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Novorolsky RJ, Kasheke GDS, Hakim A, Foldvari M, Dorighello GG, Sekler I, Vuligonda V, Sanders ME, Renden RB, Wilson JJ, Robertson GS. Preserving and enhancing mitochondrial function after stroke to protect and repair the neurovascular unit: novel opportunities for nanoparticle-based drug delivery. Front Cell Neurosci 2023; 17:1226630. [PMID: 37484823 PMCID: PMC10360135 DOI: 10.3389/fncel.2023.1226630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 06/22/2023] [Indexed: 07/25/2023] Open
Abstract
The neurovascular unit (NVU) is composed of vascular cells, glia, and neurons that form the basic component of the blood brain barrier. This intricate structure rapidly adjusts cerebral blood flow to match the metabolic needs of brain activity. However, the NVU is exquisitely sensitive to damage and displays limited repair after a stroke. To effectively treat stroke, it is therefore considered crucial to both protect and repair the NVU. Mitochondrial calcium (Ca2+) uptake supports NVU function by buffering Ca2+ and stimulating energy production. However, excessive mitochondrial Ca2+ uptake causes toxic mitochondrial Ca2+ overloading that triggers numerous cell death pathways which destroy the NVU. Mitochondrial damage is one of the earliest pathological events in stroke. Drugs that preserve mitochondrial integrity and function should therefore confer profound NVU protection by blocking the initiation of numerous injury events. We have shown that mitochondrial Ca2+ uptake and efflux in the brain are mediated by the mitochondrial Ca2+ uniporter complex (MCUcx) and sodium/Ca2+/lithium exchanger (NCLX), respectively. Moreover, our recent pharmacological studies have demonstrated that MCUcx inhibition and NCLX activation suppress ischemic and excitotoxic neuronal cell death by blocking mitochondrial Ca2+ overloading. These findings suggest that combining MCUcx inhibition with NCLX activation should markedly protect the NVU. In terms of promoting NVU repair, nuclear hormone receptor activation is a promising approach. Retinoid X receptor (RXR) and thyroid hormone receptor (TR) agonists activate complementary transcriptional programs that stimulate mitochondrial biogenesis, suppress inflammation, and enhance the production of new vascular cells, glia, and neurons. RXR and TR agonism should thus further improve the clinical benefits of MCUcx inhibition and NCLX activation by increasing NVU repair. However, drugs that either inhibit the MCUcx, or stimulate the NCLX, or activate the RXR or TR, suffer from adverse effects caused by undesired actions on healthy tissues. To overcome this problem, we describe the use of nanoparticle drug formulations that preferentially target metabolically compromised and damaged NVUs after an ischemic or hemorrhagic stroke. These nanoparticle-based approaches have the potential to improve clinical safety and efficacy by maximizing drug delivery to diseased NVUs and minimizing drug exposure in healthy brain and peripheral tissues.
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Affiliation(s)
- Robyn J. Novorolsky
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Gracious D. S. Kasheke
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Antoine Hakim
- School of Pharmacy, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
| | - Marianna Foldvari
- School of Pharmacy, Faculty of Science, University of Waterloo, Waterloo, ON, Canada
| | - Gabriel G. Dorighello
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
| | - Israel Sekler
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben Gurion University, Beersheva, Israel
| | | | | | - Robert B. Renden
- Department of Physiology and Cell Biology, School of Medicine, University of Nevada, Reno, NV, United States
| | - Justin J. Wilson
- Department of Chemistry and Chemical Biology, College of Arts and Sciences, Cornell University, Ithaca, NY, United States
| | - George S. Robertson
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
- Department of Psychiatry, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada
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2
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Woods JJ, Novorolsky RJ, Bigham NP, Robertson GS, Wilson JJ. Dinuclear nitrido-bridged osmium complexes inhibit the mitochondrial calcium uniporter and protect cortical neurons against lethal oxygen-glucose deprivation. RSC Chem Biol 2023; 4:84-93. [PMID: 36685255 PMCID: PMC9811523 DOI: 10.1039/d2cb00189f] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 11/05/2022] [Indexed: 11/16/2022] Open
Abstract
Dysregulation of mitochondrial calcium uptake mediated by the mitochondrial calcium uniporter (MCU) is implicated in several pathophysiological conditions. Dinuclear ruthenium complexes are effective inhibitors of the MCU and have been leveraged as both tools to study mitochondrial calcium dynamics and potential therapeutic agents. In this study, we report the synthesis and characterization of Os245 ([Os2(μ-N)(NH3)8Cl2]3+) which is the osmium-containing analogue of our previously reported ruthenium-based inhibitor Ru265. This complex and its aqua-capped analogue Os245' ([Os2(μ-N)(NH3)8(OH2)2]5+) are both effective inhibitors of the MCU in permeabilized and intact cells. In comparison to the ruthenium-based inhibitor Ru265 (k obs = 4.92 × 10-3 s-1), the axial ligand exchange kinetics of Os245 are two orders of magnitude slower (k obs = 1.63 × 10-5 s-1) at 37 °C. The MCU-inhibitory properties of Os245 and Os245' are different (Os245 IC50 for MCU inhibition = 103 nM; Os245' IC50 for MCU inhibition = 2.3 nM), indicating that the axial ligands play an important role in their interactions with this channel. We further show that inhibition of the MCU by these complexes protects primary cortical neurons against lethal oxygen-glucose deprivation. When administered in vivo to mice (10 mg kg-1), Os245 and Os245' induce seizure-like behaviors in a manner similar to the ruthenium-based inhibitors. However, the onset of these seizures is delayed, a possible consequence of the slower ligand substitution kinetics for these osmium complexes. These findings support previous studies that demonstrate inhibition of the MCU is a promising therapeutic strategy for the treatment of ischemic stroke, but also highlight the need for improved drug delivery strategies to mitigate the pro-convulsant effects of this class of complexes before they can be implemented as therapeutic agents. Furthermore, the slower ligand substitution kinetics of the osmium analogues may afford new strategies for the development and modification of this class of MCU inhibitors.
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Affiliation(s)
- Joshua J. Woods
- Department of Chemistry and Chemical Biology, Cornell UniversityIthacaNY14853USA,Robert F. Smith School for Chemical and Biomolecular Engineering, Cornell UniversityIthacaNY14853USA
| | - Robyn J. Novorolsky
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Life Sciences Research InstituteHalifaxNS B3H 0A8Canada,Brain Repair Centre, Faculty of Medicine, Dalhousie University, Life Sciences Research InstituteHalifaxNS B3H 0A8Canada
| | - Nicholas P. Bigham
- Department of Chemistry and Chemical Biology, Cornell UniversityIthacaNY14853USA
| | - George S. Robertson
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Life Sciences Research InstituteHalifaxNS B3H 0A8Canada,Brain Repair Centre, Faculty of Medicine, Dalhousie University, Life Sciences Research InstituteHalifaxNS B3H 0A8Canada,Department of Psychiatry, Faculty of Medicine, Dalhousie University, Life Sciences Research InstituteHalifaxNS B3H0A8Canada
| | - Justin J. Wilson
- Department of Chemistry and Chemical Biology, Cornell UniversityIthacaNY14853USA
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Kasheke GDS, Holman SP, Robertson GS. Fingolimod attenuates gait deficits in mice subjected to experimental autoimmune encephalomyelitis. J Neuroimmunol 2022; 370:577926. [PMID: 35863299 DOI: 10.1016/j.jneuroim.2022.577926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 05/31/2022] [Accepted: 07/09/2022] [Indexed: 10/17/2022]
Abstract
Fingolimod, used to treat relapsing-remitting multiple sclerosis (RRMS), reduces motor deficits in mice with established experimental autoimmune encephalomyelitis (EAE). To better characterize the therapeutic effects of fingolimod, kinematic gait analysis was employed to precisely measure movements of a hindleg while EAE mice walked on a treadmill. Relative to the vehicle group, oral dosing with fingolimod, beginning after disease onset (1 mg/kg/day), increased hip heights and knee joint movements, and reduced spinal cord demyelination. These findings suggest that fingolimod preserves gait in RRMS patients by protecting motor circuits in the spinal cord.
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Affiliation(s)
- Gracious D S Kasheke
- Department of Pharmacology, Brain Repair Centre, Faculty of Medicine, Life Sciences Research Institute, 2nd floor 1348 Summer Street, P.O. Box 15000, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
| | - Scott P Holman
- Department of Pharmacology, Brain Repair Centre, Faculty of Medicine, Life Sciences Research Institute, 2nd floor 1348 Summer Street, P.O. Box 15000, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - George S Robertson
- Department of Pharmacology, Brain Repair Centre, Faculty of Medicine, Life Sciences Research Institute, 2nd floor 1348 Summer Street, P.O. Box 15000, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Department of Psychiatry, 5909 Veterans' Memorial Lane, 8th floor, Abbie J. Lane Memorial Building, QEII Health Sciences Centre, Halifax, Nova Scotia B3H 2E2, Canada.
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4
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Tavasoli M, Lahire S, Sokolenko S, Novorolsky R, Reid SA, Lefsay A, Otley MOC, Uaesoontrachoon K, Rowsell J, Srinivassane S, Praest M, MacKinnon A, Mammoliti MS, Maloney AA, Moraca M, Pedro Fernandez-Murray J, McKenna M, Sinal CJ, Nagaraju K, Robertson GS, Hoffman EP, McMaster CR. Mechanism of action and therapeutic route for a muscular dystrophy caused by a genetic defect in lipid metabolism. Nat Commun 2022; 13:1559. [PMID: 35322809 PMCID: PMC8943011 DOI: 10.1038/s41467-022-29270-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 02/23/2022] [Indexed: 12/01/2022] Open
Abstract
CHKB encodes one of two mammalian choline kinase enzymes that catalyze the first step in the synthesis of the membrane phospholipid phosphatidylcholine. In humans and mice, inactivation of the CHKB gene (Chkb in mice) causes a recessive rostral-to-caudal muscular dystrophy. Using Chkb knockout mice, we reveal that at no stage of the disease is phosphatidylcholine level significantly altered. We observe that in affected muscle a temporal change in lipid metabolism occurs with an initial inability to utilize fatty acids for energy via mitochondrial β-oxidation resulting in shunting of fatty acids into triacyglycerol as the disease progresses. There is a decrease in peroxisome proliferator-activated receptors and target gene expression specific to Chkb−/− affected muscle. Treatment of Chkb−/− myocytes with peroxisome proliferator-activated receptor agonists enables fatty acids to be used for β-oxidation and prevents triacyglyerol accumulation, while simultaneously increasing expression of the compensatory choline kinase alpha (Chka) isoform, preventing muscle cell injury. Mutations in the CHKB gene cause muscular dystrophy. Here, the authors show that in mouse models of the disease changes in lipid metabolism are associated with decreased PPAR signaling, and show PPAR agonists can rescue expression of injury markers in myocytes in vitro.
