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1.
Eur Rev Med Pharmacol Sci ; 26(7): 2511-2517, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35442466

RESUMO

OBJECTIVE: The aim of this study is to compare the risk of venous thromboembolic events (VTE) between patients suspending and continuing estrogen therapy perioperatively, in male to female gender-affirming surgery (vaginoplasty). MATERIALS AND METHODS: The authors conducted a systematic review and meta-analysis of existing research on male to female gender-affirming study, which compared the risk of VTE among the usage of estrogen perioperatively. RESULTS: A total of 209 studies were identified as potentially eligible among PubMed, Embase, and Cochrane library databases. Among the studies, 191 studies were excluded due to their abstract inappropriateness. Out of the remaining 18 studies, only 3 articles were eligible and were finally included. Meta-analysis was performed and showed odds ratio of 0.77 (95% CI: 0.04, 14.01). CONCLUSIONS: Perioperative estrogen therapy does not increase VTE risk on male to female gender-affirming surgery. Therefore, estrogen therapy may be continued perioperatively in vaginoplasty. More prospective studies are needed.


Assuntos
Pessoas Transgênero , Tromboembolia Venosa , Trombose Venosa , Estrogênios/efeitos adversos , Feminino , Terapia de Reposição Hormonal , Humanos , Masculino , Tromboembolia Venosa/induzido quimicamente , Tromboembolia Venosa/epidemiologia
2.
J Exp Med ; 217(4)2020 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-31999304

RESUMO

Aberrant NLRP3 inflammasome activation contributes to the development of endotoxemia. The importance of negative regulation of NLRP3 inflammasomes remains poorly understood. Here, we show that the E3 ubiquitin ligase Cbl-b is essential for preventing endotoxemia induced by a sub-lethal dose of LPS via a caspase-11/NLRP3-dependent manner. Further studies show that NLRP3 undergoes both K63- and K48-linked polyubiquitination. Cbl-b binds to the K63-ubiquitin chains attached to the NLRP3 leucine-rich repeat domain (LRR) via its ubiquitin-associated region (UBA) and then targets NLRP3 at K496 for K48-linked ubiquitination and proteasome-mediated degradation. We also identify RNF125 as an additional E3 ubiquitin ligase that initiates K63-linked ubiquitination of the NLRP3 LRR domain. Therefore, NLRP3 is sequentially ubiquitinated by K63- and K48-linked ubiquitination, thus keeping the NLRP3 inflammasomes in check and restraining endotoxemia.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Endotoxemia/metabolismo , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteínas Proto-Oncogênicas c-cbl/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/fisiologia , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Complexo de Endopeptidases do Proteassoma/metabolismo , Ubiquitina/metabolismo
3.
BJOG ; 127(7): 897-904, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31961472

RESUMO

OBJECTIVE: To describe and compare baseline renal anatomy and renal function in patients with obstetric fistulas, and to evaluate whether preoperative renal testing and imaging may aid with operative decision making. DESIGN: A prospective cohort study. SETTING: Fistula Care Centre in Malawi. POPULATION: Women with an obstetric fistula. METHODS: Baseline creatinine testing and renal ultrasounds were performed. Surgeons completed a short questionnaire on the usefulness of creatinine and renal ultrasound on operative decision making. MAIN OUTCOME MEASURES: Baseline creatinine and renal ultrasound findings. RESULTS: Four surgeons performed operations on 85 patients. The mean creatinine in patients with vesicovaginal fistulas (VVF) was 0.60 ng/ml versus patients with uretero-vaginal fistulas (UVF) (0.79 ng/ml, P = 0.012). When a grade 3 or more hydronephrosis is absent on renal ultrasound, the negative predictive value of the presence of UVF is 93.3% (95% confidence interval [CI] 88.6-96.2) with a specificity of 97.2% (95% CI 90.3-99.6). In cases of UVF, surgeons found the renal ultrasound results useful or very useful 87.5% of the time, and the creatinine useful or very useful 75% of the time. CONCLUSION: In this pilot study, most patients with obstetric fistulas presented with a normal creatinine. In the absence of a grade 3 hydronephrosis or above on renal ultrasound, the probability of not having a UVF is 93.3%. Surgeons should consider performing preoperative renal ultrasound testing in all patients with an obstetric fistula, particularly in women with a prior laparotomy, as this population has risk factors for ureterovaginal fistula. TWEETABLE ABSTRACT: Most patients with obstetric fistulas have normal renal function. Preoperative renal ultrasounds should be performed.


