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Chen WB, Wang YX, Wang HG, An D, Sun D, Li P, Zhang T, Lu WG, Liu YQ. Role of TPEN in Amyloid-β 25-35-Induced Neuronal Damage Correlating with Recovery of Intracellular Zn 2+ and Intracellular Ca 2+ Overloading. Mol Neurobiol 2023:10.1007/s12035-023-03322-x. [PMID: 37059931 DOI: 10.1007/s12035-023-03322-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 03/17/2023] [Indexed: 04/16/2023]
Abstract
The overproduction of neurotoxic amyloid-β (Aβ) peptides in the brain is a hallmark of Alzheimer's disease (AD). To determine the role of intracellular zinc ion (iZn2+) dysregulation in mediating Aβ-related neurotoxicity, this study aimed to investigate whether N, N, N', N'‑tetrakis (2‑pyridylmethyl) ethylenediamine (TPEN), a Zn2+‑specific chelator, could attenuate Aβ25-35‑induced neurotoxicity and the underlying mechanism. We used the 3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay to measure the viability of primary hippocampal neurons. We also determined intracellular Zn2+ and Ca2+ concentrations, mitochondrial and lysosomal functions, and intracellular reactive oxygen species (ROS) content in hippocampal neurons using live-cell confocal imaging. We detected L-type voltage-gated calcium channel currents (L-ICa) in hippocampal neurons using the whole‑cell patch‑clamp technique. Furthermore, we measured the mRNA expression levels of proteins related to the iZn2+ buffer system (ZnT-3, MT-3) and voltage-gated calcium channels (Cav1.2, Cav1.3) in hippocampal neurons using RT-PCR. The results showed that TPEN attenuated Aβ25-35‑induced neuronal death, relieved the Aβ25-35‑induced increase in intracellular Zn2+ and Ca2+ concentrations; reversed the Aβ25-35‑induced increase in ROS content, the Aβ25-35‑induced increase in the L-ICa peak amplitude at different membrane potentials, the Aβ25-35‑induced the dysfunction of the mitochondria and lysosomes, and the Aβ25-35‑induced decrease in ZnT-3 and MT-3 mRNA expressions; and increased the Cav1.2 mRNA expression in the hippocampal neurons. These results suggest that TPEN, the Zn2+-specific chelator, attenuated Aβ25-35‑induced neuronal damage, correlating with the recovery of intracellular Zn2+ and modulation of abnormal Ca2+-related signaling pathways.
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Affiliation(s)
- Wen-Bo Chen
- College of Life Sciences, Nankai University, Tianjin, 300071, China
- School of Basic Medical Science, Henan University, Kaifeng, 475004, China
| | - Yu-Xiang Wang
- Department of Immunology and Pathogenic Biology, School of Basic Medical Sciences, Hebei University of Chinese Medicine, Shijiazhuang, 050200, Hebei, China
| | - Hong-Gang Wang
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Di An
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Dan Sun
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Pan Li
- Tianjin Key Laboratory of Cerebral Vascular and Neurodegenerative Diseases, Tianjin Neurosurgery Institute, Department of Neurology, Tianjin Huanhu Hospital Affiliated to Nankai University, Tianjin, China
| | - Tao Zhang
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Wan-Ge Lu
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Yan-Qiang Liu
- College of Life Sciences, Nankai University, Tianjin, 300071, China.
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2
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Tauskela JS, Brunette E, Aylsworth A, Zhao X. Neuroprotection against supra-lethal 'stroke in a dish' insults by an anti-excitotoxic receptor antagonist cocktail. Neurochem Int 2022; 158:105381. [PMID: 35764225 DOI: 10.1016/j.neuint.2022.105381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 06/07/2022] [Accepted: 06/19/2022] [Indexed: 10/17/2022]
Abstract
The goal of this study was to identify cocktails of drugs able to protect cultured rodent cortical neurons against increasing durations of oxygen-glucose deprivation (OGD). As expected, a cocktail composed of an NMDA and AMPA receptor antagonists and a voltage gated Ca2+ channel blocker (MK-801, CNQX and nifedipine, respectively) provided complete neuroprotection against mild OGD. Increasingly longer durations of OGD necessitated increasing the doses of MK-801 and CNQX, until these cocktails ultimately failed to provide neuroprotection against supra-lethal OGD, even at maximal drug concentrations. Surprisingly, supplementation of any of these cocktails with blockers of TRPM7 channels for increasing OGD durations was not neuroprotective, unless these blockers possessed the ability to inhibit NMDA receptors. Supplementation of the maximally effective cocktail with other NMDA receptor antagonists augmented neuroprotection, suggesting insufficient NMDAR blockade by MK-801. Substitution of MK-801 in cocktails with high concentrations of a glycine site NMDA receptor antagonist caused the greatest improvements in neuroprotection, with the more potent SM-31900 superior to L689,560. Substitution of CQNX in cocktails with AMPA receptor antagonists at high concentrations also improved neuroprotection, particularly with the combination of SYM 2206 and NBQX. The most neuroprotective cocktail was thus composed of SM-31900, SYM2206, NBQX, nifedipine and the antioxidant trolox. Thus, the cumulative properties of antagonist potency and concentration in a cocktail dictate neuroprotective efficacy. The central target of supra-lethal OGD is excitotoxicity, which must be blocked to the greatest extent possible to minimize ion influx.
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Affiliation(s)
- Joseph S Tauskela
- National Research Council of Canada, Human Health Therapeutics, Building M-54, 1200 Montreal Road, Ottawa, ON, Canada, K1A 0R6.
| | - Eric Brunette
- National Research Council of Canada, Human Health Therapeutics, Building M-54, 1200 Montreal Road, Ottawa, ON, Canada, K1A 0R6
| | - Amy Aylsworth
- National Research Council of Canada, Human Health Therapeutics, Building M-54, 1200 Montreal Road, Ottawa, ON, Canada, K1A 0R6
| | - Xigeng Zhao
- National Research Council of Canada, Human Health Therapeutics, Building M-54, 1200 Montreal Road, Ottawa, ON, Canada, K1A 0R6
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Sun X, Kang F, Shen Y, Shen Y, Li J. Dexmedetomidine and Phosphocreatine Post-treatment Provides Protection against Focal Cerebral Ischemia-reperfusion Injury in Rats. Acta Histochem Cytochem 2021; 54:105-113. [PMID: 34511649 PMCID: PMC8424249 DOI: 10.1267/ahc.21-00040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 05/13/2021] [Indexed: 01/29/2023] Open
Abstract
In this study we investigated the neuroprotective efficacy of dexmedetomidine (Dex) and phosphocreatine (PCr) alone or in combination in a rat model of focal cerebral ischemia-reperfusion injury (I/R). I/R was induced by intraluminal middle cerebral artery occlusion (MCAO) and reperfusion. Male Sprague-Dawley rats were randomly allocated to the Sham group and I/R group, and the I/R group was further divided into three subgroups: Dex (9 μg.kg−1 Dex), PCr (180 mg.kg−1 PCr) and Dex + PCr (9 μg.kg−1 Dex + 180 mg.kg−1 PCr). All treatments were given intravenously at the onset of reperfusion. After 24 hr of reperfusion, the neurological deficit score (NDS) was determined and a magnetic resonance imaging (MRI) scan was performed. Serum concentrations of malonaldehyde (MDA) and 4-hydroxynonenal (4-HNE) were measured and cerebral infarct volume was estimated by triphenyl tetrazolium chloride (TTC) staining. Blood brain barrier, neuronal and mitochondrial damage was assessed by optical and electron microscopy. Neuronal injury was further assessed using double cleaved caspase-3 and NeuN immunofluorescent staining. Compared with group I/R, Dex and PCr significantly reduced the neurological deficit score (P < 0.01), infarct volume (P < 0.01), and brain blood barrier, neuronal and mitochondrial damage. The level of oxidative stress (P < 0.001) and neuronal injury (P < 0.001) also decreased and surviving neurons increased (P < 0.001). Compared with Dex or PCr alone, the combination treatment had overall greater effects (P < 0.05). These results indicate that posttreatment with Dex or PCr decreases focal cerebral I/R injury and that these agents in combination have greater protective effects than each alone.