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Affiliation(s)
- Mahtab Tavasoli
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Sarah Lahire
- University of Reims Champagne-Ardenne, Reims, France
| | - Stanislav Sokolenko
- Department of Process Engineering & Applied Science, Dalhousie University, Halifax, NS, Canada
| | - Robyn Novorolsky
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Sarah Anne Reid
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Abir Lefsay
- Mass Spectrometry Core Facility, Dalhousie University, Halifax, NS, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | - Kanneboyina Nagaraju
- Agada Biosciences Inc., Halifax, NS, Canada.,School of Pharmacy and Pharmaceutical Sciences, Binghamton University, State University of New York (SUNY), Binghamton, NY, USA
| | - George S Robertson
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada.,Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Eric P Hoffman
- Agada Biosciences Inc., Halifax, NS, Canada.,School of Pharmacy and Pharmaceutical Sciences, Binghamton University, State University of New York (SUNY), Binghamton, NY, USA
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5
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Layton GR, Chung WY, Isherwood J, Fraser RE, Issa E, Robertson GS, Garcea G, Bhardwaj N, Dennison AR. Endoscopic retrograde cholangiopancreatography in the COVID era: considerations for hepatobiliary and pancreatic surgery units. Br J Surg 2021; 108:e290-e291. [PMID: 34000030 DOI: 10.1093/bjs/znab161] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Accepted: 04/14/2021] [Indexed: 01/28/2023]
Affiliation(s)
- G R Layton
- Department of Hepatobiliary and Pancreatic Surgery, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - W Y Chung
- Department of Hepatobiliary and Pancreatic Surgery, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - J Isherwood
- Department of Hepatobiliary and Pancreatic Surgery, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - R E Fraser
- Department of Hepatobiliary and Pancreatic Surgery, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - E Issa
- Department of Hepatobiliary and Pancreatic Surgery, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - G S Robertson
- Department of Hepatobiliary and Pancreatic Surgery, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - G Garcea
- Department of Hepatobiliary and Pancreatic Surgery, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - N Bhardwaj
- Department of Hepatobiliary and Pancreatic Surgery, University Hospitals of Leicester NHS Trust, Leicester, UK
| | - A R Dennison
- Department of Hepatobiliary and Pancreatic Surgery, University Hospitals of Leicester NHS Trust, Leicester, UK
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Deurveilher S, Ko KR, Saumure BSC, Robertson GS, Rusak B, Semba K. Altered circadian activity and sleep/wake rhythms in the stable tubule only polypeptide (STOP) null mouse model of schizophrenia. Sleep 2021; 44:5981350. [PMID: 33186470 DOI: 10.1093/sleep/zsaa237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/14/2020] [Indexed: 12/27/2022] Open
Abstract
Sleep and circadian rhythm disruptions commonly occur in individuals with schizophrenia. Stable tubule only polypeptide (STOP) knockout (KO) mice show behavioral impairments resembling symptoms of schizophrenia. We previously reported that STOP KO mice slept less and had more fragmented sleep and waking than wild-type littermates under a light/dark (LD) cycle. Here, we assessed the circadian phenotype of male STOP KO mice by examining wheel-running activity rhythms and EEG/EMG-defined sleep/wake states under both LD and constant darkness (DD) conditions. Wheel-running activity rhythms in KO and wild-type mice were similarly entrained in LD, and had similar free-running periods in DD. The phase delay shift in response to a light pulse given early in the active phase under DD was preserved in KO mice. KO mice had markedly lower activity levels, lower amplitude activity rhythms, less stable activity onsets, and more fragmented activity than wild-type mice in both lighting conditions. KO mice also spent more time awake and less time in rapid eye movement sleep (REMS) and non-REMS (NREMS) in both LD and DD conditions, with the decrease in NREMS concentrated in the active phase. KO mice also showed altered EEG features and higher amplitude rhythms in wake and NREMS (but not REMS) amounts in both lighting conditions, with a longer free-running period in DD, compared to wild-type mice. These results indicate that the STOP null mutation in mice altered the regulation of sleep/wake physiology and activity rhythm expression, but did not grossly disrupt circadian mechanisms.
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Affiliation(s)
- Samuel Deurveilher
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - Kristin Robin Ko
- School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada
| | - Brock St C Saumure
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - George S Robertson
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.,Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Benjamin Rusak
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.,Department of Psychology & Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - Kazue Semba
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada.,Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.,Department of Psychology & Neuroscience, Dalhousie University, Halifax, NS, Canada
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Hall S, Deurveilher S, Robertson GS, Semba K. Homeostatic state of microglia in a rat model of chronic sleep restriction. Sleep 2021; 43:5849344. [PMID: 32474610 DOI: 10.1093/sleep/zsaa108] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 05/13/2020] [Indexed: 12/29/2022] Open
Abstract
Chronic sleep restriction (CSR) negatively impacts brain functions. Whether microglia, the brain's resident immune cells, play any role is unknown. We studied microglia responses to CSR using a rat model featuring slowly rotating wheels (3 h on/1 h off), which was previously shown to induce both homeostatic and adaptive responses in sleep and attention. Adult male rats were sleep restricted for 27 or 99 h. Control rats were housed in locked wheels. After 27 and/or 99 h of CSR, the number of cells immunoreactive for the microglia marker ionized calcium-binding adaptor molecule-1 (Iba1) and the density of Iba1 immunoreactivity were increased in 4/10 brain regions involved in sleep/wake regulation and cognition, including the prelimbic cortex, central amygdala, perifornical lateral hypothalamic area, and dorsal raphe nucleus. CSR neither induced mitosis in microglia (assessed with bromodeoxyuridine) nor impaired blood-brain barrier permeability (assessed with Evans Blue). Microglia appeared ramified in all treatment groups and, when examined quantitatively in the prelimbic cortex, their morphology was not affected by CSR. After 27 h, but not 99 h, of CSR, mRNA levels of the anti-inflammatory cytokine interleukin-10 were increased in the frontal cortex. Pro-inflammatory cytokine mRNA levels (tumor necrosis factor-α, interleukin-1β, and interleukin-6) were unchanged. Furthermore, cortical microglia were not immunoreactive for several pro- and anti-inflammatory markers tested, but were immunoreactive for the purinergic P2Y12 receptor. These results suggest that microglia respond to CSR while remaining in a physiological state and may contribute to the previously reported homeostatic and adaptive responses to CSR.
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Affiliation(s)
- Shannon Hall
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - Samüel Deurveilher
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - George S Robertson
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada.,Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Kazue Semba
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada.,Department of Psychiatry, Dalhousie University, Halifax, NS, Canada.,Department of Psychology & Neuroscience, Dalhousie University, Halifax, NS, Canada
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Holman SP, Lobo AS, Novorolsky RJ, Nichols M, Fiander MDJ, Konda P, Kennedy BE, Gujar S, Robertson GS. Neuronal mitochondrial calcium uniporter deficiency exacerbates axonal injury and suppresses remyelination in mice subjected to experimental autoimmune encephalomyelitis. Exp Neurol 2020; 333:113430. [PMID: 32745471 DOI: 10.1016/j.expneurol.2020.113430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/05/2020] [Accepted: 07/28/2020] [Indexed: 12/11/2022]
Abstract
High-capacity mitochondrial calcium (Ca2+) uptake by the mitochondrial Ca2+ uniporter (MCU) is strategically positioned to support the survival and remyelination of axons in multiple sclerosis (MS) by undocking mitochondria, buffering Ca2+ and elevating adenosine triphosphate (ATP) synthesis at metabolically stressed sites. Respiratory chain deficits in MS are proposed to metabolically compromise axon survival and remyelination by suppressing MCU activity. In support of this hypothesis, clinical scores, mitochondrial dysfunction, myelin loss, axon damage and inflammation were elevated while remyelination was blocked in neuronal MCU deficient (Thy1-MCU Def) mice relative to Thy1 controls subjected to experimental autoimmune encephalomyelitis (EAE). At the first sign of walking deficits, mitochondria in EAE/Thy1 axons showed signs of activation. By contrast, cytoskeletal damage, fragmented mitochondria and large autophagosomes were seen in EAE/Thy1-MCU Def axons. As EAE severity increased, EAE/Thy1 axons were filled with massively swollen mitochondria with damaged cristae while EAE/Thy1-MCU Def axons were riddled with late autophagosomes. ATP concentrations and mitochondrial gene expression were suppressed while calpain activity, autophagy-related gene mRNA levels and autophagosome marker (LC3) co-localization in Thy1-expressing neurons were elevated in the spinal cords of EAE/Thy1-MCU Def compared to EAE/Thy1 mice. These findings suggest that MCU inhibition contributes to axonal damage that drives MS progression.
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Affiliation(s)
- Scott P Holman
- Department of Pharmacology, Brain Repair Centre, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada; Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada
| | - Aurelio S Lobo
- Department of Pharmacology, Brain Repair Centre, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada; Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada
| | - Robyn J Novorolsky
- Department of Pharmacology, Brain Repair Centre, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada; Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada
| | - Matthew Nichols
- Department of Pharmacology, Brain Repair Centre, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada; Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada
| | - Maximillian D J Fiander
- Department of Pharmacology, Brain Repair Centre, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada; Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada
| | - Prathyusha Konda
- Department of Pathology, Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada
| | - Barry E Kennedy
- Department of Pathology, Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada
| | - Shashi Gujar
- Department of Pathology, Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada
| | - George S Robertson
- Department of Pharmacology, Brain Repair Centre, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada; Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada; Department of Psychiatry, 5909 Veterans' Memorial Lane, 8th Floor, Abbie J. Lane Memorial Building, QEII Health Sciences Centre, Halifax B3H 2E2, Canada.
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Novorolsky RJ, Nichols M, Kim JS, Pavlov EV, J Woods J, Wilson JJ, Robertson GS. The cell-permeable mitochondrial calcium uniporter inhibitor Ru265 preserves cortical neuron respiration after lethal oxygen glucose deprivation and reduces hypoxic/ischemic brain injury. J Cereb Blood Flow Metab 2020; 40:1172-1181. [PMID: 32126877 PMCID: PMC7238378 DOI: 10.1177/0271678x20908523] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 12/18/2019] [Accepted: 01/31/2020] [Indexed: 01/20/2023]
Abstract
The mitochondrial calcium (Ca2+) uniporter (MCU) mediates high-capacity mitochondrial Ca2+ uptake implicated in ischemic/reperfusion cell death. We have recently shown that inducible MCU ablation in Thy1-expressing neurons renders mice resistant to sensorimotor deficits and forebrain neuron loss in a model of hypoxic/ischemic (HI) brain injury. These findings encouraged us to compare the neuroprotective effects of Ru360 and the recently identified cell permeable MCU inhibitor Ru265. Unlike Ru360, Ru265 (2-10 µM) reached intracellular concentrations in cultured cortical neurons that preserved cell viability, blocked the protease activity of Ca2+-dependent calpains and maintained mitochondrial respiration and glycolysis after a lethal period of oxygen-glucose deprivation (OGD). Intraperitoneal (i.p.) injection of adult male C57Bl/6 mice with Ru265 (3 mg/kg) also suppressed HI-induced sensorimotor deficits and brain injury. However, higher doses of Ru265 (10 and 30 mg/kg, i.p.) produced dose-dependent increases in the frequency and duration of seizure-like behaviours. Ru265 is proposed to promote convulsions by reducing Ca2+ buffering and energy production in highly energetic interneurons that suppress brain seizure activity. These findings support the therapeutic potential of MCU inhibition in the treatment of ischemic stroke but also indicate that such clinical translation will require drug delivery strategies which mitigate the pro-convulsant effects of Ru265.