Assuntos
Rim/diagnóstico por imagem , Complicações do Trabalho de Parto , Fístula Urinária , Fístula Vesicovaginal , Adulto , Feminino , Humanos , Testes de Função Renal/métodos , Malaui/epidemiologia , Complicações do Trabalho de Parto/diagnóstico , Complicações do Trabalho de Parto/epidemiologia , Complicações do Trabalho de Parto/cirurgia , Avaliação de Processos e Resultados em Cuidados de Saúde , Gravidez , Cuidados Pré-Operatórios/métodos , Cuidados Pré-Operatórios/normas , Estudos Prospectivos , Melhoria de Qualidade , Procedimentos Cirúrgicos Operatórios/efeitos adversos , Procedimentos Cirúrgicos Operatórios/métodos , Ultrassonografia/métodos , Fístula Urinária/diagnóstico , Fístula Urinária/epidemiologia , Fístula Urinária/etiologia , Fístula Urinária/cirurgia , Fístula Vesicovaginal/epidemiologia , Fístula Vesicovaginal/etiologia , Fístula Vesicovaginal/cirurgia
4.
PLoS Negl Trop Dis ; 13(7): e0007533, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31260451

RESUMO

Leishmaniasis is a global health problem with an estimated report of 2 million new cases every year and more than 1 billion people at risk of contracting this disease in endemic areas. The innate immune system plays a central role in controlling L. major infection by initiating a signaling cascade that results in production of pro-inflammatory cytokines and recruitment of both innate and adaptive immune cells. Upon infection with L. major, CXCL1 is produced locally and plays an important role in the recruitment of neutrophils to the site of infection. Herein, we report that L. major specifically targets murine CXCL1 for degradation. The degradation of CXCL1 is not dependent on host factors as L. major can directly degrade recombinant CXCL1 in a cell-free system. Using mass spectrometry, we discovered that the L. major protease cleaves at the C-terminal end of murine CXCL1. Finally, our data suggest that L. major metalloproteases are involved in the direct cleavage and degradation of CXCL1, and a synthetic peptide spanning the CXCL1 cleavage site can be used to inhibit L. major metalloprotease activity. In conclusion, our study has identified an immune evasion strategy employed by L. major to evade innate immune responses in mice, likely reservoirs in the endemic areas, and further highlights that targeting these L. major metalloproteases may be important in controlling infection within the reservoir population and transmittance of the disease.


Assuntos
Quimiocina CXCL1/metabolismo , Interações Hospedeiro-Patógeno/imunologia , Evasão da Resposta Imune , Leishmania major/imunologia , Animais , Quimiocina CXCL1/genética , Imunidade Inata , Leishmania major/enzimologia , Leishmaniose , Metaloproteases/metabolismo , Camundongos , Proteínas Recombinantes/imunologia , Transdução de Sinais
5.
Br J Surg ; 106(6): 729-734, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30816996

RESUMO

BACKGROUND: For patients with intermediate-thickness melanoma, surveillance of regional lymph node basins by clinical examination alone has been reported to result in a larger number of lymph nodes involved by melanoma than if patients had initial sentinel node biopsy and completion dissection. This may result in worse regional control. A prospective study of both regular clinical examination and ultrasound surveillance was conducted to assess the effectiveness of these modalities. METHODS: Between 2010 and 2014, patients with melanoma of thickness 1·2-3·5 mm who had under-gone wide local excision but not sentinel node biopsy were recruited to a prospective observational study of regular clinical and ultrasound nodal surveillance. The primary endpoint was nodal burden within a dissected regional lymph node basin. Secondary endpoints included locoregional or distant relapse, progression-free and overall survival. RESULTS: Ninety patients were included in the study. After a median follow-up of 52 months, ten patients had developed nodal relapse as first recurrence, four had locoregional disease outside of an anatomical nodal basin as the first site of relapse and six had relapse with distant disease. None of the patients who developed relapse within a nodal basin presented with unresectable nodal disease. The median number of involved lymph nodes in patients undergoing lymphadenectomy for nodal relapse was 1 (range 1-2; mean 1·2). CONCLUSION: This study suggests that ultrasound surveillance of regional lymph node basins is safe for patients with melanoma who undergo a policy of nodal surveillance.


Assuntos
Linfonodos/diagnóstico por imagem , Melanoma/patologia , Cuidados Pós-Operatórios/métodos , Neoplasias Cutâneas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Excisão de Linfonodo , Linfonodos/patologia , Metástase Linfática , Masculino , Melanoma/diagnóstico por imagem , Melanoma/mortalidade , Melanoma/cirurgia , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico por imagem , Estudos Prospectivos , Neoplasias Cutâneas/diagnóstico por imagem , Neoplasias Cutâneas/mortalidade , Neoplasias Cutâneas/cirurgia , Análise de Sobrevida , Resultado do Tratamento
6.
Am J Respir Crit Care Med ; 197(10): 1308-1318, 2018 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-29327941

RESUMO

RATIONALE: Classical interpretation of cystic fibrosis (CF) lung disease pathogenesis suggests that infection initiates disease progression, leading to an exuberant inflammatory response, excessive mucus, and ultimately bronchiectasis. Although symptomatic antibiotic treatment controls lung infections early in disease, lifelong bacterial residence typically ensues. Processes that control the establishment of persistent bacteria in the CF lung, and the contribution of noninfectious components to disease pathogenesis, are poorly understood. OBJECTIVES: To evaluate whether continuous antibiotic therapy protects the CF lung from disease using a ferret model that rapidly acquires lethal bacterial lung infections in the absence of antibiotics. METHODS: CFTR (cystic fibrosis transmembrane conductance regulator)-knockout ferrets were treated with three antibiotics from birth to several years of age and lung disease was followed by quantitative computed tomography, BAL, and histopathology. Lung disease was compared with CFTR-knockout ferrets treated symptomatically with antibiotics. MEASUREMENTS AND MAIN RESULTS: Bronchiectasis was quantified from computed tomography images. BAL was evaluated for cellular differential and features of inflammatory cellular activation, bacteria, fungi, and quantitative proteomics. Semiquantitative histopathology was compared across experimental groups. We demonstrate that lifelong antibiotics can protect the CF ferret lung from infections for several years. Surprisingly, CF animals still developed hallmarks of structural bronchiectasis, neutrophil-mediated inflammation, and mucus accumulation, despite the lack of infection. Quantitative proteomics of BAL from CF and non-CF pairs demonstrated a mucoinflammatory signature in the CF lung dominated by Muc5B and neutrophil chemoattractants and products. CONCLUSIONS: These findings implicate mucoinflammatory processes in the CF lung as pathogenic in the absence of clinically apparent bacterial and fungal infections.


Assuntos
Regulador de Condutância Transmembrana em Fibrose Cística/genética , Infecções/microbiologia , Inflamação/microbiologia , Pneumopatias/microbiologia , Pulmão/microbiologia , Pulmão/fisiopatologia , Infecções Respiratórias/microbiologia , Animais , Modelos Animais de Doenças , Furões/microbiologia , Infecções/fisiopatologia , Inflamação/fisiopatologia , Pneumopatias/fisiopatologia , Infecções Respiratórias/fisiopatologia
7.
BJOG ; 125(6): 751-756, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28981186

RESUMO

Gynecologic and plastic surgeons collaborate to improve vaginal reconstruction for women with vaginal stenosis and obstetric fistula. As these cases occur typically in low-resource settings, the Singapore flap is a useful technique given its reliability, safety, ease of dissection, and minimal need for additional supplies. The fasciocutaneous flap maintains cutaneous innervation and vasculature and does not require stenting. The surgical collaboration has made it possible to provide functional vaginal reconstruction as a part of the overall care of obstetric fistula patients. The technique shows promise for improving sexual function for women with obstetric fistula and may also enhance healing. TWEETABLE ABSTRACT: Gynecologic & plastic surgeons collaborate to improve vaginal reconstruction for women with obstetric fistula.


Assuntos
Procedimentos de Cirurgia Plástica/métodos , Complicações na Gravidez/cirurgia , Retalhos Cirúrgicos , Vagina/cirurgia , Fístula Vesicovaginal/cirurgia , Constrição Patológica/etiologia , Constrição Patológica/cirurgia , Feminino , Humanos , Gravidez , Complicações na Gravidez/etiologia , Complicações na Gravidez/patologia , Resultado do Tratamento , Vagina/patologia , Fístula Vesicovaginal/complicações , Fístula Vesicovaginal/patologia , Adulto Jovem
8.
Clin Radiol ; 69(10): e422-31, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25064764

RESUMO

Masses involving the abdominal wall arise from a large number of aetiologies. This article will describe a diagnostic approach, imaging features of the most common causes of abdominal wall masses, and highly specific characteristics of less common diseases. A diagnostic algorithm for abdominal wall masses combines clinical history and imaging appearances to classify lesions.


Assuntos
Neoplasias Abdominais/diagnóstico , Parede Abdominal/patologia , Diagnóstico por Imagem/métodos , Neoplasias de Tecidos Moles/diagnóstico , Meios de Contraste , Diagnóstico por Imagem/normas , Feminino , Humanos , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Anamnese , Guias de Prática Clínica como Assunto , Radiografia Abdominal/métodos , Tomografia Computadorizada por Raios X/métodos
9.
Am J Respir Cell Mol Biol ; 50(3): 502-12, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24074402

RESUMO

Chronic bacterial lung infections in cystic fibrosis (CF) are caused by defects in the CF transmembrane conductance regulator chloride channel. Previously, we described that newborn CF transmembrane conductance regulator-knockout ferrets rapidly develop lung infections within the first week of life. Here, we report a more slowly progressing lung bacterial colonization phenotype observed in juvenile to adult CF ferrets reared on a layered antibiotic regimen. Even on antibiotics, CF ferrets were still very susceptible to bacterial lung infection. The severity of lung histopathology ranged from mild to severe, and variably included mucus obstruction of the airways and submucosal glands, air trapping, atelectasis, bronchopneumonia, and interstitial pneumonia. In all CF lungs, significant numbers of bacteria were detected and impaired tracheal mucociliary clearance was observed. Although Streptococcus, Staphylococcus, and Enterococcus were observed most frequently in the lungs of CF animals, each animal displayed a predominant bacterial species that accounted for over 50% of the culturable bacteria, with no one bacterial taxon predominating in all animals. Matrix-assisted laser desorption-ionization time-of-flight mass spectrometry fingerprinting was used to quantify lung bacteria in 10 CF animals and demonstrated Streptococcus, Staphylococcus, Enterococcus, or Escherichia as the most abundant genera. Interestingly, there was significant overlap in the types of bacteria observed in the lung and intestine of a given CF animal, including bacterial taxa unique to the lung and gut of each CF animal analyzed. These findings demonstrate that CF ferrets develop lung disease during the juvenile and adult stages that is similar to patients with CF, and suggest that enteric bacterial flora may seed the lung of CF ferrets.


