RESUMO
PURPOSE: To characterize germline genetic risk factors of diabetes mellitus among long-term survivors of childhood cancer. METHODS: Adult survivors of childhood cancer from the Childhood Cancer Survivor Study (CCSS) Original Cohort (n = 5,083; 383 with diabetes) were used to conduct a discovery genome-wide association study. Replication was performed using the CCSS Expansion (n = 2,588; 40 with diabetes) and the St Jude Lifetime (SJLIFE; n = 3,351; 208 with diabetes) cohorts. Risk prediction models, stratified on exposure to abdominal radiation, were calculated using logistic regression including attained age, sex and body mass index, diagnosis, alkylating chemotherapy, age at cancer diagnosis, and a polygenic risk score (PRS) on the basis of 395 diabetes variants from the general population. Area under the receiver operating characteristic curve (AUC) was calculated for models on the basis of traditional risk factors, clinical risk factors, and PRS. RESULTS: There was a genome-wide significant association of rs55849673-A with diabetes among survivors (odds ratio, 2.9; 95% CI, 2.0 to 4.2; P = 3.7 × 10-8), which is related to expression of ERCC6L2 in the Genotype-Tissue Expression project. The association of rs55849673-A was observed largely among survivors not exposed to abdominal radiation (odds ratio = 3.5, P = 1.1 × 10-7) and the frequency of rs55849673-A was consistently higher among diabetic survivors in the CCSS Expansion and SJLIFE cohorts. Risk prediction models including traditional diabetes risk factors, clinical risk factors and PRS had an optimism-corrected AUC of 0.801, with an AUC of 0.751 in survivors treated with abdominal radiation versus 0.813 in survivors who did not receive abdominal radiation. CONCLUSION: There is evidence for a novel locus of diabetes among survivors not exposed to abdominal radiation. Further refinement and validation of clinic-based risk prediction models for diabetes among long-term survivors of childhood cancer is warranted.
Assuntos
Sobreviventes de Câncer , Diabetes Mellitus , Neoplasias , Criança , Humanos , Neoplasias/epidemiologia , Estudo de Associação Genômica Ampla , Fatores de Risco , DNA HelicasesRESUMO
The common p.D358A variant (rs2228145) in IL-6R is associated with risk for multiple diseases and with increased levels of soluble IL-6R in the periphery and central nervous system (CNS). Here, we show that the p.D358A allele leads to increased proteolysis of membrane bound IL-6R and demonstrate that IL-6R peptides with A358 are more susceptible to cleavage by ADAM10 and ADAM17. IL-6 responsive genes were identified in primary astrocytes and microglia and an IL-6 gene signature was increased in the CNS of late onset Alzheimer's disease subjects in an IL6R allele dependent manner. We conducted a screen to identify variants associated with the age of onset of Alzheimer's disease in APOE É4 carriers. Across five datasets, p.D358A had a meta Pâ=â3 ×10-4 and an odds ratioâ=â1.3, 95% confidence interval 1.12 -1.48. Our study suggests that a common coding region variant of the IL-6 receptor results in neuroinflammatory changes that may influence the age of onset of Alzheimer's disease in APOE É4 carriers.
Assuntos
Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Encéfalo/metabolismo , Polimorfismo de Nucleotídeo Único , Receptores de Interleucina-6/genética , Receptores de Interleucina-6/metabolismo , Proteína ADAM10/metabolismo , Proteína ADAM17/metabolismo , Idoso , Idoso de 80 Anos ou mais , Alelos , Animais , Apolipoproteína E4/genética , Astrócitos/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Técnicas de Cocultura , Estudos de Coortes , Feminino , Células HEK293 , Humanos , Interleucina-6/metabolismo , Masculino , Camundongos , Microglia/metabolismo , Proteínas Recombinantes/metabolismoRESUMO
BACKGROUND: Patients with sickle cell disease (SCD) may experience many complications of the central nervous system (CNS) including stroke, silent cerebral infarcts, and neuropsychological deficits. Cranial epidural hematoma is a rare but potentially serious complication. PROCEDURE: Case series of cranial epidural hematomas in children with SCD from three different institutions is considered, along with a literature review of cranial epidural hematomas in this population. RESULTS: Seven children with SCD with cranial epidural hematomas were identified from three different institutions. All patients were male and the age at presentation ranged from 10 to 18 years. Two patients presented with headache (28.6%), while the rest had no neurologic symptoms at presentation. Four patients required urgent neurosurgical intervention (57.1%) and one patient died (14.3%). A literature review identified 18 additional cases of cranial epidural hematomas in children with SCD. Of these, treatment ranged from supportive care to neurosurgical intervention. Twelve patients completely recovered (66.7%), one patient had long-term cognitive impairment (5.6%), and four patients died (22.2%). Combined with our data, cranial epidural hematomas have a mortality rate of 20.0%. CONCLUSIONS: Although rare, cranial epidural hematoma can be fatal and should be considered in patients with acute neurological symptoms.
Assuntos
Anemia Falciforme/complicações , Hematoma Epidural Craniano/etiologia , Adolescente , Adulto , Criança , Pré-Escolar , Hematoma Epidural Craniano/cirurgia , Humanos , Lactente , Recém-Nascido , Masculino , Procedimentos Neurocirúrgicos , Prognóstico , Taxa de Sobrevida , Adulto JovemRESUMO
Robo4 is an endothelial cell-specific member of the Roundabout axon guidance receptor family. To identify Robo4 binding partners, we performed a protein-protein interaction screen with the Robo4 extracellular domain. We find that Robo4 specifically binds to UNC5B, a vascular Netrin receptor, revealing unexpected interactions between two endothelial guidance receptors. We show that Robo4 maintains vessel integrity by activating UNC5B, which inhibits signaling downstream of vascular endothelial growth factor (VEGF). Function-blocking monoclonal antibodies against Robo4 and UNC5B increase angiogenesis and disrupt vessel integrity. Soluble Robo4 protein inhibits VEGF-induced vessel permeability and rescues barrier defects in Robo4(-/-) mice, but not in mice treated with anti-UNC5B. Thus, Robo4-UNC5B signaling maintains vascular integrity by counteracting VEGF signaling in endothelial cells, identifying a novel function of guidance receptor interactions in the vasculature.
Assuntos
Vasos Sanguíneos/metabolismo , Vasos Sanguíneos/patologia , Neovascularização Patológica/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Receptores de Superfície Celular/metabolismo , Receptores Imunológicos/metabolismo , Animais , Anticorpos Bloqueadores/farmacologia , Vasos Sanguíneos/efeitos dos fármacos , Vasos Sanguíneos/enzimologia , Permeabilidade Capilar/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Humanos , Ligantes , Camundongos , Modelos Biológicos , Receptores de Netrina , Ligação Proteica/efeitos dos fármacos , Vasos Retinianos/efeitos dos fármacos , Vasos Retinianos/metabolismo , Vasos Retinianos/patologia , Transdução de Sinais/efeitos dos fármacos , Sus scrofa , Fator A de Crescimento do Endotélio Vascular/metabolismo , Quinases da Família src/metabolismoRESUMO
Neuropilin-1 (NRP1) was first described as a receptor for the axon guidance molecule, Semaphorin3A, regulating the development of the nervous system. It was later shown that NRP1 is an isoform-specific receptor for vascular endothelial growth factor (VEGF), specifically VEGF(165). Much interest has been placed on the role of the various VEGF isoforms in vascular biology. Here we report that blocking NRP1 function, using a recently described antibody that inhibits VEGF(165) binding to NRP1, surprisingly reduces VEGF(121)-induced migration and sprout formation of endothelial cells. Intrigued by this observation, direct binding studies of NRP1 to various VEGF isoforms were performed. We show that VEGF(121) binds directly to NRP1; however, unlike VEGF(165), VEGF(121) is not sufficient to bridge the NRP1.VEGFR2 complex. Additionally, we show that VEGFR2 enhances VEGF(165), but not VEGF(121) binding to NRP1. We propose a new model for NRP1 interactions with various VEGF isoforms.
Assuntos
Movimento Celular , Endotélio Vascular/citologia , Neuropilina-1/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Células Endoteliais/citologia , Humanos , Neuropilina-1/fisiologia , Ligação Proteica , Isoformas de Proteínas/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/fisiologiaRESUMO
Neuropilin-1 (NRP1) guides the development of the nervous and vascular systems. Binding to either semaphorins or VEGF, NRP1 acts with plexins to regulate neuronal guidance, or with VEGFR2 to mediate vascular development. We have generated two monoclonal antibodies that bind to the Sema- and VEGF-binding domains of NRP1, respectively. Both antibodies reduce angiogenesis and vascular remodeling, while having little effect on other VEGFR2-mediated events. Importantly, anti-NRP1 antibodies have an additive effect with anti-VEGF therapy in reducing tumor growth. Vessels from tumors treated with anti-VEGF show a close association with pericytes, while tumors treated with both anti-NRP1 and anti-VEGF lack this organization. We propose that blocking NRP1 function inhibits vascular remodeling, rendering vessels more susceptible to anti-VEGF therapy.
Assuntos
Neoplasias Experimentais/irrigação sanguínea , Neovascularização Patológica/metabolismo , Neuropilina-1/imunologia , Fator A de Crescimento do Endotélio Vascular/imunologia , Animais , Anticorpos Monoclonais , Movimento Celular , Células Cultivadas , Células Endoteliais/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Camundongos , Neurônios/metabolismo , Ratos , Semaforina-3A/imunologiaRESUMO
The Drosophila nuclear factor-kappaB (NF-kappaB)-like transcription factor Relish is activated by an endoproteolytic cleavage step mediated by the Drosophila caspase Dredd. We have examined the contribution of the caspase cascade to NF-kappaB activation via TRAIL, a mammalian tumor necrosis factor family ligand that is a potent activator of caspases. Our results demonstrate that TRAIL activates NF-kappaB in two phases as follows: an early caspase independent phase and a late caspase dependent phase. The late phase of the TRAIL-induced NF-kappaB is critically dependent on caspase 8 and can be blocked by pharmacological and genetic inhibitors of caspase 8 activation, such as benzyloxycarbonyl-VAD-fluoromethyl ketone, benzyloxycarbonyl-IETD-fluoromethyl ketone, and small interfering RNA targeting caspase 8 and FADD. Whereas caspase 3 is required for TRAIL-induced apoptosis, it is not involved in TRAIL-induced NF-kappaB activation. The late phase of TRAIL-induced NF-kappaB activation involves caspase mediated cleavage of IkappaBalpha between Asp(31) and Ser(32) residues to generate an N-terminal truncated fragment that is degraded by the proteasome via the N-end rule pathway. Our results demonstrate that caspases play an evolutionarily conserved role as regulated entry points to the N-end rule pathway and in NF-kappaB activation in mammalian cells.
Assuntos
Caspases/metabolismo , Evolução Molecular , Proteínas I-kappa B/metabolismo , NF-kappa B/metabolismo , Clorometilcetonas de Aminoácidos/farmacologia , Apoptose/fisiologia , Caspase 3 , Caspase 6 , Caspase 7 , Caspase 8 , Inibidores de Caspase , Inibidores de Cisteína Proteinase/farmacologia , Células HeLa , Humanos , Inibidor de NF-kappaB alfa , Receptores do Fator de Necrose Tumoral/metabolismoRESUMO
In mammals, members of the tumor necrosis factor (TNF) family play an important role in the regulation of cellular proliferation, differentiation and programmed cell death. We describe isolation and characterization of an orthologous ligand/receptor axis in Drosophila. The ligand, designated Eiger, is a type II membrane glycosylated protein, which can be cleaved at residue 145 and released from the cell surface as a soluble factor, thereby representing the first potential cytokine to be described in Drosophila. Eiger exists in two alternatively spliced isoforms, Eiger long (Eiger-L) and Eiger short (Eiger-s), both of which are expressed throughout development and in the adult. We also describe the isolation and characterization of a novel Drosophila member of the TNF receptor family, designated Wengen, which is a type I membrane protein that can physically interact with the recently described TRAF2 homolog dTRAF2. Both Eiger and Wengen are expressed in distinctive patterns during embryogenesis and Eiger is responsive to genotoxic stress. Forced expression of Eiger-L, Eiger-s or Wengen, caused apoptotic cell death which could be rescued by caspase inhibitors or the JNK phosphatase Puckered. In addition, Eiger-induced cell killing was attenuated by RNAi-mediated suppression of Wengen. Our results illustrate that Eiger and Wengen represent proximal components of an evolutionarily conserved TNF-like signaling pathway in Drosophila.
Assuntos
Proteínas de Drosophila/fisiologia , Drosophila melanogaster/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno , Proteínas de Membrana/fisiologia , Receptores do Fator de Necrose Tumoral/fisiologia , Sequência de Aminoácidos , Animais , Apoptose , Dano ao DNA , DNA Complementar/genética , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Drosophila melanogaster/embriologia , Drosophila melanogaster/genética , Embrião não Mamífero/metabolismo , Evolução Molecular , Regulação da Expressão Gênica no Desenvolvimento , Inativação Gênica/efeitos dos fármacos , Glicosilação , MAP Quinase Quinase 4 , Proteínas de Membrana/química , Proteínas de Membrana/genética , Quinases de Proteína Quinase Ativadas por Mitógeno/fisiologia , Dados de Sequência Molecular , Fosfoproteínas Fosfatases/genética , Fosfoproteínas Fosfatases/fisiologia , Processamento de Proteína Pós-Traducional , Proteínas/metabolismo , RNA Antissenso/fisiologia , RNA de Cadeia Dupla/farmacologia , RNA Interferente Pequeno , Receptores do Fator de Necrose Tumoral/genética , Proteínas Recombinantes de Fusão/fisiologia , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Especificidade da Espécie , Fator 2 Associado a Receptor de TNF , Transfecção , Fator de Necrose Tumoral alfa/químicaRESUMO
The human herpesvirus 8 (HHV8, also called Kaposi's sarcoma-associated herpesvirus) has been linked to Kaposi's sarcoma and primary effusion lymphoma (PEL) in immunocompromised individuals. We demonstrate that PEL cell lines have a constitutively active NF-kappaB pathway, which is associated with persistent phosphorylation of IkappaBalpha. To elucidate the mechanism of NF-kappaB activation in PEL cell lines, we have investigated the role of viral FLICE inhibitory protein (vFLIP) in this process. We report that stable expression of HHV8 vFLIP in a variety of cell lines is associated with persistent NF-kappaB activation caused by constitutive phosphorylation of IkappaBalpha. HHV8 vFLIP gets recruited to a approximately 700-kDa IkappaB kinase (IKK) complex and physically associates with IKKalpha, IKKbeta, NEMO/IKKgamma, and RIP. HHV8 vFLIP is incapable of activating NF-kappaB in cells deficient in NEMO/IKKgamma, thereby suggesting an essential role of an intact IKK complex in this process. Our results suggest that HHV8 vFLIP might contribute to the persistent NF-kappaB activation observed in PEL cells by associating with and stimulating the activity of the cellular IKK complex.