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Affiliation(s)
- Robyn J Novorolsky
- Department of Pharmacology, Faculty of Medicine,
Dalhousie University, Life Sciences Research Institute, Halifax,
Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie
University, Life Sciences Research Institute, Halifax, Canada
| | - Matthew Nichols
- Department of Pharmacology, Faculty of Medicine,
Dalhousie University, Life Sciences Research Institute, Halifax,
Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie
University, Life Sciences Research Institute, Halifax, Canada
| | - Jong S Kim
- Department of Community Health and Epidemiology,
Faculty of Medicine, Centre for Clinical Research, Dalhousie
University, Halifax, Nova Scotia, Canada
- Department of Microbiology, Faculty of Medicine,
Centre for Clinical Research, Dalhousie University, Nova Scotia,
Canada
| | - Evgeny V Pavlov
- Department of Basic Sciences, College of Dentistry,
New York University, NY, USA
| | - Joshua J Woods
- Department of Chemistry and Chemical Biology, Cornell
University, Baker Laboratory, Ithaca, NY, USA
| | - Justin J Wilson
- Department of Chemistry and Chemical Biology, Cornell
University, Baker Laboratory, Ithaca, NY, USA
| | - George S Robertson
- Department of Pharmacology, Faculty of Medicine,
Dalhousie University, Life Sciences Research Institute, Halifax,
Canada
- Brain Repair Centre, Faculty of Medicine, Dalhousie
University, Life Sciences Research Institute, Halifax, Canada
- Department of Psychiatry, Faculty of Medicine,
Dalhousie University, Life Sciences Research Institute, Halifax,
Canada
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Lamport AC, Chedrawe M, Nichols M, Robertson GS. Experimental autoimmune encephalomyelitis accelerates remyelination after lysophosphatidylcholine-induced demyelination in the corpus callosum. J Neuroimmunol 2019; 334:576995. [PMID: 31228686 DOI: 10.1016/j.jneuroim.2019.576995] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 06/13/2019] [Accepted: 06/13/2019] [Indexed: 01/18/2023]
Abstract
Experimental autoimmune encephalomyelitis (EAE) and lysophosphatidylcholine (LPC)-induced demyelination were combined to study remyelination in a pro-inflammatory context. Two groups of female C57BL/6 mice were subjected either to EAE (EAE mice) or injected with just complete Freund's adjuvant (CFA) and pertussis toxin (PTX) followed by bilateral LPC and phosphate buffered saline injections in the corpus callosum on day 7 (CFA controls). Relative to CFA controls, EAE accelerated remyelination and increased innate immune cell activation, lymphocyte infiltration and cytokine gene expression in the LPC lesions. However, compared to CFA mice, remyelination was reduced (day 14) suggesting this aggressive immune response also compromised myelin repair in EAE mice.
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Affiliation(s)
- Anna-Claire Lamport
- Department of Pharmacology, Brain Repair Centre, Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada
| | - Matthew Chedrawe
- Department of Pharmacology, Brain Repair Centre, Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada
| | - Matthew Nichols
- Department of Pharmacology, Brain Repair Centre, Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada
| | - George S Robertson
- Department of Pharmacology, Brain Repair Centre, Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada; Department of Psychiatry, Brain Repair Centre, Faculty of Medicine, Dalhousie University, 1348 Summer Street, Life Sciences Research Institute, North Tower, Halifax B3H 4R2, Canada.
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Ploughman M, Eskes GA, Kelly LP, Kirkland MC, Devasahayam AJ, Wallack EM, Abraha B, Hasan SMM, Downer MB, Keeler L, Wilson G, Skene E, Sharma I, Chaves AR, Curtis ME, Bedford E, Robertson GS, Moore CS, McCarthy J, Mackay-Lyons M. Synergistic Benefits of Combined Aerobic and Cognitive Training on Fluid Intelligence and the Role of IGF-1 in Chronic Stroke. Neurorehabil Neural Repair 2019; 33:199-212. [PMID: 30816066 DOI: 10.1177/1545968319832605] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Paired exercise and cognitive training have the potential to enhance cognition by "priming" the brain and upregulating neurotrophins. METHODS Two-site randomized controlled trial. Fifty-two patients >6 months poststroke with concerns about cognitive impairment trained 50 to 70 minutes, 3× week for 10 weeks with 12-week follow-up. Participants were randomized to 1 of 2 physical interventions: Aerobic (>60% VO2peak using <10% body weight-supported treadmill) or Activity (range of movement and functional tasks). Exercise was paired with 1 of 2 cognitive interventions (computerized dual working memory training [COG] or control computer games [Games]). The primary outcome for the 4 groups (Aerobic + COG, Aerobic + Games, Activity + COG, and Activity + Games) was fluid intelligence measured using Raven's Progressive Matrices Test administered at baseline, posttraining, and 3-month follow-up. Serum neurotrophins collected at one site (N = 30) included brain-derived neurotrophic factor (BDNF) at rest (BDNFresting) and after a graded exercise test (BDNFresponse) and insulin-like growth factor-1 at the same timepoints (IGF-1rest, IGF-1response). RESULTS At follow-up, fluid intelligence scores significantly improved compared to baseline in the Aerobic + COG and Activity + COG groups; however, only the Aerobic + COG group was significantly different (+47.8%) from control (Activity + Games -8.5%). Greater IGF-1response at baseline predicted 40% of the variance in cognitive improvement. There was no effect of the interventions on BDNFresting or BDNFresponse; nor was BDNF predictive of the outcome. CONCLUSIONS Aerobic exercise combined with cognitive training improved fluid intelligence by almost 50% in patients >6 months poststroke. Participants with more robust improvements in cognition were able to upregulate higher levels of serum IGF-1 suggesting that this neurotrophin may be involved in behaviorally induced plasticity.
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Affiliation(s)
- Michelle Ploughman
- 1 Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Gail A Eskes
- 2 Dalhousie University, Halifax, Nova Scotia, Canada NL, Canada
| | - Liam P Kelly
- 1 Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Megan C Kirkland
- 1 Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | | | - Elizabeth M Wallack
- 1 Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Beraki Abraha
- 1 Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - S M Mahmudul Hasan
- 1 Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Matthew B Downer
- 1 Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Laura Keeler
- 2 Dalhousie University, Halifax, Nova Scotia, Canada NL, Canada
| | - Graham Wilson
- 2 Dalhousie University, Halifax, Nova Scotia, Canada NL, Canada
| | - Elaine Skene
- 2 Dalhousie University, Halifax, Nova Scotia, Canada NL, Canada
| | - Ishika Sharma
- 2 Dalhousie University, Halifax, Nova Scotia, Canada NL, Canada
| | - Arthur R Chaves
- 1 Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Marie E Curtis
- 1 Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Emily Bedford
- 2 Dalhousie University, Halifax, Nova Scotia, Canada NL, Canada
| | | | - Craig S Moore
- 1 Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
| | - Jason McCarthy
- 1 Memorial University of Newfoundland, St. John's, Newfoundland and Labrador, Canada
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12
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Chedrawe MAJ, Holman SP, Lamport AC, Akay T, Robertson GS. Pioglitazone is superior to quetiapine, clozapine and tamoxifen at alleviating experimental autoimmune encephalomyelitis in mice. J Neuroimmunol 2018; 321:72-82. [PMID: 29957391 DOI: 10.1016/j.jneuroim.2018.06.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 05/23/2018] [Accepted: 06/04/2018] [Indexed: 12/17/2022]
Abstract
Recent evidence suggests that clozapine and quetiapine (atypical antipsychotics), tamoxifen (selective-estrogen receptor modulator) and pioglitazone (PPARγ agonist) may improve functional recovery in multiple sclerosis (MS). We have compared the effectiveness of oral administration of these drugs, beginning at peak disease, at reducing ascending paralysis, motor deficits and demyelination in mice subjected to experimental autoimmune encephalomyelitis (EAE). Mice were immunized with an immunogenic peptide corresponding to amino acids 35-55 of the myelin oligodendrocyte glycoprotein (MOG35-55) in complete Freund's adjuvant and injected with pertussis toxin to induce EAE. Unlike clozapine, quetiapine and tamoxifen, administration of pioglitazone beginning at peak disease decreased both clinical scores and lumbar white matter loss in EAE mice. Using kinematic gait analysis, we found that pioglitazone also maintained normal movement of the hip, knee and ankle joints for at least 44 days after MOG35-55 immunization. This long-lasting preservation of hindleg joint movements was accompanied by reduced white matter loss, microglial and macrophage activation and the expression of pro-inflammatory genes in the lumbar spinal cords of EAE mice. These results support clinical findings that suggest pioglitazone may reduce the progressive loss of motor function in MS by decreasing inflammation and myelin damage.
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Affiliation(s)
- Matthew A J Chedrawe
- Department of Pharmacology, Brain Repair Centre, Faculty of Medicine, 2nd floor, Life Sciences Research Institute, 1348 Summer Street, P.O. Box 15000, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
| | - Scott P Holman
- Department of Pharmacology, Brain Repair Centre, Faculty of Medicine, 2nd floor, Life Sciences Research Institute, 1348 Summer Street, P.O. Box 15000, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Anna-Claire Lamport
- Department of Pharmacology, Brain Repair Centre, Faculty of Medicine, 2nd floor, Life Sciences Research Institute, 1348 Summer Street, P.O. Box 15000, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
| | - Turgay Akay
- Department of Medical Neuroscience, Brain Repair Centre, Faculty of Medicine, 3rd floor, Life Sciences Research Institute, 1348 Summer Street, P.O. Box 15000, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
| | - George S Robertson
- Department of Pharmacology, Brain Repair Centre, Faculty of Medicine, 2nd floor, Life Sciences Research Institute, 1348 Summer Street, P.O. Box 15000, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Department of Psychiatry, 5909 Veterans' Memorial Lane, 8th floor, Abbie J. Lane Memorial Building, QEII Health Sciences Centre, Halifax, Nova Scotia B3H 2E2, Canada.
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13
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Nichols M, Pavlov EV, Robertson GS. Tamoxifen-induced knockdown of the mitochondrial calcium uniporter in Thy1-expressing neurons protects mice from hypoxic/ischemic brain injury. Cell Death Dis 2018; 9:606. [PMID: 29789575 PMCID: PMC5964108 DOI: 10.1038/s41419-018-0607-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 03/14/2018] [Accepted: 03/29/2018] [Indexed: 12/24/2022]
Abstract
The mitochondrial calcium uniporter (MCU) mediates high-capacity mitochondrial calcium uptake that stimulates energy production. However, excessive MCU activity can cause ischemic heart injury. To examine if the MCU is also involved in hypoxic/ischemic (HI) brain injury, we have generated conditional MCU knockout mice by tamoxifen (TMX) administration to adult MCU-floxed (MCUfl/fl) mice expressing a construct encoding Thy1-cre/ERT2-eYFP. Relative to TMX/Thy1-cre/ERT2-eYFP controls, HI-induced sensorimotor deficits, forebrain neuron loss and mitochondrial damage were decreased for conditional MCU knockout mice. MCU knockdown by siRNA-induced silencing in cortical neuron cultures also reduced cell death and mitochondrial respiratory deficits following oxygen-glucose deprivation. Furthermore, MCU silencing did not produce metabolic abnormalities in cortical neurons observed previously for global MCU nulls that increased reliance on glycolysis for energy production. Based on these findings, we propose that brain-penetrant MCU inhibitors have strong potential to be well-tolerated and highly-efficacious neuroprotectants for the acute management of ischemic stroke.
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Affiliation(s)
- Matthew Nichols
- Department of Pharmacology, Brain Repair Centre, Faculty of Medicine, 2nd Floor, Life Sciences Research Institute, Dalhousie University, 1348 Summer Street, P.O. Box 15000, Halifax, Nova Scotia, Canada, B3H 4R2
| | - Evgeny V Pavlov
- Department of Basic Sciences, College of Dentistry, New York University, 345 East 24th Street, New York, NY, 10010, USA
| | - George S Robertson
- Department of Pharmacology, Brain Repair Centre, Faculty of Medicine, 2nd Floor, Life Sciences Research Institute, Dalhousie University, 1348 Summer Street, P.O. Box 15000, Halifax, Nova Scotia, Canada, B3H 4R2. .,Department of Psychiatry, QEII Health Sciences Centre, 5909 Veterans' Memorial Lane, 8th floor, Abbie J. Lane Memorial Building, Halifax, NS, B3H 2E2, Canada.
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14
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Fiander MD, Chedrawe MA, Lamport AC, Akay T, Robertson GS. Sagittal Plane Kinematic Gait Analysis in C57BL/6 Mice Subjected to MOG35-55 Induced Experimental Autoimmune Encephalomyelitis. J Vis Exp 2017. [PMID: 29155752 DOI: 10.3791/56032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Kinematic gait analysis in the sagittal plane has frequently been used to characterize motor deficits in multiple sclerosis (MS). We describe the application of these techniques to identify gait deficits in a mouse model of MS, known as experimental autoimmune encephalomyelitis (EAE). Paralysis and motor deficits in mice subjected to EAE are typically assessed using a clinical scoring scale. However, this scale yields only ordinal data that provides little information about the precise nature of the motor deficits. EAE disease severity has also been assessed by rotarod performance, which provides a measure of general motor coordination. By contrast, kinematic gait analysis of the hind limb in the sagittal plane generates highly precise information about how movement is impaired. To perform this procedure, reflective markers are placed on a hind limb to detect joint movement while a mouse is walking on a treadmill. Motion analysis software is used to measure movement of the markers during walking. Kinematic gait parameters are then derived from the resultant data. We show how these gait parameters can be used to quantify impaired movements of the hip, knee, and ankle joints in EAE. These techniques may be used to better understand disease mechanisms and identify potential treatments for MS and other neurodegenerative disorders that impair mobility.
