, and oligodendrocytes. This is in marked contrast to neural progenitor cells which are committed to a specific lineage fate. In previous studies, we have demonstrated the ability of NSCs isolated from human olfactory bulb (OB) to survive, proliferate, differentiate, and restore cognitive and motor deficits associated with AD, and PD rat models, respectively. The use of carbon nanotubes (CNTs) to enhance the survivability and differentiation potential of NSCs following their in vivo engraftment have been recently suggested. Here, in order to assess the ability of CNTs to enhance the therapeutic potential of human OBNSCs for restoring cognitive deficits and neurodegenerative lesions, we co-engrafted CNTs and human OBNSCs in TMT-neurodegeneration rat model. The present study revealed that engrafted human OBNSCS-CNTs restored cognitive deficits, and neurodegenerative changes associated with TMT-induced rat neurodegeneration model. Moreover, the CNTs seemed to provide a support for engrafted OBNSCs, with increasing their tendency to differentiate into neurons rather than into glia cells. The present study indicate the marked ability of CNTs to enhance the therapeutic potential of human OBNSCs which qualify this novel therapeutic paradigm as a promising candidate for cell-based therapy of different neurodegenerative diseases.
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Affiliation(s)
- Hany E Marei
- Biomedical Research Center, Qatar University, Doha, Qatar
| | - Ahmed A Elnegiry
- Department of Cytology and Histology, Faculty of Veterinary Medicine, Aswan University, Aswan, Egypt
| | - Adel Zaghloul
- Department of Surgery, Anesthesiology and Radiology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
| | - Asma Althani
- Biomedical Research Center, Qatar University, Doha, Qatar
| | | | - Ahmed Abd-Elmaksoud
- Department of Cytology and Histology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
| | - Amany Farag
- Department of Cytology and Histology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
| | - Samah Lashen
- Department of Cytology and Histology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
| | - Shymaa Rezk
- Department of Cytology and Histology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
| | - Zeinab Shouman
- Department of Cytology and Histology, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
| | | | - Anwarul Hasan
- Department of Mechanical and Industrial Engineering, Qatar University, Doha, Qatar
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Sakhaie MH, Soleimani M, Pirhajati V, Soleimani Asl S, Madjd Z, Mehdizadeh M. Coenzyme Q10 Ameliorates Trimethyltin Chloride Neurotoxicity in Experimental Model of Injury in Dentate Gyrus of Hippocampus: A Histopathological and Behavioral Study. IRANIAN RED CRESCENT MEDICAL JOURNAL 2016; 18:e30297. [PMID: 27781114 PMCID: PMC5065921 DOI: 10.5812/ircmj.30297] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 09/09/2015] [Accepted: 10/06/2015] [Indexed: 12/29/2022]
Abstract
Background Coenzyme Q10 has antioxidative and free radical scavenging effects. CoQ10 supplementation is known to have neuroprotective effects in some neurodegenerative diseases, such as Parkinson’s disease and Huntington’s disease. Objectives The aim of this study was to evaluate both histopathologic and behavioral whether Coenzyme Q10 is protective against trimethyltin chloride (TMT) induced hippocampal damage. Materials and Methods This was an experimental study. Thirty-six Balb/c mice were divided into four groups, as follows: 1) control group; 2) sham group of mice that received a 100 µL intraperitoneal injection (IP) of sesame oil; 3) TMT group of mice that received a single 2.5 mg/kg/day IP injection of TMT; and 4) TMT + CoQ10 group of mice that received a 10 mg/kg IP injection of CoQ10. Body weight and Morris water maze (MWM) responses were investigated. In addition, the dentate gyrus neurons of the hippocampus were evaluated histopathologically by light and electron microscopes. Results This study revealed that the body weight scale was found to be significantly higher in the CoQ10 group (21.39 ± 2.70), compared to the TMT group (19.39 ± 2.74) (P < 0.05). In the TMT group, the animals showed body a weight loss that was significantly lower than that of the control group (22.33 ± 3.06) (P < 0.05). Our results showed that CoQ10 provided protection against MWM deficits. Furthermore, TMT impaired the ability of mice to locate the hidden platform, compared to the control group (P < 0.05). Microscopic studies showed that TMT caused histopathological changes in the dentate gyrus and increased the number of necrotic neurons (476 ± 78.51), compared to the control group (208 ± 40.84) (P < 0.001). But, CoQ10 significantly attenuated (31 9 ± 60.08) the density of necrotic neurons compared to TMT (P < 0.05). Conclusions The results of the present study indicate that Coenzyme Q10 diminished neuronal necrosis and improved learning memory. Part of its beneficial effect is due to its potential to discount oxidative stress.
