Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Filtros adicionais











País/Região como assunto
Intervalo de ano
1.
Am J Hum Genet ; 104(5): 925-935, 2019 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-30982609

RESUMO

Colony stimulating factor 1 receptor (CSF1R) plays key roles in regulating development and function of the monocyte/macrophage lineage, including microglia and osteoclasts. Mono-allelic mutations of CSF1R are known to cause hereditary diffuse leukoencephalopathy with spheroids (HDLS), an adult-onset progressive neurodegenerative disorder. Here, we report seven affected individuals from three unrelated families who had bi-allelic CSF1R mutations. In addition to early-onset HDLS-like neurological disorders, they had brain malformations and skeletal dysplasia compatible to dysosteosclerosis (DOS) or Pyle disease. We identified five CSF1R mutations that were homozygous or compound heterozygous in these affected individuals. Two of them were deep intronic mutations resulting in abnormal inclusion of intron sequences in the mRNA. Compared with Csf1r-null mice, the skeletal and neural phenotypes of the affected individuals appeared milder and variable, suggesting that at least one of the mutations in each affected individual is hypomorphic. Our results characterized a unique human skeletal phenotype caused by CSF1R deficiency and implied that bi-allelic CSF1R mutations cause a spectrum of neurological and skeletal disorders, probably depending on the residual CSF1R function.

2.
Mol Genet Metab ; 125(4): 351-358, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30219631

RESUMO

While pulmonary hypertension (PH) is a potentially life threatening complication of many inflammatory conditions, an association between Aicardi Goutières syndrome (AGS), a rare genetic cause of interferon (IFN) overproduction, and the development of PH has not been characterized to date. We analyzed the cardiac function of individuals with AGS enrolled in the Myelin Disorders Bioregistry Project using retrospective chart review (n = 61). Additional prospective echocardiograms were obtained when possible (n = 22). An IFN signature score, a marker of systemic inflammation, was calculated through the measurement of mRNA transcripts of type I IFN-inducible genes (interferon signaling genes or ISG). Pathologic analysis was performed as available from autopsy samples. Within our cohort, four individuals were identified to be affected by PH: three with pathogenic gain-of-function mutations in the IFIH1 gene and one with heterozygous TREX1 mutations. All studied individuals with AGS were noted to have elevated IFN signature scores (Mann-Whitney p < .001), with the highest levels in individuals with IFIH1 mutations (Mann-Whitney p < .0001). We present clinical and histologic evidence of PH in a series of four individuals with AGS, a rare interferonopathy. Importantly, IFIH1 and TREX1 may represent a novel cause of PH. Furthermore, these findings underscore the importance of screening all individuals with AGS for PH.

3.
Brain Pathol ; 28(3): 399-407, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29740948

RESUMO

Aicardi-Goutières syndrome (AGS) is an early-onset, autoimmune and genetically heterogeneous disorder with severe neurologic injury. Molecular studies have established that autosomal recessive mutations in one of the following genes are causative: TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR1 and IFIH1/MDA5. The phenotypic presentation and pathophysiology of AGS is associated with over-production of the cytokine Interferon-alpha (IFN-α) and its downstream signaling, characterized as type I interferonopathy. Astrocytes are one of the major source of IFN in the central nervous system (CNS) and it is proposed that they could be key players in AGS pathology. Astrocytes are the most ubiquitous glial cell in the CNS and perform a number of crucial and complex functions ranging from formation of blood-brain barrier, maintaining ionic homeostasis, metabolic support to synapse formation and elimination in healthy CNS. Involvement of astrocytic dysfunction in neurological diseases-Alexander's disease, Epilepsy, Alzheimer's and amyotrophic lateral sclerosis (ALS)-has been well-established. It is now known that compromised astrocytic function can contribute to CNS abnormalities and severe neurodegeneration, nevertheless, its contribution in AGS is unclear. The current review discusses known molecular and cellular pathways for AGS mutations and how it stimulates IFN-α signaling. We shed light on how astrocytes might be key players in the phenotypic presentations of AGS and emphasize the cell-autonomous and non-cell-autonomous role of astrocytes. Understanding the contribution of astrocytes will help reveal mechanisms underlying interferonopathy and develop targeted astrocyte specific therapeutic treatments in AGS.

