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Ali I, Van Eetveldt A, Van Elzen R, Kalathil Raju T, Van Der Veken P, Lambeir A, Dedeurwaerdere S. Spatiotemporal expression and inhibition of prolyl oligopeptidase contradict its involvement in key pathologic mechanisms of kainic acid-induced temporal lobe epilepsy in rats. Epilepsia Open 2019; 4:92-101. [PMID: 30868119 PMCID: PMC6398098 DOI: 10.1002/epi4.12293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 12/04/2018] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE Prolyl oligopeptidase (PREP) has been implicated in neuroinflammatory processes and neuroplasticity and has been suggested as a target for the treatment of neurodegenerative disease. The aim of this investigation was to explore the involvement of PREP in the neuropathologic mechanisms relevant to temporal lobe epilepsy (TLE) using a PREP inhibitor in a well-established rat model. METHODS PREP activity and expression was studied in Sprague-Dawley rats 2 and 12 weeks following kainic acid-induced status epilepticus (KASE). Continuous video-electroencephalography monitoring was performed for 2 weeks in the 12-week cohort to identify a relationship of PREP expression/activity with epileptic seizures. In addition, the animals included in the 2-week time point were treated with a specific inhibitor of PREP, KYP-2047, or saline continuously, starting immediately after SE. PREP activity and its expression were analyzed in rat brain by using enzyme kinetics and western blot. In addition, markers for microglial activation, astrogliosis, cell loss, and cell proliferation were evaluated. RESULTS Enzymatic activity of PREP was unchanged following induction of SE after 2 and 12 weeks in rats. PREP activity in epileptic rats did not relate to the number of seizures/day at the 12-week time point. Moreover, continuous inhibition of PREP for 2 weeks after KASE did not alter the SE-mediated neuroinflammatory response, cell loss, or cell proliferation in the hippocampal subgranule zone measured at the 2-week time point. SIGNIFICANCE PREP inhibition does not affect key pathologic mechanisms, including activation of glial cells, cell loss, and neural progenitor cell proliferation, in this KASE model of TLE. The results do not support a direct role of PREP in seizure burden during the chronic epilepsy period in this model.
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Affiliation(s)
- Idrish Ali
- Department of Translational NeurosciencesUniversity of AntwerpWilrijkBelgium
- Present address:
Department of MedicineUniversity of MelbourneMelbourneAustralia
| | | | - Roos Van Elzen
- Laboratory of Medical BiochemistryUniversity of AntwerpWilrijkBelgium
| | - Tom Kalathil Raju
- Laboratory of Medical BiochemistryUniversity of AntwerpWilrijkBelgium
| | | | | | - Stefanie Dedeurwaerdere
- Laboratory of Experimental Hematology, VaxinfectioUniversity of AntwerpAntwerpBelgium
- Present address:
UCB PharmaBraine‐l'AlleudBelgium
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Amhaoul H, Ali I, Mola M, Van Eetveldt A, Szewczyk K, Missault S, Bielen K, Kumar-Singh S, Rech J, Lord B, Ceusters M, Bhattacharya A, Dedeurwaerdere S. P2X7 receptor antagonism reduces the severity of spontaneous seizures in a chronic model of temporal lobe epilepsy. Neuropharmacology 2016; 105:175-185. [PMID: 26775823 DOI: 10.1016/j.neuropharm.2016.01.018] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 01/05/2016] [Accepted: 01/12/2016] [Indexed: 11/29/2022]
Abstract
BACKGROUND The available pharmacotherapy for patients with epilepsy primarily address the symptoms and are ineffective in about 40% of patients. Brain inflammation gained support as potential target for developing new therapies, especially the P2X7 receptor (P2X7R), involved in processing of IL-1β, might be an interesting candidate. This study was designed to investigate the effect of a novel P2X7R antagonist on the severity and on the number of chronic spontaneous recurrent seizures (SRS), which was unexplored until now. METHODS After one-week of vehicle treatment (20% HP-β-cyclodextrin), JNJ-42253432 was administered subcutaneously for another week under continuous video-electroencephalography monitoring (n = 17) in Sprague Dawley rats 3 months after kainic acid-induced status epilepticus. The proportion of different seizure classes, as well as the number of SRS/day were calculated for the vehicle and treatment period. In addition, post-mortem microglial activation and astrogliosis were assessed. RESULTS A significant decrease of the proportion of type 4-5 SRS (p < 0.05), while an increase of type 1-3 was demonstrated (p < 0.05) from the vehicle to the treatment period. There was no effect of the P2X7R antagonist on the number of SRS/day or the glial markers. CONCLUSIONS The P2X7R antagonist gave rise to a less severe profile of the chronic seizure burden without suppressing the SRS frequency. More studies are needed to unravel the underlying mechanisms of the beneficial effect on seizure severity and whether the administration of the compound during early epileptogenesis could induce long-term disease-modifying effects.
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Affiliation(s)
- Halima Amhaoul
- Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium
| | - Idrish Ali
- Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium
| | - Marco Mola
- Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium
| | - Annemie Van Eetveldt
- Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium
| | - Krystyna Szewczyk
- Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium
| | - Stephan Missault
- Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium
| | - Kenny Bielen
- Laboratory of Cell Biology and Histology, University of Antwerp, Antwerp, Belgium
| | - Samir Kumar-Singh
- Department of Translational Neurosciences, University of Antwerp, Wilrijk, Belgium; Laboratory of Cell Biology and Histology, University of Antwerp, Antwerp, Belgium
| | - Jason Rech
- Neuroscience Therapeutic Area, Janssen Research & Development, San Diego, USA
| | - Brian Lord
- Neuroscience Therapeutic Area, Janssen Research & Development, San Diego, USA
| | - Marc Ceusters
- Neuroscience Therapeutic Area, Janssen Research & Development, Beerse, Belgium
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Amhaoul H, Hamaide J, Bertoglio D, Reichel SN, Verhaeghe J, Geerts E, Van Dam D, De Deyn PP, Kumar-Singh S, Katsifis A, Van Der Linden A, Staelens S, Dedeurwaerdere S. Brain inflammation in a chronic epilepsy model: Evolving pattern of the translocator protein during epileptogenesis. Neurobiol Dis 2015; 82:526-539. [PMID: 26388398 DOI: 10.1016/j.nbd.2015.09.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 08/24/2015] [Accepted: 09/16/2015] [Indexed: 11/27/2022] Open
Abstract
AIMS A hallmark in the neuropathology of temporal lobe epilepsy is brain inflammation which has been suggested as both a biomarker and a new mechanistic target for treatments. The translocator protein (TSPO), due to its high upregulation under neuroinflammatory conditions and the availability of selective PET tracers, is a candidate target. An important step to exploit this target is a thorough characterisation of the spatiotemporal profile of TSPO during epileptogenesis. METHODS TSPO expression, microglial activation, astrocyte reactivity and cell loss in several brain regions were evaluated at five time points during epileptogenesis, including the chronic epilepsy phase in the kainic acid-induced status epilepticus (KASE) model (n = 52) and control Wistar Han rats (n = 33). Seizure burden was also determined in the chronic phase. Furthermore, ¹⁸F-PBR111 PET/MRI scans were acquired longitudinally in an additional four KASE animals. RESULTS TSPO expression measured with in vitro and in vivo techniques was significantly increased at each time point and peaked two weeks post-SE in the limbic system. A prominent association between TSPO expression and activated microglia (p < 0.001; r = 0.7), as well as cell loss (p < 0.001; r = -0.8) could be demonstrated. There was a significant positive correlation between spontaneous seizures and TSPO upregulation in several brain regions with increased TSPO expression. CONCLUSIONS TSPO expression was dynamically upregulated during epileptogenesis, persisted in the chronic phase and correlated with microglia activation rather than reactive astrocytes. TSPO expression was correlating with spontaneous seizures and its high expression during the latent phase might possibly suggest being an important switching point in disease ontogenesis which could be further investigated by PET imaging.
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Affiliation(s)
- Halima Amhaoul
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | - Julie Hamaide
- Department of Translational Neurosciences, University of Antwerp, Belgium; Bio-Imaging Lab, University of Antwerp, Belgium
| | - Daniele Bertoglio
- Department of Translational Neurosciences, University of Antwerp, Belgium
| | | | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp, University of Antwerp, Belgium
| | - Elly Geerts
- Laboratory of Neurochemistry and Behaviour, University of Antwerp, Belgium
| | - Debby Van Dam
- Laboratory of Neurochemistry and Behaviour, University of Antwerp, Belgium
| | - Peter Paul De Deyn
- Laboratory of Neurochemistry and Behaviour, University of Antwerp, Belgium; Department of Neurology and Memory Clinic, Hospital Network Antwerp (ZNA) Middelheim and Hoge Beuken, Belgium; Department of Neurology and Alzheimer Research Center, University of Groningen and University Medical Center Groningen (UMCG), The Netherlands
| | - Samir Kumar-Singh
- Laboratory of Cell Biology & Histology, University of Antwerp, Belgium
| | - Andrew Katsifis
- Department of PET and Nuclear Medicine, Royal Prince Alfred Hospital, Australia
| | | | - Steven Staelens
- Molecular Imaging Center Antwerp, University of Antwerp, Belgium
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Elms J, Powell KL, van Raay L, Dedeurwaerdere S, O’Brien TJ, Morris MJ. Long-term valproate treatment increases brain neuropeptide Y expression and decreases seizure expression in a genetic rat model of absence epilepsy. PLoS One 2013; 8:e73505. [PMID: 24039965 PMCID: PMC3767750 DOI: 10.1371/journal.pone.0073505] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 07/23/2013] [Indexed: 11/19/2022] Open
Abstract
The mechanisms by which valproate, one of the most widely prescribed anti-epileptic drugs, suppresses seizures have not been fully elucidated but may involve up-regulation of neuropeptide Y (NPY). We investigated the effects of valproate treatment in Genetic Absence Epilepsy Rats from Strasbourg (GAERS) on brain NPY mRNA expression and seizure control. GAERS were administered either valproate (42 mg.kg−1 hr−1) or saline continuously for 5 days. Electroencephalograms were recorded for 24 hrs on treatment days 1, 3 and 5 and the percentage of time spent in seizure activity was analysed. NPY mRNA expression was measured in different brain regions using qPCR. Valproate treatment suppressed seizures by 80% in GAERS (p<0.05) and increased NPY mRNA expression in the thalamus (p<0.05) compared to saline treatment. These results demonstrate that long-term valproate treatment results in an upregulation of thalamic expression of NPY implicating this as a potential contributor to the mechanism by which valproate suppresses absence seizures.
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Affiliation(s)
- Johanna Elms
- Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
- The Department of Medicine, The University of Melbourne, Royal Melbourne Hospital, Melbourne, Australia
| | - Kim L. Powell
- The Department of Medicine, The University of Melbourne, Royal Melbourne Hospital, Melbourne, Australia
| | - Leena van Raay
- The Department of Medicine, The University of Melbourne, Royal Melbourne Hospital, Melbourne, Australia
| | | | - Terence J. O’Brien
- The Department of Medicine, The University of Melbourne, Royal Melbourne Hospital, Melbourne, Australia
| | - Margaret J. Morris
- Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
- * E-mail:
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Shultz SR, Cardamone L, Liu YR, Hogan RE, Maccotta L, Wright DK, Zheng P, Koe A, Gregoire MC, Williams JP, Hicks RJ, Jones NC, Myers DE, O'Brien TJ, Bouilleret V. Can structural or functional changes following traumatic brain injury in the rat predict epileptic outcome? Epilepsia 2013; 54:1240-50. [PMID: 23718645 DOI: 10.1111/epi.12223] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/15/2013] [Indexed: 02/06/2023]
Abstract
PURPOSE Posttraumatic epilepsy (PTE) occurs in a proportion of traumatic brain injury (TBI) cases, significantly compounding the disability, and risk of injury and death for sufferers. To date, predictive biomarkers for PTE have not been identified. This study used the lateral fluid percussion injury (LFPI) rat model of TBI to investigate whether structural, functional, and behavioral changes post-TBI relate to the later development of PTE. METHODS Adult male Wistar rats underwent LFPI or sham injury. Serial magnetic resonance (MR) and positron emission tomography (PET) imaging, and behavioral analyses were performed over 6 months postinjury. Rats were then implanted with recording electrodes and monitored for two consecutive weeks using video-electroencephalography (EEG) to assess for PTE. Of the LFPI rats, 52% (n = 12) displayed spontaneous recurring seizures and/or epileptic discharges on the video-EEG recordings. KEY FINDINGS MRI volumetric and signal analysis of changes in cortex, hippocampus, thalamus, and amygdala, (18) F-fluorodeoxyglucose (FDG)-PET analysis of metabolic function, and behavioral analysis of cognitive and emotional changes, at 1 week, and 1, 3, and 6 months post-LFPI, all failed to identify significant differences on univariate analysis between the epileptic and nonepileptic groups. However, hippocampal surface shape analysis using large-deformation high-dimensional mapping identified significant changes in the ipsilateral hippocampus at 1 week postinjury relative to baseline that differed between rats that would go onto become epileptic versus those who did not. Furthermore, a multivariate logistic regression model that incorporated the 1 week, and 1 and 3 month (18) F-FDG PET parameters from the ipsilateral hippocampus was able to correctly predict the epileptic outcome in all of the LFPI cases. As such, these subtle changes in the ipsilateral hippocampus at acute phases after LFPI may be related to PTE and require further examination. SIGNIFICANCE These findings suggest that PTE may be independent of major structural, functional, and behavioral changes induced by TBI, and suggest that more subtle abnormalities are likely involved. However, there are limitations associated with studying acquired epilepsies in animal models that must be considered when interpreting these results, in particular the failure to detect differences between the groups may be related to the limitations of properly identifying/separating the epileptic and nonepileptic animals into the correct group.
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Affiliation(s)
- Sandy R Shultz
- Department of Medicine, RMH, University of Melbourne, Parkville, Victoria, Australia.
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Dedeurwaerdere S, Fang K, Chow M, Shen YT, Noordman I, van Raay L, Faggian N, Porritt M, Egan G, O'Brien T. Manganese-enhanced MRI reflects seizure outcome in a model for mesial temporal lobe epilepsy. Neuroimage 2013; 68:30-8. [DOI: 10.1016/j.neuroimage.2012.11.054] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 11/23/2012] [Indexed: 10/27/2022] Open
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Lohman RJ, Cotterell AJ, Barry GD, Liu L, Suen JY, Vesey DA, Fairlie DP. An antagonist of human protease activated receptor-2 attenuates PAR2 signaling, macrophage activation, mast cell degranulation, and collagen-induced arthritis in rats. FASEB J 2012; 26:2877-87. [PMID: 22467762 DOI: 10.1096/fj.11-201004] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Multiple serine proteases exert proinflammatory actions by signaling through protease-activated receptor-2 (PAR2) on the cell surface. Although inhibitors of individual proteases are anti-inflammatory, we sought to discover whether the first potent antagonist of their common target PAR2 might be beneficial in treating chronic arthritis-like inflammatory disease. Using a fluorescence assay, a novel compound, GB88, was shown to antagonize PAR2-induced intracellular Ca(2+) release in human monocyte-derived macrophages, being 1000 times more potent than a control compound, ENMD-1068 (IC(50) 1.6 ± 0.5 μM vs. 1.2 ± 0.4 mM, respectively). In Wistar rats, GB88 was orally bioavailable (F=55%, T(max) 4 h, C(max) 1.7 μM, 10 mg/kg). GB88 inhibited the acute paw edema induced in Wistar rats by intraplantar λ-carrageenan or PAR2 agonists 2-furoyl-LIGRLO-NH(2) or mast cell β-tryptase, without inhibiting proteolytic activity of tryptase in vitro. In the chronic collagen-induced model of arthritis in rats, GB88 (10 mg/kg) was disease modifying and ameliorated pathological and histopathological changes (edema, pannus formation, synovial hyperplasia, collagen degradation, macrophage invasion, mast cell degranulation) compared to untreated arthritic controls. The results suggest that an orally active PAR2 antagonist is effective in treating chronic arthritis in rats through inhibiting macrophage infiltration, mast cell degranulation, and β-tryptase-PAR2 signaling in joint inflammation.
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Affiliation(s)
- Rink-Jan Lohman
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
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Bouilleret V, Cardamone L, Liu C, Koe AS, Fang K, Williams JP, Myers DE, O'Brien TJ, Jones NC. Confounding neurodegenerative effects of manganese for in vivo MR imaging in rat models of brain insults. J Magn Reson Imaging 2011; 34:774-84. [DOI: 10.1002/jmri.22669] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 05/05/2011] [Indexed: 11/11/2022] Open
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Dedeurwaerdere S, van Raay L, Morris M, Reed R, Hogan R, O’Brien T. Fluctuating and constant valproate administration gives equivalent seizure control in rats with genetic and acquired epilepsy. Seizure 2011; 20:72-9. [DOI: 10.1016/j.seizure.2010.10.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 10/04/2010] [Accepted: 10/15/2010] [Indexed: 11/28/2022] Open
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Bouilleret V, Cardamone L, Liu YR, Fang K, Myers DE, O'Brien TJ. Progressive brain changes on serial manganese-enhanced MRI following traumatic brain injury in the rat. J Neurotrauma 2010; 26:1999-2013. [PMID: 19604101 DOI: 10.1089/neu.2009.0943] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Traumatic brain injury (TBI) has a high incidence of long-term morbidity. Manganese-enhanced MRI (MEMRI) provides high contrast structural and functional detail of the brain in-vivo. The study utilized serial MEMRI scanning in the fluid percussion injury (FPI) rat's model to assess long-term changes in the brain following TBI. Rats underwent a left-sided craniotomy and a 3.5 atmosphere FPI pulse (n = 23) or sham procedure (n = 22). MEMRI acquisition was performed at baseline, 1 day, 1 month, and 6 months after FPI. Volume changes and MnCl(2) enhancement were measured blindly using region-of-interest analysis and the results analyzed with repeated measures MANOVA. Compared to the shams, FPI animals showed a progressive decrease in brain volume from 1 (right, p = 0.02; left, p = 0.008) to 6 months (right, p = 0.04; left, p = 0.006), with progression over time (F = 7.16, p = 0.00018). Similar changes were found in the cortex and the hippocampus. Conversely, the ventricular volume was increased at 1 (p = 0.02) and 6 months (p = 0.003), with progression over time (F = 7.27, p = 0.0001). There were no differences in thalamic or amygdalae volumes. The severity of the early neuromotor deficits and the T2 signal intensity of the subacute focal lesion were highly predictive of the severity of the long-term hippocampal decrease, and the former was also associated with the degree of neuronal sprouting. Differential MnCl(2) enhancement occurred only in the dentate gyrus at 1 month on the side of trauma (p = 0.04). Progressive functional and structural changes occur in specific brain regions post-FPI. The severity of the neuromotor deficit and focal signal changes on MRI subacutely post-injury are predictive of severity of these long-term neurodegenerative changes.
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Affiliation(s)
- Viviane Bouilleret
- Department of Medicine (RMH), University of Melbourne, Victoria, Australia
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