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3. Microglial glucocorticoid receptors play a pivotal role in regulating dopaminergic neurodegeneration in parkinsonism

Author

Ros-Bernal, Francisco, Hunot, Stéphane, Herrero, Maria Trinidad, Parnadeau, Sebastien, Corvol, Jean-Christophe, Lu, Lixia, Alvarez-Fischer, Daniel, Carrillo-de Sauvage, María Angeles, Saurini, Françoise, Coussieu, Christiane, Kinugawa, Kiyoka, Prigent, Annick, Höglinger, Günter, Hamon, Michel, Tronche, François, Hirsch, Etienne C., Vyas, Sheela, and Gage, Fred H.

Published
2011

6. TLR9 activation via microglial glucocorticoid receptors contributes to degeneration of midbrain dopamine neurons

Author

Maatouk, Layal, Compagnion, Anne-Claire, Sauvage, Maria-Angeles Carrillo-De, Bemelmans, Alexis-Pierre, Leclere-Turbant, Sabrina, Cirotteau, Vincent, Tohmé, Mira, Beke, Allen, Trichet, Michael, Bazin, Virginie, Trawick, Bobby, Ransohoff, Richard, Tronche, Francois, Manoury, Bénédicte, Vyas, Sheela, Neurosciences Paris Seine (NPS), Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Biologie François JACOB (JACOB), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Service MIRCEN (MIRCEN), Université Paris-Saclay-Institut de Biologie François JACOB (JACOB), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Institut de neurosciences translationnelles de Paris (NeurATRIS - IHU-A-ICM), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Institut Necker Enfants-Malades (INEM - UM 111 (UMR 8253 / U1151)), Université Paris Descartes - Paris 5 (UPD5)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Microscopie Electronique [IBPS] (IBPS-ME), Institut de Biologie Paris Seine (IBPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Mallinckrodt Pharmaceuticals, Third Rock Ventures, ANR-13-BSV1-0013,ParkSTRIM,Rôle des altérations du système immunitaire et des fonctions neuronales induites par le stress dans les mécanismes physiopathologiques de la maladie de Parkinson.(2013), Neuroscience Paris Seine (NPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), CHU Pitié-Salpêtrière [APHP], Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie François JACOB (JACOB), Institut du Cerveau = Paris Brain Institute (ICM), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Sorbonne Université (SU)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Sorbonne Université (SU)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Savelli, Bruno, and Blanc 2013 - Rôle des altérations du système immunitaire et des fonctions neuronales induites par le stress dans les mécanismes physiopathologiques de la maladie de Parkinson. - - ParkSTRIM2013 - ANR-13-BSV1-0013 - Blanc 2013 - VALID

Subjects
[SDV] Life Sciences [q-bio], [SDV.IB] Life Sciences [q-bio]/Bioengineering, [SDV]Life Sciences [q-bio], Science, lcsh:Q, [SDV.IB]Life Sciences [q-bio]/Bioengineering, lcsh:Science, ComputingMilieux_MISCELLANEOUS, nervous system diseases
Abstract

Inflammation is a component of Parkinson’s disease. Here the authors show that activation of Toll-like receptor 9 controlled by microglial glucocorticoid receptor signaling, contributes to dopamine neuron loss in a model of Parkinson’s disease.

Published
2018

9. Glucocorticoid receptor in astrocytes regulates midbrain dopamine neurodegeneration through connexin hemichannel activity

Author

Maatouk, Layal, Yi, Chenju, Carrillo-de Sauvage, Maria-Angeles, Compagnion, Anne-Claire, Hunot, Stéphane, Ezan, Pascal, Hirsch, Etienne, Koulakoff, Annette, Pfrieger, Frank, Tronche, Francois, Leybaert, Luc, Giaume, Christian, Vyas, Sheela, Neurosciences Paris Seine (NPS), Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre interdisciplinaire de recherche en biologie (CIRB), Labex MemoLife, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Collège de France (CdF (institution))-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Maladies Neurodégénératives - UMR 9199 (LMN), Centre National de la Recherche Scientifique (CNRS)-Service MIRCEN (MIRCEN), Université Paris-Saclay-Institut de Biologie François JACOB (JACOB), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut de Biologie François JACOB (JACOB), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut du Cerveau et de la Moëlle Epinière = Brain and Spine Institute (ICM), Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut des Neurosciences Cellulaires et Intégratives (INCI), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Universiteit Gent = Ghent University [Belgium] (UGENT), Neuroscience Paris Seine (NPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Collège de France (CdF)-Institut National de la Santé et de la Recherche Médicale (INSERM)-PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Service MIRCEN (MIRCEN), Institut de Biologie François JACOB (JACOB), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [APHP]-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Ghent University [Belgium] (UGENT), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Service MIRCEN (MIRCEN), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie François JACOB (JACOB), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie François JACOB (JACOB), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institut du Cerveau = Paris Brain Institute (ICM), Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Pitié-Salpêtrière [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU)-Sorbonne Université (SU)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Universiteit Gent = Ghent University (UGENT)