4.
Hum Mol Genet ; 26(22): 4506-4518, 2017 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-28973395

RESUMO

Hypomyelinating leukodystrophies are heritable disorders defined by lack of development of brain myelin, but the cellular mechanisms of hypomyelination are often poorly understood. Mutations in TUBB4A, encoding the tubulin isoform tubulin beta class IVA (Tubb4a), result in the symptom complex of hypomyelination with atrophy of basal ganglia and cerebellum (H-ABC). Additionally, TUBB4A mutations are known to result in a broad phenotypic spectrum, ranging from primary dystonia (DYT4), isolated hypomyelination with spastic quadriplegia, and an infantile onset encephalopathy, suggesting multiple cell types may be involved. We present a study of the cellular effects of TUBB4A mutations responsible for H-ABC (p.Asp249Asn), DYT4 (p.Arg2Gly), a severe combined phenotype with hypomyelination and encephalopathy (p.Asn414Lys), as well as milder phenotypes causing isolated hypomyelination (p.Val255Ile and p.Arg282Pro). We used a combination of histopathological, biochemical and cellular approaches to determine how these different mutations may have variable cellular effects in neurons and/or oligodendrocytes. Our results demonstrate that specific mutations lead to either purely neuronal, combined neuronal and oligodendrocytic or purely oligodendrocytic defects that closely match their respective clinical phenotypes. Thus, the DYT4 mutation that leads to phenotypes attributable to neuronal dysfunction results in altered neuronal morphology, but with unchanged tubulin quantity and polymerization, with normal oligodendrocyte morphology and myelin gene expression. Conversely, mutations associated with isolated hypomyelination (p.Val255Ile and p.Arg282Pro) and the severe combined phenotype (p.Asn414Lys) resulted in normal neuronal morphology but were associated with altered oligodendrocyte morphology, myelin gene expression, and microtubule dysfunction. The H-ABC mutation (p.Asp249Asn) that exhibits a combined neuronal and myelin phenotype had overlapping cellular defects involving both neuronal and oligodendrocyte cell types in vitro. Only mutations causing hypomyelination phenotypes showed altered microtubule dynamics and acted through a dominant toxic gain of function mechanism. The DYT4 mutation had no impact on microtubule dynamics suggesting a distinct mechanism of action. In summary, the different clinical phenotypes associated with TUBB4A reflect the selective and specific cellular effects of the causative mutations. Cellular specificity of disease pathogenesis is relevant to developing targeted treatments for this disabling condition.


Assuntos
Neurônios/patologia , Oligodendroglia/patologia , Tubulina (Proteína)/genética , Adolescente , Adulto , Atrofia/patologia , Gânglios da Base/patologia , Encéfalo/metabolismo , Encéfalo/patologia , Catarata/congênito , Catarata/genética , Catarata/metabolismo , Catarata/patologia , Cerebelo/patologia , Criança , Pré-Escolar , Feminino , Células HeLa , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/genética , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/metabolismo , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/patologia , Humanos , Leucodistrofia Metacromática/genética , Leucodistrofia Metacromática/metabolismo , Leucodistrofia Metacromática/patologia , Imagem por Ressonância Magnética , Masculino , Microtúbulos/patologia , Pessoa de Meia-Idade , Mutação , Bainha de Mielina/genética , Bainha de Mielina/metabolismo , Fenótipo , Tubulina (Proteína)/metabolismo , Adulto Jovem
5.
Mol Genet Metab ; 122(3): 134-139, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28739201

RESUMO

BACKGROUND: Aicardi Goutières Syndrome (AGS) is a heritable interferonopathy associated with systemic autoinflammation causing interferon (IFN) elevation, central nervous system calcifications, leukodystrophy and severe neurologic sequelae. An infant with TREX1 mutations was recently found to have abnormal C26:0 lysophosphatidylcholine (C26:0 Lyso-PC) in a newborn screening platform for X-linked adrenoleukodystrophy, prompting analysis of this analyte in retrospectively collected samples from individuals affected by AGS. METHODS: In this study, we explored C26:0 Lyso-PC levels and IFN signatures in newborn blood spots and post-natal blood samples in 19 children with a molecular and clinical diagnosis of AGS and in the blood spots of 22 healthy newborns. We used Nanostring nCounter™ for IFN-induced gene analysis and a high-performance liquid chromatography with tandem mass spectrometry (HPLC MS/MS) newborn screening platform for C26:0 Lyso-PC analysis. RESULTS: Newborn screening cards from patients across six AGS associated genes were collected, with a median disease presentation of 2months. Thirteen out of 19 (68%) children with AGS had elevations of first tier C26:0 Lyso-PC (>0.4µM), that would have resulted in a second screen being performed in a two tier screening system for X-linked adrenoleukodystrophy (X-ALD). The median (95%CI) of first tier C26:0 Lyso-PC values in AGS individuals (0.43µM [0.37-0.48]) was higher than that seen in controls (0.21µM [0.21-0.21]), but lower than X-ALD individuals (0.72µM [0.59-0.84])(p<0.001). Fourteen of 19 children had elevated expression of IFN signaling on blood cards relative to controls (Sensitivity 73.7%, 95%CI 51-88%, Specificity 95%, 95% CI 78-99%) including an individual with delayed disease presentation (36months of age). All five AGS patients with negative IFN signature at birth had RNASEH2B mutations. Consistency of agreement between IFN signature in neonatal and post-natal samples was high (0.85). CONCLUSION: This suggests that inflammatory markers in AGS can be identified in the newborn period, before symptom onset. Additionally, since C26:0 Lyso-PC screening is currently used in X-ALD newborn screening panels, clinicians should be alert to the fact that AGS infants may present as false positives during X-ALD screening.