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Affiliation(s)
| | - Mansoureh Soleimani
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, IR Iran
| | - Vahid Pirhajati
- Department of Anatomical Sciences, Iran University of Medical Sciences, Tehran, IR Iran
| | - Sara Soleimani Asl
- Neurophysiology Research Center, Department of Anatomical Sciences, Hamadan University of Medical Sciences, Hamadan, IR Iran
| | - Zahra Madjd
- Oncopathology Research Center, Iran University of Medical Sciences, Tehran, IR Iran
| | - Mehdi Mehdizadeh
- Cellular and Molecular Research Center, Faculty of Advanced Technologies in Medicine, Department of Anatomical Sciences, Iran University of Medical Sciences, Tehran, IR Iran
- Corresponding Author: Mehdi Mehdizadeh, Cellular and Molecular Research Center, Faculty of Advanced Technologies in Medicine, Department of Anatomical Sciences, Iran University of Medical Sciences, Tehran, IR Iran. Tel: +98-2182944569, E-mail:
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Lee S, Yang M, Kim J, Kang S, Kim J, Kim JC, Jung C, Shin T, Kim SH, Moon C. Trimethyltin-induced hippocampal neurodegeneration: A mechanism-based review. Brain Res Bull 2016; 125:187-99. [PMID: 27450702 DOI: 10.1016/j.brainresbull.2016.07.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 07/19/2016] [Indexed: 12/22/2022]
Abstract
Trimethyltin (TMT), a toxic organotin compound, induces neurodegeneration selectively involving the limbic system and especially prominent in the hippocampus. Neurodegeneration-associated behavioral abnormalities, such as hyperactivity, aggression, cognitive deficits, and epileptic seizures, occur in both exposed humans and experimental animal models. Previously, TMT had been used generally in industry and agriculture, but the use of TMT has been limited because of its dangers to people. TMT has also been used to make a promising in vivo rodent model of neurodegeneration because of its region-specific characteristics. Several studies have demonstrated that TMT-treated animal models of epileptic seizures can be used as tools for researching hippocampus-specific neurotoxicity as well as the molecular mechanisms leading to hippocampal neurodegeneration. This review summarizes the in vivo and in vitro underlying mechanisms of TMT-induced hippocampal neurodegeneration (oxidative stress, inflammatory responses, and neuronal death/survival). Thus, the present review may be helpful to provide general insights into TMT-induced neurodegeneration and approaches to therapeutic interventions for neurodegenerative diseases, including temporal lobe epilepsy.
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Affiliation(s)
- Sueun Lee
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea
| | - Miyoung Yang
- Department of Anatomy, School of Medicine and Institute for Environmental Science, Wonkwang University, Jeonbuk 54538, South Korea
| | - Jinwook Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea
| | - Sohi Kang
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea
| | - Juhwan Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea
| | - Jong-Choon Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea
| | - Chaeyong Jung
- Department of Anatomy, Chonnam National University Medical School, Gwangju 61469, South Korea
| | - Taekyun Shin
- Department of Veterinary Anatomy, College of Veterinary Medicine, Jeju National University, Jeju 63243, South Korea
| | - Sung-Ho Kim
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea
| | - Changjong Moon
- Departments of Veterinary Anatomy and Veterinary Toxicology, College of Veterinary Medicine and BK21 Plus Project Team, Chonnam National University, Gwangju 61186, South Korea.
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Trela Z, Burdach Z, Siemieniuk A, Przestalski S, Karcz W. Effect of Trimethyltin Chloride on Slow Vacuolar (SV) Channels in Vacuoles from Red Beet (Beta vulgaris L.) Taproots. PLoS One 2015; 10:e0136346. [PMID: 26317868 PMCID: PMC4552677 DOI: 10.1371/journal.pone.0136346] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 08/01/2015] [Indexed: 12/21/2022] Open
Abstract
In the present study, patch-clamp techniques have been used to investigate the effect of trimethyltin chloride (Met3SnCl) on the slow vacuolar (SV) channels in vacuoles from red beet (Beta vulgaris L.) taproots. Activity of SV channels has been measured in whole-vacuole and cytosolic side-out patch configurations. It was found that addition of trimethyltin chloride to the bath solution suppressed, in a concentration-dependent manner, SV currents in red beet vacuoles. The time constant, τ, increased significantly in the presence of the organotin. When single channel activity was analyzed, only little channel activity could be recorded at 100 μM Met3SnCl. Trimethyltin chloride added to the bath medium significantly decreased (by ca. threefold at 100 μM Met3SnCl and at 100 mV voltage, as compared to the control medium) the open probability of single channels. Single channel recordings obtained in the presence and absence of trimethyltin chloride showed that the organotin only slightly (by <10%) decreased the unitary conductance of single channels. It was also found that Met3SnCl significantly diminished the number of SV channel openings, whereas it did not change the opening times of the channels. Taking into account the above and the fact that under the here applied experimental conditions (pH = 7.5) Met3SnCl is a non-dissociated (more lipophilic) compound, we suggest that the suppression of SV currents observed in the presence of the organotin results probably from its hydrophobic properties allowing this compound to translocate near the selectivity filter of the channel.
