Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Sci Transl Med ; 15(682): eadc9653, 2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-36753562

RESUMO

Current therapeutic strategies for treating nonalcoholic steatohepatitis (NASH) have failed to alleviate liver fibrosis, which is a devastating feature leading to hepatic dysfunction. Here, we integrated single-nucleus transcriptomics and epigenomics to characterize all major liver cell types during NASH development in mice and humans. The bifurcation of hepatocyte trajectory with NASH progression was conserved between mice and humans. At the nonalcoholic fatty liver (NAFL) stage, hepatocytes exhibited metabolic adaptation, whereas at the NASH stage, a subset of hepatocytes was enriched for the signatures of cell adhesion and migration, which were mainly demarcated by receptor tyrosine kinase ephrin type B receptor 2 (EphB2). EphB2, acting as a downstream effector of Notch signaling in hepatocytes, was sufficient to induce cell-autonomous inflammation. Knockdown of Ephb2 in hepatocytes ameliorated inflammation and fibrosis in a mouse model of NASH. Thus, EphB2-expressing hepatocytes contribute to NASH progression and may serve as a potential therapeutic target.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Animais , Camundongos , Hepatopatia Gordurosa não Alcoólica/patologia , Fígado/metabolismo , Hepatócitos/metabolismo , Cirrose Hepática/patologia , Inflamação/patologia , Camundongos Endogâmicos C57BL
2.
Mol Cell Proteomics ; 8(11): 2500-14, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19651621

RESUMO

Classical activation of macrophages induces a wide range of signaling and vesicle trafficking events to produce a more aggressive cellular phenotype. The microtubule (MT) cytoskeleton is crucial for the regulation of immune responses. In the current study, we used a large scale proteomics approach to analyze the change in protein composition of the MT-associated protein (MAP) network by macrophage stimulation with the inflammatory cytokine interferon-gamma and the endotoxin lipopolysaccharide. Overall the analysis identified 409 proteins that bound directly or indirectly to MTs. Of these, 52 were up-regulated 2-fold or greater and 42 were down-regulated 2-fold or greater after interferon-gamma/lipopolysaccharide stimulation. Bioinformatics analysis based on publicly available binary protein interaction data produced a putative interaction network of MAPs in activated macrophages. We confirmed the up-regulation of several MAPs by immunoblotting and immunofluorescence analysis. More detailed analysis of one up-regulated protein revealed a role for HSP90beta in stabilization of the MT cytoskeleton during macrophage activation.


Assuntos
Regulação da Expressão Gênica , Macrófagos/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Proteômica/métodos , Animais , Biologia Computacional/métodos , Citoesqueleto/metabolismo , Bases de Dados de Proteínas , Reações Falso-Positivas , Humanos , Lipopolissacarídeos/metabolismo , Ativação de Macrófagos , Camundongos , Modelos Biológicos
3.
J Med Imaging (Bellingham) ; 7(5): 054502, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32999894

RESUMO

Purpose: In vivo optical imaging technologies like high-resolution microendoscopy (HRME) can image nuclei of the oral epithelium. In principle, automated algorithms can then calculate nuclear features to distinguish neoplastic from benign tissue. However, images frequently contain regions without visible nuclei, due to biological and technical factors, decreasing the data available to and accuracy of image analysis algorithms. Approach: We developed the nuclear density-confidence interval (ND-CI) algorithm to determine if an HRME image contains sufficient nuclei for classification, or if a better image is required. The algorithm uses a convolutional neural network to exclude image regions without visible nuclei. Then the remaining regions are used to estimate a confidence interval (CI) for the number of abnormal nuclei per mm 2 , a feature used by a previously developed algorithm (called the ND algorithm), to classify images as benign or neoplastic. The range of the CI determines whether the ND-CI algorithm can classify an image with confidence, and if so, the predicted category. The ND and ND-CI algorithm were compared by calculating their positive predictive value (PPV) and negative predictive value (NPV) on 82 oral biopsies with histopathologically confirmed diagnoses. Results: After excluding the images that could not be classified with confidence, the ND-CI algorithm had higher PPV (65% versus 59%) and NPV (78% versus 75%) than the ND algorithm. Conclusions: The ND-CI algorithm could improve the real-time classification of HRME images of the oral epithelium by informing the user if an improved image is required for diagnosis.

