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1.
Lab Med ; 54(5): 546-549, 2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36864546

RESUMO

TEMPI syndrome is a new and poorly understood disease that is currently considered a type of plasma cell neoplasm with paraneoplastic manifestations. The TEMPI acronym defines the hallmarks of the syndrome: T for telangiectasia; E for erythrocytosis with elevated erythropoietin; M, monoclonal gammopathy; P, perinephric collections; and I, intrapulmonary shunting. Due to the marked erythrocytosis as the most common presenting feature, TEMPI is often misdiagnosed as polycythemia vera. However, unlike polycythemia vera, TEMPI is not associated with a JAK2 mutation. The pathogenesis of TEMPI syndrome is unknown, although a few hypothetical disease mechanisms have been previously discussed. Here we present a new case of TEMPI syndrome, discuss results of a next-generation sequencing (NGS) panel covering 1,425 known cancer-related genes, and review the current literature with focus on an update of the genetics of TEMPI syndrome. This is the first report of TEMPI that includes results of comprehensive NGS testing.


Assuntos
Paraproteinemias , Policitemia Vera , Policitemia , Telangiectasia , Humanos , Policitemia/diagnóstico , Policitemia/genética , Policitemia Vera/genética , Paraproteinemias/patologia , Telangiectasia/diagnóstico , Telangiectasia/patologia , Sequenciamento de Nucleotídeos em Larga Escala
2.
JCO Clin Cancer Inform ; 6: e2100113, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35025668

RESUMO

PURPOSE: To better use genetic testing, which is used by clinicians to explain the molecular mechanism of disease and to suggest clinical actionability and new treatment options, clinical next-generation sequencing (NGS) laboratories must send the results into reports in PDF and discrete data element format (HL7). Although most clinical diagnostic tests have set molecular markers tested and have a set range of values or a binary result (positive or negative), the NGS genetic test could examine hundreds or thousands of genes with no predefined list of variants. Although there are some commercial and open-source tools for clinically reporting genomics results for oncology testing, they often lack necessary features. METHODS: Using several available software tools for data storage including MySQL and MongoDB, database querying with Python, and a web-based user application using JAVA and JAVA script, we have developed a tool to store and query complex genomics and demographics data, which can be manually curated and reported by the user. RESULTS: We have developed a tool, Annotation SoftWare for Electronic Reporting (ANSWER), that can allow molecular pathologists to (1) filter variants to find those meeting quality control metrics in the genes that are clinically actionable by diagnosis; (2) visualize variants using data generated in the bioinformatics analysis; (3) create annotations that can be reused in future reports with association specific to the gene, variant, or diagnosis; (4) select variants and annotations that should be reported to match the details of the case; and (5) generate a report that includes demographics, reported variants, clinical actionability annotation, and references that can be exported into PDF or HL7 format, which can be electronically sent to an electronic health record. CONCLUSION: ANSWER is a tool that can be installed locally and is designed to meet the clinical reporting needs of a clinical oncology NGS laboratory for reporting.


Assuntos
Variação Genética , Software , Biologia Computacional/métodos , Eletrônica , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos
3.
J Neuropathol Exp Neurol ; 80(12): 1092-1098, 2021 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-34850045

RESUMO

A primitive neuronal component is a feature of some glioblastomas but defining molecular alterations of this histologic variant remains uncertain. We performed next-generation sequencing of 1500 tumor related genes on tissue from 9 patients with glioblastoma with a primitive component (G/PN) and analyzed 27 similar cases from the Cancer Genome Atlas (TCGA) dataset. Alterations in the RB pathway were identified in all of our patients' tumors and 81% of TCGA tumors with the retinoblastoma tumor suppressor gene (RB1) commonly affected. Although RB1 mutations were observed in some conventional glioblastomas, the allelic fractions of these mutations were significantly higher in tumors with a primitive neuronal component in both our and TCGA cohorts (median, 72% vs 25%, p < 0.001 and 80% vs 40%, p < 0.02, respectively). Further, in 78% of patients in our cohort, RB expression was lost by immunohistochemistry. Our findings indicate that alterations in the RB pathway are common in G/PNs and suggest that inactivation of RB1 may be a driving mechanism for the phenotype.


Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Glioblastoma/genética , Glioblastoma/patologia , Proteínas de Ligação a Retinoblastoma/genética , Ubiquitina-Proteína Ligases/genética , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação
4.
Nat Methods ; 14(10): 967-970, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28869755

RESUMO

Advances in single-cell technologies have highlighted the prevalence and biological significance of cellular heterogeneity. A critical question researchers face is how to design experiments that faithfully capture the true range of heterogeneity from samples of cellular populations. Here we develop a data-driven approach, illustrated in the context of image data, that estimates the sampling depth required for prospective investigations of single-cell heterogeneity from an existing collection of samples.


Assuntos
Adenocarcinoma/patologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Neoplasias Pulmonares/patologia , Análise de Célula Única/métodos , Biomarcadores Tumorais , Técnicas de Cultura de Células , Linhagem Celular , Regulação Neoplásica da Expressão Gênica , Humanos
5.
J Neuropathol Exp Neurol ; 76(10): 874-882, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28922848

RESUMO

Silent subtype III pituitary adenomas (SS-3) are clinically nonfunctional adenomas that are more aggressive in terms of invasion and risk of recurrence than their conventional null cell counterparts. We previously showed that these tumors can be distinguished by immunohistochemistry based on the identification of a markedly enlarged and fragmented Golgi apparatus. To understand the molecular correlates of differential aggressiveness, we performed whole transcriptome sequencing (RNAseq) on 4 SS-3 and 4 conventional null cell adenomas. The genes that were highly upregulated in all the SS-3 adenomas included 2 secreted proteins involved in the suppression of T-lymphocyte activity, i.e., ARG2 (multiple testing adjusted padj = 1.5 × 10-3) and SEMA3A (padj = 3.3 × 10-3). Highly downregulated genes in all the SS-3 adenomas included HLA-B (padj = 3.3 × 10-6), suggesting reduced antigen presentation by the adenoma to cytotoxic T-cells. Quantitative RT-PCR of these genes performed on the adenoma samples supported the RNAseq results. We also found a relative decrease in the overall concentration of T-lymphocytes in the SS-3 tumors. These results suggest that SS-3 adenomas actively suppress the immune system and raise the possibility that they may be treatable with immune checkpoint inhibitors or nonspecific cancer immunotherapies.


Assuntos
Adenoma , Agressão/fisiologia , Imunidade Inata , Linfócitos/patologia , Neoplasias Hipofisárias , Adenoma/genética , Adenoma/imunologia , Adenoma/fisiopatologia , Adulto , Idoso , Arginase/genética , Arginase/metabolismo , Complexo CD3/metabolismo , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Antígenos HLA-B/genética , Antígenos HLA-B/metabolismo , Humanos , Linfócitos/metabolismo , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/imunologia , Neoplasias Hipofisárias/fisiopatologia , RNA Mensageiro/metabolismo , Estudos Retrospectivos , Semaforina-3A/genética , Semaforina-3A/metabolismo , Transdução de Sinais/genética
6.
Cell Rep ; 19(13): 2756-2770, 2017 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-28658623

RESUMO

Although NOD2 is the major inflammatory bowel disease susceptibility gene, its role in colorectal tumorigenesis is poorly defined. Here, we show that Nod2-deficient mice are highly susceptible to experimental colorectal tumorigenesis independent of gut microbial dysbiosis. Interestingly, the expression of inflammatory genes and the activation of inflammatory pathways, including NF-κB, ERK, and STAT3 are significantly higher in Nod2-/- mouse colons during colitis and colorectal tumorigenesis, but not at homeostasis. Consistent with higher inflammation, there is greater proliferation of epithelial cells in hyperplastic regions of Nod2-/- colons. In vitro studies demonstrate that, while NOD2 activates the NF-κB and MAPK pathways in response to MDP, it inhibits TLR-mediated activation of NF-κB and MAPK. Notably, NOD2-mediated downregulation of NF-κB and MAPK is associated with the induction of IRF4. Taken together, NOD2 plays a critical role in the suppression of inflammation and tumorigenesis in the colon via downregulation of the TLR signaling pathways.


Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Proteína Adaptadora de Sinalização NOD2/genética , Proteína Adaptadora de Sinalização NOD2/metabolismo , Receptores Toll-Like/metabolismo , Animais , Carcinogênese , Regulação para Baixo , Feminino , Fatores Reguladores de Interferon/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , NF-kappa B/metabolismo , Transdução de Sinais , Receptores Toll-Like/genética
8.
Immunol Cell Biol ; 94(7): 701-8, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27001469

RESUMO

Eosinophils contribute to immune regulation and wound healing/fibrosis in various diseases, including asthma. Growing appreciation for the role of activin A in such processes led us to hypothesize that eosinophils are a source of this transforming growth factor-ß superfamily member. Tumor necrosis factor-α (TNF) induces activin A by other cell types and is often present at the site of allergic inflammation along with the eosinophil-activating common ß (ßc) chain-signaling cytokines (interleukin (IL)-5, IL-3, granulocyte-macrophages colony-stimulating factor (GM-CSF)). Previously, we established that the combination of TNF plus a ßc chain-signaling cytokine synergistically induces eosinophil synthesis of the remodeling enzyme matrix metalloproteinase-9. Therefore, eosinophils were stimulated ex vivo by these cytokines and in vivo through an allergen-induced airway inflammatory response. In contrast to IL-5+TNF or GM-CSF+TNF, the combination of IL-3+TNF synergistically induced activin A synthesis and release by human blood eosinophils. IL-3+TNF enhanced activin A mRNA stability, which required sustained signaling of pathways downstream of p38 and extracellular signal-regulated kinase mitogen-activated protein kinases. In vivo, following segmental airway allergen challenge of subjects with mild allergic asthma, activin A mRNA was upregulated in airway eosinophils compared with circulating eosinophils, and ex vivo, circulating eosinophils tended to release more activin A in response to IL-3+TNF. These data provide evidence that eosinophils release activin A and that this function is enhanced when eosinophils are present in an allergen-induced inflammatory environment. Moreover, these data provide the first evidence for posttranscriptional control of activin A mRNA. We propose that an environment rich in IL-3+TNF will lead to eosinophil-derived activin A, which has an important role in regulating inflammation and/or fibrosis.


Assuntos
Ativinas/metabolismo , Eosinófilos/metabolismo , Interleucina-3/farmacologia , Estabilidade de RNA , Fator de Necrose Tumoral alfa/farmacologia , Adulto , Ativação Enzimática/efeitos dos fármacos , Eosinófilos/efeitos dos fármacos , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Humanos , Hipersensibilidade/enzimologia , Hipersensibilidade/imunologia , Hipersensibilidade/patologia , Subunidades beta de Inibinas/genética , Subunidades beta de Inibinas/metabolismo , Interleucina-5/farmacologia , Cinética , Masculino , Pessoa de Meia-Idade , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Estabilidade de RNA/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Adulto Jovem
9.
J Immunol ; 195(6): 2529-39, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26276876

RESUMO

IL-5 is a major therapeutic target to reduce eosinophilia. However, all of the eosinophil-activating cytokines, such as IL-5, IL-3, and GM-CSF, are typically present in atopic diseases, including allergic asthma. As a result of the functional redundancy of these three cytokines on eosinophils and the loss of IL-5R on airway eosinophils, it is important to take IL-3 and GM-CSF into account to efficiently reduce tissue eosinophil functions. Moreover, these three cytokines signal through a common ß-chain receptor but yet differentially affect protein production in eosinophils. Notably, the increased ability of IL-3 to induce the production of proteins, such as semaphorin-7A, without affecting mRNA levels suggests a unique influence of IL-3 on translation. The purpose of this study was to identify the mechanisms by which IL-3 distinctively affects eosinophil function compared with IL-5 and GM-CSF, with a focus on protein translation. Peripheral blood eosinophils were used to study intracellular signaling and protein translation in cells activated with IL-3, GM-CSF, or IL-5. We establish that, unlike GM-CSF or IL-5, IL-3 triggers prolonged signaling through activation of ribosomal protein S6 (RPS6) and the upstream kinase 90-kDa ribosomal S6 kinase (p90S6K). Blockade of p90S6K activation inhibited phosphorylation of RPS6 and IL-3-enhanced semaphorin-7A translation. Furthermore, in an allergen-challenged environment, in vivo phosphorylation of RPS6 and p90S6K was enhanced in human airway compared with circulating eosinophils. Our findings provide new insights into the mechanisms underlying differential activation of eosinophils by IL-3, GM-CSF, and IL-5. These observations identify IL-3 and its downstream intracellular signals as novel targets that should be considered to modulate eosinophil functions.


