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1.
Development ; 147(11)2020 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-32439756

RESUMO

The formation and maintenance of sharp boundaries between groups of cells play a vital role during embryonic development as they serve to compartmentalize cells with similar fates. Some of these boundaries also act as organizers, with the ability to induce specific cell fates and morphogenesis in the surrounding cells. The midbrain-hindbrain boundary (MHB) is such an organizer: it acts as a lineage restriction boundary to prevent the intermingling of cells with different developmental fates. However, the mechanisms underlying the lineage restriction process remain unclear. Here, using novel fluorescent knock-in reporters, live imaging, Cre/lox-mediated lineage tracing, atomic force microscopy-based cell adhesion assays and mutant analysis, we analyze the process of lineage restriction at the MHB and provide mechanistic details. Specifically, we show that lineage restriction occurs by the end of gastrulation, and that the subsequent formation of sharp gene expression boundaries in the developing MHB occur through complementary mechanisms, i.e. cell-fate plasticity and cell sorting. Furthermore, we show that cell sorting at the MHB involves differential adhesion among midbrain and hindbrain cells that is mediated by N-cadherin and Eph-ephrin signaling.


Assuntos
Adesão Celular/fisiologia , Mesencéfalo/metabolismo , Rombencéfalo/metabolismo , Peixe-Zebra/metabolismo , Animais , Animais Geneticamente Modificados/crescimento & desenvolvimento , Animais Geneticamente Modificados/metabolismo , Sistemas CRISPR-Cas/genética , Caderinas/genética , Caderinas/metabolismo , Linhagem da Célula , Embrião não Mamífero/metabolismo , Efrinas/antagonistas & inibidores , Efrinas/genética , Efrinas/metabolismo , Gastrulação , Edição de Genes , Mesencéfalo/patologia , Microscopia de Força Atômica , Microscopia de Fluorescência , Morfolinos/metabolismo , Fatores de Transcrição Otx/genética , Fatores de Transcrição Otx/metabolismo , Rombencéfalo/patologia , Transdução de Sinais , Imagem com Lapso de Tempo , Peixe-Zebra/crescimento & desenvolvimento , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
2.
PLoS Biol ; 18(6): e3000734, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32502201

RESUMO

Cerebral cavernous malformations (CCMs) are vascular lesions predominantly developing in the central nervous system (CNS), with no effective treatments other than surgery. Loss-of-function mutation in CCM1/krev interaction trapped 1 (KRIT1), CCM2, or CCM3/programmed cell death 10 (PDCD10) causes lesions that are characterized by abnormal vascular integrity. Vascular endothelial cadherin (VE-cadherin), a major regulator of endothelial cell (EC) junctional integrity is strongly disorganized in ECs lining the CCM lesions. We report here that microRNA-27a (miR-27a), a negative regulator of VE-cadherin, is elevated in ECs isolated from mouse brains developing early CCM lesions and in cultured ECs with CCM1 or CCM2 depletion. Furthermore, we show miR-27a acts downstream of kruppel-like factor (KLF)2 and KLF4, two known key transcription factors involved in CCM lesion development. Using CD5-2 (a target site blocker [TSB]) to prevent the miR-27a/VE-cadherin mRNA interaction, we present a potential therapy to increase VE-cadherin expression and thus rescue the abnormal vascular integrity. In CCM1- or CCM2-depleted ECs, CD5-2 reduces monolayer permeability, and in Ccm1 heterozygous mice, it restores dermal vessel barrier function. In a neonatal mouse model of CCM disease, CD5-2 normalizes vasculature and reduces vascular leakage in the lesions, inhibits the development of large lesions, and significantly reduces the size of established lesions in the hindbrain. Furthermore, CD5-2 limits the accumulation of inflammatory cells in the lesion area. Our work has established that VE-cadherin is a potential therapeutic target for normalization of the vasculature and highlights that targeting miR-27a/VE-cadherin interaction by CD5-2 is a potential novel therapy for the devastating disease, CCM.


Assuntos
Antígenos CD/metabolismo , Caderinas/metabolismo , Hemangioma Cavernoso do Sistema Nervoso Central/genética , MicroRNAs/metabolismo , Animais , Regulação para Baixo/genética , Hemangioma Cavernoso do Sistema Nervoso Central/patologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/metabolismo , Masculino , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Rombencéfalo/irrigação sanguínea , Rombencéfalo/patologia , Regulação para Cima/genética , Proteína rhoA de Ligação ao GTP/metabolismo
3.
J Infect Chemother ; 29(7): 703-706, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36996936

RESUMO

Listeria monocytogenes sometimes causes central nervous system infections. However, rhombencephalitis is a rare form of L. monocytogenes infection. Its clinical symptoms and magnetic resonance imaging (MRI) findings are often similar to those of vertebrobasilar stroke. We present the case of a 79-year-old woman with Listeria rhombencephalitis presenting with rhinorrhea and productive cough. She had giant cell arteritis (GCA) treated with prednisolone and methotrexate. She was admitted for loss of appetite, rhinorrhea, and productive cough. These symptoms were alleviated without specific treatment; however, she suddenly developed multiple cranial nerve palsies, and MRI showed hyperintense signals on diffusion-weighted imaging and hypointense signals on apparent diffusion coefficient in the brainstem. Ischemic stroke due to exacerbation of GCA was suspected, and treatment with intravenous methylprednisolone was initiated; however, seizures occurred, and a lumbar puncture was performed. Cerebrospinal fluid and blood cultures revealed L. monocytogenes, and she was diagnosed with Listeria rhombencephalitis. Although antibiotic treatment was continued, the patient died. Thus, when patients with rhinorrhea or productive cough develop sudden cranial nerve palsy, Listeria rhombencephalitis should be considered as a differential diagnosis, and lumbar puncture should be performed.


Assuntos
Arterite de Células Gigantes , Listeria , Listeriose , Acidente Vascular Cerebral , Feminino , Humanos , Idoso , Listeriose/complicações , Listeriose/diagnóstico , Listeriose/tratamento farmacológico , Arterite de Células Gigantes/complicações , Arterite de Células Gigantes/diagnóstico , Arterite de Células Gigantes/patologia , Tosse , Rombencéfalo/patologia , Acidente Vascular Cerebral/patologia
4.
Am J Med Genet A ; 185(4): 1047-1058, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33381921

RESUMO

We aim to characterize patients with Gomez-López-Hernández syndrome (GLHS) clinically and to investigate them molecularly. A clinical protocol, including a morphological and neuropsychological assessment, was applied to 13 patients with GLHS. Single-nucleotide polymorphism (SNP) array and whole-exome sequencing were undertaken; magnetic resonance imaging was performed in 12 patients, including high-resolution, heavily T2-weighted sequences (HRT2) in 6 patients to analyze the trigeminal nerves. All patients presented alopecia; two did not present rhombencephalosynapsis (RES); trigeminal anesthesia was present in 5 of the 11 patients (45.4%); brachycephaly/brachyturricephaly and mid-face retrusion were found in 84.6 and 92.3% of the patients, respectively. One patient had intellectual disability. HRT2 sequences showed trigeminal nerve hypoplasia in four of the six patients; all four had clinical signs of trigeminal anesthesia. No common candidate gene was found to explain GLHS phenotype. RES does not seem to be an obligatory finding in respect of GLHS diagnosis. We propose that a diagnosis of GLHS should be considered in patients with at least two of the following criteria: focal non-scarring alopecia, rhombencephalosynapsis, craniofacial anomalies (brachyturrycephaly, brachycephaly or mid-face retrusion), trigeminal anesthesia or anatomic abnormalities of the trigeminal nerve. Studies focusing on germline whole genome sequencing or DNA and/or RNA sequencing of the alopecia tissue may be the next step for the better understanding of GLHS etiology.


Assuntos
Anormalidades Múltiplas/genética , Fosfatase Ácida/genética , Alopecia/genética , Cerebelo/anormalidades , Anormalidades Craniofaciais/genética , Sequenciamento do Exoma , Transtornos do Crescimento/genética , Síndromes Neurocutâneas/genética , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/diagnóstico por imagem , Anormalidades Múltiplas/patologia , Adolescente , Adulto , Alopecia/diagnóstico , Alopecia/diagnóstico por imagem , Alopecia/patologia , Brasil/epidemiologia , Cerebelo/diagnóstico por imagem , Cerebelo/patologia , Criança , Pré-Escolar , Anormalidades Craniofaciais/diagnóstico , Anormalidades Craniofaciais/diagnóstico por imagem , Anormalidades Craniofaciais/patologia , Feminino , Transtornos do Crescimento/diagnóstico , Transtornos do Crescimento/diagnóstico por imagem , Transtornos do Crescimento/patologia , Humanos , Lactente , Recém-Nascido , Imageamento por Ressonância Magnética , Masculino , Síndromes Neurocutâneas/diagnóstico , Síndromes Neurocutâneas/diagnóstico por imagem , Síndromes Neurocutâneas/patologia , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Rombencéfalo/diagnóstico por imagem , Rombencéfalo/patologia , Nervo Trigêmeo/diagnóstico por imagem , Nervo Trigêmeo/metabolismo , Nervo Trigêmeo/patologia , Adulto Jovem
5.
Hum Mol Genet ; 27(5): 860-874, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29325119

RESUMO

The peripheral deafness gene Mir96 is expressed in both the cochlea and central auditory circuits. To investigate whether it plays a role in the auditory system beyond the cochlea, we characterized homozygous Dmdo/Dmdo mice with a point mutation in miR-96. Anatomical analysis demonstrated a significant decrease in volume of auditory nuclei in Dmdo/Dmdo mice. This decrease resulted from decreased cell size. Non-auditory structures in the brainstem of Dmdo/Dmdo mice or auditory nuclei of the congenital deaf Cldn14-/- mice revealed no such differences. Electrophysiological analysis in the medial nucleus of the trapezoid body (MNTB) showed that principal neurons fired preferentially multiple action potentials upon depolarization, in contrast to the single firing pattern prevalent in controls and Cldn14-/- mice. Immunohistochemistry identified significantly reduced expression of two predicted targets of the mutated miR-96, Kv1.6 and BK channel proteins, possibly contributing to the electrophysiological phenotype. Microscopic analysis of the Dmdo/Dmdo calyx of Held revealed a largely absent compartmentalized morphology, as judged by SV2-labeling. Furthermore, MNTB neurons from Dmdo/Dmdo mice displayed larger synaptic short-term depression, slower AMPA-receptor decay kinetics and a larger NMDA-receptor component, reflecting a less matured stage. Again, these synaptic differences were not present between controls and Cldn14-/- mice. Thus, deafness genes differentially affect the auditory brainstem. Furthermore, our study identifies miR-96 as an essential gene regulatory network element of the auditory system which is required for functional maturation in the peripheral and central auditory system alike.


Assuntos
MicroRNAs/fisiologia , Rombencéfalo/crescimento & desenvolvimento , Rombencéfalo/patologia , Animais , Tamanho Celular , Claudinas/genética , Núcleo Coclear/crescimento & desenvolvimento , Núcleo Coclear/patologia , Regulação da Expressão Gênica no Desenvolvimento , Subunidades alfa do Canal de Potássio Ativado por Cálcio de Condutância Alta/genética , Camundongos Knockout , Camundongos Mutantes , Mutação , Plasticidade Neuronal , Neurônios/patologia , Superfamília Shaker de Canais de Potássio/genética , Sinapses/patologia , Transmissão Sináptica
6.
J Neurovirol ; 26(6): 976-979, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32839947

RESUMO

Listeria rhombencephalitis (L. rhombencephalitis) is an uncommon form of central nervous system infection caused by Listeria monocytogenes (LM). It often occurs to immunocompetent individuals. Here, we described the case of a 45-year-old female patient without medical histories, who presented for high-grade fever, headache, and focal neurological manifestations. She was initially empirically diagnosed with acute disseminated encephalomyelitis (ADEM) because of clinical symptoms, acute clinical course, and neuroimaging. However, the biochemical analysis of cerebral spinal fluid (CSF) questioned the diagnosis of ADEM. The final diagnosis of L. rhombencephalitis was based on CSF culture for LM. Thus, L. rhombencephalitis should be preferentially and empirically considered for a patient with significantly elevated lactic acid and moderately increased red cells in CSF at early time, accompanied with rapidly progressive neurological dysfunctions involved in the brain stem.


Assuntos
Encefalite/diagnóstico , Encefalomielite Aguda Disseminada/diagnóstico , Febre/diagnóstico , Cefaleia/diagnóstico , Ácido Láctico/líquido cefalorraquidiano , Listeria monocytogenes/patogenicidade , Biomarcadores/líquido cefalorraquidiano , Diagnóstico Diferencial , Encefalite/líquido cefalorraquidiano , Encefalite/patologia , Encefalomielite Aguda Disseminada/líquido cefalorraquidiano , Encefalomielite Aguda Disseminada/patologia , Feminino , Febre/líquido cefalorraquidiano , Febre/patologia , Cefaleia/líquido cefalorraquidiano , Cefaleia/patologia , Humanos , Listeria monocytogenes/isolamento & purificação , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Rombencéfalo/diagnóstico por imagem , Rombencéfalo/metabolismo , Rombencéfalo/patologia
7.
Am J Med Genet A ; 182(4): 623-627, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32003537

RESUMO

Rhombencephalosynapsis (RES) is a rare congenital anomaly of the hindbrain characterized by fusion of the cerebellar hemispheres, cerebellar peduncles, and dentate nuclei with vermian absence or hypogenesis. This anomaly can be isolated or part of a larger spectrum of cerebral abnormalities. At least 90 cases are described in the literature and it has been associated with VACTERL and Gomez-Lopez-Hernandez syndrome (GLHS). The most common congenital syndrome associated with RES is GLHS, a rare presumed genetic disorder with over 30 cases thus far described in the literature. No genetic cause has been identified for RES or GLHS. We report two probands diagnosed with GLHS based on clinical criteria. Each proband had RES and bi-parietal scalp alopecia as well as neurologic findings and phenotypic features including trigeminal anesthesia, borderline hypertelorism, midface retrusion, and motor delay. Oliginucleotide-SNP microarray on the male proband revealed a 1.05 Mb copy duplication of uncertain clinical significance at 15q21.3 while oligonucleotide-SNP microarray for the female proband did not reveal any abnormalities. Exome sequencing (ES) was performed on both patients and did not identify any variants that could explain the GLHS phenotype. To our knowledge, these are the first two patients with GLHS described in the literature to undergo ES. Both patients had mild neurologic manifestations requiring physical therapy in early life without known diagnostic cause. Patients found to have scalp alopecia or trigeminal anesthesia with gross motor delay should be evaluated for RES or GLHS as well as screened for associated syndromes and have a complete neurodevelopmental evaluation.


Assuntos
Anormalidades Múltiplas/patologia , Alopecia/patologia , Cerebelo/anormalidades , Anormalidades Craniofaciais/patologia , Exoma/genética , Transtornos do Crescimento/patologia , Síndromes Neurocutâneas/patologia , Rombencéfalo/patologia , Anormalidades Múltiplas/genética , Adolescente , Alopecia/genética , Cerebelo/patologia , Anormalidades Craniofaciais/genética , Feminino , Transtornos do Crescimento/genética , Humanos , Masculino , Síndromes Neurocutâneas/genética , Fenótipo , Rombencéfalo/anormalidades , Sequenciamento do Exoma
8.
Am J Med Genet A ; 182(7): 1761-1766, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32302043

RESUMO

Gomez-López-Hernández syndrome (GLHS) is characterized by rhombencephalosynapsis (RES), alopecia, trigeminal anesthesia and a distinctive phenotype, including brachyturricephaly. It has been suggested that GLHS should be considered as part of the spectrum of RES-associated conditions that include alopecia, trigeminal anesthesia, and craniofacial anomalies, rather than a distinct entity. To the best of our knowledge, 57 patients with GLHS have been described. Despite its first description in 1979, the etiology of this syndrome remains unknown. Here, we describe, to our knowledge, the first case of a patient with GLHS who was molecularly evaluated and had been prenatally exposed to misoprostol. We also reviewed the clinical and morphological features of the patients described to date to better delineate the phenotype and focus on any evidence for adverse pregnancy outcomes or exposure, including teratogens.


Assuntos
Anormalidades Múltiplas/tratamento farmacológico , Anormalidades Múltiplas/genética , Alopecia/genética , Cerebelo/anormalidades , Anormalidades Craniofaciais/tratamento farmacológico , Anormalidades Craniofaciais/genética , Transtornos do Crescimento/tratamento farmacológico , Transtornos do Crescimento/genética , Misoprostol/uso terapêutico , Síndromes Neurocutâneas/tratamento farmacológico , Síndromes Neurocutâneas/genética , Anormalidades Múltiplas/diagnóstico por imagem , Anormalidades Múltiplas/patologia , Alopecia/diagnóstico por imagem , Alopecia/tratamento farmacológico , Alopecia/patologia , Cerebelo/diagnóstico por imagem , Cerebelo/patologia , Criança , Pré-Escolar , Anormalidades Craniofaciais/diagnóstico por imagem , Anormalidades Craniofaciais/patologia , Feminino , Transtornos do Crescimento/diagnóstico por imagem , Transtornos do Crescimento/patologia , Humanos , Imageamento por Ressonância Magnética , Síndromes Neurocutâneas/diagnóstico por imagem , Síndromes Neurocutâneas/patologia , Fenótipo , Rombencéfalo/diagnóstico por imagem , Rombencéfalo/patologia , Nervo Trigêmeo/diagnóstico por imagem , Nervo Trigêmeo/efeitos dos fármacos , Nervo Trigêmeo/patologia
9.
Nature ; 506(7489): 445-50, 2014 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-24553142

RESUMO

Ependymomas are common childhood brain tumours that occur throughout the nervous system, but are most common in the paediatric hindbrain. Current standard therapy comprises surgery and radiation, but not cytotoxic chemotherapy as it does not further increase survival. Whole-genome and whole-exome sequencing of 47 hindbrain ependymomas reveals an extremely low mutation rate, and zero significant recurrent somatic single nucleotide variants. Although devoid of recurrent single nucleotide variants and focal copy number aberrations, poor-prognosis hindbrain ependymomas exhibit a CpG island methylator phenotype. Transcriptional silencing driven by CpG methylation converges exclusively on targets of the Polycomb repressive complex 2 which represses expression of differentiation genes through trimethylation of H3K27. CpG island methylator phenotype-positive hindbrain ependymomas are responsive to clinical drugs that target either DNA or H3K27 methylation both in vitro and in vivo. We conclude that epigenetic modifiers are the first rational therapeutic candidates for this deadly malignancy, which is epigenetically deregulated but genetically bland.


Assuntos
Ilhas de CpG/genética , Ependimoma/genética , Epigênese Genética/genética , Animais , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Metilação de DNA/efeitos dos fármacos , Células-Tronco Embrionárias/metabolismo , Ependimoma/tratamento farmacológico , Epigenômica , Feminino , Regulação Neoplásica da Expressão Gênica , Inativação Gênica/efeitos dos fármacos , Histonas/efeitos dos fármacos , Histonas/metabolismo , Humanos , Lactente , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Mutação/genética , Fenótipo , Complexo Repressor Polycomb 2/metabolismo , Prognóstico , Rombencéfalo/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Proc Natl Acad Sci U S A ; 114(51): E11029-E11036, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29203673

RESUMO

Misfolding of tau proteins into prions and their propagation along neural circuits are thought to result in neurodegeneration causing Alzheimer's disease, progressive supranuclear palsy, chronic traumatic encephalopathy, and other tauopathies. Little is known about the molecular processes mediating tau prion replication and spreading in different brain regions. Using transgenic (Tg) mice with a neuronal promoter driving expression of human mutant (P301S) tau, we found that tau prion formation and histopathologic deposition is largely restricted to the hindbrain. Unexpectedly, tau mRNA and protein levels did not differ between the forebrain and hindbrain, suggesting that other factors modulating the conversion of tau into a prion exist and are region specific. Using a cell-based prion propagation assay, we discovered that tau prion replication is suppressed by forebrain-derived inhibitors, one of which is sortilin, a lysosomal sorting receptor. We also show that sortilin expression is higher in the forebrain than the hindbrain across the life span of the Tg mice, suggesting that sortilin, at least in part, inhibits forebrain tau prion replication in vivo. Our findings provide evidence for selective vulnerability in mice resulting in highly regulated levels of tau prion propagation, thus affording a model for identification of additional molecules that could mitigate the levels of tau prions in human tauopathies.


Assuntos
Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Agregação Patológica de Proteínas/genética , Agregação Patológica de Proteínas/metabolismo , Proteínas tau/genética , Proteínas tau/metabolismo , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Modelos Animais de Doenças , Expressão Gênica , Humanos , Camundongos , Camundongos Transgênicos , Neurônios/metabolismo , Fosforilação , Ligação Proteica , Rombencéfalo/metabolismo , Rombencéfalo/patologia
11.
PLoS Genet ; 13(4): e1006746, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28453519

RESUMO

Mid-hindbrain malformations can occur during embryogenesis through a disturbance of transient and localized gene expression patterns within these distinct brain structures. Rho guanine nucleotide exchange factor (ARHGEF) family members are key for controlling the spatiotemporal activation of Rho GTPase, to modulate cytoskeleton dynamics, cell division, and cell migration. We identified, by means of whole exome sequencing, a homozygous frameshift mutation in the ARHGEF2 as a cause of intellectual disability, a midbrain-hindbrain malformation, and mild microcephaly in a consanguineous pedigree of Kurdish-Turkish descent. We show that loss of ARHGEF2 perturbs progenitor cell differentiation and that this is associated with a shift of mitotic spindle plane orientation, putatively favoring more symmetric divisions. The ARHGEF2 mutation leads to reduction in the activation of the RhoA/ROCK/MLC pathway crucial for cell migration. We demonstrate that the human brain malformation is recapitulated in Arhgef2 mutant mice and identify an aberrant migration of distinct components of the precerebellar system as a pathomechanism underlying the midbrain-hindbrain phenotype. Our results highlight the crucial function of ARHGEF2 in human brain development and identify a mutation in ARHGEF2 as novel cause of a neurodevelopmental disorder.


Assuntos
Movimento Celular/genética , Mutação da Fase de Leitura/genética , Deficiência Intelectual/genética , Fatores de Troca de Nucleotídeo Guanina Rho/genética , Animais , Citoesqueleto/genética , Exoma/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Homozigoto , Humanos , Deficiência Intelectual/diagnóstico por imagem , Deficiência Intelectual/patologia , Imageamento por Ressonância Magnética , Masculino , Mesencéfalo/diagnóstico por imagem , Mesencéfalo/patologia , Camundongos , Linhagem , Rombencéfalo/diagnóstico por imagem , Rombencéfalo/patologia , Transdução de Sinais , Proteína rhoA de Ligação ao GTP/genética
12.
Glia ; 67(4): 619-633, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30585358

RESUMO

Astrocytes support normal brain function, but may also contribute to neurodegeneration when they become reactive under pathological conditions such as stroke. However, the molecular underpinnings of this context-dependent interplay between beneficial and detrimental properties in reactive astrogliosis have remained incompletely understood. Therefore, using the RiboTag technique, we immunopurified translating mRNAs specifically from astrocytes 72 hr after transient middle cerebral artery occlusion in mice (tMCAO), thereby generating a stroke-specific astroglial translatome database. We found that compared to control brains, reactive astrocytes after tMCAO show an enrichment of transcripts linked to the A2 phenotype, which has been associated with neuroprotection. However, we found that astrocytes also upregulate a large number of potentially neurotoxic genes. In total, we identified the differential expression of 1,003 genes and 38 transcription factors, of which Stat3, Sp1, and Spi1 were the most prominent. To further explore the effects of Stat3-mediated pathways on stroke pathogenesis, we subjected mice with an astrocyte-specific conditional deletion of Stat3 to tMCAO, and found that these mice have reduced stroke volume and improved motor outcome 72 hr after focal ischemia. Taken together, our study extends the emerging database of novel astrocyte-specific targets for stroke therapy, and supports the role of astrocytes as critical safeguards of brain function in health and disease.


Assuntos
Astrócitos/metabolismo , Perfilação da Expressão Gênica/métodos , Infarto da Artéria Cerebral Média/patologia , Rombencéfalo/patologia , Animais , Biologia Computacional , Conexina 43/genética , Conexina 43/metabolismo , Modelos Animais de Doenças , Feminino , Galectina 3/genética , Galectina 3/metabolismo , Regulação da Expressão Gênica/genética , Imunoprecipitação , Infarto da Artéria Cerebral Média/fisiopatologia , Lipocalina-2/genética , Lipocalina-2/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas do Tecido Nervoso/metabolismo , Teste de Desempenho do Rota-Rod , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo
13.
Am J Med Genet C Semin Med Genet ; 178(4): 432-439, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30580482

RESUMO

Rhombencephalosynapsis (RES) is a unique cerebellar malformation characterized by fusion of the cerebellar hemispheres with partial or complete absence of a recognizable cerebellar vermis. Subsets of patients also have other brain malformations such as midbrain fusion with aqueductal stenosis, characteristic craniofacial features (prominent forehead, flat midface, hypertelorism, ear abnormalities), and somatic malformations (heart, kidney, spine, and limb defects). Similar to known genetic brain malformations, the RES cerebellar malformation is highly stereotyped, yet no genetic causes have been identified. Here, we outline our current understanding of the genetic basis for RES, discuss limitations, and outline future approaches to identifying the causes of this fascinating brain malformation.


Assuntos
Doenças Cerebelares/diagnóstico , Doenças Cerebelares/genética , Cerebelo/anormalidades , Transtornos do Crescimento/diagnóstico , Rombencéfalo/anormalidades , Transtornos do Crescimento/genética , Humanos , Rombencéfalo/patologia
14.
Am J Med Genet C Semin Med Genet ; 178(4): 382-386, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30580485

RESUMO

Due to the efforts of the clinical and scientific communities and boosted by recent advances in genetic technologies, we now understand the molecular mechanisms underlying most of the frequent and recognizable human malformation syndromes. However, some well-established human malformation syndromes remain without a molecular diagnosis despite intensive investigation. This issue of Seminars mines the phenotypic entries in OMIM and estimates that of the documented 2,034 unsolved entries likely to represent a rare genetic disease, only 160 are well-established and possibly amenable to investigation. This issue also reviews well-characterized and extensively investigated human malformation syndromes and associations that remain unsolved, including the following: Dubowitz syndrome (MIM 223370%), Hallermann-Streiff syndrome (MIM 234100%), PHACE syndrome (MIM 606519), Oculocerebrocutaneous syndrome (MIM 164180), Aicardi syndrome (MIM 304050%), Gomez-Lopez-Hernandez syndrome and Rhombencephalosynapsis (MIM 601853%), VACTERL (MIM 192350%), and Nablus syndrome (MIM #608156). Possible explanations for their intractability to molecular diagnosis are explored, including genetic and phenotypic heterogeneity, mosaicism, epigenetics, gene-environment interactions, and other non-Mendelian contributions. Finally, this issue of Seminars presents a path forward for these unsolved rare conditions and suggests a renewed focus on solving amendable OMIM disorders. It is clear that the way forward will require new technologies, global cooperation, and data sharing; these will also be necessary to help reach the vision of the International Rare Diseases Research Consortium (IRDiRC), that is to enable all people living with a rare disease to receive an accurate diagnosis, care and available therapy within 1 year of coming to medical attention.


Assuntos
Anormalidades Múltiplas/patologia , Alopecia/patologia , Doenças Cerebelares/patologia , Cerebelo/anormalidades , Anormalidades Craniofaciais/patologia , Eczema/patologia , Transtornos do Crescimento/patologia , Deficiência Intelectual/patologia , Microcefalia/patologia , Síndromes Neurocutâneas/patologia , Doenças Raras/patologia , Cerebelo/patologia , Fácies , Humanos , Rombencéfalo/patologia , Síndrome
15.
Eur J Neurosci ; 48(4): 2050-2070, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30019432

RESUMO

Functional recovery from central nervous system injury is likely to be partly due to a rearrangement of neural circuits. In this context, the corticobulbar (corticoreticular) motor projections onto different nuclei of the ponto-medullary reticular formation (PMRF) were investigated in 13 adult macaque monkeys after either, primary motor cortex injury (MCI) in the hand area, or spinal cord injury (SCI) or Parkinson's disease-like lesions of the nigro-striatal dopaminergic system (PD). A subgroup of animals in both MCI and SCI groups was treated with neurite growth promoting anti-Nogo-A antibodies, whereas all PD animals were treated with autologous neural cell ecosystems (ANCE). The anterograde tracer BDA was injected either in the premotor cortex (PM) or in the primary motor cortex (M1) to label and quantify corticobulbar axonal boutons terminaux and en passant in PMRF. As compared to intact animals, after MCI the density of corticobulbar projections from PM was strongly reduced but maintained their laterality dominance (ipsilateral), both in the presence or absence of anti-Nogo-A antibody treatment. In contrast, the density of corticobulbar projections from M1 was increased following opposite hemi-section of the cervical cord (at C7 level) and anti-Nogo-A antibody treatment, with maintenance of contralateral laterality bias. In PD monkeys, the density of corticobulbar projections from PM was strongly reduced, as well as that from M1, but to a lesser extent. In conclusion, the densities of corticobulbar projections from PM or M1 were affected in a variable manner, depending on the type of lesion/pathology and the treatment aimed to enhance functional recovery.


Assuntos
Lesões Encefálicas/patologia , Córtex Motor/lesões , Córtex Motor/patologia , Doença de Parkinson/patologia , Tratos Piramidais/patologia , Formação Reticular/patologia , Rombencéfalo/patologia , Traumatismos da Medula Espinal/patologia , Animais , Anticorpos Bloqueadores/administração & dosagem , Lesões Encefálicas/terapia , Transplante de Células , Modelos Animais de Doenças , Feminino , Mãos/patologia , Macaca fascicularis , Masculino , Técnicas de Rastreamento Neuroanatômico , Proteínas Nogo/imunologia , Doença de Parkinson/terapia , Traumatismos da Medula Espinal/terapia , Transplante Autólogo
16.
Clin Anat ; 31(3): 314-322, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29344999

RESUMO

In 1891, Hans Chiari described a group of congenital hindbrain anomalies, which were eventually named after him. He classified these malformations into three types (Chiari malformations I, II, and III), and four years later added the Chiari IV malformation. However, numerous reports across the literature do not seem to fit Chiari's original descriptions of these malformations, so researchers have been encouraged to propose new classifications to encompass these variants (e.g., Chiari 0, Chiari1.5, and Chiari 3.5 malformations). Moreover, there is a continued misunderstanding and misuse of the term "Chiari IV malformation." Therefore, the current review intended to describe anatomical, pathophysiological, and clinical aspects of the newer classifications with clarifications of the Chiari malformations. We reviewed available literature about Chiari malformations and their variants using "PubMed" and "Google Scholar." We also looked into the term Chiari IV, clarifying its original description and citing examples where the term has been used erroneously. References in the reviewed articles were searched manually. Variants of the originally described Chiari malformations are termed Chiari 0, Chiari 1.5, and Chiari 3.5. Each has distinct anatomical characteristics and some of these are extremely rare and incompatible with life (e.g. Chiari 3.5). Chiari IV malformation has been further clarified. Some physicians might be unfamiliar with the newer classifications of Chiari malformations because these conditions are rare or even unique. Furthermore, care is needed in using the term "Chiari IV malformation", which must be consistent with Chiari's original description, i.e. an occipital encephalocele containing supratentorial contents. Clin. Anat. 31:314-322, 2018. © 2018 Wiley Periodicals, Inc.


Assuntos
Malformação de Arnold-Chiari/classificação , Malformação de Arnold-Chiari/diagnóstico por imagem , Malformação de Arnold-Chiari/patologia , Humanos , Imageamento por Ressonância Magnética , Rombencéfalo/patologia
17.
Clin Anat ; 31(2): 202-215, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28612426

RESUMO

Although the Chiari malformations are well-studied and described developmental anomalies, there remains some incongruity in regards to their underlying etiologies. A number of theories have been proposed with the purpose of accounting for the embryology and pathogenesis of the Chiari I and II malformations and their associated complications and clinical syndromes. The present review aims to review the pertinent literature for all of the main theories that have been proposed, and outline their validity and relevance to our contemporary understanding of these anomalies. Clin. Anat. 31:202-215, 2018. © 2017 Wiley Periodicals, Inc.


Assuntos
Malformação de Arnold-Chiari/embriologia , Malformação de Arnold-Chiari/diagnóstico por imagem , Medula Cervical/patologia , Humanos , Imageamento por Ressonância Magnética , Rombencéfalo/patologia
18.
Development ; 141(3): 556-62, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24401374

RESUMO

Neuropilin 1 (NRP1) is a receptor for class 3 semaphorins and vascular endothelial growth factor (VEGF) A and is essential for cardiovascular development. Biochemical evidence supports a model for NRP1 function in which VEGF binding induces complex formation between NRP1 and VEGFR2 to enhance endothelial VEGF signalling. However, the relevance of VEGF binding to NRP1 for angiogenesis in vivo has not yet been examined. We therefore generated knock-in mice expressing Nrp1 with a mutation of tyrosine (Y) 297 in the VEGF binding pocket of the NRP1 b1 domain, as this residue was previously shown to be important for high affinity VEGF binding and NRP1-VEGFR2 complex formation. Unexpectedly, this targeting strategy also severely reduced NRP1 expression and therefore generated a NRP1 hypomorph. Despite the loss of VEGF binding and attenuated NRP1 expression, homozygous Nrp1(Y297A/Y297A) mice were born at normal Mendelian ratios, arguing against NRP1 functioning exclusively as a VEGF164 receptor in embryonic angiogenesis. By overcoming the mid-gestation lethality of full Nrp1-null mice, homozygous Nrp1(Y297A/Y297A) mice revealed essential roles for NRP1 in postnatal angiogenesis and arteriogenesis in the heart and retina, pathological neovascularisation of the retina and angiogenesis-dependent tumour growth.


Assuntos
Neovascularização Patológica/metabolismo , Neovascularização Fisiológica , Neuropilina-1/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Animais Recém-Nascidos , Sequência de Bases , Peso Corporal/genética , Carcinogênese/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Dados de Sequência Molecular , Miocárdio/metabolismo , Miocárdio/patologia , Neovascularização Patológica/embriologia , Neovascularização Patológica/genética , Neovascularização Fisiológica/genética , Neuropilina-1/metabolismo , Oxigênio , Ligação Proteica , Artéria Retiniana/patologia , Rombencéfalo/embriologia , Rombencéfalo/metabolismo , Rombencéfalo/patologia , Análise de Sobrevida
19.
J Biol Regul Homeost Agents ; 31(4): 991-996, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29254304

RESUMO

The aim of this study was to analyze the changes in coagulation in meningioma patients treated with different injections using the method of acute hypervolemic hemodilution (AHH). One hundred fifty hindbrain membrane meningioma patients were randomly divided into 5 groups, 30 per group. The first group were injected 40ml/time with Danhong after anesthesia induction; the second group were injected with 40ml~60ml/time Kangai and combined with interventional chemotherapy and embolization procedure; the third group of AHH were injected with polygeline 15ml/kg; the fourth group were injected with hydroxyethyl starch (130/0.4) sodium chloride in doses of 15ml/kg; the control group underwent basic treatment for lowering blood pressure and lowering blood fat. The changes of coagulation index were recorded before and after surgery and before and after the injection of different medications. Compared to the control group, for the first group of AHH, after being treated for 10 days and 30 days, the concentrations of bone specific alkaline phosphatase (BALP), bone Gla protein (BGP) and pro-collagen carboxy-terminal propeptide (PICP) were higher than that of the control group, the levels of endotoxin (ET) and C-reactive protein (CRP) were decreased compared to the control group (p less than 0.05); for the second group of AHH, after being treated for 10 days, the index of prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen (Fg) were not significantly changed, but the related level of vascular endothelial growth factor (VEGF) significantly decreased (p less than 0.05). Comparing the coagulation function index after surgery in the third and fourth groups, there were no significant changes in mean arterial pressure (MAP) level, heart rate (HR) value presented a low decrease, central venous pressure (CVP) level increased and the level of interleukin IL-6 showed a steady state after increasing. Analyzing the levels of interleukin IL-8 and tumor necrosis factor-α (TNF-α) after surgery, it was seen that in the third group they increased and in the fourth group they decreased (p less than 0.05). Danhong injection improved the coagulation function and microcirculation of patients, Kangai injection and interventional chemotherapy and embolization restrained the appearance of tumor angiogenesis, AHH operation with polygeline injection and hydroxyethyl starch (130/0.4) sodium chloride kept blood flow in normal parameters.


Assuntos
Coagulação Sanguínea/efeitos dos fármacos , Cardiotônicos/uso terapêutico , Medicamentos de Ervas Chinesas/uso terapêutico , Hemodiluição/métodos , Neoplasias Meníngeas/tratamento farmacológico , Meningioma/tratamento farmacológico , Adulto , Fosfatase Alcalina/genética , Fosfatase Alcalina/metabolismo , Pressão Arterial/efeitos dos fármacos , Pressão Arterial/fisiologia , Biomarcadores/metabolismo , Viscosidade Sanguínea/efeitos dos fármacos , Proteína C-Reativa/genética , Proteína C-Reativa/metabolismo , Embolização Terapêutica/métodos , Endotoxinas/metabolismo , Feminino , Fibrinogênio/genética , Fibrinogênio/metabolismo , Expressão Gênica , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Humanos , Derivados de Hidroxietil Amido/administração & dosagem , Masculino , Neoplasias Meníngeas/sangue , Neoplasias Meníngeas/patologia , Neoplasias Meníngeas/cirurgia , Meningioma/sangue , Meningioma/patologia , Meningioma/cirurgia , Pessoa de Meia-Idade , Osteocalcina/genética , Osteocalcina/metabolismo , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Substitutos do Plasma/administração & dosagem , Poligelina/administração & dosagem , Pró-Colágeno/genética , Pró-Colágeno/metabolismo , Rombencéfalo/efeitos dos fármacos , Rombencéfalo/metabolismo , Rombencéfalo/patologia , Rombencéfalo/cirurgia , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
20.
Neurol Neurochir Pol ; 51(2): 180-183, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28110853

RESUMO

We describe a case of 52-year-old woman with a medical history of Crohn's disease presented abrupt fever, asymmetrical multiple cranial nerve palsies and focal neurological symptoms localized to the brainstem. The patient was initially diagnosed with ischaemic stroke, because of acute clinical course and results of neuroimaging. Cerebrospinal fluid analysis revealed mild infection with negative Gram staining and culture. Final diagnosis of Listeria monocytogenes brainstem infection (rhombencephalitis) was set up on the basis of further clinical course and positive blood cultures. Listerial rhombencephalitis should be kept in mind in immunocompromised adult patients who develop fever, asymmetrical multiple cranial nerve palsies and focal neurological symptoms localized to the brainstem even without typical neuroimaging, cerebrospinal fluid findings and negative cultures. Early diagnosis and adequate antibiotic treatment is of crucial importance.


Assuntos
Meningite por Listeria/diagnóstico , Rombencéfalo , Doença de Crohn/complicações , Diagnóstico Diferencial , Imagem de Difusão por Ressonância Magnética , Evolução Fatal , Feminino , Humanos , Pessoa de Meia-Idade , Infecções Oportunistas/diagnóstico , Rombencéfalo/patologia , Tomografia Computadorizada por Raios X
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