Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Parasit Vectors ; 17(1): 259, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38879603

RESUMO

BACKGROUND: Powassan virus, a North American tick-borne flavivirus, can cause severe neuroinvasive disease in humans. While Ixodes scapularis are the primary vectors of Powassan virus lineage II (POWV II), also known as deer tick virus, recent laboratory vector competence studies showed that other genera of ticks can horizontally and vertically transmit POWV II. One such tick is the Haemaphysalis longicornis, an invasive species from East Asia that recently established populations in the eastern USA and already shares overlapping geographic range with native vector species such as I. scapularis. Reports of invasive H. longicornis feeding concurrently with native I. scapularis on multiple sampled hosts highlight the potential for interspecies co-feeding transmission of POWV II. Given the absence of a clearly defined vertebrate reservoir host for POWV II, it is possible that this virus is sustained in transmission foci via nonviremic transmission between ticks co-feeding on the same vertebrate host. The objective of this study was to evaluate whether uninfected H. longicornis co-feeding in close proximity to POWV II-infected I. scapularis can acquire POWV independent of host viremia. METHODS: Using an in vivo tick transmission model, I. scapularis females infected with POWV II ("donors") were co-fed on mice with uninfected H. longicornis larvae and nymphs ("recipients"). The donor and recipient ticks were infested on mice in various sequences, and mouse infection status was monitored by temporal screening of blood for POWV II RNA via quantitative reverse transcription polymerase chain reaction (q-RT-PCR). RESULTS: The prevalence of POWV II RNA was highest in recipient H. longicornis that fed on viremic mice. However, nonviremic mice were also able to support co-feeding transmission of POWV, as demonstrated by the detection of viral RNA in multiple H. longicornis dispersed across different mice. Detection of viral RNA at the skin site of tick feeding but not at distal skin sites indicates that a localized skin infection facilitates transmission of POWV between donor and recipient ticks co-feeding in close proximity. CONCLUSIONS: This is the first report examining transmission of POWV between co-feeding ticks. Against the backdrop of multiple unknowns related to POWV ecology, findings from this study provide insight on possible mechanisms by which POWV could be maintained in nature.


Assuntos
Vírus da Encefalite Transmitidos por Carrapatos , Encefalite Transmitida por Carrapatos , Ixodes , Ixodidae , Animais , Vírus da Encefalite Transmitidos por Carrapatos/genética , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Vírus da Encefalite Transmitidos por Carrapatos/fisiologia , Encefalite Transmitida por Carrapatos/transmissão , Encefalite Transmitida por Carrapatos/virologia , Ixodes/virologia , Ixodes/fisiologia , Camundongos , Ixodidae/virologia , Ixodidae/fisiologia , Feminino , Comportamento Alimentar , Espécies Introduzidas , Haemaphysalis longicornis , População do Leste Asiático
2.
Life Sci Alliance ; 5(2)2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34810279

RESUMO

Metastasis is the leading driver of cancer-related death. Tumor cell plasticity associated with the epithelial-mesenchymal transition (EMT), an embryonic program also observed in carcinomas, has been proposed to explain the colonization of distant organs by the primary tumor cells. Many studies have established correlations between EMT marker expression in the primary tumor and metastasis in vivo. However, the longstanding model of EMT-transitioned cells disseminating to secondary sites is still actively debated and hybrid states are presently considered as more relevant during tumor progression and metastasis. Here, we describe an unexplored role of EMT on the tumor microenvironment by controlling tumor innervation. Using in vitro and in vivo breast tumor progression models, we demonstrate that TGFß-mediated tumor cell EMT triggers the expression of the embryonic LincRNA Platr18 those elevated expression controls the expression of the axon guidance protein semaphorin-4F and other neuron-related molecules such as IGSF11/VSIG-3. Platr18/Sema4F axis silencing abrogates axonogenesis and attenuates metastasis. Our observations suggest that EMT-transitioned cells are also locally required in the primary tumor to support distant dissemination by promoting axonogenesis, a biological process known for its role in metastatic progression of breast cancer.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Regulação Neoplásica da Expressão Gênica , RNA Longo não Codificante/genética , Fator de Crescimento Transformador beta/metabolismo , Microambiente Tumoral , Neoplasias da Mama/patologia , Transição Epitelial-Mesenquimal , Feminino , Humanos , Microambiente Tumoral/genética
4.
Nat Cell Biol ; 19(9): 1105-1115, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28825698

RESUMO

The contribution of lncRNAs to tumour progression and the regulatory mechanisms driving their expression are areas of intense investigation. Here, we characterize the binding of heterogeneous nuclear ribonucleoprotein E1 (hnRNP E1) to a nucleic acid structural element located in exon 12 of PNUTS (also known as PPP1R10) pre-RNA that regulates its alternative splicing. HnRNP E1 release from this structural element, following its silencing, nucleocytoplasmic translocation or in response to TGFß, allows alternative splicing and generates a non-coding isoform of PNUTS. Functionally the lncRNA-PNUTS serves as a competitive sponge for miR-205 during epithelial-mesenchymal transition (EMT). In mesenchymal breast tumour cells and in breast tumour samples, the expression of lncRNA-PNUTS is elevated and correlates with levels of ZEB mRNAs. Thus, PNUTS is a bifunctional RNA encoding both PNUTS mRNA and lncRNA-PNUTS, each eliciting distinct biological functions. While PNUTS mRNA is ubiquitously expressed, lncRNA-PNUTS appears to be tightly regulated dependent on the status of hnRNP E1 and tumour context.


Assuntos
Processamento Alternativo , Neoplasias da Mama/metabolismo , Proteínas de Ligação a DNA/metabolismo , Transição Epitelial-Mesenquimal , Neoplasias Pulmonares/metabolismo , Proteínas Nucleares/metabolismo , Precursores de RNA/metabolismo , RNA Longo não Codificante/metabolismo , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo , Células A549 , Animais , Sítios de Ligação , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Células CACO-2 , Movimento Celular , Proteínas de Ligação a DNA/genética , Éxons , Feminino , Regulação Neoplásica da Expressão Gênica , Ribonucleoproteínas Nucleares Heterogêneas/genética , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/secundário , Células MCF-7 , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Invasividade Neoplásica , Proteínas Nucleares/genética , Conformação de Ácido Nucleico , Ligação Proteica , Interferência de RNA , Precursores de RNA/química , Precursores de RNA/genética , Sítios de Splice de RNA , RNA Longo não Codificante/química , RNA Longo não Codificante/genética , RNA Mensageiro/química , RNA Mensageiro/genética , Proteínas de Ligação a RNA/genética , Transdução de Sinais , Relação Estrutura-Atividade , Transcrição Gênica , Transfecção , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...