Assuntos
Translocação Bacteriana , Regulador de Condutância Transmembrana em Fibrose Cística/deficiência , Fibrose Cística/microbiologia , Furões/metabolismo , Intestinos/microbiologia , Pulmão/microbiologia , Infecções Respiratórias/microbiologia , Fatores Etários , Animais , Animais Geneticamente Modificados , Antibacterianos/administração & dosagem , Fibrose Cística/tratamento farmacológico , Fibrose Cística/genética , Fibrose Cística/metabolismo , Fibrose Cística/fisiopatologia , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Modelos Animais de Doenças , Progressão da Doença , Furões/genética , Predisposição Genética para Doença , Intestinos/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/fisiopatologia , Depuração Mucociliar , Fenótipo , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/genética , Infecções Respiratórias/metabolismo , Infecções Respiratórias/fisiopatologia
11.
Proteomics ; 9(1): 182-93, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19053080

RESUMO

Secreted proteins play a pivotal role in cellular functions. To better understand malignant behavior, we adapted stable isotopic labeling with amino acids in cell culture technology to identify and quantify proteins differentially released into the extracellular media by a pair of normal and malignant breast-cancer cell lines. Approximately 380 non-redundant proteins were quantified in serum-free media. Of the assigned proteins, 62% are classified secreted in protein databases and an additional 25% are designated secreted in the literature. A number of growth factors were found differentially regulated. Tumor necrosis factor, pigment epithelial-differentiating factor and stem-cell growth factor precursor showed decreased expression in breast-cancer cell line, whereas Inhibin beta and macrophage migration inhibitory factor show increased expression. Interestingly, protease inhibitors, including plasma protease (C1) inhibitor, PZP precursor, and SerpinE2 were significantly down-regulated in cancer cell line as were angiostatic factors from extracellular matrix (ECM) such as endorepillin. Further, the C-terminal fragment of type XVIII collagen, endostatin, a potent angiostatic factor, was down-regulated as well whereas extracellular collagens and osteoblast-specific factor 2 (OSF-2), were up-regulated. Differential expression and secretion of SerpinE2 and OSF-2 were confirmed using Western blotting. These results corroborate models of invasive tumors sustained by elaborate coordination of stromal cells via chemokines and growth factors, while protease inhibitors remodel the ECM to stimulate angiogenesis.


Assuntos
Neoplasias da Mama/química , Proteínas/análise , Aminoácidos/química , Aminoácidos/metabolismo , Biomarcadores/análise , Neoplasias da Mama/diagnóstico , Técnicas de Cultura de Células , Linhagem Celular , Linhagem Celular Tumoral , Citocinas/análise , Matriz Extracelular/química , Feminino , Regulação da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/análise , Proteínas/metabolismo , Reprodutibilidade dos Testes , Inibidores de Serina Proteinase/análise
12.
J Proteome Res ; 5(10): 2632-41, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17022634

RESUMO

More than 50% of all major drug targets are membrane proteins, and their role in cell-cell interaction and signal transduction is a vital concern. By culturing normal and malignant breast cancer cells with light or heavy isotopes of amino acids (SILAC), followed by cell fractionation, 1D gel separation of crude membrane proteins, and analysis of the digests using nanoelectrospray LC-MS/MS, we have quantified 1600 gene products that group into 997 protein families with approximately 830 membrane or membrane-associated proteins; 100 unknown, unnamed, or hypothetical proteins; and 65 protein families classified as ribosomal, heat shock, or histone proteins. A number of proteins show increased expression levels in malignant breast cancer cells, such as autoantigen p542, osteoblast-specific factor 2 (OSF-2), 4F2 heavy chain antigen, 34 kDa nucleolar scleroderma antigen, and apoptosis inhibitor 5. The expression of other proteins, such as membrane alanine aminopeptidase (CD13), epididymal protein, macroglobulin alpha2, PZP_HUMAN, and transglutaminase C, decreased in malignant breast cancer cells, whereas the majority of proteins remained unchanged when compared to the corresponding nonmalignant samples. Downregulation of CD13 and upregulation of OSF-2 were confirmed by immunohistochemistry using human tissue arrays with breast carcinomas. Furthermore, at least half the gene products displaying an expression change of 5-fold or higher have been described previously in the literature as having an association with cancerous malignancy. These results indicate that SILAC is a powerful technique that can be extended to the discovery of membrane-bound antigens that may be used to phenotype diseased cells.


