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1.
Int J Mol Sci ; 22(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201282

RESUMO

Aging is associated with a general decline of cognitive functions, and it is widely accepted that this decline results from changes in the expression of proteins involved in regulation of synaptic plasticity. However, several lines of evidence have accumulated that suggest that the impaired function of the aged brain may be related to significant alterations in the energy metabolism. In the current study, we employed the label-free "Total protein approach" (TPA) method to focus on the similarities and differences in energy metabolism proteomes of young (1-month-old) and aged (22-month-old) murine brains. We quantified over 7000 proteins in each of the following three analyzed brain structures: the hippocampus, the cerebral cortex and the cerebellum. To the best of our knowledge, this is the most extensive quantitative proteomic description of energy metabolism pathways during the physiological aging of mice. The analysis demonstrates that aging does not significantly affect the abundance of total proteins in the studied brain structures, however, the levels of proteins constituting energy metabolism pathways differ significantly between young and aged mice.


Assuntos
Envelhecimento/metabolismo , Cerebelo/metabolismo , Córtex Cerebral/metabolismo , Metabolismo Energético , Hipocampo/metabolismo , Proteoma/metabolismo , Envelhecimento/patologia , Animais , Cerebelo/patologia , Córtex Cerebral/patologia , Feminino , Hipocampo/patologia , Camundongos , Camundongos Endogâmicos C57BL , Proteoma/análise
2.
J Biol Chem ; 297(1): 100853, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34090874

RESUMO

The highly conserved dual-specificity tyrosine phosphorylation-regulated kinase 1A (Dyrk1A) plays crucial roles during central nervous system development and homeostasis. Furthermore, its hyperactivity is considered responsible for some neurological defects in individuals with Down syndrome. We set out to establish a zebrafish model expressing human Dyrk1A that could be further used to characterize the interaction between Dyrk1A and neurological phenotypes. First, we revealed the prominent expression of dyrk1a homologs in cerebellar neurons in the zebrafish larval and adult brains. Overexpression of human dyrk1a in postmitotic cerebellar Purkinje neurons resulted in a structural misorganization of the Purkinje cells in cerebellar hemispheres and a compaction of this cell population. This impaired Purkinje cell organization was progressive, leading to an age-dependent dispersal of Purkinje neurons throughout the cerebellar molecular layer with larval swim deficits resulting in miscoordination of swimming and reduced exploratory behavior in aged adults. We also found that the structural misorganization of the larval Purkinje cell layer could be rescued by pharmacological treatment with Dyrk1A inhibitors. We further reveal the in vivo efficiency of a novel selective Dyrk1A inhibitor, KuFal194. These findings demonstrate that the zebrafish is a well-suited vertebrate organism to genetically model severe neurological diseases with single cell type specificity. Such models can be used to relate molecular malfunction to cellular deficits, impaired tissue formation, and organismal behavior and can also be used for pharmacological compound testing and validation.


Assuntos
Cerebelo/metabolismo , Síndrome de Down/genética , Neurônios/metabolismo , Proteínas Quinases/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Tirosina Quinases/genética , Proteínas de Peixe-Zebra/genética , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Cerebelo/patologia , Modelos Animais de Doenças , Síndrome de Down/patologia , Humanos , Neurônios/patologia , Fosforilação/genética , Células de Purkinje/metabolismo , Células de Purkinje/patologia , Peixe-Zebra/genética
3.
Molecules ; 26(9)2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-34066579

RESUMO

Mass spectrometry imaging is a powerful tool for analyzing the different kinds of molecules in tissue sections, but some substances cannot be measured easily, due to their physicochemical properties. In such cases, chemical derivatization could be applied to introduce the charge into the molecule and facilitate its detection. Here, we study cholesterol derivatization with betaine aldehyde from tissue slices and evaluate how different sample preparation methods influence the signal from the derivatization product. In this study, we have tested different solutions for betaine aldehyde, different approaches to betaine aldehyde deposition (number of layers, deposition nozzle height), and different MALDI matrices for its analysis. As a result, we proved that the proposed approach could be used for the analysis of cholesterol in different tissues.


Assuntos
Betaína/análogos & derivados , Colesterol/análise , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Betaína/química , Encéfalo/metabolismo , Cerebelo/metabolismo , Colesterol/química , Íons , Rim/metabolismo , Limite de Detecção , Fígado/metabolismo , Camundongos
4.
Molecules ; 26(10)2021 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-34069330

RESUMO

Angiotensin (Ang) II is well-known to have potent pro-oxidant and pro-inflammatory effects in the brain. Extensive crosstalk between the primary Ang II receptor, Ang type 1 receptor (AT1R), and the cannabinoid type 1 receptor (CB1R) has been demonstrated by various groups in the last decade. Since activation of glial CB1R has been demonstrated to play a key role in the resolution of inflammatory states, we investigated the role of Ang II (100 nM) and/or ACEA (10 nM), a potent CB1R-specific agonist in the regulation of inflammatory markers in astrocytes from spontaneously hypertensive rats (SHR) and Wistar rats. Astrocytes were cultured from brainstems and cerebellums of SHR and Wistar rats and assayed for IL1ß and IL10 gene expression and secreted fraction, in treated and non-treated cells, by employing qPCR and ELISA, respectively. mRNA expression of both IL10 and IL1ß were significantly elevated in untreated brainstem and cerebellar astrocytes isolated from SHR when compared to Wistar astrocytes. No changes were observed in the secreted fraction. While ACEA-treatment resulted in a significant increase in IL10 gene expression in Wistar brainstem astrocytes (Log2FC ≥ 1, p < 0.05), its effect in SHR brainstem astrocytes was diminished. Ang II treatment resulted in a strong inhibitory effect on IL10 gene expression in astrocytes from both brain regions of SHR and Wistar rats (Log2FC ≤ -1, p < 0.05), and an increase in IL1ß gene expression in brainstem astrocytes from both strains (Log2FC ≥ 1, p < 0.05). Co-treatment of Ang II and ACEA resulted in neutralization of Ang II-mediated effect in Wistar brainstem and cerebellar astrocytes, but not SHR astrocytes. Neither Ang II nor ACEA resulted in any significant changes in IL10 or IL1ß secreted proteins. These data suggest that Ang II and ACEA have opposing roles in the regulation of inflammatory gene signature in astrocytes isolated from SHR and Wistar rats. This however does not translate into changes in their secreted fractions.


Assuntos
Angiotensina II/farmacologia , Ácidos Araquidônicos/farmacologia , Expressão Gênica/efeitos dos fármacos , Interleucina-10/genética , Interleucina-18/genética , Animais , Astrócitos/efeitos dos fármacos , Cerebelo/citologia , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Masculino , RNA Mensageiro/genética , Ratos , Ratos Endogâmicos SHR , Ratos Wistar
5.
Wiad Lek ; 74(6): 1409-1413, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34159929

RESUMO

OBJECTIVE: The aim: To define the degree for glial acidic fibrillary protein expression on the structural components of cerebellum of the rats in health and when rats influenced by the food additives complex. PATIENTS AND METHODS: Materials and methods: In order to determine the degree of expression of the immunohistochemical marker GFAP on the structural components of the cerebellum of rats we applied immunohistochemical, morphometric and statistical methods in our study. RESULTS: Results: In histological specimens at the end of 1st week of observation in the gray matter of the cerebellum there occurred a gradual increase in 1.16 times of the average number of GFAP-positive cells. At the end of 4th week of the experimental study, the average number of GFAP-positive cells increased accurately (at p<0.05 compared to the control group) in 1.27 times, at the end of 8th week it has increased in 1.99 times, at the end of 12th week in 2.25, and at the end of 16th week in 2.39 times. CONCLUSION: Conclusions: The outcomes of our study are as follows the increase in the average number of GFAP-positive cells is directly related to the decrease in the average number of major neurons of the gray matter of the brain, while the fluctuations in the average number of astrocytic glia cells represent a compensatory mechanism in the recovery of gray matter neurons of the brain from neural stem cells with the subsequent development of reactive astrogliosis and, thereafter the possible development of neuropathology.


Assuntos
Aditivos Alimentares , Neuroglia , Astrócitos/metabolismo , Cerebelo/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Neuroglia/metabolismo
6.
Biomolecules ; 11(6)2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-34074021

RESUMO

Epipregnanolone (3ß-hydroxy-5ß-pregnan-20-one, Epi) is an endogenous steroid with important physiological effects and high affinity for GABAA receptors. The effect of Epi on GABA-induced chloride current (IGABA) in native neurons has hardly been studied. In this work, we studied the influence of Epi on the IGABA in the Purkinje cells of rat cerebellum and pyramidal neurons of rat hippocampus with the patch clamp technique. We showed that Epi is a positive modulator of the IGABA with EC50 of 5.7 µM in Purkinje cells and 9.3 µM in hippocampal neurons. Epi-induced potentiation of the IGABA was more potent at low vs. high GABA concentrations. Isopregnanolone (3ß-hydroxy-5α-pregnan-20-one, Iso) counteracted Epi, reducing its potentiating effect by 2-2.3 times. Flumazenil, a nonsteroidal GABAA receptor antagonist, does not affect the Epi-induced potentiation. Comparison of the potentiating effects of Epi and allopregnanolone (3α-hydroxy-5α-pregnan-20-one, ALLO) showed that ALLO is, at least, a four times more potent positive modulator than Epi. The combined application of ALLO and Epi showed that the effects of these two steroids are not additive. We conclude that Epi has a dual effect on the IGABA increasing the current in the control solution and decreasing the stimulatory effect of ALLO.


Assuntos
Cerebelo/metabolismo , Agonistas de Receptores de GABA-A/farmacologia , Hipocampo/metabolismo , Pregnanolona/farmacologia , Células Piramidais/metabolismo , Receptores de GABA-A/metabolismo , Animais , Ratos , Ratos Wistar
7.
PLoS Biol ; 19(6): e3001297, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34111112

RESUMO

Recent studies have shown that long noncoding RNAs (lncRNAs) are critical regulators in the central nervous system (CNS). However, their roles in the cerebellum are currently unclear. In this work, we identified the isoform 204 of lncRNA Gm2694 (designated as lncRNA-Promoting Methylation (lncRNA-PM)) is highly expressed in the cerebellum and derived from the antisense strand of the upstream region of Cerebellin-1 (Cbln1), a well-known critical cerebellar synaptic organizer. LncRNA-PM exhibits similar spatiotemporal expression pattern as Cbln1 in the postnatal mouse cerebellum and activates the transcription of Cbln1 through Pax6/Mll1-mediated H3K4me3. In mouse cerebellum, lncRNA-PM, Pax6/Mll1, and H3K4me3 are all associated with the regulatory regions of Cbln1. Knockdown of lncRNA-PM in cerebellum causes deficiencies in Cbln1 expression, cerebellar synaptic integrity, and motor function. Together, our work reveals an lncRNA-mediated transcriptional activation of Cbln1 through Pax6-Mll1-H3K4me3 and provides novel insights of the essential roles of lncRNA in the cerebellum.


Assuntos
Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Proteína de Leucina Linfoide-Mieloide/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Fator de Transcrição PAX6/metabolismo , Precursores de Proteínas/metabolismo , RNA Longo não Codificante/metabolismo , Sinapses/metabolismo , Processamento Alternativo/genética , Cerebelo/metabolismo , Regulação da Expressão Gênica , Células HEK293 , Histona-Lisina N-Metiltransferase/genética , Humanos , Atividade Motora , Proteína de Leucina Linfoide-Mieloide/genética , Neurônios/metabolismo , Terminações Pré-Sinápticas/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Longo não Codificante/genética , Ativação Transcricional/genética
8.
Elife ; 102021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34096502

RESUMO

Traditionally, research unraveling seasonal neuroplasticity in songbirds has focused on the male song control system and testosterone. We longitudinally monitored the song behavior and neuroplasticity in male and female starlings during multiple photoperiods using Diffusion Tensor and Fixel-Based techniques. These exploratory data-driven whole-brain methods resulted in a population-based tractogram confirming microstructural sexual dimorphisms in the song control system. Furthermore, male brains showed hemispheric asymmetries in the pallium, whereas females had higher interhemispheric connectivity, which could not be attributed to brain size differences. Only females with large brains sing but differ from males in their song behavior by showing involvement of the hippocampus. Both sexes experienced multisensory neuroplasticity in the song control, auditory and visual system, and cerebellum, mainly during the photosensitive period. This period with low gonadal hormone levels might represent a 'sensitive window' during which different sensory and motor systems in the cerebrum and cerebellum can be seasonally re-shaped in both sexes.


Assuntos
Cerebelo/fisiologia , Cérebro/fisiologia , Plasticidade Neuronal , Estorninhos/fisiologia , Vocalização Animal , Animais , Percepção Auditiva , Cerebelo/diagnóstico por imagem , Cerebelo/metabolismo , Cérebro/diagnóstico por imagem , Cérebro/metabolismo , Imagem de Tensor de Difusão , Estradiol/sangue , Feminino , Masculino , Atividade Motora , Fotoperíodo , Estações do Ano , Caracteres Sexuais , Estorninhos/sangue , Testosterona/sangue , Percepção Visual
9.
PLoS Genet ; 17(6): e1009608, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34161333

RESUMO

The X-linked GRIA3 gene encodes the GLUA3 subunit of AMPA-type glutamate receptors. Pathogenic variants in this gene were previously reported in neurodevelopmental diseases, mostly in male patients but rarely in females. Here we report a de novo pathogenic missense variant in GRIA3 (c.1979G>C; p. R660T) identified in a 1-year-old female patient with severe epilepsy and global developmental delay. When exogenously expressed in human embryonic kidney (HEK) cells, GLUA3_R660T showed slower desensitization and deactivation kinetics compared to wildtype (wt) GLUA3 receptors. Substantial non-desensitized currents were observed with the mutant but not for wt GLUA3 with prolonged exposure to glutamate. When co-expressed with GLUA2, the decay kinetics were similarly slowed in GLUA2/A3_R660T with non-desensitized steady state currents. In cultured cerebellar granule neurons, miniature excitatory postsynaptic currents (mEPSCs) were significantly slower in R660T transfected cells than those expressing wt GLUA3. When overexpressed in hippocampal CA1 neurons by in utero electroporation, the evoked EPSCs and mEPSCs were slower in neurons expressing R660T mutant compared to those expressing wt GLUA3. Therefore our study provides functional evidence that a gain of function (GoF) variant in GRIA3 may cause epileptic encephalopathy and global developmental delay in a female subject by enhancing synaptic transmission.


Assuntos
Proteínas do Ovo/genética , Mutação com Ganho de Função , Proteínas de Membrana/genética , Neurônios/metabolismo , Receptores de AMPA/genética , Espasmos Infantis/genética , Sequência de Aminoácidos , Animais , Cerebelo/metabolismo , Cerebelo/patologia , Pré-Escolar , Proteínas do Ovo/metabolismo , Feminino , Expressão Gênica , Células HEK293 , Hipocampo/metabolismo , Hipocampo/patologia , Humanos , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos ICR , Modelos Moleculares , Neurônios/patologia , Cultura Primária de Células , Conformação Proteica , Receptores de AMPA/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Espasmos Infantis/metabolismo , Espasmos Infantis/patologia
10.
Int J Mol Sci ; 22(9)2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-34068557

RESUMO

Depression is a prominent complex psychiatric disorder, usually complicated through expression of comorbid conditions, with chronic pain being among the most prevalent. This comorbidity is consistently associated with a poor prognosis and has been shown to negatively impact patient outcomes. With a global rise in this condition presenting itself, the importance of discovering long-term, effective, and affordable treatments is crucial. Electroacupuncture has demonstrated renowned success in its use for the treatment of pain and is a widely recognized therapy in clinical practice for the treatment of various psychosomatic disorders, most notably depression. Our study aimed to investigate the effects and mechanisms of Acid-Saline (AS) inducing states of chronic pain and depression comorbidity in the cerebellum, using the ST36 acupoint as the therapeutic intervention. Furthermore, the role of TRPV1 was relatedly explored through the use of TRPV1-/- mice (KO). The results indicated significant differences in the four behavioral tests used to characterize pain and depression states in mice. The AS and AS + SHAM group showed significant differences when compared to the Control and AS + EA groups in the von Frey and Hargreaves's tests, as well as the Open-Field and Forced Swimming tests. This evidence was further substantiated in the protein levels observed in immunoblotting, with significant differences between the AS and AS + SHAM groups when compared to the AS + EA and AS + KO groups being identified. In addition, immunofluorescence visibly served to corroborate the quantitative outcomes. Conclusively these findings suggest that AS-induced chronic pain and depression comorbidity elicits changes in the cerebellum lobules VI, VII, VIII, which are ameliorated through the use of EA at ST36 via its action on TRPV1 and related molecular pathways. The action of TRPV1 is not singular in CPDC, which would suggest other potential targets such as acid-sensing ion channel subtype 3 (ASIC3) or voltage-gated sodium channels (Navs) that could be explored in future studies.


Assuntos
Canais Iônicos Sensíveis a Ácido/genética , Dor Crônica/genética , Depressão/genética , Canais de Cátion TRPV/genética , Ácidos/toxicidade , Pontos de Acupuntura , Animais , Cerebelo/metabolismo , Cerebelo/patologia , Cerebelo/efeitos da radiação , Dor Crônica/induzido quimicamente , Dor Crônica/complicações , Dor Crônica/terapia , Comorbidade , Depressão/complicações , Depressão/patologia , Modelos Animais de Doenças , Eletroacupuntura , Humanos , Camundongos , Camundongos Knockout , Solução Salina/toxicidade , Natação
11.
Ann Neurol ; 90(1): 101-117, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33949707

RESUMO

OBJECTIVE: The objective of this study was to report the identification of antibodies against the glutamate kainate receptor subunit 2 (GluK2-abs) in patients with autoimmune encephalitis, and describe the clinical-immunological features and antibody effects. METHODS: Two sera from 8 patients with similar rat brain immunostaining were used to precipitate the antigen from neuronal cultures. A cell-based assay (CBA) with GluK2-expressing HEK293 cells was used to assess 596 patients with different neurological disorders, and 23 healthy controls. GluK2-ab effects were determined by confocal microscopy in cultured neurons and electrophysiology in GluK2-expressing HEK293 cells. RESULTS: Patients' antibodies precipitated GluK2. GluK2 antibody-specificity was confirmed by CBA, immunoprecipitation, GluK2-immunoabsorption, and GluK2 knockout brain immunohistochemistry. In 2 of 8 samples, antibodies reacted with additional GluK2 epitopes present in GluK1 or GluK3; in both, the reactivity was abrogated after GluK2 immuno-absorption. Six of 8 patients developed acute encephalitis and clinical or magnetic resonance imaging (MRI) features of predominant cerebellar involvement (4 presenting as cerebellitis, which in 2 patients caused obstructive hydrocephalus), and 2 patients had other syndromes (1 with cerebellar symptoms). One of the samples showed mild reactivity with non-kainate receptors (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors [AMPAR] and N-methyl-D-aspartate receptors [NMDAR]) leading to identify 6 additional cases with GluK2-abs among patients with anti-AMPAR (5/71) or anti-NMDAR encephalitis (1/73). GluK2-abs internalized GluK2 in HEK293 cells and neurons; these antibody-effects were reversible in neurons. A significant reduction of GluK2-mediated currents was observed in cells treated with patients' GluK2 serum following the time frame of antibody-mediated GluK2 internalization. INTERPRETATION: GluK2-abs associate with an encephalitis with prominent clinicoradiological cerebellar involvement. The antibody effects are predominantly mediated by internalization of GluK2. ANN NEUROL 2021;90:107-123.


Assuntos
Autoanticorpos/sangue , Encefalite/imunologia , Receptores de Ácido Caínico/imunologia , Animais , Cerebelo/metabolismo , Encefalite/sangue , Encefalite/metabolismo , Células HEK293 , Humanos , Neurônios/metabolismo , Ratos , Receptores de Ácido Caínico/metabolismo
12.
Neuroscience ; 467: 91-109, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-34033869

RESUMO

Hevin is a matricellular glycoprotein that plays important roles in neural developmental processes such as neuronal migration, synaptogenesis and synaptic plasticity. In contrast to other matricellular proteins whose expression decreases when development is complete, hevin remains highly expressed, suggesting its involvement in adult brain function. In vitro studies have shown that hevin can have different post-translational modifications. However, the glycosylation pattern of hevin in the human brain remains unknown, as well as its relative distribution and localization. The present study provides the first thorough characterization of hevin protein expression by Western blot in postmortem adult human brain. Our results demonstrated two major specific immunoreactive bands for hevin: an intense band migrating around 130 kDa, and a band migrating around 100 kDa. Biochemical assays revealed that both hevin bands have a different glycosylation pattern. Subcellular fractionation showed greater expression in membrane-enriched fraction than in cytosolic preparation, and a higher expression in prefrontal cortex (PFC) compared to hippocampus (HIP), caudate nucleus (CAU) and cerebellum (CB). We confirmed that a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS4) and matrixmetalloproteinase 3 (MMP-3) proteases digestion led to an intense double band with similar molecular weight to that described as SPARC-like fragment (SLF). Finally, hevin immunoreactivity was also detected in human astrocytoma, meningioma, cerebrospinal fluid and serum samples, but was absent from any blood cell type.


Assuntos
Proteínas da Matriz Extracelular , Osteonectina , Adulto , Western Blotting , Encéfalo/metabolismo , Proteínas de Ligação ao Cálcio , Cerebelo/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Humanos , Neurogênese , Osteonectina/metabolismo
13.
J Neurol ; 268(11): 4163-4169, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33988764

RESUMO

BACKGROUND: AP3B2 is one of the subunits of vesicle coat protein AP3 and is specifically expressed in central nervous system neurons. AP3B2 antibody has been reported in patients with autoimmune cerebellar ataxia and various extracerebellar symptoms. However, there have been few reports on its clinical features and treatment response. METHODS: We report a 47-year-old man with AP3B2 antibody who presented with insidious-onset paresthesia and gait disturbance. His serum and cerebrospinal fluid (CSF) showed reactivity with the cytoplasm of Purkinje cells and granular layer synapses comparable to the reported specific pattern of anti-AP3B2 IgG, and this was confirmed by a cell-based assay. His symptoms improved after the administration of intravenous immunoglobulin, and oral prednisone and mycophenolate mofetil. Extensive examination and long-term follow-up showed no evidence of malignancy. A literature review was included to emphasize the neurological syndrome associated with this rare autoantibody. RESULTS: Eleven cases with AP3B2 antibody, including our patient, were identified. The diversity of symptoms, including cerebellar and sensory ataxia, paresthesia, and weakness, was in line with the extensive binding of AP3B2 antibody to the spinal cord gray matter, dorsal root ganglia, cerebellar cortex, and nucleus. In the CSF, half of patients had elevated white blood cell counts, increased protein concentrations, or CSF-specific oligoclonal bands. All previous cases had subacute onsets and no improvement was noted after immunotherapy. CONCLUSION: Our case indicated that disorders associated with AP3B2 antibody can also start insidiously. Immunotherapy is warranted given the possibility of clinical improvement.


Assuntos
Ataxia Cerebelar , Doenças da Medula Espinal , Complexo 3 de Proteínas Adaptadoras , Subunidades beta do Complexo de Proteínas Adaptadoras , Autoanticorpos/metabolismo , Sistema Nervoso Central/metabolismo , Cerebelo/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade
14.
PLoS Genet ; 17(5): e1009506, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33956822

RESUMO

Identifying the molecular underpinnings of the neural specializations that underlie human cognitive and behavioral traits has long been of considerable interest. Much research on human-specific changes in gene expression and epigenetic marks has focused on the prefrontal cortex, a brain structure distinguished by its role in executive functions. The cerebellum shows expansion in great apes and is gaining increasing attention for its role in motor skills and cognitive processing, including language. However, relatively few molecular studies of the cerebellum in a comparative evolutionary context have been conducted. Here, we identify human-specific methylation in the lateral cerebellum relative to the dorsolateral prefrontal cortex, in a comparative study with chimpanzees (Pan troglodytes) and rhesus macaques (Macaca mulatta). Specifically, we profiled genome-wide methylation levels in the three species for each of the two brain structures and identified human-specific differentially methylated genomic regions unique to each structure. We further identified which differentially methylated regions (DMRs) overlap likely regulatory elements and determined whether associated genes show corresponding species differences in gene expression. We found greater human-specific methylation in the cerebellum than the dorsolateral prefrontal cortex, with differentially methylated regions overlapping genes involved in several conditions or processes relevant to human neurobiology, including synaptic plasticity, lipid metabolism, neuroinflammation and neurodegeneration, and neurodevelopment, including developmental disorders. Moreover, our results show some overlap with those of previous studies focused on the neocortex, indicating that such results may be common to multiple brain structures. These findings further our understanding of the cerebellum in human brain evolution.


Assuntos
Cerebelo/metabolismo , Metilação de DNA , Epigênese Genética , Proteínas ADAM , Animais , Autoantígenos , Proteínas de Transporte , Chade , Ilhas de CpG , Feminino , Regulação da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Macaca mulatta/genética , Masculino , Proteínas dos Microfilamentos , Proteínas do Tecido Nervoso , Pan troglodytes/genética , Fosfoinositídeo Fosfolipase C , Proteínas Serina-Treonina Quinases , Proteínas , Proteínas Associadas SAP90-PSD95 , Especificidade da Espécie , Sítio de Iniciação de Transcrição
15.
J Alzheimers Dis ; 81(2): 769-785, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33814431

RESUMO

BACKGROUND: Transmissible spongiform encephalopathies (TSEs) are rare neurodegenerative disorders that affect animals and humans. Bovine spongiform encephalopathy (BSE) in cattle, and Creutzfeld-Jakob Disease (CJD) in humans belong to this group. The causative agent of TSEs is called "prion", which corresponds to a pathological form (PrPSc) of a normal cellular protein (PrPC) expressed in nerve cells. PrPSc is resistant to degradation and can induce abnormal folding of PrPC, and TSEs are characterized by extensive spongiosis and gliosis and the presence of PrPSc amyloid plaques. CJD presents initially with clinical symptoms similar to Alzheimer's disease (AD). In AD, tau aggregates and amyloid-ß protein plaques are associated with memory loss and cognitive impairment in patients. OBJECTIVE: In this work, we study the role of tau and its relationship with PrPSc plaques in CJD. METHODS: Multiple immunostainings with specific antibodies were carried out and analyzed by confocal microscopy. RESULTS: We found increased expression of the glial fibrillary acidic protein (GFAP) and matrix metalloproteinase (MMP-9), and an exacerbated apoptosis in the granular layer in cases with prion disease. In these cases, tau protein phosphorylated at Thr-231 was overexpressed in the axons and dendrites of Purkinje cells and the extensions of parallel fibers in the cerebellum. CONCLUSION: We conclude that phosphorylation of tau may be a response to a toxic and inflammatory environment generated by the pathological form of prion.


Assuntos
Cerebelo/metabolismo , Síndrome de Creutzfeldt-Jakob/patologia , Doenças Priônicas/patologia , Proteínas tau/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Encefalopatias/metabolismo , Encefalopatias/patologia , Bovinos , Cerebelo/patologia , Síndrome de Creutzfeldt-Jakob/metabolismo , Encefalopatia Espongiforme Bovina/metabolismo , Encefalopatia Espongiforme Bovina/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Priônicas/metabolismo , Treonina/metabolismo
16.
eNeuro ; 8(3)2021.
Artigo em Inglês | MEDLINE | ID: mdl-33863781

RESUMO

Adenosine acts as a neuromodulator and metabolic regulator of the brain through receptor dependent and independent mechanisms. In the brain, adenosine is tightly controlled through its metabolic enzyme adenosine kinase (ADK), which exists in a cytoplasmic (ADK-S) and nuclear (ADK-L) isoform. We recently discovered that ADK-L contributes to adult hippocampal neurogenesis regulation. Although the cerebellum (CB) is a highly plastic brain area with a delayed developmental trajectory, little is known about the role of ADK. Here, we investigated the developmental profile of ADK expression in C57BL/6 mice CB and assessed its role in developmental and proliferative processes. We found high levels of ADK-L during cerebellar development, which was maintained into adulthood. This pattern contrasts with that of the cerebrum, in which ADK-L expression is gradually downregulated postnatally and largely restricted to astrocytes in adulthood. Supporting a functional role in cell proliferation, we found that the ADK inhibitor 5-iodotubericine (5-ITU) reduced DNA synthesis of granular neuron precursors in a concentration-dependent manner in vitro In the developing CB, immunohistochemical studies indicated ADK-L is expressed in immature Purkinje cells and granular neuron precursors, whereas in adulthood, ADK is absent from Purkinje cells, but widely expressed in mature granule neurons and their molecular layer (ML) processes. Furthermore, ADK-L is expressed in developing and mature Bergmann glia in the Purkinje cell layer, and in astrocytes in major cerebellar cortical layers. Together, our data demonstrate an association between neuronal ADK expression and developmental processes of the CB, which supports a functional role of ADK-L in the plasticity of the CB.


Assuntos
Adenosina Quinase , Cerebelo , Adenosina Quinase/genética , Adenosina Quinase/metabolismo , Animais , Astrócitos/metabolismo , Cerebelo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo
17.
Neurology ; 96(23): e2874-e2884, 2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-33910940

RESUMO

OBJECTIVES: To test for cerebellar involvement in motor and nonmotor impairments in Parkinson disease (PD) and to determine patterns of metabolic correlations with supratentorial brain structures, we correlated clinical motor, cognitive, and psychiatric scales with cerebellar metabolism. METHODS: We included 90 patients with PD. Motor, cognitive, and psychiatric domains were assessed, and resting-state 18FDG-PET metabolic imaging was performed. The motor, cognitive, and psychiatric scores were entered separately into a principal component analysis. We looked for correlations between these 3 principal components and cerebellar metabolism. Furthermore, we extracted the mean glucose metabolism value for each significant cerebellar cluster and looked for patterns of cerebrum-cerebellum metabolic correlations. RESULTS: Severity of impairment was correlated with increased metabolism in the anterior lobes and vermis (motor domain); the right crus I, crus II, and declive (cognitive domain); and the right crus I and crus II (psychiatric domain). No results survived multiple testing corrections regarding the psychiatric domain. Moreover, we found distributed and overlapping, but not identical, patterns of metabolic correlations for motor and cognitive domains. Specific supratentorial structures (cortical structures, basal ganglia, and thalamus) were strongly correlated with each of the cerebellar clusters. CONCLUSIONS: These results confirm the role of the cerebellum in nonmotor domains of PD, with differential but overlapping patterns of metabolic correlations suggesting the involvement of cerebello-thalamo-striatal-cortical loops.


Assuntos
Sintomas Comportamentais , Cerebelo , Disfunção Cognitiva , Rede Nervosa , Doença de Parkinson , Adulto , Idoso , Gânglios da Base/diagnóstico por imagem , Gânglios da Base/metabolismo , Gânglios da Base/fisiopatologia , Sintomas Comportamentais/diagnóstico por imagem , Sintomas Comportamentais/etiologia , Sintomas Comportamentais/metabolismo , Sintomas Comportamentais/fisiopatologia , Cerebelo/diagnóstico por imagem , Cerebelo/metabolismo , Cerebelo/fisiopatologia , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/metabolismo , Córtex Cerebral/fisiopatologia , Disfunção Cognitiva/diagnóstico por imagem , Disfunção Cognitiva/etiologia , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/fisiopatologia , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Pessoa de Meia-Idade , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/metabolismo , Rede Nervosa/fisiopatologia , Doença de Parkinson/complicações , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/metabolismo , Doença de Parkinson/fisiopatologia , Tomografia por Emissão de Pósitrons , Análise de Componente Principal , Tálamo/diagnóstico por imagem , Tálamo/metabolismo , Tálamo/fisiopatologia
18.
Brain ; 144(4): 1082-1088, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33889947

RESUMO

To examine the length of a hexanucleotide expansion in C9orf72, which represents the most frequent genetic cause of frontotemporal lobar degeneration and motor neuron disease, we employed a targeted amplification-free long-read sequencing technology: No-Amp sequencing. In our cross-sectional study, we assessed cerebellar tissue from 28 well-characterized C9orf72 expansion carriers. We obtained 3507 on-target circular consensus sequencing reads, of which 814 bridged the C9orf72 repeat expansion (23%). Importantly, we observed a significant correlation between expansion sizes obtained using No-Amp sequencing and Southern blotting (P = 5.0 × 10-4). Interestingly, we also detected a significant survival advantage for individuals with smaller expansions (P = 0.004). Additionally, we uncovered that smaller expansions were significantly associated with higher levels of C9orf72 transcripts containing intron 1b (P = 0.003), poly(GP) proteins (P = 1.3 × 10- 5), and poly(GA) proteins (P = 0.005). Thorough examination of the composition of the expansion revealed that its GC content was extremely high (median: 100%) and that it was mainly composed of GGGGCC repeats (median: 96%), suggesting that expanded C9orf72 repeats are quite pure. Taken together, our findings demonstrate that No-Amp sequencing is a powerful tool that enables the discovery of relevant clinicopathological associations, highlighting the important role played by the cerebellar size of the expanded repeat in C9orf72-linked diseases.


Assuntos
Proteína C9orf72/genética , Doenças Neurodegenerativas/genética , Análise de Sequência de DNA/métodos , Idoso , Cerebelo/metabolismo , Estudos Transversais , Expansão das Repetições de DNA/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
19.
Sci Rep ; 11(1): 7312, 2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33790315

RESUMO

The neuronal membrane-associated periodic spectrin skeleton (MPS) contributes to neuronal development, remodeling, and organization. Post-translational modifications impinge on spectrin, the major component of the MPS, but their role remains poorly understood. One modification targeting spectrin is cleavage by calpains, a family of calcium-activated proteases. Spectrin cleavage is regulated by activated calpain, but also by the calcium-dependent binding of calmodulin (CaM) to spectrin. The physiologic significance of this balance between calpain activation and substrate-level regulation of spectrin cleavage is unknown. We report a strain of C57BL/6J mice harboring a single αII spectrin point mutation (Sptan1 c.3293G > A:p.R1098Q) with reduced CaM affinity and intrinsically enhanced sensitivity to calpain proteolysis. Homozygotes are embryonic lethal. Newborn heterozygotes of either gender appear normal, but soon develop a progressive ataxia characterized biochemically by accelerated calpain-mediated spectrin cleavage and morphologically by disruption of axonal and dendritic integrity and global neurodegeneration. Molecular modeling predicts unconstrained exposure of the mutant spectrin's calpain-cleavage site. These results reveal the critical importance of substrate-level regulation of spectrin cleavage for the maintenance of neuronal integrity. Given that excessive activation of calpain proteases is a common feature of neurodegenerative disease and traumatic encephalopathy, we propose that damage to the spectrin MPS may contribute to the neuropathology of many disorders.


Assuntos
Ataxia Cerebelar/genética , Espectrina/genética , Animais , Calpaína/metabolismo , Cerebelo/metabolismo , Cerebelo/patologia , Camundongos , Camundongos Endogâmicos C57BL , Mutação Puntual , Ligação Proteica , Proteólise , Espectrina/química , Espectrina/metabolismo
20.
Int J Mol Sci ; 22(9)2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33919387

RESUMO

The EBI2 receptor regulates the immune system and is expressed in various immune cells including B and T lymphocytes. It is also expressed in astrocytes in the central nervous system (CNS) where it regulates pro-inflammatory cytokine release, cell migration and protects from chemically induced demyelination. Its signaling and expression are implicated in various diseases including multiple sclerosis, where its expression is increased in infiltrating immune cells in the white matter lesions. Here, for the first time, the EBI2 protein in the CNS cells in the human brain was examined. The function of the receptor in MO3.13 oligodendrocytes, as well as its role in remyelination in organotypic cerebellar slices, were investigated. Human brain sections were co-stained for EBI2 receptor and various markers of CNS-specific cells and the human oligodendrocyte cell line MO3.13 was used to investigate changes in EBI2 expression and cellular migration. Organotypic cerebellar slices prepared from wild-type and cholesterol 25-hydroxylase knock-out mice were used to study remyelination following lysophosphatidylcholine (LPC)-induced demyelination. The data showed that EBI2 receptor is present in OPCs but not in myelinating oligodendrocytes in the human brain and that EBI2 expression is temporarily upregulated in maturing MO3.13 oligodendrocytes. Moreover, we show that migration of MO3.13 cells is directly regulated by EBI2 and that its signaling is necessary for remyelination in cerebellar slices post-LPC-induced demyelination. The work reported here provides new information on the expression and role of EBI2 in oligodendrocytes and myelination and provides new tools for modulation of oligodendrocyte biology and therapeutic approaches for demyelinating diseases.


Assuntos
Encéfalo/citologia , Cerebelo/citologia , Oligodendroglia/citologia , Receptores Acoplados a Proteínas G/metabolismo , Células-Tronco/citologia , Animais , Encéfalo/metabolismo , Cerebelo/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oligodendroglia/metabolismo , Receptores Acoplados a Proteínas G/genética , Remielinização , Células-Tronco/metabolismo
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