Assuntos
Doenças Autoimunes do Sistema Nervoso/sangue , Doenças Autoimunes do Sistema Nervoso/diagnóstico , Interferons/sangue , Lisofosfatidilcolinas/sangue , Triagem Neonatal/métodos , Malformações do Sistema Nervoso/sangue , Malformações do Sistema Nervoso/diagnóstico , Doenças Autoimunes do Sistema Nervoso/genética , Doenças Autoimunes do Sistema Nervoso/fisiopatologia , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Teste em Amostras de Sangue Seco/métodos , Exodesoxirribonucleases/genética , Feminino , Humanos , Lactente , Recém-Nascido , Inflamação/sangue , Inflamação/genética , Interferons/genética , Masculino , Mutação , Malformações do Sistema Nervoso/genética , Malformações do Sistema Nervoso/fisiopatologia , Fosfoproteínas/genética , Estudos Retrospectivos , Sensibilidade e Especificidade , Espectrometria de Massas em Tandem , Transcriptoma/imunologia
6.
Ann Neurol ; 79(6): 1031-1037, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27159321

RESUMO

Here we report whole exome sequencing (WES) on a cohort of 71 patients with persistently unresolved white matter abnormalities with a suspected diagnosis of leukodystrophy or genetic leukoencephalopathy. WES analyses were performed on trio, or greater, family groups. Diagnostic pathogenic variants were identified in 35% (25 of 71) of patients. Potentially pathogenic variants were identified in clinically relevant genes in a further 7% (5 of 71) of cases, giving a total yield of clinical diagnoses in 42% of individuals. These findings provide evidence that WES can substantially decrease the number of unresolved white matter cases. Ann Neurol 2016;79:1031-1037.


Assuntos
Análise Mutacional de DNA , Exoma/genética , Leucoencefalopatias/diagnóstico , Leucoencefalopatias/genética , Substância Branca/patologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Leucoencefalopatias/patologia , Masculino , Mutação , Adulto Jovem
7.
Mol Genet Metab ; 114(4): 527-36, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25684057

RESUMO

Leukodystrophies are a heterogeneous, often progressive group of disorders manifesting a wide range of symptoms and complications. Most of these disorders have historically had no etiologic or disease specific therapeutic approaches. Recently, a greater understanding of the pathologic mechanisms associated with leukodystrophies has allowed clinicians and researchers to prioritize treatment strategies and advance research in therapies for specific disorders, some of which are on the verge of pilot or Phase I/II clinical trials. This shifts the care of leukodystrophy patients from the management of the complex array of symptoms and sequelae alone to targeted therapeutics. The unmet needs of leukodystrophy patients still remain an overwhelming burden. While the overwhelming consensus is that these disorders collectively are symptomatically treatable, leukodystrophy patients are in need of advanced therapies and if possible, a cure.


Assuntos
Doenças Desmielinizantes/terapia , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/terapia , Leucodistrofia Metacromática/terapia , Leucoencefalopatias/terapia , Encefalopatias/prevenção & controle , Encefalopatias/terapia , Doenças Desmielinizantes/prevenção & controle , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/prevenção & controle , Humanos , Leucodistrofia Metacromática/prevenção & controle , Leucoencefalopatias/prevenção & controle
8.
Ann Rheum Dis ; 74(10): 1931-9, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24906636