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15
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Nichols M, Elustondo PA, Warford J, Thirumaran A, Pavlov EV, Robertson GS. Global ablation of the mitochondrial calcium uniporter increases glycolysis in cortical neurons subjected to energetic stressors. J Cereb Blood Flow Metab 2017; 37:3027-3041. [PMID: 27909264 PMCID: PMC5536808 DOI: 10.1177/0271678x16682250] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The effects of global mitochondrial calcium (Ca2+) uniporter (MCU) deficiency on hypoxic-ischemic (HI) brain injury, neuronal Ca2+ handling, bioenergetics and hypoxic preconditioning (HPC) were examined. Forebrain mitochondria isolated from global MCU nulls displayed markedly reduced Ca2+ uptake and Ca2+-induced opening of the membrane permeability transition pore. Despite evidence that these effects should be neuroprotective, global MCU nulls and wild-type (WT) mice suffered comparable HI brain damage. Energetic stress enhanced glycolysis and depressed Complex I activity in global MCU null, relative to WT, cortical neurons. HI reduced forebrain NADH levels more in global MCU nulls than WT mice suggesting that increased glycolytic consumption of NADH suppressed Complex I activity. Compared to WT neurons, pyruvate dehydrogenase (PDH) was hyper-phosphorylated in MCU nulls at several sites that lower the supply of substrates for the tricarboxylic acid cycle. Elevation of cytosolic Ca2+ with glutamate or ionomycin decreased PDH phosphorylation in MCU null neurons suggesting the use of alternative mitochondrial Ca2+ transport. Under basal conditions, global MCU nulls showed similar increases of Ca2+ handling genes in the hippocampus as WT mice subjected to HPC. We propose that long-term adaptations, common to HPC, in global MCU nulls compromise resistance to HI brain injury and disrupt HPC.
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Affiliation(s)
- Matthew Nichols
- 1 Faculty of Medicine, Department of Pharmacology, Brain Repair Centre, Life Sciences Research Institute, Dalhousie University, Halifax, Canada
| | - Pia A Elustondo
- 2 Faculty of Medicine, Department of Physiology and Biophysics, Dalhousie University, Halifax, Canada
| | - Jordan Warford
- 3 Faculty of Medicine, Department of Pathology, Dalhousie University, Halifax, Canada
| | - Aruloli Thirumaran
- 1 Faculty of Medicine, Department of Pharmacology, Brain Repair Centre, Life Sciences Research Institute, Dalhousie University, Halifax, Canada
| | - Evgeny V Pavlov
- 4 Department of Basic Sciences, College of Dentistry, New York University, New York, NY, USA
| | - George S Robertson
- 1 Faculty of Medicine, Department of Pharmacology, Brain Repair Centre, Life Sciences Research Institute, Dalhousie University, Halifax, Canada.,5 Department of Psychiatry, QEII Health Sciences Centre, Halifax, Canada
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16
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Contractor HH, Johnson PR, Chadwick DR, Robertson GS, London NJ. The Effect of UW Solution and Its Components on the Collagenase Digestion of Human and Porcine Pancreas. Cell Transplant 2017; 4:615-9. [PMID: 8714783 DOI: 10.1177/096368979500400611] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
University of Wisconsin (UW) solution is used extensively as a cold storage solution during the procurement and transport of the pancreas prior to islet isolation. However, it has been observed that UW inhibits the collagenase digestion phase of human but not porcine islet isolation, resulting in poor islet yields and islets of poor viability. The aim of this study was, therefore, to confirm this species difference and to determine which components of UW are responsible for the inhibition in the human. In the initial experiment, blocks of human and porcine pancreas (n = 7) were incubated in test tubes containing collagenase at a concentration of 4 mg/mL at 37°C dissolved in 4 mL of either Hanks' solution or UW. Every 5 min the tubes were manually shaken and the degree of tissue dissociation scored on a scale of + and +++. Our results confirm the inhibition of collagenase digestion in the human but not the pig. Using the same methodology, we then investigated the components of UW that were causing the observed inhibition in the human pancreas (n = 7). This time the collagenase was dissolved in individual or combinations of UW components. Using Hank's as a control, the results were then expressed as a median ratio. The components found to be most inhibitory were magnesium, the Na+/K+ ratio, hydroxyethyl starch (HES), and adenosine. Allopurinol in combination with either lactobionate or glutathione was markedly inhibitory (i.e., median ratio 1.8 and 1.9, respectively). The most inhibitory solution tested was a combination of the three components raffinose, glutathione, and lactobionate (median ratio 2.1). This combination was almost as inhibitory as UW itself (median ratio 2.7). These findings are essential for the development of effective cold-storage solutions for the human pancreas that do not inhibit the subsequent collagenase digestion phase of islet isolation.
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Affiliation(s)
- H H Contractor
- Department of Surgery, University of Leicester, Royal Infirmatory, UK
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17
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Fiander MD, Stifani N, Nichols M, Akay T, Robertson GS. Kinematic gait parameters are highly sensitive measures of motor deficits and spinal cord injury in mice subjected to experimental autoimmune encephalomyelitis. Behav Brain Res 2017; 317:95-108. [DOI: 10.1016/j.bbr.2016.09.034] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Revised: 09/12/2016] [Accepted: 09/14/2016] [Indexed: 12/13/2022]
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18
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Elustondo PA, Nichols M, Negoda A, Thirumaran A, Zakharian E, Robertson GS, Pavlov EV. Mitochondrial permeability transition pore induction is linked to formation of the complex of ATPase C-subunit, polyhydroxybutyrate and inorganic polyphosphate. Cell Death Discov 2016; 2:16070. [PMID: 27924223 PMCID: PMC5137186 DOI: 10.1038/cddiscovery.2016.70] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 08/10/2016] [Accepted: 08/19/2016] [Indexed: 12/25/2022] Open
Abstract
Mitochondrial permeability transition pore (mPTP) opening allows free movement of ions and small molecules leading to mitochondrial membrane depolarization and ATP depletion that triggers cell death. A multi-protein complex of the mitochondrial ATP synthase has an essential role in mPTP. However, the molecular identity of the central 'pore' part of mPTP complex is not known. A highly purified fraction of mammalian mitochondria containing C-subunit of ATPase (C-subunit), calcium, inorganic polyphosphate (polyP) and polyhydroxybutyrate (PHB) forms ion channels with properties that resemble the native mPTP. We demonstrate here that amount of this channel-forming complex dramatically increases in intact mitochondria during mPTP activation. This increase is inhibited by both Cyclosporine A, an inhibitor of mPTP and Ruthenium Red, an inhibitor of the Mitochondrial Calcium Uniporter. Similar increases in the amount of complex formation occurs in areas of mouse brain damaged by ischemia-reperfusion injury. These findings suggest that calcium-induced mPTP is associated with de novo assembly of a channel comprising C-subunit, polyP and PHB.
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Affiliation(s)
- P A Elustondo
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University , Halifax, NS, B3H 4R2 Canada
| | - M Nichols
- Departments of Psychiatry and Pharmacology, Brain Repair Centre, Faculty of Medicine Dalhousie University , Halifax, NS, B3H 4R2f Canada
| | - A Negoda
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University , Halifax, NS, B3H 4R2 Canada
| | - A Thirumaran
- Departments of Psychiatry and Pharmacology, Brain Repair Centre, Faculty of Medicine Dalhousie University , Halifax, NS, B3H 4R2f Canada
| | - E Zakharian
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine , 1 Illini Drive, Peoria, IL 61605, USA
| | - G S Robertson
- Departments of Psychiatry and Pharmacology, Brain Repair Centre, Faculty of Medicine Dalhousie University , Halifax, NS, B3H 4R2f Canada
| | - E V Pavlov
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, NS, B3H 4R2 Canada; Department of Basic Sciences, New York University, College of Dentistry, 345 East 24th Street, New York, NY 10010, USA
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Elustondo PA, Nichols M, Robertson GS, Pavlov EV. Mitochondrial Ca2+ uptake pathways. J Bioenerg Biomembr 2016; 49:113-119. [DOI: 10.1007/s10863-016-9676-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 09/05/2016] [Indexed: 12/19/2022]
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20
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Profitt MF, Deurveilher S, Robertson GS, Rusak B, Semba K. Disruptions of Sleep/Wake Patterns in the Stable Tubule Only Polypeptide (STOP) Null Mouse Model of Schizophrenia. Schizophr Bull 2016; 42:1207-15. [PMID: 26940700 PMCID: PMC4988734 DOI: 10.1093/schbul/sbw017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Disruption of sleep/wake cycles is common in patients with schizophrenia and correlates with cognitive and affective abnormalities. Mice deficient in stable tubule only polypeptide (STOP) show cognitive, behavioral, and neurobiological deficits that resemble those seen in patients with schizophrenia, but little is known about their sleep phenotype. We characterized baseline sleep/wake patterns and recovery sleep following sleep deprivation in STOP null mice. Polysomnography was conducted in adult male STOP null and wild-type (WT) mice under a 12:12 hours light:dark cycle before, during, and after 6 hours of sleep deprivation during the light phase. At baseline, STOP null mice spent more time awake and less time in non-rapid eye movement sleep (NREMS) over a 24-hour period, with more frequent transitions between wake and NREMS, compared to WT mice, especially during the dark phase. The distributions of wake, NREMS and REMS across the light and the dark phases differed by genotype, and so did features of the electroencephalogram (EEG). Following sleep deprivation, both genotypes showed homeostatic increases in sleep duration, with no significant genotype differences in the initial compensatory increase in sleep intensity (EEG delta power). These results indicate that STOP null mice sleep less overall, and their sleep and wake periods are more fragmented than those of WT mice. These features in STOP null mice are consistent with the sleep patterns observed in patients with schizophrenia.
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Affiliation(s)
- Maxine F. Profitt
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - Samuel Deurveilher
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - George S. Robertson
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada;,Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
| | - Benjamin Rusak
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada;,Department of Pharmacology, Dalhousie University, Halifax, NS, Canada;,Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - Kazue Semba
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS, Canada; Department of Psychiatry, Dalhousie University, Halifax, NS, Canada; Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS, Canada
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21
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Nichols M, Zhang J, Polster BM, Elustondo PA, Thirumaran A, Pavlov EV, Robertson GS. Synergistic neuroprotection by epicatechin and quercetin: Activation of convergent mitochondrial signaling pathways. Neuroscience 2015; 308:75-94. [PMID: 26363153 DOI: 10.1016/j.neuroscience.2015.09.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 08/25/2015] [Accepted: 09/03/2015] [Indexed: 01/08/2023]
Abstract
In view of evidence that increased consumption of epicatechin (E) and quercetin (Q) may reduce the risk of stroke, we have measured the effects of combining E and Q on mitochondrial function and neuronal survival following oxygen-glucose deprivation (OGD). Relative to mouse cortical neuron cultures pretreated (24h) with either E or Q (0.1-10μM), E+Q synergistically attenuated OGD-induced neuronal cell death. E, Q and E+Q (0.3μM) increased spare respiratory capacity but only E+Q (0.3μM) preserved this crucial parameter of neuronal mitochondrial function after OGD. These improvements were accompanied by corresponding increases in cyclic AMP response element binding protein (CREB) phosphorylation and the expression of CREB-target genes that promote neuronal survival (Bcl-2) and mitochondrial biogenesis (PGC-1α). Consistent with these findings, E+Q (0.1 and 1.0μM) elevated mitochondrial gene expression (MT-ND2 and MT-ATP6) to a greater extent than E or Q after OGD. Q (0.3-3.0μM), but not E (3.0μM), elevated cytosolic calcium (Ca(2+)) spikes and the mitochondrial membrane potential. Conversely, E and E+Q (0.1 and 0.3μM), but not Q (0.1 and 0.3μM), activated protein kinase B (Akt). Nitric oxide synthase (NOS) inhibition with L-N(G)-nitroarginine methyl ester (1.0μM) blocked neuroprotection by E (0.3μM) or Q (1.0μM). Oral administration of E+Q (75mg/kg; once daily for 5days) reduced hypoxic-ischemic brain injury. These findings suggest E and Q activate Akt- and Ca(2+)-mediated signaling pathways that converge on NOS and CREB resulting in synergistic improvements in neuronal mitochondrial performance which confer profound protection against ischemic injury.