4.
Head Neck ; 42(2): 171-179, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31621979

RESUMO

BACKGROUND: Multimodal optical imaging, incorporating reflectance and fluorescence modalities, is a promising tool to detect oral premalignant lesions in real-time. METHODS: Images were acquired from 171 sites in 66 patient visits for clinical evaluation of oral lesions. An automated algorithm was used to classify lesions as high- or low-risk for neoplasia. Biopsies were acquired at clinically indicated sites and those classified as high-risk by imaging, at the surgeon's discretion. RESULTS: Twenty sites were biopsied based on clinical examination or imaging. Of these, 12 were indicated clinically and by imaging; 58% were moderate dysplasia or worse. Four biopsies were indicated by imaging evaluation only; 75% were moderate dysplasia or worse. Finally, four biopsies were indicated by clinical evaluation only; 75% were moderate dysplasia or worse. CONCLUSION: Multimodal imaging identified more cases of high-grade dysplasia than clinical evaluation, and can improve detection of high grade precancer in patients with oral lesions.


Assuntos
Lesões Pré-Cancerosas , Biópsia , Humanos , Imagem Multimodal , Projetos Piloto , Lesões Pré-Cancerosas/diagnóstico por imagem , Estudos Prospectivos
5.
Cancer Prev Res (Phila) ; 12(11): 791-800, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31451520

RESUMO

Patients with oral potentially malignant disorders (OPMD) must undergo regular clinical surveillance to ensure that any progression to malignancy is detected promptly. Autofluorescence imaging (AFI) is an optical modality that can assist clinicians in detecting early cancers and high-grade dysplasia. Patients with OPMD undergoing surveillance for the development of oral cancer were examined using AFI at successive clinic visits. Autofluorescence images acquired at 133 clinical visits from sites in 15 patients who met inclusion criteria were analyzed quantitatively using an algorithm to calculate the red-to-green pixel intensity (RG ratio). A quantitative AFI threshold for high risk of progression was defined based on the RG ratio and was compared with expert clinical impression and with histopathology when available. Patients were divided into two groups based on their endpoint: surveillance (n = 6) or surgery (n = 9). In the surveillance group, 0 of 6 (0%) of patients were clinically identified as high risk for progression prior to the study endpoint, whereas 1 of 6 (17%) of patients were deemed at high risk for progression based on AFI during the same time period. In the surgery group, 9 of 9 (100%) of patients were clinically identified as high risk prior to the study endpoint, whereas 8 of 9 (89%) of patients were at high risk for progression based on AFI during the same time period. AFI results tracked over time were comparable with expert clinical impression in these patient groups. AFI has the potential to aid clinicians in noninvasively monitoring oral precancer and evaluating OPMDs that require increased surveillance.


Assuntos
Detecção Precoce de Câncer/métodos , Hiperplasia/patologia , Neoplasias Bucais/patologia , Imagem Óptica/métodos , Lesões Pré-Cancerosas/patologia , Progressão da Doença , Humanos , Estudos Longitudinais , Prognóstico , Estudos Retrospectivos
6.
J Biomed Opt ; 24(2): 1-10, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30793567

RESUMO

Oral premalignant lesions (OPLs), such as leukoplakia, are at risk of malignant transformation to oral cancer. Clinicians can elect to biopsy OPLs and assess them for dysplasia, a marker of increased risk. However, it is challenging to decide which OPLs need a biopsy and to select a biopsy site. We developed a multimodal optical imaging system (MMIS) that fully integrates the acquisition, display, and analysis of macroscopic white-light (WL), autofluorescence (AF), and high-resolution microendoscopy (HRME) images to noninvasively evaluate OPLs. WL and AF images identify suspicious regions with high sensitivity, which are explored at higher resolution with the HRME to improve specificity. Key features include a heat map that delineates suspicious regions according to AF images, and real-time image analysis algorithms that predict pathologic diagnosis at imaged sites. Representative examples from ongoing studies of the MMIS demonstrate its ability to identify high-grade dysplasia in OPLs that are not clinically suspicious, and to avoid unnecessary biopsies of benign OPLs that are clinically suspicious. The MMIS successfully integrates optical imaging approaches (WL, AF, and HRME) at multiple scales for the noninvasive evaluation of OPLs.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Neoplasias Bucais/diagnóstico por imagem , Imagem Multimodal/métodos , Imagem Óptica/métodos , Lesões Pré-Cancerosas/diagnóstico por imagem , Algoritmos , Biópsia , Transformação Celular Neoplásica , Endoscopia , Humanos , Microscopia de Fluorescência/métodos , Doenças da Boca/diagnóstico por imagem , Neoplasias Bucais/patologia , Neoplasias Bucais/cirurgia , Reconhecimento Automatizado de Padrão , Sistemas Automatizados de Assistência Junto ao Leito , Reprodutibilidade dos Testes , Software
7.
Artigo em Inglês | MEDLINE | ID: mdl-29631985