Assuntos
Neoplasias da Mama/química , Carcinoma/química , Proteínas de Membrana/análise , Proteínas de Neoplasias/análise , Proteoma/análise , Proteômica/métodos , Idoso , Sequência de Aminoácidos , Mama/química , Mama/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Carcinoma/genética , Carcinoma/metabolismo , Fracionamento Celular , Membrana Celular/química , Cromatografia Líquida , Regulação para Baixo , Feminino , Humanos , Imunoquímica , Espectrometria de Massas , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Peptídeos/análise , Proteoma/genética , Proteoma/metabolismo , Células Tumorais Cultivadas , Regulação para Cima
13.
Proteomics ; 6(16): 4554-64, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16858728

RESUMO

Phosphorylation by the constitutively activated BCR-ABL tyrosine kinase is associated with the pathogenesis of the human chronic myelogenous leukemia (CML). It is difficult to characterize kinase response to stimuli or drug treatment because regulatory phosphorylation events are largely transient changes affecting low abundance proteins. Stable isotope labeling with amino acids in cell culture (SILAC) has emerged as a pivotal technology for quantitative proteomics. By metabolically labeling proteins with light or heavy tyrosine, we are able to quantify the change in phosphorylation of BCR-ABL kinase and its substrates in response to drug treatment in human CML cells. In this study, we observed that BCR-ABL kinase is phosphorylated at tyrosines 393 and 644, and that SH2-domain containing inositol phosphatase (SHIP)-2 and downstream of kinase (Dok)-2 are phosphorylated at tyrosine 1135 and 299, respectively. Based on the relative intensity of isotopic peptide pairs, we demonstrate that the level of phosphorylation of BCR-ABL kinase as well as SHIP-2 and Dok-2 is reduced approximately 90% upon treatment with Imatinib, a specific inhibitor of BCR-ABL kinase. Furthermore, proteins, such as SHIP-1, SH2-containing protein (SHC) and Casitas B-lineage lymphoma proto-oncogene (CBL), are also regulated by Imatinib. These results demonstrate the simplicity and utility of SILAC as a method to quantify dynamic changes in phosphorylation at specific sites in response to stimuli or drug treatment in cell culture.


Assuntos
Antineoplásicos/farmacologia , Piperazinas/farmacologia , Proteínas Tirosina Quinases/metabolismo , Pirimidinas/farmacologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Sequência de Aminoácidos , Benzamidas , Linhagem Celular Tumoral , Proteínas de Fusão bcr-abl , Humanos , Mesilato de Imatinib , Marcação por Isótopo , Leucemia Mielogênica Crônica BCR-ABL Positiva , Dados de Sequência Molecular , Proteína Oncogênica v-cbl/metabolismo , Fosfatidilinositol-3,4,5-Trifosfato 5-Fosfatases , Fosfoproteínas/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Fosforilação , Proto-Oncogene Mas , Tirosina/metabolismo
14.
Rapid Commun Mass Spectrom ; 18(23): 2953-9, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15536629

RESUMO

Monovalent cations often associate with peptides and proteins under mass spectrometry (MS) conditions, resulting in a discernable, but often misleading, adduct cluster pattern. These adduct cluster peaks reduce the signal intensity of specific peptide species by splitting the ion population into multiple mass peaks, suppressing the ionization of neighboring low-abundance peaks, and interfering with identification of post-translational modifications. Further, monovalent contaminants tend to form a distribution of matrix cluster peaks in matrix-associated laser desorption/ionization time-of-flight (MALDI-TOF) spectra causing interference and suppression in the mass range below 1400 Da. The most common method for reduction or elimination of adduct clusters is solid-phase extraction via a pipette tip or spin column, which often leads to loss of low-abundance peptide components. In this study we describe the use of a commercially available surfactant blend that markedly reduces the adduction of monovalent cations during peptide analysis by MALDI-TOFMS.