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Affiliation(s)
- Zenon Trela
- Department of Physics and Biophysics, Wrocław University of Environmental and Life Sciences, Norwida 25, PL-50-375, Wrocław, Poland
| | - Zbigniew Burdach
- Department of Plant Physiology, Faculty of Biology and Environmental Protection, University of Silesia, Jagiellońska 28, PL-40-032, Katowice, Poland
| | - Agnieszka Siemieniuk
- Department of Plant Physiology, Faculty of Biology and Environmental Protection, University of Silesia, Jagiellońska 28, PL-40-032, Katowice, Poland
| | - Stanisław Przestalski
- Department of Physics and Biophysics, Wrocław University of Environmental and Life Sciences, Norwida 25, PL-50-375, Wrocław, Poland
| | - Waldemar Karcz
- Department of Plant Physiology, Faculty of Biology and Environmental Protection, University of Silesia, Jagiellońska 28, PL-40-032, Katowice, Poland
- * E-mail:
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Ceccariglia S, D’altocolle A, Del Fa’ A, Silvestrini A, Barba M, Pizzolante F, Repele A, Michetti F, Gangitano C. Increased expression of Aquaporin 4 in the rat hippocampus and cortex during trimethyltin-induced neurodegeneration. Neuroscience 2014; 274:273-88. [DOI: 10.1016/j.neuroscience.2014.05.047] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 05/21/2014] [Accepted: 05/21/2014] [Indexed: 12/12/2022]
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Corvino V, Marchese E, Podda MV, Lattanzi W, Giannetti S, Di Maria V, Cocco S, Grassi C, Michetti F, Geloso MC. The neurogenic effects of exogenous neuropeptide Y: early molecular events and long-lasting effects in the hippocampus of trimethyltin-treated rats. PLoS One 2014; 9:e88294. [PMID: 24516629 PMCID: PMC3917853 DOI: 10.1371/journal.pone.0088294] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 01/05/2014] [Indexed: 01/08/2023] Open
Abstract
Modulation of endogenous neurogenesis is regarded as a promising challenge in neuroprotection. In the rat model of hippocampal neurodegeneration obtained by Trimethyltin (TMT) administration (8 mg/kg), characterised by selective pyramidal cell loss, enhanced neurogenesis, seizures and cognitive impairment, we previously demonstrated a proliferative role of exogenous neuropeptide Y (NPY), on dentate progenitors in the early phases of neurodegeneration. To investigate the functional integration of newly-born neurons, here we studied in adult rats the long-term effects of intracerebroventricular administration of NPY (2 µg/2 µl, 4 days after TMT-treatment), which plays an adjuvant role in neurodegeneration and epilepsy. Our results indicate that 30 days after NPY administration the number of new neurons was still higher in TMT+NPY-treated rats than in control+saline group. As a functional correlate of the integration of new neurons into the hippocampal network, long-term potentiation recorded in Dentate Gyrus (DG) in the absence of GABAA receptor blockade was higher in the TMT+NPY-treated group than in all other groups. Furthermore, qPCR analysis of Kruppel-like factor 9, a transcription factor essential for late-phase maturation of neurons in the DG, and of the cyclin-dependent kinase 5, critically involved in the maturation and dendrite extension of newly-born neurons, revealed a significant up-regulation of both genes in TMT+NPY-treated rats compared with all other groups. To explore the early molecular events activated by NPY administration, the Sonic Hedgehog (Shh) signalling pathway, which participates in the maintenance of the neurogenic hippocampal niche, was evaluated by qPCR 1, 3 and 5 days after NPY-treatment. An early significant up-regulation of Shh expression was detected in TMT+NPY-treated rats compared with all other groups, associated with a modulation of downstream genes. Our data indicate that the neurogenic effect of NPY administration during TMT-induced neurodegeneration involves early Shh pathway activation and results in a functional integration of newly-generated neurons into the local circuit.
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Affiliation(s)
- Valentina Corvino
- Institute of Anatomy and Cell Biology - Università Cattolica del Sacro Cuore, Rome, Italy
| | - Elisa Marchese
- Institute of Anatomy and Cell Biology - Università Cattolica del Sacro Cuore, Rome, Italy
| | - Maria Vittoria Podda
- Institute of Human Physiology - Università Cattolica del Sacro Cuore, Rome, Italy
| | - Wanda Lattanzi
- Institute of Anatomy and Cell Biology - Università Cattolica del Sacro Cuore, Rome, Italy
| | - Stefano Giannetti
- Institute of Anatomy and Cell Biology - Università Cattolica del Sacro Cuore, Rome, Italy
| | - Valentina Di Maria
- Institute of Anatomy and Cell Biology - Università Cattolica del Sacro Cuore, Rome, Italy
| | - Sara Cocco
- Institute of Human Physiology - Università Cattolica del Sacro Cuore, Rome, Italy
| | - Claudio Grassi
- Institute of Human Physiology - Università Cattolica del Sacro Cuore, Rome, Italy
| | - Fabrizio Michetti
- Institute of Anatomy and Cell Biology - Università Cattolica del Sacro Cuore, Rome, Italy
| | - Maria Concetta Geloso
- Institute of Anatomy and Cell Biology - Università Cattolica del Sacro Cuore, Rome, Italy
- * E-mail:
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Al-Taweel N, Varghese E, Florea AM, Büsselberg D. Cisplatin (CDDP) triggers cell death of MCF-7 cells following disruption of intracellular calcium ([Ca 2+] i) homeostasis. J Toxicol Sci 2014; 39:765-74. [DOI: 10.2131/jts.39.765] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
| | | | - Ana-Maria Florea
- Institute of Neuropathology, Heinrich-Heine University Düsseldorf
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Mitra S, Srivastava A, Khandelwal S. Tributyltin chloride induced testicular toxicity by JNK and p38 activation, redox imbalance and cell death in sertoli-germ cell co-culture. Toxicology 2013; 314:39-50. [PMID: 24055800 DOI: 10.1016/j.tox.2013.09.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 09/03/2013] [Accepted: 09/04/2013] [Indexed: 10/26/2022]
Abstract
The widespread use of tributyltin (TBT) as biocides in antifouling paints and agricultural chemicals has led to environmental and marine pollution. Human exposure occurs mainly through TBT contaminated seafood and drinking water. It is a well known endocrine disruptor in mammals, but its molecular mechanism in testicular damage is largely unexplored. This study was therefore, designed to ascertain effects of tributyltin chloride (TBTC) on sertoli-germ cell co-culture in ex-vivo and in the testicular tissue in-vivo conditions. An initial Ca(2+) rise followed by ROS generation and glutathione depletion resulted in oxidative damage and cell death. We observed p38 and JNK phosphorylation, stress proteins (Nrf2, MT and GST) induction and mitochondrial depolarization leading to caspase-3 activation. Prevention of TBTC reduced cell survival and cell death by Ca(2+) inhibitors and free radical scavengers specify definitive role of Ca(2+) and ROS. Sertoli cells were found to be more severely affected which in turn can hamper germ cells functionality. TBTC exposure in-vivo resulted in increased tin content in the testis with enhanced Evans blue leakage into the testicular tissue indicating blood-testis barrier disruption. Tesmin levels were significantly diminished and histopathological studies revealed marked tissue damage. Our data collectively indicates the toxic manifestations of TBTC on the male reproductive system and the mechanisms involved.
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Affiliation(s)
- Sumonto Mitra
- Immunotoxicology Division, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), P.O. Box 80, Mahatma Gandhi Marg, Lucknow 226001, India
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Gene expression profiling as a tool to investigate the molecular machinery activated during hippocampal neurodegeneration induced by trimethyltin (TMT) administration. Int J Mol Sci 2013; 14:16817-35. [PMID: 23955266 PMCID: PMC3759937 DOI: 10.3390/ijms140816817] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 08/06/2013] [Accepted: 08/08/2013] [Indexed: 12/31/2022] Open
Abstract
Trimethyltin (TMT) is an organotin compound exhibiting neurotoxicant effects selectively localized in the limbic system and especially marked in the hippocampus, in both experimental animal models and accidentally exposed humans. TMT administration causes selective neuronal death involving either the granular neurons of the dentate gyrus or the pyramidal cells of the Cornu Ammonis, with a different pattern of localization depending on the different species studied or the dosage schedule. TMT is broadly used to realize experimental models of hippocampal neurodegeneration associated with cognitive impairment and temporal lobe epilepsy, though the molecular mechanisms underlying the associated selective neuronal death are still not conclusively clarified. Experimental evidence indicates that TMT-induced neurodegeneration is a complex event involving different pathogenetic mechanisms, probably acting differently in animal and cell models, which include neuroinflammation, intracellular calcium overload, and oxidative stress. Microarray-based, genome-wide expression analysis has been used to investigate the molecular scenario occurring in the TMT-injured brain in different in vivo and in vitro models, producing an overwhelming amount of data. The aim of this review is to discuss and rationalize the state-of-the-art on TMT-associated genome wide expression profiles in order to identify comparable and reproducible data that may allow focusing on significantly involved pathways.
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Bironaite D, Westberg JA, Andersson LC, Venalis A. A variety of mild stresses upregulate stanniocalcin-1 (STC-1) and induce mitohormesis in neural crest-derived cells. J Neurol Sci 2013; 329:38-44. [PMID: 23566487 DOI: 10.1016/j.jns.2013.03.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 02/27/2013] [Accepted: 03/14/2013] [Indexed: 01/08/2023]
Abstract
We induced upregulation of stanniocalcin-1 (STC-1) by various mild and long lasting stresses and assayed its influence on mitochondrial membrane potential (MMP) in the neural crest-derived cell line Paju. The obtained data showed that starvation (24-96 h), exposure to 10nM TPA, and low concentrations (0.05-1 μM) of As2O3 significantly (3-5 times) upregulated Paju cell STC-1 RNA and stabilized the mitochondrial membrane potential (MMP). However, high concentrations of As2O3 (2.5-5.0 μM) increased intracellular ROS and free calcium levels and, consequently, suppressed STC-1 and MMP. The results show that cells preconditioned by various mild stresses expressed more STC-1 and their MMP were more resistant to a secondary exposure to As2O3 (2.5-5 μM, 96 h) demonstrating mitohormesis. We suggest that MMP deviation from control levels, to an extent innocuous to cell viability, is a general signal for STC-1-induction and MMP-protection. Our findings of Paju cell MMP-regulation may be of great importance for inventing new ways to prevent neurodegenerative diseases and unravel the mechanisms behind drug resistance.
