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Campos J, Gleitze S, Hidalgo C, Núñez MT. IP 3R-Mediated Calcium Release Promotes Ferroptotic Death in SH-SY5Y Neuroblastoma Cells. Antioxidants (Basel) 2024; 13:196. [PMID: 38397794 PMCID: PMC10886377 DOI: 10.3390/antiox13020196] [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: 01/12/2024] [Accepted: 01/26/2024] [Indexed: 02/25/2024] Open
Abstract
Ferroptosis is an iron-dependent cell death pathway that involves the depletion of intracellular glutathione (GSH) levels and iron-mediated lipid peroxidation. Ferroptosis is experimentally caused by the inhibition of the cystine/glutamate antiporter xCT, which depletes cells of GSH, or by inhibition of glutathione peroxidase 4 (GPx4), a key regulator of lipid peroxidation. The events that occur between GPx4 inhibition and the execution of ferroptotic cell death are currently a matter of active research. Previous work has shown that calcium release from the endoplasmic reticulum (ER) mediated by ryanodine receptor (RyR) channels contributes to ferroptosis-induced cell death in primary hippocampal neurons. Here, we used SH-SY5Y neuroblastoma cells, which do not express RyR channels, to test if calcium release mediated by the inositol 1,4,5-trisphosphate receptor (IP3R) channel plays a role in this process. We show that treatment with RAS Selective Lethal Compound 3 (RSL3), a GPx4 inhibitor, enhanced reactive oxygen species (ROS) generation, increased cytoplasmic and mitochondrial calcium levels, increased lipid peroxidation, and caused cell death. The RSL3-induced calcium signals were inhibited by Xestospongin B, a specific inhibitor of the ER-resident IP3R calcium channel, by decreasing IP3R levels with carbachol and by IP3R1 knockdown, which also prevented the changes in cell morphology toward roundness induced by RSL3. Intracellular calcium chelation by incubation with BAPTA-AM inhibited RSL3-induced calcium signals, which were not affected by extracellular calcium depletion. We propose that GPx4 inhibition activates IP3R-mediated calcium release in SH-SY5Y cells, leading to increased cytoplasmic and mitochondrial calcium levels, which, in turn, stimulate ROS production and induce lipid peroxidation and cell death in a noxious positive feedback cycle.
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Affiliation(s)
- Joaquín Campos
- Chica and Heinz Schaller Foundation, Institute for Anatomy and Cell Biology, University of Heidelberg, 69120 Heidelberg, Germany;
| | - Silvia Gleitze
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago 8380000, Chile; (S.G.); (C.H.)
| | - Cecilia Hidalgo
- Biomedical Neuroscience Institute, Faculty of Medicine, Universidad de Chile, Santiago 8380000, Chile; (S.G.); (C.H.)
- Department of Neuroscience, Faculty of Medicine, Universidad de Chile, Santiago 8380000, Chile
- Physiology and Biophysics Program, Institute of Biomedical Sciences and Center for Exercise, Metabolism and Cancer Studies, Faculty of Medicine, Universidad de Chile, Santiago 8380000, Chile
| | - Marco T. Núñez
- Department of Biology, Faculty of Sciences, Universidad de Chile, Santiago 7800024, Chile
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Kumar A, Karuppagounder SS, Chen Y, Corona C, Kawaguchi R, Cheng Y, Balkaya M, Sagdullaev BT, Wen Z, Stuart C, Cho S, Ming GL, Tuvikene J, Timmusk T, Geschwind DH, Ratan RR. 2-Deoxyglucose drives plasticity via an adaptive ER stress-ATF4 pathway and elicits stroke recovery and Alzheimer's resilience. Neuron 2023; 111:2831-2846.e10. [PMID: 37453419 PMCID: PMC10528360 DOI: 10.1016/j.neuron.2023.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 05/10/2023] [Accepted: 06/20/2023] [Indexed: 07/18/2023]
Abstract
Intermittent fasting (IF) is a diet with salutary effects on cognitive aging, Alzheimer's disease (AD), and stroke. IF restricts a number of nutrient components, including glucose. 2-deoxyglucose (2-DG), a glucose analog, can be used to mimic glucose restriction. 2-DG induced transcription of the pro-plasticity factor, Bdnf, in the brain without ketosis. Accordingly, 2-DG enhanced memory in an AD model (5xFAD) and functional recovery in an ischemic stroke model. 2-DG increased Bdnf transcription via reduced N-linked glycosylation, consequent ER stress, and activity of ATF4 at an enhancer of the Bdnf gene, as well as other regulatory regions of plasticity/regeneration (e.g., Creb5, Cdc42bpa, Ppp3cc, and Atf3) genes. These findings demonstrate an unrecognized role for N-linked glycosylation as an adaptive sensor to reduced glucose availability. They further demonstrate that ER stress induced by 2-DG can, in the absence of ketosis, lead to the transcription of genes involved in plasticity and cognitive resilience as well as proteostasis.
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Affiliation(s)
- Amit Kumar
- Burke Neurological Institute and Brain and Mind Research Institute, Weill Cornell Medicine, 785 Mamaroneck Ave, White Plains, NY, USA
| | - Saravanan S Karuppagounder
- Burke Neurological Institute and Brain and Mind Research Institute, Weill Cornell Medicine, 785 Mamaroneck Ave, White Plains, NY, USA
| | - Yingxin Chen
- Burke Neurological Institute and Brain and Mind Research Institute, Weill Cornell Medicine, 785 Mamaroneck Ave, White Plains, NY, USA
| | - Carlo Corona
- Burke Neurological Institute and Brain and Mind Research Institute, Weill Cornell Medicine, 785 Mamaroneck Ave, White Plains, NY, USA
| | - Riki Kawaguchi
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Yuyan Cheng
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Mustafa Balkaya
- Burke Neurological Institute and Brain and Mind Research Institute, Weill Cornell Medicine, 785 Mamaroneck Ave, White Plains, NY, USA
| | - Botir T Sagdullaev
- Burke Neurological Institute and Brain and Mind Research Institute, Weill Cornell Medicine, 785 Mamaroneck Ave, White Plains, NY, USA; Regeneron Pharmaceuticals, Tarrytown, New York, NY, USA
| | - Zhexing Wen
- Departments of Psychiatry and Behavioral Sciences, Cell Biology, and Neurology, Emory University School of Medicine, Atlanta, GA, USA
| | - Charles Stuart
- East Tennessee State University Quillen College of Medicine, Johnson City, TN, USA
| | - Sunghee Cho
- Burke Neurological Institute and Brain and Mind Research Institute, Weill Cornell Medicine, 785 Mamaroneck Ave, White Plains, NY, USA
| | - Guo-Li Ming
- Department of Neuroscience, Perelman School for Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jürgen Tuvikene
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Tõnis Timmusk
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Daniel H Geschwind
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Rajiv R Ratan
- Burke Neurological Institute and Brain and Mind Research Institute, Weill Cornell Medicine, 785 Mamaroneck Ave, White Plains, NY, USA.
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Hang TD, Hung HM, Beckers P, Desmet N, Lamrani M, Massie A, Hermans E, Vanommeslaeghe K. Structural investigation of human cystine/glutamate antiporter system xc− (Sxc−) using homology modeling and molecular dynamics. Front Mol Biosci 2022; 9:1064199. [DOI: 10.3389/fmolb.2022.1064199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 11/15/2022] [Indexed: 12/04/2022] Open
Abstract
The cystine/glutamate antiporter system xc− (Sxc−) belongs to the SLC7 family of plasma membrane transporters. It exports intracellular glutamate along the latter’s concentration gradient as a driving force for cellular uptake of cystine. Once imported, cystine is mainly used for the production of glutathione, a tripeptide thiol crucial in maintenance of redox homeostasis and protection of cells against oxidative stress. Overexpression of Sxc− has been found in several cancer cells, where it is thought to counteract the increased oxidative stress. In addition, Sxc− is important in the central nervous system, playing a complex role in regulating glutamatergic neurotransmission and glutamate toxicity. Accordingly, this transporter is considered a potential target for the treatment of cancer as well as neurodegenerative diseases. Till now, no specific inhibitors are available. We herein present four conformations of Sxc− along its transport pathway, obtained using multi-template homology modeling and refined by means of Molecular Dynamics. Comparison with a very recently released cryo-EM structure revealed an excellent agreement with our inward-open conformation. Intriguingly, our models contain a structured N-terminal domain that is unresolved in the experimental structures and is thought to play a gating role in the transport mechanism of other SLC7 family members. In contrast to the inward-open model, there is no direct experimental counterpart for the other three conformations we obtained, although they are in fair agreement with the other stages of the transport mechanism seen in other SLC7 transporters. Therefore, our models open the prospect for targeting alternative Sxc− conformations in structure-based drug design efforts.
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Acute and Delayed Effects of Mechanical Injury on Calcium Homeostasis and Mitochondrial Potential of Primary Neuroglial Cell Culture: Potential Causal Contributions to Post-Traumatic Syndrome. Int J Mol Sci 2022; 23:ijms23073858. [PMID: 35409216 PMCID: PMC8998891 DOI: 10.3390/ijms23073858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/24/2022] [Accepted: 03/29/2022] [Indexed: 02/07/2023] Open
Abstract
In vitro models of traumatic brain injury (TBI) help to elucidate the pathological mechanisms responsible for cell dysfunction and death. To simulate in vitro the mechanical brain trauma, primary neuroglial cultures were scratched during different periods of network formation. Fluorescence microscopy was used to measure changes in intracellular free Ca2+ concentration ([Ca2+]i) and mitochondrial potential (ΔΨm) a few minutes later and on days 3 and 7 after scratching. An increase in [Ca2+]i and a decrease in ΔΨm were observed ~10 s after the injury in cells located no further than 150–200 µm from the scratch border. Ca2+ entry into cells during mechanical damage of the primary neuroglial culture occurred predominantly through the NMDA-type glutamate ionotropic channels. MK801, an inhibitor of this type of glutamate receptor, prevented an acute increase in [Ca2+]i in 99% of neurons. Pathological changes in calcium homeostasis persisted in the primary neuroglial culture for one week after injury. Active cell migration in the scratch area occurred on day 11 after neurotrauma and was accompanied by a decrease in the ratio of live to dead cells in the areas adjacent to the injury. Immunohistochemical staining of glial fibrillary acidic protein and β-III tubulin showed that neuronal cells migrated to the injured area earlier than glial cells, but their repair potential was insufficient for survival. Mitochondrial Ca2+ overload and a drop in ΔΨm may cause delayed neuronal death and thus play a key role in the development of the post-traumatic syndrome. Preventing prolonged ΔΨm depolarization may be a promising therapeutic approach to improve neuronal survival after traumatic brain injury.
