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1.
J Neurosci ; 42(25): 5085-5101, 2022 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-35589390

RESUMO

Endosomal sorting plays a fundamental role in directing neural development. By altering the temporal and spatial distribution of membrane receptors, endosomes regulate signaling pathways that control the differentiation and function of neural cells. Several genes linked to inherited demyelinating peripheral neuropathies, known as Charcot-Marie-Tooth (CMT) disease, encode proteins that directly interact with components of the endosomal sorting complex required for transport (ESCRT). Our previous studies demonstrated that a point mutation in the ESCRT component hepatocyte growth-factor-regulated tyrosine kinase substrate (HGS), an endosomal scaffolding protein that identifies internalized cargo to be sorted by the endosome, causes a peripheral neuropathy in the neurodevelopmentally impaired teetering mice. Here, we constructed a Schwann cell-specific deletion of Hgs to determine the role of endosomal sorting during myelination. Inactivation of HGS in Schwann cells resulted in motor and sensory deficits, slowed nerve conduction velocities, delayed myelination and hypomyelinated axons, all of which occur in demyelinating forms of CMT. Consistent with a delay in Schwann cell maturation, HGS-deficient sciatic nerves displayed increased mRNA levels for several promyelinating genes and decreased mRNA levels for genes that serve as markers of myelinating Schwann cells. Loss of HGS also altered the abundance and activation of the ERBB2/3 receptors, which are essential for Schwann cell development. We therefore hypothesize that HGS plays a critical role in endosomal sorting of the ERBB2/3 receptors during Schwann cell maturation, which further implicates endosomal dysfunction in inherited peripheral neuropathies.SIGNIFICANCE STATEMENT Schwann cells myelinate peripheral axons, and defects in Schwann cell function cause inherited demyelinating peripheral neuropathies known as CMT. Although many CMT-linked mutations are in genes that encode putative endosomal proteins, little is known about the requirements of endosomal sorting during myelination. In this study, we demonstrate that loss of HGS disrupts the endosomal sorting pathway in Schwann cells, resulting in hypomyelination, aberrant myelin sheaths, and impairment of the ERBB2/3 receptor pathway. These findings suggest that defective endosomal trafficking of internalized cell surface receptors may be a common mechanism contributing to demyelinating CMT.


Assuntos
Doença de Charcot-Marie-Tooth , Animais , Doença de Charcot-Marie-Tooth/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte , Endossomos/metabolismo , Camundongos , Doenças do Sistema Nervoso Periférico , RNA Mensageiro , Células de Schwann/metabolismo
2.
J Org Chem ; 88(4): 2589-2598, 2023 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-36706424

RESUMO

We demonstrate a general method for the preparation of diverse N-substituted 3,4-dihydroisoquinolin-1(2H)-one compounds through an overall three-step cross-coupling/cyclization/N-deprotection/N-alkylation sequence. In the first step, ethyl 2-bromobenzoates and 2-bromo-1-carboxyethyl heterocycles are cross-coupled with commercially available potassium (2-((tert-butoxycarbonyl)amino)ethyl)trifluoroborate to produce (hetero)aryl-substituted 3-[(N-Boc-2-carboxyethyl)phenyl]ethylamines. In a subsequent two-stage process, these (hetero)arylethylamines undergo base-mediated ring closure followed by N-deprotection and N-alkylation to produce N-substituted 3,4-dihydroisoquinolin-1(2H)-ones and heteroaryl-fused N-benzyl 3,4-dihydropyridin-2(1H)-ones. Mechanistic work was performed to elucidate the order of transformations for the latter two-stage process. The method was also extended to the production of N-benzyl isoindolin-1-one and N-benzyl 2,3,4,5-tetrahydro-1H-benzo[c]azepin-1-one.

3.
Anim Biotechnol ; 34(4): 775-784, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32707002

RESUMO

Development of simple and readily adoptable methods to mediate germline engineering of the chicken genome will have many applications in research, agriculture and industrial biotechnology. We report germline targeting of the endogenous chicken Interferon Alpha and Beta Receptor Subunit 1 (IFNAR1) gene by in vivo transgenic expression of the high-fidelity Cas9 (Cas9-HF1) and guide RNAs (gRNAs) in chickens. First, we developed a Tol2 transposon vector carrying Cas9-HF1, IFNAR1-gRNAs (IF-gRNAs) and green fluorescent protein (GFP) transgenes (pTgRCG) and validated in chicken fibroblast DF1 cells. Next, the pTgRCG plasmid was directly injected into the dorsal aorta of embryonic day (ED) 2.5 chicken embryos targeting the circulating primordial germ cells (PGCs). The resulting chimera roosters generated a fully transgenic generation 1 (G1) hen with constitutive expression of Cas9-HF1 and IF-gRNAs (G1_Tol2-Cas9/IF-gRNA). We detected a spectrum of indels at gRNA-targeted loci in the G1_Tol2-Cas9/IF-gRNA hen and the indels were stably inherited by the G2 progeny. Breeding of the G1_Tol2-Cas9/IF-gRNA hen resulted in up to 10% transgene-free heterozygote IFNAR1 mutants, following null-segregation of the Tol2 insert. The method described here will provide new opportunities for genome editing in chicken and other avian species that lack PGC culture.


Assuntos
Sistemas CRISPR-Cas , Galinhas , Animais , Embrião de Galinha , Feminino , Masculino , Galinhas/genética , Sistemas CRISPR-Cas/genética , Transfecção , Animais Geneticamente Modificados/genética , Edição de Genes/métodos , Células Germinativas/metabolismo
4.
J Virol ; 95(14): e0011121, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-33952646

RESUMO

The current fears of a future influenza pandemic have resulted in an increased emphasis on the development and testing of novel therapeutic strategies against the virus. Fundamental to this is the ferret model of influenza infection, which is critical in examining pathogenesis and treatment. Nevertheless, a precise evaluation of the efficacy of any treatment strategy in ferrets is reliant on understanding the immune response in this model. Interferon-inducible transmembrane proteins (IFITMs) are interferon-stimulated proteins shown to be critically important in the host immune response against viral infections. These proteins confer intrinsic innate immunity to pH-dependent viruses such as influenza viruses and can inhibit cytosolic entry of such viruses to limit the severity of infection following interferon upregulation. Mutations in IFITM genes in humans have been identified as key risk factors for worsened disease progression, particularly in the case of avian influenza viruses such as H7N9. While the IFITM genes of humans and mice have been well characterized, no studies have been conducted to classify the IFITM locus and interferon-driven upregulation of IFITMs in ferrets. Here, we show the architecture of the ferret IFITM locus and its synteny to the IFITM locus of other mammalian and avian species. Furthermore, we show that ferret IFITM1, -2, and -3 are functionally responsive to both interferon-α (IFN-α) and influenza virus stimulation. Thus, we show that ferret IFITMs exhibit interferon-stimulated properties similar to those shown in other species, furthering our knowledge of the innate immune response in the ferret model of human influenza virus infections. IMPORTANCE IFITM proteins can prevent the entry of several pH-dependent viruses, including high-consequence viruses such as HIV, influenza viruses, and SARS-coronaviruses. Mutations in these genes have been associated with worsened disease outcomes with mutations in their IFITM genes, highlighting these genes as potential disease risk factors. Ferrets provide a valuable tool to model infectious diseases; however, there is a critical shortage of information regarding their interferon-stimulated genes. We identified the putative ferret IFITM genes and mapped their complete gene locus. Thus, our study fills a critical gap in knowledge and supports the further use of the ferret model to explore the importance of IFITMs in these important diseases.


Assuntos
Furões , Vírus da Influenza A Subtipo H1N1 , Interferon-alfa/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Infecções por Orthomyxoviridae/imunologia , Animais , Linhagem Celular , Sequência Conservada , Modelos Animais de Doenças , Furões/imunologia , Furões/metabolismo , Furões/virologia , Humanos , Modelos Moleculares , Infecções por Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/metabolismo , Reação em Cadeia da Polimerase , Análise de Sequência de Proteína , Regulação para Cima
5.
J Virol ; 95(15): e0032721, 2021 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-33963054

RESUMO

The human protein-coding gene ILRUN (inflammation and lipid regulator with UBA-like and NBR1-like domains; previously C6orf106) was identified as a proviral factor for Hendra virus infection and was recently characterized to function as an inhibitor of type I interferon expression. Here, we have utilized transcriptome sequencing (RNA-seq) to define cellular pathways regulated by ILRUN in the context of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of Caco-2 cells. We find that inhibition of ILRUN expression by RNA interference alters transcription profiles of numerous cellular pathways, including upregulation of the SARS-CoV-2 entry receptor ACE2 and several other members of the renin-angiotensin aldosterone system. In addition, transcripts of the SARS-CoV-2 coreceptors TMPRSS2 and CTSL were also upregulated. Inhibition of ILRUN also resulted in increased SARS-CoV-2 replication, while overexpression of ILRUN had the opposite effect, identifying ILRUN as a novel antiviral factor for SARS-CoV-2 replication. This represents, to our knowledge, the first report of ILRUN as a regulator of the renin-angiotensin-aldosterone system (RAAS). IMPORTANCE There is no doubt that the current rapid global spread of COVID-19 has had significant and far-reaching impacts on our health and economy and will continue to do so. Research in emerging infectious diseases, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is growing rapidly, with new breakthroughs in the understanding of host-virus interactions to assist with the development of innovative and exciting therapeutic strategies. Here, we present the first evidence that modulation of the human protein-coding gene ILRUN functions as an antiviral factor for SARS-CoV-2 infection, likely through its newly identified role in regulating the expression of SARS-CoV-2 entry receptors ACE2, TMPRSS2, and CTSL. These data improve our understanding of biological pathways that regulate host factors critical to SARS-CoV-2 infection, contributing to the development of antiviral strategies to deal with the current SARS-CoV-2 pandemic.


Assuntos
Enzima de Conversão de Angiotensina 2/biossíntese , COVID-19/metabolismo , Regulação para Baixo , Regulação Enzimológica da Expressão Gênica , Proteínas de Neoplasias/metabolismo , SARS-CoV-2/metabolismo , Enzima de Conversão de Angiotensina 2/genética , Animais , COVID-19/genética , Células CACO-2 , Catepsina L/biossíntese , Catepsina L/genética , Chlorocebus aethiops , Humanos , Proteínas de Neoplasias/genética , Sistema Renina-Angiotensina , SARS-CoV-2/genética , Serina Endopeptidases/biossíntese , Serina Endopeptidases/genética , Células Vero
6.
PLoS Biol ; 17(11): e3000558, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31693658

RESUMO

[This corrects the article DOI: 10.1371/journal.pbio.1002580.].

7.
J Biol Chem ; 295(8): 2348-2358, 2020 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-31959629

RESUMO

The oncogenic receptor tyrosine kinase AXL is overexpressed in cancer and plays an important role in carcinomas of multiple organs. However, the mechanisms of AXL overexpression in cancer remain unclear. In this study, using HEK293T, Panc-1, and Panc-28 cells and samples of human pancreatic intraepithelial neoplasia (PanIN), along with several biochemical approaches and immunofluorescence microscopy analyses, we sought to investigate the mechanisms that regulate AXL over-expression in pancreatic ductal adenocarcinoma (PDAC). We found that AXL interacts with hematopoietic progenitor kinase 1 (HPK1) and demonstrate that HPK1 down-regulates AXL and decreases its half-life. The HPK1-mediated AXL degradation was inhibited by the endocytic pathway inhibitors leupeptin, bafilomycin A1, and monensin. HPK1 accelerated the movement of AXL from the plasma membrane to endosomes in pancreatic cancer cells treated with the AXL ligand growth arrest-specific 6 (GAS6). Moreover, HPK1 increased the binding of AXL to the Cbl proto-oncogene (c-Cbl); promoted AXL ubiquitination; decreased AXL-mediated signaling, including phospho-AKT and phospho-ERK signaling; and decreased the invasion capability of PDAC cells. Importantly, we show that AXL expression inversely correlates with HPK1 expression in human PanINs and that patients whose tumors have low HPK1 and high AXL expression levels have shorter survival than those with low AXL or high HPK1 expression (p < 0.001). Our results suggest that HPK1 is a tumor suppressor that targets AXL for degradation via the endocytic pathway. HPK1 loss of function may contribute to AXL overexpression and thereby enhance AXL-dependent downstream signaling and tumor invasion in PDAC.


Assuntos
Regulação para Baixo , Oncogenes , Neoplasias Pancreáticas/enzimologia , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Carcinoma in Situ/enzimologia , Carcinoma in Situ/patologia , Linhagem Celular Tumoral , Citoplasma/metabolismo , Endocitose , Endossomos/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Estimativa de Kaplan-Meier , Sistema de Sinalização das MAP Quinases , Invasividade Neoplásica , Neoplasias Pancreáticas/patologia , Ligação Proteica , Transporte Proteico , Proteólise , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-cbl/metabolismo , Ubiquitinação , Receptor Tirosina Quinase Axl
8.
Mol Cell Neurosci ; 108: 103542, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32841720

RESUMO

The extracellular accumulation of amyloid ß (Aß) fragments of amyloid precursor protein (APP) in brain parenchyma is a pathological hallmark of Alzheimer's disease (AD). APP can be cleaved into Aß on late endosomes/multivesicular bodies (MVBs). E3 ubiquitin ligases have been linked to Aß production, but specific E3 ligases associated with APP ubiquitination that may affect targeting of APP to endosomes have not yet been described. Using cultured cortical neurons isolated from rat pups, we reconstituted APP movement into the internal vesicles (ILVs) of MVBs. Loss of endosomal sorting complexes required for transport (ESCRT) components inhibited APP movement into ILVs and increased endosomal Aß42 generation, implying a requirement for APP ubiquitination. We identified an ESCRT-binding and APP-interacting endosomal E3 ubiquitin ligase, ubiquitination factor E4B (UBE4B) that regulates APP ubiquitination. Depleting UBE4B in neurons inhibited APP ubiquitination and internalization into MVBs, resulting in increased endosomal Aß42 levels and increased neuronal secretion of Aß42. When we examined AD brains, we found levels of the UBE4B-interacting ESCRT component, hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs), were significantly decreased in AD brains. These data suggest that ESCRT components critical for membrane protein sorting in the endocytic pathway are altered in AD. These results indicate that the molecular machinery underlying endosomal trafficking of APP, including the ubiquitin ligase UBE4B, regulates Aß levels and may play an essential role in AD progression.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Endossomos/metabolismo , Neurônios/metabolismo , Fragmentos de Peptídeos/metabolismo , Ubiquitinação , Animais , Células Cultivadas , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Feminino , Células HEK293 , Humanos , Masculino , Transporte Proteico , Ratos , Vesículas Secretórias/metabolismo
9.
Int J Mol Sci ; 22(7)2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33806254

RESUMO

The global COVID-19 pandemic caused by SARS-CoV-2 has resulted in over 2.2 million deaths. Disease outcomes range from asymptomatic to severe with, so far, minimal genotypic change to the virus so understanding the host response is paramount. Transcriptomics has become incredibly important in understanding host-pathogen interactions; however, post-transcriptional regulation plays an important role in infection and immunity through translation and mRNA stability, allowing tight control over potent host responses by both the host and the invading virus. Here, we apply ribosome profiling to assess post-transcriptional regulation of host genes during SARS-CoV-2 infection of a human lung epithelial cell line (Calu-3). We have identified numerous transcription factors (JUN, ZBTB20, ATF3, HIVEP2 and EGR1) as well as select antiviral cytokine genes, namely IFNB1, IFNL1,2 and 3, IL-6 and CCL5, that are restricted at the post-transcriptional level by SARS-CoV-2 infection and discuss the impact this would have on the host response to infection. This early phase restriction of antiviral transcripts in the lungs may allow high viral load and consequent immune dysregulation typically seen in SARS-CoV-2 infection.


Assuntos
Citocinas/genética , Processamento Pós-Transcricional do RNA , Ribossomos/metabolismo , Ribossomos/virologia , SARS-CoV-2/imunologia , Fatores de Transcrição/genética , Animais , Antivirais/antagonistas & inibidores , Linhagem Celular Tumoral , Chlorocebus aethiops , Biologia Computacional , Citocinas/metabolismo , Células Epiteliais/imunologia , Células Epiteliais/virologia , Perfilação da Expressão Gênica , Interações entre Hospedeiro e Microrganismos , Humanos , Imunidade Inata/genética , Pulmão/imunologia , Pulmão/virologia , RNA Mensageiro/metabolismo , RNA-Seq , Ribossomos/genética , SARS-CoV-2/metabolismo , Fatores de Transcrição/metabolismo , Transcriptoma , Células Vero
10.
J Neuroophthalmol ; 40(3): 414-416, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32804458

RESUMO

Neurocysticercosis is the most common disease of the nervous system caused by a parasite. Ophthalmological manifestations of cysticercosis typically are due to direct intraorbital or intraocular involvement, parenchymal brainstem involvement, or secondary to hydrocephalus or increased intracranial pressure. We describe a patient with a unilateral fourth nerve palsy, a rare presentation of neurocyticercosis.


Assuntos
Encéfalo/diagnóstico por imagem , Neurocisticercose/complicações , Doenças do Nervo Troclear/etiologia , Adulto , Biópsia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Neurocisticercose/diagnóstico , Doenças do Nervo Troclear/diagnóstico
11.
J Biol Chem ; 293(27): 10561-10573, 2018 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-29802199

RESUMO

Host recognition of intracellular viral RNA and subsequent induction of cytokine signaling are tightly regulated at the cellular level and are a target for manipulation by viruses and therapeutics alike. Here, we characterize chromosome 6 ORF 106 (C6orf106) as an evolutionarily conserved inhibitor of the innate antiviral response. C6orf106 suppresses the synthesis of interferon (IFN)-α/ß and proinflammatory tumor necrosis factor (TNF) α in response to the dsRNA mimic poly(I:C) and to Sendai virus infection. Unlike canonical inhibitors of antiviral signaling, C6orf106 blocks interferon-regulatory factor 3 (IRF3) and, to a lesser extent, NF-κB activity without modulating their activation, nuclear translocation, cellular expression, or degradation. Instead, C6orf106 interacts with IRF3 and inhibits IRF3 recruitment to type I IFN promoter sequences while also reducing the nuclear levels of the coactivator proteins p300 and CREB-binding protein (CBP). In summary, we have defined C6orf106 as a negative regulator of antiviral immunity that blocks IRF3-dependent cytokine production via a noncanonical and poorly defined mechanism. This work presents intriguing implications for antiviral immunity, autoimmune disorders, and cancer.


Assuntos
Antivirais/farmacologia , Imunidade Inata/imunologia , Fator Regulador 3 de Interferon/antagonistas & inibidores , Proteínas de Neoplasias/farmacologia , Infecções por Respirovirus/prevenção & controle , Vírus Sendai/imunologia , Animais , Antivirais/administração & dosagem , Chlorocebus aethiops , Regulação da Expressão Gênica , Células HeLa , Humanos , Imunidade Inata/efeitos dos fármacos , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/metabolismo , NF-kappa B/antagonistas & inibidores , NF-kappa B/genética , NF-kappa B/metabolismo , Proteínas de Neoplasias/administração & dosagem , Infecções por Respirovirus/imunologia , Infecções por Respirovirus/virologia , Vírus Sendai/efeitos dos fármacos , Transdução de Sinais , Células Vero
12.
Curr Top Microbiol Immunol ; 419: 191-213, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28674944

RESUMO

Hendra and Nipah viruses (family Paramyxoviridae, genus Henipavirus) are zoonotic RNA viruses that cause lethal disease in humans and are designated as Biosafety Level 4 (BSL4) agents. Moreover, henipaviruses belong to the same group of viruses that cause disease more commonly in humans such as measles, mumps and respiratory syncytial virus. Due to the relatively recent emergence of the henipaviruses and the practical constraints of performing functional genomics studies at high levels of containment, our understanding of the henipavirus infection cycle is incomplete. In this chapter we describe recent loss-of-function (i.e. RNAi) functional genomics screens that shed light on the henipavirus-host interface at a genome-wide level. Further to this, we cross-reference RNAi results with studies probing host proteins targeted by henipavirus proteins, such as nuclear proteins and immune modulators. These functional genomics studies join a growing body of evidence demonstrating that nuclear and nucleolar host proteins play a crucial role in henipavirus infection. Furthermore these studies will underpin future efforts to define the role of nucleolar host-virus interactions in infection and disease.


Assuntos
Genômica , Vírus Hendra/imunologia , Infecções por Henipavirus/genética , Infecções por Henipavirus/imunologia , Interações Hospedeiro-Patógeno , MicroRNAs/metabolismo , Vírus Nipah/imunologia , Proteínas Nucleares/metabolismo , Infecções por Henipavirus/metabolismo , Infecções por Henipavirus/virologia , Humanos , MicroRNAs/genética , Proteínas Nucleares/genética
13.
PLoS Biol ; 14(11): e1002580, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27855162

RESUMO

The extracellular matrix (ECM) provides physical scaffolding for cellular constituents and initiates biochemical and biomechanical cues that are required for physiological activity of living tissues. The ECM enzyme ADAMTS5, a member of the ADAMTS (A Disintegrin-like and Metalloproteinase with Thrombospondin-1 motifs) protein family, cleaves large proteoglycans such as aggrecan, leading to the destruction of cartilage and osteoarthritis. However, its contribution to viral pathogenesis and immunity is currently undefined. Here, we use a combination of in vitro and in vivo models to show that ADAMTS5 enzymatic activity plays a key role in the development of influenza-specific immunity. Influenza virus infection of Adamts5-/- mice resulted in delayed virus clearance, compromised T cell migration and immunity and accumulation of versican, an ADAMTS5 proteoglycan substrate. Our research emphasises the importance of ADAMTS5 expression in the control of influenza virus infection and highlights the potential for development of ADAMTS5-based therapeutic strategies to reduce morbidity and mortality.


Assuntos
Proteína ADAMTS5/fisiologia , Imunidade Celular/fisiologia , Orthomyxoviridae/imunologia , Linfócitos T/imunologia , Proteína ADAMTS5/genética , Animais , Imunofenotipagem , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Versicanas/metabolismo , Redução de Peso
14.
Exp Cell Res ; 372(1): 1-15, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30144444

RESUMO

Regulating the residence time of membrane proteins on the cell surface can modify their response to extracellular cues and allow for cellular adaptation in response to changing environmental conditions. The fate of membrane proteins that are internalized from the plasma membrane and arrive at the limiting membrane of the late endosome/multivesicular body (MVB) is dictated by whether they remain on the limiting membrane, bud into internal MVB vesicles, or bud outwardly from the membrane. The molecular details underlying the disposition of membrane proteins that transit this pathway and the mechanisms regulating these trafficking events are unclear. We established a cell-free system that reconstitutes budding of membrane protein cargo into internal MVB vesicles and onto vesicles that bud outwardly from the MVB membrane. Both budding reactions are cytosol-dependent and supported by Saccharomyces cerevisiae (yeast) cytosol. We observed that inward and outward budding from the MVB membrane are mechanistically distinct but may be linked, such that inhibition of inward budding triggers a re-routing of cargo from inward to outward budding vesicles, without affecting the number of vesicles that bud outwardly from MVBs.


Assuntos
Membrana Celular/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Membranas Intracelulares/metabolismo , Lisossomos/metabolismo , Corpos Multivesiculares/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Membrana Celular/química , Sistema Livre de Células/química , Sistema Livre de Células/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/ultraestrutura , Regulação da Expressão Gênica , Células HeLa , Humanos , Membranas Intracelulares/ultraestrutura , Lisossomos/ultraestrutura , Corpos Multivesiculares/ultraestrutura , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Transporte Proteico , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo , Transdução de Sinais
15.
BMC Med Inform Decis Mak ; 19(1): 125, 2019 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-31272427

RESUMO

BACKGROUND: Coordination of care, especially after a patient experiences an acute care event, is a challenge for many health systems. Event notification is a form of health information exchange (HIE) which has the potential to support care coordination by alerting primary care providers when a patient experiences an acute care event. While promising, there exists little evidence on the impact of event notification in support of reengagement into primary care. The objectives of this study are to 1) examine the effectiveness of event notification on health outcomes for older adults who experience acute care events, and 2) compare approaches to how providers respond to event notifications. METHODS: In a cluster randomized trial conducted across two medical centers within the U.S. Veterans Health Administration (VHA) system, we plan to enroll older patients (≥ 65 years of age) who utilize both VHA and non-VHA providers. Patients will be enrolled into one of three arms: 1) usual care; 2) event notifications only; or 3) event notifications plus a care transitions intervention. In the event notification arms, following a non-VHA acute care encounter, an HIE-based intervention will send an event notification to VHA providers. Patients in the event notification plus care transitions arm will also receive 30 days of care transition support from a social worker. The primary outcome measure is 90-day readmission rate. Secondary outcomes will be high risk medication discrepancies as well as care transitions processes within the VHA health system. Qualitative assessments of the intervention will inform VHA system-wide implementation. DISCUSSION: While HIE has been evaluated in other contexts, little evidence exists on HIE-enabled event notification interventions. Furthermore, this trial offers the opportunity to examine the use of event notifications that trigger a care transitions intervention to further support coordination of care. TRIAL REGISTRATION: ClinicalTrials.gov NCT02689076. "Regional Data Exchange to Improve Care for Veterans After Non-VA Hospitalization." Registered 23 February 2016.


Assuntos
Serviço Hospitalar de Emergência , Troca de Informação em Saúde , Sistemas de Informação Hospitalar , Hospitalização , Veteranos , Humanos , Estados Unidos , United States Department of Veterans Affairs
16.
Gerontol Geriatr Educ ; 40(1): 3-15, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-29583103

RESUMO

The Rural Interdisciplinary Team Training Program (RITT) is a team-based educational component of the Veterans Health Administration (VHA) Office of Rural Health Geriatric Scholars Program. It is a workforce development program to enhance the geriatrics knowledge and skills of VA primary care clinicians and staff caring for older veterans in rural communities. The RITT workshop, accredited for 6.5 hours, is interactive and multi-modal with didactic mini-lectures, interactive case discussions and role play demonstrations of assessments. Clinic teams also develop and implement a small quality improvement project based on common challenges faced by older persons. This report is an evaluation of the effect of the RITT Program on geriatrics knowledge and team development as well as success in developing and implementing the quality improvement projects in 80 VHA rural outpatient clinics in 38 states.


Assuntos
Geriatria/educação , Pessoal de Saúde/educação , Equipe de Assistência ao Paciente/organização & administração , Serviços de Saúde Rural/organização & administração , Desenvolvimento de Pessoal/organização & administração , Instrução por Computador , Processos Grupais , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Equipe de Assistência ao Paciente/normas , Avaliação de Programas e Projetos de Saúde , Melhoria de Qualidade/organização & administração , Serviços de Saúde Rural/normas , Estados Unidos , United States Department of Veterans Affairs/organização & administração
17.
J Infect Dis ; 217(4): 548-559, 2018 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-29325138

RESUMO

Background: Two influenza B virus lineages, B/Victoria and B/Yamagata, cocirculate in the human population. While the lineages are serologically distinct, cross-reactive responses to both lineages have been detected. Viral interference describes the situation whereby infection with one virus limits infection and replication of a second virus. We investigated the potential for viral interference between the influenza B virus lineages. Methods: Ferrets were infected and then challenged 3, 10, or 28 days later with pairs of influenza B/Victoria and B/Yamagata viruses. Results: Viral interference occurred at challenge intervals of 3 and 10 days and occasionally at 28 days. At the longer interval, shedding of challenge virus was reduced, and this correlated with cross-reactive interferon γ responses from lymph nodes from virus-infected animals. Viruses from both lineages could prevent or significantly limit subsequent infection with a virus from the other lineage. Coinfections were rare, indicating the potential for reassortment between lineages is limited. Conclusions: These data suggest that innate and cross-reactive immunity mediate viral interference and that this may contribute to the dominance of a specific influenza B virus lineage in any given influenza season. Furthermore, infection with one influenza B virus lineage may be beneficial in protecting against subsequent infection with either influenza B virus lineage.


Assuntos
Proteção Cruzada , Vírus da Influenza B/imunologia , Vírus da Influenza B/fisiologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Interferência Viral , Animais , Reações Cruzadas , Modelos Animais de Doenças , Furões , Imunidade Inata
18.
PLoS Pathog ; 12(3): e1005478, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27010548

RESUMO

Hendra and Nipah viruses (genus Henipavirus, family Paramyxoviridae) are highly pathogenic bat-borne viruses. The need for high biocontainment when studying henipaviruses has hindered the development of therapeutics and knowledge of the viral infection cycle. We have performed a genome-wide siRNA screen at biosafety level 4 that identified 585 human proteins required for henipavirus infection. The host protein with the largest impact was fibrillarin, a nucleolar methyltransferase that was also required by measles, mumps and respiratory syncytial viruses for infection. While not required for cell entry, henipavirus RNA and protein syntheses were greatly impaired in cells lacking fibrillarin, indicating a crucial role in the RNA replication phase of infection. During infection, the Hendra virus matrix protein co-localized with fibrillarin in cell nucleoli, and co-associated as a complex in pulldown studies, while its nuclear import was unaffected in fibrillarin-depleted cells. Mutagenesis studies showed that the methyltransferase activity of fibrillarin was required for henipavirus infection, suggesting that this enzyme could be targeted therapeutically to combat henipavirus infections.


Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Infecções por Henipavirus/virologia , Vírus Nipah/enzimologia , Animais , Chlorocebus aethiops , Proteínas Cromossômicas não Histona/genética , Células HeLa , Vírus Hendra/metabolismo , Humanos , Mutação , Vírus Nipah/genética , Vírus Nipah/patogenicidade , RNA Interferente Pequeno , Células Vero , Proteínas da Matriz Viral/metabolismo
19.
PLoS Pathog ; 12(10): e1005974, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27783670

RESUMO

Hendra and Nipah viruses (family Paramyxoviridae, genus Henipavirus) are bat-borne viruses that cause fatal disease in humans and a range of other mammalian species. Gaining a deeper understanding of host pathways exploited by henipaviruses for infection may identify targets for new anti-viral therapies. Here we have performed genome-wide high-throughput agonist and antagonist screens at biosafety level 4 to identify host-encoded microRNAs (miRNAs) impacting henipavirus infection in human cells. Members of the miR-181 and miR-17~93 families strongly promoted Hendra virus infection. miR-181 also promoted Nipah virus infection, but did not affect infection by paramyxoviruses from other genera, indicating specificity in the virus-host interaction. Infection promotion was primarily mediated via the ability of miR-181 to significantly enhance henipavirus-induced membrane fusion. Cell signalling receptors of ephrins, namely EphA5 and EphA7, were identified as novel negative regulators of henipavirus fusion. The expression of these receptors, as well as EphB4, were suppressed by miR-181 overexpression, suggesting that simultaneous inhibition of several Ephs by the miRNA contributes to enhanced infection and fusion. Immune-responsive miR-181 levels was also up-regulated in the biofluids of ferrets and horses infected with Hendra virus, suggesting that the host innate immune response may promote henipavirus spread and exacerbate disease severity. This study is the first genome-wide screen of miRNAs influencing infection by a clinically significant mononegavirus and nominates select miRNAs as targets for future anti-viral therapy development.


Assuntos
Infecções por Henipavirus/genética , MicroRNAs/genética , Internalização do Vírus , Animais , Furões , Imunofluorescência , Estudo de Associação Genômica Ampla , Henipavirus , Sequenciamento de Nucleotídeos em Larga Escala , Cavalos , Humanos , Reação em Cadeia da Polimerase em Tempo Real
20.
J Genet Couns ; 2018 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-30121717

RESUMO

Genetic counseling is a rapidly expanding field, and the supply of certified genetic counselors is currently unable to keep up with job demand. Research is fairly limited regarding the awareness and perceptions that prospective genetic counseling students have on the field and what factors most influence their interest. The current study includes data collected from 1389 undergraduate students in the sciences at 23 universities across the United States who were surveyed regarding information related to their awareness, perceptions, knowledge, and interest in genetic counseling. The majority of participants had heard of genetic counseling (78.0%), many from a high school course (37.3%), college course (28.1%), or online (11.5%). Familiarity was associated with factors such as female gender (p = 0.003) and length of time in school (p < 0.001). After taking the survey, participant interest was positively associated with several factors including female gender (p < 0.001) and Asian and Hispanic ethnicity (p = 0.012). Factors commonly reported as attractive about the field included direct patient care, the variety of roles available, cultural competency and psychosocial training, and helping others. Discussion elaborates upon specific factors related to student awareness and interest in genetic counseling and potential ways to tailor recruitment strategies for maximum benefit to the field.

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