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Affiliation(s)
- M Nichols
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Brain Repair Centre, Faculty of Medicine, Dalhousie University, Life Sciences Research Institute, 1348 Summer Street, P.O. Box 15000, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
| | - J Zhang
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Brain Repair Centre, Faculty of Medicine, Dalhousie University, Life Sciences Research Institute, 1348 Summer Street, P.O. Box 15000, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
| | - B M Polster
- Department of Anesthesiology, Center for Shock Trauma and Anesthesiology Research, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - P A Elustondo
- Department of Physiology and Biophysics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
| | - A Thirumaran
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Brain Repair Centre, Faculty of Medicine, Dalhousie University, Life Sciences Research Institute, 1348 Summer Street, P.O. Box 15000, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
| | - E V Pavlov
- Department of Basic Sciences, College of Dentistry, New York University, 345 East 24th Street, New York, NY 10010, USA.
| | - G S Robertson
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Department of Psychiatry, 5909 Veterans' Memorial Lane, 8th Floor Abbie J. Lane Memorial Building, QEII Health Sciences Centre, Halifax, Nova Scotia B3H 2E2, Canada.
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Jie H, Tao S, Liu L, Xia L, Charko A, Yu Z, Bance M, Yin S, Robertson GS, Wang J. Cochlear protection against cisplatin by viral transfection of X-linked inhibitor of apoptosis protein across round window membrane. Gene Ther 2015; 22:546-52. [PMID: 25809464 DOI: 10.1038/gt.2015.22] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 02/15/2015] [Accepted: 02/18/2015] [Indexed: 01/23/2023]
Abstract
We have previously demonstrated that both age-related and noise-induced hearing loss are reduced in transgenic mice that ubiquitously overexpress X-linked inhibitor of apoptosis protein (XIAP). In view of the therapeutic implications of these findings, we have developed a minimally invasive surgical method to deliver adenoid-associated virus (AAV) across the round window membrane (RWM) of the cochlea, enabling efficient gene transfer to hair cells and sensory neurons in this enclosed structure. This RWM approach was used in the present study to evaluate the effectiveness of AAV-mediated XIAP overexpression in protecting against cisplatin-induced ototoxicity. Two weeks following surgery, AAV-derived XIAP was detected in the majority of inner and outer hair cells, resulting in a threefold elevation of this antiapoptotic protein in the cochlea. The protection of AAV-mediated XIAP overexpression was evaluated in animals treated with cisplatin at a dose of 4 mg kg(-1) per day for 4-7 consecutive days. The XIAP overexpression was found to attenuate cisplatin-induced hearing loss by ~22 dB. This was accompanied by a reduction of the loss of vulnerable hair cells and sensory neurons in the cochlea by 13%.
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Affiliation(s)
- H Jie
- Department of Otolaryngology, Affiliated Sixth People's Hospital of Shanghai Jiao Tong University, Shanghai, China
| | - S Tao
- Department of Physiology, Medical College, Southeast University, Nanjing, China
| | - L Liu
- Department of Physiology, Medical College, Southeast University, Nanjing, China
| | - L Xia
- Department of Otolaryngology, Affiliated Sixth People's Hospital of Shanghai Jiao Tong University, Shanghai, China
| | - A Charko
- School of Human Communication Disorder, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Z Yu
- School of Human Communication Disorder, Dalhousie University, Halifax, Nova Scotia, Canada
| | - M Bance
- Department of Surgery, Division of Otolaryngology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - S Yin
- Department of Otolaryngology, Affiliated Sixth People's Hospital of Shanghai Jiao Tong University, Shanghai, China
| | - G S Robertson
- Departments of Psychiatry and Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - J Wang
- 1] Department of Otolaryngology, Affiliated Sixth People's Hospital of Shanghai Jiao Tong University, Shanghai, China [2] School of Human Communication Disorder, Dalhousie University, Halifax, Nova Scotia, Canada
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Warford J, Jones QR, Nichols M, Sullivan V, Rupasinghe HV, Robertson GS. The flavonoid-enriched fraction AF4 suppresses neuroinflammation and promotes restorative gene expression in a mouse model of experimental autoimmune encephalomyelitis. J Neuroimmunol 2014; 268:71-83. [DOI: 10.1016/j.jneuroim.2014.01.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 01/10/2014] [Accepted: 01/14/2014] [Indexed: 11/16/2022]
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Grant J, Parker K, Moore CS, Keddy PGW, Mayne M, Robertson GS. Over-expression of X-linked inhibitor of apoptosis protein modulates multiple aspects of neuronal Ca2+ signaling. Neurochem Res 2013; 38:847-56. [PMID: 23397285 DOI: 10.1007/s11064-013-0989-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 01/15/2013] [Accepted: 01/29/2013] [Indexed: 11/25/2022]
Abstract
X-linked inhibitor of apoptosis (XIAP) protects and preserves the function of neurons in both in vitro and in vivo models of excitotoxicity. Since calcium (Ca(2+)) overload is a pivotal event in excitotoxic neuronal cell death, we have determined whether XIAP over-expression influences Ca(2+)-signaling in primary cultures of mouse cortical neurons. Using cortical neuron cultures derived from wild-type (Wt) mice transiently transfected with XIAP or from transgenic mice that over-express XIAP, we show that XIAP opposes the rise in intracellular Ca(2+) concentration by a variety of triggers. Relative to control neurons, XIAP over-expression produced a slight, but significant, elevation of resting Ca(2+) concentrations. By contrast, the rise in intracellular Ca(2+) concentrations produced by N-methyl-D-aspartate receptor stimulation and voltage gated Ca(2+) channel activation were markedly attenuated by XIAP over-expression. The release of Ca(2+) from intracellular stores induced by the sarco/endoplasmic reticulum Ca(2+) ATPase inhibitor thapsigargin was also inhibited in neurons transiently transfected with XIAP. The pan-caspase inhibitor zVAD did not, however, diminish the rise in intracellular Ca(2+) concentrations elicited by L-glutamate suggesting that XIAP influences Ca(2+) signaling in a caspase-independent manner. Taken together, these findings demonstrate that the ability of XIAP to block excessive rises in intracellular Ca(2+) by a variety of triggers may contribute to the neuroprotective effects of this anti-apoptotic protein.
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Affiliation(s)
- Jeff Grant
- Institute for Nutrisciences and Health, National Research Council of Canada, Charlottetown PEI, C1A 4P3, Canada.
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Keddy PGW, Dunlop K, Warford J, Samson ML, Jones QRD, Rupasinghe HPV, Robertson GS. Neuroprotective and anti-inflammatory effects of the flavonoid-enriched fraction AF4 in a mouse model of hypoxic-ischemic brain injury. PLoS One 2012; 7:e51324. [PMID: 23251498 PMCID: PMC3520852 DOI: 10.1371/journal.pone.0051324] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Accepted: 10/31/2012] [Indexed: 11/23/2022] Open
Abstract
We report here neuroprotective and anti-inflammatory effects of a flavonoid-enriched fraction isolated from the peel of Northern Spy apples (AF4) in a mouse of model of hypoxic-ischemic (HI) brain damage. Oral administration of AF4 (50 mg/kg, once daily for 3 days) prior to 50 min of HI completely prevented motor performance deficits assessed 14 days later that were associated with marked reductions in neuronal cell loss in the dorsal hippocampus and striatum. Pre-treatment with AF4 (5, 10, 25 or 50 mg/kg, p.o.; once daily for 3 days) produced a dose-dependent reduction in HI-induced hippocampal and striatal neuron cell loss, with 25 mg/kg being the lowest dose that achieved maximal neuroprotection. Comparison of the effects of 1, 3 or 7 doses of AF4 (25 mg/kg; p.o.) prior to HI revealed that at least 3 doses of AF4 were required before HI to reduce neuronal cell loss in both the dorsal hippocampus and striatum. Quantitative RT-PCR measurements revealed that the neuroprotective effects of AF4 (25 mg/kg; p.o.; once daily for 3 days) in the dorsal hippocampus were associated with a suppression of HI-induced increases in the expression of IL-1β, TNF-α and IL-6. AF4 pre-treatment enhanced mRNA levels for pro-survival proteins such as X-linked inhibitor of apoptosis and erythropoietin following HI in the dorsal hippocampus and striatum, respectively. Primary cultures of mouse cortical neurons incubated with AF4 (1 µg/ml), but not the same concentrations of either quercetin or quercetin-3-O-glucose or its metabolites, were resistant to cell death induced by oxygen glucose deprivation. These findings suggest that the inhibition of HI-induced brain injury produced by AF4 likely involves a transcriptional mechanism resulting from the co-operative actions of various phenolics in this fraction which not only reduce the expression of pro-inflammatory mediators but also enhance pro-survival gene signalling.
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Affiliation(s)
- Paul G. W. Keddy
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kate Dunlop
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jordan Warford
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michel L. Samson
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Quinton R. D. Jones
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
| | - H. P. Vasantha Rupasinghe
- Department of Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada
| | - George S. Robertson
- Department of Pharmacology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Psychiatry, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
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Jones QRD, Warford J, Rupasinghe HPV, Robertson GS. Target-based selection of flavonoids for neurodegenerative disorders. Trends Pharmacol Sci 2012; 33:602-10. [PMID: 22980637 DOI: 10.1016/j.tips.2012.08.002] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 08/09/2012] [Accepted: 08/15/2012] [Indexed: 11/26/2022]
Abstract
Habitual consumption of dietary flavonoids known to improve mitochondrial bioenergetics and inhibit various secondary sources of reactive oxygen species (ROS) reduces the risk for neurodegenerative disorders such as Parkinson's disease (PD), stroke, and Alzheimer's disease (AD). Combining specific dietary flavonoids selected on the basis of oral bioavailability, brain penetration, and the inhibition of multiple processes responsible for excessive ROS production may be a viable approach for the prevention and treatment of neurodegenerative disorders. Inclusion of flavonoids that raise cAMP levels in the brain may be of additional benefit by reducing the production of proinflammatory mediators and stimulating the transcriptional machinery necessary for mitochondrial biosynthesis. Preclinical models suggest that flavonoids reduce hearing loss resulting from treatment with the chemotherapeutic drug cisplatin by opposing the excessive production of ROS and proinflammatory mediators implicated in PD, stroke, and AD. Flavonoid combinations optimized for efficacy in models of cisplatin-induced hearing loss (CIHL) may therefore have therapeutic utility for neurodegenerative disorders.
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Affiliation(s)
- Quinton R D Jones
- Department of Pharmacology, Faculty of Medicine, 1459 Oxford Street, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2
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Ji X, Rivers L, Zielinski Z, Xu M, MacDougall E, Stephen J, Zhang S, Wang Y, Chapman RG, Keddy P, Robertson GS, Kirby CW, Embleton J, Worrall K, Murphy A, De Koeyer D, Tai H, Yu L, Charter E, Zhang J. Quantitative analysis of phenolic components and glycoalkaloids from 20 potato clones and in vitro evaluation of antioxidant, cholesterol uptake, and neuroprotective activities. Food Chem 2012. [DOI: 10.1016/j.foodchem.2011.08.065] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Wang H, Murphy R, Taaffe D, Yin S, Xia L, Hauswirth WW, Bance M, Robertson GS, Wang J. Efficient cochlear gene transfection in guinea-pigs with adeno-associated viral vectors by partial digestion of round window membrane. Gene Ther 2011. [PMID: 21697953 DOI: 10.1038/gt.2011.91gt201191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The auditory portion of the inner ear, the cochlea, is an ideal organ for local gene transfection owing to its relative isolation. Various carriers have been tested for cochlear gene transfection. To date, viral vectors appear to have much higher transfection efficacy than non-viral mechanisms. Among these vectors, recombinant adeno-associated virus (rAAV) vectors have several advantages such as being non-pathogenic and the ability to produce prolonged gene expression in various cell types. However, rAAV vectors cannot pass through the intact round window membrane (RWM), otherwise a very attractive approach to access the human inner ear. In this study, performed in guinea-pigs, we describe a method to increase the permeability of RWM to rAAV vectors by partial digestion with collagenase solution. Elevated delivery of rAAV across the partially digested RWM increased transfection efficacy to a satisfactory level, even though it was still lower than that achieved by direct cochleostomy injection. Functional tests (auditory brainstem responses) showed that this enzymatic manipulation did not cause permanent hearing loss if applied appropriately. Morphological observations suggested that the damage to RWM caused by partial digestion healed within four weeks. Taken together, these findings suggest that partial digestion of the RWM is a safe and effective method for increasing the transfection of cochlear sensory cells with rAAV.
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Affiliation(s)
- H Wang
- Department of Otolaryngology, Affiliated Sixth People's Hospital of Shanghai Jiao Tong University, Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China
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Crocker CE, Khan S, Cameron MD, Robertson HA, Robertson GS, LoGrasso P. JNK Inhibition Protects Dopamine Neurons and Provides Behavioral Improvement in a Rat 6-hydroxydopamine Model of Parkinson's Disease. ACS Chem Neurosci 2011; 2:207-212. [PMID: 21666838 DOI: 10.1021/cn1001107] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Parkinson's disease (PD) results from the loss of dopamine neurons located in the substantia nigra pars compacta (SNpc) that project to the striatum. A therapeutic has yet to be identified that halts this neurodegenerative process, and as such, development of a brain penetrant small molecule neuroprotective agent would represent a significant advancement in the treatment of the disease. To fill this void we developed an aminopyrimidine JNK inhibitor (SR-3306) that reduced the loss of dopaminergic cell bodies in the SNpc and their terminals in the striatum produced by unilateral injection of 6-hydroxydopamine (6-OHDA) into the nigrostriatal pathway. Administration of SR-3306 [10 mg/kg/day (s.c.) for 14 days] increased the number of tyrosine hydroxylase immunoreactive (TH(+)) neurons in the SNpc by six-fold and reduced the loss of the TH(+) terminals in the striatum relative to the corresponding side of 6-OHDA-lesioned rats that received only vehicle (p<0.05). In addition, SR-3306 [10 mg/kg/day (s.c.) for 14 days] decreased d-amphetamine-induced circling by 87% compared to 6-OHDA-lesioned animals given vehicle. Steady-state brain levels of SR-3306 at day 14 were 347 nM, which was approximately two-fold higher than the cell-based IC(50) for this compound. Finally, immunohistochemical staining for phospho-c-jun (p-c-jun) revealed that SR-3306 [10 mg/kg/day (s.c.) for 14 days] produced a 2.3-fold reduction of the number of immunoreactive neurons in the SNpc relative to vehicle treated rats. Collectively, these data suggest that orally bioavailable JNK inhibitors may be useful neuroprotective agents for the treatment of Parkinson's disease.
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Affiliation(s)
- Candice E. Crocker
- Departments of Psychiatry and Pharmacology, Sir Charles Tuper Medical Building, Faculty of Medicine, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, Canada B3H 1X5
| | - Susan Khan
- Department of Molecular Therapeutics and Translational Research Institute, The Scripps Research Institute, Scripps Florida, 130 Scripps Way #A2A, Jupiter, Florida 33458, United States
| | - Michael D. Cameron
- Department of Molecular Therapeutics and Translational Research Institute, The Scripps Research Institute, Scripps Florida, 130 Scripps Way #A2A, Jupiter, Florida 33458, United States
| | - Harold A. Robertson
- Departments of Psychiatry and Pharmacology, Sir Charles Tuper Medical Building, Faculty of Medicine, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, Canada B3H 1X5
| | - George S. Robertson
- Departments of Psychiatry and Pharmacology, Sir Charles Tuper Medical Building, Faculty of Medicine, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, Canada B3H 1X5
| | - Philip LoGrasso
- Department of Molecular Therapeutics and Translational Research Institute, The Scripps Research Institute, Scripps Florida, 130 Scripps Way #A2A, Jupiter, Florida 33458, United States
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Abstract
INTRODUCTION MS is a heterogeneous disorder that requires the development of better diagnostics to identify disease subtypes enabling appropriate therapeutic intervention at an early stage of the disease. Accumulating evidence indicates that members of the inhibitor of apoptosis (IAP) family play an important role in the pathogenesis of MS by reducing the apoptotic elimination of autoreactive immune cells. AREAS COVERED The authors describe improved animal modeling strategies to identify compounds that have immunomodulatory, neurorestorative and neuroprotective properties. In addition, the authors propose new approaches to better model cognitive dysfunction in MS, which will aid the development of novel therapeutics for this complex disorder. The paper provides the reader with an appreciation for the diagnostic and therapeutic potential of apoptosis-related proteins for MS. EXPERT OPINION Recent evidence suggests that increased resistance of autoreactive immune cells to apoptotic elimination is a contributing factor to both disease susceptibility and progression in MS. This occurs, at least in part, because of elevated levels of the IAP family of anti-apoptotic genes that display distinct expression profiles associated with different subtypes of MS. The authors believe that the detection and targeting of members of the IAP family can provide better drugs for MS. Particularly, the authors feel that the overexpression of IAPs in animal models can provide novel insights into MS for both its pathogenesis and the discovery of new lead compounds.
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Affiliation(s)
- Jordan Warford
- Dalhousie University , Department of Pharmacology , Halifax, NS B3H 1X5 , Canada
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Hebb ALO, Bhan V, Wishart AD, Moore CS, Robertson GS. Human kallikrein 6 cerebrospinal levels are elevated in multiple sclerosis. Curr Drug Discov Technol 2011; 7:137-40. [PMID: 20836755 DOI: 10.2174/157016310793180611] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 06/21/2010] [Indexed: 11/22/2022]
Abstract
The protease, human kallikrein-related peptidase 6 (hK6) is derived from activated macrophages in the central nervous system (CNS) and may contribute to pathology observed in multiple sclerosis (MS). In the present study, we compared serum and cerebrospinal fluid (CSF) protein concentrations of human kallikrein-related peptidase 6 derived from neurological controls and patients diagnosed with advanced multiple sclerotic disease. Mean serum levels of human kallikrein-related peptidase 6 were similar in neurological controls and patients diagnosed with relapsing-remitting (RR), secondary progressive (SP) and primary progressive (PP) multiple sclerosis with mean levels ranging from 3.5 to 3.75 ng/ml. Patients diagnosed with advanced multiple sclerosis showed mean CSF levels (29 ng/ml) that were significantly higher than neurological controls (25.5 ng/ml). Determining CSF concentrations of human kallikrein-related peptidase 6 may therefore have diagnostic value in MS.
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Affiliation(s)
- Andrea L O Hebb
- Department of Pharmacology, Dalhousie University, Halifax, NS B3H 1X5, Canada.
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Wang J, Tymczyszyn N, Yu Z, Yin S, Bance M, Robertson GS. Overexpression of X-linked inhibitor of apoptosis protein protects against noise-induced hearing loss in mice. Gene Ther 2011; 18:560-8. [PMID: 21228883 DOI: 10.1038/gt.2010.172] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Apoptosis is responsible for cochlear cell death induced by noise. Here, we show that transgenic (TG) mice that overexpress X-linked inhibitor of apoptosis protein (XIAP) under control of the ubiquitin promoter display reduced hearing loss and cochlear damage induced by acoustic overstimulation (125 dB sound pressure level, 6 h) compared with wild-type (WT) littermates. Hearing status was evaluated using the auditory brainstem response (ABR), whereas cochlear damage was assessed by counts of surviving hair cells (HCs) and spiral ganglion neurons (SGNs) as well as their fibers to HCs. Significantly smaller threshold shifts were found for TG mice than WT littermates. Correspondingly, the TG mice also showed a reduced loss of HCs, SGNs and their fibers to HCs. HC loss was limited to the basal end of the cochlea that detects high frequency sound. In contrast, the ABRs demonstrated a loss of hearing sensitivity across the entire frequency range tested (2-32 kHz) indicating that the hearing loss could not be fully attributed to HC loss alone. The TG mice displayed superior hearing sensitivity over this whole range, suggesting that XIAP overexpression reduces noise-induced hearing loss not only by protecting HCs but also other components of the cochlea.
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Affiliation(s)
- J Wang
- School of Human Communication Disorder, Dalhousie University, Halifax, Nova Scotia, Canada.
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Hebb ALO, Moore CS, Bhan V, Robertson GS. Effects of IFN-B on TRAIL and Decoy Receptor Expression in Different Immune Cell Populations from MS Patients with Distinct Disease Subtypes. Autoimmune Dis 2010; 2011:485752. [PMID: 21253524 PMCID: PMC3022173 DOI: 10.4061/2011/485752] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 11/16/2010] [Indexed: 12/11/2022] Open
Abstract
Using quantitative RT-PCR, we compared mRNA levels for TRAIL [tumor necrosis factor (TNF)-related apoptosis-inducing ligand] and its receptors in various immune cell subsets derived from the peripheral blood of untreated normal subjects (NS) and patients with distinct subtypes of multiple sclerosis (MS): active relapsing-remitting MS (RRA), quiescent relapsing-remitting MS (RRQ), secondary-progressive MS (SPMS) or primary-progressive MS (PPMS). Consistent with a role for TRAIL in the mechanism of action of interferon-β (IFN-β), TRAIL mRNA levels were increased in monocytes from patients clinically responsive to IFN-β (RRQ) but not those unresponsive to this therapeutic (RRA). TRAIL-R3 (decoy receptor) expression was elevated in T cells from untreated RRMS patients while IFN-β therapy reversed this increase suggesting that IFN-β may promote the apoptotic elimination of autoreactive T cells by increasing the amount of TRAIL available to activate TRAIL death receptors. Serum concentrations of soluble TRAIL were increased to a similar extent by IFN-β therapy in RRQ, RRA and SPMS patients that had not generated neutralizing antibodies against this cytokine. Although our findings suggest altered TRAIL signaling may play a role in MS pathogenesis and IFN-β therapy, they do not support use of TRAIL as a surrogate marker for clinical responsiveness to this therapeutic.
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Affiliation(s)
- Andrea L O Hebb
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada B3H 1X5
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Kajitani K, Thorne M, Samson M, Robertson GS. Nitric oxide synthase mediates the ability of darbepoetin alpha to improve the cognitive performance of STOP null mice. Neuropsychopharmacology 2010; 35:1718-28. [PMID: 20336057 PMCID: PMC3055482 DOI: 10.1038/npp.2010.36] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
STOP (stable tubule only polypeptide) null mice display neurochemical and behavioral abnormalities that resemble several well-recognized features of schizophrenia. Recent evidence suggests that the hematopoietic growth factor erythropoietin improves the cognitive performance of schizophrenics. The mechanism, however, by which erythropoietin is able to improve the cognition of schizophrenics is unclear. To address this question, we first determined whether acute administration of the erythropoietin analog known as darbepoetin alpha (D. alpha) improved performance deficits of STOP null mice in the novel objective recognition task (NORT). NORT performance of STOP null mice, but not wild-type littermates, was enhanced 3 h after a single injection of D. alpha (25 microg/kg, i.p.). Improved NORT performance was accompanied by elevated NADPH diaphorase staining in the ventral hippocampus as well as medial and cortical aspects of the amygdala, indicative of increased nitric oxide synthase (NOS) activity in these structures. NOS generates the intracellular messenger nitric oxide (NO) implicated in learning and memory. In keeping with this hypothesis, D. alpha significantly increased NO metabolite levels (nitrate and nitrite, NOx) in the hippocampus of both wild-type and STOP null mice. The NOS inhibitor, N (G)-nitro-L- arginine methyl ester (L-NAME; 25 mg/kg, i.p.), completely reversed the increase in hippocampal NOx levels produced by D. alpha. Moreover, L-NAME also inhibited the ability of D. alpha to improve the NORT performance of STOP null mice. Taken together, these observations suggest D. alpha enhances the NORT performance of STOP null mice by increasing production of NO.
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Affiliation(s)
- Kosuke Kajitani
- Department of Psychiatry, Sir Charles Tupper Medical Building, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michael Thorne
- Department of Psychiatry, Sir Charles Tupper Medical Building, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michel Samson
- Department of Psychiatry, Sir Charles Tupper Medical Building, Dalhousie University, Halifax, Nova Scotia, Canada
| | - George S Robertson
- Department of Psychiatry, Sir Charles Tupper Medical Building, Dalhousie University, Halifax, Nova Scotia, Canada,Department of Pharmacology, Sir Charles Tupper Medical Building, Dalhousie University, Halifax, Nova Scotia, Canada,Departments of Psychiatry and Pharmacology, Sir Charles Tupper Medical Building, Faculty of Medicine, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, Canada B3H 1X5, Tel: +1 902 494 1528, Fax: +1 902 494 1388, E-mail:
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Kajitani K, Wafa K, Pasumarthi KB, Robertson GS. Developmental expression of the cyclin D2 splice variant in postnatal Purkinje cells of the mouse cerebellum. Neurosci Lett 2010; 477:100-4. [DOI: 10.1016/j.neulet.2010.04.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 03/13/2010] [Accepted: 04/19/2010] [Indexed: 12/21/2022]
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Samson ML, Kajitani K, Robertson GS. Nitric-Oxide Synthase Mediates the Ability of Darbepoetin Alfa to Attenuate Pre-Existing Spatial Working Memory Deficits in Rats Subjected to Transient Global Ischemia. J Pharmacol Exp Ther 2010; 333:437-44. [DOI: 10.1124/jpet.110.165530] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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Soundararajan R, Sayat R, Robertson GS, Marignani PA. Triptolide: An inhibitor of a disintegrin and metalloproteinase 10 (ADAM10) in cancer cells. Cancer Biol Ther 2009; 8:2054-62. [PMID: 19783906 DOI: 10.4161/cbt.8.21.9803] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Triptolide, a diterpene triepoxide derived from Trypterygium wilfordii, is documented to have antitumor activity in a broad range of solid tumors and leukemia. The mechanisms that are involved in triptolide-mediated apoptosis or growth inhibition in cancer cells are not fully understood. We identified a disintegrin and metalloproteinase 10 (ADAM10) as a novel molecular target of triptolide using affinity chromatography and mass spectrometry. The identification was confirmed by western blot analysis using an anti-ADAM10 antibody. The expression of ADAM10 is enhanced in several tumors including leukemia and is involved in malignant cell growth and cancer progression. ADAM10 is a type 1 transmembrane glycoprotein that cleaves several plasma membrane proteins. We show that triptolide, at concentrations in the nM range, resulted in a significant decrease in ADAM10 expression followed by the appearance of ADAM10 cleaved product. Furthermore, triptolide reduced the viability of monocytic leukemic U937 cells. Triptolide treatment of MCF-7 breast cancer cells expressing ectopic ADAM10 or dominant negative ADAM10 (DN ADAM10) resulted in a decreased expression of ADAM10 with a concomitant increase in ADAM10 cleaved products. Moreover, siRNA-mediated knockdown of ADAM10 mRNA significantly affected the growth of MCF-7 cells. Interestingly, the combination of siRNA-mediated knockdown of ADAM10 mRNA expression and triptolide treatment lead to a further reduction in cell growth. Taken together, we provide evidence that ADAM10 is a novel target of triptolide, presenting a novel strategy to inhibit ADAM10 activity in tumorigenesis.
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Affiliation(s)
- Ramani Soundararajan
- Department of Pharmacology and Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dalhousie University, Halifax, NS, CA
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Thorne M, Moore CS, Robertson GS. Lack of TIMP-1 increases severity of experimental autoimmune encephalomyelitis: Effects of darbepoetin alfa on TIMP-1 null and wild-type mice. J Neuroimmunol 2009; 211:92-100. [DOI: 10.1016/j.jneuroim.2009.04.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 04/02/2009] [Accepted: 04/08/2009] [Indexed: 12/27/2022]
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Alirezaei M, Fox HS, Flynn CT, Moore CS, Hebb ALO, Frausto RF, Bhan V, Kiosses WB, Whitton JL, Robertson GS, Crocker SJ. Elevated ATG5 expression in autoimmune demyelination and multiple sclerosis. Autophagy 2009; 5:152-8. [PMID: 19066443 DOI: 10.4161/auto.5.2.7348] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Multiple sclerosis (MS) is an inflammatory central nervous system (CNS) disorder characterized by T cell-mediated demyelination. In MS, prolonged T cell survival and increased T cell proliferation have been linked to disease relapse and progression. Recently, the autophagy-related gene 5 (Atg5) has been shown to modulate T cell survival. In this study, we examined the expression of Atg5 using both a mouse model of autoimmune demyelination as well as blood and brain tissues from MS cases. Quantitative real-time PCR analysis of RNA isolated from blood samples of experimental autoimmune encephalomyelitis (EAE) mice revealed a strong correlation between Atg5 expression and clinical disability.Analysis of protein extracted from these cells confirmed both upregulation and post-translational modification of Atg5, the latter of which was positively correlated with EAE severity. Analysis of RNA extracted from T cells isolated by negative selection indicated that Atg5 expression was significantly elevated in individuals with active relapsing-remitting MS compared to non-diseased controls. Brain tissue sections from relapsing-remitting MS cases examined by immunofluorescent histochemistry suggested that encephalitogenic T cells are a source of Atg5 expression in MS brain samples. Together these data suggest that increased T cell expression of Atg5 may contribute to inflammatory demyelination in MS.
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Affiliation(s)
- Mehrdad Alirezaei
- Molecular and Integrative Neurosciences Department, The Scripps Research Institute, La Jolla, California 92037, USA.
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Alexander K, Bachmann K, Bigelow J, Bress W, Byers JP, Calabrese E, Chiu JF, Erhardt P, Grabovich A, Holcik M, Hacker M, Hazlehurst L, He QY, Kenakin T, LaCasse EC, Lazo JS, Leggas M, Lounsberry K, McNamara PJ, Petkov GV, Robertson GS, Sarver JG, Taft DR, Tang P, Taylor WR, Tillman TS, Wang Y, Xu Y. Contributors. Pharmacology 2009. [DOI: 10.1016/b978-0-12-369521-5.00024-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Wang J, Menchenton T, Yin S, Yu Z, Bance M, Morris DP, Moore CS, Korneluk RG, Robertson GS. Over-expression of X-linked inhibitor of apoptosis protein slows presbycusis in C57BL/6J mice. Neurobiol Aging 2008; 31:1238-49. [PMID: 18755525 DOI: 10.1016/j.neurobiolaging.2008.07.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Revised: 07/05/2008] [Accepted: 07/23/2008] [Indexed: 10/21/2022]
Abstract
Apoptosis of cochlear cells plays a significant role in age-related hearing loss or presbycusis. In this study, we evaluated whether over-expression of the anti-apoptotic protein known as X-linked Inhibitor of Apoptosis Protein (XIAP) slows the development of presbycusis. We compared the age-related hearing loss between transgenic (TG) mice that over-express human XIAP tagged with 6-Myc (Myc-XIAP) on a pure C57BL/6J genetic background with wild-type (WT) littermates by measuring auditory brainstem responses. The result showed that TG mice developed hearing loss considerably more slowly than WT littermates, primarily within the high-frequency range. The average total hair cell loss was significantly less in TG mice than WT littermates. Although levels of Myc-XIAP in the ear remained constant at 2 and 14 months, there was a marked increase in the amount of endogenous XIAP from 2 to 14 months in the cochlea, but not in the brain, in both genotypes. These results suggest that XIAP over-expression reduces age-related hearing loss and hair cell death in the cochlea.
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Affiliation(s)
- Jian Wang
- The Affiliated Sixth People's Hospital, Otolaryngology Institute of Shanghai Jiao Tong University, Shanghai, China.
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Cowper-Smith CD, Anger GJA, Magal E, Norman MH, Robertson GS. Delayed administration of a potent cyclin dependent kinase and glycogen synthase kinase 3 beta inhibitor produces long-term neuroprotection in a hypoxia-ischemia model of brain injury. Neuroscience 2008; 155:864-75. [PMID: 18640243 DOI: 10.1016/j.neuroscience.2008.05.051] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2008] [Revised: 05/08/2008] [Accepted: 05/30/2008] [Indexed: 12/15/2022]
Abstract
We compared the neuroprotective efficacy of a potent and CNS-penetrant cyclin dependent kinase (CDK) and glycogen synthase kinase 3 beta (GSK3beta) inhibitor (Compound 1) in juvenile (postnatal day 21; P21) and adult C57Bl/6 mice (postnatal day 60; P60) using a model of hypoxic-ischemic brain injury (HI). Neuronal cell counts and density measures from brain sections stained with Cresyl Violet revealed that exposure of P21 mice to 60 min of HI resulted in extensive damage to the ipsilateral cornu ammonis 1 (CA1) region of the hippocampus (40% cell loss) and striatum (30% cell loss) 7 days later. Exposure of P60 mice to 40 min of HI produced a similar pattern of cell loss. Intraperitoneal administration of Compound 1 (3 mg/kg) 1, 5 and 9 h after 60 min of HI did not reduce brain injury in P21 mice relative to vehicle controls. By contrast, in P60 mice, this treatment significantly decreased cell loss in the ipsilateral hippocampus (10% cell loss) and striatum (15% loss) relative to vehicle controls. Terminal uridine deoxynucleotidyl transferase (TUNNEL) positive cell counts and infarct volume were also substantially reduced in P60 mice treated with Compound 1. A motor coordination test performed twice weekly until 5 weeks post-HI confirmed that Compound 1 produced long lasting functional recovery. Our results indicate that Compound 1 produced long lasting neuroprotective effects in adult but not juvenile mice suggesting that inhibition of the CDKs and GSK3beta plays a distinct neuroprotective role in the juvenile and adult brain.
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Affiliation(s)
- C D Cowper-Smith
- Department of Pharmacology, Dalhousie University, Sir Charles Tupper Medical Building, 5850 College Street, Halifax, Nova Scotia, Canada B3H 1X5
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Hebb ALO, Moore CS, Bhan V, Campbell T, Fisk JD, Robertson HA, Thorne M, Lacasse E, Holcik M, Gillard J, Crocker SJ, Robertson GS. Expression of the inhibitor of apoptosis protein family in multiple sclerosis reveals a potential immunomodulatory role during autoimmune mediated demyelination. Mult Scler 2008; 14:577-94. [DOI: 10.1177/1352458507087468] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A failure of autoreactive T cells to undergo apoptosis may contribute to the pathogenesis of multiple sclerosis (MS). The role of the inhibitor of apoptosis (IAP) family of anti-apoptotic proteins such as X-linked IAP (XIAP), human inhibitor of apoptosis-1 (HIAP-1), human inhibitor of apoptosis-2 (HIAP-2), neuronal apoptosis inhibitory protein (NAIP) and Survivin in relapsing–remitting, secondary-progressive, primary-progressive or benign forms of MS is unclear. We report here that expression of the IAP family of genes in peripheral blood samples and brain tissues from MS cases support a role for differential regulation of these potent anti-apoptotic proteins in the pathology of MS. XIAP mRNA and protein levels were elevated in peripheral blood mononuclear cells from patients with active disease relative to normal subjects. In patients with active MS, HIAP-1 and HIAP-2 mRNA levels were elevated in resting T cells while NAIP mRNA was increased in whole blood. In post-mortem MS brain tissue, XIAP and HIAP-1 in myelin lesions were co-localized with microglia and T cells, respectively. Only in primary-progressive patients was Survivin expression elevated suggestive of a distinct pathological basis for this subtype of MS. Taken together, these results suggest that patterns of inhibitor of apoptosis expression in immune cells may have value in distinguishing between MS subtypes and offer insight into the mechanisms responsible for their distinct clinical courses.
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Affiliation(s)
- ALO Hebb
- Department of Pharmacology, Dalhousie University, Halifax, NS, B3H 1X5, Canada
| | - CS Moore
- Department of Pharmacology, Dalhousie University, Halifax, NS, B3H 1X5, Canada
| | - V Bhan
- Department of Medicine (Neurology), Dalhousie University, Halifax, NS, B3H 1V7, Canada
| | - T Campbell
- Department of Medicine (Neurology), Dalhousie University, Halifax, NS, B3H 1V7, Canada
| | - JD Fisk
- Department of Psychiatry, Dalhousie University, Halifax, NS, B3H 2E2, Canada; Department of Psychology, QEII Health Sciences Centre, Halifax, NS, B3H 2E2, Canada
| | - HA Robertson
- Department of Pharmacology, Dalhousie University, Halifax, NS, B3H 1X5, Canada
| | - M Thorne
- Department of Pharmacology, Dalhousie University, Halifax, NS, B3H 1X5, Canada
| | - E Lacasse
- Aegera Therapeutics Inc., Nun’s Island (Montreal), PQ, H3E 1A8, Canada
| | - M Holcik
- Apoptosis Research Centre, Children's Hospital of Eastern Ontario, Ottawa, Ontario, KIH 8L1, Canada
| | - J Gillard
- Aegera Therapeutics Inc., Nun’s Island (Montreal), PQ, H3E 1A8, Canada
| | - SJ Crocker
- Molecular and Integrative Neuroscience Department, the Scripps Research Institute, La Jolla, CA, 92037, USA
| | - GS Robertson
- Department of Pharmacology, Dalhousie University, Halifax, NS, B3H 1X5, Canada; Department of Psychiatry, Dalhousie University, Halifax, NS, B3H 2E2, Canada
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Abstract
Accumulating evidence implicates a failure of myelin-reactive immune cells to undergo apoptosis in the pathological events contributing to multiple sclerosis (MS). We have recently demonstrated that members of the inhibitor of apoptosis (IAP) family of anti-apoptotic genes are elevated in peripheral blood immune cells (monocytes, T cells) of patients with aggressive forms of MS (secondary progressive) or those with relapsing-remitting MS suffering a disease replase. These findings suggest that the IAPs may be novel diagnostic markers for distinguishing subtypes of MS. Moreover, antisense-mediated knockdown of the IAP family member known as X-linked IAP (XIAP) reverses paralysis in an animal model of MS suggesting that treatments targeting XIAP, and perhaps other IAPs, may have utility in the treatment of MS.
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Affiliation(s)
- Andrea L O Hebb
- Department of Pharmacology, Dalhousie University, 5850 College Street, Halifax, NS B3H 1X5, Canada
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Zehntner SP, Bourbonnière L, Moore CS, Morris SJ, Methot D, St Jean M, Lacasse E, Hebb ALO, Robertson GS, Durkin J, Gillard JW, Owens T. X-linked inhibitor of apoptosis regulates T cell effector function. J Immunol 2008; 179:7553-60. [PMID: 18025200 DOI: 10.4049/jimmunol.179.11.7553] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
To understand how the balance between pro- and anti-apoptotic signals influences effector function in the immune system, we studied the X-linked inhibitor of apoptosis (XIAP), an endogenous regulator of cellular apoptosis. Real-time PCR showed increased XIAP expression in blood of mice with experimental autoimmune encephalomyelitis, correlating with disease severity. Daily administration (10 mg/kg/day i.p.) of a 19-mer antisense oligonucleotide specific for XIAP (ASO-XIAP) abolished disease-associated XIAP mRNA and protein expression, and given from day of onset, alleviated experimental autoimmune encephalomyelitis and prevented relapses. Prophylactic treatment also reduced XIAP expression and prevented disease. Random or 5-base mismatched ASO was not inhibitory, and ASO-XIAP did not affect T cell priming. In ASO-XIAP-treated animals, infiltrating cells and inflammatory foci were dramatically reduced within the CNS. Flow cytometry showed an 88-93% reduction in T cells. The proportion of TUNEL(+) apoptotic CD4(+) T cells in the CNS was increased from <1.6 to 26% in ASO-XIAP-treated mice, and the proportion of Annexin V-positive CD4(+) T cells in the CNS increased. Neurons and oligodendrocytes were not affected; neither did apoptosis increase in liver, where XIAP knockdown also occurred. ASO-XIAP increased susceptibility of T cells to activation-induced apoptosis in vitro. Our results identify XIAP as a critical controller of apoptotic susceptibility of effector T cell function.
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Affiliation(s)
- Simone P Zehntner
- Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Canada.
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Moore CS, Hebb ALO, Robertson GS. Inhibitor of apoptosis protein (IAP) profiling in experimental autoimmune encephalomyelitis (EAE) implicates increased XIAP in T lymphocytes. J Neuroimmunol 2007; 193:94-105. [PMID: 18055022 DOI: 10.1016/j.jneuroim.2007.10.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2007] [Revised: 10/19/2007] [Accepted: 10/24/2007] [Indexed: 11/16/2022]
Abstract
In multiple sclerosis (MS) and its widely accepted animal model, experimental autoimmune encephalomyelitis (EAE), the failure of autoreactive immune cells to undergo apoptosis is thought to contribute to CNS tissue damage and disease progression. Promoting apoptosis of myelin-reactive immune cells in diseases such as MS, may delay disease progression and decrease the frequency and severity of relapses. X-linked inhibitor of apoptosis (XIAP) is a potent anti-apoptotic protein that inhibits intrinsic, extrinsic, and c-Jun amino-terminal kinase mediated apoptosis and was the only member of the inhibitor of apoptosis (IAP) family upregulated in whole blood from EAE mice. Similar increases in XIAP were also observed in both peripheral and encephalitogenic T lymphocytes. Increased XIAP expression in T cells within areas of demyelination in the CNS suggests that XIAP may be enhancing cell survival and thereby contributing to disease pathology.
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Affiliation(s)
- Craig S Moore
- Department of Pharmacology, Dalhousie University, Faculty of Medicine, Sir Charles Tupper Building, 5850 College Street, Halifax NS Canada B3H 1X5
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Powell KJ, Hori SE, Leslie R, Andrieux A, Schellinck H, Thorne M, Robertson GS. Cognitive impairments in the STOP null mouse model of schizophrenia. Behav Neurosci 2007; 121:826-35. [PMID: 17907815 DOI: 10.1037/0735-7044.121.5.826] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cognitive dysfunction is a primary and persisting core deficit of schizophrenia that is marginally improved by antipsychotic treatment. Adult mice that lack the stable tubule-only polypeptide (STOP) have neurochemical and behavioral abnormalities that model some features of schizophrenia. Recognition and long-term memory in the STOP null mouse were tested with the novel object recognition task and an olfactory discrimination task, respectively. Researchers examined the brains from STOP null mice to determine whether differences in task performance were associated with alterations in brain morphology. STOP null mice displayed deficits in both recognition and long-term memory. These behavioral deficits were accompanied by a massive enlargement of the cerebral ventricular system as well as by reductions in volume of cortical and diencephalic structures. In addition to deficits in recognition and long-term memory, STOP null mice displayed exaggerated neuroanatomical deficits somewhat reminiscent of those observed among individuals with schizophrenia.
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Affiliation(s)
- Kelly J Powell
- Department of Pharmacology, Dalhousie University, Halifax, NS, Canada
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Soundararajan R, Wishart AD, Rupasinghe HPV, Arcellana-Panlilio M, Nelson CM, Mayne M, Robertson GS. Quercetin 3-glucoside protects neuroblastoma (SH-SY5Y) cells in vitro against oxidative damage by inducing sterol regulatory element-binding protein-2-mediated cholesterol biosynthesis. J Biol Chem 2007; 283:2231-45. [PMID: 18032389 DOI: 10.1074/jbc.m703583200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The flavonoid quercetin 3-glucoside (Q3G) protected SH-SY5Y, HEK293, and MCF-7 cells against hydrogen peroxide-induced oxidative stress. cDNA microarray studies suggested that Q3G-pretreated cells subjected to oxidative stress up-regulate the expression of genes associated with lipid and cholesterol biosynthesis. Q3G pretreatment elevated both the expression and activation of sterol regulatory element-binding protein-2 (SREBP-2) only in SH-SY5Y cells subjected to oxidative stress. Inhibition of SREBP-2 expression by small interfering RNA or small molecule inhibitors of 2,3-oxidosqualene:lanosterol cyclase or HMG-CoA reductase blocked Q3G-mediated cytoprotection in SH-SY5Y cells. By contrast, Q3G did not protect either HEK293 or MCF-7 cells via this signaling pathway. Moreover, the addition of isopentenyl pyrophosphate rescued SH-SY5Y cells from the inhibitory effect of HMG-CoA reductase inhibition. Last, Q3G pretreatment enhanced the incorporation of [(14)C]acetate into [(14)C]cholesterol in SH-SY5Y cells under oxidative stress. Taken together, these studies suggest a novel mechanism for flavonoid-induced cytoprotection in SH-SY5Y cells involving SREBP-2-mediated sterol synthesis that decreases lipid peroxidation by maintaining membrane integrity in the presence of oxidative stress.
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Affiliation(s)
- Ramani Soundararajan
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada
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Reddy VM, Sutton CD, Bloxham L, Garcea G, Ubhi SS, Robertson GS. Laparoscopic repair of direct inguinal hernia: a new technique that reduces the development of postoperative seroma. Hernia 2007; 11:393-6. [PMID: 17541495 DOI: 10.1007/s10029-007-0233-4] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Accepted: 04/05/2007] [Indexed: 11/29/2022]
Abstract
BACKGROUND Seroma are common early postoperative complications encountered in laparoscopic inguinal hernia repair. Previous anecdotal evidence from our surgical practice suggested a lower incidence of postoperative seroma formation with direct hernia repairs when the lax transversalis fascia (TF) is inverted by tacking to the pubic ramus. We undertook a study to investigate whether TF inversion in this way reduces the incidence of postoperative seroma. METHOD A total of 216 patients undergoing transabdominal preperitoneal (TAPP) laparoscopic inguinal hernia repairs from August 2003 to December 2005 were included in this prospective non-randomised controlled study. Surgeon 1 would routinely invert the TF whereas surgeon 2 would not. At follow-up the presence of postoperative seroma and pain was recorded. RESULTS Mann-Whitney U test demonstrated no significant difference in terms of age, sex and time to follow-up between the surgeons' patient groups (P > 0.05), and Chi-square test demonstrated significantly that inversion of the TF is associated with a lower incidence of postoperative seroma (P < 0.05). There was no significant difference in terms of postoperative pain at follow-up. CONCLUSION Inversion of the TF is associated with a statistically lower incidence of postoperative seroma, without increasing postoperative pain despite the use of one or two additional tacks.
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Affiliation(s)
- V M Reddy
- Department of General Surgery, Leicester Royal Infirmary, Infirmary Square, Leicester, LE1 5WW, UK.
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