RESUMO

OBJECTIVES: Aicardi-Goutières syndrome (AGS) is an autoimmune disorder that shares similarities with systemic lupus erythematous. AGS inflammatory responses specially target the cerebral white matter. However, it remains uncertain why the brain is the most affected organ, and little is known about the presence of autoantibodies in AGS. Here, we aim to profile specific autoantibodies in AGS and to determine whether these autoantibodies target cerebral epitopes. METHODS: Using a multiplex microarray, we assessed the spectrum of serum autoantibodies in 56 genetically confirmed patients with AGS. We investigated the presence of immunoglobulins in AGS brain specimens using immunohistochemistry and studied the reactivity of sera against brain epitopes with proteomics. RESULTS: Serum from patients exhibited high levels of IgGs against nuclear antigens (gP210, Nup62, PCNA, Ro/SSA, Sm/RNP complex, SS-A/SS-B), components of the basement membrane (entactin, laminin), fibrinogen IV and gliadin. Upon testing whether antibodies in AGS could be found in the central nervous system, IgGs were identified to target in vivo endothelial cells in vivo and astrocytes in brain sections of deceased patients with AGS. Using a proteomics approach, we were able to confirm that IgGs in serum samples from AGS patients bind epitopes present in the cerebral white matter. CONCLUSIONS: Patients with AGS produce a broad spectrum of autoantibodies unique from other autoimmune diseases. Some of these autoantibodies target endothelial cells and astrocytes in the brain of the affected patients, perhaps explaining the prominence of neurological disease in the AGS phenotype.


Assuntos
Autoanticorpos/análise , Doenças Autoimunes do Sistema Nervoso/imunologia , Encéfalo/imunologia , Malformações do Sistema Nervoso/imunologia , Adolescente , Adulto , Astrócitos/imunologia , Autoanticorpos/sangue , Autoantígenos/imunologia , Doenças Autoimunes/imunologia , Doenças Autoimunes do Sistema Nervoso/genética , Criança , Pré-Escolar , Endotélio Vascular/imunologia , Feminino , Genótipo , Humanos , Imunoglobulina G/análise , Imunoglobulina M/análise , Lactente , Recém-Nascido , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Doença Mista do Tecido Conjuntivo/imunologia , Malformações do Sistema Nervoso/genética , Proteômica/métodos , Adulto Jovem
9.
Am J Hum Genet ; 92(5): 767-73, 2013 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-23582646

RESUMO

Hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) is a rare hereditary leukoencephalopathy that was originally identified by MRI pattern analysis, and it has thus far defied all attempts at identifying the causal mutation. Only 22 cases are published in the literature to date. We performed exome sequencing on five family trios, two family quartets, and three single probands, which revealed that all eleven H-ABC-diagnosed individuals carry the same de novo single-nucleotide TUBB4A mutation resulting in nonsynonymous change p.Asp249Asn. Detailed investigation of one of the family quartets with the singular finding of an H-ABC-affected sibling pair revealed maternal mosaicism for the mutation, suggesting that rare de novo mutations that are initially phenotypically neutral in a mosaic individual can be disease causing in the subsequent generation. Modeling of TUBB4A shows that the mutation creates a nonsynonymous change at a highly conserved asparagine that sits at the intradimer interface of α-tubulin and ß-tubulin, and this change might affect tubulin dimerization, microtubule polymerization, or microtubule stability. Consistent with H-ABC's clinical presentation, TUBB4A is highly expressed in neurons, and a recent report has shown that an N-terminal alteration is associated with a heritable dystonia. Together, these data demonstrate that a single de novo mutation in TUBB4A results in H-ABC.


Assuntos
Gânglios da Base/patologia , Cerebelo/patologia , Leucoencefalopatias/genética , Modelos Moleculares , Conformação Proteica , Tubulina (Proteína)/genética , Sequência de Aminoácidos , Sequência de Bases , Cristalografia por Raios X , Exoma/genética , Feminino , Frequência do Gene , Estudos de Associação Genética , Humanos , Leucoencefalopatias/patologia , Imagem por Ressonância Magnética , Masculino , Modelos Genéticos , Dados de Sequência Molecular , Neurônios/metabolismo , Análise de Sequência de DNA , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo
10.
Neurology ; 80(11): 997-1002, 2013 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-23408864