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Affiliation(s)
- Daiva Bironaite
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania.
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Sadiq S, Ghazala Z, Chowdhury A, Büsselberg D. Metal toxicity at the synapse: presynaptic, postsynaptic, and long-term effects. J Toxicol 2012; 2012:132671. [PMID: 22287959 PMCID: PMC3263637 DOI: 10.1155/2012/132671] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 07/05/2011] [Indexed: 12/19/2022] Open
Abstract
Metal neurotoxicity is a global health concern. This paper summarizes the evidence for metal interactions with synaptic transmission and synaptic plasticity. Presynaptically metal ions modulate neurotransmitter release through their interaction with synaptic vesicles, ion channels, and the metabolism of neurotransmitters (NT). Many metals (e.g., Pb(2+), Cd(2+), and Hg(+)) also interact with intracellular signaling pathways. Postsynaptically, processes associated with the binding of NT to their receptors, activation of channels, and degradation of NT are altered by metals. Zn(2+), Pb(2+), Cu(2+), Cd(2+), Ni(2+), Co(2+), Li(3+), Hg(+), and methylmercury modulate NMDA, AMPA/kainate, and/or GABA receptors activity. Al(3+), Pb(2+), Cd(2+), and As(2)O(3) also impair synaptic plasticity by targeting molecules such as CaM, PKC, and NOS as well as the transcription machinery involved in the maintenance of synaptic plasticity. The multiple effects of metals might occur simultaneously and are based on the specific metal species, metal concentrations, and the types of neurons involved.
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Affiliation(s)
| | | | | | - Dietrich Büsselberg
- Weill Cornell Medical College in Qatar, Qatar Foundation—Education City, P.O. Box 24144, Doha, Qatar
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Geloso MC, Corvino V, Michetti F. Trimethyltin-induced hippocampal degeneration as a tool to investigate neurodegenerative processes. Neurochem Int 2011; 58:729-38. [DOI: 10.1016/j.neuint.2011.03.009] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Revised: 03/02/2011] [Accepted: 03/08/2011] [Indexed: 12/29/2022]
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15
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Lee JK, Lu S, Madhukar A. Real-Time dynamics of Ca2+, caspase-3/7, and morphological changes in retinal ganglion cell apoptosis under elevated pressure. PLoS One 2010; 5:e13437. [PMID: 20976135 PMCID: PMC2956638 DOI: 10.1371/journal.pone.0013437] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2010] [Accepted: 09/19/2010] [Indexed: 01/12/2023] Open
Abstract
Quantitative information on the dynamics of multiple molecular processes in individual live cells under controlled stress is central to the understanding of the cell behavior of interest and the establishment of reliable models. Here, the dynamics of the apoptosis regulator intracellular Ca(2+), apoptosis effector caspase-3/7, and morphological changes, as well as temporal correlation between them at the single cell level, are examined in retinal gangling cell line (differentiated RGC-5 cells) undergoing apoptosis at elevated hydrostatic pressure using a custom-designed imaging platform that allows long-term real-time simultaneous imaging of morphological and molecular-level physiological changes in large numbers of live cells (beyond the field-of-view of typical microscopy) under controlled hydrostatic pressure. This examination revealed intracellular Ca(2+) elevation with transient single or multiple peaks of less than 0.5 hour duration appearing at the early stages (typically less than 5 hours after the onset of 100 mmHg pressure) followed by gradual caspase-3/7 activation at late stages (typically later than 5 hours). The data reveal a strong temporal correlation between the Ca(2+) peak occurrence and morphological changes of neurite retraction and cell body shrinkage. This suggests that Ca(2+) elevation, through its impact on ion channel activity and water efflux, is likely responsible for the onset of apoptotic morphological changes. Moreover, the data show a significant cell-to-cell variation in the onset of caspase-3/7 activation, an inevitable consequence of the stochastic nature of the underlying biochemical reactions not captured by conventional assays based on population-averaged cellular responses. This real-time imaging study provides, for the first time, statistically significant data on simultaneous multiple molecular level changes to enable refinements and testing of models of the dynamics of mitochondria-mediated apoptosis. Further, the platform developed and the approach has direct significance to the study of a variety of signaling pathway phenomena.
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Affiliation(s)
- Jae Kyoo Lee
- Department of Biomedical Engineering, University of Southern California, Los Angles, California, United States of America
| | - Siyuan Lu
- Department of Physics, University of Southern California, Los Angles, California, United States of America
- Department of Ophthalmology, University of Southern California, Los Angles, California, United States of America
| | - Anupam Madhukar
- Department of Biomedical Engineering, University of Southern California, Los Angles, California, United States of America
- Department of Physics, University of Southern California, Los Angles, California, United States of America
- Department of Materials Science, University of Southern California, Los Angles, California, United States of America
- * E-mail:
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16
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Florea AM, Büsselberg D. Anti-cancer drugs interfere with intracellular calcium signaling. Neurotoxicology 2009; 30:803-10. [PMID: 19465052 DOI: 10.1016/j.neuro.2009.04.014] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 04/26/2009] [Accepted: 04/29/2009] [Indexed: 10/20/2022]
Abstract
(Neuro-)toxicity of metal and metal compounds is frequently highlighted. While specific metals or metal compounds are essential for cellular function, other metals are toxic and/or carcinogens. Metals can trigger accidental cell death in the form of necrosis, or activate programmed cell death in the form of apoptosis. The aim of anti-cancer therapy is induction of apoptosis in tumor cells. Therefore, there is an interesting twist in the toxicity of metals and metal compounds (e.g., arsenic trioxide, cisplatin); since they have a higher specificity to induce apoptosis in cancer cells (possibly due to the high turnover in these cells) they are used to cure some forms of cancer. A body of evidence suggests that second messengers, such as modulations in the intracellular calcium concentration, could be involved in metals induced toxicity as well as in the beneficial effects shown by anti-cancer drugs. Here we review the influence on calcium homeostasis induced by some metallic compounds: cisplatin, arsenic trioxide and trimethyltin chloride.
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Affiliation(s)
- Ana-Maria Florea
- Institut für Physiologie, Universitätsklinikum Essen, Universität Duisburg Essen, Hufelandstrasse 55, 45122 Essen, Germany
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17
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Florea AM, Büsselberg D. Arsenic trioxide in environmentally and clinically relevant concentrations interacts with calcium homeostasis and induces cell type specific cell death in tumor and non-tumor cells. Toxicol Lett 2008; 179:34-42. [PMID: 18485628 DOI: 10.1016/j.toxlet.2008.03.019] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Revised: 03/22/2008] [Accepted: 03/30/2008] [Indexed: 12/24/2022]
Abstract
While arsenic compounds are known as environmental toxicants (especially in drinking water) and as carcinogens, some arsenic compounds, like arsenic trioxide (As2O3), are clinically used in humans to treat some forms of cancer (e.g. leukemia). Although arsenic compounds have been studied intensively, their interactions with living cells are still not fully elucidated. We have previously proposed that modulation of intracellular calcium ([Ca2+]i) homeostasis induced by As2O3 could be an important mechanism to induce cytotoxicity. Here we demonstrate, using human cell models (neuroblastoma (SY-5Y) or embryonic kidney cells (HEK)) and confocal microscopy in combination with the calcium sensitive dye fluo 4-AM, that As2O3 interferes with calcium signaling at low (environmentally and clinically relevant concentrations of 100 pM to 1 microM). Within this concentration range, As2O3 had cell type specific cytotoxic effects, with neuroblastoma cells being more sensitive to As2O3 than HEK 293. In addition, by staining with Hoechst 33347 and counting micronucleated cells as well as apoptotic nuclei, As2O3 was found to increase the rate of apoptosis and DNA damage, which was also cell type specific. These results indicate that the As2O3-induced cell death could be triggered or mediated by [Ca2+]i signals and suggest that low concentrations of As2O3 are able to interfere with specific physiological processes in diverse cell models.
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Affiliation(s)
- Ana-Maria Florea
- Institut für Physiologie, Universitätsklinikum, Universität Duisburg Essen, Essen, Germany.
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18
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Piacentini R, Gangitano C, Ceccariglia S, Fà AD, Azzena GB, Michetti F, Grassi C. Dysregulation of intracellular calcium homeostasis is responsible for neuronal death in an experimental model of selective hippocampal degeneration induced by trimethyltin. J Neurochem 2008; 105:2109-21. [DOI: 10.1111/j.1471-4159.2008.05297.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Splettstoesser F, Florea AM, Büsselberg D. IP(3) receptor antagonist, 2-APB, attenuates cisplatin induced Ca2+-influx in HeLa-S3 cells and prevents activation of calpain and induction of apoptosis. Br J Pharmacol 2007; 151:1176-86. [PMID: 17592515 PMCID: PMC2189830 DOI: 10.1038/sj.bjp.0707335] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND AND PURPOSE Cisplatin drives specific types of tumour cells to apoptosis. In this study we investigate the involvement of intracellular calcium ([Ca(2+)](i)) in triggering apoptosis in two different cell lines. As cisplatin is used for the treatment of several forms of cancer we choose HeLa-S3 and U2-OS as two examples of tumour cell lines. EXPERIMENTAL APPROACH Cisplatin (1 nM-10 microM) was applied to HeLa-S3 and U2-OS cells and [Ca(2+)](i) measured with fluo-4, using laser scanning microscopy. Inositol-1,4,5-trisphosphate (IP(3)) receptors were visualized with immunostaining. Membrane conductances were measured with patch-clamp techniques. Levels of calpain and caspases were assessed by western blots and apoptotic cells were stained with Hoechst 33342 and counted. KEY RESULTS Cisplatin increases [Ca(2+)](i) concentration-dependently in HeLa-S3 but not in U2-OS cells. This elevation of [Ca(2+)](i) depended on extracellular Ca(2+) but was reduced by the IP(3) receptor blocker, 2-APB. This effect was not due to a Ca(2+) release triggered by Ca(2+) entry. Immunostaining showed IP(3)-receptors (type 1-3) at the cellular membrane of HeLa-S3 cells, but not in U2-OS cells. Electrophysiological experiments showed an increased membrane conductance with cisplatin only when Ca(2+) was present extracellularly. Increase of [Ca(2+)](i) was related to the activation of calpain but not caspase-8 and triggered apoptosis in HeLa-S3 but not in U2-OS cells. CONCLUSIONS AND IMPLICATIONS Our observations on the activation of IP(3)-receptors, calcium entry and apoptotic rate by cisplatin in specific carcinogenic cells might open new possibilities in the treatment of some forms of cancer.
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Affiliation(s)
- F Splettstoesser
- Institut für Physiologie, Universitätsklinikum, Universität Duisburg-Essen Essen, Germany
| | - A-M Florea
- Institut für Physiologie, Universitätsklinikum, Universität Duisburg-Essen Essen, Germany
| | - D Büsselberg
- Institut für Physiologie, Universitätsklinikum, Universität Duisburg-Essen Essen, Germany
- Author for correspondence:
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Lattanzi W, Bernardini C, Gangitano C, Michetti F. Hypoxia-like transcriptional activation in TMT-induced degeneration: microarray expression analysis on PC12 cells. J Neurochem 2007; 100:1688-702. [PMID: 17348866 DOI: 10.1111/j.1471-4159.2006.04331.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
To more clearly elucidate the complete network of molecular mechanisms induced by trimethyltin (TMT) toxicity, we used a homogeneous cell culture model represented by PC12 cells treated with 1 and 5 micromol/L TMT for 24 h. The gene expression profile was performed by microarray analysis, enabling us to identify 189 genes that were significantly modulated in treated cells, compared with controls. The main effects of TMT on gene expression seem to be related to the activation of metabolic processes (glycolysis and lipogenesis) along with cell death pathways, membrane remodeling and intracellular biomolecules trafficking. These alterations are triggered by the neurotoxicant earlier than a strong decrease in cell viability, which occurs at higher TMT concentrations or at later time points. Some aspects of the transcriptional modulation observed in this study resemble the gene activation known to occur during cell response to hypoxia. Other cell toxicants have also been reported to exert similar effects on gene expression. Therefore, our data help to delineate general basic adaptive mechanisms possibly shared by cells responding to different death-inducing noxae, such as TMT.
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Affiliation(s)
- Wanda Lattanzi
- Institute of Anatomy and Cell Biology, Catholic University, Rome, Italy
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21
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Florea AM, Splettstoesser F, Büsselberg D. Arsenic trioxide (As2O3) induced calcium signals and cytotoxicity in two human cell lines: SY-5Y neuroblastoma and 293 embryonic kidney (HEK). Toxicol Appl Pharmacol 2007; 220:292-301. [PMID: 17376498 DOI: 10.1016/j.taap.2007.01.022] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Revised: 01/08/2007] [Accepted: 01/29/2007] [Indexed: 10/23/2022]
Abstract
Arsenic trioxide (As(2)O(3)) has anticancer properties; however, its use also leads to neuro-, hepato- or nephro-toxicity, and therefore, it is important to understand the mechanism of As(2)O(3) toxicity. We studied As(2)O(3) influence on intracellular calcium ([Ca(2+)](i)) homeostasis of human neuroblastoma SY-5Y and embryonic kidney cells (HEK 293). We also relate the As(2)O(3) induced [Ca(2+)](i) modifications with cytotoxicity. We used Ca(2+) sensitive dyes (fluo-4 and rhod-2) combined with laser scanning microscopy or fluorescence activated cell sorting to measure Ca(2+) changes during the application of As(2)O(3) and we approach evaluation of cytotoxicity. As(2)O(3) (1 microM) increased [Ca(2+)](i) in SY-5Y and HEK 293 cells. Three forms of [Ca(2+)](i)-elevations were found: (1) steady-state increases, (2) transient [Ca(2+)](i)-elevations and (3) Ca(2+)-spikes. [Ca(2+)](i) modifications were independent from extracellular Ca(2+) but dependent on internal calcium stores. The effect was not reversible. Inositol triphosphate (IP(3)) and ryanodine (Ry) receptors are involved in regulation of signals induced by As(2)O(3). 2-APB and dantrolene significantly reduced the [Ca(2+)](i)-rise (p<0.001, t-test) but did not completely abolish [Ca(2+)](i)-elevation or spiking. This indicates that other Ca(2+) regulating mechanisms are involved. In cytotoxicity tests As(2)O(3) significantly reduced cell viability in both cell types. Staining with Hoechst 33342 showed occurrence of apoptosis and DNA damage. Our data suggest that [Ca(2+)](i) is an important messenger in As(2)O(3) induced cell death.
