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Bilel S, Zamberletti E, Caffino L, Tirri M, Mottarlini F, Arfè R, Barbieri M, Beggiato S, Boccuto F, Bernardi T, Casati S, Brini AT, Parolaro D, Rubino T, Ferraro L, Fumagalli F, Marti M. Cognitive dysfunction and impaired neuroplasticity following repeated exposure to the synthetic cannabinoid JWH-018 in male mice. Br J Pharmacol 2023; 180:2777-2801. [PMID: 37311647 DOI: 10.1111/bph.16164] [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: 02/11/2022] [Revised: 04/12/2023] [Accepted: 04/18/2023] [Indexed: 06/15/2023] Open
Abstract
BACKGROUND AND PURPOSE Psychotic disorders have been reported in long-term users of synthetic cannabinoids. This study aims at investigating the long-lasting effects of repeated JWH-018 exposure. EXPERIMENTAL APPROACH Male CD-1 mice were injected with vehicle, JWH-018 (6 mg·kg-1 ), the CB1 -antagonist NESS-0327 (1 mg·kg-1 ) or co-administration of NESS-0327 and JWH-018, every day for 7 days. After 15 or 16 days washout, we investigated the effects of JWH-018 on motor function, memory, social dominance and prepulse inhibition (PPI). We also evaluated glutamate levels in dialysates from dorsal striatum, striatal dopamine content and striatal/hippocampal neuroplasticity focusing on the NMDA receptor complex and the neurotrophin BDNF. These measurements were accompanied by in vitro electrophysiological evaluations in hippocampal preparations. Finally, we investigated the density of CB1 receptors and levels of the endocannabinoid anandamide (AEA) and 2-arachidonoylglycerol (2-AG) and their main synthetic and degrading enzymes in the striatum and hippocampus. KEY RESULTS The repeated treatment with JWH-018 induced psychomotor agitation while reducing social dominance, recognition memory and PPI in mice. JWH-018 disrupted hippocampal LTP and decreased BDNF expression, reduced the synaptic levels of NMDA receptor subunits and decreased the expression of PSD95. Repeated exposure to JWH-018, reduced hippocampal CB1 receptor density and induced a long-term alteration in AEA and 2-AG levels and their degrading enzymes, FAAH and MAGL, in the striatum. CONCLUSION AND IMPLICATIONS Our findings suggest that repeated administration of a high dose of JWH-018 leads to the manifestation of psychotic-like symptoms accompanied by alterations in neuroplasticity and change in the endocannabinoid system.
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Affiliation(s)
- Sabrine Bilel
- Department of Translational Medicine, Section of Legal Medicine and LTTA Center, University of Ferrara, Ferrara, Italy
| | - Erica Zamberletti
- Department of Biotechnology and Life Sciences (DBSV) and Neuroscience Center, University of Insubria, Busto Arsizio, Italy
| | - Lucia Caffino
- Department of Pharmacological and Biomolecular Sciences, 'Rodolfo Paoletti', Università degli Studi di Milano, Milan, Italy
| | - Micaela Tirri
- Department of Translational Medicine, Section of Legal Medicine and LTTA Center, University of Ferrara, Ferrara, Italy
| | - Francesca Mottarlini
- Department of Pharmacological and Biomolecular Sciences, 'Rodolfo Paoletti', Università degli Studi di Milano, Milan, Italy
| | - Raffaella Arfè
- Department of Translational Medicine, Section of Legal Medicine and LTTA Center, University of Ferrara, Ferrara, Italy
| | - Mario Barbieri
- Department of Neurosciences and Rehabilitation, University of Ferrara, Ferrara, Italy
| | - Sarah Beggiato
- Department of Life Sciences and Biotechnology (SVeB), University of Ferrara, Ferrara, Italy
| | - Federica Boccuto
- Department of Translational Medicine, Section of Legal Medicine and LTTA Center, University of Ferrara, Ferrara, Italy
| | - Tatiana Bernardi
- Department of Environmental Sciences and Prevention, University of Ferrara, Ferrara, Italy
| | - Sara Casati
- Department of Biomedical Surgical and Dental Sciences, University of Milan, Milan, Italy
| | - Anna T Brini
- Department of Biomedical Surgical and Dental Sciences, University of Milan, Milan, Italy
- IRCCS Galeazzi Orthopedic Institute, Milan, Italy
| | - Daniela Parolaro
- Department of Biotechnology and Life Sciences (DBSV) and Neuroscience Center, University of Insubria, Busto Arsizio, Italy
- Zardi-Gori Foundation, Milan, Italy
| | - Tiziana Rubino
- Department of Biotechnology and Life Sciences (DBSV) and Neuroscience Center, University of Insubria, Busto Arsizio, Italy
| | - Luca Ferraro
- Department of Life Sciences and Biotechnology (SVeB), University of Ferrara, Ferrara, Italy
- Laboratory for the Technology of Advanced Therapies (LTTA Centre), University of Ferrara, Ferrara, Italy
| | - Fabio Fumagalli
- Department of Pharmacological and Biomolecular Sciences, 'Rodolfo Paoletti', Università degli Studi di Milano, Milan, Italy
| | - Matteo Marti
- Department of Translational Medicine, Section of Legal Medicine and LTTA Center, University of Ferrara, Ferrara, Italy
- Collaborative Center for the Italian National Early Warning System, Department of Anti-Drug Policies, Presidency of the Council of Ministers, Rome, Italy
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Tomé D, Dias MS, Correia J, Almeida RD. Fibroblast growth factor signaling in axons: from development to disease. Cell Commun Signal 2023; 21:290. [PMID: 37845690 PMCID: PMC10577959 DOI: 10.1186/s12964-023-01284-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/18/2023] [Indexed: 10/18/2023] Open
Abstract
The fibroblast growth factor (FGF) family regulates various and important aspects of nervous system development, ranging from the well-established roles in neuronal patterning to more recent and exciting functions in axonal growth and synaptogenesis. In addition, FGFs play a critical role in axonal regeneration, particularly after spinal cord injury, confirming their versatile nature in the nervous system. Due to their widespread involvement in neural development, the FGF system also underlies several human neurological disorders. While particular attention has been given to FGFs in a whole-cell context, their effects at the axonal level are in most cases undervalued. Here we discuss the endeavor of the FGF system in axons, we delve into this neuronal subcompartment to provide an original view of this multipurpose family of growth factors in nervous system (dys)function. Video Abstract.
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Affiliation(s)
- Diogo Tomé
- Institute of Biomedicine, Department of Medical Sciences - iBiMED, University of Aveiro, Aveiro, Portugal
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Marta S Dias
- Institute of Biomedicine, Department of Medical Sciences - iBiMED, University of Aveiro, Aveiro, Portugal
| | - Joana Correia
- Institute of Biomedicine, Department of Medical Sciences - iBiMED, University of Aveiro, Aveiro, Portugal
| | - Ramiro D Almeida
- Institute of Biomedicine, Department of Medical Sciences - iBiMED, University of Aveiro, Aveiro, Portugal.
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.
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Yin N, Wang HN, Ding WW, Zhou H, Li SY, Miao Y, Li F, Lei B, Wang Z. Dopamine receptor-mediated roles on retinal ganglion cell hyperexcitability and injury in experimental glaucoma. Cell Signal 2023:110781. [PMID: 37354963 DOI: 10.1016/j.cellsig.2023.110781] [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: 11/20/2022] [Revised: 06/14/2023] [Accepted: 06/21/2023] [Indexed: 06/26/2023]
Abstract
Extraordinary excitability (hyperexcitability) is closely related to retinal ganglion cell (RGC) injury in glaucoma. Dopamine (DA) and its receptors are involved in modulating RGC excitability. We investigated how DA system affects RGC injury in chronic ocular hypertension (COH) experimental glaucoma model. Western blotting and immunohistochemistry results revealed that expression of DA D2-like receptor (D2R) in RGCs was increased in COH retinas. Patch-clamp recordings showed that outward K+ currents were downregulated, while Na+ currents and NaV1.6 expression were upregulated in RGCs of COH retinas, which could be reversed by intravitreal pre-injection of the D2R antagonist sulpiride, but not by the D1-like receptor (D1R) antagonist SCH23390. However, pre-injection of the D1R agonist SKF81297 could partially reverse the increased expression of NaV1.6 proteins. Consistently, the numbers of evoked action potentials induced by current injections were increased in RGCs of COH retinas, indicating that RGCs may be in a condition of hyperexcitability. The increased frequency of evoked action potentials could be partially block by pre-injection of sulpiride, SKF81297 or DA, respectively. Furthermore, the increased number of TUNEL-positive RGCs in COH retinas could be partially reduced by intravitreal pre-injection of sulpiride, but not by pre-injection of SCH23390. Moreover, pre-injection of SKF81297 or DA could reduce the number of TUNEL-positive RGCs in COH retinas. All these results indicate that in COH retina, activation of D2R enhances RGC hyperexcitability and injury, while activation of D1R results in the opposite effects. Selective inhibition of D2R or activation of D1R may be an effective strategy for treatment of glaucoma.
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Affiliation(s)
- Ning Yin
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Hong-Ning Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Wen-Wen Ding
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Han Zhou
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Shu-Ying Li
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Yanying Miao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Fang Li
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China
| | - Bo Lei
- Institutes of Neuroscience and Third Affiliated Hospital, Henan Provincial People's Hospital, Henan Eye Institute, Henan Eye Hospital, People's Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou 450003, China
| | - Zhongfeng Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai 200032, China.
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Pang Y, Luo D, Wang S. miR-128-3p inhibits the inflammation by targeting MAPK6 in penicillin-induced astrocytes. Neuroreport 2022; 33:742-749. [PMID: 36250437 PMCID: PMC9622368 DOI: 10.1097/wnr.0000000000001840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 09/07/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Epilepsy causes physical and mental damage to patients. As well known, microRNAs (miRNAs) provide therapeutic target potentials for patients with epilepsy. miR-128-3p was previously reported to be downregulated in temporal lobe epilepsy (TLE) patients, however, its detailed function in epilepsy is unknown. METHODS Astrocytes function in epilepsy, penicillin-induced astrocytes can be used as a model for seizures in vitro. Currently, the expression levels of mitogen-activated protein kinase 6 (MAPK6), interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) were determined by western blot and reverse transcription-quantitative PCR analyses (RT-qPCR). The expression level of miR-128-3p was evaluated by RT-qPCR. TargetScan 7.1 and dual luciferase reporter assay were used for prediction and verification of interaction between miR-128-3p and MAPK6 3' untranslated region (UTR). Cell viability was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. RESULTS We found that penicillin-induced decrease in cell viability, and increase of TNF-α/IL-1β in primary astrocytes. There were lower miR-128-3p and higher MAPK6 in penicillin-treated primary astrocytes. miR-128-3p overexpression rescued penicillin-induced reduction of cell viability, and upregulation of TNF-α/IL-1β, which was partially abolished by MAPK6 overexpression. CONCLUSION Altogether, miR-128-3p attenuates penicillin-induced cell injury and inflammation in astrocytes by targeting MAPK6, thus providing a protective role in epilepsy.
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Affiliation(s)
| | | | - Shuhua Wang
- Health Examination Center, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Ji’nan, Shandong 250021, China
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5
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Cheng S, Wang HN, Xu LJ, Li F, Miao Y, Lei B, Sun X, Wang Z. Soluble tumor necrosis factor-alpha-induced hyperexcitability contributes to retinal ganglion cell apoptosis by enhancing Nav1.6 in experimental glaucoma. J Neuroinflammation 2021; 18:182. [PMID: 34419081 PMCID: PMC8380326 DOI: 10.1186/s12974-021-02236-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 08/09/2021] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Neuroinflammation plays an important role in the pathogenesis of glaucoma. Tumor necrosis factor-alpha (TNF-α) is a major pro-inflammatory cytokine released from activated retinal glial cells in glaucoma. Here, we investigated how TNF-α induces retinal ganglion cell (RGC) hyperexcitability and injury. METHODS Whole-cell patch-clamp techniques were performed to explore changes in spontaneous firing and evoked action potentials, and Na+ currents in RGCs. Both intravitreal injection of TNF-α and chronic ocular hypertension (COH) models were used. Western blotting, immunofluorescence, quantitative real-time polymerase chain reaction (q-PCR), and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) techniques were employed to investigate the molecular mechanisms of TNF-α effects on RGCs. RESULTS Intravitreal injection of soluble TNF-α significantly increased the spontaneous firing frequencies of RGCs in retinal slices. When the synaptic transmissions were blocked, more than 90% of RGCs still showed spontaneous firing; both the percentage of cells and firing frequency were higher than the controls. Furthermore, the frequency of evoked action potentials was also higher than the controls. Co-injection of the TNF-α receptor 1 (TNFR1) inhibitor R7050 eliminated the TNF-α-induced effects, suggesting that TNF-α may directly act on RGCs to induce cell hyperexcitability through activating TNFR1. In RGCs acutely isolated from TNF-α-injected retinas, Na+ current densities were upregulated. Perfusing TNF-α in RGCs of normal rats mimicked this effect, and the activation curve of Na+ currents shifted toward hyperpolarization direction, which was mediated through p38 MAPK and STAT3 signaling pathways. Further analysis revealed that TNF-α selectively upregulated Nav1.6 subtype of Na+ currents in RGCs. Similar to observations in retinas of rats with COH, intravitreal injection of TNF-α upregulated the expression of Nav1.6 proteins in both total cell and membrane components, which was reversed by the NF-κB inhibitor BAY 11-7082. Inhibition of TNFR1 blocked TNF-α-induced RGC apoptosis. CONCLUSIONS TNF-α/TNFR1 signaling induces RGC hyperexcitability by selectively upregulating Nav1.6 Na+ channels, thus contributing to RGC apoptosis in glaucoma.
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Affiliation(s)
- Shuo Cheng
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Hong-Ning Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Lin-Jie Xu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Fang Li
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Yanying Miao
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China
| | - Bo Lei
- Institute of Neuroscience and Third Affiliated Hospital, Henan Provincial People's Hospital, Henan Eye Institute, Henan Eye Hospital, People's Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, 450003, China
| | - Xinghuai Sun
- Department of Ophthalmology at Eye & ENT Hospital, Shanghai Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, 200031, China.
| | - Zhongfeng Wang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, 200032, China.
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6
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Upadhya R, Zingg W, Shetty S, Shetty AK. Astrocyte-derived extracellular vesicles: Neuroreparative properties and role in the pathogenesis of neurodegenerative disorders. J Control Release 2020; 323:225-239. [PMID: 32289328 DOI: 10.1016/j.jconrel.2020.04.017] [Citation(s) in RCA: 132] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 04/08/2020] [Accepted: 04/09/2020] [Indexed: 12/11/2022]
Abstract
Extracellular vesicles (EVs) released by neural cells play an essential role in brain homeostasis and the crosstalk between neural cells and the periphery. EVs are diverse, nano-sized vesicles, which transport proteins, nucleic acids, and lipids between cells over short and long expanses and hence are proficient for modulating the target cells. EVs released from neural cells are implicated in synaptic plasticity, neuron-glia interface, neuroprotection, neuroregeneration, and the dissemination of neuropathological molecules. This review confers the various properties of EVs secreted by astrocytes and their potential role in health and disease with a focus on evolving concepts. Naïve astrocytes shed EVs containing a host of neuroprotective compounds, which include fibroblast growth factor-2, vascular endothelial growth factor, and apolipoprotein-D. Stimulated astrocytes secrete EVs with neuroprotective molecules including heat shock proteins, synapsin 1, unique microRNAs, and glutamate transporters. Well-characterized astrocyte-derived EVs (ADEVs) generated in specific culture conditions and ADEVs that are engineered to carry the desired miRNAs or proteins are likely useful for treating brain injury and neurogenerative diseases. On the other hand, in conditions such as Alzheimer's disease (AD), stroke, Parkinson's disease, Amyotrophic lateral sclerosis (ALS), and other neuroinflammatory conditions, EVs released by activated astrocytes appear to mediate or exacerbate the pathological processes. The examples include ADEVs spreading the dysregulated complement system in AD, mediating motoneuron toxicity in ALS, and stimulating peripheral leukocyte migration into the brain in inflammatory conditions. Strategies restraining the release of EVs by activated astrocytes or modulating the composition of ADEVs are likely beneficial for treating neurodegenerative diseases. Also, periodic analyses of ADEVs in the blood is useful for detecting astrocyte-specific biomarkers in different neurological conditions and for monitoring disease progression and remission with distinct therapeutic approaches.
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Affiliation(s)
- Raghavendra Upadhya
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA
| | - Winston Zingg
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA
| | - Siddhant Shetty
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA
| | - Ashok K Shetty
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University College of Medicine, College Station, TX, USA.
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Carmen-Orozco RP, Dávila-Villacorta DG, Cauna Y, Bernal-Teran EG, Bitterfeld L, Sutherland GL, Chile N, Céliz RH, Ferrufino-Schmidt MC, Gavídia CM, Sterling CR, García HH, Gilman RH, Verástegui MR. Blood-brain barrier disruption and angiogenesis in a rat model for neurocysticercosis. J Neurosci Res 2018; 97:137-148. [PMID: 30315659 DOI: 10.1002/jnr.24335] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 09/13/2018] [Accepted: 09/14/2018] [Indexed: 12/13/2022]
Abstract
Neurocysticercosis (NCC) is a helminth infection affecting the central nervous system caused by the larval stage (cysticercus) of Taenia solium. Since vascular alteration and blood-brain barrier (BBB) disruption contribute to NCC pathology, it is postulated that angiogenesis could contribute to the pathology of this disease. This study used a rat model for NCC and evaluated the expression of two angiogenic factors called vascular endothelial growth factor (VEGF-A) and fibroblast growth factor (FGF2). Also, two markers for BBB disruption, the endothelial barrier antigen and immunoglobulin G, were evaluated using immunohistochemical and immunofluorescence techniques. Brain vasculature changes, BBB disruption, and overexpression of angiogenesis markers surrounding viable cysts were observed. Both VEGF-A and FGF2 were overexpressed in the tissue surrounding the cysticerci, and VEGF-A was overexpressed in astrocytes. Vessels showed decreased immunoreactivity to endothelial barrier antigen marker and an extensive staining for IgG was found in the tissues surrounding the cysts. Additionally, an endothelial cell tube formation assay using human umbilical vein endothelial cells showed that excretory and secretory antigens of T. solium cysticerci induce the formation of these tubes. This in vitro model supports the hypothesis that angiogenesis in NCC might be caused by the parasite itself, as opposed to the host inflammatory responses alone. In conclusion, brain vasculature changes, BBB disruption, and overexpression of angiogenesis markers surrounding viable cysts were observed. This study also demonstrates that cysticerci excretory-secretory processes alone can stimulate angiogenesis.
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Affiliation(s)
- Rogger P Carmen-Orozco
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Danitza G Dávila-Villacorta
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Yudith Cauna
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Edson G Bernal-Teran
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Leandra Bitterfeld
- The Department of International Health, Bloomberg School of Hygiene and Public Health, The Johns Hopkins University, Baltimore, Maryland
| | - Graham L Sutherland
- The Department of International Health, Bloomberg School of Hygiene and Public Health, The Johns Hopkins University, Baltimore, Maryland
| | - Nancy Chile
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Rensson H Céliz
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - María C Ferrufino-Schmidt
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
| | - Cesar M Gavídia
- School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Perú
| | - Charles R Sterling
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona
| | - Héctor H García
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú.,Cysticercosis Unit, Instituto de Nacional Ciencias Neurológicas, Lima, Perú
| | - Robert H Gilman
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú.,The Department of International Health, Bloomberg School of Hygiene and Public Health, The Johns Hopkins University, Baltimore, Maryland.,Asociación Benéfica PRISMA, Lima, Perú
| | - Manuela Renee Verástegui
- Infectious Diseases Laboratory Research-LID, Faculty of Science and Philosophy, Alberto Cazorla Talleri, Universidad Peruana Cayetano Heredia, Lima, Perú
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Simonato M. Neurotrophic factors and status epilepticus. Epilepsia 2018; 59 Suppl 2:87-91. [DOI: 10.1111/epi.14501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/23/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Michele Simonato
- Department of Medical Sciences; University of Ferrara; Ferrara Italy
- Division of Neuroscience; University Vita-Salute San Raffaele; Milan Italy
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9
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Taetzsch T, Brayman VL, Valdez G. FGF binding proteins (FGFBPs): Modulators of FGF signaling in the developing, adult, and stressed nervous system. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2983-2991. [PMID: 29902550 DOI: 10.1016/j.bbadis.2018.06.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/17/2018] [Accepted: 06/09/2018] [Indexed: 01/18/2023]
Abstract
Members of the fibroblast growth factor (FGF) family are involved in a variety of cellular processes. In the nervous system, they affect the differentiation and migration of neurons, the formation and maturation of synapses, and the repair of neuronal circuits following insults. Because of the varied yet critical functions of FGF ligands, their availability and activity must be tightly regulated for the nervous system, as well as other tissues, to properly develop and function in adulthood. In this regard, FGF binding proteins (FGFBPs) have emerged as strong candidates for modulating the actions of secreted FGFs in neural and non-neural tissues. Here, we will review the roles of FGFBPs in the peripheral and central nervous systems.
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Affiliation(s)
- Thomas Taetzsch
- Virginia Tech Carilion Research Institute, Roanoke, VA, USA.
| | - Vanessa L Brayman
- Virginia Tech Carilion Research Institute, Roanoke, VA, USA; Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA, USA.
| | - Gregorio Valdez
- Virginia Tech Carilion Research Institute, Roanoke, VA, USA; Department of Biological Sciences, Virginia Tech, Blacksburg, VA, USA.
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10
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Involvement of mGluR I in EphB/ephrinB reverse signaling activation induced retinal ganglion cell apoptosis in a rat chronic hypertension model. Brain Res 2018; 1683:27-35. [PMID: 29366625 DOI: 10.1016/j.brainres.2018.01.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 01/05/2018] [Accepted: 01/17/2018] [Indexed: 02/08/2023]
Abstract
EphB/ephrinB reverse signaling is involved in retinal ganglion cell (RGC) apoptosis in experimental glaucoma. Here, we further investigated the mechanisms underlying EphB/ephrinB reverse signaling activation induced RGC apoptosis in a rat chronic ocular hypertension (COH) model, using patch-clamp techniques in retinal slices. In COH retinas, RGCs showed higher spontaneous firing frequency and much more depolarized membrane potential as compared to control, which was mimicked by intravitreally injection of EphB2-Fc, an activator of ephrinB2. The changes in RGC spontaneous firing and membrane potential could be reversed by the tyrosine kinase inhibitor PP2, suggesting that EphB/ephrinB reverse signaling activation induced RGC hyperexcitability. Intravitreal pre-injection of either LY367385 or MPEP, selective mGluR1 and mGluR5 antagonists, also blocked the changes in RGC spontaneous firing and membrane potential. Co-immunoprecipitation experiments showed an interaction between ephrinB2 and group I metabotropic glutamate receptor (mGluR I) (mGluR1/mGluR5). Furthermore, intravitreal pre-injection of the mixture of L-NAME (an NO synthase inhibitor) and XPro1595 (a selective inhibitor of soluble TNF-α) could reduce the EphB2-Fc injection induced increase in RGC firing, suggesting that Müller cells might be involved in EphB/ephrinB reverse signaling activation induced change in RGC hyperexcitability. In addition, LY367385/MPEP reduced the numbers of TUNEL-positive RGCs both in EphB2-Fc injected and COH retinas. All results suggest that activation of EphB/ephrinB reverse signaling induces RGC hyperexcitability and apoptosis by interacting with mGluR I in COH rats. Appropriate reduction of EphB/ephrinB reverse signaling could alleviate the loss of RGCs in glaucoma.
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Vitale G, Filaferro M, Micioni Di Bonaventura MV, Ruggieri V, Cifani C, Guerrini R, Simonato M, Zucchini S. Effects of [Nphe 1, Arg 14, Lys 15] N/OFQ-NH 2 (UFP-101), a potent NOP receptor antagonist, on molecular, cellular and behavioural alterations associated with chronic mild stress. J Psychopharmacol 2017; 31:691-703. [PMID: 28417659 DOI: 10.1177/0269881117691456] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The present study investigated the effect of [Nphe1] Arg14, Lys15-N/OFQ-NH2 (UFP-101), a selective NOP receptor antagonist, in chronic mild stress (CMS) in male Wistar rats. NOP receptor antagonists were reported to elicit antidepressant-like effects in rodents. Our aim was to investigate UFP-101 effects on CMS-induced anhedonia and impairment of hippocampal neurogenesis. UFP-101 (10 nmol/rat intracerebroventricularly) did not influence sucrose intake in non-stressed animals, but reinstated basal sucrose consumption in stressed animals from the second week of treatment. UFP-101 also reversed stress effects in forced swimming test and in open field. Fluoxetine (10 mg/kg intraperitoneally) produced similar effects. Moreover, we investigated whether UFP-101 could affect CMS-induced impairment in hippocampal cell proliferation and neurogenesis, and in fibroblast growth factor (FGF-2) expression. Our data confirm that CMS reduced neural stem cell proliferation and neurogenesis in adult rat hippocampus. Chronic UFP-101 treatment did not affect the reduced proliferation (bromodeoxyuridine-positive cells) observed in stressed animals. However, UFP-101 increased the number of doublecortin-positive cells, restoring neurogenesis. Finally, UFP-101 significantly increased FGF-2 expression, reduced by CMS. These findings support the view that blockade of NOP receptors produces antidepressant-like effects in CMS associated with positive effects on neurogenesis and FGF-2 expression. Therefore, NOP receptors may represent a target for innovative antidepressant drugs.
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Affiliation(s)
- Giovanni Vitale
- 1 Department Life Sciences, University of Modena and RE, Modena, Italy
| | - Monica Filaferro
- 2 Department Biomedical, Metabolical and Neuro-Sciences, University of Modena and RE, Modena, Italy
| | | | - Valentina Ruggieri
- 4 Department Medical and Surgical Sciences for Children & Adults - University Hospital of Modena, Modena, Italy
| | - Carlo Cifani
- 3 School of Pharmacy, Pharmacology Unit, University of Camerino, Camerino, Italy
| | - Remo Guerrini
- 5 Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy
| | - Michele Simonato
- 6 Department Medical Sciences and Laboratory for the Technologies for Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
| | - Silvia Zucchini
- 6 Department Medical Sciences and Laboratory for the Technologies for Advanced Therapies (LTTA), University of Ferrara, Ferrara, Italy
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12
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Barbieri M, Ossato A, Canazza I, Trapella C, Borelli AC, Beggiato S, Rimondo C, Serpelloni G, Ferraro L, Marti M. Synthetic cannabinoid JWH-018 and its halogenated derivatives JWH-018-Cl and JWH-018-Br impair Novel Object Recognition in mice: Behavioral, electrophysiological and neurochemical evidence. Neuropharmacology 2016; 109:254-269. [PMID: 27346209 DOI: 10.1016/j.neuropharm.2016.06.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/14/2016] [Accepted: 06/22/2016] [Indexed: 01/29/2023]
Abstract
It is well known that an impairment of learning and memory function is one of the major physiological effects caused by natural or synthetic cannabinoid consumption in rodents, nonhuman primates and in humans. JWH-018 and its halogenated derivatives (JWH-018-Cl and JWH-018-Br) are synthetic CB1/CB2 cannabinoid agonists, illegally marketed as "Spice" and "herbal blend" for their Cannabis-like psychoactive effects. In the present study the effects of acute exposure to JWH-018, JWH-018-Cl, JWH-018-Br (JWH-018-R compounds) and Δ(9)-THC (for comparison) on Novel Object Recognition test (NOR) has been investigated in mice. Moreover, to better characterize the effects of JWH-018-R compounds on memory function, in vitro electrophysiological and neurochemical studies in hippocampal preparations have been performed. JWH-018, JWH-018-Cl and JWH-018-Br dose-dependently impaired both short- and long-memory retention in mice (respectively 2 and 24 h after training session). Their effects resulted more potent respect to that evoked by Δ(9)-THC. Moreover, in vitro studies showed as JWH-018-R compounds negatively affected electrically evoked synaptic transmission, LTP and aminoacid (glutamate and GABA) release in hippocampal slices. Behavioral, electrophysiological and neurochemical effects were fully prevented by CB1 receptor antagonist AM251 pretreatment, suggesting a CB1 receptor involvement. These data support the hypothesis that synthetic JWH-018-R compounds, as Δ(9)-THC, impair cognitive function in mice by interfering with hippocampal synaptic transmission and memory mechanisms. This data outline the danger that the use and/or abuse of these synthetic cannabinoids may represent for the cognitive process in human consumer.
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Affiliation(s)
- M Barbieri
- Department of Medical Sciences, University of Ferrara, Italy
| | - A Ossato
- Department of Life Sciences and Biotechnology (SVeB), University of Ferrara, Italy
| | - I Canazza
- Department of Life Sciences and Biotechnology (SVeB), University of Ferrara, Italy
| | - C Trapella
- Department of Chemistry and Pharmaceutical Sciences, University of Ferrara, Italy
| | - A C Borelli
- Department of Medical Sciences, University of Ferrara, Italy
| | - S Beggiato
- Department of Life Sciences and Biotechnology (SVeB), University of Ferrara, Italy
| | - C Rimondo
- Department of Public Health and Community Medicine, University of Verona, Italy
| | - G Serpelloni
- U.R.I.To.N., Forensic Toxicology Unit, Department of Health Science, University of Florence, Florence, Italy
| | - L Ferraro
- Department of Life Sciences and Biotechnology (SVeB), University of Ferrara, Italy
| | - M Marti
- Department of Life Sciences and Biotechnology (SVeB), University of Ferrara, Italy; Center for Neuroscience and Istituto Nazionale di Neuroscienze, Italy.
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Sun M, Liu H, Xu H, Wang H, Wang X. CNTF-Treated Astrocyte Conditioned Medium Enhances Large-Conductance Calcium-Activated Potassium Channel Activity in Rat Cortical Neurons. Neurochem Res 2016; 41:1982-92. [PMID: 27097551 DOI: 10.1007/s11064-016-1910-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 04/03/2016] [Accepted: 04/05/2016] [Indexed: 11/28/2022]
Abstract
Seizure activity is linked to astrocyte activation as well as dysfunctional cortical neuron excitability produced from changes in calcium-activated potassium (KCa) channel function. Ciliary neurotrophic factor-treated astrocyte conditioned medium (CNTF-ACM) can be used to investigate the peripheral effects of activated astrocytes upon cortical neurons. However, CNTF-ACM's effect upon KCa channel activity in cultured cortical neurons has not yet been investigated. Whole-cell patch clamp recordings were performed in rat cortical neurons to evaluate CNTF-ACM's effects upon charybdotoxin-sensitive large-conductance KCa (BK) channel currents and apamin-sensitive small-conductance KCa (SK) channel current. Biotinylation and RT-PCR were applied to assess CNTF-ACM's effects upon the protein and mRNA expression, respectively, of the SK channel subunits SK2 and SK3 and the BK channel subunits BKα1 and BKβ3. An anti-fibroblast growth factor-2 (FGF-2) monoclonal neutralizing antibody was used to assess the effects of the FGF-2 component of CNTF-ACM. CNTF-ACM significantly increased KCa channel current density, which was predominantly attributable to gains in BK channel activity (p < 0.05). CNTF-ACM produced a significant increase in BKα1 and BKβ3 expression (p < 0.05) but had no significant effect upon SK2 or SK3 expression (p > 0.05). Blocking FGF-2 produced significant reductions in KCa channel current density (p > 0.05) as well as BKα1 and BKβ3 expression in CNTF-ACM-treated neurons (p > 0.05). CNTF-ACM significantly enhances BK channel activity in rat cortical neurons and that FGF-2 is partially responsible for these effects. CNTF-induced astrocyte activation results in secretion of neuroactive factors which may affect neuronal excitability and resultant seizure activity in mammalian cortical neurons.
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Affiliation(s)
- Meiqun Sun
- Department of Histology and Embryology, Bengbu Medical College, Bengbu, Anhui, China
| | - Hongli Liu
- Department of Gynecological Oncology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, China
| | - Huanbai Xu
- Department of Endocrinology and Metabolism, Shanghai Jiaotong University Affiliated First People's Hospital, Shanghai, China
| | - Hongtao Wang
- Department of Immunology, Bengbu Medical College, Bengbu, Anhui, China
| | - Xiaojing Wang
- Department of Respiration, Anhui Clinical and Preclinical Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Bengbu Medical College, No. 287 Changhuai Road, Bengbu, Anhui, 233000, China.
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14
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Williams AJ, Yee P, Smith MC, Murphy GG, Umemori H. Deletion of fibroblast growth factor 22 (FGF22) causes a depression-like phenotype in adult mice. Behav Brain Res 2016; 307:11-7. [PMID: 27036645 DOI: 10.1016/j.bbr.2016.03.047] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 03/25/2016] [Accepted: 03/28/2016] [Indexed: 12/15/2022]
Abstract
Specific growth factors induce formation and differentiation of excitatory and inhibitory synapses, and are essential for brain development and function. Fibroblast growth factor 22 (FGF22) is important for specifying excitatory synapses during development, including in the hippocampus. Mice with a genetic deletion of FGF22 (FGF22KO) during development subsequently have fewer hippocampal excitatory synapses in adulthood. As a result, FGF22KO mice are resistant to epileptic seizure induction. In addition to playing a key role in learning, the hippocampus is known to mediate mood and anxiety. Here, we explored whether loss of FGF22 alters affective, anxiety or social cognitive behaviors in mice. We found that relative to control mice, FGF22KO mice display longer duration of floating and decreased latency to float in the forced swim test, increased immobility in the tail suspension test, and decreased preference for sucrose in the sucrose preference test, which are all suggestive of a depressive-like phenotype. No differences were observed between control and FGF22KO mice in other behavioral assays, including motor, anxiety, or social cognitive tests. These results suggest a novel role for FGF22 specifically in affective behaviors.
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Affiliation(s)
- Aislinn J Williams
- Molecular and Behavioral Neuroscience Institute and Department of Psychiatry, University of Michigan, Ann Arbor, MI, United States.
| | - Patricia Yee
- Boston Children's Hospital and Harvard Medical School, Boston, MA, United States.
| | - Mitchell C Smith
- Molecular and Behavioral Neuroscience Institute, University of Michigan, Ann Arbor, MI, United States.
| | - Geoffrey G Murphy
- Molecular and Behavioral Neuroscience Institute and Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI, United States.
| | - Hisashi Umemori
- Boston Children's Hospital and Harvard Medical School, Boston, MA, United States; Molecular and Behavioral Neuroscience Institute and Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, United States.
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Pineda JR, Encinas JM. The Contradictory Effects of Neuronal Hyperexcitation on Adult Hippocampal Neurogenesis. Front Neurosci 2016; 10:74. [PMID: 26973452 PMCID: PMC4776215 DOI: 10.3389/fnins.2016.00074] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/17/2016] [Indexed: 01/19/2023] Open
Abstract
Adult hippocampal neurogenesis is a highly plastic process that responds swiftly to neuronal activity. Adult hippocampal neurogenesis can be regulated at the level of neural stem cell recruitment and activation, progenitor proliferation, as well as newborn cell survival and differentiation. An "excitation-neurogenesis" rule was proposed after the demonstration of the capability of cultured neural stem and progenitor cells to intrinsically sense neuronal excitatory activity. In vivo, this property has remained elusive although recently the direct response of neural stem cells to GABA in the hippocampus via GABAA receptors has evidenced a mechanism for a direct talk between neurons and neural stem cells. As it is pro-neurogenic, the effect of excitatory neuronal activity has been generally considered beneficial. But what happens in situations of neuronal hyperactivity in which neurogenesis can be dramatically boosted? In animal models, electroconvulsive shock markedly increases neurogenesis. On the contrary, in epilepsy rodent models, seizures induce the generation of misplaced neurons with abnormal morphological and electrophysiological properties, namely aberrant neurogenesis. We will herein discuss what is known about the mechanisms of influence of neurons on neural stem cells, as well as the severe effects of neuronal hyperexcitation on hippocampal neurogenesis.
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Affiliation(s)
- José R Pineda
- Laboratory of Neural Stem Cells and Neurogenesis, Achucarro Basque Center for Neuroscience Zamudio, Spain
| | - Juan M Encinas
- Laboratory of Neural Stem Cells and Neurogenesis, Achucarro Basque Center for NeuroscienceZamudio, Spain; IKERBASQUE, The Basque Foundation for ScienceBilbao, Spain
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16
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FGF Signaling Is Necessary for Neurogenesis in Young Mice and Sufficient to Reverse Its Decline in Old Mice. J Neurosci 2015; 35:10217-23. [PMID: 26180198 DOI: 10.1523/jneurosci.1469-15.2015] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED The mechanisms regulating hippocampal neurogenesis remain poorly understood. Particularly unclear is the extent to which age-related declines in hippocampal neurogenesis are due to an innate decrease in precursor cell performance or to changes in the environment of these cells. Several extracellular signaling factors that regulate hippocampal neurogenesis have been identified. However, the role of one important family, FGFs, remains uncertain. Although a body of literature suggests that FGFs can promote the proliferation of cultured adult hippocampal precursor cells, their requirement for adult hippocampal neurogenesis in vivo and the cell types within the neurogenic lineage that might depend on FGFs remain unclear. Here, specifically targeting adult neural precursor cells, we conditionally express an activated form of an FGF receptor or delete the FGF receptors that are expressed in these cells. We find that FGF receptors are required for neural stem-cell maintenance and that an activated receptor expressed in all precursors can increase the number of neurons produced. Moreover, in older mice, an activated FGF receptor can rescue the age-related decline in neurogenesis to a level found in young adults. These results suggest that the decrease in neurogenesis with age is not simply due to fewer stem cells, but also to declining signals in their niche. Thus, enhancing FGF signaling in precursors can be used to reverse age-related declines in hippocampal neurogenesis. SIGNIFICANCE STATEMENT Hippocampal deficits can result from trauma, neurodegeneration, or aging and can lead to loss of memory and mood control. The addition of new neurons to the hippocampus facilitates memory formation, but how this process is regulated and how we might manipulate it to reverse hippocampal dysfunction remains unclear. The FGF signaling pathway has been hypothesized to be important, but its role in generating new neurons had been poorly defined. Our study indicates that FGF signaling maintains and expands subsets of neural precursor cells. Moreover, in older mice, increasing FGF signaling is sufficient to reverse the decline in neuron production to levels found in young adults, providing a potential means of reversing age-related hippocampal deficits.
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Paradiso B, Zucchini S, Simonato M. Implication of fibroblast growth factors in epileptogenesis-associated circuit rearrangements. Front Cell Neurosci 2013; 7:152. [PMID: 24062643 PMCID: PMC3772316 DOI: 10.3389/fncel.2013.00152] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 08/26/2013] [Indexed: 12/26/2022] Open
Abstract
The transformation of a normal brain in epileptic (epileptogenesis) is associated with extensive morpho-functional alterations, including cell death, axonal and dendritic plasticity, neurogenesis, and others. Neurotrophic factors (NTFs) appear to be very strongly implicated in these phenomena. In this review, we focus on the involvement of fibroblast growth factor (FGF) family members. Available data demonstrate that the FGFs are highly involved in the generation of the morpho-functional alterations in brain circuitries associated with epileptogenesis. For example, data on FGF2, the most studied member, suggest that it may be implicated both in seizure susceptibility and in seizure-induced plasticity, exerting different, and apparently contrasting effects: favoring acute seizures but reducing seizure-induced cell death. Even if many FGF members are still unexplored and very limited information is available on the FGF receptors, a complex and fascinating picture is emerging: multiple FGFs producing synergic or antagonistic effects one with another (and/or with other NTFs) on biological parameters that, in turn, facilitate or oppose transformation of the normal tissue in epileptic. In principle, identifying key elements in these phenomena may lead to effective therapies, but reaching this goal will require confronting a huge complexity. One first step could be to generate a "neurotrophicome" listing the FGFs (and all other NTFs) that are active during epileptogenesis. This should include identification of the extent to which each NTF is active (concentrations at the site of action); how it is active (local representation of receptor subtypes); when in the natural history of disease this occurs; how the NTF at hand will possibly interact with other NTFs. This is extraordinarily challenging, but holds the promise of a better understanding of epileptogenesis and, at large, of brain function.
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Affiliation(s)
- Beatrice Paradiso
- 1Department of Medical Sciences, Section of Pharmacology, University of Ferrara Ferrara, Italy ; 2Department of Morphology, Surgery and Experimental Medicine, Section of Pathology Ferrara, Italy ; 3National Institute of Neuroscience, University of Ferrara Ferrara, Italy
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18
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Increased excitability in tat-transgenic mice: Role of tat in HIV-related neurological disorders. Neurobiol Dis 2013; 55:110-9. [DOI: 10.1016/j.nbd.2013.02.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 02/03/2013] [Accepted: 02/19/2013] [Indexed: 11/20/2022] Open
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Bradykinin B₂ receptors increase hippocampal excitability and susceptibility to seizures in mice. Neuroscience 2013; 248:392-402. [PMID: 23811399 DOI: 10.1016/j.neuroscience.2013.06.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 06/17/2013] [Accepted: 06/18/2013] [Indexed: 12/23/2022]
Abstract
Bradykinin (BK) and its receptors (B1 and B2) may exert a role in the pathophysiology of certain CNS diseases, including epilepsy. In healthy tissues, B2 receptors are constitutively and widely expressed and B1 receptors are absent or expressed at very low levels, but both receptors, particularly B1, are up-regulated under many pathological conditions. Available data support the notion that up-regulation of B1 receptors in brain areas like the amygdala, hippocampus and entorhinal cortex favors the development and maintenance of an epileptic condition. The role of B2 receptors, instead, is still unclear. In this study, we used two different models to investigate the susceptibility to seizures of B1 knockout (KO) and B2 KO mice. We found that B1 KO are more susceptible to seizures compared with wild-type (WT) mice, and that this may depend on B2 receptors, in that (i) B2 receptors are overexpressed in limbic areas of B1 KO mice, including the hippocampus and the piriform cortex; (ii) hippocampal slices prepared from B1 KO mice are more excitable than those prepared from WT controls, and this phenomenon is B2 receptor-dependent, being abolished by B2 antagonists; (iii) kainate seizure severity is attenuated by pretreatment with a non-peptide B2 antagonist in WT and (more effectively) in B1 KO mice. These data highlight the possibility that B2 receptors may have a role in the responsiveness to epileptogenic insults and/or in the early period of epileptogenesis, that is, in the onset of the molecular and cellular events that lead to the transformation of a normal brain into an epileptic one.
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20
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Directed neuronal differentiation of mouse embryonic and induced pluripotent stem cells and their gene expression profiles. Int J Mol Med 2013; 32:25-34. [PMID: 23652807 DOI: 10.3892/ijmm.2013.1372] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 03/08/2013] [Indexed: 11/05/2022] Open
Abstract
Embryonic stem cells (ESCs) may be useful as a therapeutic source of cells for the production of healthy tissue; however, they are associated with certain challenges including immunorejection as well as ethical issues. Induced pluripotent stem cells (iPSCs) are a promising substitute since a patient's own adult cells would serve as tissue precursors. Ethical concerns prevent a full evaluation of the developmental potency of human ESCs and iPSCs, therefore, mouse iPSC models are required for protocol development and safety assessments. We used a modified culturing protocol to differentiate pluripotent cells from a mouse iPS cell line and two mouse ES cell lines into neurons. Our results indicated that all three pluripotent stem cell lines underwent nearly the same differentiation process when induced to form neurons in vitro. Genomic expression microarray profiling and single-cell RT-qPCR were used to analyze the neural lineage differentiation process, and more than one thousand differentially expressed genes involved in multiple molecular processes relevant to neural development were identified.
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Lee CH, Umemori H. Suppression of epileptogenesis-associated changes in response to seizures in FGF22-deficient mice. Front Cell Neurosci 2013; 7:43. [PMID: 23616746 PMCID: PMC3629311 DOI: 10.3389/fncel.2013.00043] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Accepted: 03/29/2013] [Indexed: 01/20/2023] Open
Abstract
In the developing hippocampus, fibroblast growth factor (FGF) 22 promotes the formation of excitatory presynaptic terminals. Remarkably, FGF22 knockout (KO) mice show resistance to generalized seizures in adults as assessed by chemical kindling, a model that is widely used to study epileptogenesis (Terauchi et al., 2010). Repeated injections of low dose pentylenetetrazol (PTZ) induce generalized seizures ("kindled") in wild type (WT) mice. With additional PTZ injections, FGF22KO mice do show moderate seizures, but they do not kindle. Thus, analyses of how FGF22 impacts seizure susceptibility will contribute to the better understanding of the molecular and cellular mechanisms of epileptogenesis. To decipher the roles of FGF22 in the seizure phenotype, we examine four pathophysiological changes in the hippocampus associated with epileptogenesis: enhancement of dentate neurogenesis, hilar ectopic dentate granule cells (DGCs), increase in hilar cell death, and formation of mossy fiber sprouting (MFS). Dentate neurogenesis is enhanced, hilar ectopic DGCs appeared, and hilar cell death is increased in PTZ-kindled WT mice relative to PBS-injected WT mice. Even in WT mice with fewer PTZ injections, which showed only mild seizures (so were not kindled), neurogenesis, hilar ectopic DGCs, and hilar cell death are increased, suggesting that mild seizures are enough to induce these changes in WT mice. In contrast, PTZ-injected FGF22KO mice do not show these changes despite having moderate seizures: neurogenesis is rather suppressed, hilar ectopic DGCs do not appear, and hilar cell death is unchanged in PTZ-injected FGF22KO mice relative to PBS-injected FGF22KO mice. These results indicate that FGF22 plays important roles in controlling neurogenesis, ectopic migration of DGCs, and hilar cell death after seizures, which may contribute to the generalized seizure-resistant phenotype of FGF22KO mice and suggests a possibility that inhibition of FGF22 may alleviate epileptogenesis.
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Affiliation(s)
- Clara H. Lee
- Molecular and Behavioral Neuroscience Institute, University of Michigan Medical SchoolAnn Arbor, MI, USA
| | - Hisashi Umemori
- Molecular and Behavioral Neuroscience Institute, University of Michigan Medical SchoolAnn Arbor, MI, USA
- Department of Biological Chemistry, University of Michigan Medical SchoolAnn Arbor, MI, USA
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22
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Kwon YS, Pineda E, Auvin S, Shin D, Mazarati A, Sankar R. Neuroprotective and antiepileptogenic effects of combination of anti-inflammatory drugs in the immature brain. J Neuroinflammation 2013; 10:30. [PMID: 23442201 PMCID: PMC3599749 DOI: 10.1186/1742-2094-10-30] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 02/15/2013] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Inflammatory signaling elicited by prolonged seizures can be contributory to neuronal injury as well as adverse plasticity leading to the development of spontaneous recurrent seizures (epilepsy) and associated co-morbidities. In this study, developing rat pups were subjected to lithium-pilocarpine status epilepticus (SE) at 2 and 3 weeks of age to study the effect of anti-inflammatory drugs (AID) on SE-induced hippocampal injury and the development of spontaneous seizures. FINDINGS We selected AIDs directed against interleukin-1 receptors (IL-1ra), a cyclooxygenase-2 (COX-2) inhibitor (CAY 10404), and an antagonist of microglia activation of caspase-1 (minocycline). Acute injury after SE was studied in the 2-week-old rats 24 h after SE. Development of recurrent spontaneous seizures was studied in 3-week-old rats subjected to SE 4 months after the initial insult.None of those AIDs were effective in attenuating CA1 injury in the 2-week-old pups or in limiting the development of spontaneous seizures in 3-week-old pups when administered individually. When empiric binary combinations of these drugs were tried, the combined targeting of IL-1r and COX-2 resulted in attenuation of acute CA1 injury, as determined 24 h after SE, in those animals. The same combination administered for 10 days following SE in 3-week-old rats, reduced the development of spontaneous recurrent seizures and limited the extent of mossy fiber sprouting. CONCLUSIONS Deployment of an empirically designed 'drug cocktail' targeting multiple inflammatory signaling pathways for a limited duration after an initial insult like SE may provide a practical approach to neuroprotection and anti-epileptogenic therapy.
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Affiliation(s)
- Young Se Kwon
- Department of Pediatrics, Division of Neurology, David Geffen School of Medicine at UCLA, 22-474 MDCC in CHS, Los Angeles, CA 90095-1752, USA
- Department of Pediatrics, College of Medicine, Inha University, Incheon, Republic of Korea
| | - Eduardo Pineda
- Department of Pediatrics, Division of Neurology, David Geffen School of Medicine at UCLA, 22-474 MDCC in CHS, Los Angeles, CA 90095-1752, USA
| | - Stéphane Auvin
- Department of Pediatrics, Division of Neurology, David Geffen School of Medicine at UCLA, 22-474 MDCC in CHS, Los Angeles, CA 90095-1752, USA
- Department of Pediatric Neurology, Hôpital Robert Debré, INSERM U676, Paris, 75019, France
| | - Don Shin
- Department of Pediatrics, Division of Neurology, David Geffen School of Medicine at UCLA, 22-474 MDCC in CHS, Los Angeles, CA 90095-1752, USA
| | - Andrey Mazarati
- Department of Pediatrics, Division of Neurology, David Geffen School of Medicine at UCLA, 22-474 MDCC in CHS, Los Angeles, CA 90095-1752, USA
| | - Raman Sankar
- Department of Pediatrics, Division of Neurology, David Geffen School of Medicine at UCLA, 22-474 MDCC in CHS, Los Angeles, CA 90095-1752, USA
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
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Transcriptomic profiling of human peritumoral neocortex tissues revealed genes possibly involved in tumor-induced epilepsy. PLoS One 2013; 8:e56077. [PMID: 23418513 PMCID: PMC3572021 DOI: 10.1371/journal.pone.0056077] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Accepted: 01/09/2013] [Indexed: 12/11/2022] Open
Abstract
The molecular mechanism underlying tumor-induced epileptogenesis is poorly understood. Alterations in the peritumoral microenvironment are believed to play a significant role in inducing epileptogenesis. We hypothesize that the change of gene expression in brain peritumoral tissues may contribute to the increased neuronal excitability and epileptogenesis. To identify the genes possibly involved in tumor-induced epilepsy, a genome-wide gene expression profiling was conducted using Affymetrix HG U133 plus 2.0 arrays and RNAs derived from formalin-fixed paraffin embedded (FFPE) peritumoral cortex tissue slides from 5-seizure vs. 5-non-seizure low grade brain tumor patients. We identified many differentially expressed genes (DEGs). Seven dysregulated genes (i.e., C1QB, CALCRL, CCR1, KAL1, SLC1A2, SSTR1 and TYRO3) were validated by qRT-PCR, which showed a high concordance. Principal Component Analysis (PCA) showed that epilepsy subjects were clustered together tightly (except one sample) and were clearly separated from the non-epilepsy subjects. Molecular functional categorization showed that significant portions of the DEGs functioned as receptor activity, molecular binding including enzyme binding and transcription factor binding. Pathway analysis showed these DEGs were mainly enriched in focal adhesion, ECM-receptor interaction, and cell adhesion molecules pathways. In conclusion, our study showed that dysregulation of gene expression in the peritumoral tissues may be one of the major mechanisms of brain tumor induced-epilepsy. However, due to the small sample size of the present study, further validation study is needed. A deeper characterization on the dysregulated genes involved in brain tumor-induced epilepsy may shed some light on the management of epilepsy due to brain tumors.
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Buzzi A, Chikhladze M, Falcicchia C, Paradiso B, Lanza G, Soukupova M, Marti M, Morari M, Franceschetti S, Simonato M. Loss of cortical GABA terminals in Unverricht–Lundborg disease. Neurobiol Dis 2012; 47:216-24. [DOI: 10.1016/j.nbd.2012.04.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 04/02/2012] [Accepted: 04/08/2012] [Indexed: 11/16/2022] Open
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25
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Chen Y. Organophosphate-induced brain damage: mechanisms, neuropsychiatric and neurological consequences, and potential therapeutic strategies. Neurotoxicology 2012; 33:391-400. [PMID: 22498093 DOI: 10.1016/j.neuro.2012.03.011] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 03/24/2012] [Accepted: 03/25/2012] [Indexed: 02/06/2023]
Abstract
Organophosphate (OP)-induced brain damage is defined as progressive damage to the brain, resulting from the cholinergic neuronal excitotoxicity and dysfunction induced by OP-induced irreversible AChE inhibition. This delayed secondary neuronal damage that occurs mainly in the cholinergic regions of the brain that contain dense accumulations of cholinergic neurons and the majority of cholinergic projection, might be largely responsible for persistent profound neuropsychiatric and neurological impairments (memory, cognitive, mental, emotional, motor and sensory deficits) in the victims of OP poisoning. Neuroprotective strategies for attenuating OP-induced brain damage should target different development stages of OP-induced brain damage, and may include but not limited to: (1) Antidote therapies with atropine and related efficient anticholinergic drugs; (2) Anti-excitotoxic therapies targeting attenuation of cerebral edema and inflammatory reaction, blockage of calcium influx, inhibition of apoptosis program, and the control of seizures; (3) Neuroprotective strategies using cytokines, antioxidants and NMDAR antagonists (a single drug or a combination of drugs) to slow down the process of secondary neuronal damage; and (4) Therapies targeting individual symptoms or clusters of chronic neuropsychiatric and neurological symptoms. These neuroprotective strategies may help limit or prevent secondary neuronal damage at the early stage of OP poisoning and attenuate the subsequent neuropsychiatric and neurological impairments, thus reducing the long-term disability caused by exposure to OPs.
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Affiliation(s)
- Yun Chen
- BrightstarTech, Inc., 23102 Meadow Mist Road, Clarksburg, MD 20871, USA.
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26
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Werner S, Unsicker K, von Bohlen und Halbach O. Fibroblast growth factor-2 deficiency causes defects in adult hippocampal neurogenesis, which are not rescued by exogenous fibroblast growth factor-2. J Neurosci Res 2011; 89:1605-17. [PMID: 21800348 DOI: 10.1002/jnr.22680] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Revised: 03/29/2011] [Accepted: 03/31/2011] [Indexed: 12/17/2022]
Abstract
Neurogenesis within the adult brain is restricted to selected areas, one of which is the dentate gyrus (DG). Several growth factors have been reported to affect neurogenesis in the adult DG. However, a role of fibroblast growth factor-2 (FGF-2) in adult hippocampal neurogenesis has not been firmly established. We have analyzed neurogenesis in the DG using in vivo and in vitro approaches. FGF-2(-/-) mice revealed no alterations in the number of proliferating cells but a significant decrease in the numbers of newly generated neurons. Moreover, FGF-2 added to hippocampal slice cultures from FGF-2(-/-) mice was unable to rescue the phenotype. Although an increase in death of neurogenic cells in the FGF-2-deficient DG could not be specifically demonstrated, there was a massive increase in global cell death in FGF-2(-/-) hippocampal slice cultures compared with slices from wild-type mice. Cell death could not be prevented by addition of FGF-2. Neutralization of endogenous FGF-2 in hippocampal slices did not interfere with neurogenesis in a short-term paradigm. Together, our data suggest that FGF-2 is essentially required for maturation of new neurons in adult hippocampal neurogenesis but is likely to operate synergistically in combination with other mechanisms/growth factors.
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Affiliation(s)
- Sandra Werner
- Interdisciplinary Center for Neurosciences, Department of Neuroanatomy, Heidelberg, Germany.
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27
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Li G, Bauer S, Nowak M, Norwood B, Tackenberg B, Rosenow F, Knake S, Oertel WH, Hamer HM. Cytokines and epilepsy. Seizure 2011; 20:249-56. [PMID: 21216630 DOI: 10.1016/j.seizure.2010.12.005] [Citation(s) in RCA: 181] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 12/02/2010] [Accepted: 12/06/2010] [Indexed: 01/03/2023] Open
Abstract
Epilepsy is a common chronic neurological disorder affecting approximately 8 out of 1000 people. Its pathophysiology, however, has remained elusive in many regards. Consequently, adequate seizure control is still lacking in about one third of patients. Cytokines are soluble mediators of cell communication that are critical in immune regulation. In recent years, studies have shown that epileptic seizures can induce the production of cytokines, which in turn influence the pathogenesis and course of epilepsies. At the time of this review, the focus is mostly on interleukin-1beta (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNFα). In this review, we summarize the current knowledge regarding these cytokines and their potential roles in epilepsy. The focus concentrates on their expression and influence on induced seizures in animal models of epilepsy, as well as findings in human studies. Both proconvulsive and anticonvulsive effects have been reported for each of these molecules. One possible explanation for this phenomenon is that cytokines play dichotomous roles through multiple pathways, each of which is dependent on free concentration and available receptors. Furthermore, the immune-mediated leakage in the blood-brain-barrier also plays an important role in epileptogenesis. Nonetheless, these observations demonstrate the multifarious nature of cytokine networks and the complex relationship between the immune system and epilepsy. Future studies are warranted to further clarify the influence of the immune system on epilepsy and vice versa.
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Affiliation(s)
- Gang Li
- Department of Neurology, University of Marburg, Rudolf-Bultmann-Str. 8, 35033 Marburg, Germany
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28
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Jones K, Basson MA. FGF ligands emerge as potential specifiers of synaptic identity. CELLSCIENCE 2010; 7:33-42. [PMID: 20890457 PMCID: PMC2948530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The central nervous system (CNS) consists of trillions of interconnected neurons. The specialised regions of intercellular contact between neurons where information, usually in chemical form, is transmitted are called synapses. The last decade has seen an unprecedented advance in our understanding of the molecular nature, formation and maintenance of synapses. A major question that remains is how synaptic identity is established to ensure the coordinated recruitment of the correct synaptic components on both sides of the synapse so that the neurotransmitter accumulating on the presynaptic side is matched with its cognate receptor on the postsynaptic membrane. Until recently, Fibroblast Growth Factors (FGFs) have been thought of as general regulators of synaptic aptitude through their ability to increase the expression of synaptic proteins or promote neurite branching. A recent study shows that the decision to form an excitatory vs. inhibitory synapse may to a large extent be determined by the identity of the FGF ligand present at the postsynaptic membrane. This observation establishes FGFs as key target-derived cues that are involved in determining synaptic identity.
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Affiliation(s)
- Kieran Jones
- King's College London, Department of Craniofacial Development and MRC Centre for Developmental Neurobiology, Floor 27, Guy's Tower, London SE1 9RT, UK
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29
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Simonato M, Zucchini S. Are the neurotrophic factors a suitable therapeutic target for the prevention of epileptogenesis? Epilepsia 2010; 51 Suppl 3:48-51. [DOI: 10.1111/j.1528-1167.2010.02609.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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30
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Zechel S, Werner S, Unsicker K, von Bohlen und Halbach O. Expression and Functions of Fibroblast Growth Factor 2 (FGF-2) in Hippocampal Formation. Neuroscientist 2010; 16:357-73. [DOI: 10.1177/1073858410371513] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Among the 23 members of the fibroblast growth factor (FGF) family, FGF-2 is the most abundant one in the central nervous system. Its impact on neural cells has been profoundly investigated by in vitro and in vivo studies as well as by gene knockout analyses during the past 2 decades. Key functions of FGF-2 in the nervous system include roles in neurogenesis, promotion of axonal growth, differentiation in development, and maintenance and plasticity in adulthood. From a clinical perspective, its prominent role for the maintenance of lesioned neurons (e.g., ischemia and following transection of fiber tracts) is of particular relevance. In the unlesioned brain, FGF-2 is involved in synaptic plasticity and processes attributed to learning and memory. The focus of this review is on the expression of FGF-2 and its receptors in the hippocampal formation and the physiological and pathophysiological roles of FGF-2 in this region during development and adulthood.
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Affiliation(s)
- Sabrina Zechel
- Division of Molecular Neurobiology, Department of Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - Sandra Werner
- Department of Molecular Embryology, Institute of Anatomy & Cell Biology, University of Freiburg, Freiburg, Germany
| | - Klaus Unsicker
- Department of Molecular Embryology, Institute of Anatomy & Cell Biology, University of Freiburg, Freiburg, Germany
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31
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Enhancement of GABA(A)-current run-down in the hippocampus occurs at the first spontaneous seizure in a model of temporal lobe epilepsy. Proc Natl Acad Sci U S A 2010; 107:3180-5. [PMID: 20133704 DOI: 10.1073/pnas.0914710107] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Refractory temporal lobe epilepsy (TLE) is associated with a dysfunction of inhibitory signaling mediated by GABA(A) receptors. In particular, the use-dependent decrease (run-down) of the currents (I(GABA)) evoked by the repetitive activation of GABA(A) receptors is markedly enhanced in hippocampal and cortical neurons of TLE patients. Understanding the role of I(GABA) run-down in the disease, and its mechanisms, may allow development of medical alternatives to surgical resection, but such mechanistic insights are difficult to pursue in surgical human tissue. Therefore, we have used an animal model (pilocarpine-treated rats) to identify when and where the increase in I(GABA) run-down occurs in the natural history of epilepsy. We found: (i) that the increased run-down occurs in the hippocampus at the time of the first spontaneous seizure (i.e., when the diagnosis of epilepsy is made), and then extends to the neocortex and remains constant in the course of the disease; (ii) that the phenomenon is strictly correlated with the occurrence of spontaneous seizures, because it is not observed in animals that do not become epileptic. Furthermore, initial exploration of the molecular mechanism disclosed a relative increase in alpha4-, relative to alpha1-containing GABA(A) receptors, occurring at the same time when the increased run-down appears, suggesting that alterations in the molecular composition of the GABA receptors may be responsible for the occurrence of the increased run-down. These observations disclose research opportunities in the field of epileptogenesis that may lead to a better understanding of the mechanism whereby a previously normal tissue becomes epileptic.
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Rabie T, Mühlhofer W, Bruckner T, Schwab A, Bauer AT, Zimmermann M, Bonke D, Marti HH, Schenkel J. Transient protective effect of B-vitamins in experimental epilepsy in the mouse brain. J Mol Neurosci 2009; 41:74-9. [PMID: 19777382 DOI: 10.1007/s12031-009-9286-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Accepted: 08/05/2009] [Indexed: 01/28/2023]
Abstract
The regulation of programmed cell death in the nervous system of vertebrates is a complex mechanism aimed to remove superfluous or damaged cells. Epileptic seizures can lead to an activation of pathways resulting in neuronal cell death. B-vitamins might have a neuroprotective potential reducing cell death following appropriate stimulation. Here, the role of the B-vitamins B(1) (thiamine), B(6) (pyridoxine), and B(12) (cobalamine) was investigated in a mouse model of experimental epilepsy induced by kainate. B-vitamin pre-treated animals showed a significantly reduced epileptic score during the first 15 min after kainate injection. The molecular response to kainate showed a bi-phased time course with early induction of Bcl-2 expression within 12 h and a second induction after 7 days of kainate exposure. B-vitamin pre-treatment resulted in significant higher Bcl-2 expression in control animals (no kainate) and at 12 h within the early phase. Bcl-2 expression was not affected by B-vitamins within the second phase. BAX expression was not significantly influenced during the whole experiment. Three days after kainate stimulation, the number of TdT-mediated dUTP-biotin nick end labeling-positive cells in the hippocampal region was lower in B-vitamin-treated animals. Therefore, B-vitamin pre-treatment may attenuate the response to epileptic stimulation.
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Affiliation(s)
- Tamer Rabie
- Department of Physiology and Pathophysiology, University of Heidelberg Medical School, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
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Localized delivery of fibroblast growth factor-2 and brain-derived neurotrophic factor reduces spontaneous seizures in an epilepsy model. Proc Natl Acad Sci U S A 2009; 106:7191-6. [PMID: 19366663 DOI: 10.1073/pnas.0810710106] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
A loss of neurons is observed in the hippocampus of many patients with epilepsies of temporal lobe origin. It has been hypothesized that damage limitation or repair, for example using neurotrophic factors (NTFs), may prevent the transformation of a normal tissue into epileptic (epileptogenesis). Here, we used viral vectors to locally supplement two NTFs, fibroblast growth factor-2 (FGF-2) and brain-derived neurotrophic factor (BDNF), when epileptogenic damage was already in place. These vectors were first characterized in vitro, where they increased proliferation of neural progenitors and favored their differentiation into neurons, and they were then tested in a model of status epilepticus-induced neurodegeneration and epileptogenesis. When injected in a lesioned hippocampus, FGF-2/BDNF expressing vectors increased neuronogenesis, embanked neuronal damage, and reduced epileptogenesis. It is concluded that reduction of damage reduces epileptogenesis and that supplementing specific NTFs in lesion areas represents a new approach to the therapy of neuronal damage and of its consequences.
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