Subjects
MICROGLIA, ACTIVATION, PARKINSONS-DISEASE, ALPHA-SYNUCLEIN, INFLAMMATION, CX43 HEMICHANNELS, [SDV]Life Sciences [q-bio], Medicine and Health Sciences, Biology and Life Sciences, MOUSE MODEL, COMMUNICATION, GENE, MECHANISMS
Abstract

International audience; The precise contribution of astrocytes in neuroinflammatory process occurring in Parkinson’s disease (PD) is not well characterized. In this study, using GRCx30CreERT2 mice that are conditionally inactivated for glucocorticoid receptor (GR) in astrocytes, we have examined the actions of astrocytic GR during dopamine neuron (DN) degeneration triggered by the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The results show significantly augmented DN loss in GRCx30CreERT2 mutant mice in substantia nigra (SN) compared to controls. Hypertrophy of microglia but not of astrocytes was greatly enhanced in SN of these astrocytic GR mutants intoxicated with MPTP, indicating heightened microglial reactivity compared to similarly-treated control mice. In the SN of GR astrocyte mutants, specific inflammation-associated transcripts ICAM-1, TNF-α and Il-1β as well as TNF-α protein levels were significantly elevated after MPTP neurotoxicity compared to controls. Interestingly, this paralleled increased connexin hemichannel activity and elevated intracellular calcium levels in astrocytes examined in acute midbrain slices from control and mutant mice treated with MPP+ . The increased connexin-43 hemichannel activity was found in vivo in MPTP-intoxicated mice. Importantly, treatment of MPTP-injected GRCx30CreERT2 mutant mice with TAT-Gap19 peptide, a specific connexin-43 hemichannel blocker, reverted both DN loss and microglial activation; in wild-type mice there was partial but significant survival effect. In the SN of post-mortem PD patients, a significant decrease in the number of astrocytes expressing nuclear GR was observed, suggesting the participation of astrocytic GR deregulation of inflammatory process in PD. Overall, these data provide mechanistic insights into GR-modulated processes in vivo, specifically in astrocytes, that contribute to a pro-inflammatory state and dopamine neurodegeneration in PD pathology.

Published
2018

10. Author Correction: TLR9 activation via microglial glucocorticoid receptors contributes to degeneration of midbrain dopamine neurons

Author

Maatouk, Layal, primary, Compagnion, Anne-Claire, additional, Sauvage, Maria-Angeles Carrillo-de, additional, Bemelmans, Alexis-Pierre, additional, Leclere-Turbant, Sabrina, additional, Cirotteau, Vincent, additional, Tohme, Mira, additional, Beke, Allen, additional, Trichet, Michaël, additional, Bazin, Virginie, additional, Trawick, Bobby N., additional, Ransohoff, Richard M., additional, Tronche, François, additional, Manoury, Bénédicte, additional, and Vyas, Sheela, additional

Published
2018
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14. Caspase-3: A vulnerability factor and final effector in apoptotic death of dopaminergic neurons in Parkinson's disease

Author

Hartmann, Andreas, Hunot, Stephane, Michel, Patrick P., Muriel, Marie-Paule, Vyas, Sheela, Faucheux, Baptiste A., Mouatt-Prigent, Annick, Turmel, Helene, Srinivasan, Anu, Ruberg, Merle, Evan, Gerard I., Agid, Yves, and Hirsh, Etienne C.

Subjects
Cell death -- Analysis, Parkinson's disease -- Research, Dopamine -- Agonists, Brain research -- Research, Science and technology
Abstract

Caspase-3 is an effector of apoptosis in experimental models of Parkinson's disease (PD). However, its potential role in the human pathology remains to be demonstrated. Using caspase-3 immuno-histochemistry on the postmortem human brain, we observed a positive correlation between the degree of neuronal loss in dopaminergic (DA) cell groups affected in the mesencephalon of PD patients and the percentage of caspase-3-positive neurons in these cell groups in control subjects and a significant decrease of caspase-3-positive pigmented neurons in the substantia nigra pars compacta of PD patients compared with controls that also could be observed in an animal model of PD. This suggests that neurons expressing caspase-3 are more sensitive to the pathological process than those that do not express the protein. In addition, using an antibody raised against activated caspase-3, the percentage of active caspase-3-positive neurons among DA neurons was significantly higher in PD patients than in controls. Finally, electron microscopy analysis in the human brain and in vitro data suggest that caspase-3 activation precedes and is not a consequence of apoptotic cell death in PD.

Published
2000

31. Macrophage-Derived Tumor Necrosis Factor α, an Early Developmental Signal for Motoneuron Death.

Author

Sedel, Frédéric, Béchade, Catherine, Vyas, Sheela, and Triller, Antoine

Subjects
TUMOR necrosis factors, MOTOR neurons, CELL death, MACROPHAGES, APOPTOSIS, SOMITE
Abstract

Mechanisms inducing neuronal death at defined times during embryogenesis remain enigmatic. We show in explants that a developmental switch occurs between embryonic day 12 (El2) and El3 in rats that is 72- 48 hr before programmed cell death. Half the motoneurons isolated from peripheral tissues at E12 escape programmed cell death, whereas 90% of motoneurons isolated at El3 enter a death program. The surrounding somite commits El2 motoneurons to death. This effect requires macrophage cells, is mimicked by tumor necrosis factor α (TNFα), and is inhibited by anti-TNFα antibodies. In vivo, TNFα is detected within somite macrophages, and TNF receptor 1 (TNFR 1) is detected within motoneurons precisely between E 12 and E 13. Although motoneuron cell death occurs normally in TNFα-/- mice, this process is significantly reduced in explants from TNFα-/- and TNFR1-/- mice. Thus, embryonic motoneurons acquire the competence to die, before the onset of programmed cell death, from extrinsic signals such as macrophage-derived TNFα. [ABSTRACT FROM AUTHOR]

Published
2004
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36. Chronic stress and glucocorticoid actions in brain plasticity and Tau pathology

Author

Dioli, Chrysoula, Sotiropoulos, I., Vyas, Sheela, Rego, Ana Cristina Carvalho, and Universidade do Minho

Subjects
neurónios, Ciências Médicas::Ciências da Saúde, Ciências da Saúde [Ciências Médicas], glucocorticoid receptor, stress crónico, neurons, microglia, plasticidade cerebral, Tau, receptor de glucocorticoides, brain plasticity, chronic stress
Abstract

Trabalho de Doutoramento realizado em cotutela: Doutoramento em Envelhecimento e Doenças Crónicas e École Doctorale Cerveau, Cognition, Comportement (Paris, no 158), Chronic stress and high levels of the stress hormone, glucocorticoid (GC), are implicated in susceptibility to brain pathologies such as depression or Alzheimer’s disease (AD), as they promote neural plasticity damage and glial reactivity, which can lead to dendritic/synaptic loss, reduced neurogenesis, mood deficits, and impaired cognition. Growing clinical evidence supports a pathological link between depression and AD and shared neurobiological underpinnings with chronic stress being a potential link between them. Exposure of AD animal models to chronic stress triggers Tau pathology (e.g. Tau hyperphosphorylation and accumulation); the latter is causally related to neuronal malfunction and atrophy. Despite the well-known role of Tau in regulating cytoskeletal dynamics, the involvement of Tau in neurostructural remodeling and neuroplastic damage caused by chronic stress in the adult brain remains poorly explored. In the first objective of my thesis, we demonstrated the crucial role of Tau and its malfunction in stress-driven neurogenic, but not astrogliogenic or oligodendrogenic, damage in the cytogenic niches of the adult brain of wild-type animals (hippocampus and subventricular zone-olfactory bulb system) as mice lacking Tau were protected against stress-driven neurogenic suppression. Also, we showed that chronic stress impacts differentially the distinct phases of maturation of newborn immature neurons in the adult hippocampus. The second objective of my thesis focused on the cell-specific actions of the glucocorticoid receptor, GR, in stress-induced Tau pathology. To examine the role of GR specifically in neurons or microglia under stress conditions, we generated P301LTau mice in which GR gene is conditionally inactivated either in forebrain neurons or in microglia. Our findings show that GR was required in both cell types for chronic stress to induce cognitive deficits. Further analyses (which are ongoing) showed that neuronal GR is important in precipitating Tau neuropathology, and apical spine loss in CA1 hippocampal area. Microglial GR was found to affect microglial reactivity both in response to P301LTau as well as chronic stress-induced Tau pathology. Deletion of microglial GR results in spine loss whereas, it promotes spinogenesis under stress. However, it does not appear to impact Tau aggregation/accumulation. In conclusion, our data point to an important role of neuronal GR in mediating stress-driven Tau neuropathology and also identifies the essential role of microglial GR in stress-induced cognitive deficits. Given that the modern lifestyle increasingly exposes individuals to high stress loads, it is clear that understanding the mechanistic link(s) between chronic stress and AD pathogenesis may facilitate the treatment of AD and other related disorders., O stress crónico e as hormonas do stress, glucocorticoides, são sugeridos como causadores de suscetibilidade neuronal, estando associados a danos na plasticidade cerebral (ex. perda dendrítica/sináptica, neurogénese reduzida), inflamação, bem como a distúrbios neurológicos, como depressão e a doença de Alzheimer (DA); onde o dano da neuroplasticidade é um processo muito importante. Evidências clínicas apoiam uma ligação patológica entre a depressão e a DA, e fundamentos neurobiológicos observados no stress crónico indicam que este pode ser um fator de ligação entre elas. A exposição de modelos animais da DA a stress crónico desencadeiam patologia da proteína Tau, que parece estar relacionada com atrofia e o mau funcionamento neuronal. Tendo como função a regulação do citoesqueleto, a proteína Tau tem um papel importante e inexplorado na remodelação neuroestrutural e nos danos neuroplásticos provocados pelo stress crónico. No primeiro objetivo desta Tese, demonstramos a importância da proteína Tau e o impacto do seu mau funcionamento, causado pelo stress, nos nichos citogénicos do cérebro adulto, com impacto na neurogénese, mas não na astrogliogénese ou oligodendrogénese; pois animais sem a proteína Tau são protegidos contra a supressão neurogénica induzida pelo stress crónico. No segundo objetivo, focamo-nos nas ações do receptor de glucocorticoides (GR) na patologia Tau induzida pelo stress, em tipos celulares específicos. Para isso, geramos murganhos P301LTau com deleção condicional de GR em neurónios ou em microglia. Os resultados mostram que o GR é necessário para a indução de danos cognitivos derivados do stress crónico. O GR neuronal é importante para a precipitação da neuropatologia da Tau bem como para a perda de espinhas apicais na zona CA1 do hipocampo. A deleção de GR na microglia levou à sua reatividade, bem como à perda de espinhas, mas com o stress crónico promoveu a sua génese. A mesma não afetou a agregação/acumulação da proteína Tau. Desta forma, concluímos que os nossos dados apontam para o importante papel do GR neuronal na meadiação da neuropatologia da Tau e identificamos o papel essencial do GR na microglia para a indução de danos cognitivos. Dado que o estilo de vida moderno expõe cada vez mais os indivíduos a altas cargas de stress, é clara a necessidade de compreender melhor a ligação entre o stress crónico e a patogénese da DA, facilitando o tratamento da DA e de outros distúrbios., The work presented in this thesis was performed in the Life and Health Sciences Research Institute (ICVS), University of Minho, Portugal and in the Institute of Biology Paris Seine (IBPS), Sorbonne University, France. Financial Support was provided by a Ph.D. fellowship (PD/BD/127825/2016) from the FCT – Foundation for Science and Technology. This Ph.D. has also been funded by National funds, through the Foundation for Science and Technology (FCT) - project UIDB/50026/2020 and UIDP/50026/2020; and by the projects, NORTE-01-0145-FEDER-000013 and NORTE-01-0145-FEDER-000023, the Project Estratégico co-funded by FCT (PEst-C/SAU/LA0026/2013) and the European Regional Development Fund COMPETE (FCOMP-01-0124-FEDER-037298; POCI-01-0145-FEDER-007038) supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). We acknowledge support from PAULIF, a bilateral “Luso-France Integrated Actions” program and to “France Alzheimer et Maladies Apparentées” program.

Published
2021

37. Contribution of glucocorticoids and glucocorticoid receptors to the regulation of neurodegenerative processes.

Author

Vyas S and Maatouk L

Subjects
Animals, Humans, Hypothalamo-Hypophyseal System metabolism, Hypothalamo-Hypophyseal System physiology, Neurodegenerative Diseases psychology, Stress, Psychological metabolism, Stress, Psychological pathology, Glucocorticoids physiology, Neurodegenerative Diseases metabolism, Neurodegenerative Diseases pathology, Receptors, Glucocorticoid physiology
Abstract

Isolation of glucocorticoids (GCs) from adrenal glands followed by synthesis led rapidly to their first clinical application, about 70 years ago, for treatment of rheumatoid arthritis. To this day GCs are used in diseases that have an inflammatory component. However, their use is carefully monitored because of harmful side effects. GCs are also synonymous with stress and adaptation. In CNS, GC binds and activates high affinity mineralocorticoid receptor (MR) and low affinity glucocorticoid receptor (GR). GR, whose expression is ubiquitous, is only activated when GC levels rise as during circadian peak and in response to stress. Numerous recent studies have yielded important and new insights on the mechanisms concerning pulsatile secretory pattern of GCs as well as various processes that tightly control their synthesis via hypothalamic-pituitary-adrenal (HPA) axis involving regulated release of corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH) from hypothalamus and pituitary, respectively. GR modulates neuronal functions and viability through both genomic and non-genomic actions, and importantly its transcriptional regulatory activity is tightly locked with GC secretory pattern. There is increasing evidence pointing to involvement of GC-GR in neurodegenerative disorders. Patients with Alzheimer's or Parkinson's or Huntington's disease show chronically high cortisol levels suggesting changes occurring in controls of HPA axis. In experimental models of these diseases, chronic stress or GC treatment was found to exacerbate both the clinical symptoms and neurodegenerative processes. However, recent evidence also shows that GC-GR can exert neuroprotective effects. Thus, for any potential therapeutic strategies in these neurodegenerative diseases we need to understand the precise modifications both in HPA axis and in GR activity and find ways to harness their protective actions.

Published
2013

38. Macrophage-derived tumor necrosis factor alpha, an early developmental signal for motoneuron death.

Author

Sedel F, Béchade C, Vyas S, and Triller A

Subjects
Animals, Antigens, CD biosynthesis, Apoptosis genetics, Gene Expression Regulation physiology, Mesoderm metabolism, Motor Neurons cytology, RNA, Messenger metabolism, Rats, Rats, Sprague-Dawley, Receptors, Tumor Necrosis Factor biosynthesis, Receptors, Tumor Necrosis Factor, Type I, Somites cytology, Somites physiology, Tumor Necrosis Factor-alpha genetics, Apoptosis physiology, Gene Expression Regulation, Developmental physiology, Macrophages metabolism, Motor Neurons metabolism, Tumor Necrosis Factor-alpha metabolism
Abstract

Mechanisms inducing neuronal death at defined times during embryogenesis remain enigmatic. We show in explants that a developmental switch occurs between embryonic day 12 (E12) and E13 in rats that is 72-48 hr before programmed cell death. Half the motoneurons isolated from peripheral tissues at E12 escape programmed cell death, whereas 90% of motoneurons isolated at E13 enter a death program. The surrounding somite commits E12 motoneurons to death. This effect requires macrophage cells, is mimicked by tumor necrosis factor alpha (TNFalpha), and is inhibited by anti-TNFalpha antibodies. In vivo, TNFalpha is detected within somite macrophages, and TNF receptor 1 (TNFR1) is detected within motoneurons precisely between E12 and E13. Although motoneuron cell death occurs normally in TNFalpha-/- mice, this process is significantly reduced in explants from TNFalpha-/- and TNFR1-/- mice. Thus, embryonic motoneurons acquire the competence to die, before the onset of programmed cell death, from extrinsic signals such as macrophage-derived TNFalpha

Published
2004
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