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Affiliation(s)
- Xiaofen Sun
- Department of Anesthesiology, First Affiliated Hospital of the University of Science and Technology of China
| | - Fang Kang
- Department of Anesthesiology, First Affiliated Hospital of the University of Science and Technology of China
| | - Yuxian Shen
- School of Basic Medical Sciences, Anhui Medical University
| | - Yujun Shen
- School of Basic Medical Sciences, Anhui Medical University
| | - Juan Li
- Department of Anesthesiology, First Affiliated Hospital of the University of Science and Technology of China
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4
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Chen WB, Wang YX, Wang HG, An D, Sun D, Li P, Zhang T, Lu WG, Liu YQ. TPEN attenuates amyloid-β 25-35-induced neuronal damage with changes in the electrophysiological properties of voltage-gated sodium and potassium channels. Mol Brain 2021; 14:124. [PMID: 34384467 PMCID: PMC8359616 DOI: 10.1186/s13041-021-00837-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 08/02/2021] [Indexed: 11/10/2022] Open
Abstract
To understand the role of intracellular zinc ion (Zn2+) dysregulation in mediating age-related neurodegenerative changes, particularly neurotoxicity resulting from the generation of excessive neurotoxic amyloid-β (Aβ) peptides, this study aimed to investigate whether N, N, N', N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN), a Zn2+-specific chelator, could attenuate Aβ25-35-induced neurotoxicity and the underlying electrophysiological mechanism. We used the 3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay to measure the viability of hippocampal neurons and performed single-cell confocal imaging to detect the concentration of Zn2+ in these neurons. Furthermore, we used the whole-cell patch-clamp technique to detect the evoked repetitive action potential (APs), the voltage-gated sodium and potassium (K+) channels of primary hippocampal neurons. The analysis showed that TPEN attenuated Aβ25-35-induced neuronal death, reversed the Aβ25-35-induced increase in intracellular Zn2+ concentration and the frequency of APs, inhibited the increase in the maximum current density of voltage-activated sodium channel currents induced by Aβ25-35, relieved the Aβ25-35-induced decrease in the peak amplitude of transient outward K+ currents (IA) and outward-delayed rectifier K+ currents (IDR) at different membrane potentials, and suppressed the steady-state activation and inactivation curves of IA shifted toward the hyperpolarization direction caused by Aβ25-35. These results suggest that Aβ25-35-induced neuronal damage correlated with Zn2+ dysregulation mediated the electrophysiological changes in the voltage-gated sodium and K+ channels. Moreover, Zn2+-specific chelator-TPEN attenuated Aβ25-35-induced neuronal damage by recovering the intracellular Zn2+ concentration.
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Affiliation(s)
- Wen-Bo Chen
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Yu-Xiang Wang
- Department of Immunology and Pathogenic Biology, School of Basic Medical Sciences, Hebei University of Chinese Medicine, Shijiazhuang, 050200, Hebei, People's Republic of China
| | - Hong-Gang Wang
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Di An
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Dan Sun
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Pan Li
- Tianjin Key Laboratory of Cerebral Vascular and Neurodegenerative Diseases, Tianjin Neurosurgery Institute, Department of Neurology, Tianjin Huanhu Hospital Affiliated to Nankai University, Tianjin, People's Republic of China
| | - Tao Zhang
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Wan-Ge Lu
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Yan-Qiang Liu
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China.
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Malko P, Jiang LH. TRPM2 channel-mediated cell death: An important mechanism linking oxidative stress-inducing pathological factors to associated pathological conditions. Redox Biol 2020; 37:101755. [PMID: 33130440 PMCID: PMC7600390 DOI: 10.1016/j.redox.2020.101755] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/17/2020] [Accepted: 10/08/2020] [Indexed: 12/26/2022] Open
Abstract
Oxidative stress resulting from the accumulation of high levels of reactive oxygen species is a salient feature of, and a well-recognised pathological factor for, diverse pathologies. One common mechanism for oxidative stress damage is via the disruption of intracellular ion homeostasis to induce cell death. TRPM2 is a non-selective Ca2+-permeable cation channel with a wide distribution throughout the body and is highly sensitive to activation by oxidative stress. Recent studies have collected abundant evidence to show its important role in mediating cell death induced by miscellaneous oxidative stress-inducing pathological factors, both endogenous and exogenous, including ischemia/reperfusion and the neurotoxicants amyloid-β peptides and MPTP/MPP+ that cause neuronal demise in the brain, myocardial ischemia/reperfusion, proinflammatory mediators that disrupt endothelial function, diabetogenic agent streptozotocin and diabetes risk factor free fatty acids that induce loss of pancreatic β-cells, bile acids that damage pancreatic acinar cells, renal ischemia/reperfusion and albuminuria that are detrimental to kidney cells, acetaminophen that triggers hepatocyte death, and nanoparticles that injure pericytes. Studies have also shed light on the signalling mechanisms by which these pathological factors activate the TRPM2 channel to alter intracellular ion homeostasis leading to aberrant initiation of various cell death pathways. TRPM2-mediated cell death thus emerges as an important mechanism in the pathogenesis of conditions including ischemic stroke, neurodegenerative diseases, cardiovascular diseases, diabetes, pancreatitis, chronic kidney disease, liver damage and neurovascular injury. These findings raise the exciting perspective of targeting the TRPM2 channel as a novel therapeutic strategy to treat such oxidative stress-associated diseases.
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Affiliation(s)
- Philippa Malko
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, UK
| | - Lin-Hua Jiang
- Sino-UK Joint Laboratory of Brain Function and Injury of Henan Province and Department of Physiology and Pathophysiology, Xinxiang Medical University, PR China; School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, UK.
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6
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Mai C, Mankoo H, Wei L, An X, Li C, Li D, Jiang LH. TRPM2 channel: A novel target for alleviating ischaemia-reperfusion, chronic cerebral hypo-perfusion and neonatal hypoxic-ischaemic brain damage. J Cell Mol Med 2019; 24:4-12. [PMID: 31568632 PMCID: PMC6933339 DOI: 10.1111/jcmm.14679] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 08/10/2019] [Accepted: 08/26/2019] [Indexed: 12/14/2022] Open
Abstract
The transient receptor potential melastatin-related 2 (TRPM2) channel, a reactive oxygen species (ROS)-sensitive cation channel, has been well recognized for being an important and common mechanism that confers the susceptibility to ROS-induced cell death. An elevated level of ROS is a salient feature of ischaemia-reperfusion, chronic cerebral hypo-perfusion and neonatal hypoxia-ischaemia. The TRPM2 channel is expressed in hippocampus, cortex and striatum, the brain regions that are critical for cognitive functions. In this review, we examine the recent studies that combine pharmacological and/or genetic interventions with using in vitro and in vivo models to demonstrate a crucial role of the TRPM2 channel in brain damage by ischaemia-reperfusion, chronic cerebral hypo-perfusion and neonatal hypoxic-ischaemia. We also discuss the current understanding of the underlying TRPM2-dependent cellular and molecular mechanisms. These new findings lead to the hypothesis of targeting the TRPM2 channel as a potential novel therapeutic strategy to alleviate brain damage and cognitive dysfunction caused by these conditions.
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Affiliation(s)
- Chendi Mai
- Sino-UK Joint Laboratory of Brian Function and Injury of Henan Province and Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, China.,Sanquan College of Xinxiang Medical University, Xinxiang, China
| | - Harneet Mankoo
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Linyu Wei
- Sino-UK Joint Laboratory of Brian Function and Injury of Henan Province and Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, China
| | - Xinfang An
- Sino-UK Joint Laboratory of Brian Function and Injury of Henan Province and Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, China.,Xinxiang Maternal and Child Health Care Hospital, Xinxiang, China
| | - Chaokun Li
- Sino-UK Joint Laboratory of Brian Function and Injury of Henan Province and Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, China
| | - Dongliang Li
- Sino-UK Joint Laboratory of Brian Function and Injury of Henan Province and Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, China.,Sanquan College of Xinxiang Medical University, Xinxiang, China
| | - Lin-Hua Jiang
- Sino-UK Joint Laboratory of Brian Function and Injury of Henan Province and Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, China.,Sanquan College of Xinxiang Medical University, Xinxiang, China.,School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
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7
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Eom JW, Kim TY, Seo BR, Park H, Koh JY, Kim YH. Identifying New AMP-Activated Protein Kinase Inhibitors That Protect against Ischemic Brain Injury. ACS Chem Neurosci 2019; 10:2345-2354. [PMID: 30763060 DOI: 10.1021/acschemneuro.8b00654] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
We recently reported that AMP-activated protein kinase (AMPK) contributes to zinc-induced neuronal death by inducing Bim, a pro-apoptotic Bcl-2 homology domain 3-only protein, in a liver kinase B1 (LKB1)-dependent manner. Current data suggest AMPK plays key roles in excitotoxicity and ischemic brain injury, with zinc neurotoxicity representing at least one mechanism of ischemic neuronal death. Inhibition of AMPK could be a viable therapeutic strategy to prevent ischemic brain injury following stroke. This prompted our search for novel inhibitors of AMPK activity and zinc-induced neuronal death using cultured mouse cortex and a rat model of brain injury after middle cerebral artery occlusion (MCAO). In structure-based virtual screening, 118 compounds were predicted to bind the active site of AMPK α2, and 40 showed in vitro AMPK α2 inhibitory activity comparable to compound C (a well-known, potent AMPK inhibitor). In mouse cortical neuronal cultures, 7 of 40 compound reduced zinc-induced neuronal death at levels comparable to compound C. Ultimately, only agents 2G11 and 1H10 significantly attenuated various types of neuronal death, including oxidative stress, excitotoxicity, and apoptosis. When administered as intracerebroventricular injections prior to permanent MCAO in rats, 2G11 and 1H10 reduced brain infarct volumes, whereas compound C did not. Therefore, these novel AMPK inhibitors could be drug development candidates to treat stroke.
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Affiliation(s)
- Jae-Won Eom
- Department of Molecular Biology, Sejong University, Seoul 05006, Republic of Korea
| | - Tae-Youn Kim
- Neural Injury Research Laboratory, University of Ulsan College of Medicine, Seoul 138-736, Republic of Korea
| | - Bo-Ra Seo
- Neural Injury Research Laboratory, University of Ulsan College of Medicine, Seoul 138-736, Republic of Korea
| | - Hwangseo Park
- Department of Integrative Bioscience and Biotechnology, Sejong University, Seoul 05006, Republic of Korea
| | - Jae-Young Koh
- Neural Injury Research Laboratory, University of Ulsan College of Medicine, Seoul 138-736, Republic of Korea
- Department of Neurology, University of Ulsan College of Medicine, Seoul 138-736, Republic of Korea
| | - Yang-Hee Kim
- Department of Molecular Biology, Sejong University, Seoul 05006, Republic of Korea
- Department of Integrative Bioscience and Biotechnology, Sejong University, Seoul 05006, Republic of Korea
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8
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Slepchenko KG, Holub JM, Li YV. Intracellular zinc increase affects phosphorylation state and subcellular localization of protein kinase C delta (δ). Cell Signal 2018; 44:148-157. [DOI: 10.1016/j.cellsig.2018.01.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 01/14/2018] [Indexed: 10/18/2022]
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Takeda A, Tamano H. The Impact of Synaptic Zn 2+ Dynamics on Cognition and Its Decline. Int J Mol Sci 2017; 18:ijms18112411. [PMID: 29135924 PMCID: PMC5713379 DOI: 10.3390/ijms18112411] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/31/2017] [Accepted: 11/09/2017] [Indexed: 11/16/2022] Open
Abstract
The basal levels of extracellular Zn2+ are in the range of low nanomolar concentrations and less attention has been paid to Zn2+, compared to Ca2+, for synaptic activity. However, extracellular Zn2+ is necessary for synaptic activity. The basal levels of extracellular zinc are age-dependently increased in the rat hippocampus, implying that the basal levels of extracellular Zn2+ are also increased age-dependently and that extracellular Zn2+ dynamics are linked with age-related cognitive function and dysfunction. In the hippocampus, the influx of extracellular Zn2+ into postsynaptic neurons, which is often linked with Zn2+ release from neuron terminals, is critical for cognitive activity via long-term potentiation (LTP). In contrast, the excess influx of extracellular Zn2+ into postsynaptic neurons induces cognitive decline. Interestingly, the excess influx of extracellular Zn2+ more readily occurs in aged dentate granule cells and intracellular Zn2+-buffering, which is assessed with ZnAF-2DA, is weakened in the aged dentate granule cells. Characteristics (easiness) of extracellular Zn2+ influx seem to be linked with the weakened intracellular Zn2+-buffering in the aged dentate gyrus. This paper deals with the impact of synaptic Zn2+ signaling on cognition and its decline in comparison with synaptic Ca2+ signaling.
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Affiliation(s)
- Atsushi Takeda
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
| | - Hanuna Tamano
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
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10
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Tamano H, Nishio R, Takeda A. Involvement of intracellular Zn 2+ signaling in LTP at perforant pathway-CA1 pyramidal cell synapse. Hippocampus 2017; 27:777-783. [PMID: 28380662 DOI: 10.1002/hipo.22730] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 03/28/2017] [Accepted: 03/29/2017] [Indexed: 11/06/2022]
Abstract
Physiological significance of synaptic Zn2+ signaling was examined at perforant pathway-CA1 pyramidal cell synapses. In vivo long-term potentiation (LTP) at perforant pathway-CA1 pyramidal cell synapses was induced using a recording electrode attached to a microdialysis probe and the recording region was locally perfused with artificial cerebrospinal fluid (ACSF) via the microdialysis probe. Perforant pathway LTP was not attenuated under perfusion with CaEDTA (10 mM), an extracellular Zn2+ chelator, but attenuated under perfusion with ZnAF-2DA (50 μM), an intracellular Zn2+ chelator, suggesting that intracellular Zn2+ signaling is required for perforant pathway LTP. Even in rat brain slices bathed in CaEDTA in ACSF, intracellular Zn2+ level, which was measured with intracellular ZnAF-2, was increased in the stratum lacunosum-moleculare where perforant pathway-CA1 pyramidal cell synapses were contained after tetanic stimulation. These results suggest that intracellular Zn2+ signaling, which originates in internal stores/proteins, is involved in LTP at perforant pathway-CA1 pyramidal cell synapses. Because the influx of extracellular Zn2+ , which originates in presynaptic Zn2+ release, is involved in LTP at Schaffer collateral-CA1 pyramidal cell synapses, synapse-dependent Zn2+ dynamics may be involved in plasticity of postsynaptic CA1 pyramidal cells.
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Affiliation(s)
- Haruna Tamano
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan
| | - Ryusuke Nishio
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan
| | - Atsushi Takeda
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka, 422-8526, Japan
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11
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Gerber PA, Rutter GA. The Role of Oxidative Stress and Hypoxia in Pancreatic Beta-Cell Dysfunction in Diabetes Mellitus. Antioxid Redox Signal 2017; 26:501-518. [PMID: 27225690 PMCID: PMC5372767 DOI: 10.1089/ars.2016.6755] [Citation(s) in RCA: 385] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 05/25/2016] [Indexed: 12/16/2022]
Abstract
SIGNIFICANCE Metabolic syndrome is a frequent precursor of type 2 diabetes mellitus (T2D), a disease that currently affects ∼8% of the adult population worldwide. Pancreatic beta-cell dysfunction and loss are central to the disease process, although understanding of the underlying molecular mechanisms is still fragmentary. Recent Advances: Oversupply of nutrients, including glucose and fatty acids, and the subsequent overstimulation of beta cells, are believed to be an important contributor to insulin secretory failure in T2D. Hypoxia has also recently been implicated in beta-cell damage. Accumulating evidence points to a role for oxidative stress in both processes. Although the production of reactive oxygen species (ROS) results from enhanced mitochondrial respiration during stimulation with glucose and other fuels, the expression of antioxidant defense genes is unusually low (or disallowed) in beta cells. CRITICAL ISSUES Not all subjects with metabolic syndrome and hyperglycemia go on to develop full-blown diabetes, implying an important role in disease risk for gene-environment interactions. Possession of common risk alleles at the SLC30A8 locus, encoding the beta-cell granule zinc transporter ZnT8, may affect cytosolic Zn2+ concentrations and thus susceptibility to hypoxia and oxidative stress. FUTURE DIRECTIONS Loss of normal beta-cell function, rather than total mass, is increasingly considered to be the major driver for impaired insulin secretion in diabetes. Better understanding of the role of oxidative changes, its modulation by genes involved in disease risk, and effects on beta-cell identity may facilitate the development of new therapeutic strategies to this disease. Antioxid. Redox Signal. 26, 501-518.
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Affiliation(s)
- Philipp A. Gerber
- Department of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Zurich, Zurich, Switzerland
| | - Guy A. Rutter
- Section of Cell Biology and Functional Genomics, Department of Medicine, Imperial College London, London, United Kingdom
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12
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Maintained LTP and Memory Are Lost by Zn 2+ Influx into Dentate Granule Cells, but Not Ca 2+ Influx. Mol Neurobiol 2017; 55:1498-1508. [PMID: 28176276 DOI: 10.1007/s12035-017-0428-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 01/26/2017] [Indexed: 12/21/2022]
Abstract
The idea that maintained LTP and memory are lost by either increase in intracellular Zn2+ in dentate granule cells or increase in intracellular Ca2+ was examined to clarify significance of the increases induced by excess synapse excitation. Both maintained LTP and space memory were impaired by injection of high K+ into the dentate gyrus, but rescued by co-injection of CaEDTA, which blocked high K+-induced increase in intracellular Zn2+ but not high K+-induced increase in intracellular Ca2+. High K+-induced disturbances of LTP and intracellular Zn2+ are rescued by co-injection of 6-cyano-7-nitroquinoxakine-2,3-dione, an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor antagonist, but not by co-injection of blockers of NMDA receptors, metabotropic glutamate receptors, and voltage-dependent calcium channels. Furthermore, AMPA impaired maintained LTP and the impairment was also rescued by co-injection of CaEDTA, which blocked increase in intracellular Zn2+, but not increase in intracellular Ca2+. NMDA and glucocorticoid, which induced Zn2+ release from the internal stores, did not impair maintained LTP. The present study indicates that increase in Zn2+ influx into dentate granule cells through AMPA receptors loses maintained LTP and memory. Regulation of Zn2+ influx into dentate granule cells is more critical for not only memory acquisition but also memory retention than that of Ca2+ influx.
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Takeda A, Tamano H. Innervation from the entorhinal cortex to the dentate gyrus and the vulnerability to Zn 2. J Trace Elem Med Biol 2016; 38:19-23. [PMID: 27267970 DOI: 10.1016/j.jtemb.2016.05.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 05/20/2016] [Accepted: 05/23/2016] [Indexed: 11/30/2022]
Abstract
Hippocampal Zn2+ homeostasis is critical for cognitive activity and hippocampus-dependent memory. Extracellular Zn2+ signaling is linked to extracellular glutamate signaling and leads to intracellular Zn2+ signaling, which is involved in cognitive activity. On the other hand, excess intracellular Zn2+ signaling that is induced by excess glutamate signaling is involved in cognitive decline. In the hippocampal formation, the dentate gyrus is the most vulnerable to aging and is thought to contribute to age-related cognitive decline. The layer II of the entorhinal cortex is the most vulnerable to neuronal death in Alzheimer's disease. The perforant pathway provides input from the layer II to the dentate gyrus and is one of the earliest affected pathways in Alzheimer's disease. Medial perforant pathway-dentate granule cell synapses are vulnerable to either excess intracellular Zn2+ or β-amyloid (Aβ)-bound zinc, which induce transient cognitive decline via attenuation of medial perforant pathway LTP. However, it is unknown whether the vulnerability to excess intracellular Zn2+ is involved in region-specific vulnerability to aging and Alzheimer's disease. To discover a strategy to prevent short-term cognitive decline in normal aging process and the pre-dementia stage of Alzheimer's disease, the present paper deals with vulnerability of medial perforant pathway-dentate granule cell synapses to intracellular Zn2+ dyshomeostasis and its possible involvement in differential vulnerability to aging and Alzheimer's disease in the hippocampal formation.
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Affiliation(s)
- Atsushi Takeda
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
| | - Hanuna Tamano
- Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
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14
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Takeda A, Tamano H. Insight into cognitive decline from Zn 2+ dynamics through extracellular signaling of glutamate and glucocorticoids. Arch Biochem Biophys 2016; 611:93-99. [DOI: 10.1016/j.abb.2016.06.021] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/23/2016] [Accepted: 06/30/2016] [Indexed: 02/06/2023]
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15
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Detrimental or beneficial: the role of TRPM2 in ischemia/reperfusion injury. Acta Pharmacol Sin 2016; 37:4-12. [PMID: 26725732 DOI: 10.1038/aps.2015.141] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 10/14/2015] [Indexed: 12/30/2022] Open
Abstract
Ischemia/reperfusion (I/R) injury is the main cause of tissue damage and dysfunction. I/R injury is characterized by Ca(2+) overload and production of reactive oxygen species (ROS), which play critical roles in the process of I/R injury to the brain, heart and kidney, but the underlying mechanisms are largely elusive. Recent evidence demonstrates that TRPM2, a Ca(2+)-permeable cationic channel and ROS sensor, is involved in I/R injury, but whether TRPM2 plays a protective or detrimental role in this process remains controversial. In this review, we discuss the recent progress in understanding the role of TRPM2 in reperfusion process after brain, heart and kidney ischemia and the potential of targeting TRPM2 for the development of therapeutic drugs to treat I/R injury.
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Stork CJ, Li YV. Elevated Cytoplasmic Free Zinc and Increased Reactive Oxygen Species Generation in the Context of Brain Injury. ACTA NEUROCHIRURGICA SUPPLEMENT 2016; 121:347-53. [DOI: 10.1007/978-3-319-18497-5_60] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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17
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Prakash A, Bharti K, Majeed ABA. Zinc: indications in brain disorders. Fundam Clin Pharmacol 2015; 29:131-49. [PMID: 25659970 DOI: 10.1111/fcp.12110] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 07/08/2014] [Accepted: 12/24/2014] [Indexed: 12/14/2022]
Abstract
Zinc is the authoritative metal which is present in our body, and reactive zinc metal is crucial for neuronal signaling and is largely distributed within presynaptic vesicles. Zinc also plays an important role in synaptic function. At cellular level, zinc is a modulator of synaptic activity and neuronal plasticity in both development and adulthood. Different importers and transporters are involved in zinc homeostasis. ZnT-3 is a main transporter involved in zinc homeostasis in the brain. It has been found that alterations in brain zinc status have been implicated in a wide range of neurological disorders including impaired brain development and many neurodegenerative disorders such as Alzheimer's disease, and mood disorders including depression, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and prion disease. Furthermore, zinc has also been implicated in neuronal damage associated with traumatic brain injury, stroke, and seizure. Understanding the mechanisms that control brain zinc homeostasis is thus critical to the development of preventive and treatment strategies for these and other neurological disorders.
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Affiliation(s)
- Atish Prakash
- Brain Degeneration and Therapeutics Group, Brain and Neuroscience Communities of Research, Universiti Teknologi MARA (UiTM), Shah Alam, 40450, Malaysia; Department of Pharmacology, ISF college of Pharmacy, Ghal kalan, Moga, 142-001, India; Brain Research Laboratory, Faculty of Pharmacy, Campus Puncak Alam, Universiti Teknologi MARA (UiTM), Bandar Puncak Alam, 42300, Malaysia
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Li C, Meng L, Li X, Li D, Jiang LH. Non-NMDAR neuronal Ca2+–permeable channels in delayed neuronal death and as potential therapeutic targets for ischemic brain damage. Expert Opin Ther Targets 2015; 19:879-92. [DOI: 10.1517/14728222.2015.1021781] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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TRPM2 channel deficiency prevents delayed cytosolic Zn2+ accumulation and CA1 pyramidal neuronal death after transient global ischemia. Cell Death Dis 2014; 5:e1541. [PMID: 25429618 PMCID: PMC4260752 DOI: 10.1038/cddis.2014.494] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 10/02/2014] [Accepted: 10/16/2014] [Indexed: 11/09/2022]
Abstract
Transient ischemia is a leading cause of cognitive dysfunction. Postischemic ROS generation and an increase in the cytosolic Zn2+ level ([Zn2+]c) are critical in delayed CA1 pyramidal neuronal death, but the underlying mechanisms are not fully understood. Here we investigated the role of ROS-sensitive TRPM2 (transient receptor potential melastatin-related 2) channel. Using in vivo and in vitro models of ischemia–reperfusion, we showed that genetic knockout of TRPM2 strongly prohibited the delayed increase in the [Zn2+]c, ROS generation, CA1 pyramidal neuronal death and postischemic memory impairment. Time-lapse imaging revealed that TRPM2 deficiency had no effect on the ischemia-induced increase in the [Zn2+]c but abolished the cytosolic Zn2+ accumulation during reperfusion as well as ROS-elicited increases in the [Zn2+]c. These results provide the first evidence to show a critical role for TRPM2 channel activation during reperfusion in the delayed increase in the [Zn2+]c and CA1 pyramidal neuronal death and identify TRPM2 as a key molecule signaling ROS generation to postischemic brain injury.
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New perspectives on oxidized genome damage and repair inhibition by pro-oxidant metals in neurological diseases. Biomolecules 2014; 4:678-703. [PMID: 25036887 PMCID: PMC4192668 DOI: 10.3390/biom4030678] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/24/2014] [Accepted: 06/25/2014] [Indexed: 12/23/2022] Open
Abstract
The primary cause(s) of neuronal death in most cases of neurodegenerative diseases, including Alzheimer's and Parkinson's disease, are still unknown. However, the association of certain etiological factors, e.g., oxidative stress, protein misfolding/aggregation, redox metal accumulation and various types of damage to the genome, to pathological changes in the affected brain region(s) have been consistently observed. While redox metal toxicity received major attention in the last decade, its potential as a therapeutic target is still at a cross-roads, mostly because of the lack of mechanistic understanding of metal dyshomeostasis in affected neurons. Furthermore, previous studies have established the role of metals in causing genome damage, both directly and via the generation of reactive oxygen species (ROS), but little was known about their impact on genome repair. Our recent studies demonstrated that excess levels of iron and copper observed in neurodegenerative disease-affected brain neurons could not only induce genome damage in neurons, but also affect their repair by oxidatively inhibiting NEIL DNA glycosylases, which initiate the repair of oxidized DNA bases. The inhibitory effect was reversed by a combination of metal chelators and reducing agents, which underscore the need for elucidating the molecular basis for the neuronal toxicity of metals in order to develop effective therapeutic approaches. In this review, we have focused on the oxidative genome damage repair pathway as a potential target for reducing pro-oxidant metal toxicity in neurological diseases.
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Yang W, Shen Y, Chen Y, Chen L, Wang L, Wang H, Xu S, Fang S, Fu Y, Yu Y, Shen Y. Mesencephalic astrocyte-derived neurotrophic factor prevents neuron loss via inhibiting ischemia-induced apoptosis. J Neurol Sci 2014; 344:129-38. [PMID: 25001514 DOI: 10.1016/j.jns.2014.06.042] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 06/15/2014] [Accepted: 06/19/2014] [Indexed: 01/17/2023]
Abstract
Mesencephalic astrocyte-derived neurotrophic factor (MANF) has been shown to be up-regulated under the focal cerebral ischemia and protected against ischemic injury in rats. However, the underlying mechanisms are unclear. The aim of this study was to verify the protection of MANF on the cerebral ischemic injury and further investigate the possible mechanisms. Rat focal ischemic model was established by middle cerebral artery occlusion (MCAO). The recombinant human MANF was therapeutically administrated to the ipsilateral ventricle at 2 h after MCAO. MANF decreased the number of the propidium iodide (PI)- and TUNEL-positive neural cells. Contrarily, MANF protected the NeuN-positive cells in hippocampus and cortex from death induced by ischemia. The more interesting results in this study were that MANF repressed the cleavage of caspase-3 triggered by focal cerebral ischemia. MANF also reduced the elevated levels of BIP/Grp78, phosphorylated IRE1, and splicing XBP1 induced by focal cerebral ischemia, but not affect CHOP expression. Meanwhile, focal cerebral ischemia elevated the levels of XBP1 mRNA, including unspliced XBP1 (XBP1u) and spliced XBP1 (XBP1s). However, MANF did not affect the expression of XBP1 mRNA, neither XBP1u nor XBP1s. These results suggest that MANF can prevent the neuron loss via inhibiting ischemia-induced apoptosis and regulating unfolded protein response-related genes.
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Affiliation(s)
- Wen Yang
- School of Pharmacy, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China; Biopharmaceutical Research Institute, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China.
| | - Yujun Shen
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China; Biopharmaceutical Research Institute, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China.
| | - Ying Chen
- School of Pharmacy, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China; Biopharmaceutical Research Institute, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China.
| | - Lu Chen
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China; Biopharmaceutical Research Institute, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China.
| | - Le Wang
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, Anhui, PR China.
| | - Haiping Wang
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China; Biopharmaceutical Research Institute, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China.
| | - Shengchun Xu
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China.
| | - Shengyun Fang
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China; Biopharmaceutical Research Institute, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China.
| | - Yu Fu
- Biopharmaceutical Research Institute, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China
| | - Yongqiang Yu
- Department of Radiology, The First Affiliated Hospital of Anhui Medical University, 218 Jixi Road, Hefei, Anhui, PR China.
| | - Yuxian Shen
- School of Basic Medical Sciences, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China; Biopharmaceutical Research Institute, Anhui Medical University, 81 Meishan Road, Hefei, Anhui, PR China.
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Angelé-Martínez C, Goodman C, Brumaghim J. Metal-mediated DNA damage and cell death: mechanisms, detection methods, and cellular consequences. Metallomics 2014; 6:1358-81. [DOI: 10.1039/c4mt00057a] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Metal ions cause various types of DNA damage by multiple mechanisms, and this damage is a primary cause of cell death and disease.
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Affiliation(s)
| | - Craig Goodman
- Department of Chemistry
- Clemson University
- Clemson, USA
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Cataldi M. The changing landscape of voltage-gated calcium channels in neurovascular disorders and in neurodegenerative diseases. Curr Neuropharmacol 2013; 11:276-97. [PMID: 24179464 PMCID: PMC3648780 DOI: 10.2174/1570159x11311030004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 02/02/2013] [Accepted: 02/14/2013] [Indexed: 12/12/2022] Open
Abstract
It is a common belief that voltage-gated calcium channels (VGCC) cannot carry toxic amounts of Ca2+ in neurons. Also, some of them as L-type channels are essential for Ca2+-dependent regulation of prosurvival gene-programs. However, a wealth of data show a beneficial effect of drugs acting on VGCCs in several neurodegenerative and neurovascular diseases. In the present review, we explore several mechanisms by which the “harmless” VGCCs may become “toxic” for neurons. These mechanisms could explain how, though usually required for neuronal survival, VGCCs may take part in neurodegeneration. We will present evidence showing that VGCCs can carry toxic Ca2+ when: a) their density or activity increases because of aging, chronic hypoxia or exposure to β-amyloid peptides or b) Ca2+-dependent action potentials carry high Ca2+ loads in pacemaker neurons. Besides, we will examine conditions in which VGCCs promote neuronal cell death without carrying excess Ca2+. This can happen, for instance, when they carry metal ions into the neuronal cytoplasm or when a pathological decrease in their activity weakens Ca2+-dependent prosurvival gene programs. Finally, we will explore the role of VGCCs in the control of nonneuronal cells that take part to neurodegeneration like those of the neurovascular unit or of microglia.
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Affiliation(s)
- Mauro Cataldi
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatological Sciences, Federico II University of Naples, Italy
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Braga MM, Rosemberg DB, de Oliveira DL, Loss CM, Córdova SD, Rico EP, Silva ES, Dias RD, Souza DO, Calcagnotto ME. Topographical analysis of reactive zinc in the central nervous system of adult zebrafish (Danio rerio). Zebrafish 2013; 10:376-88. [PMID: 23829199 DOI: 10.1089/zeb.2013.0882] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Reactive zinc (Zn) is crucial for neuronal signaling and is largely distributed within presynaptic vesicles of some axon terminals of distinct vertebrates. However, the distribution of reactive Zn throughout the central nervous system (CNS) is not fully explored. We performed a topographical study of CNS structures containing reactive Zn in the adult zebrafish (Danio rerio). Slices of CNS from zebrafish were stained by Neo-Timm and/or cresyl violet. The Zn specificity of Neo-Timm was evaluated with Zn chelants, N,N,N',N'-Tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), sodium diethyldithiocarbamate (DEDTC), Zn sulfide washing solution, and hydrochloric acid (HCl). Unfixed slices were also immersed in the fluorescent Zn probe (zinpyr-1). Yellow-to-brown-to-black granules were revealed by Neo-Timm in the zebrafish CNS. Telencephalon exhibited slightly stained regions, while rhombencephalic structures showed high levels of staining. Although stained granules were found on the cell bodies, rhombencephalic structures showed a neuropil staining profile. The TPEN produced a mild reduction in Neo-Timm staining, while HCl and mainly DEDTC abolished the staining, indicating a large Zn content. This result was also confirmed by the application of a Zn probe. The present topographical study revealed reactive Zn throughout the CNS in adult zebrafish that should be considered in future investigation of Zn in the brain on a larger scale.
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Affiliation(s)
- Marcos M Braga
- Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul , Porto Alegre, Brazil .
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Liao SL, Ou YC, Chang CY, Chen WY, Kuan YH, Wang WY, Pan HC, Chen CJ. Diethylmaleate and iodoacetate in combination caused profound cell death in astrocytes. J Neurochem 2013; 127:271-82. [PMID: 23647195 DOI: 10.1111/jnc.12291] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Accepted: 04/30/2013] [Indexed: 10/26/2022]
Abstract
Energy failure and oxidative stress have been implicated in the pathogenesis of ischemia. Here, we report a potential link between cytosolic phospholipase A₂ (cPLA₂) activation and energy failure/oxidative stress-induced astrocyte damage involving reactive oxygen species (ROS), protein kinase C-α (PKC-α), Src, Raf, and extracellular signal-regulated kinase (ERK) signaling and concurrent elevation of endogenous chelatable zinc. Energy failure and oxidative stress were produced by treating astrocytes with glycolytic inhibitor iodoacetate and glutathione chelator diethylmaleate, respectively. Diethylmaleate and iodoacetate in combination caused augmented damage to astrocytes in a time- and concentration-dependent manner. The cell death caused by diethylmaleate/iodoacetate was accompanied by increased ROS generation, PKC-α membrane translocation, Src, Raf, ERK, and cPLA₂ phosphorylation. Pharmacological studies revealed that these activations all contributed to diethylmaleate/iodoacetate-induced astrocyte death. Intriguingly, the mobilization of endogenous chelatable zinc was observed in diethylmaleate/iodoacetate-treated astrocytes. Zinc appears to act as a downstream mediator in response to diethylmaleate/iodoacetate treatment because of the attenuating effects of its chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine. These observations indicate that ROS/PKC-α, Src/Raf/ERK signaling and cPLA₂ are active participants in diethylmaleate/iodoacetate-induced astrocyte death and contribute to a vicious cycle between the depletion of ATP/glutathione and the mobilization of chelatable zinc as critical upstream effectors in initiating cytotoxic cascades.
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Affiliation(s)
- Su-Lan Liao
- Department of Education and Research, Taichung Veterans General Hospital, Taichung, Taiwan
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Yu X, Li YV. Neuroprotective effect of zinc chelator DEDTC in a zebrafish (Danio rerio) Model of Hypoxic Brain Injury. Zebrafish 2013; 10:30-5. [PMID: 23461417 DOI: 10.1089/zeb.2012.0777] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A study was conducted using zebrafish as a model of hypoxic brain injury to investigate the potential neuroprotective effects of zinc (Zn(2+)) chelation. The accumulation of intracellular Zn(2+) is a significant causal factor of the neuronal injury, and has been implicated in cell death followed by ischemic stroke. In this study, the zebrafish was placed in the hypoxia chamber with an extremely low level of dissolved oxygen (less than 0.8 mg/L), which is similar to the conditions in a complete global ischemic stroke. Approximately 50% of zebrafish died after a short period (≈11 min) of hypoxic treatment, suggesting that this is a responsive model system for use in evaluating treatments for hypoxic brain damage. The application of DEDTC reduced intracellular Zn(2+) accumulation and produced a concentration-dependent effect by increasing the survival rate of zebrafish. Zn(2+) chelation also enhanced zebrafish tolerance for hypoxia. When the brain damages were evaluated with TTC staining, the zebrafish that were treated with DEDTC in hypoxic treatment yielded the improvement of TTC staining that was similar to the healthy zebrafish brain. The results support that rising intracellular Zn(2+) plays a critical role in the neuronal damages, and demonstrate the protective effects of Zn(2+) chelation in hypoxic-ischemic brain injury in zebrafish.
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Affiliation(s)
- Xinge Yu
- Program in Biological Sciences, Ohio University, Athens, OH 45701, USA
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Mauleon G, Fall CP, Eddington DT. Precise spatial and temporal control of oxygen within in vitro brain slices via microfluidic gas channels. PLoS One 2012; 7:e43309. [PMID: 22905255 PMCID: PMC3419219 DOI: 10.1371/journal.pone.0043309] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 07/19/2012] [Indexed: 11/18/2022] Open
Abstract
The acute brain slice preparation is an excellent model for studying the details of how neurons and neuronal tissue respond to a variety of different physiological conditions. But open slice chambers ideal for electrophysiological and imaging access have not allowed the precise spatiotemporal control of oxygen in a way that might realistically model stroke conditions. To address this problem, we have developed a microfluidic add-on to a commercially available perfusion chamber that diffuses oxygen throughout a thin membrane and directly to the brain slice. A microchannel enables rapid and efficient control of oxygen and can be modified to allow different regions of the slice to experience different oxygen conditions. Using this novel device, we show that we can obtain a stable and homogeneous oxygen environment throughout the brain slice and rapidly alter the oxygen tension in a hippocampal slice. We also show that we can impose different oxygen tensions on different regions of the slice preparation and measure two independent responses, which is not easily obtainable with current techniques.
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Affiliation(s)
- Gerardo Mauleon
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Christopher P. Fall
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States of America
- Department of Computer Science, Georgetown University, Georgetown, Washington, D. C., United States of America
| | - David T. Eddington
- Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, United States of America
- * E-mail:
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Cope EC, Morris DR, Scrimgeour AG, Levenson CW. Use of zinc as a treatment for traumatic brain injury in the rat: effects on cognitive and behavioral outcomes. Neurorehabil Neural Repair 2012; 26:907-13. [PMID: 22331212 DOI: 10.1177/1545968311435337] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND While treatments for the behavioral deficits associated with traumatic brain injury (TBI) are currently limited, animal models suggest that zinc supplementation may increase resilience to TBI. OBJECTIVE This work tests the hypothesis that zinc supplementation after TBI can be used as treatment to improve behavioral outcomes such as anxiety, depression, and learning and memory. METHODS TBI was induced by controlled cortical impact to the medial frontal cortex. After TBI, rats were fed either a zinc adequate (ZA, 30 ppm) or zinc supplemented (ZS, 180 ppm) diet. Additional rats in each dietary group (ZA or ZS) were given a single intraperitoneal (ip) injection of zinc (30 mg/kg) 1 hour following injury. RESULTS Brain injury resulted in significant increases in anxiety-like and depression-like behaviors as well as impairments in learning and memory. None of the zinc treatments (dietary or ip zinc) improved TBI-induced anxiety. The 2-bottle saccharin preference test for anhedonia revealed that dietary ZS also did not improve depression-like behaviors. However, dietary ZS combined with an early ip zinc injection significantly reduced anhedonia (P < .001). Dietary supplementation after injury, but not zinc injection, significantly improved (P < .05) cognitive behavior as measured by the time spent finding the hidden platform in the Morris water maze test compared with injured rats fed a ZA diet. CONCLUSIONS These data suggest that zinc supplementation may be an effective treatment option for improving behavioral deficits such as cognitive impairment and depression following TBI.
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Sekler I, Silverman WF. Zinc homeostasis and signaling in glia. Glia 2012; 60:843-50. [DOI: 10.1002/glia.22286] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Accepted: 12/02/2011] [Indexed: 11/08/2022]
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Abstract
We earlier reported that Zn²+ chelation improved recovery of synaptic potentials after transient oxygen and glucose deprivation in brain slices. Such an effect could be because of reduced accumulation of Zn²+ in postsynaptic neurons, or could also be due to prevention of the onset of spreading depression-like events. A combination of optical and electrical recording was used here to show that Zn²+ chelation is effective because it delays spreading depression-like events. If the duration of oxygen/glucose deprivation was sufficient to generate a spreading depression-like event, irrecoverable Ca²+-dependent loss of synaptic potentials occurred, regardless of Zn²+ availability. These results identify a key mechanism underlying protective effects of Zn²+ chelation, and emphasize the importance of evaluating spreading depression-like events in studies of neuroprotection.
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Liao SL, Ou YC, Lin SY, Kao TK, Pan HC, Chang CY, Lai CY, Lu HC, Wang WY, Chen CJ. Signaling cascades mediate astrocyte death induced by zinc. Toxicol Lett 2011; 204:108-17. [DOI: 10.1016/j.toxlet.2011.04.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2011] [Revised: 04/11/2011] [Accepted: 04/19/2011] [Indexed: 10/18/2022]
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Martorano LM, Stork CJ, Li YV. UV irradiation-induced zinc dissociation from commercial zinc oxide sunscreen and its action in human epidermal keratinocytes. J Cosmet Dermatol 2010; 9:276-86. [DOI: 10.1111/j.1473-2165.2010.00521.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Chang CY, Ou YC, Kao TK, Pan HC, Lin SY, Liao SL, Wang WY, Lu HC, Chen CJ. Glucose exacerbates zinc-induced astrocyte death. Toxicol Lett 2010; 199:102-9. [DOI: 10.1016/j.toxlet.2010.08.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Revised: 08/16/2010] [Accepted: 08/20/2010] [Indexed: 01/04/2023]
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Lee SJ, Park MH, Kim HJ, Koh JY. Metallothionein-3 regulates lysosomal function in cultured astrocytes under both normal and oxidative conditions. Glia 2010; 58:1186-96. [PMID: 20544854 DOI: 10.1002/glia.20998] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cellular zinc plays a key role in lysosomal change and cell death in neurons and astrocytes under oxidative stress. Here, using astrocytes lacking metallothionein-3 (MT3), a potential source of labile zinc in the brain, we studied the role of MT3 in oxidative stress responses. H(2)O(2) induced a large increase in labile zinc in wild-type (WT) astrocytes, but stimulated only a modest rise in MT3-null astrocytes. In addition, H(2)O(2)-induced lysosomal membrane permeabilization (LMP) and cell death were comparably attenuated in MT3-null astrocytes. Expression and glycosylation of Lamp1 (lysosome-associated membrane protein 1) and Lamp2 were increased in MT3-null astrocytes, and the activities of several lysosomal enzymes were significantly reduced, indicating an effect of MT3 on lysosomal components. Consistent with lysosomal dysfunction in MT3-null cells, the level of LC3-II (microtubule-associated protein 1 light chain 3), a marker of early autophagy, was increased by oxidative stress in WT astrocytes, but not in MT3-null cells. Similar changes in Lamp1, LC3, and cathepsin-D were induced by the lysosomal inhibitors bafilomycin A1, chloroquine, and monensin, indicating that lysosomal dysfunction may lie upstream of changes observed in MT3-null astrocytes. Consistent with this idea, lysosomal accumulation of cholesterol and lipofuscin were augmented in MT3-null astrocytes. Similar to the results seen in MT3-null cells, MT3 knockdown by siRNA inhibited oxidative stress-induced increases in zinc and LMP. These results indicate that MT3 may play a key role in normal lysosomal function in cultured astrocytes.
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Affiliation(s)
- Sook-Jeong Lee
- Neural Injury Research Lab, University of Ulsan College of Medicine, Seoul, Korea
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Differential effects of zinc influx via AMPA/kainate receptor activation on subsequent induction of hippocampal CA1 LTP components. Brain Res 2010; 1354:188-95. [PMID: 20654593 DOI: 10.1016/j.brainres.2010.07.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 07/12/2010] [Accepted: 07/14/2010] [Indexed: 11/20/2022]
Abstract
Zinc potentiates the induction of NMDA receptor-dependent hippocampal CA1 long-term potentiation (LTP) at low micromolar concentrations, while excessive zinc attenuates it. Homeostasis of synaptic zinc is critical for LTP induction. In the present study, LTP at hippocampal CA1 synapses was analyzed focused on the timing and level of zinc influx into hippocampal cells in hippocampal slices from young rats. Zinc (100 microM) perfusion increased intracellular zinc level and subsequently attenuated CA1 LTP induced by tetanic stimuli at 100 Hz for 1s, which was completely inhibited in the presence of 50 microM APV, an NMDA receptor antagonist. When 10 microM CNQX, an AMPA/kainate receptor antagonist, which reduced zinc influx into hippocampal cells, was perfused prior to the zinc perfusion, the attenuation of CA1 LTP by the zinc perfusion was restored. These results suggest that facilitated zinc influx into hippocampal cells via AMPA/kainate receptor activation is an event to attenuate subsequent induction of NMDA receptor-dependent CA1 LTP. On the other hand, the zinc pre-perfusion also attenuated CA1 LTP induced by 200-Hz tetanus, but not NMDA receptor-independent CA1 LTP induced by 200-Hz tetanus in the presence of APV, suggesting that the induction of NMDA receptor-independent CA1 LTP is less susceptibility to the facilitated zinc influx into hippocampal CA1 cells. Zinc influx via AMPA/kainate receptor activation may differentially act on subsequent induction of CA1 LTP components.
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Stork CJ, Li YV. Zinc release from thapsigargin/IP3-sensitive stores in cultured cortical neurons. J Mol Signal 2010; 5:5. [PMID: 20504366 PMCID: PMC2897781 DOI: 10.1186/1750-2187-5-5] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Accepted: 05/26/2010] [Indexed: 11/30/2022] Open
Abstract
Background Changes in ionic concentration have a fundamental effect on numerous physiological processes. For example, IP3-gated thapsigargin sensitive intracellular calcium (Ca2+) storage provides a source of the ion for many cellular signaling events. Less is known about the dynamics of other intracellular ions. The present study investigated the intracellular source of zinc (Zn2+) that has been reported to play a role in cell signaling. Results In primary cultured cortical cells (neurons) labeled with intracellular fluorescent Zn2+ indicators, we showed that intracellular regions of Zn2+ staining co-localized with the endoplasmic reticulum (ER). The latter was identified with ER-tracker Red, a marker for ER. The colocalization was abolished upon exposure to the Zn2+ chelator TPEN, indicating that the local Zn2+ fluorescence represented free Zn2+ localized to the ER in the basal condition. Blockade of the ER Ca2+ pump by thapsigargin produced a steady increase of intracellular Zn2+. Furthermore, we determined that the thapsigargin-induced Zn2+ increase was not dependent on extracellular Ca2+ or extracellular Zn2+, suggesting that it was of intracellular origin. The applications of caged IP3 or IP3-3Kinase inhibitor (to increase available IP3) produced a significant increase in intracellular Zn2+. Conclusions Taken together, these results suggest that Zn2+ is sequestered into thapsigargin/IP3-sensitive stores and is released upon agonist stimulation.
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Affiliation(s)
- Christian J Stork
- Molecular and Cellular Biology Program, Ohio University, Athens, OH 45701, USA.
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