Assuntos
Eosinófilos/fisiologia , Interleucina-3/imunologia , Proteínas Quinases S6 Ribossômicas/metabolismo , Proteína S6 Ribossômica/metabolismo , Asma/imunologia , Células Cultivadas , Ativação Enzimática , Eosinofilia/imunologia , Eosinófilos/citologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Humanos , Hipersensibilidade/imunologia , Interleucina-5/imunologia , Subunidade alfa de Receptor de Interleucina-5/metabolismo , Fosforilação , RNA Mensageiro/biossíntese , Proteína S6 Ribossômica/genética , Proteínas Quinases S6 Ribossômicas/antagonistas & inibidores , Semaforinas/biossíntese , Semaforinas/genética , Transdução de Sinais/genética
10.
Nat Commun ; 2: 4802, 2014 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-25190313

RESUMO

Wilms tumour is the most common childhood kidney cancer. Here we report the whole-exome sequencing of 44 Wilms tumours, identifying missense mutations in the microRNA (miRNA)-processing enzymes DROSHA and DICER1, and novel mutations in MYCN, SMARCA4 and ARID1A. Examination of tumour miRNA expression, in vitro processing assays and genomic editing in human cells demonstrates that DICER1 and DROSHA mutations influence miRNA processing through distinct mechanisms. DICER1 RNase IIIB mutations preferentially impair processing of miRNAs deriving from the 5'-arm of pre-miRNA hairpins, while DROSHA RNase IIIB mutations globally inhibit miRNA biogenesis through a dominant-negative mechanism. Both DROSHA and DICER1 mutations impair expression of tumour-suppressing miRNAs, including the let-7 family, important regulators of MYCN, LIN28 and other Wilms tumour oncogenes. These results provide new insights into the mechanisms through which mutations in miRNA biogenesis components reprogramme miRNA expression in human cancer and suggest that these defects define a distinct subclass of Wilms tumours.


Assuntos
RNA Helicases DEAD-box/genética , Neoplasias Renais/genética , MicroRNAs/metabolismo , Ribonuclease III/genética , Tumor de Wilms/genética , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Células HEK293 , Humanos , Lactente , Masculino , Mutação de Sentido Incorreto , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA
11.
J Immunol ; 190(10): 4937-45, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23606538

RESUMO

Abnormally long-lived eosinophils (Eos) are the major inflammatory component of allergic responses in the lungs of active asthmatics. Eos recruited to the airways after allergen exposure produce and respond to IL-5 and GM-CSF, enhancing their survival. Prosurvival signaling activates Pin1, a peptidyl-prolyl cis-trans isomerase that binds to Bax and prevents its activation. How long-lived Eos, despite the continued presence of GM-CSF or IL-5, eventually undergo apoptosis to end allergic inflammation remains unclear. In this study, we show that Pin1 location, activity, and protein interactions are jointly influenced by Fas and the prosurvival cytokine IL-5. Fas signaling strongly induced the phosphorylation of FADD at Ser(194) and Pin1 at Ser(16), as well as their nuclear accumulation. Phospho-mimic Ser(194)Glu FADD mutants accelerated Eos apoptosis compared with wild-type or Ser(194)Ala mutants. Downstream of FADD phosphorylation, caspase 8, 9, and 3 cleavage, as well as Eos apoptosis induced by Fas, were reduced by constitutively active Pin1 and enhanced by Pin1 inhibition. Pin1 was activated by IL-5, whereas simultaneous IL-5 and anti-Fas treatment modestly reduced peptidyl isomerase activity but induced Pin1 to associate with FADD after its phosphorylation at Ser(194). Mechanistically, Pin1-mediated isomerization facilitated the subsequent dephosphorylation of Ser(194) FADD and maintenance of cytoplasmic location. In vivo-activated bronchoalveolar Eos obtained after allergen challenge showed elevated survival and Pin1 activity that could be reversed by anti-Fas. Therefore, our data suggest that Pin1 is a critical link between FADD-mediated cell death and IL-5-mediated prosurvival signaling.


Assuntos
Apoptose , Eosinófilos/metabolismo , Proteína de Domínio de Morte Associada a Fas/metabolismo , Interleucina-5/metabolismo , Peptidilprolil Isomerase/metabolismo , Asma/imunologia , Asma/metabolismo , Caspase 3/metabolismo , Caspase 8/metabolismo , Caspase 9/metabolismo , Células Cultivadas , Ativação Enzimática , Eosinófilos/imunologia , Humanos , Peptidilprolil Isomerase de Interação com NIMA , Peptidil Transferases/metabolismo , Fosforilação , Transdução de Sinais , Receptor fas/imunologia , Receptor fas/metabolismo
12.
Proc Natl Acad Sci U S A ; 109(21): 8149-54, 2012 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-22566623

RESUMO

Nuclear protein peptidyl-prolyl isomerase Pin1-mediated prolyl isomerization is an essential and novel regulatory mechanism for protein phosphorylation. Therefore, tight regulation of Pin1 localization and catalytic activity is crucial for its normal nuclear functions. Pin1 is commonly dysregulated during oncogenesis and likely contributes to these pathologies; however, the mechanism(s) by which Pin1 catalytic activity and nuclear localization are increased is unknown. Here we demonstrate that mixed-lineage kinase 3 (MLK3), a MAP3K family member, phosphorylates Pin1 on a Ser138 site to increase its catalytic activity and nuclear translocation. This phosphorylation event drives the cell cycle and promotes cyclin D1 stability and centrosome amplification. Notably, Pin1 pSer138 is significantly up-regulated in breast tumors and is localized in the nucleus. These findings collectively suggest that the MLK3-Pin1 signaling cascade plays a critical role in regulating the cell cycle, centrosome numbers, and oncogenesis.


Assuntos
Transporte Ativo do Núcleo Celular/fisiologia , Neoplasias da Mama/metabolismo , Centrossomo/metabolismo , MAP Quinase Quinase Quinases/metabolismo , Peptidilprolil Isomerase/metabolismo , Transdução de Sinais/fisiologia , Neoplasias da Mama/genética , Catálise , Ciclo Celular/fisiologia , Núcleo Celular/metabolismo , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Ciclina D1/metabolismo , Feminino , Proteínas de Fluorescência Verde/genética , Células HEK293 , Células HeLa , Humanos , MAP Quinase Quinase Quinases/genética , Peptidilprolil Isomerase de Interação com NIMA , Peptidilprolil Isomerase/genética , Fosforilação/fisiologia , Serina/metabolismo , MAP Quinase Quinase Quinase 11 Ativada por Mitógeno
13.
J Vis Exp ; (55)2011 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-21946781

RESUMO

Synaptoneurosomes (SNs) are obtained after homogenization and fractionation of mouse brain cortex. They are resealed vesicles or isolated terminals that break away from axon terminals when the cortical tissue is homogenized. The SNs retain pre- and postsynaptic characteristics, which makes them useful in the study of synaptic transmission. They retain the molecular machinery used in neuronal signaling and are capable of uptake, storage, and release of neurotransmitters. The production and isolation of active SNs can be problematic using medias like Ficoll, which can be cytotoxic and require extended centrifugation due to high density, and filtration and centrifugation methods, which can result in low activity due to mechanical damage of the SNs. However, the use of discontinuous Percoll-sucrose density gradients to isolate SNs provides a rapid method to produce good yields of translationally active SNs. The Percoll-sucrose gradient method is quick and gentle as it employs isotonic conditions, has fewer and shorter centrifugation spins and avoids centrifugation steps that pellet SNs and cause mechanical damage.


Assuntos
Centrifugação com Gradiente de Concentração/métodos , Córtex Cerebral/citologia , Animais , Córtex Cerebral/química , Camundongos , Neurônios/química , Neurônios/citologia , Povidona/química , Dióxido de Silício/química , Sacarose/química , Transmissão Sináptica , Sinaptossomos/química
14.
Blood ; 116(26): 5795-802, 2010 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-20956805

RESUMO

Neutrophils play a key role in host defense by releasing reactive oxygen species (ROS). However, excessive ROS production by neutrophil nicotinamide adenine dinucleotide phosphate (NADPH) oxidase can damage bystander tissues, thereby contributing to inflammatory diseases. Tumor necrosis factor-α (TNF-α), a major mediator of inflammation, does not activate NADPH oxidase but induces a state of hyperresponsiveness to subsequent stimuli, an action known as priming. The molecular mechanisms by which TNF-α primes the NADPH oxidase are unknown. Here we show that Pin1, a unique cis-trans prolyl isomerase, is a previously unrecognized regulator of TNF-α-induced NADPH oxidase hyperactivation. We first showed that Pin1 is expressed in neutrophil cytosol and that its activity is markedly enhanced by TNF-α. Inhibition of Pin1 activity with juglone or with a specific peptide inhibitor abrogated TNF-α-induced priming of neutrophil ROS production induced by N-formyl-methionyl-leucyl-phenylalanine peptide (fMLF). TNF-α enhanced fMLF-induced Pin1 and p47phox translocation to the membranes and juglone inhibited this process. Pin1 binds to p47phox via phosphorylated Ser345, thereby inducing conformational changes that facilitate p47phox phosphorylation on other sites by protein kinase C. These findings indicate that Pin1 is critical for TNF-α-induced priming of NADPH oxidase and for excessive ROS production. Pin1 inhibition could potentially represent a novel anti-inflammatory strategy.


Assuntos
NADPH Oxidases/metabolismo , Neutrófilos/efeitos dos fármacos , Peptidilprolil Isomerase/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Western Blotting , Membrana Celular/metabolismo , Citosol/metabolismo , Humanos , N-Formilmetionina Leucil-Fenilalanina/farmacologia , NADPH Oxidases/química , Peptidilprolil Isomerase de Interação com NIMA , Naftoquinonas/farmacologia , Neutrófilos/enzimologia , Fosforilação , Transporte Proteico , Espécies Reativas de Oxigênio/metabolismo
15.
J Alzheimers Dis ; 19(1): 179-89, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20061637

RESUMO

As one of the dominant amyloid-beta peptide (Abeta) proteases, neprilysin (NEP) plays a crucial role in maintaining a physiologic balance between Abeta production and catabolism. We have previously shown that NEP is modified by 4-hydroxynonenal (HNE) adducts, resulting in decreased activity in the brain of AD patients and cultured cells. In order to determine whether antioxidants can rescue NEP, SH-SY5Y cells were treated with HNE or Abeta, together with N-acetylcysteine for 24 hours, prior to analysis of NEP protein levels, activity, and oxidative modifications. Intracellular NEP developed HNE adducts after 24 hours of HNE or Abeta treatment as determined by immunoprecipitation, immunoblotting, and double immunofluorescence staining. N-acetylcysteine at 10 to 100 microM alleviated HNE adduction after HNE or Abeta treatment. In keeping with previous reports, HNE-modified NEP showed decreased catalytic activity. The present study demonstrates that antioxidants can be used to spare NEP from oxidative modification, suggesting a potential mechanism underlying the neuroprotective effects of antioxidants in aging or Alzheimer's disease.


Assuntos
Acetilcisteína/farmacologia , Aldeídos/farmacologia , Peptídeos beta-Amiloides/farmacologia , Neprilisina/antagonistas & inibidores , Neprilisina/metabolismo , Fragmentos de Peptídeos/farmacologia , Envelhecimento/efeitos dos fármacos , Envelhecimento/metabolismo , Envelhecimento/patologia , Aldeídos/antagonistas & inibidores , Peptídeos beta-Amiloides/antagonistas & inibidores , Antioxidantes/farmacologia , Linhagem Celular Tumoral , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Humanos , Neprilisina/fisiologia , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/antagonistas & inibidores , Inibidores de Proteases/farmacologia
16.
J Alzheimers Dis ; 17(3): 489-501, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19363254

RESUMO

The cerebral accumulation of amyloid-beta (Abeta) is a consistent feature of and likely contributor to the development of Alzheimer's disease (AD). In addition to dysregulated production, increasing experimental evidence suggests reduced catabolism plays an important role in Abeta accumulation. Although endothelin converting enzyme (ECE) and insulin degrading enzyme (IDE) degrade and thus contribute to regulating the steady-state levels of Abeta, how these enzymes are regulated remain poorly understood. In this study, we investigated the effects of 4-hydroxy-nonenal (HNE) and Abeta on the expression and activity of ECE-1 and IDE in human neuroblastoma SH-SY5Y cells. Treatment with HNE or Abeta upregulated ECE-1 mRNA and protein, while IDE was unchanged. Although both ECE-1 and IDE were oxidized within 24 h of HNE or Abeta treatment, ECE-1 catalytic activity was elevated while IDE specific activity was unchanged. The results demonstrated for the first time that both ECE-1 and IDE are substrates of HNE modification induced by Abeta. In addition, the results suggest complex mechanisms underlying the regulation of their enzymatic activity.


Assuntos
Aldeídos/farmacologia , Peptídeos beta-Amiloides/farmacologia , Ácido Aspártico Endopeptidases/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Insulisina/metabolismo , Metaloendopeptidases/metabolismo , Fragmentos de Peptídeos/farmacologia , Ácido Aspártico Endopeptidases/genética , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Enzimas Conversoras de Endotelina , Ativação Enzimática/efeitos dos fármacos , Humanos , Imunoprecipitação , Insulisina/genética , Metaloendopeptidases/genética , Neuroblastoma/enzimologia , Neuroblastoma/patologia , RNA Mensageiro/metabolismo
17.
Nat Immunol ; 10(3): 257-65, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19182807

RESUMO

The mechanisms by which cytokine signals prevent the activation and mitochondrial targeting of the proapoptotic protein Bax are unclear. Here we show, using primary human eosinophils, that in the absence of the prosurvival cytokines granulocyte-macrophage colony-stimulating factor and interleukin 5, Bax spontaneously underwent activation and initiated mitochondrial disruption. Inhibition of Bax resulted in less eosinophil apoptosis, even in the absence of cytokines. Granulocyte-macrophage colony-stimulating factor induced activation of the kinase Erk1/2, which phosphorylated Thr167 of Bax; this facilitated new interaction of Bax with the prolyl isomerase Pin1. Blockade of Pin1 led to cleavage and mitochondrial translocation of Bax and caspase activation, regardless of the presence of cytokines. Our findings indicate that Pin1 is a key mediator of prosurvival signaling and is a regulator of Bax function.


Assuntos
Eosinófilos/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Interleucina-5/imunologia , Peptidilprolil Isomerase/imunologia , Proteína X Associada a bcl-2/imunologia , Morte Celular , Sobrevivência Celular , Células Cultivadas , Eosinófilos/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/imunologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Interleucina-5/metabolismo , Mitocôndrias/imunologia , Mitocôndrias/metabolismo , Peptidilprolil Isomerase de Interação com NIMA , Peptidilprolil Isomerase/metabolismo , Fosforilação , Transporte Proteico , Proteína X Associada a bcl-2/metabolismo
18.
J Neurochem ; 108(4): 1072-82, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19196432

RESUMO

The cerebral accumulation of beta-amyloid (Abeta) is a consistent feature of and likely contributor to the development of Alzheimer's disease. In addition to dysregulated production, increasing experimental evidence suggests reduced catabolism also plays an important role in Abeta accumulation. We have previously shown that neprilysin (NEP), the major protease which cleaves Abetain vivo, is modified by 4-hydroxy-nonenal (HNE) adducts in the brain of Alzheimer's disease patients. To determine if these changes affected Abeta, SH-SY5Y cells were treated with HNE or Abeta, and then NEP mRNA, protein levels, HNE adducted NEP, NEP activity and secreted Abeta levels were determined. Intracellular NEP developed HNE adducts after 24 h of HNE treatment as determined by immunoprecipitation, immunoblotting, and double immunofluorescence staining. HNE-modified NEP showed decreased catalytic activity, which was associated with elevations in Abeta1-40 in SH-SY5Y and H4 APP695wt cells. Incubation of cells with Abeta1-42 also induced HNE adduction of NEP. In an apparent compensatory response, Abeta-treated cells showed increased NEP mRNA and protein expression. Despite elevations in NEP protein, the activity was significantly lower compared with the NEP protein level. This study demonstrates that NEP can be inactivated by HNE-adduction, which is associated with, at least partly, reduced Abeta cleavage and enhanced Abeta accumulation.


Assuntos
Aldeídos/metabolismo , Peptídeos beta-Amiloides/metabolismo , Neprilisina/metabolismo , Neurônios/metabolismo , Aldeídos/farmacologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/farmacologia , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Linhagem Celular Tumoral , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Imunofluorescência , Humanos , Immunoblotting , Imunoprecipitação , Neprilisina/efeitos dos fármacos , Neprilisina/genética , Neurônios/efeitos dos fármacos , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/farmacologia , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/fisiologia
19.
Neurobiol Aging ; 30(12): 1962-74, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18378046

RESUMO

Overproduction of amyloid precursor protein (APP) and beta-amyloid likely contribute to neurodegeneration seen in Alzheimer's disease (AD). APP mRNA contains several, 3'-untranslated region (UTR), cis-acting regulatory elements. A 52 base element (52sce), immediately downstream from the stop codon, has been previously shown to complex with uncharacterized cytoplasmic proteins. In this study, we purify and identify six proteins that specifically bind to the 52sce, and show that these proteins interact with each other and with APP mRNA in intact human neuroblastoma cells. We also present evidence that at least one of these proteins, the DEAD-box helicase rck/p54, is involved in post-transcriptional regulation, as its overexpression in cultured cells results in elevated levels of APP mRNA and protein. These findings suggest a novel mechanism for post-transcriptional regulation of APP mRNA.


Assuntos
Precursor de Proteína beta-Amiloide/metabolismo , RNA Helicases DEAD-box/metabolismo , Neurônios/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores de Superfície Celular/metabolismo , Regiões 3' não Traduzidas , Precursor de Proteína beta-Amiloide/genética , Sítios de Ligação , Linhagem Celular Tumoral , Eletroforese em Gel de Poliacrilamida , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Immunoblotting , Imuno-Histoquímica , Imunoprecipitação , Espectrometria de Massas , Microscopia Confocal , Nexinas de Proteases , Multimerização Proteica , RNA Mensageiro/metabolismo , Receptores de Superfície Celular/genética , Transfecção
20.
Blood ; 112(8): 3088-98, 2008 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-18559976

RESUMO

The purpose of this study is to correlate the presence of TP53 gene mutations with the clinical outcome of a cohort of patients with diffuse large B-cell lymphoma (DLBCL) assembled from 12 medical centers. TP53 mutations were identified in 102 of 477 patients, and the overall survival (OS) of patients with TP53 mutations was significantly worse than those with wild-type TP53 (P < .001). However, subsets of TP53 mutations were found to have different effects on OS. Mutations in the TP53 DNA-binding domains were the strongest predictors of poor OS (P < .001). Mutations in the Loop-Sheet-Helix and Loop-L3 were associated with significantly decreased OS (P = .002), but OS was not significantly affected by mutations in Loop-L2. A subset of missense mutations (His158, His175, Ser245, Gln248, His273, Arg280, and Arg282) in the DNA-binding domains had the worst prognosis. Multivariate analysis confirmed that the International Prognostic Index and mutations in the DNA-binding domains were independent predictors of OS. TP53 mutations also stratified patients with germinal center B cell-like DLBCL, but not nongerminal center B cell-like DLBCL, into molecularly distinct subsets with different survivals. This study shows the prognostic importance of mutations in the TP53 DNA-binding domains in patients with DLBCL.


Assuntos
Linfoma Difuso de Grandes Células B/genética , Mutação , Proteína Supressora de Tumor p53/genética , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ciclofosfamida/administração & dosagem , Análise Mutacional de DNA , Doxorrubicina/administração & dosagem , Éxons , Feminino , Humanos , Cooperação Internacional , Linfoma Difuso de Grandes Células B/mortalidade , Masculino , Pessoa de Meia-Idade , Prednisolona/administração & dosagem , Prognóstico , Resultado do Tratamento , Vincristina/administração & dosagem
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