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Voskobiynyk Y, Li Z, Cochran JN, Davis MN, Carullo NVN, Creed RB, Buckingham SC, Hall AM, Wilson SM, Roberson ED. Excitoprotective effects of conditional tau reduction in excitatory neurons and in adulthood. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.14.594246. [PMID: 38798487 PMCID: PMC11118377 DOI: 10.1101/2024.05.14.594246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Tau reduction is a promising therapeutic strategy for Alzheimer's disease. In numerous models, tau reduction via genetic knockout is beneficial, at least in part due to protection against hyperexcitability and seizures, but the underlying mechanisms are unclear. Here we describe the generation and initial study of a new conditional Tau flox model to address these mechanisms. Given the protective effects of tau reduction against hyperexcitability, we compared the effects of selective tau reduction in excitatory or inhibitory neurons. Tau reduction in excitatory neurons mimicked the protective effects of global tau reduction, while tau reduction in inhibitory neurons had the opposite effect and increased seizure susceptibility. Since most prior studies used knockout mice lacking tau throughout development, we crossed Tau flox mice with inducible Cre mice and found beneficial effects of tau reduction in adulthood. Our findings support the effectiveness of tau reduction in adulthood and indicate that excitatory neurons may be a key site for its excitoprotective effects. SUMMARY A new conditional tau knockout model was generated to study the protective effects of tau reduction against hyperexcitability. Conditional tau reduction in excitatory, but not inhibitory, neurons was excitoprotective, and induced tau reduction in adulthood was excitoprotective without adverse effects.
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Vicente M, Addo-Osafo K, Vossel K. Latest advances in mechanisms of epileptic activity in Alzheimer's disease and dementia with Lewy Bodies. Front Neurol 2024; 15:1277613. [PMID: 38390593 PMCID: PMC10882721 DOI: 10.3389/fneur.2024.1277613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 01/12/2024] [Indexed: 02/24/2024] Open
Abstract
Alzheimer's disease (AD) and dementia with Lewy bodies (DLB) stand as the prevailing sources of neurodegenerative dementia, impacting over 55 million individuals across the globe. Patients with AD and DLB exhibit a higher prevalence of epileptic activity compared to those with other forms of dementia. Seizures can accompany AD and DLB in early stages, and the associated epileptic activity can contribute to cognitive symptoms and exacerbate cognitive decline. Aberrant neuronal activity in AD and DLB may be caused by several mechanisms that are not yet understood. Hyperexcitability could be a biomarker for early detection of AD or DLB before the onset of dementia. In this review, we compare and contrast mechanisms of network hyperexcitability in AD and DLB. We examine the contributions of genetic risk factors, Ca2+ dysregulation, glutamate, AMPA and NMDA receptors, mTOR, pathological amyloid beta, tau and α-synuclein, altered microglial and astrocytic activity, and impaired inhibitory interneuron function. By gaining a deeper understanding of the molecular mechanisms that cause neuronal hyperexcitability, we might uncover therapeutic approaches to effectively ease symptoms and slow down the advancement of AD and DLB.
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Affiliation(s)
- Mariane Vicente
- Mary S. Easton Center for Alzheimer's Research and Care, Department of Neurology, David Geffen School of Medicine at University of California, Los Angeles, CA, United States
| | - Kwaku Addo-Osafo
- Mary S. Easton Center for Alzheimer's Research and Care, Department of Neurology, David Geffen School of Medicine at University of California, Los Angeles, CA, United States
| | - Keith Vossel
- Mary S. Easton Center for Alzheimer's Research and Care, Department of Neurology, David Geffen School of Medicine at University of California, Los Angeles, CA, United States
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Putra M, Vasanthi SS, Rao NS, Meyer C, Van Otterloo M, Thangi L, Thedens DR, Kannurpatti SS, Thippeswamy T. Inhibiting Inducible Nitric Oxide Synthase with 1400W Reduces Soman (GD)-Induced Ferroptosis in Long-Term Epilepsy-Associated Neuropathology: Structural and Functional Magnetic Resonance Imaging Correlations with Neurobehavior and Brain Pathology. J Pharmacol Exp Ther 2024; 388:724-738. [PMID: 38129129 PMCID: PMC10801728 DOI: 10.1124/jpet.123.001929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 12/23/2023] Open
Abstract
Organophosphate (OP) nerve agent (OPNA) intoxication leads to long-term brain dysfunctions. The ineffectiveness of current treatments for OPNA intoxication prompts a quest for the investigation of the mechanism and an alternative effective therapeutic approach. Our previous studies on 1400W, a highly selective inducible nitric oxide synthase (iNOS) inhibitor, showed improvement in epilepsy and seizure-induced brain pathology in rat models of kainate and OP intoxication. In this study, magnetic resonance imaging (MRI) modalities, behavioral outcomes, and biomarkers were comprehensively investigated for brain abnormalities following soman (GD) intoxication in a rat model. T1 and T2 MRI robustly identified pathologic microchanges in brain structures associated with GD toxicity, and 1400W suppressed those aberrant alterations. Moreover, functional network reduction was evident in the cortex, hippocampus, and thalamus after GD exposure, and 1400W rescued the losses except in the thalamus. Behavioral tests showed protection by 1400W against GD-induced memory dysfunction, which also correlated with the extent of brain pathology observed in structural and functional MRIs. GD exposure upregulated iron-laden glial cells and ferritin levels in the brain and serum, 1400W decreased ferritin levels in the epileptic foci in the brain but not in the serum. The levels of brain ferritin also correlated with MRI parameters. Further, 1400W mitigated the overproduction of nitroxidative markers after GD exposure. Overall, this study provides direct evidence for the relationships of structural and functional MRI modalities with behavioral and molecular abnormalities following GD exposure and the neuroprotective effect of an iNOS inhibitor, 1400W. SIGNIFICANT STATEMENT: Our studies demonstrate the MRI microchanges in the brain following GD toxicity, which strongly correlate with neurobehavioral performances and iron homeostasis. The inhibition of iNOS with 1400W mitigates GD-induced cognitive decline, iron dysregulation, and aberrant brain MRI findings.
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Affiliation(s)
- Marson Putra
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa (M.P., S.S.V., N.S.R., C.M., M.V.O., L.T., T.T.); Department of Radiology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa (D.R.T.); and Department of Radiology, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, New Jersey (S.S.K.)
| | - Suraj S Vasanthi
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa (M.P., S.S.V., N.S.R., C.M., M.V.O., L.T., T.T.); Department of Radiology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa (D.R.T.); and Department of Radiology, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, New Jersey (S.S.K.)
| | - Nikhil S Rao
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa (M.P., S.S.V., N.S.R., C.M., M.V.O., L.T., T.T.); Department of Radiology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa (D.R.T.); and Department of Radiology, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, New Jersey (S.S.K.)
| | - Christina Meyer
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa (M.P., S.S.V., N.S.R., C.M., M.V.O., L.T., T.T.); Department of Radiology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa (D.R.T.); and Department of Radiology, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, New Jersey (S.S.K.)
| | - Madison Van Otterloo
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa (M.P., S.S.V., N.S.R., C.M., M.V.O., L.T., T.T.); Department of Radiology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa (D.R.T.); and Department of Radiology, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, New Jersey (S.S.K.)
| | - Lal Thangi
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa (M.P., S.S.V., N.S.R., C.M., M.V.O., L.T., T.T.); Department of Radiology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa (D.R.T.); and Department of Radiology, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, New Jersey (S.S.K.)
| | - Daniel R Thedens
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa (M.P., S.S.V., N.S.R., C.M., M.V.O., L.T., T.T.); Department of Radiology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa (D.R.T.); and Department of Radiology, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, New Jersey (S.S.K.)
| | - Sridhar S Kannurpatti
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa (M.P., S.S.V., N.S.R., C.M., M.V.O., L.T., T.T.); Department of Radiology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa (D.R.T.); and Department of Radiology, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, New Jersey (S.S.K.)
| | - Thimmasettappa Thippeswamy
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, Iowa (M.P., S.S.V., N.S.R., C.M., M.V.O., L.T., T.T.); Department of Radiology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa (D.R.T.); and Department of Radiology, Rutgers Biomedical and Health Sciences, New Jersey Medical School, Newark, New Jersey (S.S.K.)
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4
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Roth JR, Rush T, Thompson SJ, Aldaher AR, Dunn TB, Mesina JS, Cochran JN, Boyle NR, Dean HB, Yang Z, Pathak V, Ruiz P, Wu M, Day JJ, Bostwick JR, Suto MJ, Augelli-Szafran CE, Roberson ED. Development of small-molecule Tau-SH3 interaction inhibitors that prevent amyloid-β toxicity and network hyperexcitability. Neurotherapeutics 2024; 21:e00291. [PMID: 38241154 PMCID: PMC10903085 DOI: 10.1016/j.neurot.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 10/24/2023] [Indexed: 01/21/2024] Open
Abstract
Alzheimer's disease (AD) is the leading cause of dementia and lacks highly effective treatments. Tau-based therapies hold promise. Tau reduction prevents amyloid-β-induced dysfunction in preclinical models of AD and also prevents amyloid-β-independent dysfunction in diverse disease models, especially those with network hyperexcitability, suggesting that strategies exploiting the mechanisms underlying Tau reduction may extend beyond AD. Tau binds several SH3 domain-containing proteins implicated in AD via its central proline-rich domain. We previously used a peptide inhibitor to demonstrate that blocking Tau interactions with SH3 domain-containing proteins ameliorates amyloid-β-induced dysfunction. Here, we identify a top hit from high-throughput screening for small molecules that inhibit Tau-FynSH3 interactions and describe its optimization with medicinal chemistry. The resulting lead compound is a potent cell-permeable Tau-SH3 interaction inhibitor that binds Tau and prevents amyloid-β-induced dysfunction, including network hyperexcitability. These data support the potential of using small molecule Tau-SH3 interaction inhibitors as a novel therapeutic approach to AD.
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Affiliation(s)
- Jonathan R Roth
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Travis Rush
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Samantha J Thompson
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Adam R Aldaher
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Trae B Dunn
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jacob S Mesina
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - J Nicholas Cochran
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Nicholas R Boyle
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hunter B Dean
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Zhengrong Yang
- Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Vibha Pathak
- Chemistry Department, Southern Research, Birmingham, AL, USA
| | - Pedro Ruiz
- Chemistry Department, Southern Research, Birmingham, AL, USA
| | - Mousheng Wu
- Chemistry Department, Southern Research, Birmingham, AL, USA
| | - Jeremy J Day
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Mark J Suto
- Chemistry Department, Southern Research, Birmingham, AL, USA
| | | | - Erik D Roberson
- Center for Neurodegeneration and Experimental Therapeutics, Alzheimer's Disease Center, Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA.
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Meyer C, Grego E, S. Vasanthi S, Rao NS, Massey N, Holtkamp C, Huss J, Showman L, Narasimhan B, Thippeswamy T. The NADPH Oxidase Inhibitor, Mitoapocynin, Mitigates DFP-Induced Reactive Astrogliosis in a Rat Model of Organophosphate Neurotoxicity. Antioxidants (Basel) 2023; 12:2061. [PMID: 38136181 PMCID: PMC10740988 DOI: 10.3390/antiox12122061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 11/22/2023] [Accepted: 11/28/2023] [Indexed: 12/24/2023] Open
Abstract
NADPH oxidase (NOX) is a primary mediator of superoxides, which promote oxidative stress, neurodegeneration, and neuroinflammation after diisopropylfluorophosphate (DFP) intoxication. Although orally administered mitoapocynin (MPO, 10 mg/kg), a mitochondrial-targeted NOX inhibitor, reduced oxidative stress and proinflammatory cytokines in the periphery, its efficacy in the brain regions of DFP-exposed rats was limited. In this study, we encapsulated MPO in polyanhydride nanoparticles (NPs) based on 1,6-bis(p-carboxyphenoxy) hexane (CPH) and sebacic anhydride (SA) for enhanced drug delivery to the brain and compared with a high oral dose of MPO (30 mg/kg). NOX2 (GP91phox) regulation and microglial (IBA1) morphology were analyzed to determine the efficacy of MPO-NP vs. MPO-oral in an 8-day study in the rat DFP model. Compared to the control, DFP-exposed animals exhibited significant upregulation of NOX2 and a reduced length and number of microglial processes, indicative of reactive microglia. Neither MPO treatment attenuated the DFP effect. Neurodegeneration (FJB+NeuN) was significantly greater in DFP-exposed groups regardless of treatment. Interestingly, neuronal loss in DFP+MPO-treated animals was not significantly different from the control. MPO-oral rescued inhibitory neuronal loss in the CA1 region of the hippocampus. Notably, MPO-NP and MPO-oral significantly reduced astrogliosis (absolute GFAP counts) and reactive gliosis (C3+GFAP). An analysis of inwardly rectifying potassium channels (Kir4.1) in astroglia revealed a significant reduction in the brain regions of the DFP+VEH group, but MPO had no effect. Overall, both NP-encapsulated and orally administered MPO had similar effects. Our findings demonstrate that MPO effectively mitigates DFP-induced reactive astrogliosis in several key brain regions and protects neurons in CA1, which may have long-term beneficial effects on spontaneous seizures and behavioral comorbidities. Long-term telemetry and behavioral studies and a different dosing regimen of MPO are required to understand its therapeutic potential.
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Affiliation(s)
- Christina Meyer
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50010, USA; (C.M.); (S.S.V.); (N.S.R.); (N.M.); (C.H.); (J.H.)
| | - Elizabeth Grego
- Department of Chemical and Biological Engineering, Nanovaccine Institute, Iowa State University, Ames, IA 50011, USA; (E.G.); (B.N.)
| | - Suraj S. Vasanthi
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50010, USA; (C.M.); (S.S.V.); (N.S.R.); (N.M.); (C.H.); (J.H.)
| | - Nikhil S. Rao
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50010, USA; (C.M.); (S.S.V.); (N.S.R.); (N.M.); (C.H.); (J.H.)
| | - Nyzil Massey
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50010, USA; (C.M.); (S.S.V.); (N.S.R.); (N.M.); (C.H.); (J.H.)
| | - Claire Holtkamp
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50010, USA; (C.M.); (S.S.V.); (N.S.R.); (N.M.); (C.H.); (J.H.)
| | - Joselyn Huss
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50010, USA; (C.M.); (S.S.V.); (N.S.R.); (N.M.); (C.H.); (J.H.)
| | - Lucas Showman
- W.M. Keck Metabolomics Research Laboratory, Iowa State University, Ames, IA 50011, USA;
| | - Balaji Narasimhan
- Department of Chemical and Biological Engineering, Nanovaccine Institute, Iowa State University, Ames, IA 50011, USA; (E.G.); (B.N.)
| | - Thimmasettappa Thippeswamy
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50010, USA; (C.M.); (S.S.V.); (N.S.R.); (N.M.); (C.H.); (J.H.)
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Rao NS, Putra M, Meyer C, Almanza A, Thippeswamy T. The effects of Src tyrosine kinase inhibitor, saracatinib, on the markers of epileptogenesis in a mixed-sex cohort of adult rats in the kainic acid model of epilepsy. Front Mol Neurosci 2023; 16:1294514. [PMID: 38025259 PMCID: PMC10665569 DOI: 10.3389/fnmol.2023.1294514] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 10/25/2023] [Indexed: 12/01/2023] Open
Abstract
Neurodegeneration and neuroinflammation are key processes of epileptogenesis in temporal lobe epilepsy (TLE). A considerable number (∼30%) of patients with epilepsy are resistant to currently available antiseizure drugs and thus there is a need to develop adjunct therapies to modify disease progression. A vast majority of interventional strategies to treat TLE have utilized males which limits the translational nature of the studies. In this study, we investigated the effects of repeated low-dose kainic acid (KA) injection on the initial status epilepticus (SE) and the effects of Src kinase inhibitor, saracatinib (SAR/AZD0530; 20 mg/kg, oral, daily for 7 days), in a mixed-sex cohort of adult Sprague Dawley rats during early epileptogenesis. There were no sex differences in response to KA-induced SE, and neither did the stage of estrus influence SE severity. KA-induced SE caused significant astrogliosis and microgliosis across the hippocampus, piriform cortex, and amygdala. SAR treatment resulted in a significant reduction of microgliosis across brain regions. Microglial morphometrics such as branch length and the endpoints strongly correlated with CD68 expression in the vehicle-treated group but not in the SAR-treated group, indicating mitigation by SAR. KA-induced SE caused significant neuronal loss, including parvalbumin-positive inhibitory neurons, in both vehicle (VEH) and SAR-treated groups. SAR treatment significantly mitigated FJB-positive neuronal counts as compared to the VEH group. There was an increase in C3-positive reactive astrocytes in the VEH-treated group, and SAR treatment significantly reduced the increase in the piriform cortex. C3-positive astrogliosis significantly correlated with CD68 expression in the amygdala (AMY) of VEH-treated rats, and SAR treatment mitigated this relationship. There was a significant increase of pSrc(Y419)-positive microglia in both KA-treated groups with a statistically insignificant reduction by SAR. KA-induced SE caused the development of classical glial scars in the piriform cortex (PIR) in both KA-treated groups, while SAR treatment led to a 42.17% reduction in the size of glial scars. We did not observe sex differences in any of the parameters in this study. SAR, at the dose tested in the rat kainate model for a week in this study mitigated some of the markers of epileptogenesis in both sexes.
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Affiliation(s)
| | | | | | | | - Thimmasettappa Thippeswamy
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
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Vasanthi SS, Massey N, Nair SN, Mochel JP, Showman L, Thippeswamy T. Exploring the benefits of in-diet versus repeated oral dosing of saracatinib (AZD0530) in chronic studies: insights into pharmacokinetics and animal welfare. Front Vet Sci 2023; 10:1297221. [PMID: 38026620 PMCID: PMC10666625 DOI: 10.3389/fvets.2023.1297221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 10/24/2023] [Indexed: 12/01/2023] Open
Abstract
Saracatinib/AZD0530 (SAR), a Src tyrosine kinase inhibitor, mitigates seizure-induced brain pathology in epilepsy models upon repeated oral dosing. However, repeated dosing is stressful and can be challenging in some seizing animals. To overcome this issue, we have incorporated SAR-in-Diet and compared serum pharmacokinetics (PK) and brain concentrations with conventional repeated oral dosing. Saracatinib in solution or in-diet was stable at room temperature for >4 weeks (97 ± 1.56%). Adult Sprague Dawley rats on SAR-in-Diet consumed ~1.7 g/day less compared to regular diet (16.82 ± 0.6 vs. 18.50 ± 0.5 g/day), but the weight gain/day was unaffected (2.63 ± 0.5 g/day vs. 2.83 ± 0.2 g/day). Importantly, we achieved the anticipated SAR dose range from 2.5-18.7 mg/kg of rat in response to varying concentrations of SAR-in-Diet from 54 to 260 ppm of feed, respectively. There was a strong and significant correlation between SAR-in-Diet dose (mg/kg) and serum saracatinib concentrations (ng/ml). Serum concentrations also did not vary significantly between SAR-in-Diet and repeated oral dosing. The hippocampal saracatinib concentrations derived from SAR-in-Diet treatment were higher than those derived after repeated oral dosing (day 3, 546.8 ± 219.7 ng/g vs. 238.6 ± 143 ng/g; day 7, 300.7 ± 43.4 ng/g vs. 271.1 ± 62.33 ng/g). Saracatinib stability at room temperature and high serum and hippocampal concentrations in animals fed on SAR-in-Diet are useful to titer the saracatinib dose for future animal disease models. Overall, test drugs in the diet is an experimental approach that addresses issues related to handling stress-induced variables in animal experiments.
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Affiliation(s)
- Suraj S. Vasanthi
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Nyzil Massey
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Suresh N. Nair
- Department of Veterinary Pharmacology and Toxicology, College of Veterinary and Animal Sciences, Kerala Veterinary and Animal Sciences University, Thrissur, India
| | - Jonathan P. Mochel
- Precision One Health, Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Lucas Showman
- W.M. Keck Metabolomics Research Laboratory, Iowa State University, Ames, IA, United States
| | - Thimmasettappa Thippeswamy
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
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8
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Brown CW, Chen HY, Panegyres PK. Electroencephalography in young onset dementia. BMC Neurol 2023; 23:202. [PMID: 37221470 DOI: 10.1186/s12883-023-03248-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 05/16/2023] [Indexed: 05/25/2023] Open
Abstract
BACKGROUND Young onset dementia (YOD) is a major diagnostic and management problem. METHODS We set out to explore if electroencephalography (EEG) might be useful in the diagnosis of young onset Alzheimer's disease (YOAD) and young onset frontotemporal dementia (YOFTD). The ARTEMIS project is a 25-year prospective study of YOD based in Perth, Western Australia. 231 participants were included: YOAD: n = 103, YOFTD: n = 28, controls: n = 100. EEGs were performed prospectively, with 30-minute recording time for each subject, without knowledge of diagnosis or other diagnostic data. RESULTS 80.9% of patients with YOD had abnormal EEGs (P < 0.00001). Slow wave changes were more frequent in YOAD that YOFTD (P < 0.00001), but no difference in the frequency of epileptiform activity (P = 0.32), with 38.8% of YOAD and 28.6% of YOFTD patients having epileptiform activity. Slow wave changes were more generalized in YOAD (P = 0.001). Slow wave changes and epileptiform activity were not sensitive to the diagnosis of YOD, but highly specific (97-99%). The absence of slow wave changes and epileptiform activity had a 100% negative predictive value and likelihood radio 0.14 and 0.62 respectively, meaning that those without slow wave changes or epileptiform activity had low probability of having YOD. No relationship was established between EEG findings and the patient's presenting problem. Eleven patients with YOAD developed seizures during the study, and only one with YOFTD. CONCLUSIONS The EEG is highly specific for the diagnosis of YOD with the absence of slow wave changes and epileptiform phenomena making the diagnosis unlikely, with 100% negative predictive value and with low probability for the dementia diagnosis.
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Affiliation(s)
- Casey W Brown
- Faculty of Health and Medical Sciences, The University of Western Australia, Crawley, 6009, Australia
| | - Huei-Yang Chen
- Neurodegenerative Disorders Research Pty Ltd, 4 Lawrence Avenue, West Perth, West Perth, WA, 6005, Australia
| | - Peter K Panegyres
- Faculty of Health and Medical Sciences, The University of Western Australia, Crawley, 6009, Australia.
- Neurodegenerative Disorders Research Pty Ltd, 4 Lawrence Avenue, West Perth, West Perth, WA, 6005, Australia.
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9
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Ali T, Klein AN, Vu A, Arifin MI, Hannaoui S, Gilch S. Peptide aptamer targeting Aβ-PrP-Fyn axis reduces Alzheimer's disease pathologies in 5XFAD transgenic mouse model. Cell Mol Life Sci 2023; 80:139. [PMID: 37149826 PMCID: PMC10164677 DOI: 10.1007/s00018-023-04785-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 04/11/2023] [Accepted: 04/22/2023] [Indexed: 05/08/2023]
Abstract
Currently, no effective therapeutics exist for the treatment of incurable neurodegenerative diseases such as Alzheimer's disease (AD). The cellular prion protein (PrPC) acts as a high-affinity receptor for amyloid beta oligomers (AβO), a main neurotoxic species mediating AD pathology. The interaction of AβO with PrPC subsequently activates Fyn tyrosine kinase and neuroinflammation. Herein, we used our previously developed peptide aptamer 8 (PA8) binding to PrPC as a therapeutic to target the AβO-PrP-Fyn axis and prevent its associated pathologies. Our in vitro results indicated that PA8 prevents the binding of AβO with PrPC and reduces AβO-induced neurotoxicity in mouse neuroblastoma N2a cells and primary hippocampal neurons. Next, we performed in vivo experiments using the transgenic 5XFAD mouse model of AD. The 5XFAD mice were treated with PA8 and its scaffold protein thioredoxin A (Trx) at a 14.4 µg/day dosage for 12 weeks by intraventricular infusion through Alzet® osmotic pumps. We observed that treatment with PA8 improves learning and memory functions of 5XFAD mice as compared to Trx-treated 5XFAD mice. We found that PA8 treatment significantly reduces AβO levels and Aβ plaques in the brain tissue of 5XFAD mice. Interestingly, PA8 significantly reduces AβO-PrP interaction and its downstream signaling such as phosphorylation of Fyn kinase, reactive gliosis as well as apoptotic neurodegeneration in the 5XFAD mice compared to Trx-treated 5XFAD mice. Collectively, our results demonstrate that treatment with PA8 targeting the AβO-PrP-Fyn axis is a promising and novel approach to prevent and treat AD.
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Affiliation(s)
- Tahir Ali
- Calgary Prion Research Unit, Department of Comparative Biology & Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada
- Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Antonia N Klein
- Calgary Prion Research Unit, Department of Comparative Biology & Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada
- Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Alex Vu
- Calgary Prion Research Unit, Department of Comparative Biology & Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada
- Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Maria I Arifin
- Calgary Prion Research Unit, Department of Comparative Biology & Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada
- Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Samia Hannaoui
- Calgary Prion Research Unit, Department of Comparative Biology & Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada
- Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Sabine Gilch
- Calgary Prion Research Unit, Department of Comparative Biology & Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4Z6, Canada.
- Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.
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10
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Andrés-Benito P, Flores Á, Busquet-Areny S, Carmona M, Ausín K, Cartas-Cejudo P, Lachén-Montes M, Del Rio JA, Fernández-Irigoyen J, Santamaría E, Ferrer I. Deregulated Transcription and Proteostasis in Adult mapt Knockout Mouse. Int J Mol Sci 2023; 24:ijms24076559. [PMID: 37047532 PMCID: PMC10095510 DOI: 10.3390/ijms24076559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 03/28/2023] [Accepted: 03/28/2023] [Indexed: 04/14/2023] Open
Abstract
Transcriptomics and phosphoproteomics were carried out in the cerebral cortex of B6.Cg-Mapttm1(EGFP)Klt (tau knockout: tau-KO) and wild-type (WT) 12 month-old mice to learn about the effects of tau ablation. Compared with WT mice, tau-KO mice displayed reduced anxiety-like behavior and lower fear expression induced by aversive conditioning, whereas recognition memory remained unaltered. Cortical transcriptomic analysis revealed 69 downregulated and 105 upregulated genes in tau-KO mice, corresponding to synaptic structures, neuron cytoskeleton and transport, and extracellular matrix components. RT-qPCR validated increased mRNA levels of col6a4, gabrq, gad1, grm5, grip2, map2, rab8a, tubb3, wnt16, and an absence of map1a in tau-KO mice compared with WT mice. A few proteins were assessed with Western blotting to compare mRNA expression with corresponding protein levels. Map1a mRNA and protein levels decreased. However, β-tubulin III and GAD1 protein levels were reduced in tau-KO mice. Cortical phosphoproteomics revealed 121 hypophosphorylated and 98 hyperphosphorylated proteins in tau-KO mice. Deregulated phosphoproteins were categorized into cytoskeletal (n = 45) and membrane proteins, including proteins of the synapses and vesicles, myelin proteins, and proteins linked to membrane transport and ion channels (n = 84), proteins related to DNA and RNA metabolism (n = 36), proteins connected to the ubiquitin-proteasome system (UPS) (n = 7), proteins with kinase or phosphatase activity (n = 21), and 22 other proteins related to variegated pathways such as metabolic pathways, growth factors, or mitochondrial function or structure. The present observations reveal a complex altered brain transcriptome and phosphoproteome in tau-KO mice with only mild behavioral alterations.
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Affiliation(s)
- Pol Andrés-Benito
- Neurologic Diseases and Neurogenetics Group, Bellvitge Institute for Biomedical Research (IDIBELL), 08907 L'Hospitalet de Llobregat, Barcelona, Spain
- CIBERNED (Network Centre of Biomedical Research of Neurodegenerative Diseases), Institute of Health Carlos III, 08907 L'Hospitalet de Llobregat, Barcelona, Spain
| | - África Flores
- Neuropharmacology & Pain Group, Pharmacology Unit, Department of Pathology and Experimental Therapeutics, School of Medicine and Health Sciences, Institute of Neurosciences, University of Barcelona, 08907 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Sara Busquet-Areny
- Neuropathology Group, Bellvitge Institute for Biomedical Research (IDIBELL), 08907 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Margarita Carmona
- CIBERNED (Network Centre of Biomedical Research of Neurodegenerative Diseases), Institute of Health Carlos III, 08907 L'Hospitalet de Llobregat, Barcelona, Spain
- Neuropathology Group, Bellvitge Institute for Biomedical Research (IDIBELL), 08907 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Karina Ausín
- Clinical Neuroproteomics Unit, Proteomics Platform, Proteored-ISCIII, Navarrabiomed, Complejo Hospitalario de Navarra (CHN), Universidad Pública de Navarra (UPNA), diSNA, 31008 Pamplona, Navarra, Spain
| | - Paz Cartas-Cejudo
- Clinical Neuroproteomics Unit, Proteomics Platform, Proteored-ISCIII, Navarrabiomed, Complejo Hospitalario de Navarra (CHN), Universidad Pública de Navarra (UPNA), diSNA, 31008 Pamplona, Navarra, Spain
| | - Mercedes Lachén-Montes
- Clinical Neuroproteomics Unit, Proteomics Platform, Proteored-ISCIII, Navarrabiomed, Complejo Hospitalario de Navarra (CHN), Universidad Pública de Navarra (UPNA), diSNA, 31008 Pamplona, Navarra, Spain
| | - José Antonio Del Rio
- CIBERNED (Network Centre of Biomedical Research of Neurodegenerative Diseases), Institute of Health Carlos III, 08907 L'Hospitalet de Llobregat, Barcelona, Spain
- Molecular and Cellular Neurobiotechnology Group, Institute of Bioengineering of Catalonia (IBEC), Barcelona Institute for Science and Technology, Science Park Barcelona (PCB), 08028 Barcelona, Barcelona, Spain
| | - Joaquín Fernández-Irigoyen
- Clinical Neuroproteomics Unit, Proteomics Platform, Proteored-ISCIII, Navarrabiomed, Complejo Hospitalario de Navarra (CHN), Universidad Pública de Navarra (UPNA), diSNA, 31008 Pamplona, Navarra, Spain
| | - Enrique Santamaría
- Clinical Neuroproteomics Unit, Proteomics Platform, Proteored-ISCIII, Navarrabiomed, Complejo Hospitalario de Navarra (CHN), Universidad Pública de Navarra (UPNA), diSNA, 31008 Pamplona, Navarra, Spain
| | - Isidro Ferrer
- CIBERNED (Network Centre of Biomedical Research of Neurodegenerative Diseases), Institute of Health Carlos III, 08907 L'Hospitalet de Llobregat, Barcelona, Spain
- Neuropathology Group, Bellvitge Institute for Biomedical Research (IDIBELL), 08907 L'Hospitalet de Llobregat, Barcelona, Spain
- Department of Pathology and Experimental Therapeutics, University of Barcelona, 08907 L'Hospitalet de Llobregat, Barcelona, Spain
- Emeritus Researcher, Bellvitge Biomedical Research Institute (IDIBELL), Emeritus Professor, University of Barcelona, 08907 L'Hospitalet de Llobregat, Barcelona, Spain
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11
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Giansante G, Mazzoleni S, Zippo AG, Ponzoni L, Ghilardi A, Maiellano G, Lewerissa E, van Hugte E, Nadif Kasri N, Francolini M, Sala M, Murru L, Bassani S, Passafaro M. Neuronal network activity and connectivity are impaired in a conditional knockout mouse model with PCDH19 mosaic expression. Mol Psychiatry 2023:10.1038/s41380-023-02022-1. [PMID: 36997609 DOI: 10.1038/s41380-023-02022-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 04/01/2023]
Abstract
Mutations in PCDH19 gene, which encodes protocadherin-19 (PCDH19), cause Developmental and Epileptic Encephalopathy 9 (DEE9). Heterogeneous loss of PCDH19 expression in neurons is considered a key determinant of the disorder; however, how PCDH19 mosaic expression affects neuronal network activity and circuits is largely unclear. Here, we show that the hippocampus of Pcdh19 mosaic mice is characterized by structural and functional synaptic defects and by the presence of PCDH19-negative hyperexcitable neurons. Furthermore, global reduction of network firing rate and increased neuronal synchronization have been observed in different limbic system areas. Finally, network activity analysis in freely behaving mice revealed a decrease in excitatory/inhibitory ratio and functional hyperconnectivity within the limbic system of Pcdh19 mosaic mice. Altogether, these results indicate that altered PCDH19 expression profoundly affects circuit wiring and functioning, and provide new key to interpret DEE9 pathogenesis.
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Affiliation(s)
| | - Sara Mazzoleni
- Institute of Neuroscience, CNR, 20854, Vedano al Lambro, Italy
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, 20129, Milano, Italy
| | - Antonio G Zippo
- Institute of Neuroscience, CNR, 20854, Vedano al Lambro, Italy
- NeuroMI Milan Center for Neuroscience, University of Milano-Bicocca, 20126, Milano, Italy
| | - Luisa Ponzoni
- Institute of Neuroscience, CNR, 20854, Vedano al Lambro, Italy
| | - Anna Ghilardi
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, 20129, Milano, Italy
| | - Greta Maiellano
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, 20129, Milano, Italy
| | - Elly Lewerissa
- Radboud University Nijmegen Medical Centre, Donders Institute for Brain, Cognition, and Behaviour, Department of Human Genetics, Department of Human Genetics Cognitive Neuroscience, Nijmegen, Netherlands
| | - Eline van Hugte
- Radboud University Nijmegen Medical Centre, Donders Institute for Brain, Cognition, and Behaviour, Department of Human Genetics, Department of Human Genetics Cognitive Neuroscience, Nijmegen, Netherlands
| | - Nael Nadif Kasri
- Radboud University Nijmegen Medical Centre, Donders Institute for Brain, Cognition, and Behaviour, Department of Human Genetics, Department of Human Genetics Cognitive Neuroscience, Nijmegen, Netherlands
| | - Maura Francolini
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, 20129, Milano, Italy
| | | | - Luca Murru
- Institute of Neuroscience, CNR, 20854, Vedano al Lambro, Italy
- NeuroMI Milan Center for Neuroscience, University of Milano-Bicocca, 20126, Milano, Italy
| | - Silvia Bassani
- Institute of Neuroscience, CNR, 20854, Vedano al Lambro, Italy.
- NeuroMI Milan Center for Neuroscience, University of Milano-Bicocca, 20126, Milano, Italy.
| | - Maria Passafaro
- Institute of Neuroscience, CNR, 20854, Vedano al Lambro, Italy.
- NeuroMI Milan Center for Neuroscience, University of Milano-Bicocca, 20126, Milano, Italy.
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12
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Liew Y, Retinasamy T, Arulsamy A, Ali I, Jones NC, O’Brien TJ, Shaikh MF. Neuroinflammation: A Common Pathway in Alzheimer's Disease and Epilepsy. J Alzheimers Dis 2023; 94:S253-S265. [PMID: 37092226 PMCID: PMC10473147 DOI: 10.3233/jad-230059] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2023] [Indexed: 04/25/2023]
Abstract
BACKGROUND Neuroinflammation is an innate immunological response of the central nervous system that may be induced by a brain insult and chronic neurodegenerative conditions. Recent research has shown that neuroinflammation may contribute to the initiation of Alzheimer's disease (AD) pathogenesis and associated epileptogenesis. OBJECTIVE This systematic review aimed to investigate the available literature on the shared molecular mechanisms of neuroinflammation in AD and epilepsy. METHODS The search included in this systematic review was obtained from 5 established databases. A total of 2,760 articles were screened according to inclusion criteria. Articles related to the modulation of the inflammatory biomarkers commonly associated with the progression of AD and epilepsy in all populations were included in this review. RESULTS Only 7 articles met these criteria and were chosen for further analysis. Selected studies include both in vitro and in vivo research conducted on rodents. Several neuroinflammatory biomarkers were reported to be involved in the cross-talk between AD and epilepsy. CONCLUSION Neuroinflammation was directly associated with the advancement of AD and epilepsy in populations compared to those with either AD or epilepsy. However, more studies focusing on common inflammatory biomarkers are required to develop standardized monitoring guidelines to prevent the manifestation of epilepsy and delay the progression of AD in patients.
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Affiliation(s)
- Yee Liew
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Selangor, Malaysia
| | - Thaarvena Retinasamy
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Selangor, Malaysia
| | - Alina Arulsamy
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Selangor, Malaysia
| | - Idrish Ali
- Department of Neuroscience, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, VIC, Australia
| | - Nigel C. Jones
- Department of Neuroscience, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, VIC, Australia
| | - Terence J. O’Brien
- Department of Neuroscience, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, VIC, Australia
| | - Mohd Farooq Shaikh
- Neuropharmacology Research Laboratory, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Selangor, Malaysia
- Department of Neuroscience, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, VIC, Australia
- School of Dentistry and Medical Sciences, Charles Sturt University, Australia
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13
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Fortner A, Chera A, Tanca A, Bucur O. Apoptosis regulation by the tyrosine-protein kinase CSK. Front Cell Dev Biol 2022; 10:1078180. [PMID: 36578781 PMCID: PMC9792154 DOI: 10.3389/fcell.2022.1078180] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022] Open
Abstract
C-terminal Src kinase (CSK) is a cytosolic tyrosine-protein kinase with an important role in regulating critical cellular decisions, such as cellular apoptosis, survival, proliferation, cytoskeletal organization and many others. Current knowledge on the CSK mechanisms of action, regulation and functions is still at an early stage, most of CSK's known actions and functions being mediated by the negative regulation of the SRC family of tyrosine kinases (SFKs) through phosphorylation. As SFKs play a vital role in apoptosis, cell proliferation and survival regulation, SFK inhibition by CSK has a pro-apoptotic effect, which is mediated by the inhibition of cellular signaling cascades controlled by SFKs, such as the MAPK/ERK, STAT3 and PI3K/AKT signaling pathways. Abnormal functioning of CSK and SFK activation can lead to diseases such as cancer, cardiovascular and neurological manifestations. This review describes apoptosis regulation by CSK, CSK inhibition of the SFKs and further explores the clinical relevance of CSK in important pathologies, such as cancer, autoimmune, autoinflammatory, neurologic diseases, hypertension and HIV/AIDS.
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Affiliation(s)
- Andra Fortner
- Victor Babes National Institute of Pathology, Bucharest, Romania,Medical School, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Alexandra Chera
- Victor Babes National Institute of Pathology, Bucharest, Romania,Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Antoanela Tanca
- Victor Babes National Institute of Pathology, Bucharest, Romania,Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania,*Correspondence: Octavian Bucur, ; Antoanela Tanca,
| | - Octavian Bucur
- Victor Babes National Institute of Pathology, Bucharest, Romania,Viron Molecular Medicine Institute, Boston, MA, United States,*Correspondence: Octavian Bucur, ; Antoanela Tanca,
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14
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Bouillet T, Ciba M, Alves CL, Rodrigues FA, Thielemann C, Colin M, Buée L, Halliez S. Revisiting the involvement of tau in complex neural network remodeling: analysis of the extracellular neuronal activity in organotypic brain slice co-cultures. J Neural Eng 2022; 19. [PMID: 36374001 DOI: 10.1088/1741-2552/aca261] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 11/14/2022] [Indexed: 11/16/2022]
Abstract
Objective.Tau ablation has a protective effect in epilepsy due to inhibition of the hyperexcitability/hypersynchrony. Protection may also occur in transgenic models of Alzheimer's disease by reducing the epileptic activity and normalizing the excitation/inhibition imbalance. However, it is difficult to determine the exact functions of tau, because tau knockout (tauKO) brain networks exhibit elusive phenotypes. In this study, we aimed to further explore the physiological role of tau using brain network remodeling.Approach.The effect of tau ablation was investigated in hippocampal-entorhinal slice co-cultures during network remodeling. We recorded the spontaneous extracellular neuronal activity over 2 weeks in single-slice cultures and co-cultures from control andtauKOmice. We compared the burst activity and applied concepts and analytical tools intended for the analysis of the network synchrony and connectivity.Main results.Comparison of the control andtauKOco-cultures revealed that tau ablation had an anti-synchrony effect on the hippocampal-entorhinal two-slice networks at late stages of culture, in line with the literature. Differences were also found between the single-slice and co-culture conditions, which indicated that tau ablation had differential effects at the sub-network scale. For instance, tau ablation was found to have an anti-synchrony effect on the co-cultured hippocampal slices throughout the culture, possibly due to a reduction in the excitation/inhibition ratio. Conversely, tau ablation led to increased synchrony in the entorhinal slices at early stages of the co-culture, possibly due to homogenization of the connectivity distribution.Significance.The new methodology presented here proved useful for investigating the role of tau in the remodeling of complex brain-derived neural networks. The results confirm previous findings and hypotheses concerning the effects of tau ablation on neural networks. Moreover, the results suggest, for the first time, that tau has multifaceted roles that vary in different brain sub-networks.
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Affiliation(s)
- Thomas Bouillet
- University Lille, Inserm, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Lille F-59000, France
| | - Manuel Ciba
- BioMEMS Lab, University of Applied Sciences Aschaffenburg, Aschaffenburg 63743, Germany
| | - Caroline Lourenço Alves
- BioMEMS Lab, University of Applied Sciences Aschaffenburg, Aschaffenburg 63743, Germany.,Institute of Mathematics and Computer Science, University of São Paulo, São Carlos SP 13566-590, Brazil
| | | | - Christiane Thielemann
- BioMEMS Lab, University of Applied Sciences Aschaffenburg, Aschaffenburg 63743, Germany
| | - Morvane Colin
- University Lille, Inserm, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Lille F-59000, France
| | - Luc Buée
- University Lille, Inserm, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Lille F-59000, France
| | - Sophie Halliez
- University Lille, Inserm, CHU Lille, U1172 - LilNCog - Lille Neuroscience & Cognition, Lille F-59000, France
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15
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Morey N, Przybyla M, van der Hoven J, Ke YD, Delerue F, van Eersel J, Ittner LM. Treatment of epilepsy using a targeted p38γ kinase gene therapy. SCIENCE ADVANCES 2022; 8:eadd2577. [PMID: 36459557 PMCID: PMC10936047 DOI: 10.1126/sciadv.add2577] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 10/19/2022] [Indexed: 06/17/2023]
Abstract
Hyperphosphorylated microtubule-associated protein tau has been implicated in dementia, epilepsy, and other neurological disorders. In contrast, site-specific phosphorylation of tau at threonine 205 (T205) by the kinase p38γ was shown to disengage tau from toxic pathways, serving a neuroprotective function in Alzheimer's disease. Using a viral-mediated gene delivery approach in different mouse models of epilepsy, we show that p38γ activity-enhancing treatment reduces seizure susceptibility, restores neuronal firing patterns, reduces behavioral deficits, and ameliorates epilepsy-induced deaths. Furthermore, we show that p38γ-mediated phosphorylation of tau at T205 is essential for this protection in epilepsy, as a lack of this critical interaction reinstates pathological features and accelerates epilepsy in vivo. Hence, our work provides a scope to harness p38γ as a future therapy applicable to acute neurological conditions.
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Affiliation(s)
- Nicolle Morey
- Dementia Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
| | - Magdalena Przybyla
- Dementia Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
| | - Julia van der Hoven
- Dementia Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
| | - Yazi D. Ke
- Dementia Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
| | - Fabien Delerue
- Dementia Research Centre, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, Australia
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16
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Gage M, Vinithakumari AA, Mooyottu S, Thippeswamy T. Gut dysbiosis following organophosphate, diisopropylfluorophosphate (DFP), intoxication and saracatinib oral administration. FRONTIERS IN MICROBIOMES 2022; 1:1006078. [PMID: 37304619 PMCID: PMC10256240 DOI: 10.3389/frmbi.2022.1006078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Organophosphate nerve agents (OPNAs) act as irreversible inhibitors of acetylcholinesterase and can lead to cholinergic crisis including salivation, lacrimation, urination, defecation, gastrointestinal distress, respiratory distress, and seizures. Although the OPNAs have been studied in the past few decades, little is known about the impact on the gut microbiome which has become of increasing interest across fields. In this study, we challenged animals with the OPNA, diisopropylfluorophosphate (DFP, 4mg/kg, s.c.) followed immediately by 2mg/kg atropine sulfate (i.m.) and 25mg/kg 2-pralidoxime (i.m.) and 30 minutes later by 3mg/kg midazolam (i.m.). One hour after midazolam, animals were treated with a dosing regimen of saracatinib (SAR, 20mg/kg, oral), a src family kinase inhibitor, to mitigate DFP-induced neurotoxicity. We collected fecal samples 48 hours, 7 days, and 5 weeks post DFP intoxication. 16S rRNA genes (V4) were amplified to identify the bacterial composition. At 48 hours, a significant increase in the abundance of Proteobacteria and decrease in the abundance of Firmicutes were observed in DFP treated animals. At 7 days there was a significant reduction in Firmicutes and Actinobacteria, but a significant increase in Bacteroidetes in the DFP groups compared to controls. The taxonomic changes at 5 weeks were negligible. There was no impact of SAR administration on microbial composition. There was a significant DFP-induced reduction in alpha diversity at 48 hours but not at 7 days and 5 weeks. There appeared to be an impact of DFP on beta diversity at 48 hours and 7 days but not at 5 weeks. In conclusion, acute doses of DFP lead to short-term gut dysbiosis and SAR had no effect. Understanding the role of gut dysbiosis in long-term toxicity may reveal therapeutic targets.
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Affiliation(s)
- Meghan Gage
- Interdepartmental Neuroscience, The Departments of Biomedical Sciences, Iowa State University, Ames, IA, United States
| | - Akhil A. Vinithakumari
- Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Shankumar Mooyottu
- Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Thimmasettappa Thippeswamy
- Interdepartmental Neuroscience, The Departments of Biomedical Sciences, Iowa State University, Ames, IA, United States
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17
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Wang Y, Li C, Xiong Z, Chen N, Wang X, Xu J, Wang Y, Liu L, Wu H, Huang C, Huang A, Tan J, Li Y, Li Q. Up-and-coming anti-epileptic effect of aloesone in Aloe vera: Evidenced by integrating network pharmacological analysis, in vitro, and in vivo models. Front Pharmacol 2022; 13:962223. [PMID: 36034878 PMCID: PMC9411719 DOI: 10.3389/fphar.2022.962223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
Background:Aloe vera is a medically valuable plant with anti-epileptic activity; however, its mechanism of action remains unknown. In this study, network pharmacological, in vitro, and in vivo experiments were carried out to explore the potential anti-epileptic components and targets of Aloe vera.Methods: The main active components of Aloe vera were identified by searching the Traditional Chinese Medicine System Pharmacology database. Targets of Aloe vera were predicted using SwissTargetPrediction, whereas information about the epilepsy disease targets was obtained from Gene Cards. The protein–protein interaction network and core targets were screened according to the topological structure and CytoNCA plugin. The glutamate-induced HT22 cell line and pentylenetetrazol-induced seizure rats were used to confirm the effect of aloesone by detecting reactive oxygen species (ROS) and apoptosis, and predicting the targets.Results: A total of 14 core active components were selected based on the screening criteria of oral bioavailability ≥30% and drug-likeness ≥ 0.10. Four compounds, namely linoleic acid, aloesone, isoeleutherol glucosiden qt, and anthranol, demonstrated the potential ability of crossing the blood-brain barrier. A total of 153 targets associated with epilepsy were predicted for the four compounds. Moreover, after network analysis with CytoNCA, 10 targets, namely, MAPK1, SRC, MARK3, EGFR, ESR1, PTGS2, PTPN11, JAK2, PPKCA, and FYN, were selected as the core genes, and SRC, which has been predicted to be the target of aloesone and anthranol, exhibited the highest subgraph centrality value. In vitro experiments confirmed that aloesone treatment significantly inhibited the glutamate-induced neuronal injury by reducing the intracellular ROS content and the early phase of apoptosis. Additionally, treatment with 50 mg/kg aloesone resulted in anti-seizure effects by reducing the seizure score and prolonging the latent period in acute and chronic rats. Furthermore, aloesone treatment increased the phosphorylation of c-SRC at Y418 and reduced the phosphorylation at Y529, simultaneously activating c-SRC.Conclusion: Integrating network pharmacology with in vitro and in vivo experiments demonstrated that aloesone, which inhibited seizure by activating c-SRC, is a potential anti-seizure compound present in Aloe vera.
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Affiliation(s)
- Yan Wang
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Department of Neurology, School of Pharmacy, The First Affiliated Hospital, Hainan Medical University, Haikou, China
- Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province, Department of Neurology, The First Affiliated Hospital of Hainan Medical University, Hainan Medical University, Haikou, China
| | - Chang Li
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Department of Neurology, School of Pharmacy, The First Affiliated Hospital, Hainan Medical University, Haikou, China
- Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province, Department of Neurology, The First Affiliated Hospital of Hainan Medical University, Hainan Medical University, Haikou, China
| | - Zhongyv Xiong
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Department of Neurology, School of Pharmacy, The First Affiliated Hospital, Hainan Medical University, Haikou, China
| | - Niangen Chen
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Department of Neurology, School of Pharmacy, The First Affiliated Hospital, Hainan Medical University, Haikou, China
| | - Xuesong Wang
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Department of Neurology, School of Pharmacy, The First Affiliated Hospital, Hainan Medical University, Haikou, China
| | - Junyv Xu
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Department of Neurology, School of Pharmacy, The First Affiliated Hospital, Hainan Medical University, Haikou, China
| | - Yuemei Wang
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Department of Neurology, School of Pharmacy, The First Affiliated Hospital, Hainan Medical University, Haikou, China
| | - Longfeng Liu
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Department of Neurology, School of Pharmacy, The First Affiliated Hospital, Hainan Medical University, Haikou, China
| | - Hang Wu
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Department of Neurology, School of Pharmacy, The First Affiliated Hospital, Hainan Medical University, Haikou, China
| | - Caihui Huang
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Department of Neurology, School of Pharmacy, The First Affiliated Hospital, Hainan Medical University, Haikou, China
| | - Aiqin Huang
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Department of Neurology, School of Pharmacy, The First Affiliated Hospital, Hainan Medical University, Haikou, China
| | - Jiajia Tan
- College of Veterinary Medicine, Southwestern University, Chongqing, China
| | - Youbin Li
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Department of Neurology, School of Pharmacy, The First Affiliated Hospital, Hainan Medical University, Haikou, China
- *Correspondence: Youbin Li, ; Qifu Li,
| | - Qifu Li
- Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Key Laboratory for Research and Development of Tropical Herbs, Department of Neurology, School of Pharmacy, The First Affiliated Hospital, Hainan Medical University, Haikou, China
- Key Laboratory of Brain Science Research and Transformation in Tropical Environment of Hainan Province, Department of Neurology, The First Affiliated Hospital of Hainan Medical University, Hainan Medical University, Haikou, China
- *Correspondence: Youbin Li, ; Qifu Li,
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del Pozo A, Lehmann L, Knox KM, Barker-Haliski M. Can Old Animals Reveal New Targets? The Aging and Degenerating Brain as a New Precision Medicine Opportunity for Epilepsy. Front Neurol 2022; 13:833624. [PMID: 35572927 PMCID: PMC9096090 DOI: 10.3389/fneur.2022.833624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 04/07/2022] [Indexed: 02/02/2023] Open
Abstract
Older people represent the fastest growing group with epilepsy diagnosis. For example, cerebrovascular disease may underlie roughly 30-50% of epilepsy in older adults and seizures are also an underrecognized comorbidity of Alzheimer's disease (AD). As a result, up to 10% of nursing home residents may take antiseizure medicines (ASMs). Despite the greater incidence of epilepsy in older individuals and increased risk of comorbid seizures in people with AD, aged animals with seizures are strikingly underrepresented in epilepsy drug discovery practice. Increased integration of aged animals into preclinical epilepsy drug discovery could better inform the potential tolerability and pharmacokinetic interactions in aged individuals as the global population becomes increasingly older. Quite simply, the ASMs on the market today were brought forth based on efficacy in young adult, neurologically intact rodents; preclinical information concerning the efficacy and safety of promising ASMs is not routinely evaluated in aged animals. Integrating aged animals more often into basic epilepsy research may also uncover novel treatments for hyperexcitability. For example, cannabidiol and fenfluramine demonstrated clear efficacy in syndrome-specific pediatric models that led to a paradigm shift in the perceived value of pediatric models for ASM discovery practice; aged rodents with seizures or rodents with aging-related neuropathology represent an untapped resource that could similarly change epilepsy drug discovery. This review, therefore, summarizes how aged rodent models have thus far been used for epilepsy research, what studies have been conducted to assess ASM efficacy in aged rodent seizure and epilepsy models, and lastly to identify remaining gaps to engage aging-related neurological disease models for ASM discovery, which may simultaneously reveal novel mechanisms associated with epilepsy.
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Affiliation(s)
| | | | | | - Melissa Barker-Haliski
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA, United States
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19
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Mechanisms Involved in Epileptogenesis in Alzheimer's Disease and Their Therapeutic Implications. Int J Mol Sci 2022; 23:ijms23084307. [PMID: 35457126 PMCID: PMC9030029 DOI: 10.3390/ijms23084307] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 04/09/2022] [Accepted: 04/11/2022] [Indexed: 12/22/2022] Open
Abstract
Epilepsy and Alzheimer's disease (AD) incidence increases with age. There are reciprocal relationships between epilepsy and AD. Epilepsy is a risk factor for AD and, in turn, AD is an independent risk factor for developing epilepsy in old age, and abnormal AD biomarkers in PET and/or CSF are frequently found in late-onset epilepsies of unknown etiology. Accordingly, epilepsy and AD share pathophysiological processes, including neuronal hyperexcitability and an early excitatory-inhibitory dysregulation, leading to dysfunction in the inhibitory GABAergic and excitatory glutamatergic systems. Moreover, both β-amyloid and tau protein aggregates, the anatomopathological hallmarks of AD, have proepileptic effects. Finally, these aggregates have been found in the resection material of refractory temporal lobe epilepsies, suggesting that epilepsy leads to amyloid and tau aggregates. Some epileptic syndromes, such as medial temporal lobe epilepsy, share structural and functional neuroimaging findings with AD, leading to overlapping symptomatology, such as episodic memory deficits and toxic synergistic effects. In this respect, the existence of epileptiform activity and electroclinical seizures in AD appears to accelerate the progression of cognitive decline, and the presence of cognitive decline is much more prevalent in epileptic patients than in elderly patients without epilepsy. Notwithstanding their clinical significance, the diagnosis of clinical seizures in AD is a challenge. Most are focal and manifest with an altered level of consciousness without motor symptoms, and are often interpreted as cognitive fluctuations. Finally, despite the frequent association of epilepsy and AD dementia, there is a lack of clinical trials to guide the use of antiseizure medications (ASMs). There is also a potential role for ASMs to be used as disease-modifying drugs in AD.
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20
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Wang S, Wang B, Shang D, Zhang K, Yan X, Zhang X. Ion Channel Dysfunction in Astrocytes in Neurodegenerative Diseases. Front Physiol 2022; 13:814285. [PMID: 35222082 PMCID: PMC8864228 DOI: 10.3389/fphys.2022.814285] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/03/2022] [Indexed: 11/13/2022] Open
Abstract
Astrocytes play an important role in the central nervous system (CNS). Ion channels in these cells not only function in ion transport, and maintain water/ion metabolism homeostasis, but also participate in physiological processes of neurons and glial cells by regulating signaling pathways. Increasing evidence indicates the ion channel proteins of astrocytes, such as aquaporins (AQPs), transient receptor potential (TRP) channels, adenosine triphosphate (ATP)-sensitive potassium (K-ATP) channels, and P2X7 receptors (P2X7R), are strongly associated with oxidative stress, neuroinflammation and characteristic proteins in neurodegenerative disorders, including Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD) and amyotrophic lateral sclerosis (ALS). Since ion channel protein dysfunction is a significant pathological feature of astrocytes in neurodegenerative diseases, we discuss these critical proteins and their signaling pathways in order to understand the underlying molecular mechanisms, which may yield new therapeutic targets for neurodegenerative disorders.
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Affiliation(s)
- Sijian Wang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Biyao Wang
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Dehao Shang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Kaige Zhang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Xu Yan
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Xinwen Zhang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
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21
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Gage M, Putra M, Wachter L, Dishman K, Gard M, Gomez-Estrada C, Thippeswamy T. Saracatinib, a Src Tyrosine Kinase Inhibitor, as a Disease Modifier in the Rat DFP Model: Sex Differences, Neurobehavior, Gliosis, Neurodegeneration, and Nitro-Oxidative Stress. Antioxidants (Basel) 2021; 11:61. [PMID: 35052568 PMCID: PMC8773289 DOI: 10.3390/antiox11010061] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 12/17/2021] [Accepted: 12/23/2021] [Indexed: 12/13/2022] Open
Abstract
Diisopropylfluorophosphate (DFP), an organophosphate nerve agent (OPNA), exposure causes status epilepticus (SE) and epileptogenesis. In this study, we tested the protective effects of saracatinib (AZD0530), a Src kinase inhibitor, in mixed-sex or male-only Sprague Dawley rats exposed to 4-5 mg/kg DFP followed by 2 mg/kg atropine and 25 mg/kg 2-pralidoxime. Midazolam (3 mg/kg) was given to the mixed-sex cohort (1 h post-DFP) and male-only cohort (~30 min post-DFP). Saracatinib (20 mg/kg, oral, daily for 7 days) or vehicle was given two hours later and euthanized eight days or ten weeks post-DFP. Brain immunohistochemistry (IHC) showed increased microgliosis, astrogliosis, and neurodegeneration in DFP-treated animals. In the 10-week post-DFP male-only group, there were no significant differences between groups in the novel object recognition, Morris water maze, rotarod, or forced swim test. Brain IHC revealed significant mitigation by saracatinib in contrast to vehicle-treated DFP animals in microgliosis, astrogliosis, neurodegeneration, and nitro-oxidative stressors, such as inducible nitric oxide synthase, GP91phox, and 3-Nitrotyrosine. These findings suggest the protective effects of saracatinib on brain pathology seem to depend on the initial SE severity. Further studies on dose optimization, including extended treatment regimen depending on the SE severity, are required to determine its disease-modifying potential in OPNA models.
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Affiliation(s)
| | | | | | | | | | | | - Thimmasettappa Thippeswamy
- Department of Biomedical Sciences and Interdepartmental Neuroscience Program, Iowa State University, Ames, IA 50011, USA; (M.G.); (M.P.); (L.W.); (K.D.); (M.G.); (C.G.-E.)
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22
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Gage M, Putra M, Gomez-Estrada C, Golden M, Wachter L, Gard M, Thippeswamy T. Differential Impact of Severity and Duration of Status Epilepticus, Medical Countermeasures, and a Disease-Modifier, Saracatinib, on Brain Regions in the Rat Diisopropylfluorophosphate Model. Front Cell Neurosci 2021; 15:772868. [PMID: 34720886 PMCID: PMC8555467 DOI: 10.3389/fncel.2021.772868] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 09/28/2021] [Indexed: 11/29/2022] Open
Abstract
Acute organophosphate (OP) toxicity poses a significant threat to both military and civilian personnel as it can lead to a variety of cholinergic symptoms including the development of status epilepticus (SE). Depending on its severity, SE can lead to a spectrum of neurological changes including neuroinflammation and neurodegeneration. In this study, we determined the impact of SE severity and duration on disease promoting parameters such as gliosis and neurodegeneration and the efficacy of a disease modifier, saracatinib (AZD0530), a Src/Fyn tyrosine kinase inhibitor. Animals were exposed to 4 mg/kg diisopropylfluorophosphate (DFP, s.c.) followed by medical countermeasures. We had five experimental groups: controls (no DFP), animals with no continuous convulsive seizures (CS), animals with ∼20-min continuous CS, 31-60-min continuous CS, and > 60-min continuous CS. These groups were then assessed for astrogliosis, microgliosis, and neurodegeneration 8 days after DFP exposure. The 31-60-min and > 60-min groups, but not ∼20-min group, had significantly upregulated gliosis and neurodegeneration in the hippocampus compared to controls. In the piriform cortex and amygdala, however, all three continuous CS groups had significant upregulation in both gliosis and neurodegeneration. In a separate cohort of animals that had ∼20 and > 60-min of continuous CS, we administered saracatinib for 7 days beginning three hours after DFP. There was bodyweight loss and mortality irrespective of the initial SE severity and duration. However, in survived animals, saracatinib prevented spontaneous recurrent seizures (SRS) during the first week in both severity groups. In the ∼20-min CS group, compared to the vehicle, saracatinib significantly reduced neurodegeneration in the piriform cortex and amygdala. There were no significant differences in the measured parameters between the naïve control and saracatinib on its own (without DFP) groups. Overall, this study demonstrates the differential effects of the initial SE severity and duration on the localization of gliosis and neurodegeneration. We have also demonstrated the disease-modifying potential of saracatinib. However, its’ dosing regimen should be optimized based on initial severity and duration of CS during SE to maximize therapeutic effects and minimize toxicity in the DFP model as well as in other OP models such as soman.
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Affiliation(s)
- Meghan Gage
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States.,Neuroscience Interdepartmental Program, Iowa State University, Ames, IA, United States
| | - Marson Putra
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States.,Neuroscience Interdepartmental Program, Iowa State University, Ames, IA, United States
| | - Crystal Gomez-Estrada
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Madison Golden
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Logan Wachter
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Megan Gard
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Thimmasettappa Thippeswamy
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States.,Neuroscience Interdepartmental Program, Iowa State University, Ames, IA, United States
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Sharma S, Carlson S, Gregory-Flores A, Hinojo-Perez A, Olson A, Thippeswamy T. Mechanisms of disease-modifying effect of saracatinib (AZD0530), a Src/Fyn tyrosine kinase inhibitor, in the rat kainate model of temporal lobe epilepsy. Neurobiol Dis 2021; 156:105410. [PMID: 34087381 PMCID: PMC8325782 DOI: 10.1016/j.nbd.2021.105410] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 05/16/2021] [Accepted: 05/30/2021] [Indexed: 02/07/2023] Open
Abstract
We have recently demonstrated the role of the Fyn-PKCδ signaling pathway in status epilepticus (SE)-induced neuroinflammation and epileptogenesis in experimental models of temporal lobe epilepsy (TLE). In this study, we show a significant disease-modifying effect and the mechanisms of a Fyn/Src tyrosine kinase inhibitor, saracatinib (SAR, also known as AZD0530), in the rat kainate (KA) model of TLE. SAR treatment for a week, starting the first dose (25 mg/kg, oral) 4 h after the onset of SE, significantly reduced spontaneously recurring seizures and epileptiform spikes during the four months of continuous video-EEG monitoring. Immunohistochemistry of brain sections and Western blot analyses of hippocampal lysates at 8-day (8d) and 4-month post-SE revealed a significant reduction of SE-induced astrogliosis, microgliosis, neurodegeneration, phosphorylated Fyn/Src-419 and PKCδ-tyr311, in SAR-treated group when compared with the vehicle control. We also found the suppression of nitroxidative stress markers such as iNOS, 3-NT, 4-HNE, and gp91phox in the hippocampus, and nitrite and ROS levels in the serum of the SAR-treated group at 8d post-SE. The qRT-PCR (hippocampus) and ELISA (serum) revealed a significant reduction of key proinflammatory cytokines TNFα and IL-1β mRNA in the hippocampus and their protein levels in serum, in addition to IL-6 and IL-12, in the SAR-treated group at 8d in contrast to the vehicle-treated group. These findings suggest that SAR targets some of the key biomarkers of epileptogenesis and modulates neuroinflammatory and nitroxidative pathways that mediate the development of epilepsy. Therefore, SAR can be developed as a potential disease-modifying agent to prevent the development and progression of TLE.
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Affiliation(s)
- Shaunik Sharma
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames 50011, USA
| | - Steven Carlson
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames 50011, USA
| | - Adriana Gregory-Flores
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames 50011, USA
| | - Andy Hinojo-Perez
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames 50011, USA
| | - Ashley Olson
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames 50011, USA
| | - Thimmasettappa Thippeswamy
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames 50011, USA.
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Gage MC, Thippeswamy T. Inhibitors of Src Family Kinases, Inducible Nitric Oxide Synthase, and NADPH Oxidase as Potential CNS Drug Targets for Neurological Diseases. CNS Drugs 2021; 35:1-20. [PMID: 33515429 PMCID: PMC7893831 DOI: 10.1007/s40263-020-00787-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/20/2020] [Indexed: 12/21/2022]
Abstract
Neurological diseases share common neuroinflammatory and oxidative stress pathways. Both phenotypic and molecular changes in microglia, astrocytes, and neurons contribute to the progression of disease and present potential targets for disease modification. Src family kinases (SFKs) are present in both neurons and glial cells and are upregulated following neurological insults in both human and animal models. In neurons, SFKs interact with post-synaptic protein domains to mediate hyperexcitability and neurotoxicity. SFKs are upstream of signaling cascades that lead to the modulation of neurotransmitter receptors and the transcription of pro-inflammatory cytokines as well as producers of free radicals through the activation of glia. Inducible nitric oxide synthase (iNOS/NOS-II) and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2), the major mediators of reactive nitrogen/oxygen species (RNS/ROS) production in the brain, are also upregulated along with the pro-inflammatory cytokines following neurological insult and contribute to disease progression. Persistent neuronal hyperexcitability, RNS/ROS, and cytokines can exacerbate neurodegeneration, a common pathognomonic feature of the most prevalent neurological disorders such as Alzheimer's disease, Parkinson's disease, and epilepsy. Using a wide variety of preclinical disease models, inhibitors of the SFK-iNOS-NOX2 signaling axis have been tested to cure or modify disease progression. In this review, we discuss the SFK-iNOS-NOX2 signaling pathway and their inhibitors as potential CNS targets for major neurological diseases.
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Affiliation(s)
- Meghan C. Gage
- Iowa State University, Ames, Iowa, United States of America
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