RESUMO

Potentially premalignant oral epithelial lesions (PPOELs) are a group of clinically suspicious conditions, of which a small percentage will undergo malignant transformation. PPOELs are suboptimally diagnosed and managed under the current standard of care. Dysplasia is the most well-established marker to distinguish high-risk PPOELs from low-risk PPOELs, and performing a biopsy to establish dysplasia is the diagnostic gold standard. However, a biopsy is limited by morbidity, resource requirements, and the potential for underdiagnosis. Diagnostic adjuncts may help clinicians better evaluate PPOELs before definitive biopsy, but existing adjuncts, such as toluidine blue, acetowhitening, and autofluorescence imaging, have poor accuracy and are not generally recommended. Recently, in vivo microscopy technologies, such as high-resolution microendoscopy, optical coherence tomography, reflectance confocal microscopy, and multiphoton imaging, have shown promise for improving PPOEL patient care. These technologies allow clinicians to visualize many of the same microscopic features used for histopathologic assessment at the point of care.


Assuntos
Transformação Celular Neoplásica/patologia , Diagnóstico Bucal/tendências , Eritroplasia/diagnóstico por imagem , Eritroplasia/patologia , Leucoplasia Oral/diagnóstico por imagem , Leucoplasia Oral/patologia , Neoplasias Bucais/diagnóstico por imagem , Neoplasias Bucais/patologia , Lesões Pré-Cancerosas/diagnóstico por imagem , Lesões Pré-Cancerosas/patologia , Biópsia , Diagnóstico por Imagem , Progressão da Doença , Detecção Precoce de Câncer , Humanos , Fatores de Risco
8.
Cancer Prev Res (Phila) ; 11(8): 465-476, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29903741

RESUMO

Early detection of oral cancer and oral premalignant lesions (OPL) containing dysplasia could improve oral cancer outcomes. However, general dental practitioners have difficulty distinguishing dysplastic OPLs from confounder oral mucosal lesions in low-risk populations. We evaluated the ability of two optical imaging technologies, autofluorescence imaging (AFI) and high-resolution microendoscopy (HRME), to diagnose moderate dysplasia or worse (ModDys+) in 56 oral mucosal lesions in a low-risk patient population, using histopathology as the gold standard, and in 46 clinically normal sites. AFI correctly diagnosed 91% of ModDys+ lesions, 89% of clinically normal sites, and 33% of benign lesions. Benign lesions with severe inflammation were less likely to be correctly diagnosed by AFI (13%) than those without (42%). Multimodal imaging (AFI+HRME) had higher accuracy than either modality alone; 91% of ModDys+ lesions, 93% of clinically normal sites, and 64% of benign lesions were correctly diagnosed. Photos of the 56 lesions were evaluated by 28 dentists of varied training levels, including 26 dental residents. We compared the area under the receiver operator curve (AUC) of clinical impression alone to clinical impression plus AFI and clinical impression plus multimodal imaging using k-Nearest Neighbors models. The mean AUC of the dental residents was 0.71 (range: 0.45-0.86). The addition of AFI alone to clinical impression slightly lowered the mean AUC (0.68; range: 0.40-0.82), whereas the addition of multimodal imaging to clinical impression increased the mean AUC (0.79; range: 0.61-0.90). On the basis of these findings, multimodal imaging could improve the evaluation of oral mucosal lesions in community dental settings. Cancer Prev Res; 11(8); 465-76. ©2018 AACR.


Assuntos
Detecção Precoce de Câncer/métodos , Mucosa Bucal/diagnóstico por imagem , Neoplasias Bucais/prevenção & controle , Imagem Óptica/métodos , Lesões Pré-Cancerosas/diagnóstico por imagem , Adulto , Técnica de Moldagem Odontológica , Progressão da Doença , Endoscopia/instrumentação , Endoscopia/métodos , Estudos de Viabilidade , Humanos , Processamento de Imagem Assistida por Computador , Mucosa Bucal/patologia , Neoplasias Bucais/diagnóstico , Neoplasias Bucais/patologia , Imagem Multimodal/instrumentação , Imagem Multimodal/métodos , Imagem Óptica/instrumentação , Lesões Pré-Cancerosas/patologia , Curva ROC , Adulto Jovem
9.
Clin Cancer Res ; 16(9): 2550-61, 2010 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-20388845

RESUMO

PURPOSE: Melanoma is a common and deadly tumor that upon metastasis to the central nervous system has a median survival duration of <6 months. Activation of the signal transducer and activator of transcription 3 (STAT3) has been identified as a key mediator that drives the fundamental components of melanoma malignancy, including immune suppression in melanoma patients. We hypothesized that WP1193, a novel inhibitor of STAT3 signaling, would enhance the antitumor activity of IFN-alpha against metastatic melanoma. EXPERIMENTAL DESIGN: Combinational therapy of STAT3 blockade agents with IFN-alpha was investigated in a metastatic and an established syngeneic intracerebral murine tumor model of melanoma. The immunologic in vivo mechanisms of efficacy were investigated by T-cell and natural killer (NK) cell cytotoxic assays. RESULTS: IFN-alpha immunotherapy was synergistic with WP1193 showing marked in vivo efficacy against metastatic and established intracerebral melanoma. At autopsy, it was noted that there was a decreased trend in mice with melanoma developing leptomeningeal disease treated with combinational therapy. The combinational approach enhanced both NK-mediated and T-cell-mediated antitumor cytotoxicity. CONCLUSIONS: The immune modulatory effects of STAT3 blockade can enhance the therapeutic efficacy of IFN-alpha immunotherapy by enhancing both innate and adaptive cytotoxic T-cell activities. This combination therapy has the potential in the treatment of metastatic melanoma that is typically refractory to this type of immune therapeutic approach.


Assuntos
Proliferação de Células/efeitos dos fármacos , Interferon-alfa/farmacologia , Melanoma Experimental/tratamento farmacológico , Fator de Transcrição STAT3/metabolismo , Animais , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Cianoacrilatos/química , Cianoacrilatos/farmacologia , Citotoxicidade Imunológica/efeitos dos fármacos , Citotoxicidade Imunológica/imunologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Feminino , Immunoblotting , Fatores Imunológicos/farmacologia , Estimativa de Kaplan-Meier , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Melanoma Experimental/metabolismo , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Metástase Neoplásica , Piridinas/química , Piridinas/farmacologia , Fator de Transcrição STAT3/antagonistas & inibidores , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Resultado do Tratamento
10.
Proteomics ; 5(7): 1953-66, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15816004

RESUMO

Surface-enhanced laser desorption/ionization-mass spectrometry (SELDI-MS) has conventionally been practiced on linear time of flight (TOF) which has low mass accuracy and resolution. Here we demonstrate in an examination of both malignant and nonmalignant endometrial tissue homogenates that high mass accuracy and resolution in the MS stage are crucial. Using a commercially available quadrupole/TOF (QqTOF), we were able to resolve two potential cancer markers, subsequently identified off-line as chaperonin 10 and calgranulin A, that differ by 8 Da in mass. Two off-line protein identification protocols were developed: the first was based on size-exclusion chromatography (SEC), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), protein extraction, trypsin digestion, and matrix-assisted laser desorption/ionization-tandem MS (MALDI-MS/MS); the second on SEC and shotgun nano-liquid chromatography (nanoLC)-MS/MS. Analyses on a cohort of 44 endometrial homogenates showed 22 out of 23 nonmalignant samples had nondetectable to very low abundance of chaperonin 10 and calgranulin A; 17 of the 21 malignant samples had detectable to abundant levels of both proteins. Immunohistochemical staining of a tissue microarray of 32 samples showed that approximately half of malignant endometrial tissues exhibited positive staining for calgranulin A in the malignant epithelium, while 9 out of 10 benign tissues exhibited negative epithelial staining. In addition, macrophages/granulocytes in malignant as well as nonmalignant tissues showed positive staining. No immunostaining occurred in stroma or myometrium. Calgranulin A, in combination with chaperonin 10 and other proteins, may eventually constitute a panel of markers to permit diagnosis and screening of endometrial cancer.


Assuntos
Biomarcadores Tumorais , Calgranulina A/metabolismo , Chaperonina 10/metabolismo , Neoplasias do Endométrio/metabolismo , Calgranulina A/química , Chaperonina 10/química , Neoplasias do Endométrio/química , Feminino , Humanos , Imuno-Histoquímica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
11.
Proteomics ; 5(1): 270-81, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15602768

RESUMO

Proteomic analyses of the proliferative and secretory phases of the human endometrium were carried out to identify proteins and discover differentially expressed proteins using isotope-coded affinity tags, three stages of chromatographic separation and online tandem mass spectrometry (MS/MS). From an initial list of 346 proteins identified by ProICAT, manual inspection of MS/MS spectra and confirmatory searches pared the list down to 119 positively identified proteins. Only five of the proteins showed consistent differential expression. The utility of some of these proteins as indicators of true differential expression in the endometrium is open to discussion. The two proteins with unquestionable differential expressions in the secretory endometrium are: glutamate NMDA receptor subunit zeta 1 precursor and FRAT1. Some of the proteins that show no differential expression have previously been examined in gene-expression studies with similar conclusions.


Assuntos
Endométrio/citologia , Endométrio/metabolismo , Proteoma/biossíntese , Proteínas Adaptadoras de Transdução de Sinal , Cromatografia Líquida , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Precursores de Proteínas/biossíntese , Subunidades Proteicas/biossíntese , Proteínas Proto-Oncogênicas/biossíntese , Receptores de N-Metil-D-Aspartato/biossíntese , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
12.
J Proteome Res ; 3(3): 636-43, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15253447

RESUMO

Endometrial carcinoma is a common malignancy in women, being exceeded in incidence only by that of breast, lung, and colorectal cancers. At present, no serum tumor markers are available for the monitoring of endometrial carcinoma patients, and patients with recurrent disease are detected only following the development of symptoms or abnormalities in imaging assessments. Similarly, no screening tools are available for endometrial carcinoma. Protein profiling by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has proven to be a sensitive and fast method of analysis for small proteins or peptides to yield specific biomarkers. In this study, a variety of normal and malignant endometrial tissue samples were fractionated and analyzed by SELDI-TOF MS (SELDI is a version of MALDI utilizing protein "chips"). A number of proteins displayed differential expression in malignant endometrial tissues. One of the prominent proteins fractionated by weak cation exchange chromatography and displaying enhanced expression in these malignant tissues was identified as chaperonin 10. The increased expression of chaperonin 10 in malignant endometrial tissues was further confirmed by parallel Western blot and immunohistochemistry analyses.


Assuntos
Biomarcadores Tumorais/química , Chaperonina 10/metabolismo , Neoplasias do Endométrio/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Proteoma , Biomarcadores Tumorais/sangue , Feminino , Humanos , Imuno-Histoquímica , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
13.
J Biol Chem ; 278(17): 15297-303, 2003 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-12586839

RESUMO

The phosphorylation status of the myocyte enhancer factor 2 (MEF2) transcriptional regulator is a critical determinant of its tissue-specific functions. However, due to the complexity of its phosphorylation pattern in vivo, a systematic inventory of MEF2A phosphorylation sites in mammalian cells has been difficult to obtain. We employed modern affinity purification techniques, combined with mass spectrometry, to identify several novel MEF2 phosphoacceptor sites. These include an evolutionarily conserved KSP motif, which we show is important in regulating the stability and function of MEF2A. Also, an indirect pathway in which a protein kinase casein kinase 2 phosphoacceptor site is phosphorylated by activation of p38 MAPK signaling was documented. Together, these findings identify several novel aspects of MEF2 regulation that may prove important in the control of gene expression in neuronal and muscle cells.


Assuntos
Sequência Conservada/fisiologia , Proteínas de Ligação a DNA/metabolismo , Fatores de Transcrição/metabolismo , Motivos de Aminoácidos/fisiologia , Animais , Sítios de Ligação , Células COS , Caseína Quinase II , Cromatografia de Afinidade , Proteínas de Ligação a DNA/isolamento & purificação , Proteínas de Ligação a DNA/fisiologia , Regulação da Expressão Gênica , Células HeLa , Humanos , Proteínas de Domínio MADS , Sistema de Sinalização das MAP Quinases , Fatores de Transcrição MEF2 , Espectrometria de Massas , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fatores de Regulação Miogênica , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Alinhamento de Sequência , Fatores de Transcrição/isolamento & purificação , Fatores de Transcrição/fisiologia , Transfecção , Proteínas Quinases p38 Ativadas por Mitógeno
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA