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1.
PLoS Pathog ; 20(2): e1012007, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38386661

RESUMO

Smallpox was the most rampant infectious disease killer of the 20th century, yet much remains unknown about the pathogenesis of the variola virus. Using archived tissue from a study conducted at the Centers for Disease Control and Prevention we characterized pathology in 18 cynomolgus macaques intravenously infected with the Harper strain of variola virus. Six macaques were placebo-treated controls, six were tecovirimat-treated beginning at 2 days post-infection, and six were tecovirimat-treated beginning at 4 days post-infection. All macaques were treated daily until day 17. Archived tissues were interrogated using immunohistochemistry, in situ hybridization, immunofluorescence, and electron microscopy. Gross lesions in three placebo-treated animals that succumbed to infection primarily consisted of cutaneous vesicles, pustules, or crusts with lymphadenopathy. The only gross lesions noted at the conclusion of the study in the three surviving placebo-treated and the Day 4 treated animals consisted of resolving cutaneous pox lesions. No gross lesions attributable to poxviral infection were present in the Day 2 treated macaques. Histologic lesions in three placebo-treated macaques that succumbed to infection consisted of proliferative and necrotizing dermatitis with intracytoplasmic inclusion bodies and lymphoid depletion. The only notable histologic lesion in the Day 4 treated macaques was resolving dermatitis; no notable lesions were seen in the Day 2 treated macaques. Variola virus was detected in all three placebo-treated animals that succumbed to infection prior to the study's conclusion by all utilized methods (IHC, ISH, IFA, EM). None of the three placebo-treated animals that survived to the end of the study nor the animals in the two tecovirimat treatment groups showed evidence of variola virus by these methods. Our findings further characterize variola lesions in the macaque model and describe new molecular methods for variola detection.


Assuntos
Dermatite , Varíola , Vírus da Varíola , Animais , Benzamidas , Isoindóis , Macaca fascicularis , Varíola/tratamento farmacológico , Varíola/patologia , Estados Unidos
2.
Can J Neurol Sci ; 51(1): 78-86, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36715071

RESUMO

BACKGROUND & AIMS: It is unknown if the COVID-19 pandemic and public health measures had an immediate impact on stroke subtypes and etiologies in patients not infected with COVID-19. We aimed to evaluate if the proportion of non-COVID-19-related stroke subtypes (ischemic vs. hemorrhagic) and etiologies (cardioembolic, atherosclerosis, small vessel disease, and others) during the pandemic's first wave were different from prepandemic. METHODS: For this retrospective cohort study, we included patients without COVID-19 with ischemic or hemorrhagic stroke at two large Canadian stroke centers between March-May 2019 (prepandemic cohort) and March-May 2020 (pandemic cohort). Proportions of stroke subtypes and etiologies were compared between cohorts using chi-square tests. RESULTS: The prepandemic cohort consisted of 234 stroke patients and the pandemic cohort of 207 stroke patients. There were no major differences in baseline characteristics. The proportions of ischemic versus hemorrhagic stroke were similar (ischemic stroke: 77% prepandemic vs. 75% pandemic; hemorrhagic stroke:12% prepandemic vs. 14% pandemic; p > 0.05). There were no differences in etiologies, except for a decreased proportion of ischemic stroke due to atherosclerosis in the pandemic cohort (26% prepandemic vs. 15% pandemic; difference: 10.6%, 95%CI: 1.4-19.7; p = 0.03). Notably, during the pandemic, the cause of ischemic stroke was more often unknown because of incomplete work-up (13.3% prepandemic vs. 28.2% pandemic, difference: 14.9%, 95%-CI: 5.7-24.2; p = <0.01). CONCLUSIONS: In this study, the pandemic had no clear effect on stroke subtypes and etiologies suggesting a limited impact of the pandemic on stroke triggers. However, the shift from atherosclerosis toward other causes warrants further exploration.


Assuntos
Aterosclerose , COVID-19 , Acidente Vascular Cerebral Hemorrágico , AVC Isquêmico , Acidente Vascular Cerebral , Humanos , COVID-19/epidemiologia , Pandemias , Estudos Retrospectivos , Canadá/epidemiologia , Acidente Vascular Cerebral/epidemiologia
3.
J Christ Nurs ; 40(3): 184-190, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36787474

RESUMO

ABSTRACT: One out of five Medicare beneficiaries is readmitted within 30 days after hospital discharge, and as many as three in four readmissions are preventable. This study describes transitional care interventions (TCIs) delivered by one faith community nurse (FCN) to at-risk seniors living in a certain ZIP code. Two years of nursing documentation (2,280 interventions) were translated into Nursing Interventions Classification standardized nursing language. Results indicate the FCN provided priority TCIs including spiritual care. In fully describing TCIs using a nursing language, results support that the FCN transitional care model is a method worth exploring to provide wholistic transitional care.


Assuntos
Enfermagem Paroquial , Terminologia Padronizada em Enfermagem , Cuidado Transicional , Idoso , Humanos , Estados Unidos , Medicare , Alta do Paciente
4.
Microbiology (Reading) ; 168(3)2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35293855

RESUMO

Type IV pili are involved in adhesion, twitching motility, aggregation, biofilm formation and virulence in a variety of Gram-negative bacteria. Burkholderia pseudomallei, the causative agent of melioidosis and a Tier 1 biological select agent, is a Gram-negative bacterium with eight type IV pili-associated loci (TFP1 to TFP8). Most have not been fully characterized. In this study, we investigated BPSS2185, an uncharacterized TFP8 gene that encodes a type IVB pilus protein subunit. Using genetic deletion and complementation analysis in B. pseudomallei JW270, we demonstrate that BPSS2185 plays an important role in twitching motility and adhesion to A549 human alveolar epithelial cells. Compared to JW270, the JW270 ΔBPSS2185 mutant failed to display twitching motility and did not adhere to the epithelial cells. These phenotypes were partially reversed by the complementation of BPSS2185 in the mutant strain. The study also shows that BPSS2185 is expressed only during the onset of mature biofilm formation and at the dispersal of a biofilm, suggesting that the motility characteristic is required to form a biofilm. Our study is the first to suggest that the BPSS2185 gene in TFP8 contributes to twitching motility, adhesion and biofilm formation, indicating that the gene may contribute to B. pseudomallei virulence.


Assuntos
Burkholderia pseudomallei , Proteínas de Fímbrias , Biofilmes , Burkholderia pseudomallei/genética , Burkholderia pseudomallei/metabolismo , Células Epiteliais/metabolismo , Proteínas de Fímbrias/genética , Proteínas de Fímbrias/metabolismo , Fímbrias Bacterianas/genética , Fímbrias Bacterianas/metabolismo
5.
J Infect Dis ; 224(4): 632-642, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-33367826

RESUMO

BACKGROUND: Ebola virus disease (EVD) supportive care strategies are largely guided by retrospective observational research. This study investigated the effect of EVD supportive care algorithms on duration of survival in a controlled nonhuman primate (NHP) model. METHODS: Fourteen rhesus macaques were challenged intramuscularly with a target dose of Ebola virus (1000 plaque-forming units; Kikwit). NHPs were allocated to intensive care unit (ICU)-like algorithms (n = 7), intravenous fluids plus levofloxacin (n = 2), or a control group (n = 5). The primary outcome measure was duration of survival, and secondary outcomes included changes in clinical laboratory values. RESULTS: Duration of survival was not significantly different between the pooled ICU-like algorithm and control groups (8.2 vs 6.9 days of survival; hazard ratio; 0.50; P = .25). Norepinephrine was effective in transiently maintaining baseline blood pressure. NHPs treated with ICU-like algorithms had delayed onset of liver and kidney injury. CONCLUSIONS: While an obvious survival difference was not observed with ICU-like care, clinical observations from this model may aid in EVD supportive care NHP model refinement.


Assuntos
Cuidados Críticos , Doença pelo Vírus Ebola , Unidades de Terapia Intensiva , Animais , Modelos Animais de Doenças , Ebolavirus , Doença pelo Vírus Ebola/terapia , Macaca mulatta , Primatas , Estudos Retrospectivos
6.
Gastroenterology ; 158(8): 2236-2249.e9, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32112796

RESUMO

BACKGROUND & AIMS: Microvillus inclusion disease (MVID) is caused by inactivating mutations in the myosin VB gene (MYO5B). MVID is a complex disorder characterized by chronic, watery, life-threatening diarrhea that usually begins in the first hours to days of life. We developed a large animal model of MVID to better understand its pathophysiology. METHODS: Pigs were cloned by transfer of chromatin from swine primary fetal fibroblasts, which were edited with TALENs and single-strand oligonucleotide to introduce a P663-L663 substitution in the endogenous swine MYO5B (corresponding to the P660L mutation in human MYO5B, associated with MVID) to fertilized oocytes. We analyzed duodenal tissues from patients with MVID (with the MYO5B P660L mutation) and without (controls), and from pigs using immunohistochemistry. Enteroids were generated from pigs with MYO5B(P663L) and without the substitution (control pigs). RESULTS: Duodenal tissues from patients with MVID lacked MYO5B at the base of the apical membrane of intestinal cells; instead MYO5B was intracellular. Intestinal tissues and derived enteroids from MYO5B(P663L) piglets had reduced apical levels and diffuse subapical levels of sodium hydrogen exchanger 3 and SGLT1, which regulate transport of sodium, glucose, and water, compared with tissues from control piglets. However, intestinal tissues and derived enteroids from MYO5B(P663L) piglets maintained CFTR on apical membranes, like tissues from control pigs. Liver tissues from MYO5B(P663L) piglets had alterations in bile salt export pump, a transporter that facilitates bile flow, which is normally expressed in the bile canaliculi in the liver. CONCLUSIONS: We developed a large animal model of MVID that has many features of the human disease. Studies of this model could provide information about the functions of MYO5B and MVID pathogenesis, and might lead to new treatments.


Assuntos
Duodeno/metabolismo , Edição de Genes , Mucosa Intestinal/metabolismo , Síndromes de Malabsorção/genética , Microvilosidades/patologia , Mucolipidoses/genética , Cadeias Pesadas de Miosina/genética , Miosina Tipo V/genética , Transportador 1 de Glucose-Sódio/metabolismo , Trocador 3 de Sódio-Hidrogênio/metabolismo , Animais , Animais Geneticamente Modificados , Células Cultivadas , Técnicas de Cocultura , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Modelos Animais de Doenças , Duodeno/patologia , Predisposição Genética para Doença , Humanos , Mucosa Intestinal/patologia , Síndromes de Malabsorção/metabolismo , Síndromes de Malabsorção/patologia , Microvilosidades/genética , Microvilosidades/metabolismo , Mucolipidoses/metabolismo , Mucolipidoses/patologia , Mutação de Sentido Incorreto , Fenótipo , Sódio/metabolismo , Transportador 1 de Glucose-Sódio/genética , Trocador 3 de Sódio-Hidrogênio/genética , Sus scrofa
7.
J Virol ; 94(22)2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-32900822

RESUMO

Animal models recapitulating human COVID-19 disease, especially severe disease, are urgently needed to understand pathogenesis and to evaluate candidate vaccines and therapeutics. Here, we develop novel severe-disease animal models for COVID-19 involving disruption of adaptive immunity in Syrian hamsters. Cyclophosphamide (CyP) immunosuppressed or RAG2 knockout (KO) hamsters were exposed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by the respiratory route. Both the CyP-treated and RAG2 KO hamsters developed clinical signs of disease that were more severe than those in immunocompetent hamsters, notably weight loss, viral loads, and fatality (RAG2 KO only). Disease was prolonged in transiently immunosuppressed hamsters and was uniformly lethal in RAG2 KO hamsters. We evaluated the protective efficacy of a neutralizing monoclonal antibody and found that pretreatment, even in immunosuppressed animals, limited infection. Our results suggest that functional B and/or T cells are not only important for the clearance of SARS-CoV-2 but also play an early role in protection from acute disease.IMPORTANCE Syrian hamsters are in use as a model of disease caused by SARS-CoV-2. Pathology is pronounced in the upper and lower respiratory tract, and disease signs and endpoints include weight loss and viral RNA and/or infectious virus in swabs and organs (e.g., lungs). However, a high dose of virus is needed to produce disease, and the disease resolves rapidly. Here, we demonstrate that immunosuppressed hamsters are susceptible to low doses of virus and develop more severe and prolonged disease. We demonstrate the efficacy of a novel neutralizing monoclonal antibody using the cyclophosphamide transient suppression model. Furthermore, we demonstrate that RAG2 knockout hamsters develop severe/fatal disease when exposed to SARS-CoV-2. These immunosuppressed hamster models provide researchers with new tools for evaluating therapies and vaccines and understanding COVID-19 pathogenesis.


Assuntos
Infecções por Coronavirus/imunologia , Infecções por Coronavirus/patologia , Modelos Animais de Doenças , Mesocricetus , Pneumonia Viral/imunologia , Pneumonia Viral/patologia , Imunidade Adaptativa , Animais , Animais Geneticamente Modificados , Betacoronavirus/fisiologia , COVID-19 , Ciclofosfamida , Proteínas de Ligação a DNA/genética , Técnicas de Inativação de Genes , Imunossupressores , Pandemias , SARS-CoV-2 , Índice de Gravidade de Doença
8.
Traffic ; 19(11): 879-892, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30095213

RESUMO

Deficiency in diacylglycerol acyltransferase (DGAT1) is a rare cause of neonatal diarrhea, without a known mechanism or in vitro model. A patient presenting at our institution at 7 weeks of life with failure to thrive and diarrhea was found by whole-exome sequencing to have a homozygous DGAT1 truncation mutation. Duodenal biopsies showed loss of DGAT1 and deficits in apical membrane transporters and junctional proteins in enterocytes. When placed on a very low-fat diet, the patient's diarrhea resolved with normalization of brush border transporter localization in endoscopic biopsies. DGAT1 knockdown in Caco2-BBe cells modeled the deficits in apical trafficking, with loss of apical DPPIV and junctional occludin. Elevation in cellular lipid levels, including diacylglycerol (DAG) and phospholipid metabolites of DAG, was documented by lipid analysis in DGAT1 knockdown cells. Culture of the DGAT1 knockdown cells in lipid-depleted media led to re-establishment of occludin and return of apical DPPIV. DGAT1 loss appears to elicit global changes in enterocyte polarized trafficking that could account for deficits in absorption seen in the patient. The in vitro modeling of this disease should allow for investigation of possible therapeutic targets.


Assuntos
Diacilglicerol O-Aciltransferase/genética , Diarreia Infantil/genética , Doenças do Sistema Digestório/genética , Células CACO-2 , Pré-Escolar , Diacilglicerol O-Aciltransferase/deficiência , Diacilglicerol O-Aciltransferase/metabolismo , Diarreia Infantil/patologia , Doenças do Sistema Digestório/patologia , Humanos , Lactente , Absorção Intestinal , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Transporte Proteico
9.
J Intellect Disabil ; 24(2): 177-193, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30003830

RESUMO

There is an appropriate increasing focus on the need to ensure the voices of people with intellectual disability are captured as part of assessing individuals' quality of life; however, there remains a lack of a consensus on ways to achieve this. This article describes the development of a self-report measure of quality of life for people with intellectual disability, the 'Mini-MANS-LD', based on the concepts of Maslow's hierarchy of needs. Following use with 33 individuals with intellectual disability, the Mini-MANS-LD was found to have acceptable psychometric properties, including moderate congruent validity and acceptable internal consistency. Administrators' feedback suggested good acceptability and feasibility, and the measure was relatively quick to administer, easy to use and acceptable to service users. Despite a small sample size, this initial study suggests that the Mini-MANS-LD may present a conceptually relevant, feasible and acceptable self-report measure of quality of life for people with intellectual disability.


Assuntos
Deficiência Intelectual/psicologia , Pessoas com Deficiência Mental/psicologia , Psicometria/normas , Qualidade de Vida/psicologia , Autorrelato/normas , Adulto , Feminino , Humanos , Masculino , Psicometria/instrumentação , Reprodutibilidade dos Testes
10.
Microb Pathog ; 137: 103742, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31513897

RESUMO

Low molecular mass penicillin binding proteins (LMM PBP) are bacterial enzymes involved in the final steps of peptidoglycan biosynthesis. In Escherichia coli, most LMM PBP exhibit dd-carboxypeptidase activity, are not essential for growth in routine laboratory media, and contributions to virulent phenotypes remain largely unknown. The Francisella tularensis Schu S4 genome harbors the dacD gene (FTT_1029), which encodes a LMM PBP with homology to PBP6b of E. coli. Disruption of this locus in the fully virulent Schu S4 strain resulted in a mutant that could not grow in Chamberlain's Defined Medium and exhibited severe morphological defects. Further characterization studies demonstrated that the growth defects of the dacD mutant were pH-dependent, and could be partially restored by growth at neutral pH or fully restored by genetic complementation. Infection of murine macrophage-like cells showed that the Schu S4 dacD mutant is capable of intracellular replication. However, this mutant was attenuated in BALB/c mice following intranasal challenge (LD50 = 603 CFU) as compared to mice challenged with the parent (LD50 = 1 CFU) or complemented strain (LD50 = 1 CFU). Additionally, mice that survived infection with the dacD mutant showed significant protection against subsequent challenge with the parent strain. Collectively, these results indicate that the DacD protein of F. tularensis is essential for growth in low pH environments and virulence in vivo. These results also suggest that a PBP mutant could serve as the basis of a novel, live attenuated vaccine strain.


Assuntos
Francisella tularensis/enzimologia , Francisella tularensis/patogenicidade , D-Ala-D-Ala Carboxipeptidase Tipo Serina/metabolismo , Tularemia/imunologia , Animais , Proteínas de Bactérias/genética , Vacinas Bacterianas/imunologia , Linhagem Celular , Modelos Animais de Doenças , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Francisella tularensis/genética , Pulmão/microbiologia , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Mutação , Proteínas de Ligação às Penicilinas , D-Ala-D-Ala Carboxipeptidase Tipo Serina/genética , Tularemia/microbiologia , Vacinas Atenuadas/imunologia , Virulência , Fatores de Virulência/genética
11.
Am J Respir Cell Mol Biol ; 59(2): 158-166, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29625013

RESUMO

Alveolar type II (AT2) epithelial cells are uniquely specialized to produce surfactant in the lung and act as progenitor cells in the process of repair after lung injury. AT2 cell injury has been implicated in several lung diseases, including idiopathic pulmonary fibrosis and bronchopulmonary dysplasia. The inability to maintain primary AT2 cells in culture has been a significant barrier in the investigation of pulmonary biology. We have addressed this knowledge gap by developing a three-dimensional (3D) organotypic coculture using primary human fetal AT2 cells and pulmonary fibroblasts. Grown on top of matrix-embedded fibroblasts, the primary human AT2 cells establish a monolayer and have direct contact with the underlying pulmonary fibroblasts. Unlike conventional two-dimensional (2D) culture, the structural and functional phenotype of the AT2 cells in our 3D organotypic culture was preserved over 7 days of culture, as evidenced by the presence of lamellar bodies and by production of surfactant proteins B and C. Importantly, the AT2 cells in 3D cocultures maintained the ability to replicate, with approximately 60% of AT2 cells staining positive for the proliferation marker Ki67, whereas no such proliferation is evident in 2D cultures of the same primary AT2 cells. This organotypic culture system enables interrogation of AT2 epithelial biology by providing a reductionist in vitro model in which to investigate the response of AT2 epithelial cells and AT2 cell-fibroblast interactions during lung injury and repair.


Assuntos
Comunicação Celular/fisiologia , Células Epiteliais/metabolismo , Lesão Pulmonar/patologia , Pulmão/patologia , Células Cultivadas , Técnicas de Cocultura , Fibroblastos/metabolismo , Humanos , Fenótipo
12.
J Biol Chem ; 292(50): 20394-20409, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29054927

RESUMO

Microtubules in animal cells assemble (nucleate) from both the centrosome and the cis-Golgi cisternae. A-kinase anchor protein 350 kDa (AKAP350A, also called AKAP450/CG-NAP/AKAP9) is a large scaffolding protein located at both the centrosome and Golgi apparatus. Previous findings have suggested that AKAP350 is important for microtubule dynamics at both locations, but how this scaffolding protein assembles microtubule nucleation machinery is unclear. Here, we found that overexpression of the C-terminal third of AKAP350A, enhanced GFP-AKAP350A(2691-3907), induces the formation of multiple microtubule-nucleation centers (MTNCs). Nevertheless, these induced MTNCs lacked "true" centriole proteins, such as Cep135. Mapping analysis with AKAP350A truncations demonstrated that AKAP350A contains discrete regions responsible for promoting or inhibiting the formation of multiple MTNCs. Moreover, GFP-AKAP350A(2691-3907) recruited several pericentriolar proteins to MTNCs, including γ-tubulin, pericentrin, Cep68, Cep170, and Cdk5RAP2. Proteomic analysis indicated that Cdk5RAP2 and Cep170 both interact with the microtubule nucleation-promoting region of AKAP350A, whereas Cep68 interacts with the distal C-terminal AKAP350A region. Yeast two-hybrid assays established a direct interaction of Cep170 with AKAP350A. Super-resolution and deconvolution microscopy analyses were performed to define the association of AKAP350A with centrosomes, and these studies disclosed that AKAP350A spans the bridge between centrioles, co-localizing with rootletin and Cep68 in the linker region. siRNA-mediated depletion of AKAP350A caused displacement of both Cep68 and Cep170 from the centrosome. These results suggest that AKAP350A acts as a scaffold for factors involved in microtubule nucleation at the centrosome and coordinates the assembly of protein complexes associating with the intercentriolar bridge.


Assuntos
Proteínas de Ancoragem à Quinase A/metabolismo , Centrossomo/metabolismo , Proteínas do Citoesqueleto/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Centro Organizador dos Microtúbulos/metabolismo , Modelos Moleculares , Proteínas do Tecido Nervoso/metabolismo , Fosfoproteínas/metabolismo , Proteínas de Ancoragem à Quinase A/antagonistas & inibidores , Proteínas de Ancoragem à Quinase A/química , Proteínas de Ancoragem à Quinase A/genética , Biomarcadores/metabolismo , Proteínas de Ciclo Celular , Linhagem Celular , Centrossomo/ultraestrutura , Proteínas do Citoesqueleto/antagonistas & inibidores , Proteínas do Citoesqueleto/química , Proteínas do Citoesqueleto/genética , Humanos , Imageamento Tridimensional , Peptídeos e Proteínas de Sinalização Intracelular/química , Peptídeos e Proteínas de Sinalização Intracelular/genética , Proteínas Luminescentes/química , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Microscopia Eletrônica de Transmissão , Proteínas Associadas aos Microtúbulos/química , Proteínas Associadas aos Microtúbulos/genética , Centro Organizador dos Microtúbulos/ultraestrutura , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Fosfoproteínas/química , Fosfoproteínas/genética , Domínios e Motivos de Interação entre Proteínas , Mapeamento de Interação de Proteínas , Multimerização Proteica , Proteômica/métodos , Interferência de RNA , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Técnicas do Sistema de Duplo-Híbrido
13.
J Cell Sci ; 128(18): 3444-55, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26272915

RESUMO

Directed delivery of EGF receptor (EGFR) ligands to the apical or basolateral surface is a crucial regulatory step in the initiation of EGFR signaling in polarized epithelial cells. Herein, we show that the EGFR ligand betacellulin (BTC) is preferentially sorted to the basolateral surface of polarized MDCK cells. By using sequential truncations and site-directed mutagenesis within the BTC cytoplasmic domain, combined with selective cell-surface biotinylation and immunofluorescence, we have uncovered a monoleucine-based basolateral-sorting motif (EExxxL, specifically (156)EEMETL(161)). Disruption of this sorting motif led to equivalent apical and basolateral localization of BTC. Unlike other EGFR ligands, BTC mistrafficking induced formation of lateral lumens in polarized MDCK cells, and this process was significantly attenuated by inhibition of EGFR. Additionally, expression of a cancer-associated somatic BTC mutation (E156K) led to BTC mistrafficking and induced lateral lumens in MDCK cells. Overexpression of BTC, especially mistrafficking forms, increased the growth of MDCK cells. These results uncover a unique role for BTC mistrafficking in promoting epithelial reorganization.


Assuntos
Betacelulina , Polaridade Celular , Sequência de Aminoácidos , Animais , Betacelulina/genética , Betacelulina/metabolismo , Cães , Família de Proteínas EGF , Receptores ErbB/genética , Receptores ErbB/metabolismo , Imunofluorescência , Células Madin Darby de Rim Canino , Mutação , Sinais Direcionadores de Proteínas/genética , Estrutura Terciária de Proteína
14.
J Cell Sci ; 128(8): 1617-26, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25673875

RESUMO

Rab11a is a key component of the apical recycling endosome that aids in the trafficking of proteins to the luminal surface in polarized epithelial cells. Utilizing conditional Rab11a-knockout specific to intestinal epithelial cells, and human colonic epithelial CaCo2-BBE cells with stable Rab11a knockdown, we examined the molecular and pathological impact of Rab11a deficiency on the establishment of apical cell polarity and microvillus morphogenesis. We demonstrate that loss of Rab11a induced alterations in enterocyte polarity, shortened microvillar length and affected the formation of microvilli along the lateral membranes. Rab11a deficiency in enterocytes altered the apical localization of syntaxin 3. These data affirm the role of Rab11a in apical membrane trafficking and the maintenance of apical microvilli in enterocytes.


Assuntos
Enterócitos/ultraestrutura , Microvilosidades/metabolismo , Proteínas Qa-SNARE/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Animais , Células CACO-2 , Polaridade Celular , Endossomos/metabolismo , Células HEK293 , Humanos , Camundongos , Camundongos Knockout , Transporte Proteico
15.
Am J Pathol ; 185(8): 2219-31, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26073039

RESUMO

Doublecortin-like kinase 1 (Dclk1) is considered a reliable marker for tuft cells in the gastrointestinal tract. We investigated the dynamic changes of tuft cells associated with mouse models of oxyntic atrophy and metaplasia in the stomach. Increases in the numbers of Dclk1-positive tuft cells were observed in several models of parietal cell loss. However, the expanded population of Dclk1-expressing cells showed a morphologically distinct structure in apical microvilli and acetylated microtubules, which was not seen in the tuft cells present in the normal gastric mucosa. These microvillar sensory cells (MVSCs) showed no evidence of proliferation. The expansion of the MVSCs induced by oxyntic atrophy was reversible after the return of parietal cells. More important, expansion of MVSCs after induced parietal cell loss was not observed in Gast(-/-) mice. Although the Dclk1-expressing cells in the normal gastric mucosa were in part derived from Lrig1-expressing stem cells, the Lrig1-lineaged cells did not produce the expanded Dclk1-expressing cells associated with oxyntic atrophy. These studies indicate that loss of parietal cells leads to the reversible emergence of a novel Dclk1-expressing sensory cell population in the gastric mucosa.


Assuntos
Mucosa Gástrica/metabolismo , Gastrinas/metabolismo , Células Parietais Gástricas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Atrofia/metabolismo , Atrofia/patologia , Quinases Semelhantes a Duplacortina , Mucosa Gástrica/patologia , Metaplasia , Camundongos , Células Parietais Gástricas/patologia , Proteínas Serina-Treonina Quinases/genética , Estômago/patologia
16.
PLoS Pathog ; 9(4): e1003278, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23592992

RESUMO

The incorporation of the envelope glycoprotein complex (Env) onto the developing particle is a crucial step in the HIV-1 lifecycle. The long cytoplasmic tail (CT) of Env is required for the incorporation of Env onto HIV particles in T cells and macrophages. Here we identify the Rab11a-FIP1C/RCP protein as an essential cofactor for HIV-1 Env incorporation onto particles in relevant human cells. Depletion of FIP1C reduced Env incorporation in a cytoplasmic tail-dependent manner, and was rescued by replenishment of FIP1C. FIP1C was redistributed out of the endosomal recycling complex to the plasma membrane by wild type Env protein but not by CT-truncated Env. Rab14 was required for HIV-1 Env incorporation, and FIP1C mutants incapable of binding Rab14 failed to rescue Env incorporation. Expression of FIP1C and Rab14 led to an enhancement of Env incorporation, indicating that these trafficking factors are normally limiting for CT-dependent Env incorporation onto particles. These findings support a model for HIV-1 Env incorporation in which specific targeting to the particle assembly microdomain on the plasma membrane is mediated by FIP1C and Rab14.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , HIV-1/metabolismo , Proteínas de Membrana/metabolismo , Montagem de Vírus , Internalização do Vírus , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Membrana Celular/virologia , Células Cultivadas , Infecções por HIV/metabolismo , Células HeLa , Humanos , Proteínas de Membrana/genética , Transporte Proteico , Interferência de RNA , Replicação Viral , Proteínas rab de Ligação ao GTP/genética
17.
J Immunol ; 190(10): 5086-101, 2013 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-23596309

RESUMO

Autophagy plays a critical role in multiple aspects of the immune system, including the development and function of T lymphocytes. In mammalian cells, the class III PI3K vacuolar protein sorting (Vps)34 is thought to play a critical role in autophagy. However, recent studies have cast doubt on the role of Vps34 in autophagy, at least in certain cell types. To study the effects of Vps34 on autophagy in T lymphocytes, we generated mice that selectively lack Vps34 in the T cell lineage. Vps34 ablation in T cells caused profound defects in autophagic flux, resulting in accumulation of cellular organelles and apoptosis. These animals exhibited normal intrathymic development of conventional T cells, but they were profoundly impaired in the intrathymic development of invariant NKT cells. In peripheral organs, T cell-specific ablation of Vps34 had a profound impact on T cell homeostasis and function. Furthermore, aged animals developed an inflammatory wasting syndrome characterized by weight loss, intestinal inflammation, and anemia. Consistent with this phenotype, Vps34 was required for the peripheral maintenance and function of CD4(+)Foxp3(+) regulatory T cells. Collectively, our study reveals a critical role for Vps34 in autophagy and for the peripheral homeostasis and function of T lymphocytes.


Assuntos
Autofagia/genética , Classe III de Fosfatidilinositol 3-Quinases/genética , Linfócitos T Reguladores/imunologia , Síndrome de Emaciação/genética , Síndrome de Emaciação/imunologia , Transferência Adotiva , Envelhecimento , Animais , Apoptose/genética , Colite/imunologia , Fatores de Transcrição Forkhead/metabolismo , Inflamação , Interleucina-2/biossíntese , Camundongos , Camundongos Knockout , Células T Matadoras Naturais/imunologia , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/metabolismo
18.
Am J Physiol Cell Physiol ; 307(8): C684-98, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25122876

RESUMO

Genesis of myofibroblasts is obligatory for the development of pathology in many adult lung diseases. Adult lung tissue contains a population of perivascular ABCG2(pos) mesenchymal stem cells (MSC) that are precursors of myofibroblasts and distinct from NG2 pericytes. We hypothesized that these MSC participate in deleterious remodeling associated with pulmonary fibrosis (PF) and associated hypertension (PH). To test this hypothesis, resident lung MSC were quantified in lung samples from control subjects and PF patients. ABCG2(pos) cell numbers were decreased in human PF and interstitial lung disease compared with control samples. Genetic labeling of lung MSC in mice enabled determination of terminal lineage and localization of ABCG2 cells following intratracheal administration of bleomycin to elicit fibrotic lung injury. Fourteen days following bleomycin injury enhanced green fluorescent protein (eGFP)-labeled lung MSC-derived cells were increased in number and localized to interstitial areas of fibrotic and microvessel remodeling. Finally, gene expression analysis was evaluated to define the response of MSC to bleomycin injury in vivo using ABCG2(pos) MSC isolated during the inflammatory phase postinjury and in vitro bleomycin or transforming growth factor-ß1 (TGF-ß1)-treated cells. MSC responded to bleomycin treatment in vivo with a profibrotic gene program that was not recapitulated in vitro with bleomycin treatment. However, TGF-ß1 treatment induced the appearance of a profibrotic myofibroblast phenotype in vitro. Additionally, when exposed to the profibrotic stimulus, TGF-ß1, ABCG2, and NG2 pericytes demonstrated distinct responses. Our data highlight ABCG2(pos) lung MSC as a novel cell population that contributes to detrimental myofibroblast-mediated remodeling during PF.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Células-Tronco Mesenquimais/fisiologia , Proteínas de Neoplasias/metabolismo , Pericitos/fisiologia , Fibrose Pulmonar/patologia , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Animais , Células Cultivadas , Humanos , Pulmão/irrigação sanguínea , Pulmão/patologia , Camundongos , Miofibroblastos/fisiologia , Fibrose Pulmonar/metabolismo , Fator de Crescimento Transformador beta1/fisiologia
19.
J Card Fail ; 20(12): 1020-6, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25284390

RESUMO

BACKGROUND: Evidence regarding the association of anger proneness with incidence of heart failure is lacking. METHODS AND RESULTS: Anger proneness was ascertained among 13,171 black and white participants of the Atherosclerosis Risk in Communities (ARIC) study cohort with the use of the Spielberger Trait Anger Scale. Incident heart failure events, defined as occurrence of ICD-9-CM code 428.x, were ascertained from participants' medical records during follow-up in the years 1990-2010. Relative hazard of heart failure across categories of trait anger was estimated with the use of Cox proportional hazard models. Study participants (mean age 56.9 [SD 5.7] years) experienced 1,985 incident HF events during 18.5 (SD 4.9) years of follow-up. Incidence of HF was greater among those with high, as compared to those with low or moderate trait anger, with higher incidence observed for men than for women. The relative hazard of incident HF was modestly high among those with high trait anger, compared with those with low or moderate trait anger (age-adjusted hazard ratio for men: 1.44 (95% confidence interval [CI] 1.23-1.69). Adjustment for comorbidities and depressive symptoms attenuated the estimated age-adjusted relative hazard in men to 1.26 (95% CI 1.00-1.60). CONCLUSIONS: Assessment of anger proneness may be necessary in successful prevention and clinical management of heart failure, especially in men.


Assuntos
Ira/fisiologia , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/psicologia , Estresse Psicológico/epidemiologia , Negro ou Afro-Americano/estatística & dados numéricos , Distribuição por Idade , Estudos de Coortes , Intervalos de Confiança , Feminino , Insuficiência Cardíaca/diagnóstico , Hospitalização/estatística & dados numéricos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Modelos de Riscos Proporcionais , Fatores de Risco , Índice de Gravidade de Doença , Distribuição por Sexo , Estresse Psicológico/psicologia , População Branca/estatística & dados numéricos
20.
Cerebrovasc Dis ; 37(3): 203-11, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24557055

RESUMO

BACKGROUND AND PURPOSE: Medical and endovascular treatment options for stroke prevention in patients with symptomatic intracranial stenosis have evolved over the past several decades, but the impact of 2 major multicenter randomized stroke prevention trials on physician practices has not been studied. We sought to determine changes in US physician treatment choices for patients with intracranial atherosclerotic stenosis (ICAS) following 2 NIH-funded clinical trials that studied medical therapies (antithrombotic agents and risk factor control) and percutaneous transluminal angioplasty and stenting (PTAS). METHODS: Anonymous surveys on treatment practices in patients with ICAS were sent to physicians at 3 time points: before publication of the NIH-funded Warfarin-Aspirin Symptomatic Intracranial Disease (WASID) trial (pre-WASID survey, 2004), 1 year after WASID publication (post-WASID survey, 2006) and 1 year after the publication of the NIH-funded Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) trial (post-SAMMPRIS survey, 2012). Neurologists were invited to participate in the pre-WASID survey (n=525). Neurologists and neurointerventionists were invited to participate in the post-WASID (n=598) and post-SAMMPRIS (n=2,080) surveys. The 3 surveys were conducted using web-based survey tools delivered by E-mail, and a fax-based response form delivered by E-mail and conventional mail. Data were analyzed using the χ2 test. RESULTS: Before WASID, there was equipoise between warfarin and aspirin for stroke prevention in patients with ICAS. The number of respondents who recommended antiplatelet treatment for ICAS increased across all 3 surveys for both anterior circulation (pre-WASID=44%, post-WASID=85%, post-SAMMPRIS=94%) and posterior circulation (pre-WASID=36%, post-WASID=74%, post-SAMMPRIS=83%). The antiplatelet agent most commonly recommended after WASID was aspirin, but after SAMMPRIS it was the combination of aspirin and clopidogrel. The percentage of neurologists who recommended PTAS in >25% of ICAS patients increased slightly from pre-WASID (8%) to post-WASID surveys (12%), but then decreased again after SAMMPRIS (6%). The percentage of neurointerventionists who recommended PTAS in >25% of ICAS patients decreased from post-WASID (49%) to post-SAMMPRIS surveys (17%). CONCLUSIONS: The surveyed US physicians' recommended treatments for ICAS differed over the 3 survey periods, reflecting the results of the 2 NIH-funded clinical trials of ICAS and suggesting that these clinical trials changed practice in the USA.


Assuntos
Angioplastia , Artérias Cerebrais/patologia , Fibrinolíticos/uso terapêutico , Arteriosclerose Intracraniana/terapia , Neurologia/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos , Radiologia Intervencionista , Stents , Acidente Vascular Cerebral/prevenção & controle , Angioplastia/estatística & dados numéricos , Aspirina/administração & dosagem , Aspirina/uso terapêutico , Clopidogrel , Constrição Patológica , Quimioterapia Combinada , Uso de Medicamentos , Pesquisas sobre Atenção à Saúde , Humanos , Arteriosclerose Intracraniana/complicações , Arteriosclerose Intracraniana/patologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Comportamento de Redução do Risco , Prevenção Secundária , Stents/estatística & dados numéricos , Acidente Vascular Cerebral/etiologia , Inquéritos e Questionários , Ticlopidina/administração & dosagem , Ticlopidina/análogos & derivados , Ticlopidina/uso terapêutico , Estados Unidos , Varfarina/uso terapêutico
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