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Maher P, Currais A, Schubert D. Using the Oxytosis/Ferroptosis Pathway to Understand and Treat Age-Associated Neurodegenerative Diseases. Cell Chem Biol 2020; 27:1456-1471. [PMID: 33176157 PMCID: PMC7749085 DOI: 10.1016/j.chembiol.2020.10.010] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/31/2020] [Accepted: 10/20/2020] [Indexed: 12/18/2022]
Abstract
Oxytosis was first described over 30 years ago in nerve cells as a non-excitotoxic pathway for glutamate-induced cell death. The key steps of oxytosis, including glutathione depletion, lipoxygenase activation, reactive oxygen species accumulation, and calcium influx, were identified using a combination of chemical and genetic tools. A pathway with the same characteristics as oxytosis was identified in transformed fibroblasts in 2012 and named ferroptosis. Importantly, the pathophysiological changes seen in oxytosis and ferroptosis are also observed in multiple neurodegenerative diseases as well as in the aging brain. This led to the hypothesis that this pathway could be used as a screening tool to identify novel drug candidates for the treatment of multiple age-associated neurological disorders, including Alzheimer's disease (AD). Using this approach, we have identified several AD drug candidates, one of which is now in clinical trials, as well as new target pathways for AD.
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Affiliation(s)
- Pamela Maher
- The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
| | - Antonio Currais
- The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - David Schubert
- The Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
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Ratan RR. The Chemical Biology of Ferroptosis in the Central Nervous System. Cell Chem Biol 2020; 27:479-498. [PMID: 32243811 DOI: 10.1016/j.chembiol.2020.03.007] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 02/04/2020] [Accepted: 03/09/2020] [Indexed: 12/11/2022]
Abstract
Over the past five decades, thanatology has come to include the study of how individual cells in our bodies die appropriately and inappropriately in response to physiological and pathological stimuli. Morphological and biochemical criteria have been painstakingly established to create clarity around definitions of distinct types of cell death and mechanisms for their activation. Among these, ferroptosis has emerged as a unique, oxidative stress-induced cell death pathway with implications for diseases as diverse as traumatic brain injury, hemorrhagic stroke, Alzheimer's disease, cancer, renal ischemia, and heat stress in plants. In this review, I highlight some of the formative studies that fostered its recognition in the nervous system and describe how chemical biological tools have been essential in defining events necessary for its execution. Finally, I discuss emerging opportunities for antiferroptotic agents as therapeutic agents in neurological diseases.
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Affiliation(s)
- Rajiv R Ratan
- Burke Neurological Institute at Weill Cornell Medicine, 785 Mamaroneck Avenue, White Plains, NY 10605, USA.
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Campisi A, Acquaviva R, Raciti G, Duro A, Rizzo M, Santagati NA. Antioxidant Activities of Solanum Nigrum L. Leaf Extracts Determined in in vitro Cellular Models. Foods 2019; 8:foods8020063. [PMID: 30744041 PMCID: PMC6406898 DOI: 10.3390/foods8020063] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 01/28/2019] [Accepted: 01/30/2019] [Indexed: 01/06/2023] Open
Abstract
Several medicinal foods abound in traditional medicine with antioxidant potentials that could be of importance for the management of several diseases but with little or no scientific justification to substantiate their use. Thus, the objective of this study was the assessment of the antioxidant effect of two leave extracts of Solanum nigrum L. (SN), which is a medicinal plant member of the Solanaceae family, mainly used for soup preparation in different parts of the world. Then methanolic/water (80:20) (SN1) and water (SN2) leaves extracts were prepared. The total polyphenolic content and the concentration of phenolic acids and flavones compounds were determined. In order to verify whether examined extracts were able to restore the oxidative status, modified by glutamate in primary cultures of astrocytes, the study evaluated the glutathione levels, the intracellular oxidative stress, and the cytotoxicity of SN1 and SN2 extracts. Both extracts were able to quench the radical in an in vitro free cellular system and restore the oxidative status in in vitro primary cultures of rat astroglial cells exposed to glutamate. These extracts prevented the increase in glutamate uptake and inhibited glutamate excitotoxicity, which leads to cell damage and shows a notable antioxidant property.
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Affiliation(s)
- Agata Campisi
- Department of Drug Science, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy.
| | - Rosaria Acquaviva
- Department of Drug Science, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy.
| | - Giuseppina Raciti
- Department of Drug Science, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy.
| | - Anna Duro
- Department of Biological, Geological and Environmental Sciences, University of Catania,Via A. Longo 19, 95125 Catania, Italy.
| | - Milena Rizzo
- Department of Drug Science, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy.
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8
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Aleyasin H, Karuppagounder SS, Kumar A, Sleiman S, Basso M, Ma T, Siddiq A, Chinta SJ, Brochier C, Langley B, Haskew-Layton R, Bane SL, Riggins GJ, Gazaryan I, Starkov AA, Andersen JK, Ratan RR. Antihelminthic benzimidazoles are novel HIF activators that prevent oxidative neuronal death via binding to tubulin. Antioxid Redox Signal 2015; 22:121-34. [PMID: 24766300 PMCID: PMC4281859 DOI: 10.1089/ars.2013.5595] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
AIMS Pharmacological activation of the adaptive response to hypoxia is a therapeutic strategy of growing interest for neurological conditions, including stroke, Huntington's disease, and Parkinson's disease. We screened a drug library with known safety in humans using a hippocampal neuroblast line expressing a reporter of hypoxia-inducible factor (HIF)-dependent transcription. RESULTS Our screen identified more than 40 compounds with the ability to induce hypoxia response element-driven luciferase activity as well or better than deferoxamine, a canonical activator of hypoxic adaptation. Among the chemical entities identified, the antihelminthic benzimidazoles represented one pharmacophore that appeared multiple times in our screen. Secondary assays confirmed that antihelminthics stabilized the transcriptional activator HIF-1α and induced expression of a known HIF target gene, p21(cip1/waf1), in post-mitotic cortical neurons. The on-target effect of these agents in stimulating hypoxic signaling was binding to free tubulin. Moreover, antihelminthic benzimidazoles also abrogated oxidative stress-induced death in vitro, and this on-target effect also involves binding to free tubulin. INNOVATION AND CONCLUSIONS These studies demonstrate that tubulin-binding drugs can activate a component of the hypoxic adaptive response, specifically the stabilization of HIF-1α and its downstream targets. Tubulin-binding drugs, including antihelminthic benzimidazoles, also abrogate oxidative neuronal death in primary neurons. Given their safety in humans and known ability to penetrate into the central nervous system, antihelminthic benzimidazoles may be considered viable candidates for treating diseases associated with oxidative neuronal death, including stroke.
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Affiliation(s)
- Hossein Aleyasin
- 1 Burke-Cornell Medical Research Institute , White Plains, New York
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Resch JM, Albano R, Liu X, Hjelmhaug J, Lobner D, Baker DA, Choi S. Augmented cystine-glutamate exchange by pituitary adenylate cyclase-activating polypeptide signaling via the VPAC1 receptor. Synapse 2014; 68:604-612. [PMID: 25066643 DOI: 10.1002/syn.21772] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 07/08/2014] [Accepted: 07/22/2014] [Indexed: 01/17/2023]
Abstract
In the central nervous system, cystine import in exchange for glutamate through system xc- is critical for the production of the antioxidant glutathione by astrocytes, as well as the maintenance of extracellular glutamate. Therefore, regulation of system xc- activity affects multiple aspects of cellular physiology and may contribute to disease states. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuronally derived peptide that has already been demonstrated to modulate multiple aspects of glutamate signaling suggesting PACAP may also target activity of cystine-glutamate exchange via system xc-. In this study, 24-h treatment of primary cortical cultures containing neurons and glia with PACAP concentration-dependently increased system xc- function as measured by radiolabeled cystine uptake. Furthermore, the increase in cystine uptake was completely abolished by the system xc- inhibitor, (S)-4-carboxyphenylglycine (CPG), attributing increases in cystine uptake specifically to system xc- activity. Time course and quantitative PCR results indicate that PACAP signaling may increase cystine-glutamate exchange by increasing expression of xCT, the catalytic subunit of system xc-. Furthermore, the potentiation of system xc- activity by PACAP occurs via a PKA-dependent pathway that is not mediated by the PAC1R, but rather the shared vasoactive intestinal polypeptide receptor VPAC1R. Finally, assessment of neuronal, astrocytic, and microglial-enriched cultures demonstrated that only astrocyte-enriched cultures exhibit enhanced cystine uptake following both PACAP and VIP treatment. These data introduce a novel mechanism by which both PACAP and VIP regulate system xc- activity. Synapse 68:604-612, 2014. © 2014 Wiley Periodicals, Inc.
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Affiliation(s)
- Jon M Resch
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, 53201
| | - Rebecca Albano
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, 53201
| | - Xiaoqian Liu
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, 53201
| | - Julie Hjelmhaug
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, 53201
| | - Doug Lobner
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, 53201
| | - David A Baker
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, 53201
| | - Sujean Choi
- Department of Biomedical Sciences, Marquette University, Milwaukee, Wisconsin, 53201
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GONG GU, HU LING, LIU YINGHAI, BAI SHURONG, DAI XUEMEI, YIN LIANG, SUN YANGYANG, WANG XIAOWU, HOU LICHAO. Upregulation of HIF-1α protein induces mitochondrial autophagy in primary cortical cell cultures through the inhibition of the mTOR pathway. Int J Mol Med 2014; 34:1133-40. [DOI: 10.3892/ijmm.2014.1850] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 06/26/2014] [Indexed: 11/06/2022] Open
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FGF-2 induces neuronal death through upregulation of system xc-. Brain Res 2013; 1547:25-33. [PMID: 24374066 DOI: 10.1016/j.brainres.2013.12.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 12/03/2013] [Accepted: 12/17/2013] [Indexed: 11/21/2022]
Abstract
The cystine/glutamate antiporter (system xc-) transports cystine into cell in exchange for glutamate. Fibroblast growth factor-2 (FGF-2) upregulates system xc- selectively on astrocytes, which leads to increased cystine uptake, the substrate for glutathione production, and increased glutamate release. While increased intracellular glutathione can limit oxidative stress, the increased glutamate release can potentially lead to excitotoxicity to neurons. To test this hypothesis, mixed neuronal and glial cortical cultures were treated with FGF-2. Treatment with FGF-2 for 48 h caused a significant neuronal death in these cultures. Cell death was not observed in neuronal-enriched cultures, or astrocyte-enriched cultures, suggesting the toxicity was the result of neuron-glia interaction. Blocking system xc- eliminated the neuronal death as did the AMPA/kainate receptor antagonist 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo[f]quinoxaline-2,3-dione (NBQX), but not the NMDA receptor antagonist memantine. When cultures were exposed directly to glutamate, both NBQX and memantine blocked the neuronal toxicity. The mechanism of this altered profile of glutamate receptor mediated toxicity by FGF-2 is unclear. The selective calcium permeable AMPA receptor antagonist 1-naphthyl acetyl spermine (NASPM) failed to offer protection. The most likely explanation for the results is that 48 h FGF-2 treatment induces AMPA/kainate receptor toxicity through increased system xc- function resulting in increased release of glutamate. At the same time, FGF-2 alters the sensitivity of the neurons to glutamate toxicity in a manner that promotes selective AMPA/kainate receptor mediated toxicity.
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12
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Malfa GA, Tomasello B, Sinatra F, Villaggio G, Amenta F, Avola R, Renis M. "Reactive" response evaluation of primary human astrocytes after methylmercury exposure. J Neurosci Res 2013; 92:95-103. [PMID: 24123177 DOI: 10.1002/jnr.23290] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 07/30/2013] [Accepted: 08/05/2013] [Indexed: 01/22/2023]
Abstract
Astrocytes are actively involved in brain development, in mature CNS regulation, and in brain plasticity. They play a critical role in response to cerebral injuries and toxicants through a reaction known as "reactive gliosis," which is characterized by specific structural and functional features. A large amount of literature highlights the central role of astrocytes in mediating methylmercury (MeHg) neurotoxicity. In fact, mercury is the major neurotoxic pollutant that continues to arouse interest in research because of the severe risk it poses to human health. In this article, we focus on the action of MeHg on human astrocyte (HA) reactivity. We clearly demonstrate that MeHg induces a state of cellular suffering by promoting delayed and atypical astrocyte reactivity mediated by impairment of the proliferative and trophic component of the astrocyte together with an inflammatory state. This condition is generated by negative modulation of the major proteins of the filamentous network, which is manifested by the destabilization of astrocytic cytoarchitecture. Our data confirms the toxic effects of MeHg on HA reactivity and allows us to hypothesize that the establishment of this state of suffering and the delayed onset of a typical astrocytic reactivity compromise the main protective function of HA.
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Affiliation(s)
- Giuseppe A Malfa
- Department of Drug Sciences, Biochemistry Section, University of Camerino, Camerino, Italy
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13
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Memantine rescues transient cognitive impairment caused by high-molecular-weight aβ oligomers but not the persistent impairment induced by low-molecular-weight oligomers. J Neurosci 2013; 33:9626-34. [PMID: 23739959 DOI: 10.1523/jneurosci.0482-13.2013] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Brain accumulation of soluble amyloid-β oligomers (AβOs) has been implicated in synapse failure and cognitive impairment in Alzheimer's disease (AD). However, whether and how oligomers of different sizes induce synapse dysfunction is a matter of controversy. Here, we report that low-molecular-weight (LMW) and high-molecular-weight (HMW) Aβ oligomers differentially impact synapses and memory. A single intracerebroventricular injection of LMW AβOs (10 pmol) induced rapid and persistent cognitive impairment in mice. On the other hand, memory deficit induced by HMW AβOs (10 pmol) was found to be reversible. While memory impairment in LMW oligomer-injected mice was associated with decreased hippocampal synaptophysin and GluN2B immunoreactivities, synaptic pathology was not detected in the hippocampi of HMW oligomer-injected mice. On the other hand, HMW oligomers, but not LMW oligomers, induced oxidative stress in hippocampal neurons. Memantine rescued both neuronal oxidative stress and the transient memory impairment caused by HMW oligomers, but did not prevent the persistent cognitive deficit induced by LMW oligomers. Results establish that different Aβ oligomer assemblies act in an orchestrated manner, inducing different pathologies and leading to synapse dysfunction. Furthermore, results suggest a mechanistic explanation for the limited efficacy of memantine in preventing memory loss in AD.
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Bridges R, Lutgen V, Lobner D, Baker DA. Thinking outside the cleft to understand synaptic activity: contribution of the cystine-glutamate antiporter (System xc-) to normal and pathological glutamatergic signaling. Pharmacol Rev 2012; 64:780-802. [PMID: 22759795 PMCID: PMC3400835 DOI: 10.1124/pr.110.003889] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
System x(c)(-) represents an intriguing target in attempts to understand the pathological states of the central nervous system. Also called a cystine-glutamate antiporter, system x(c)(-) typically functions by exchanging one molecule of extracellular cystine for one molecule of intracellular glutamate. Nonvesicular glutamate released during cystine-glutamate exchange activates extrasynaptic glutamate receptors in a manner that shapes synaptic activity and plasticity. These findings contribute to the intriguing possibility that extracellular glutamate is regulated by a complex network of release and reuptake mechanisms, many of which are unique to glutamate and rarely depicted in models of excitatory signaling. Because system x(c)(-) is often expressed on non-neuronal cells, the study of cystine-glutamate exchange may advance the emerging viewpoint that glia are active contributors to information processing in the brain. It is noteworthy that system x(c)(-) is at the interface between excitatory signaling and oxidative stress, because the uptake of cystine that results from cystine-glutamate exchange is critical in maintaining the levels of glutathione, a critical antioxidant. As a result of these dual functions, system x(c)(-) has been implicated in a wide array of central nervous system diseases ranging from addiction to neurodegenerative disorders to schizophrenia. In the current review, we briefly discuss the major cellular components that regulate glutamate homeostasis, including glutamate release by system x(c)(-). This is followed by an in-depth discussion of system x(c)(-) as it relates to glutamate release, cystine transport, and glutathione synthesis. Finally, the role of system x(c)(-) is surveyed across a number of psychiatric and neurodegenerative disorders.
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Affiliation(s)
- Richard Bridges
- Department of Biomedical and Pharmaceutical Sciences, University of Montana, Missoula, Montana, USA
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Liu X, Resch J, Rush T, Lobner D. Functional upregulation of system xc− by fibroblast growth factor-2. Neuropharmacology 2012; 62:901-6. [DOI: 10.1016/j.neuropharm.2011.09.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 09/13/2011] [Accepted: 09/14/2011] [Indexed: 10/17/2022]
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Mi YJ, Hou B, Liao QM, Ma Y, Luo Q, Dai YK, Ju G, Jin WL. Amino-Nogo-A antagonizes reactive oxygen species generation and protects immature primary cortical neurons from oxidative toxicity. Cell Death Differ 2012; 19:1175-86. [PMID: 22261619 DOI: 10.1038/cdd.2011.206] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Nogo-A is originally identified as an inhibitor of axon regeneration from the CNS myelin. Nogo-A is mainly expressed by oligodendrocytes, and also by some neuronal subpopulations, particularly in the developing nervous system. Although extensive studies have uncovered regulatory roles of Nogo-A in neurite outgrowth inhibition, precursor migration, neuronal homeostasis, plasticity and neurodegeneration, its cell-autonomous functions in neurons are largely uncharacterized. Here, we show that HIV-1 trans-activating-mediated amino-Nogo-A protein transduction into cultured primary cortical neurons achieves an almost complete neuroprotection against oxidative stress induced by exogenous hydrogen peroxide (H(2)O(2)). Endogenously expressed neuronal Nogo-A is significantly downregulated upon H(2)O(2) treatment. Furthermore, knockdown of Nogo-A results in more susceptibility to acute oxidative insults and markedly increases neuronal death. Interacting with peroxiredoxin 2 (Prdx2), amino-Nogo-A reduces reactive oxygen species (ROS) generation and extracellular signal-regulated kinase phosphorylation to exert neuroprotective effects. Structure-function mapping experiments reveal that, out of NiG-Δ20, a novel region comprising residues 290-562 of amino-Nogo-A is indispensable for preventing oxidative neuronal death. Moreover, mutagenesis analysis confirms that cysteine residues 424, 464 and 559 are involved in the inhibition of ROS generation and neuroprotective role of amino-Nogo-A. Our data suggest that neuronal Nogo-A might play a cell-autonomous role in improving neuronal survival against oxidative insult through interacting with Prdx2 and scavenging of ROS.
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Affiliation(s)
- Y-J Mi
- Institute of Neurosciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, China
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Characterization of Novel Neuroprotective Lipid Analogues for the Treatment of Stroke. Transl Stroke Res 2012. [DOI: 10.1007/978-1-4419-9530-8_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Montenegro L, Campisi A, Sarpietro MG, Carbone C, Acquaviva R, Raciti G, Puglisi G. In vitro evaluation of idebenone-loaded solid lipid nanoparticles for drug delivery to the brain. Drug Dev Ind Pharm 2011; 37:737-46. [PMID: 21204752 DOI: 10.3109/03639045.2010.539231] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
CONTEXT Solid lipid nanoparticles (SLN) are regarded as interesting drug delivery systems and their preparation techniques have gained a great deal of attention. OBJECTIVE To evaluate the feasibility of preparing idebenone (IDE) loaded SLN from O/W microemulsions by the phase-inversion temperature (PIT) method. Since SLN have been proposed to improve drug delivery to the brain, IDE was chosen as model drug due to its activity in the treatment of neurodegenerative diseases. MATERIALS AND METHODS Cetyl palmitate was used as solid lipid to prepare SLN containing two surfactant/cosurfactant mixtures, isoceteth-20/glyceryl oleate (SLN A) and ceteth-20/glyceryl oleate (SLN B) by the PIT method. RESULTS AND DISCUSSION All the formulations tested showed a mean particle diameter ranging from 30 to 95 nm and a single peak in size distribution. Stability tests showed that SLN B were more stable than SLN A. IDE release was dependent both on the type of primary surfactant used and the amount of loaded drug. IDE-loaded SLN were effective in inhibiting 2,2'-azobis-(2-amidinopropane)dihydrochloride (APPH)-induced lactic dehydrogenase (LDH) release and reactive oxygen species (ROS) production in primary cultures of astrocytes obtained from rat cerebral cortex. It is noteworthy that SLN B2 (containing ceteth-20 as primary surfactant and 0.7% w/w IDE) were able to prevent entirely both the LDH release and ROS production induced by APPH. CONCLUSION The PIT method provided SLN with good technological properties. The tested SLN could be regarded as interesting carriers to overcome the blood brain barrier and increase the efficacy of the loaded drug.
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Affiliation(s)
- Lucia Montenegro
- Department of Pharmaceutical Sciences, University of Catania, Catania, Italy.
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Pignatello R, Acquaviva R, Campisi A, Raciti G, Musumeci T, Puglisi G. Effects of liposomal encapsulation on the antioxidant activity of lipophilic prodrugs of idebenone. J Liposome Res 2010; 21:46-54. [DOI: 10.3109/08982101003735996] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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20
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Campisi A, Gulino M, Acquaviva R, Bellia P, Raciti G, Grasso R, Musumeci F, Vanella A, Triglia A. Reactive oxygen species levels and DNA fragmentation on astrocytes in primary culture after acute exposure to low intensity microwave electromagnetic field. Neurosci Lett 2010; 473:52-5. [DOI: 10.1016/j.neulet.2010.02.018] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2010] [Revised: 02/05/2010] [Accepted: 02/06/2010] [Indexed: 10/19/2022]
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Wee XK, Ng KS, Leung HW, Cheong YP, Kong KH, Ng FM, Soh W, Lam Y, Low CM. Mapping the high-affinity binding domain of 5-substituted benzimidazoles to the proximal N-terminus of the GluN2B subunit of the NMDA receptor. Br J Pharmacol 2010; 159:449-61. [PMID: 20082612 DOI: 10.1111/j.1476-5381.2009.00549.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND AND PURPOSE N-methyl-D-aspartate (NMDA) receptors represent an attractive drug target for the treatment of neurological and neurodegenerative disorders associated with glutamate-induced excitotoxicity. The aim of this study was to map the binding domain of high affinity 5-substituted benzimidazole derivatives [N-{2-[(4-benzylpiperidin-1-yl)methyl]benzimidazol-5-yl}methanesulphonamide (XK1) and N-[2-(4-phenoxybenzyl)benzimidazol-5-yl]methanesulphonamide (XK2)] on the GluN2B subunit of the NMDA receptor. EXPERIMENTAL APPROACH The pharmacological antagonistic profiles of XK1 and XK2 were assessed using in vitro rat primary cerebrocortical neurones and two-electrode voltage clamp on Xenopus oocytes expressing heterologous GluN1/GluN2B receptors. Direct ligand binding was determined using the recombinant amino-terminal domain (ATD) of GluN2B. KEY RESULTS XK1 and XK2 effectively protected against NMDA-induced excitotoxicity in rat primary cortical neurones. Low concentrations of XK1 (10 nM) and XK2 (1 nM) significantly reversed neuronal death. Both compounds failed to inhibit currents measured from oocytes heterologously expressing GluN1-1a subunit co-assembled with the ATD-deleted GluN2B subunit. XK1 and XK2 showed specific binding to recombinant protein of GluN2B ATD with low nanomolar affinities. Several residues in the recombinant ATD of GluN2B were identified to be critical for conferring XK1 and XK2 sensitivity. The inhibitory effects of XK1 and XK2 were pH-sensitive, being increased at acidic pH. CONCLUSIONS AND IMPLICATIONS These results demonstrate that XK1 and XK2 are effective neuroprotective agents in vitro and indicate that 5-substituted benzimidazole derivatives inhibit GluN1/GluN2B receptors via direct binding to the ATD of the GluN2B subunit. These compounds represent valuable alternatives to the classical antagonist ifenprodil as pharmacological tools for studying GluN2B-containing NMDA receptors.
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Affiliation(s)
- X-K Wee
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Republic of Singapore
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Santos IMDS, de Freitas RLM, da Silva EP, Feitosa CM, Saldanha GB, Souza GF, Tomé ADR, Feng D, de Freitas RM. Effects of ubiquinone on hydroperoxide concentration and antioxidant enzymatic activities in the rat hippocampus during pilocarpine-induced seizures. Brain Res 2009; 1315:33-40. [PMID: 20034476 DOI: 10.1016/j.brainres.2009.12.037] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Revised: 12/09/2009] [Accepted: 12/12/2009] [Indexed: 11/27/2022]
Abstract
Recent researches have shown that antioxidant compounds may have certain neuroprotective effect against the neurotoxicity of seizures at cellular level. Ubiquinone (UQ), an antioxidant compound, exhibits a wide range of therapeutic effects that are attributed to its potent antioxidant capacity. The objective of the present study was to evaluate the neuroprotective effects of UQ in rats, against the observed oxidative stress during seizures induced by pilocarpine. Wistar rats were treated with either 0.9% saline (i.p., control group), UQ (5, 10 or 20 mg/kg, i.p., UQ5, UQ10 and UQ20 groups), pilocarpine (400 mg/kg, i.p., P400 group), or co-administration of pilocarpine with UQ group rats 30 min prior to UQ administration. After the treatments all groups were observed for 24 h. The antioxidant enzymatic activities as well as the hydroperoxide concentrations were measured using spectrophotometric methods and the results were analyzed. In pilocarpine group there was a significant increase in hydroperoxides concentration and glutathione peroxidase activity. However, no alteration was observed in superoxide dismutase and catalase activities. Antioxidant treatment significantly reduced the hydroperoxide content and increased the superoxide dismutase, catalase and glutathione peroxidase activities in rat hippocampus during seizures induced by pilocarpine. Our findings strongly support the hypothesis that oxidative stress in hippocampus occurs during seizures induced by pilocarpine, which indicates that brain damage induced by the oxidative process plays a crucial role in seizures pathogenic consequences. Our result also suggests that ubiquinone can exert significant neuroprotective effects that might be useful in the treatment of neurodegenerative diseases.
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Liu Y, Schubert DR. The specificity of neuroprotection by antioxidants. J Biomed Sci 2009; 16:98. [PMID: 19891782 PMCID: PMC2779189 DOI: 10.1186/1423-0127-16-98] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Accepted: 11/05/2009] [Indexed: 12/23/2022] Open
Abstract
Background Reactive oxygen species (ROS) play an important role in aging and age-related diseases such as Parkinson's disease and Alzheimer's disease. Much of the ROS production under conditions of toxic stress is from mitochondria, and multiple antioxidants prevent ROS accumulation. The aim of this study is to examine the specificity of the interaction between the antioxidants and ROS production in stressed cells. Methods Using fluorescent dyes for ROS detection and mitochondrial inhibitors of known specificities, we studied ROS production under three conditions where ROS are produced by mitochondria: oxidative glutamate toxicity, state IV respiration induced by oligomycin, and tumor necrosis factor-induced cell death. Results We demonstrated that there are at least four mitochondrial ROS-generating sites in cells, including the flavin mononucleotide (FMN) group of complex I and the three ubiquinone-binding sites in complexes I, II and III. ROS production from these sites is modulated in an insult-specific manner and the sites are differentially accessible to common antioxidants. Conclusion The inhibition of ROS accumulation by different antioxidants is specific to the site of ROS generation as well as the antioxidant. This information should be useful for devising new interventions to delay aging or treat ROS-related diseases.
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Affiliation(s)
- Yuanbin Liu
- Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies,10010 N, Torrey Pines Road, La Jolla, California 92037-1099 USA.
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Influences of Flavonoids on Erythrocyte Membrane and Metabolic Implication Through Anionic Exchange Modulation. J Membr Biol 2009; 230:163-71. [DOI: 10.1007/s00232-009-9197-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Accepted: 08/06/2009] [Indexed: 10/20/2022]
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Pulse inhibition of histone deacetylases induces complete resistance to oxidative death in cortical neurons without toxicity and reveals a role for cytoplasmic p21(waf1/cip1) in cell cycle-independent neuroprotection. J Neurosci 2008; 28:163-76. [PMID: 18171934 DOI: 10.1523/jneurosci.3200-07.2008] [Citation(s) in RCA: 128] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Histone deacetylase (HDAC) inhibitors are currently in human clinical trials as antitumor drugs because of their ability to induce cell dysfunction and death in cancer cells. The toxic effects of HDAC inhibitors are also apparent in cortical neurons in vitro, despite the ability of these agents to induce significant protection in the cells they do not kill. Here we demonstrate that pulse exposure of cortical neurons (2 h) in an in vitro model of oxidative stress results in durable neuroprotection without toxicity. Protection was associated with transcriptional upregulation of the cell cycle inhibitor, p21(waf1/cip1), both in this model and in an in vivo model of permanent ischemia. Transgenic overexpression of p21(waf1/cip1) in neurons can mimic the protective effect of HDAC inhibitors against oxidative stress-induced toxicity, including death induced by glutathione depletion or peroxide addition. The protective effect of p21(waf1/cip1) in the context of oxidative stress appears to be unrelated to its ability to act in the nucleus to inhibit cell cycle progression. However, although p21(waf1/cip1) is sufficient for neuroprotection, it is not necessary for HDAC inhibitor neuroprotection, because these agents can completely protect neurons cultured from p21(waf1/cip1)-null mice. Together these findings demonstrate (1) that pulse inhibition of HDACs in cortical neurons can induce neuroprotection without apparent toxicity; (2) that p21(waf1/cip1) is sufficient but not necessary to mimic the protective effects of HDAC inhibition; and (3) that oxidative stress in this model induces neuronal cell death via cell cycle-independent pathways that can be inhibited by a cytosolic, noncanonical action of p21(waf1/cip1).
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Effects of disrupting calcium homeostasis on neuronal maturation: early inhibition and later recovery. Cell Mol Neurobiol 2008; 28:389-409. [PMID: 18196452 DOI: 10.1007/s10571-007-9255-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2007] [Accepted: 12/14/2007] [Indexed: 10/22/2022]
Abstract
It has become increasingly clear that agents that disrupt calcium homeostasis may also be toxic to developing neurons. Using isolated primary neurons, we sought to understand the neurotoxicity of agents such as MK801 (which blocks ligand-gated calcium entry), BAPTA (which chelates intracellular calcium), and thapsigargin (TG; which inhibits the endoplasmic reticulum Ca(2+)-ATPase pump). Thus, E18 rat cortical neurons were grown for 1 day in vitro (DIV) and then exposed to vehicle (0.1% DMSO), MK801 (0.01-20 microM), BAPTA (0.1-20 microM), or TG (0.001-1 microM) for 24 h. We found that all three agents could profoundly influence early neuronal maturation (growth cone expansion, neurite length, neurite complexity), with the order of potency being MK801 < BAPTA < TG. We next asked if cultures exposed to these agents were able to re-establish their developmental program once the agent was removed. When we examined network maturity at 4 and 7 DIV, the order of recovery was MK801 > BAPTA > TG. Thus, mechanistically distinct ways of disrupting calcium homeostasis differentially influenced both short-term and long-term neuronal maturation. These observations suggest that agents that act by altering intracellular calcium and are used in obstetrics or neonatology may be quite harmful to the still-developing human brain.
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Gong QH, Wang Q, Shi JS, Huang XN, Liu Q, Ma H. Inhibition of caspases and intracellular free Ca2+ concentrations are involved in resveratrol protection against apoptosis in rat primary neuron cultures. Acta Pharmacol Sin 2007; 28:1724-30. [PMID: 17959022 DOI: 10.1111/j.1745-7254.2007.00666.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
AIM To investigate the influence of resveratrol (Res), a nutritional antioxidant, on the inhibition of apoptosis in rat primary neuron cultures. METHODS The cultured cortical neurons of neonatal Sprague-Dawley rats were pretreated with Res (0.1, 1.0, and 10.0 micromol/L) and oxygen-glucose deprivation/reperfusion (OGD/RP) with oxygen and glucose were initiated at d 10 in vitro. Neuronal apoptosis was determined by flow cytometry, and morphological changes of neurons were observed by an electron microscope. For the mechanism studies, the intracellular free calcium concentration ([Ca2+]i) and the transcription of caspases-3 and -12 in neurons were detected by Fura 2/AM loading and real-time RT-PCR, respectively. RESULTS OGD/RP insult could induce an increase in the apoptotic rate of neurons (from 11.1% to 49.0%), and elicit an obvious morphological change in neurons; pretreatments with Res (0.1, 1.0, and 10.0 micromol/L, respectively) significantly reduced the elevated rate of apoptosis to 41.7%, 40.8%, and 37.4%, respectively, and ameliorated the neuronal morphological injury. Similarly, the OGD/RP insult obviously elicited the elevated levels of the [Ca2+]i and the expressions of caspases-3 and -12 mRNA in neurons. Res pretreatments markedly depressed the neuronal abnormal elevation of [Ca2+]i and the overexpression of caspases-3 and -12 mRNA in a concentration-dependent manner. CONCLUSION Res can attenuate the rat cortical neuronal apoptosis induced by OGD/RP. The mechanisms are, at least partly, due to the inhibition of the calcium overload and the overexpression of caspases-3 and -12 mRNA.
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Affiliation(s)
- Qi-hai Gong
- Department of Pharmacology, Zunyi Medical College, Zunyi 563000, China.
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Brewer LD, Thibault O, Staton J, Thibault V, Rogers JT, Garcia-Ramos G, Kraner S, Landfield PW, Porter NM. Increased vulnerability of hippocampal neurons with age in culture: temporal association with increases in NMDA receptor current, NR2A subunit expression and recruitment of L-type calcium channels. Brain Res 2007; 1151:20-31. [PMID: 17433272 DOI: 10.1016/j.brainres.2007.03.020] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 02/24/2007] [Accepted: 03/05/2007] [Indexed: 11/20/2022]
Abstract
Excessive glutamate (Glu) stimulation of the NMDA-R is a widely recognized trigger for Ca(2+)-mediated excitotoxicity. Primary neurons typically show a large increase in vulnerability to excitotoxicity with increasing days in vitro (DIV). This enhanced vulnerability has been associated with increased expression of the NR2B subunit or increased NMDA-R current, but the detailed age-courses of these variables in primary hippocampal neurons have not been compared in the same study. Further, it is not clear whether the NMDA-R is the only source of excess Ca(2+). Here, we used primary hippocampal neurons to examine the age dependence of the increase in excitotoxic vulnerability with changes in NMDA-R current, and subunit expression. We also tested whether L-type voltage-gated Ca(2+) channels (L-VGCCs) contribute to the enhanced vulnerability. The EC(50) for Glu toxicity decreased by approximately 10-fold between 8-9 and 14-15 DIV, changing little thereafter. Parallel experiments found that during the same period both amplitude and duration of NMDA-R current increased dramatically; this was associated with an increase in protein expression of the NR1 and NR2A subunits, but not of the NR2B subunit. Compared to MK-801, ifenprodil, a selective NR2B antagonist, was less effective in protecting older than younger neurons from Glu insult. Conversely, nimodipine, an L-VGCC antagonist, protected older but not younger neurons. Our results indicate that enhanced excitotoxic vulnerability with age in culture was associated with a substantial increase in NMDA-R current, concomitant increases in NR2A and NR1 but not NR2B subunit expression, and with apparent recruitment of L-VGCCs into the excitotoxic process.
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Affiliation(s)
- Lawrence D Brewer
- Department of Molecular and Biomedical Pharmacology, Chandler Medical Center, University of Kentucky, Lexington, KY 40536-0298, USA
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Xu L, Zhao Y, Zhan SQ, Tang XD, Guo Y, Wang HS, Yang C. Temporal and spatial expression of preprotachykinin A mRNA in the developing filial mice brain after maternal administration of monosodium glutamate at a late stage of pregnancy. Neuroscience 2007; 145:974-80. [PMID: 17307297 DOI: 10.1016/j.neuroscience.2006.12.029] [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: 07/31/2006] [Revised: 12/06/2006] [Accepted: 12/12/2006] [Indexed: 01/21/2023]
Abstract
In the early stages of brain development, exposure of excessive monosodium glutamate (MSG) to neurons causes animal functional and behavioral disorders in adulthood. To investigate the effects of excessive MSG during pregnancy on the neurons in the developing brain, in situ hybridization was used. In mice, the expression of preprotachykinin A mRNA (PPT A mRNA) was assessed in neurons of in the brain after MSG treatment. Brain tissue sections were hybridized with specific digoxigenin-labeled RNA probes. The number of cells that expressed PPT A mRNA gradually decreased from 10-day-old (10d) to 60-day-old (60d) MSG-treated and normal animals. In the MSG-treated and normal mice, the PPT A mRNA-positive neurons almost disappeared in 90-day-old (90d) mice. The expression of PPT A mRNA significantly decreased at 10d in most of the brain regions of MSG-treated mice including the cerebral cortex (CC), hippocampal subregions of CA1, CA2 (CA1, CA2), habenula nucleus (HAB), hypothalamic periventricular nucleus (PE), hypothalamic arcuate nucleus (AR), median eminence (ME), amygdala nucleus (AMY), endopiriform nucleus (EN), and hypothalamic ventromedial nucleus (VMH) and dorsomedial nucleus (DMH). In the hippocampal CA4 subregions (CA4), paraventricular nucleus (PV) and caudate putamen (CPU), however, they were not significantly altered. Furthermore, in CC, hippocampal CA3 subregion (CA3), PE and EN regions the number of PPT A mRNA-positive neurons decreased at 20 days old (20d), but increased significantly in CA2 and CPU. At 30 days old (30d), the positive neuron number decreased in AMY, and they did not change in other regions. At 60d, the number of positive neurons significantly decreased in PV and ME, but increased in AMY. In the other observed regions, no changes were found. These results show that maternal administration of excessive MSG at a late stage of pregnancy significantly decreases PPT A mRNA expression in most of the brain regions of filial mice. This suggests that glutamate-induced excitotoxicity may affect the metabolism of precursors of substance P in developing brain neurons. The present study provides insights into the plasticity and vulnerability of neuron in different brain regions to glutamate excitotoxicity.
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Affiliation(s)
- L Xu
- Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an Jiaotong University, Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi, China
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Shang L, Liu J, Zhu Q, Zhao L, Feng Y, Wang X, Cao W, Xin H. Gypenosides protect primary cultures of rat cortical cells against oxidative neurotoxicity. Brain Res 2006; 1102:163-74. [PMID: 16806111 DOI: 10.1016/j.brainres.2006.05.035] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Revised: 04/30/2006] [Accepted: 05/02/2006] [Indexed: 10/24/2022]
Abstract
Gypenosides (GPs) were tested for their ability to protect primary cultures of immature cortical cells against oxidative glutamate toxicity. In immature neural cells, glutamate cytotoxicity is known to be mediated by the inhibition of cystine uptake, leading to depletion of intracellular glutathione (GSH). The depletion of GSH impairs cellular antioxidant defenses resulting in oxidative stress and cell death. We found that pretreatment with GPs (100-400 microg/ml) significantly protected cells from glutamate-induced cell death. It was therefore of interest to investigate whether GPs protect cortical cells against glutamate-induced oxidative injury through preventing GSH depletion. Results show that GPs significantly up-regulated mRNAs encoding gamma-glutamylcysteine synthetase (gamma-GCS) and glutathione reductase (GR) and enhanced their activities for GSH synthesis as well as recycle. Furthermore, GPs lowered the consumption of GSH through decreased accumulation of intracellular peroxides, leading to an increase in the intracellular GSH content. GPs were also found to prevent lipid peroxidation and reduce the influx of Ca(2+) which routinely follows glutamate oxidative challenge. GPs treatment significantly blocked glutamate-induced decrease in levels of Bcl-2 and increase in Bax, leading to a decrease in glutamate-induced apoptosis. Thus, we conclude that GPs protect cortical cells by multiple antioxidative actions via enhancing intracellular GSH, suppressing glutamate-induced cytosolic Ca(2+) elevation and blocking glutamate-induced apoptosis. The novel role of GPs implies their remarkable preventative and therapeutic potential in treatment of neurological diseases involving glutamate and oxidative stress.
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Affiliation(s)
- Linshan Shang
- Institute of Medical Genetics, School of Medicine, Shandong University, Jinan, PR China
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Monnerie H, Le Roux PD. Glutamate receptor agonist kainate enhances primary dendrite number and length from immature mouse cortical neurons in vitro. J Neurosci Res 2006; 83:944-56. [PMID: 16498632 DOI: 10.1002/jnr.20805] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Glutamate is an important regulator of dendrite development that may inhibit, (during ischemic injury), or facilitate (during early development) dendrite growth. Previous studies have reported mainly on the N-methyl-D-aspartate (NMDA) receptor-mediated dendrite growth-promoting effect of glutamate. In this study, we examined how the non-NMDA receptor agonist kainate influenced dendrite growth. E18 mouse cortical neurons were grown for 3 days in vitro and immunolabeled with anti-microtubule-associated protein 2 (MAP2) and anti-neurofilament (NF-H), to identify dendrites and axons, respectively. Exposure of cortical neurons to kainate increased dendrite growth without affecting neuron survival. This effect was dose-dependent, reversible and blocked by the alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionate (AMPA)/kainate receptor antagonist NBQX and the low-affinity kainate receptor antagonist NS-102, but not by the AMPA receptor antagonist CFM-2. In addition, the NMDA receptor antagonist MK-801 had no effect on kainate-induced dendrite growth. Immunolabeling and Western blot analysis of kainate receptors using antibodies against the GluR6 and KA2 subunits, demonstrated that the immature cortical neurons used in this study express kainate receptor proteins. These results suggest that kainate-induced non-NMDA receptor activation promotes dendrite growth, and in particular primary dendrite number and length, from immature cortical neurons in vitro, and that kainate receptors may be directly involved in this process. Furthermore, these data support the possibility that like NMDA receptors, kainate receptor activation may also contribute to early neurite growth from cortical neurons in vitro.
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Affiliation(s)
- Hubert Monnerie
- Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania 19107, USA
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Russo A, Troncoso N, Sanchez F, Garbarino JA, Vanella A. Propolis protects human spermatozoa from DNA damage caused by benzo[a]pyrene and exogenous reactive oxygen species. Life Sci 2006; 78:1401-6. [PMID: 16457855 DOI: 10.1016/j.lfs.2004.10.085] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Accepted: 08/25/2004] [Indexed: 01/10/2023]
Abstract
Many environmental, physiological and genetic factors have been implicated in defective sperm function, the most common cause of infertility. In addition, sperm preparation techniques such as centrifugation, used prior to in vitro fertilization, are associated with the generation of reactive oxygen species (ROS) and an increase in the level of DNA damage. Factors that can offer spermatozoa protection are, therefore, of great importance. This study was designed to examine in vitro the effect of a Chilean propolis ethanolic extract on human spermatozoa treated with benzo[a]pyrene and exogenous reactive oxygen species. Our experimental evidence demonstrated that the natural drug under investigation is able to protect genomic DNA by damage induced by benzo[a]pyrene, hydrogen peroxide (H2O2) and hydrogen peroxide in combination with adenosine 5'-diphosphate (ADP) and ferrous sulfate (FeSO4), determining a significant reduction of the intracellular oxidants. An increase in membrane damage, measured by monitoring the formation of thiobarbituric acid-reactive substances (TBARS) and lactic dehydrogenase (LDH) release, was observed only in sperm treated with H2O2, ADP and FeSO4. The propolis extract was shown to possess the capacity to protect sperm membrane from the deleterious action of oxidative attack, reducing TBARS formation and LDH release. In summary, our results evidence that the protective effect exhibited by this natural compound in human spermatozoa is correlated, at least in part, to the antioxidant capacity of its active components, and suggest that propolis may have a role in protection against male infertility.
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Affiliation(s)
- A Russo
- Department of Biological Chemistry, Medical Chemistry and Molecular Biology, University of Catania, v.le A. Doria 6, 95125 Catania, Italy.
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Burdo J, Dargusch R, Schubert D. Distribution of the cystine/glutamate antiporter system xc- in the brain, kidney, and duodenum. J Histochem Cytochem 2006; 54:549-57. [PMID: 16399997 DOI: 10.1369/jhc.5a6840.2006] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
System x(c)(-), one of the main transporters responsible for central nervous system cystine transport, is comprised of two subunits, xCT and 4F2hc. The transport of cystine into cells is rate limiting for glutathione synthesis, the major antioxidant and redox cofactor in the brain. Alterations in glutathione status are prevalent in numerous neurodegenerative diseases, emphasizing the importance of proper cystine homeostasis. However, the distribution of xCT and 4F2hc within the brain and other areas has not been described. Using specific antibodies, both xCT and 4F2hc were localized predominantly to neurons in the mouse and human brain, but some glial cells were labeled as well. Border areas between the brain proper and periphery including the vascular endothelial cells, ependymal cells, choroid plexus, and leptomeninges were also highly positive for the system x(c)(-) components. xCT and 4F2hc are also present at the brush border membranes in the kidney and duodenum. These results indicate that system x(c)(-) is likely to play a role in cellular health throughout many areas of the brain as well as other organs by maintaining intracellular cystine levels, thereby resulting in low levels of oxidative stress.
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Affiliation(s)
- Joseph Burdo
- Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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Matsumoto M, Sasaki T, Nagashima H, Ahn ES, Young W, Kodama N. Effects of N-methyl-d-aspartate, glutamate, and glycine on the dorsal column axons of neonatal rat spinal cord: in vitro study. Neurol Med Chir (Tokyo) 2005; 45:73-80, discussion 81. [PMID: 15722604 DOI: 10.2176/nmc.45.73] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The effects of N-methyl-D-aspartate (NMDA), glutamate, and glycine on the developmental axons of the neonatal rat spinal cord were investigated. Isolated dorsal column preparations from postnatal day (PN) 0 to 14 Long-Evans hooded rats (n = 119) were used in vitro. Compound action potentials (CAPs) were recorded from the cuneate and gracile fasciculi with a glass micropipette electrode. NMDA (100 microM) significantly increased CAP amplitude in PN 0-6 cords by 21.5 +/- 9.2% (mean +/- standard error of the mean, p < 0.001, n = 8) and in PN 7-14 cords by 6.7 +/- 6.6% (p < 0.001, n = 10). NMDA (10 microM) significantly increased the CAP amplitude by 6.3 +/- 2.9% in PN 0-6 cords (p < 0.01, n = 10). The increase of CAP amplitude induced by NMDA (100 microM) in PN 0-6 cords was significantly greater than that in PN 7-14 cords (p < 0.005). Glutamate (100 microM) significantly increased the CAP amplitude by 8.8 +/- 8.1% in PN 0-6 cords (p < 0.001, n = 29) and 6.7 +/- 7.5% in PN 7-14 cords (p < 0.01, n = 14), and glutamate (10 microM) significantly increased by 6.3 +/- 2.9% in PN 0-6 cords (p < 0.01, n = 21). The amplitudes induced by glutamate (100 microM or 10 microM) did not significantly differ between PN 0-6 and PN 7-14 cords. Application of glycine (100 microM) did not significantly alter CAP amplitudes induced by NMDA (100 microM or 10 microM) and glutamate (100 microM or 10 microM). D(-)-2-amino-5-phosphonopentanoic acid (NMDA receptor antagonist) blocked the effects of NMDA and glutamate. These results suggest that NMDA receptor is present on afferent dorsal column axons and may modulate axonal excitability, especially during the 1st week after birth.
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Affiliation(s)
- Masato Matsumoto
- W.M. Keck Center for Collaborate Neuroscience, Rutgers-The State University of New Jersey, Piscataway, NJ, USA.
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Paolino D, Iannone M, Cardile V, Renis M, Puglisi G, Rotiroti D, Fresta M. Tolerability and improved protective action of idebenone-loaded pegylated liposomes on ethanol-induced injury in primary cortical astrocytes. J Pharm Sci 2005; 93:1815-27. [PMID: 15176069 DOI: 10.1002/jps.20088] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The potential therapeutic advantages of the encapsulation of idebenone within pegylated liposomes were investigated in vitro on primary cortical astrocytes of rats. In particular, both the concentration-dependent effects and the therapeutic effectiveness toward excitotoxic injury, elicited by chronic treatment with ethanol (100 microM) for 12 days, were evaluated. The following parameters were taken into consideration to assay free or liposomally entrapped idebenone: lactic dehydrogenase release, respiratory capacity measured by tetrazolium salt conversion, glutamine synthetase, and the levels of constitutive and inducible 70-kDa heat shock proteins. To evaluate the effects on astrocytes, three different drug concentrations were used (0.5 microM, 5 microM, and 50 microM). At the highest concentration used (50 microM), a toxic effect of the free and liposomally entrapped drug was observed. Toxic effects seem to be due to a cellular membrane perturbation, as demonstrated by (45)Ca(2+) permeation. The therapeutic effect of free or liposomally entrapped idebenone on ethanol-induced injury of primary cortical astrocytes was evaluated as a function of the drug concentration. The drug liposome formulation was much more effective than the free drug in counteracting the ethanol-induced damage in astrocytes, i.e., 10-times-lower doses of liposomally entrapped idebenone are able to provide a greater protective action than the free drug. The improved action of idebenone-loaded liposomes is probably due to the greater drug bioavailability at the cellular level.
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Affiliation(s)
- Donatella Paolino
- Department of Pharmaceutical Sciences, University of Catania, Viale Andrea Doria n. 6, I-95125 Catania, Italy
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36
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Renis M, Cardile V, Grasso S, Palumbo M, Scifo C. Switching off HSP70 and i-NOS to study their role in normal and H2O2-stressed human fibroblasts. Life Sci 2004; 74:757-69. [PMID: 14654168 DOI: 10.1016/j.lfs.2003.07.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
i-NOS and HSP70 antisense oligonucleotides were used to study the role of the two well known stress-regulated molecules on cell survival of both untreated control, and H2O2-stressed human fibroblasts. Cell survival was assessed either by LDH release or by MTT assay. The levels of cytosolic i-NOS and HSP70 were tested by using immunoblotting analysis, and reactive oxygen species (ROS) production was quantified. Compared to the values observed in untreated control cells, anti HSP70-transfected human fibroblasts showed an increase in ROS production, i-NOS level and LDH release. The addition of 0.12 mM H2O2 for 20 min. to the HSP70-deprived fibroblasts did not modify the percentage of LDH release observed in H2O2 stressed cells, but reduced cell viability increasing both ROS production and i-NOS level. Anti i-NOS-transfected fibroblasts, compared to the control untreated cells, showed no modification in ROS production, while cell survival was improved. When treated with H2O2 the i-NOS depleted cells counteracted ROS formation as well as LDH release but negatively affected cell viability and HSP70 levels, compared to the results obtained with H2O2 alone-treated fibroblasts. The data indicates that the induced decrease in HSP70 level in oxidative stress conditions makes fibroblasts more prone to oxidative injury and also increases i-NOS level. Whereas in one way the forced decrease in i-NOS expression seems to counteract ROS production stimulated by the oxidative insult in the cells, in another way, since it causes a decrease in HSP70 expression as well as in cell viability, it seems to activate some unidentified pathways affecting cell demise.
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Affiliation(s)
- Marcella Renis
- Department of Biological Chemistry, Medicinal Chemistry and Molecular Biology, University of Catalina, Viale A. Doria, 6, 95125 Catania, Italy.
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37
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Monnerie H, Shashidhara S, Le Roux PD. Effect of excess extracellular glutamate on dendrite growth from cerebral cortical neurons at 3 days in vitro: Involvement of NMDA receptors. J Neurosci Res 2004; 74:688-700. [PMID: 14635220 DOI: 10.1002/jnr.10797] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Glutamate is an important regulator of dendrite development; however, during cerebral ischemia, massive glutamate release can lead to neurodegeneration and death. An early consequence of glutamate excitotoxicity is dendrite injury, which often precedes cell death. We examined the effect of glutamate on dendrite growth from embryonic day 18 (E18) mouse cortical neurons grown for 3 days in vitro (DIV) and immunolabeled with anti-microtubule-associated protein (MAP)2 and anti-neurofilament (NF)-H, to identify dendrites and axons, respectively. Cortical neurons exposed to excess extracellular glutamate (100 microM) displayed reduced dendrite growth, which occurred in the absence of cell death. This effect was mimicked by the ionotropic glutamate receptor agonist N-methyl-D-aspartate (NMDA) and blocked by the ionotropic glutamate receptor antagonist kynurenic acid and the NMDA receptor-specific antagonist MK-801. The non-NMDA receptor agonist AMPA, however, did not affect process growth. Neither NMDA nor AMPA influenced neuron survival. Immunolabeling and Western blot analysis of NMDA receptors using antibodies against the NR1 subunit, demonstrated that immature cortical neurons used in this study, express NMDA receptors. These results suggest that excess glutamate decreases dendrite growth through a mechanism resulting from NMDA receptor subclass activation. Furthermore, these data support the possibility that excess glutamate activation of NMDA receptors mediate both cell death in mature neurons and the inhibitory effect of excess glutamate on dendrite growth in immature neurons or in the absence of cell death.
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Affiliation(s)
- Hubert Monnerie
- Department of Neurosurgery, University of Pennsylvania, Philadelphia
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Russo A, Izzo AA, Borrelli F, Renis M, Vanella A. Free radical scavenging capacity and protective effect of Bacopa monniera L. on DNA damage. Phytother Res 2003; 17:870-5. [PMID: 13680815 DOI: 10.1002/ptr.1061] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Bacopa monniera L. (family Scrophulariaceae) (BM) is an Ayurvedic medicine, clinically used for memory enhancing, epilepsy, insomnia and as a mild sedative. In this work, the free radical scavenging capacity of a methanol extract of BM and the effect on DNA cleavage induced by H2O2 UV-photolysis was investigated. In addition, we examined whether this plant extract is capable of reducing the hydrogen peroxide-induced cytotoxicity and DNA damage in human non-immortalized fibroblasts. It showed a dose-dependent free radical scavenging capacity and a protective effect on DNA cleavage. These results were confirmed by a significant protective effect on H2O2-induced cytoxicity and DNA damage in human non-immortalized fibroblasts. The antioxidant capacity of BM may explain, at least in part, the reported antistress, immunomodulatory, cognition-facilitating, antiinflammatory and antiaging effects produced by it in experimental animals and in clinical situations and may justify further investigation of its other beneficial properties. Moreover, this experimental evidence suggests that because of its antioxidant activity, this Ayurvedic drug may be useful in the treatment of human pathologies in which free radical production plays a key role.
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Affiliation(s)
- Alessandra Russo
- Department of Biochemistry, Medical Chemistry and Molecular Biology, University of Catania, V.le A. Doria 6, 95125, Catania, Italy.
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Russo A, Borrelli F, Campisi A, Acquaviva R, Raciti G, Vanella A. Nitric oxide-related toxicity in cultured astrocytes: effect of Bacopa monniera. Life Sci 2003; 73:1517-26. [PMID: 12865091 DOI: 10.1016/s0024-3205(03)00476-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
There is growing evidence that high concentrations of nitric oxide (NO), generated by activated astrocytes, might be involved in a variety of neurodegenerative diseases, such as Alzheimer's disease, ischemia and epilepsy. It has recently been suggested that glial cells may produce NO under superoxide radical stimulation by enzyme-independent mechanism. This suggests that also natural antioxidants may have therapeutical relevance in neurodegenerative diseases. Studies of Bhattacharya et al. have evidenced that Bacopa monniera (BM) (family Scrophulariaceae), an Ayurvedic medicinal plant clinically used for memory enhancing, epilepsy, insomnia and as a mild sedative, is able to reduce the memory-dysfunction in rat models of Alzheimer's disease, but the molecular mechanisms of this action are yet to be determined. In the present study, we examined the effect of a methanolic extract of BM on toxicity induced by the nitric oxide donor, S-nitroso-N-acetyl-penicillamine (SNAP), in culture of purified rat astrocytes. Our results indicate that, after 18 h of treatment, SNAP induced an increase in the production of reactive species, but did not induce the rupture of cellular membrane. Conversely, this NO donor induced a fragmentation of genomic DNA compared to control astrocytes. The extract of BM inhibited the formation of reactive species and DNA damage in a dose dependent manner. This data supports the traditional use of BM and indicates that this medicinal plant has a therapeutic potential in treatment or prevention of neurological diseases.
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Affiliation(s)
- Alessandra Russo
- Department of Biological Chemistry, Medical Chemistry and Molecular Biology, University of Catania, v.le A. Doria 6, 95125 Catania, Italy.
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Grasso S, Scifo C, Cardile V, Gulino R, Renis M. Adaptive responses to the stress induced by hyperthermia or hydrogen peroxide in human fibroblasts. Exp Biol Med (Maywood) 2003; 228:491-8. [PMID: 12709575 DOI: 10.1177/15353702-0322805-12] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Perturbation of oxidant/antioxidant cellular balance, induced by cellular metabolism and by exogenous sources, causes deleterious effects to proteins, lipids, and nucleic acids, leading to a condition named "oxidative stress" that is involved in several diseases, such as cancer, ischemia-reperfusion injury, and neurodegenerative disorders. Among the exogenous agents, both H(2)O(2) and hyperthermia have been implicated in oxidative stress promotion linked with the activation of apoptotic or necrotic mechanisms of cell death. The goal of this work was to better understand the involvement of some stress-related proteins in adaptive responses mounted by human fibroblasts versus the oxidative stress differently induced by 42 degrees C hyperthermia or H(2)O(2.) The research was developed, switching off inducible nitric oxide synthase (iNOS) expression through antisense oligonucleotide transfection by studying the possible coregulation in the expression of HSP32 (also named HO-1), HSP70, and iNOS and their involvement in the induction of DNA damage. Several biochemical parameters, such as cell viability (MTT assay), cell membrane integrity (lactate dehydrogenase release), reactive oxygen species formation, glutathione levels, immunocytochemistry analysis of iNOS, HSP70, and HO-1 levels, genomic DNA fragmentation (HALO/COMET assay), and transmembrane mitochondrial potential (deltaPsi) were examined. Cells were collected immediately at the end of the stress-inducing treatment. The results, confirming the pleiotropic function of i-NOS, indicate that: (i). HO-1/HSP32, HSP70, and iNOS are finely tuned in their expression to contribute all together, in human fibroblasts, in ameliorating the resistance to oxidative stress damage; (ii). ROS exposure, at least in hyperthermia, in human fibroblasts contributes to growth arrest more than to apoptosis activation; and (iii). mitochondrial dysfunction, in presence of iNOS inhibition seems to be clearly involved in apoptotic cell death of human fibroblasts after H(2)O(2) treatment, but not after hyperthermia.
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Affiliation(s)
- S Grasso
- Department of Biological Chemistry, Catania 95125, Italy
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41
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Russo A, Palumbo M, Aliano C, Lempereur L, Scoto G, Renis M. Red wine micronutrients as protective agents in Alzheimer-like induced insult. Life Sci 2003; 72:2369-79. [PMID: 12639702 DOI: 10.1016/s0024-3205(03)00123-1] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Plant extract micronutrients are commonly added to diets for health and prevention of degenerative disease. However, there are barriers to the introduction of these products as antioxidant therapies in counteracting chronic human diseases, probably because the molecular bases of their therapeutic potential are poorly clarified. The present study was designed to evaluate the possible protective effect of combined micronutrients present in black grape skin on toxicity induced by 25-35 beta-amyloid peptid or by serum of Alzheimer's disease patients, in human umbilical vein endothelial cells (HUVECs). The hypothesis was tested by examining the results of lactic dehydrogenase (LDH) release to estimate cytoplasmic membrane breakdown; activity of mitochondrial complexes, reactive oxygen species (ROS) production and malonyl dialdehyde (MDA) levels as markers of oxidative stress induction and COMET assay to evaluate DNA fragmentation. The results demonstrate that black grape skin extract reduces the ROS production, protects the cellular membrane from oxidative damage, and consequently prevents DNA fragmentation. The experimental results suggest that this natural compound may be used to ameliorate the progression of pathology in AD disease therapy.
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Affiliation(s)
- A Russo
- Department of Biological Chemistry, Medical Chemistry and Molecular Biology, University of Catania, v.le A. Doria 6, 95125, Catania, Italy
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Wang S, Jia Z, Roder J, Murphy TH. AMPA receptor-mediated miniature synaptic calcium transients in GluR2 null mice. J Neurophysiol 2002; 88:29-40. [PMID: 12091530 DOI: 10.1152/jn.2002.88.1.29] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
AMPA-type glutamate receptors are normally Ca(2+) impermeable due to the expression of the GluR2 receptor subunit. By using GluR2 null mice we were able to detect miniature synaptic Ca(2+) transients (MSCTs) associated with AMPA-type receptor-mediated miniature synaptic currents at single synapses in primary cortical cultures. MSCTs and associated Ca(2+) transients were monitored under conditions that isolated responses mediated by AMPA or N-methyl-D-aspartate (NMDA) receptors. As expected, addition of the antagonist 6-cyano-7-nitroquinoxalene-2,3-dione (CNQX, 3 microM) blocked the AMPA receptor-mediated MSCTs. Voltage-gated Ca(2+) channels did not contribute to AMPA MSCTs because CdCl(2) (0.1-0.2 mM) did not significantly alter the frequency or the amplitude of the MSCTs. The amplitude of AMPA MSCTs appeared to be regulated independently from event frequency since the two measures were not correlated (R = 0.023). Synapses were identified that only expressed MSCTs attributed to either NMDA or AMPA receptors. At synapses with only NMDA responses, MSCT amplitude was significantly lower (by 40%) than synapses expressing both NMDA and AMPA responses. At synapses that showed MSCTs mediated by both AMPA and NMDA receptors, the amplitude of the transients in each condition was positively correlated (R = 0.94). Our results suggest that when AMPA and NMDA receptors are co-expressed at synapses, mechanisms exist to ensure proportional scaling of each receptor type that are distinct from the presynaptic factors controlling the frequency of miniature release.
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Affiliation(s)
- Sabrina Wang
- Kinsmen Laboratory, Department of Psychiatry, University of British Columbia, Vancouver, British Columbia V6T 1Z3
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Esquenazi S, Monnerie H, Kaplan P, Le Roux P. BMP-7 and excess glutamate: opposing effects on dendrite growth from cerebral cortical neurons in vitro. Exp Neurol 2002; 176:41-54. [PMID: 12093081 DOI: 10.1006/exnr.2002.7906] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glutamate is an important regulator of dendrite development. During cerebral ischemia, however, there is massive release of glutamate reaching millimolar concentrations in the extracellular space. An early consequence of this excess glutamate is reduced dendrite growth. Bone morphogenetic protein-7 (BMP-7) a member of the transforming growth factor-beta (TGF-beta) superfamily has been demonstrated to enhance dendrite output from cerebral cortical and hippocampal neurons in vitro. However, it is not known whether BMP-7can prevent the reduced dendrite growth associated with excess glutamate or enhance dendrite growth after glutamate exposure. Therefore we quantified axon and primary, secondary, and total dendrite growth from embryonic mouse cortical neurons (E18) grown at low density in vitro in a chemically defined medium and exposed to glutamate (1 or 2 mM) for 48 h. Morphology and double immunolabeling (MAP2, NF-H) were used to identify cortical dendrites and axons after 3 DIV. In these short-term cultures, glutamate did not influence neuron survival. The addition of glutamate to cortical neurons, however, significantly attenuated dendrite output. This effect was mimicked by the addition of NMDA but not AMPA agonists and inhibited by the specific NMDA receptor antagonist MK-801. The reduction in dendrite growth mediated by excess glutamate was ameliorated by the administration of 30 or 100 ng/ml of BMP-7. In addition, when administered in a delayed fashion between 1 and 24 h after the initial glutamate exposure, BMP-7 was able to enhance dendrite growth, including primary dendrite number, primary dendrite length, and secondary dendritic branching. These findings demonstrate that BMP-7 can ameliorate reduced dendrite growth from cerebral cortical neurons associated with excess glutamate in vitro and are important because they may help explain why BMP-7 administration is associated with enhanced functional recovery in models of cerebral ischemia.
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Affiliation(s)
- Susana Esquenazi
- Department of Neurosurgery, New York University, New York, New York, USA
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Galvano F, Campisi A, Russo A, Galvano G, Palumbo M, Renis M, Barcellona ML, Perez-Polo JR, Vanella A. DNA damage in astrocytes exposed to fumonisin B1. Neurochem Res 2002; 27:345-51. [PMID: 11958538 DOI: 10.1023/a:1014971515377] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Fumonisins are a group of toxic metabolites mainly produced by Fusarium moniliforme and Fusarium proliferatum, fungi that commonly occur on corn throughout the world. Fumonisin B1 (FB1), structurally resembling sphingoid bases, is an inhibitor of ceramide synthase, a key enzyme involved in de novo sphingolipid biosynthesis and in the reacylation of free sphingoid bases derived from sphingolipid turnover. This inhibitory effect leads to accumulation of free sphinganine (SA) and sphingosine (SO), inducing cell death. However, little is known on the down stream effectors activated by these sphingolipids in the cell death signaling pathway. We exposed rat astrocytes to FB1 with the aim of evaluating the involvement of oxygen free radicals and of some other biochemical pathways such as caspase-3 activity and DNA damage. Our results indicate that FB1 treatment (48, 72 h and 6 days in vitro, DIV, and 10, 50, 100 microM) does not affect cell viability. Conversely, after 72 h of treatment, FB1 (50 and 100 microM) induced DNA damage and an enhancement of caspase-3 activity compared to controls. In addition, FB1 increased the expression of HSP70 at 10 and 50 microM at 48, 72 h, and 6 DIV of treatment. We conclude that DNA damage of apoptotic type in rat astrocytes is caused by FB1 and that the genotoxic potential of FB1 has probably been underestimated and should be reconsidered.
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Affiliation(s)
- F Galvano
- Department of Agro-forestry, Environmental Science and Technology, University of Reggio Calabria, Italy
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45
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Palumbo M, Russo A, Cardile V, Renis M, Paolino D, Puglisi G, Fresta M. Improved antioxidant effect of idebenone-loaded polyethyl-2-cyanoacrylate nanocapsules tested on human fibroblasts. Pharm Res 2002; 19:71-8. [PMID: 11837703 DOI: 10.1023/a:1013659516878] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
PURPOSE The protective antioxidant role of idebenone both as free drug and drug-loaded Tween 80-coated polyethyl-2-cyanoacrylate (PECA) nanocapsules is reported. The relationship between oxidative damage and apoptotic or nonapoptotic cell death is evaluated in vitro. METHODS Idebenone-loaded nanocapsules were prepared with the interfacial polymerization method in the presence of Tween 80. Human nonimmortalized fibroblasts. under different stress conditions, either 0.5 mM diethylmaleate (DEM) for 60 min or 0.1 mM H2O2 for 30 min, were used as the experimental in vitro model. The production of reactive oxygen species, the cell viability, and the nuclear DNA damage were evaluated. The presence of apoptotic damage was evaluated both by the determination of caspase-3-like protein activity and by Promega's fluorescent apoptotic detection system. RESULTS DEM and H2O2 affected the cultured cells in different ways. DEM induced a moderate cellular insult, which was efficaciously antagonized by idebenone-loaded PECA nanocapsules. H2O2 elicited severe damage to nuclear DNA, which was reduced by idebenoneloaded PECA nanocapsules. The free drug was less effective than idebenone-loaded nanocapsules. CONCLUSIONS The findings reported here demonstrate that an improved antioxidant effect was obtained with a low idebenone concentration (0.5 microM) when the drug was entrapped within Tween 80-coated PECA nanocapsules.
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Galvano F, Russo A, Cardile V, Galvano G, Vanella A, Renis M. DNA damage in human fibroblasts exposed to fumonisin B(1). Food Chem Toxicol 2002; 40:25-31. [PMID: 11731033 DOI: 10.1016/s0278-6915(01)00083-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Fumonisins are mycotoxins produced by several Fusarium species (Fusarium verticilloides and F. proliferatum) that infest corn and other cereals. Fumonisin B(1) (FB(1)), structurally resembling sphingoid bases, is an inhibitor of ceramide synthetase, a key enzyme involved in de novo sphingolipid biosynthesis and in the reacylation of free sphingoid bases derived from sphingolipid turnover. This inhibitory effect leads to accumulation of free sphinganine and sphingosine and subsequent induction of cell death. However, the downstream effectors activated by these sphingolipids in the cell death-signalling pathway are little known. The aim of this study was to evaluate, in FB(1)-exposed human fibroblasts, the involvement of oxygen free radicals and of some other biochemical pathways, caspase-3 activity, poly(ADP-ribose)polymerase (PARP) cleavage and DNA damage evaluated by comet assay. Our results indicate that FB(1) treatment (48, 72 h and 10, 50, 100 microM) does not affect cellular viability. Conversely, after 72 h of treatment, FB(1) (50 and 100 microM) induced DNA damage, an enhancement of caspase-3-activity and cleavage of PARP compared to controls. In addition, FB(1) increased the expression of HSP70 in a concentration and time-dependent manner. Our results indicate that DNA damage of apoptotic type in human fibroblasts is caused by exposure to FB(1) at high concentrations and for a prolonged time and that the genotoxic potential of FB(1) has probably been underestimated and should be reconsidered.
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Affiliation(s)
- F Galvano
- Department of Agro-forestry, Environmental Science and Technology, University of Reggio Calabria, P.zza S. Francesco 7, Reggio Calabria, Italy.
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Bellissimo MI, Amado D, Abdalla DS, Ferreira EC, Cavalheiro EA, Naffah-Mazzacoratti MG. Superoxide dismutase, glutathione peroxidase activities and the hydroperoxide concentration are modified in the hippocampus of epileptic rats. Epilepsy Res 2001; 46:121-8. [PMID: 11463513 DOI: 10.1016/s0920-1211(01)00269-8] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The relationship between free radical and scavenger enzymes has been found in the epileptic phenomena and reactive oxygen species have been implicated in seizure-induced neurodegeneration. Using the epilepsy model obtained by systemic administration of pilocarpine (PILO) in rats, we investigated the superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities as well as the hydroperoxide (HPx) concentration in the hippocampus of rats during status epilepticus (SE), silent and chronic periods. The enzyme activities as well as the HPx concentration were measured using spectrophotometric methods and the results compared to values obtained from saline-treated animals. The SOD activity decreased after long-lasting SE period and during the chronic phase. In addition, HPx levels increased in same periods whereas the GPx activity increased only in the hippocampus of animals submitted to 1 h of SE. Animals presenting partial seizures, those submitted to 5 h of SE and animals from the silent period (seizure free) showed normal levels of SOD, GPx and HPx. These results show a direct evidence of lipid peroxidation during seizure activity that could be responsible for neuronal damage in the hippocampus of rats, during the establishment of PILO model of epilepsy.
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Affiliation(s)
- M I Bellissimo
- Disciplinas de Neurologia Experimental, Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), Rua Botucatu 862, 04023-900 Sao Paulo, Brazil
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Cardile V, Pavone A, Renis M, Maci T, Perciavalle V. Effects of Gabapentin and Topiramate in primary rat astrocyte cultures. Neuroreport 2001; 12:1705-8. [PMID: 11409743 DOI: 10.1097/00001756-200106130-00037] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We studied in vitro the effects of anticonvulsant drugs Gabapentin and Topiramate on the production of reactive oxygen species and nitric oxide (NO), the activity of glutamine synthetase (GS), and cell viability in primary cultures of rat cortical astrocytes which are intimately involved in the normal functioning of neurons. We investigated the effects of these drugs at concentrations within the therapeutic range (1, 10 and 50 microg/ml). We observed that, in cultured astrocytes, Gabapentin induced a weak increase in the biosynthesis of NO, a mild decrease in GS activity and cell viability, and minor induction of a stress condition. Topiramate was observed to induce even greater stressor effects on these cells.
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Affiliation(s)
- V Cardile
- Department of Physiological Sciences, University of Catania, Italy
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Tan S, Somia N, Maher P, Schubert D. Regulation of antioxidant metabolism by translation initiation factor 2alpha. J Cell Biol 2001; 152:997-1006. [PMID: 11238455 PMCID: PMC2198799 DOI: 10.1083/jcb.152.5.997] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Oxidative stress and highly specific decreases in glutathione (GSH) are associated with nerve cell death in Parkinson's disease. Using an experimental nerve cell model for oxidative stress and an expression cloning strategy, a gene involved in oxidative stress-induced programmed cell death was identified which both mediates the cell death program and regulates GSH levels. Two stress-resistant clones were isolated which contain antisense gene fragments of the translation initiation factor (eIF)2alpha and express a low amount of eIF2alpha. Sensitivity is restored when the clones are transfected with full-length eIF2alpha; transfection of wild-type cells with the truncated eIF2alpha gene confers resistance. The phosphorylation of eIF2alpha also results in resistance to oxidative stress. In wild-type cells, oxidative stress results in rapid GSH depletion, a large increase in peroxide levels, and an influx of Ca(2+). In contrast, the resistant clones maintain high GSH levels and show no elevation in peroxides or Ca(2+) when stressed, and the GSH synthetic enzyme gamma-glutamyl cysteine synthetase (gammaGCS) is elevated. The change in gammaGCS is regulated by a translational mechanism. Therefore, eIF2alpha is a critical regulatory factor in the response of nerve cells to oxidative stress and in the control of the major intracellular antioxidant, GSH, and may play a central role in the many neurodegenerative diseases associated with oxidative stress.
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Affiliation(s)
- S Tan
- Cellular Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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Russo A, Izzo AA, Cardile V, Borrelli F, Vanella A. Indian medicinal plants as antiradicals and DNA cleavage protectors. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2001; 8:125-132. [PMID: 11315755 DOI: 10.1078/0944-7113-00021] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Celastrus paniculatus L. (Celastraceae) (CP), Picrorhiza kurroa L. (Scrophulariaceae) (PK) and Withania somnifera L. (Solanaceae) (WS) are Indian medicinal plants having a remarkable reputation, as a factor of health care, among the indigenous medical practitioners. The plants exhibit varying degrees of therapeutic value some of which useful in the treatment of cognitive dysfunction, epilepsy, insomnia, rheumatism, gout, dyspepsia. In this work, we have investigated the free radical scavenging capacity of methanolic extracts from CP, PK, WS and the effect on DNA cleavage induced by H2O2 UV-photholysis. In addition, we investigated whether these plant extracts are capable of reducing the hydrogen peroxide-induced cytotoxicity and DNA damage in human non-immortalized fibroblasts. These extracts showed a dose-dependent free radical scavenging capacity and a protective effect on DNA cleavage; methanolic extracts from PK was more active than extracts from CP and WS. These results were confirmed by a significant protective effect on H2O2-induced cytoxicity and DNA damage in human non-immortalized fibroblasts. These antioxidant effects of active principle of CP, PK and WS may explain, at least in part, the reported anti-stress, immunomodulatory, cognition-facilitating, anti-inflammatory and antiaging effects produced by them in experimental animal and in clinical situations and may justify the further investigation of their other beneficial biological properties.
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Affiliation(s)
- A Russo
- Department of Biochemistry, Medical Chemistry and Molecular Biology, University of Catania, Italy.
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