RESUMO

OBJECTIVE: This study explores a large panel of cytokines in plasma and CSF of patients with Aicardi-Goutières syndrome (AGS) at different ages, in order to establish signatures of cytokines most predictive of AGS. METHODS: Plasma from 22 subjects with known mutations were assayed for cytokines using the Milliplex MAP Immunobead system, and compared to results from 8 age-matched normal controls. CSF of 11 additional patients with mutation-proven AGS was tested in an identical manner and compared to results from age-matched controls. Samples were banked and analysis was carried out retrospectively. RESULTS: Significant elevations were seen in FMS-related tyrosine kinase 3 ligand, IP-10, interleukin (IL)-12p40, IL-15, tumor necrosis factor α, and soluble IL 2 receptor α in both AGS patient plasma and CSF relative to controls. Additionally, this cytokine signature was able to correctly cluster 9 of 11 AGS cases based on CSF values. While most cytokines decreased exponentially with age, a subgroup including IP-10 demonstrated persistent elevation beyond early childhood. CONCLUSION: Patients with AGS exhibit plasma and CSF elevations of proinflammatory cytokines. Selected cytokines remain persistently elevated beyond the initial disease phase. This panel of proinflammatory cytokines may be considered for use as diagnostic and therapeutic markers of disease, and may permit improved understanding of disease pathogenesis.


Assuntos
Doenças Autoimunes do Sistema Nervoso/patologia , Citocinas/biossíntese , Mediadores da Inflamação/metabolismo , Malformações do Sistema Nervoso/patologia , Adolescente , Doenças Autoimunes do Sistema Nervoso/sangue , Doenças Autoimunes do Sistema Nervoso/líquido cefalorraquidiano , Biomarcadores/sangue , Biomarcadores/líquido cefalorraquidiano , Criança , Pré-Escolar , Citocinas/sangue , Citocinas/líquido cefalorraquidiano , Feminino , Humanos , Lactente , Mediadores da Inflamação/sangue , Mediadores da Inflamação/líquido cefalorraquidiano , Masculino , Malformações do Sistema Nervoso/sangue , Malformações do Sistema Nervoso/líquido cefalorraquidiano , Estudos Retrospectivos
11.
Am J Hum Genet ; 89(3): 415-23, 2011 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-21855841

RESUMO

Leukodystrophies are a heterogeneous group of inherited neurodegenerative disorders characterized by abnormal white matter visible by brain imaging. It is estimated that at least 30% to 40% of individuals remain without a precise diagnosis despite extensive investigations. We mapped tremor-ataxia with central hypomyelination (TACH) to 10q22.3-23.1 in French-Canadian families and sequenced candidate genes within this interval. Two missense and one insertion mutations in five individuals with TACH were uncovered in POLR3A, which codes for the largest subunit of RNA polymerase III (Pol III). Because these families were mapped to the same locus as leukodystrophy with oligodontia (LO) and presented clinical and radiological overlap with individuals with hypomyelination, hypodontia and hypogonadotropic hypogonadism (4H) syndrome, we sequenced this gene in nine individuals with 4H and eight with LO. In total, 14 recessive mutations were found in 19 individuals with TACH, 4H, or LO, establishing that these leukodystrophies are allelic. No individual was found to carry two nonsense mutations. Immunoblots on 4H fibroblasts and on the autopsied brain of an individual diagnosed with 4H documented a significant decrease in POLR3A levels, and there was a more significant decrease in the cerebral white matter compared to that in the cortex. Pol III has a wide set of target RNA transcripts, including all nuclear-coded tRNA. We hypothesize that the decrease in POLR3A leads to dysregulation of the expression of certain Pol III targets and thereby perturbs cytoplasmic protein synthesis. This type of broad alteration in protein synthesis is predicted to occur in other leukoencephalopathies such as hypomyelinating leukodystrophy-3, caused by mutations in aminoacyl-tRNA synthetase complex-interacting multifunctional protein 1 (AIMP1).


Assuntos
Cromossomos Humanos Par 10/genética , Predisposição Genética para Doença/genética , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/genética , Modelos Moleculares , RNA Polimerase III/genética , Tremor/genética , Sequência de Aminoácidos , Sequência de Bases , Genes Recessivos/genética , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/patologia , Humanos , Dados de Sequência Molecular , Mutagênese Insercional/genética , Mutação de Sentido Incorreto/genética , Quebeque , RNA Polimerase III/química , Análise de Sequência de DNA , Tremor/patologia
12.
Methods Mol Biol ; 694: 365-77, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21082445

RESUMO

This chapter provides a detailed description of a method used to study temporal changes in the endoplasmic reticulum (ER) proteome of fibroblast cells exposed to ER stress agents (tunicamycin and thapsigargin). Differential stable isotope labeling by amino acids in cell culture (SILAC) is used in combination with crude ER fractionation, SDS-PAGE and LC-MS/MS to define altered protein expression in tunicamycin or thapsigargin treated cells versus untreated cells. Treated and untreated cells are harvested at different time points, mixed at a 1:1 ratio and processed for ER fractionation. Samples containing labeled and unlabeled proteins are separated by SDS-PAGE, bands are digested with trypsin and the resulting peptides analyzed by LC-MS/MS. Proteins are identified using Bioworks software and the Swiss-Prot database, whereas ratios of protein expression between treated and untreated cells are quantified using ZoomQuant software. Data visualization is facilitated by GeneSpring software.


Assuntos
Proteoma/análise , Proteômica/métodos , Aminoácidos/metabolismo , Células Cultivadas , Eletroforese em Gel de Poliacrilamida , Retículo Endoplasmático/patologia , Humanos , Marcação por Isótopo , Espectrometria de Massas , Peptídeos/isolamento & purificação , Proteínas/análise , Padrões de Referência , Estresse Fisiológico , Frações Subcelulares/metabolismo , Fatores de Tempo
13.
Brain Res ; 1200: 138-45, 2008 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-18289516

RESUMO

Intrauterine inflammation has been implicated in developmental brain injuries, including the development of periventricular leukomalacia (PVL) and cerebral palsy (CP). Previous studies in our rat model of intrauterine inflammation demonstrated apoptotic cell death in fetal brains within the first 5 days after lipopolysaccharide (LPS) administration to mothers and eventual dysmyelination. Cysteine-containing, aspartate-specific proteases, or caspases, are proteins involved with apoptosis through both intracellular (intrinsic pathway) and extracellular (extrinsic pathway) mechanisms. We hypothesized that cell death in our model would occur mainly via activation of the extrinsic pathway. We further hypothesized that Fas, a member of the tumor necrosis factor receptor (TNFR) superfamily, would be increased and the death inducing signaling complex (DISC) would be detectable. Pregnant rats were injected intracervically with LPS at E15 and immunoblotting, immunohistochemical and immunoprecipitation analyses were performed. The presence of the activated form of the effector caspase (caspase-3) was observed 24 h after LPS administration. Caspase activity assays demonstrated rapid increases in (i) caspases-9 and -10 within 1 h, (ii) caspase-8 at 2 h and (iii) caspase-3 at 4 h. At 24 h after LPS, activated caspase-3(+)/Fas(+) cells were observed within the developing white matter. Lastly, the DISC complex (caspase-8, Fas and Fas-associated death domain (FADD)) was observed within 30 min by immunoprecipitation. Apoptosis in our model occurs via both extrinsic and intrinsic pathways, and activation of Fas may play a role. Understanding the mechanisms of cell death in models of intrauterine inflammation may affect development of future strategies to mitigate these injuries in children.


Assuntos
Apoptose , Caspases/metabolismo , Encefalite/enzimologia , Doenças Fetais/enzimologia , Degeneração Neural/enzimologia , Receptor fas/metabolismo , Animais , Paralisia Cerebral/enzimologia , Paralisia Cerebral/etiologia , Paralisia Cerebral/fisiopatologia , Proteínas Adaptadoras de Sinalização de Receptores de Domínio de Morte/metabolismo , Modelos Animais de Doenças , Encefalite/induzido quimicamente , Encefalite/patologia , Ativação Enzimática , Proteína de Domínio de Morte Associada a Fas/metabolismo , Feminino , Doenças Fetais/induzido quimicamente , Doenças Fetais/patologia , Humanos , Recém-Nascido , Mediadores da Inflamação , Isoenzimas/metabolismo , Leucomalácia Periventricular/enzimologia , Leucomalácia Periventricular/etiologia , Leucomalácia Periventricular/fisiopatologia , Lipopolissacarídeos , Degeneração Neural/induzido quimicamente , Degeneração Neural/etiologia , Gravidez , Ratos , Transdução de Sinais
14.
J Cereb Blood Flow Metab ; 28(2): 341-53, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17637705

RESUMO

Vascular cognitive impairment (VCI) is the second most prevalent type of dementia in the world. The white matter damage that characterizes the common subcortical ischemic form of VCI can be modeled by ligating both common carotid arteries in the Wistar rat to induce protracted cerebral hypoperfusion. In this model, we find that repetitive intranasal administration of recombinant E-selectin to induce mucosal tolerance and to target immunomodulation to activating blood vessels potently suppresses both white matter (and possibly gray matter) damage and markers of vessel activation (tumor necrosis factor and E-selectin); it also preserves behavioral function in T-maze spontaneous alternation, T-maze spatial discrimination memory retention, and object recognition tests. Immunomodulation may be an effective novel strategy to prevent progression of VCI.


Assuntos
Encéfalo/patologia , Demência Vascular/prevenção & controle , Selectina E/farmacologia , Tolerância Imunológica/fisiologia , Imunidade nas Mucosas/fisiologia , Transtornos da Memória/prevenção & controle , Animais , Demência Vascular/patologia , Demência Vascular/fisiopatologia , Discriminação (Psicologia)/efeitos dos fármacos , Feminino , Hipersensibilidade Tardia/fisiopatologia , Tolerância Imunológica/efeitos dos fármacos , Imunidade nas Mucosas/efeitos dos fármacos , Imunoensaio , Fatores Imunológicos/farmacologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Transtornos da Memória/patologia , Transtornos da Memória/fisiopatologia , Ratos , Ratos Wistar , Recognição (Psicologia)/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismo
15.
Ment Retard Dev Disabil Res Rev ; 12(2): 105-12, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16807890

RESUMO

Inflammation during the perinatal period has become a recognized risk factor for developmental brain injuries over the past decade or more. To fully understand the relationship between inflammation and brain development, a comprehensive knowledge about the immune system within the brain is essential. Microglia are resident immune cells within the central nervous system and play a critical role in the development of an inflammatory response within the brain. Microglia are critically involved with both the innate and adaptive immune system, regulating inflammation and cell damage within the brain via activation of Toll-like receptors, production of cytokines, and a myriad of other intracellular and intercellular processes. In this article, microglial physiology is reviewed along with the role of microglia in developmental brain injuries in humans and animal models. Last, microglial functions within the innate and adaptive immune system will be summarized. Understanding the processes of inflammation and microglial activation is critical for formulating effective preventative and therapeutic strategies for developmental brain injuries.


Assuntos
Encefalite/epidemiologia , Encefalite/patologia , Hipóxia-Isquemia Encefálica/epidemiologia , Hipóxia-Isquemia Encefálica/patologia , Microglia/patologia , Biomarcadores , Quimiocinas/metabolismo , Encefalite/metabolismo , Feminino , Humanos , Hipóxia-Isquemia Encefálica/metabolismo , Recém-Nascido , Microglia/metabolismo , Complicações do Trabalho de Parto , Fagocitose/fisiologia , Gravidez , Complicações na Gravidez
16.
J Cereb Blood Flow Metab ; 26(10): 1323-31, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16511503

RESUMO

The serine-threonine protein kinase Akt has been identified as an important mediator of cell survival able to counteract apoptotic stimuli. However, hibernation, a model of natural tolerance to cerebral ischemia, is associated with downregulation of Akt. We previously established a model of ischemic tolerance in a PC12 cell line and using this model we now addressed the question whether ischemic tolerance also downregulates Akt in PC12 cells. Kinetic studies showed decreased Akt phosphorylation in tolerized cells. Similarly, phosphorylated levels of three major targets of Akt and well-known proapoptotic factors, the glycogen synthase kinase 3 (GSK-3), a Forkhead family member, FoxO4, and the protein murine double minute 2 (MDM2), all inactivated upon phosphorylation by Akt, were decreased in preconditioned cells. In addition, pharmacological blockade of the phosphoinositide 3-kinase (PI3K)/Akt pathway reduced cell death induced by oxygen and glucose deprivation (OGD) and increased the protective effect of preconditioning (PC). Furthermore, decreasing availability of P-Akt by transfecting PC12 cells with constructs of inactive Akt also resulted in protection against OGD and potentiation of the protective effect of PC. Depending on the environment, GSK-3, FOXO-4, and MDM2 can trigger apoptotic responses or cell cycle arrest, and thus, in a situation of reduced energy, driving the cells into a state of quiescence might be neuroprotective. This work suggests that in the context of tolerance downregulation of Akt is beneficial.


Assuntos
Precondicionamento Isquêmico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Regulação para Baixo/efeitos dos fármacos , Ativação Enzimática/genética , Glucose/farmacologia , Quinase 3 da Glicogênio Sintase/metabolismo , Camundongos , Mutação/genética , Oxigênio/farmacologia , Células PC12 , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Ratos , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos
17.
Glia ; 51(4): 266-78, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15816038

RESUMO

Many studies have shown that pigment epithelium-derived factor (PEDF) has neurotrophic effects on retinal cells and hippocampal, spinal cord, and cerebellar granule cell neurons, but much less work has examined the effects of PEDF on glia. In this study, we show that PEDF changes microglial morphology within 1 h of exposure, to a more deactivated form, while having no effect on the expression of such activation markers as OX-42 and ED-1. In contrast, urea activates acid phosphatase, and PEDF blocks that activation. PEDF also activates NFkappaB, accompanied by the induction of mRNAs and proteins for the chemokines macrophage inflammatory protein-1alpha (MIP-1alpha, MIP-2, and MIP-3alpha. All the chemokines stimulate acid phosphatase activity, and high doses of MIP-2 and MIP-3alpha), alter the morphology of the microglia at 1 h after treatment. These results suggest that the use of PEDF for clinical treatments, such as for retinal neovascularization, brain injury, or ischemia, should be undertaken with caution because of the possibility of induction of inflammation caused by microglial or other immune cell migration in response to the chemokines induced by PEDF.


Assuntos
Encefalopatias/tratamento farmacológico , Quimiocinas/metabolismo , Proteínas do Olho/farmacologia , Microglia/efeitos dos fármacos , Fatores de Crescimento Neural/farmacologia , Serpinas/farmacologia , Fosfatase Ácida/antagonistas & inibidores , Fosfatase Ácida/metabolismo , Transporte Ativo do Núcleo Celular/efeitos dos fármacos , Transporte Ativo do Núcleo Celular/fisiologia , Animais , Encefalopatias/imunologia , Encefalopatias/fisiopatologia , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Forma Celular/efeitos dos fármacos , Forma Celular/fisiologia , Células Cultivadas , Quimiocina CCL3 , Quimiocina CCL4 , Quimiocinas/imunologia , Quimiocinas/farmacologia , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Gliose/induzido quimicamente , Gliose/imunologia , Gliose/fisiopatologia , Mediadores da Inflamação/farmacologia , Proteínas Inflamatórias de Macrófagos/genética , Proteínas Inflamatórias de Macrófagos/metabolismo , Microglia/imunologia , NF-kappa B/efeitos dos fármacos , NF-kappa B/genética , NF-kappa B/metabolismo , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/fisiologia , Ureia/farmacologia
18.
J Neurosci Res ; 77(5): 642-52, 2004 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-15352210

RESUMO

Microarray analyses demonstrated that a variety of genes was affected by treatment of cerebellar granule cell neurons with the neurotrophic factor pigment epithelium-derived factor (PEDF). The genes for neurotrophins, glial cell-derived neurotrophic factor (GDNF), and their receptors were regulated differentially in immature versus mature neurons; however, nerve growth factor (NGF), neurotrophin (NT)-3, and GDNF did not contribute to the protective effect of PEDF. Brain-derived neurotrophic factor (BDNF) seemed capable of inducing apoptosis, because a blocking antibody enhanced the protective effect of PEDF. In addition, PEDF exposure also stimulated expression of several cytokine and chemokine genes. Removal of the less than 1% of microglia in the cultures by treatment with L-leucine methyl ester, combined with enzyme-linked immunosorbent assays (ELISAs), demonstrated that the cerebellar granule cells constitutively produce three chemokines, macrophage inflammatory protein (MIP)-1alpha, MIP-2, and MIP-3alpha, whose production is enhanced further by treatment with PEDF. Blocking antibodies to each of the chemokines was protective under control conditions, suggesting that they may contribute to the "natural" apoptosis occurring in the cultures, and enhanced the effects of PEDF. Although PEDF enhanced production of all three chemokines, the blocking antibodies did not increase its protective effect against induced apoptosis. These results suggest that although PEDF enhances expression of other neurotrophic factors or chemokines, it does not exert its neuroprotective effect on cerebellar granule cells through their production.


Assuntos
Cerebelo/citologia , Quimiocinas/metabolismo , Citocinas/metabolismo , Proteínas do Olho/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Fatores de Crescimento Neural/metabolismo , Fatores de Crescimento Neural/farmacologia , Neurônios/efeitos dos fármacos , Serpinas/farmacologia , Animais , Animais Recém-Nascidos , Anticorpos/farmacologia , Apoptose/efeitos dos fármacos , Células Cultivadas , Quimiocinas/imunologia , Citocinas/imunologia , Interações de Medicamentos , Ensaio de Imunoadsorção Enzimática/métodos , Microglia/efeitos dos fármacos , Microglia/metabolismo , Fatores de Crescimento Neural/genética , Neurônios/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos/métodos , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA