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1.
Physiol Res ; 67(Supplementum 4): S593-S599, 2018 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-30607966

RESUMO

Mutant Lurcher mice represent an animal model of naturally occurring cerebellar degeneration. A gene mutation causes the demise of all Purkinje cells, as along with certain other types, as well as the functional elimination of the cerebellar cortex. Involvement in the research using this model of the C3H strain began at the Department of Physiology, UCL in 1995/96. It continued in scientific cooperation with other European laboratories where we obtained Lurcher mice of the B6CBA strain. The aim of the effort was first to identify the extent to which the cerebellum is involved in the higher nervous activity, i.e. cognitive and other functions. In that research, use was made of an entire array of methodological procedures to examine learning, memory, motor functions and emotional behavior. It was completed with an electrophysiological examination of the brain and special microscopic procedures. The results demonstrated that the cerebellum (aside from its traditional tasks) does in fact play a significant role in cognitive function, emotions, etc. It was further found that the neurodegenerative processes also affected the immune and endocrine functions, confirming the concept of the unity of the psycho-neuroendocrine-immune system. Surprisingly, despite their neurological impairment, the affected animals were able to learn to some extent and, make progress with physical training, improving not only their motor skills but also learning and memory, including deferring of signs of aging. These particular findings may prove useful for human medicine.


Assuntos
Centros Médicos Acadêmicos/tendências , Cerebelo/patologia , Modelos Animais de Doenças , Degeneração Neural/genética , Degeneração Neural/patologia , Animais , Humanos , Camundongos Endogâmicos C3H , Camundongos Mutantes Neurológicos , Células de Purkinje/patologia , Degenerações Espinocerebelares/genética , Degenerações Espinocerebelares/patologia
2.
Stroke ; 48(12): 3375-3383, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-29146880

RESUMO

BACKGROUND AND PURPOSE: Striatal GABAergic neuron is known as a key regulator in adult neurogenesis. However, the specific role of striatal GABAergic neuronal activity in the promotion of neurological recovery after ischemic stroke remains unknown. Here, we used optogenetic approach to investigate these effects and mechanism. METHODS: Laser stimulation was delivered via an implanted optical fiber to inhibit or activate the striatal GABAergic neurons in Gad2-Arch-GFP or Gad2-ChR2-tdTomato mice (n=80) 1 week after 60-minute transient middle cerebral artery occlusion. Neurological severity score, brain atrophy volume, microvessel density, and cell morphological changes were examined using immunohistochemistry. Gene expression and protein levels of related growth factors were further examined using real-time polymerase chain reaction and Western blotting. RESULTS: Inhibiting striatal GABAergic neuronal activity improved functional recovery, reduced brain atrophy volume, and prohibited cell death compared with the control (P<0.05). Microvessel density and bFGF (basic fibroblast growth factor) expression in the inhibition group were also increased (P<0.05). In contrast, activation of striatal GABAergic neurons resulted in adverse effects compared with the control (P<0.05). Using cocultures of GABAergic neurons, astrocytes, and endothelial cells, we further demonstrated that the photoinhibition of GABAergic neuronal activity could upregulate bFGF expression in endothelial cells, depending on the presence of astrocytes. The conditioned medium from the aforementioned photoinhibited 3-cell coculture system protected cells from oxygen glucose deprivation injury. CONCLUSIONS: After ischemic stroke, optogenetic inhibition of GABAergic neurons upregulated bFGF expression by endothelial cells and promoted neurobehavioral recovery, possibly orchestrated by astrocytes. Optogenetically inhibiting neuronal activity provides a novel approach to promote neurological recovery.


Assuntos
Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/patologia , Corpo Estriado/metabolismo , Antagonistas GABAérgicos/uso terapêutico , Neurônios GABAérgicos/patologia , Optogenética , Animais , Isquemia Encefálica/metabolismo , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Fator 2 de Crescimento de Fibroblastos/biossíntese , Lasers , Masculino , Camundongos , Camundongos Mutantes Neurológicos , Artéria Cerebral Média/patologia , Recuperação de Função Fisiológica , Ácido gama-Aminobutírico/metabolismo
3.
Neuroreport ; 28(18): 1255-1260, 2017 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-29099440

RESUMO

Absence seizures are known to originate from disruptions within the corticothalamocortical network; however, the precise underlying cellular and molecular mechanisms that induce hypersynchronicity and hyperexcitability are debated and likely to be complex and multifactorial. Recent studies implicate impaired thalamic GABAergic inhibition as a common feature in multiple animal models of absence epilepsy, including the well-established stargazer mouse model. Recently, we demonstrated region-specific increases in the whole tissue and synaptic levels of GABAA receptor (GABAAR) subunits α1 and ß2, within the ventral posterior region of the thalamus in adult epileptic stargazer mice compared with nonepileptic control littermates. The objective of this study was to investigate whether such changes in GABAAR subunits α1 and ß2 can be observed before the initiation of seizures, which occur around postnatal (PN) days 16-18 in stargazers. Semiquantitative western blotting was used to analyze the relative tissue level expression of GABAAR α1 and ß2 subunits in the thalamus of juvenile stargazer mice compared with their nonepileptic control littermates at three different time points before the initiation of seizures. We show that there is a statistically significant increase in the expression of α1 and ß2 subunits in the thalamus of stargazer mice, at the PN7-9 stage, compared with the control littermates, but not at PN10-12 and PN13-15 stages. These results suggest that an aberrant expression of GABAAR subunits α1 and ß2 in the stargazers does not occur immediately before seizure onset and therefore is unlikely to directly contribute to the initiation of absence seizures.


Assuntos
Canais de Cálcio/genética , Epilepsia Tipo Ausência , Mutação/genética , Receptores de GABA-A/metabolismo , Tálamo/metabolismo , Fatores Etários , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Epilepsia Tipo Ausência/genética , Epilepsia Tipo Ausência/metabolismo , Epilepsia Tipo Ausência/patologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Camundongos , Camundongos Mutantes Neurológicos , Subunidades Proteicas/metabolismo , Tálamo/crescimento & desenvolvimento
4.
J Neurosci ; 37(41): 9844-9858, 2017 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-28887386

RESUMO

Fragile X mental retardation protein (FMRP) loss causes Fragile X syndrome (FXS), a major disorder characterized by autism, intellectual disability, hyperactivity, and seizures. FMRP is both an RNA- and channel-binding regulator, with critical roles in neural circuit formation and function. However, it remains unclear how these FMRP activities relate to each other and how dysfunction in their absence underlies FXS neurological symptoms. In testing circuit level defects in the Drosophila FXS model, we discovered a completely unexpected and highly robust neuronal dye iontophoresis phenotype in the well mapped giant fiber (GF) circuit. Controlled dye injection into the GF interneuron results in a dramatic increase in dye uptake in neurons lacking FMRP. Transgenic wild-type FMRP reintroduction rescues the mutant defect, demonstrating a specific FMRP requirement. This phenotype affects only small dyes, but is independent of dye charge polarity. Surprisingly, the elevated dye iontophoresis persists in shaking B mutants that eliminate gap junctions and dye coupling among GF circuit neurons. We therefore used a wide range of manipulations to investigate the dye uptake defect, including timed injection series, pharmacology and ion replacement, and optogenetic activity studies. The results show that FMRP strongly limits the rate of dye entry via a cytosolic mechanism. This study reveals an unexpected new phenotype in a physical property of central neurons lacking FMRP that could underlie aspects of FXS disruption of neural function.SIGNIFICANCE STATEMENT FXS is a leading heritable cause of intellectual disability and autism spectrum disorders. Although researchers established the causal link with FMRP loss >;25 years ago, studies continue to reveal diverse FMRP functions. The Drosophila FXS model is key to discovering new FMRP roles, because of its genetic malleability and individually identified neuron maps. Taking advantage of a well characterized Drosophila neural circuit, we discovered that neurons lacking FMRP take up dramatically more current-injected small dye. After examining many neuronal properties, we determined that this dye defect is cytoplasmic and occurs due to a highly elevated dye iontophoresis rate. We also report several new factors affecting neuron dye uptake. Understanding how FMRP regulates iontophoresis should reveal new molecular factors underpinning FXS dysfunction.


Assuntos
Sistema Nervoso Central/metabolismo , Proteína do X Frágil de Retardo Mental/metabolismo , Neurônios/metabolismo , Animais , Sistema Nervoso Central/citologia , Corantes , Dendritos/metabolismo , Drosophila , Proteína do X Frágil de Retardo Mental/genética , Junções Comunicantes/metabolismo , Interneurônios/metabolismo , Iontoforese , Camundongos , Camundongos Mutantes Neurológicos , Optogenética
5.
Nucleic Acids Res ; 45(16): 9514-9527, 2017 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-28934484

RESUMO

The Human antigen R protein (HuR) is an RNA-binding protein that recognizes U/AU-rich elements in diverse RNAs through two RNA-recognition motifs, RRM1 and RRM2, and post-transcriptionally regulates the fate of target RNAs. The natural product dihydrotanshinone-I (DHTS) prevents the association of HuR and target RNAs in vitro and in cultured cells by interfering with the binding of HuR to RNA. Here, we report the structural determinants of the interaction between DHTS and HuR and the impact of DHTS on HuR binding to target mRNAs transcriptome-wide. NMR titration and Molecular Dynamics simulation identified the residues within RRM1 and RRM2 responsible for the interaction between DHTS and HuR. RNA Electromobility Shifts and Alpha Screen Assays showed that DHTS interacts with HuR through the same binding regions as target RNAs, stabilizing HuR in a locked conformation that hampers RNA binding competitively. HuR ribonucleoprotein immunoprecipitation followed by microarray (RIP-chip) analysis showed that DHTS treatment of HeLa cells paradoxically enriched HuR binding to mRNAs with longer 3'UTR and with higher density of U/AU-rich elements, suggesting that DHTS inhibits the association of HuR to weaker target mRNAs. In vivo, DHTS potently inhibited xenograft tumor growth in a HuR-dependent model without systemic toxicity.


Assuntos
Proteína Semelhante a ELAV 1/química , Fenantrenos/química , Fenantrenos/farmacologia , Regiões 3' não Traduzidas , Elementos Ricos em Adenilato e Uridilato , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Proteína Semelhante a ELAV 1/antagonistas & inibidores , Proteína Semelhante a ELAV 1/genética , Proteína Semelhante a ELAV 1/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Camundongos Mutantes Neurológicos , Simulação de Dinâmica Molecular , Fenantrenos/metabolismo , Mutação Puntual , Conformação Proteica , Domínios Proteicos , RNA Mensageiro/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
6.
J Neuroimmunol ; 311: 59-67, 2017 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-28807491

RESUMO

Autism is a complex heterogeneous neurodevelopmental disorder; previous studies have identified altered immune responses among individuals diagnosed with autism. An imbalance in the production of pro- and anti-inflammatory cytokines and transcription factors plays a role in neurodevelopmental behavioral and autism disorders. BTBR T+ Itpr3tf/J (BTBR) mice are used as a model for autism, as they exhibit social deficits, communication deficits, and repetitive behaviors compared with C57BL/6J (B6) mice. The adenosine A2A receptor (A2AR) appears to be a potential target for the improvement of behavioral, inflammatory, immune, and neurological disorders. We investigated the effects of the A2AR antagonist SCH 5826 (SCH) and agonist CGS 21680 (CGS) on IL-21, IL-22, T-bet, T-box transcription factor (T-bet), GATA3 (GATA Binding Protein 3), and CD152 (CTLA-4) expression in BTBR mice. Our results showed that BTBR mice treated with SCH had increased CD4+IL-21+, CD4+IL-22+, CD4+GATA3+, and CD4+T-bet+ and decreased CD4+CTLA-4+ expression in spleen cells compared with BTBR control mice. Moreover, CGS efficiently decreased CD4+IL-21+, CD4+IL-22+, CD4+GATA3+, and CD4+T-bet+ and increased CD4+CTLA-4 production in spleen cells compared with SCH-treated and BTBR control mice. Additionally, SCH treatment significantly increased the mRNA and protein expression levels of IL-21, IL-22, GATA3, and T-bet in brain tissue compared with CGS-treated and BTBR control mice. The augmented levels of IL-21/IL-22 and GATA3/T-bet could be due to altered A2AR signaling. Our results indicate that A2AR agonists may represent a new class of compounds that can be developed for use in the treatment of autistic and neuroimmune dysfunctions.


Assuntos
Transtorno Autístico/patologia , Linfócitos T CD4-Positivos/metabolismo , Citocinas/metabolismo , Fator de Transcrição GATA3/metabolismo , Receptor A2A de Adenosina/metabolismo , Transdução de Sinais/genética , Adenosina/análogos & derivados , Adenosina/farmacologia , Agonistas do Receptor A2 de Adenosina/farmacologia , Antagonistas do Receptor A2 de Adenosina/farmacologia , Animais , Transtorno Autístico/genética , Transtorno Autístico/imunologia , Encéfalo/metabolismo , Linfócitos T CD4-Positivos/efeitos dos fármacos , Modelos Animais de Doenças , Proteínas Fetais/genética , Proteínas Fetais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Receptores de Inositol 1,4,5-Trifosfato/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes Neurológicos , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Fenetilaminas/farmacologia , Pirimidinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Baço/patologia , Proteínas com Domínio T/genética , Proteínas com Domínio T/metabolismo , Triazóis/farmacologia
7.
Rev Neurol ; 64(s03): S19-S24, 2017 May 17.
Artigo em Espanhol | MEDLINE | ID: mdl-28524214

RESUMO

The new treatments of spinal muscular atrophy (SMA) due by SMN1 gene deletions are reviewed. There are several ways to increase the protein SMN, its activity and persistence in the tissues. Neuroprotective drugs as olesoxime or riluzole, and drugs acting by epigenetic mechanisms, as histone deacetylase inhibitors, have shown positive effects in preclinical studies but no clear efficacy in clinical trials. They might give in the future added benefits when used associated to other genetic modifying drugs. The best improvements in murine models of SMA and in clinical trials have been reached with antisense oligonucleotides, drugs that modify the splicing of SMN2, and they are expected to get better in the near future. Nusinersen, a methoxi-ethyl phosphotioate antisense oligonucleotide has recently approved for treatment of patients with SMA type 1 after having proved its efficacy in clinical trial phase 3. The results of nusinersen are reviewed. New modifications of antisense oligonucleotides with better access to brain, spinal cord and peripheral tissues are on the way. There are data of the efficacy of the genetic therapy with SMN1 gene through adenoassociated virus, now in phase 1 trial. A constant feature of these new treatments is that the earlier the treatment, the best are the results, and they are even better in presymptomatic stage. The general standards of care, particularly nutrition and respiratory management are needed in order to reach optimal results with the new therapies.


Assuntos
Atrofias Musculares Espinais da Infância/terapia , Terapias em Estudo , Animais , Criança , Ensaios Clínicos como Assunto , Dependovirus/genética , Modelos Animais de Doenças , Epigênese Genética , Deleção de Genes , Terapia Genética , Vetores Genéticos/uso terapêutico , Inibidores de Histona Desacetilases/uso terapêutico , Humanos , Camundongos , Camundongos Mutantes Neurológicos , Estudos Multicêntricos como Assunto , Fármacos Neuroprotetores/uso terapêutico , Oligonucleotídeos/uso terapêutico , Oligonucleotídeos Antissenso/uso terapêutico , Cuidados Paliativos , Células-Tronco Pluripotentes/transplante , Processamento de RNA , Proteínas Recombinantes/genética , Atrofias Musculares Espinais da Infância/genética , Proteína 1 de Sobrevivência do Neurônio Motor/biossíntese , Proteína 1 de Sobrevivência do Neurônio Motor/genética , Proteína 2 de Sobrevivência do Neurônio Motor/biossíntese , Proteína 2 de Sobrevivência do Neurônio Motor/genética
8.
Neurodegener Dis ; 17(4-5): 181-198, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28490024

RESUMO

BACKGROUND/AIMS: A novel ataxic mouse line was established from the offspring of a male mouse administered cyclophosphamide in a juvenile period. METHODS: We have attempted to examine the phenotype and histopathological changes of affected mice. Furthermore, linkage analysis and sequencing of the mutant was performed to reveal the causative gene locus. RESULTS AND CONCLUSION: The affected mouse was characterized by heavy hind limb ataxia with gait disorder, which was first recognized at about 4 weeks of age and slowly progressed with advancing age. The phenotype was inherited in an autosomal recessive pattern. The genetic locus associated with the phenotype was named hak and mapped to 107,305,356-108,637,615 on chromosome 2qE3, non-coding sequences in the vicinity of Bdnf gene. Many spheroids were noticed in the cerebellar medulla and the brain stem. In the peripheral nerves, some sensory ganglionic cells showed deposition of NF-200 in the perikaryon and NF-200-positive spheroids in nerve fibers. No inflammatory cell infiltration was observed. In addition, the adult affected mouse had distinct iron deposition in the kidney and the liver, but not in the heart, the skeletal muscle and the central nervous system. These results suggest that the hak mouse has a tissue-specific impairment in the expression of a type of Bdnf transcripts.


Assuntos
Ataxia , Fator Neurotrófico Derivado do Encéfalo/genética , Modelos Animais de Doenças , Íons Pesados , Rim/metabolismo , Doenças do Sistema Nervoso Periférico/etiologia , Animais , Ataxia/induzido quimicamente , Ataxia/complicações , Ataxia/genética , Ataxia/patologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Calbindinas/metabolismo , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/patologia , Mapeamento Cromossômico , Ciclofosfamida/toxicidade , Progressão da Doença , Feminino , Estudo de Associação Genômica Ampla , Imunossupressores/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Camundongos Mutantes Neurológicos , Proteínas de Neurofilamentos/metabolismo
9.
Neuropharmacology ; 121: 140-157, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28461162

RESUMO

Neurotrophic factors are among the most promising treatments aiming at slowing or stopping and even reversing Parkinson's disease (PD). However, in most cases, they cannot readily cross the human blood-brain-barrier (BBB). Herein, we propose as a therapeutic for PD the small molecule 17-beta-spiro-[5-androsten-17,2'-oxiran]-3beta-ol (BNN-20), a synthetic analogue of DHEA, which crosses the BBB and is deprived of endocrine side-effects. Using the "weaver" mouse, a genetic model of PD, which exhibits progressive dopaminergic neurodegeneration in the Substantia Nigra (SN), we have shown that long-term administration (P1-P21) of BNN-20 almost fully protected the dopaminergic neurons and their terminals, via i) a strong anti-apoptotic effect, probably mediated through the Tropomyosin receptor kinase B (TrkB) neurotrophin receptor's PI3K-Akt-NF-κB signaling pathway, ii) by exerting an efficient antioxidant effect, iii) by inducing significant anti-inflammatory activity and iv) by restoring Brain-Derived Neurotrophic Factor (BDNF) levels. By intercrossing "weaver" with NGL mice (dual GFP/luciferase-NF-κΒ reporter mice, NF-κΒ.GFP.Luc), we obtained Weaver/NGL mice that express the NF-κB reporter in all somatic cells. Acute BNN-20 administration to Weaver/NGL mice induced a strong NF-κB-dependent transcriptional response in the brain as detected by bioluminescence imaging, which was abolished by co-administration of the TrkB inhibitor ANA-12. This indicates that BNN-20 exerts its beneficial action (at least in part) through the TrkB-PI3K-Akt-NF-κB signaling pathway. These results could be of clinical relevance, as they suggest BNN-20 as an important neuroprotective agent acting through the TrkB neurotrophin receptor pathway, mimicking the action of the endogenous neurotrophin BDNF. Thus BNN-20 could be proposed for treatment of PD.


Assuntos
Desidroepiandrosterona/análogos & derivados , Dopamina/metabolismo , Neurônios Dopaminérgicos/efeitos dos fármacos , Mesencéfalo/citologia , Receptor trkB/metabolismo , Adjuvantes Imunológicos/farmacologia , Animais , Animais Recém-Nascidos , Antígenos CD1/metabolismo , Azepinas/farmacologia , Benzamidas/farmacologia , Células CHO , Cricetulus , Desidroepiandrosterona/farmacologia , Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Feminino , Masculino , Mesencéfalo/efeitos dos fármacos , Mesencéfalo/metabolismo , Camundongos , Camundongos Mutantes Neurológicos , Modelos Genéticos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Tubulina (Proteína)/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo
10.
J Neurochem ; 142(1): 103-117, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28382685

RESUMO

Multiple sclerosis (MS) is considered a primary autoimmune disease; however, this view is increasingly being challenged in basic and clinical science arenas because of the growing body of clinical trials' data showing that exclusion of immune cells from the CNS only modestly slows disease progression to disability. Accordingly, there is significant need for expanding the scope of potential disease mechanisms to understand the etiology of MS. Concomitantly, the use of a broader range of pre-clinical animal models for characterizing existing efficacious clinical treatments may elucidate additional or unexpected mechanisms of action for these drugs that augment insight into MS etiology. Herein, we explore the in vivo mechanism of action of dimethyl fumarate, which has been shown to suppress oxidative stress and immune cell responses in psoriasis and MS. Rather than studying this compound in the context of an experimental autoimmune-induced attack on the CNS, we have used a genetic model of hypomyelination, male rumpshaker (rsh) mice, which exhibit oligodendrocyte metabolic stress and startle-induced subcortical myoclonus during development and into adulthood. We find that myoclonus is reduced 30-50% in treated mutants but we do not detect substantial changes in metabolic or oxidative stress response pathways, cytokine modulation, or myelin thickness (assessed by anova). All procedures involving vertebrate animals in this study were reviewed and approved by the IACUC committee at Wayne State University.


Assuntos
Fumarato de Dimetilo/farmacologia , Mioclonia/genética , Mioclonia/prevenção & controle , Fármacos Neuroprotetores/farmacologia , Oligodendroglia/patologia , Deficiências na Proteostase/genética , Deficiências na Proteostase/patologia , Animais , Citocinas/metabolismo , Eletrodos Implantados , Masculino , Camundongos , Camundongos Mutantes Neurológicos , Bainha de Mielina/patologia , Mioclonia/patologia , Fator 2 Relacionado a NF-E2/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/genética , Nervo Óptico/patologia , Estresse Oxidativo/genética , Equilíbrio Postural , Deficiências na Proteostase/prevenção & controle , Reflexo de Sobressalto
11.
Neuron ; 93(6): 1344-1358.e5, 2017 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-28285824

RESUMO

The Reelin signaling pathway plays a crucial role in regulating neocortical development. However, little is known about how Reelin controls the cytoskeleton during neuronal migration. Here, we identify CLASP2 as a key cytoskeletal effector in the Reelin signaling pathway. We demonstrate that CLASP2 has distinct roles during neocortical development regulating neuron production and controlling neuron migration, polarity, and morphogenesis. We found downregulation of CLASP2 in migrating neurons leads to mislocalized cells in deeper cortical layers, abnormal positioning of the centrosome-Golgi complex, and aberrant length/orientation of the leading process. We discovered that Reelin regulates several phosphorylation sites within the positively charged serine/arginine-rich region that constitute consensus GSK3ß phosphorylation motifs of CLASP2. Furthermore, phosphorylation of CLASP2 regulates its interaction with the Reelin adaptor Dab1 and this association is required for CLASP2 effects on neurite extension and motility. Together, our data reveal that CLASP2 is an essential Reelin effector orchestrating cytoskeleton dynamics during brain development.


Assuntos
Moléculas de Adesão Celular Neuronais/metabolismo , Citoesqueleto/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Associadas aos Microtúbulos/fisiologia , Neocórtex/crescimento & desenvolvimento , Proteínas do Tecido Nervoso/metabolismo , Neurogênese/fisiologia , Serina Endopeptidases/metabolismo , Animais , Movimento Celular/fisiologia , Regulação para Baixo , Feminino , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Masculino , Camundongos , Camundongos Knockout , Camundongos Mutantes Neurológicos , Neocórtex/fisiologia , Proteínas do Tecido Nervoso/genética , Neuritos/fisiologia , Neurônios/metabolismo , Fosforilação , Cultura Primária de Células
12.
Adv Exp Med Biol ; 974: 97-114, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28353227

RESUMO

Modelling psychiatric disorders in animals has been hindered by several challenges related to our poor understanding of the disease causes. This chapter describes recent advances in translational research which may lead to animal models and relevant proteomic biomarkers that can be informative about disease mechanisms and potential new therapeutic targets. The review focuses on the behavioural and molecular correlates in models of schizophrenia and major depressive disorder, as guided by recently established Research Domain Criteria (RDoC). This approach is based on providing proteomic data for aetiologically driven, behaviourally well-characterised animal models to link discovered biomarker candidates with the human disease.


Assuntos
Biomarcadores/análise , Química Encefálica , Modelos Animais de Doenças , Etologia/métodos , Transtornos Mentais/metabolismo , Proteínas do Tecido Nervoso/análise , Neurociências/métodos , Proteômica/métodos , Pesquisa Médica Translacional/métodos , Animais , Comportamento Animal/fisiologia , Descoberta de Drogas , Humanos , Transtornos Mentais/induzido quimicamente , Transtornos Mentais/tratamento farmacológico , Transtornos Mentais/etiologia , Camundongos , Camundongos Mutantes Neurológicos , Proteínas do Tecido Nervoso/genética , Doenças do Sistema Nervoso/induzido quimicamente , Doenças do Sistema Nervoso/genética , Doenças do Sistema Nervoso/psicologia , Primatas , Psicotrópicos/farmacologia , Ratos , Especificidade da Espécie
13.
Neurobiol Learn Mem ; 140: 62-70, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28213063

RESUMO

Both humans and laboratory animals suffering from cerebellar lesions exhibit cognitive as well as many emotional and behavioral abnormalities. These latter have been already observed in the cerebellar mutant mice currently used to highlight some aspect of autism spectrum disorders. The aim of this study was to investigate the influence of cerebellar-related stress response abnormalities on spatial learning and memory. Cerebellar-deficient Lurcher mutant mice were exposed to water environment without active escape possibility and then tested for spatial learning in the Morris water maze. As a marker of stress intensity we measured corticosterone in urine. Finally, the volumes of individual components of the adrenal gland were estimated. Though having spatial navigation deficit in the water maze, Lurcher mice preserved a substantial residuum of learning capacity. Lurcher mutants had a higher increase of corticosterone level after exposure to the water environment than wild type mice. We did not observe any decrease of this physiological stress marker between the start and the end of the spatial navigation task, despite significant improvement of behavioral performances. Furthermore, zona fasciculata and zona reticularis of the adrenal cortex as well as the adrenal medulla were larger in Lurcher mice, reflecting high stress reactivity. We conclude that for both genotypes water exposure was a strong stressor and that there was no habituation to the experiment independently to the increasing controllability of the stressor (e.g. ability to find the escape platform). Based on these findings, we suggest that the enhanced stress response to water exposure is not the main factor explaining the spatial deficits in these cerebellar mutant mice.


Assuntos
Glândulas Suprarrenais/patologia , Corticosterona/urina , Percepção Espacial/fisiologia , Navegação Espacial/fisiologia , Estresse Fisiológico/fisiologia , Animais , Masculino , Camundongos , Camundongos Mutantes Neurológicos , Tamanho do Órgão/fisiologia
14.
Brain Pathol ; 27(4): 459-471, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-27488538

RESUMO

Motor neuron diseases such as amyotrophic lateral sclerosis (ALS) are now recognized as multi-system disorders also involving various non-motor neuronal cell types. The precise extent and mechanistic basis of non-motor neuron damage in human ALS and ALS animal models remain however unclear. To address this, we here studied progressive motor neuronopathy (pmn) mice carrying a missense loss-of-function mutation in tubulin binding cofactor E (TBCE). These mice manifest a particularly aggressive form of motor axon dying back and display a microtubule loss, similar to that induced by human ALS-linked TUBA4A mutations. Using whole nerve confocal imaging of pmn × thy1.2-YFP16 fluorescent reporter mice and electron microscopy, we demonstrate axonal discontinuities, bead-like spheroids and ovoids in pmn suralis nerves indicating prominent sensory neuropathy. The axonal alterations qualitatively resemble those in phrenic motor nerves but do not culminate in the loss of myelinated fibers. We further show that the pmn mutation decreases the level of TBCE, impedes microtubule polymerization in dorsal root ganglion (DRG) neurons and causes progressive loss of microtubules in large and small caliber suralis axons. Live imaging of axonal transport using GFP-tagged tetanus toxin C-fragment (GFP-TTC) demonstrates defects in microtubule-based transport in pmn DRG neurons, providing a potential explanation for the axonal alterations in sensory nerves. This study unravels sensory neuropathy as a pathological feature of mouse pmn, and discusses the potential contribution of cytoskeletal defects to sensory neuropathy in human motor neuron disease.


Assuntos
Transporte Axonal/genética , Microtúbulos/metabolismo , Doença dos Neurônios Motores/complicações , Doenças do Sistema Nervoso Periférico/etiologia , Doenças do Sistema Nervoso Periférico/patologia , Nervo Sural/patologia , Animais , Axônios/metabolismo , Axônios/patologia , Células Cultivadas , Modelos Animais de Doenças , Embrião de Mamíferos , Gânglios Espinais/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes Neurológicos , Camundongos Transgênicos , Microtúbulos/genética , Microtúbulos/ultraestrutura , Chaperonas Moleculares/genética , Doença dos Neurônios Motores/genética , Doença dos Neurônios Motores/patologia , Mutação de Sentido Incorreto/genética , Neurônios/metabolismo , Neurônios/patologia , Neurônios/ultraestrutura , Nervo Frênico/patologia , Nervo Frênico/ultraestrutura , Polimerização , Nervo Sural/metabolismo , Nervo Sural/ultraestrutura
15.
Neuroscience ; 345: 99-109, 2017 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-27012612

RESUMO

Cognitive flexibility has traditionally been considered a frontal lobe function. However, converging evidence suggests involvement of a larger brain circuit which includes the cerebellum. Reciprocal pathways connecting the cerebellum to the prefrontal cortex provide a biological substrate through which the cerebellum may modulate higher cognitive functions, and it has been observed that cognitive inflexibility and cerebellar pathology co-occur in psychiatric disorders (e.g., autism, schizophrenia, addiction). However, the degree to which the cerebellum contributes to distinct forms of cognitive flexibility and rule learning is unknown. We tested lurcher↔wildtype aggregation chimeras which lose 0-100% of cerebellar Purkinje cells during development on a touchscreen-mediated attentional set-shifting task to assess the contribution of the cerebellum to higher and lower order rule learning and cognitive flexibility. Purkinje cells, the sole output of the cerebellar cortex, ranged from 0 to 108,390 in tested mice. Reversal learning and extradimensional set-shifting were impaired in mice with⩾95% Purkinje cell loss. Cognitive deficits were unrelated to motor deficits in ataxic mice. Acquisition of a simple visual discrimination and an attentional-set were unrelated to Purkinje cells. A positive relationship was observed between Purkinje cells and errors when exemplars from a novel, non-relevant dimension were introduced. Collectively, these data suggest that the cerebellum contributes to higher order cognitive flexibility, lower order cognitive flexibility, and attention to novel stimuli, but not the acquisition of higher and lower order rules. These data indicate that the cerebellar pathology observed in psychiatric disorders may underlie deficits involving cognitive flexibility and attention to novel stimuli.


Assuntos
Cerebelo/fisiologia , Função Executiva/fisiologia , Reversão de Aprendizagem/fisiologia , Análise de Variância , Animais , Ataxia/patologia , Ataxia/fisiopatologia , Atenção/fisiologia , Cerebelo/patologia , Cerebelo/fisiopatologia , Quimera , Cognição , Transtornos Cognitivos/patologia , Transtornos Cognitivos/fisiopatologia , Camundongos Mutantes Neurológicos , Testes Neuropsicológicos , Tempo de Reação , Recompensa
16.
Cerebellum ; 16(1): 40-54, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-26837618

RESUMO

Autism spectrum disorders (ASDs) are a group of neurodevelopmental disorders characterized by impaired and disordered language, decreased social interactions, stereotyped and repetitive behaviors, and impaired fine and gross motor skills. It has been well established that cerebellar abnormalities are one of the most common structural changes seen in the brains of people diagnosed with autism. Common cerebellar pathology observed in autistic individuals includes variable loss of cerebellar Purkinje cells (PCs) and increased numbers of reactive neuroglia in the cerebellum and cortical brain regions. The Lc/+ mutant mouse loses 100 % of cerebellar PCs during the first few weeks of life and provided a valuable model to study the effects of developmental PC loss on underlying structural and functional changes in cerebellar neural circuits. Lurcher (Lc) chimeric mice were also generated to explore the link between variable cerebellar pathology and subsequent changes in the structure and function of cerebellar neurons and neuroglia. Chimeras with the most severe cerebellar pathology (as quantified by cerebellar PC counts) had the largest changes in cFos expression (an indirect reporter of neural activity) in cerebellar granule cells (GCs) and cerebellar nucleus (CN) neurons. In addition, Lc chimeras with the fewest PCs also had numerous reactive microglia and Bergmann glia located in the cerebellar cortex. Structural and functional abnormalities observed in the cerebella of Lc chimeras appeared to be along a continuum, with the degree of pathology related to the number of PCs in individual chimeras.


Assuntos
Cerebelo/patologia , Neuroglia/patologia , Neurônios/patologia , Animais , Transtorno do Espectro Autista , Morte Celular , Cerebelo/metabolismo , Quimera , Feminino , Expressão Gênica , Gliose/metabolismo , Gliose/patologia , Imuno-Histoquímica , Masculino , Camundongos Mutantes Neurológicos , Atividade Motora/fisiologia , Vias Neurais/metabolismo , Vias Neurais/patologia , Neuroglia/metabolismo , Neurônios/metabolismo , Proteínas Proto-Oncogênicas c-fos/metabolismo , Teste de Desempenho do Rota-Rod , Índice de Gravidade de Doença
17.
Neurobiol Dis ; 96: 271-283, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27693510

RESUMO

We identified a novel spontaneous mutant mouse showing motor symptoms that are similar to those of the dystonia musculorum (dt) mouse. The observations suggested that the mutant mice inherited the mild dt phenotype as an autosomal recessive trait. Linkage analysis showed that the causative gene was located near D1Mit373 and D1Mit410 microsatellite markers on chromosome 1, which are close to the dystonin (Dst) gene locus. To investigate whether Dst is the causative gene of the novel mutant phenotype, we crossed the mutant with Dst gene trap (DstGt) mice. Compound heterozygotes showed a typical dt phenotype with sensory degeneration and progressive motor symptoms. DNA sequencing analysis identified a nonsense mutation within the spectrin repeats of the plakin domain. The novel mutant allele was named dt23Rbrc. Motor abnormalities in homozygous dt23Rbrc/dt23Rbrc mice are not as severe as homozygous DstGt/DstGt mice. Histological analyses showed abnormal neurofilament (NF) accumulation in the nervous system of homozygous dt23Rbrc/dt23Rbrc mice, which is characteristic of the dt phenotype. We mapped the distribution of abnormal NF-accumulated neurons in the brain and found that they were located specifically in the brainstem, spinal cord, and in regions such as the vestibular nucleus, reticular nucleus, and red nucleus, which are implicated in posture and motor coordination pathways. The quantification of abnormal NF accumulation in the cytoplasm and spheroids (axons) of neurons showed that abnormal NF immunoreactivity was lower in homozygous dt23Rbrc/dt23Rbrc mice than in homozygous DstGt/DstGt mice. Therefore, we have identified a novel hypomorphic allele of dt, which causes histological abnormalities in the central nervous system that may account for the abnormal motor phenotype. This novel spontaneously occurring mutant may become a good model of hereditary sensory and autonomic neuropathy type 6, which is caused by mutations in the human DST gene.


Assuntos
Distúrbios Distônicos/complicações , Distúrbios Distônicos/genética , Distonina/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Transtornos Heredodegenerativos do Sistema Nervoso/etiologia , Repetições de Microssatélites/genética , Fatores Etários , Animais , Animais Recém-Nascidos , Cromossomos Humanos Par 1/genética , Distúrbios Distônicos/patologia , Distonina/metabolismo , Potencial Evocado Motor/genética , Comportamento Exploratório/fisiologia , Genótipo , Transtornos Heredodegenerativos do Sistema Nervoso/genética , Transtornos Heredodegenerativos do Sistema Nervoso/patologia , Humanos , Filamentos Intermediários/genética , Filamentos Intermediários/metabolismo , Filamentos Intermediários/ultraestrutura , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes Neurológicos , Atividade Motora/genética , Neurônios/fisiologia , Neurônios/ultraestrutura , Reflexo de Endireitamento/genética , Percepção Espacial/fisiologia
18.
Brain Res ; 1650: 162-171, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27581393

RESUMO

Tottering mutant mice carry a mutation in the pore-forming subunit (α1A) of CaV2.1 (P/Q-type) voltage-gated calcium ion (Ca2+) channels resulting in reduced neuronal Ca2+ current density. We assessed male tottering mice for spatial learning using the Morris water maze. Tottering mice performed worse than wild type mice, suggesting abnormal hippocampal function. Because Ca2+ influx via voltage-dependent Ca2+ channels regulates neuronal survival and function, we assessed hippocampus volume and cell density using hematoxylin and eosin stained serial sections. Adult hippocampal neurogenesis was assessed using 5-bromo-2'-deoxyuridine (BrdU) labeling with fluorescent immunohistochemistry (IHC) and proliferating cell nuclear antigen (PCNA) with diaminobenzidine IHC. We double-labeled neurons using fluorescence IHC with BrdU-neuronal nuclei (Neu-N) or double labeling of astrocytes using BrdU-glial fibrillary protein, respectively, to assess cell proliferation and survival. We assessed numbers of dying cells using fluoro-Jade histochemistry. Decreased hippocampal volume, increased dentate hilar and hippocampal CA1 cell densities were observed in tottering mice compared to wild type mice. Cell proliferation was increased in the hilus and CA2 region of tottering mice compared to wild type mice. Dendritic intersections in Sholl analysis were decreased for tottering mouse CA1 pyramidal neurons compared to wild type mice. The increased regional cell density coincides with increases in cell proliferation in similar, non-neurogenic areas of the hippocampus of tottering mice. Thus, hippocampal alterations observed in adult tottering mice appear to result from changes in neuronal morphology and proliferation in non-neurogenic areas of the hippocampus, and less through altered adult hippocampal neurogenesis or cell death.


Assuntos
Canais de Cálcio Tipo N/genética , Canais de Cálcio Tipo N/metabolismo , Animais , Bromodesoxiuridina , Cálcio/metabolismo , Proliferação de Células , Sobrevivência Celular , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes Neurológicos , Neurônios/metabolismo , Aprendizagem Espacial
19.
Neurochem Int ; 99: 233-238, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27498335

RESUMO

The specific antagonistic interaction between dopamine D1 and adenosine A1 receptors (D1/A1), as well as between dopamine D2 and adenosine A2a receptors (D2/A2a) exist not only at the receptor/receptor level, but also at the level of the secondary messengers. In this study, we examined the possible changes in these interactions at the level of cAMP formation in membrane preparation from "weaver" mouse striatum (a genetic model of Parkinson disease), by using specific agonists of these receptors. We also examined in the striatum of the "weaver" mouse the interaction between D1 and D2 dopamine receptors. Our results showed that in the striatum of "weaver" mice: a) the cAMP synthesis induced by D1 receptor activation (SKF 38393), was significantly reduced compared to control mice, while A1 receptor activation (L-PIA) leaded to a more intense inhibition of the D1-induced cAMP-formation compared to the controls, b) the cAMP synthesis which was induced by A2a receptor activation (CGS 21680), was significantly increased compared to the control mice. The specific D2 receptor agonist Quinpirole, added in low concentrations, caused a significant reduction of the A2a-induced cAMP formation, which was not observed in the control mouse. Furthermore, the D1 receptor induced cAMP synthesis was significantly higher in control compared to "weaver" striatum, which was more efficiently downregulated by D2 receptor agonist Quinpirole. These results suggest that the sensitivity to D1 and A2a receptor agonists is altered and that the interaction between D1/A1 and D2/A2a receptors is enhanced in the striatum of the "weaver" mutation, while an uncoupling between D1 and D2 receptors was observed. Since the adenylate cyclase basal activity did not differ between "weaver" and control striatum, the above-mentioned changes seem to be due to alterations in the function of the adenosine/dopamine receptors and their coupling to the G-proteins.


Assuntos
Adenilil Ciclases/metabolismo , Corpo Estriado/metabolismo , Receptor A2A de Adenosina/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/metabolismo , Animais , Corpo Estriado/efeitos dos fármacos , Agonistas de Dopamina/farmacologia , Neurônios Dopaminérgicos/efeitos dos fármacos , Neurônios Dopaminérgicos/metabolismo , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Masculino , Camundongos , Camundongos Mutantes Neurológicos , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , Quimpirol/farmacologia , Receptores de Dopamina D1/agonistas , Receptores de Dopamina D2/agonistas
20.
J Neurosci Res ; 94(12): 1520-1530, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27426866

RESUMO

Krabbe's disease is a leukodystrophy resulting from deficiency of galactosylceramidase and the accumulation of galactosylsphingosine (psychosine) in the nervous system. Psychosine is believed to cause central demyelination by killing oligodendrocytes. Quantitative analysis of this process is lacking. To address this, we generated a new transgenic reporter twitcher line in which myelinating oligodendrocytes are genetically marked by the expression of LacZ under control of the myelin basic protein (MBP) promoter. MBP-LacZ-twitcher transgenic mice were used for unbiased stereological quantification of ß-galactosidase+ oligodendrocytes in the spinal cord. As expected, we found decreased numbers of these cells in mutant cords, paralleling the severity of clinical disease. The decrease of oligodendrocytes does not correlate well with the increase of psychosine. The new MBP-LacZ-twitcher line will be a useful genetic tool for measuring changes in oligodendrocyte numbers in different regions of the mutant CNS and in preclinical trials of therapies to prevent demyelination. © 2016 Wiley Periodicals, Inc.


Assuntos
Óperon Lac/genética , Leucodistrofia de Células Globoides/genética , Leucodistrofia de Células Globoides/patologia , Oligodendroglia/patologia , Envelhecimento , Animais , Células Cultivadas , Genes Reporter/genética , Camundongos , Camundongos Mutantes Neurológicos , Camundongos Transgênicos , Mutação , Proteínas da Mielina/biossíntese , Proteínas da Mielina/genética , Neuroglia/metabolismo , Psicosina/metabolismo , beta-Galactosidase/metabolismo
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