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Affiliation(s)
- Ana-Maria Florea
- Institut für Physiologie, Universitätsklinikum, Universität Duisburg Essen, Hufelandstrasse 55, 45122 Essen, Germany
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Krüger K, Höing T, Bensch W, Diepgrond V, Ahnefeld M, Madeja M, Binding N, Musshoff U. Effects of monomethyltin and dimethyltin compounds on heterologously expressed neuronal ion channels (Xenopus oocytes) and synaptic transmission (hippocampal slices). Neurotoxicology 2007; 28:114-25. [PMID: 16989903 DOI: 10.1016/j.neuro.2006.08.004] [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: 01/31/2006] [Revised: 07/28/2006] [Accepted: 08/14/2006] [Indexed: 11/25/2022]
Abstract
The aim of this study was to investigate the effects of monomethyltin trichloride (MMT) and dimethyltin dichloride (DMT) on various neuronal ion channels heterologously expressed in Xenopus oocytes and on synaptic transmission in hippocampal slices of young (14-21 days old) and adult (2-4 months old) rats. The Xenopus oocyte expression system was chosen to allow direct assessment of the effects of MMT and DMT both on glutamate receptors sensitive to AMPA and NMDA and on various voltage-operated potassium and sodium channels. Hippocampal slices were used to analyze the effects of MMT and DMT on synaptic potentials generated by the important excitatory Schaffer collateral-CA1 synapse. In general, MMT and DMT were found to have no effect either on voltage-operated sodium and potassium channels or on the metabotropic glutamate receptor but they did differentially affect the functions of ionotropic glutamate receptors and glutamatergic synaptic transmission. MMT (100 microM) significantly reduced NMDA-mediated ion currents by up to 32%, but had no effect on ion currents through AMPA receptors. In slices of adult rats, MMT had no effect on the amplitudes of evoked fEPSPs and brought about a 35% reduction in the LTP amplitudes. In contrast, in slices of young rats MMT evoked a reversible 30% increase in the amplitudes of fEPSPs but had no effect on LTP induction. DMT (100 microM) reduced ion currents through NMDA-receptor ion channels by up to 29% and those through AMPA-receptor ion channels by up to 7%. In hippocampal slices 100 microM DMT reduced the amplitudes of fEPSPs (adults: 50%; young rats: 70%) and LTP (adults: 40%; young rats: 55%). Neither of the organotins affected the paired-pulse facilitation at this synapse, indicating that the organotins exert their effects at the postsynaptic site. The action of MMT and DMT may contribute to the organotin-induced impairment of behavior patterns in connection with learning and memory.
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Affiliation(s)
- K Krüger
- Institute of Physiology I, University of Münster, Robert-Koch-Str. 27a, D-48149 Münster, Germany.
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Krüger K, Binding N, Straub H, Musshoff U. Effects of arsenite on long-term potentiation in hippocampal slices from young and adult rats. Toxicol Lett 2006; 165:167-73. [PMID: 16677784 DOI: 10.1016/j.toxlet.2006.03.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Revised: 03/16/2006] [Accepted: 03/20/2006] [Indexed: 10/24/2022]
Abstract
The effects of trivalent arsenite were tested at the Schaffer collateral-CA1 synapse of adult (2-4 month) and young (14-21 days) rats. Exposure of 100micromol/l arsenite led to a slight and reversible reduction of the amplitudes of evoked excitatory postsynaptic field potentials in adult and young rats, while exposure of 0.1 and 1micromol/l arsenite had no effects. The long-term potentiation (LTP) was significantly inhibited by arsenite in adult but not in young rats. Exposure of 0.1, 1 and 100micromol/l arsenite to slices of adult rats before and during the LTP stimulus led to a significant reduction in the potentiated amplitudes amounting to a maximum of 50% of the control values. In young animals, however, exposure of 1micromol/l arsenite showed no effect on the LTP potentiated amplitudes, while exposure of 100micromol/l arsenite led initially to a significant reduction in the amplitudes, compared to the control level, which was completely reversible 20min after washout. Exposure of 100micromol/l arsenite did not affect the paired-pulse facilitation, indicating that arsenite does not exert its effects by influencing presynaptic transmitter release mechanisms.
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Affiliation(s)
- Katharina Krüger
- Institut für Physiologie I, Universitätsklinikum Münster, Robert-Koch-Strasse 27a, D-48149 Münster, Germany.
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