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Zhou C, Satpute V, Yip KL, Anderson LL, Hawkins N, Kearney J, Arnold JC. A high seizure burden increases several prostaglandin species in the hippocampus of a Scn1a +/- mouse model of Dravet syndrome. Prostaglandins Other Lipid Mediat 2024; 172:106836. [PMID: 38599513 DOI: 10.1016/j.prostaglandins.2024.106836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 04/02/2024] [Accepted: 04/05/2024] [Indexed: 04/12/2024]
Abstract
Dravet syndrome is an intractable epilepsy with a high seizure burden that is resistant to current anti-seizure medications. There is evidence that neuroinflammation plays a role in epilepsy and seizures, however few studies have specifically examined neuroinflammation in Dravet syndrome under conditions of a higher seizure burden. Here we used an established genetic mouse model of Dravet syndrome (Scn1a+/- mice), to examine whether a higher seizure burden impacts the number and morphology of microglia in the hippocampus. Moreover, we examined whether a high seizure burden influences classical inflammatory mediators in this brain region. Scn1a+/- mice with a high seizure burden induced by thermal priming displayed a localised reduction in microglial cell density in the granule cell layer and subgranular zone of the dentate gyrus, regions important to postnatal neurogenesis. However, microglial cell number and morphology remained unchanged in other hippocampal subfields. The high seizure burden in Scn1a+/- mice did not affect hippocampal mRNA expression of classical inflammatory mediators such as interleukin 1β and tumour necrosis factor α, but increased cyclooxygenase 2 (COX-2) expression. We then quantified hippocampal levels of prostanoids that arise from COX-2 mediated metabolism of fatty acids and found that Scn1a+/- mice with a high seizure burden displayed increased hippocampal concentrations of numerous prostaglandins, notably PGF2α, PGE2, PGD2, and 6-K-PGF1A, compared to Scn1a+/- mice with a low seizure burden. In conclusion, a high seizure burden increased hippocampal concentrations of various prostaglandin mediators in a mouse model of Dravet syndrome. Future studies could interrogate the prostaglandin pathways to further better understand their role in the pathophysiology of Dravet syndrome.
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Affiliation(s)
- Cilla Zhou
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia; Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Vaishali Satpute
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - Ka Lai Yip
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - Lyndsey L Anderson
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - Nicole Hawkins
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Jennifer Kearney
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Jonathon C Arnold
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia.
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Riikonen R. Biochemical mechanisms in pathogenesis of infantile epileptic spasm syndrome. Seizure 2023; 105:1-9. [PMID: 36634586 DOI: 10.1016/j.seizure.2023.01.004] [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: 09/22/2022] [Revised: 01/01/2023] [Accepted: 01/05/2023] [Indexed: 01/09/2023] Open
Abstract
The molecular mechanisms leading to infantile epileptic spasm syndrome (IESS) remain obscure. The only common factor seems to be that the spasms are restricted to a limited period of infancy, during a certain maturational state. Here the current literature regarding the biochemical mechanisms of brain maturation in IESS is reviewed, and various hypotheses of the pathophysiology are put together. They include: (1) imbalance of inhibitory (NGF, IGF-1, ACTH, GABA) and excitatory factors (glutamate, nitrites) which distinguishes the different etiological subgroups, (2) abnormality of the hypothalamic pituitary adrenal (HPA) axis linking insults and early life stress, (3) inflammation (4) yet poorly known genetic and epigenetic factors, and (5) glucocorticoid and vigabatrin action on brain development, pinpointing at molecular targets of the pathophysiology from another angle. An altered maturational process may explain why so many, seemingly independent etiological factors lead to the same clinical syndrome and frequently to developmental delay. Understanding these factors can provide ideas for novel therapies.
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Affiliation(s)
- Raili Riikonen
- Children's Hospital, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland.
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Iliopoulos G, Daoussis D. FDA-APPROVED INDICATIONS OF ADRENOCORTICOTROPIC HORMONE (ACTH) AS A DRUG: DOES IT HAVE A PLACE IN DISEASE MANAGEMENT TODAY? CENTRAL ASIAN JOURNAL OF MEDICAL HYPOTHESES AND ETHICS 2022. [DOI: 10.47316/cajmhe.2022.3.4.01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
ACTH is a pituitary hormone important for proper function of adrenal glands, cortisol production as well as human physiology in general. It is involved in the pathogenesis of several endocrine disorders like Cushing syndrome and can be a useful diagnostic tool for diseases like primary adrenal insufficiency. Although popular as a hormone in endocrine system physiology and testing, ACTH has been used as a drug since the 1950s. Except for steroid-releasing properties, its mechanism of action involves a steroid-independent anti-inflammatory and possible immune-modulatory effect. Pharmaceutic ACTH has a wide range of indications approved by FDA and usually comes in the form of subcutaneous injections. In this narrative review, we accumulated what we considered as important data from reviews, cases and trials involving the most basic FDA-approved ACTH indications. A special emphasis was given on rheumatologic indications of ACTH. More large data studies need to be performed to assess ACTH usefulness, efficacy, safety and cost-effectiveness as a drug.
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Chauveau F, Becker G, Boutin H. Have (R)-[ 11C]PK11195 challengers fulfilled the promise? A scoping review of clinical TSPO PET studies. Eur J Nucl Med Mol Imaging 2021; 49:201-220. [PMID: 34387719 PMCID: PMC8712292 DOI: 10.1007/s00259-021-05425-w] [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: 02/25/2021] [Accepted: 05/19/2021] [Indexed: 12/19/2022]
Abstract
PURPOSE The prototypical TSPO radiotracer (R)-[11C]PK11195 has been used in humans for more than thirty years to visualize neuroinflammation in several pathologies. Alternative radiotracers have been developed to improve signal-to-noise ratio and started to be tested clinically in 2008. Here we examined the scientific value of these "(R)-[11C]PK11195 challengers" in clinical research to determine if they could supersede (R)-[11C]PK11195. METHODS A systematic MEDLINE (PubMed) search was performed (up to end of year 2020) to extract publications reporting TSPO PET in patients with identified pathologies, excluding studies in healthy subjects and methodological studies. RESULTS Of the 288 publications selected, 152 used 13 challengers, and 142 used (R)-[11C]PK11195. Over the last 20 years, the number of (R)-[11C]PK11195 studies remained stable (6 ± 3 per year), but was surpassed by the total number of challenger studies for the last 6 years. In total, 3914 patients underwent a TSPO PET scan, and 47% (1851 patients) received (R)-[11C]PK11195. The 2 main challengers were [11C]PBR28 (24%-938 patients) and [18F]FEPPA (11%-429 patients). Only one-in-ten patients (11%-447) underwent 2 TSPO scans, among whom 40 (1%) were scanned with 2 different TSPO radiotracers. CONCLUSIONS Generally, challengers confirmed disease-specific initial (R)-[11C]PK11195 findings. However, while their better signal-to-noise ratio seems particularly useful in diseases with moderate and widespread neuroinflammation, most challengers present an allelic-dependent (Ala147Thr polymorphism) TSPO binding and genetic stratification is hindering their clinical implementation. As new challengers, insensitive to TSPO human polymorphism, are about to enter clinical evaluation, we propose this systematic review to be regularly updated (living review).
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Affiliation(s)
- Fabien Chauveau
- University of Lyon, Lyon Neuroscience Research Center (CRNL), CNRS UMR5292, INSERM U1028, University Lyon 1, Lyon, France.
| | - Guillaume Becker
- GIGA - CRC In Vivo Imaging, University Liege, Liege, Belgium
- University of Lyon, CarMeN Laboratory, INSERM U1060, University Lyon 1, Hospices Civils Lyon, Lyon, France
| | - Hervé Boutin
- Faculty of Biology Medicine and Health, Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK.
- Wolfson Molecular Imaging Centre, University of Manchester, Manchester, UK.
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK.
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The role of inflammatory mediators in epilepsy: Focus on developmental and epileptic encephalopathies and therapeutic implications. Epilepsy Res 2021; 172:106588. [PMID: 33721708 DOI: 10.1016/j.eplepsyres.2021.106588] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/28/2021] [Accepted: 02/16/2021] [Indexed: 02/06/2023]
Abstract
In recent years, there has been an increasing interest in the potential involvement of neuroinflammation in the pathogenesis of epilepsy. Specifically, the role of innate immunity (that includes cytokines and chemokines) has been extensively investigated either in animal models of epilepsy and in clinical settings. Developmental and epileptic encephalopathies (DEE) are a heterogeneous group of epileptic disorders, in which uncontrolled epileptic activity results in cognitive, motor and behavioral impairment. By definition, epilepsy in DEE is poorly controlled by common antiepileptic drugs but may respond to alternative treatments, including steroids and immunomodulatory drugs. In this review, we will focus on how cytokines and chemokines play a role in the pathogenesis of DEE and why expanding our knowledge about the role of neuroinflammation in DEE may be crucial to develop new and effective targeted therapeutic strategies to prevent seizure recurrence and developmental regression.
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Chugani HT, Kumar A. Response to Letter by Yue and Yang. J Child Neurol 2021; 36:161. [PMID: 32907449 DOI: 10.1177/0883073820956764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
| | - Ajay Kumar
- Wayne State University, Detroit, MI, USA
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Yue J, Yang H. Letter to the Editor Regarding "Neuroinflammation in Children With Infantile Spasms: A Prospective Study Before and After Treatment with Acthar Gel (Repository Corticotropin Injection)". J Child Neurol 2021; 36:159-160. [PMID: 32907445 DOI: 10.1177/0883073820956769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Jiong Yue
- Epilepsy research center of PLA, Department of Neurosurgery, Xinqiao Hospital, 12525Army Medical University, Chongqing, China
| | - Hui Yang
- Epilepsy research center of PLA, Department of Neurosurgery, Xinqiao Hospital, 12525Army Medical University, Chongqing, China
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