Assuntos
Peptídeos/análise , Potássio/química , Sódio/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Bovinos , Soroalbumina Bovina/química , Tensoativos
15.
J Biol Chem ; 279(52): 54079-87, 2004 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-15492002

RESUMO

The enzymatic activity of the vitamin K-dependent proteins requires the post-translational conversion of specific glutamic acids to gamma-carboxy-glutamic acid by the integral membrane enzyme, gamma-glutamyl carboxylase. Whether or not cysteine residues are important for carboxylase activity has been the subject of a number of studies. In the present study we used carboxylase with point mutations at cysteines, chemical modification, and mass spectrometry to examine this question. Mutation of any of the free cysteine residues to alanine or serine had little effect on carboxylase activity, although C343A mutant carboxylase had only 38% activity compared with that of wild type. In contrast, treatment with either thiol-reactive reagent 4-acetamido-4'-maleimidylstilbene-2,2'-disulfonic acid, disodium salt, or sodium tetrathionate, caused complete loss of activity. We identified the residues modified, using matrix-assisted laser desorption/ionization time of flight mass spectrometry, as Cys(323) and Cys(343). According to our results, these residues are on the cytoplasmic side of the microsomal membrane, whereas catalytic residues are expected to be on the lumenal side of the membrane. Carboxylase was partially protected from chemical modification by factor IXs propeptide. Although all mutant carboxylases bound propeptide with normal affinity, chemical modification caused a >100-fold decrease in carboxylase affinity for the consensus propeptide. We conclude that cysteine residues are not directly involved in carboxylase catalysis, but chemical modification of Cys(323) and Cys(343) may disrupt the three-dimensional structure, resulting in inactivation.


Assuntos
Carbono-Carbono Ligases/química , Carbono-Carbono Ligases/metabolismo , Cisteína/química , Sequência de Aminoácidos , Sítios de Ligação , Carbono-Carbono Ligases/genética , Cisteína/genética , Inibidores Enzimáticos/farmacologia , Maleimidas/farmacologia , Dados de Sequência Molecular , Estrutura Molecular , Mutagênese Sítio-Dirigida , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Mutação Puntual , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Estilbenos/farmacologia , Relação Estrutura-Atividade , Sulfatos/farmacologia , Reagentes de Sulfidrila/farmacologia , Ácidos Sulfônicos/farmacologia , Tripsina/metabolismo , Vitamina K/farmacologia
16.
Cancer Res ; 63(20): 6928-34, 2003 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-14583493

RESUMO

The growing knowledge of the tight connection between apoptosis and cancer has lead to an explosion of research revolving around apoptotic induction with chemotherapeutic agents and small molecule inhibitors. The chemotherapeutic agent paclitaxel (Taxol) activates mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase and, combined with MEK inhibition, synergistically enhances apoptosis. Here we implement a proteomic approach using two-dimensional gels coupled with mass spectrometry to identify proteins altered with this coordinated combination treatment. We found that the combined treatment of paclitaxel and MEK inhibitor uniquely altered the proteins RS/DJ-1 (RNA-binding regulatory subunit/DJ-1 PARK7) and RhoGDIalpha (Rho GDP-dissociation inhibitor alpha). Functional proteomic analysis by exogenous expression or short interfering RNA targeting confirmed a role in survival and apoptosis for these proteins. Analysis of primary lung tumors with matched adjacent normal tissue confirmed RS/DJ-1 overexpression in non-small cell lung carcinoma. This study shows the power of proteomic profiling coupled with functional analysis for the discovery of novel molecular targets and potential cancer cell-specific biomarkers.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Inibidores de Dissociação do Nucleotídeo Guanina/metabolismo , Neoplasias Pulmonares/metabolismo , MAP Quinase Quinase Quinase 1 , Proteínas Oncogênicas/metabolismo , Butadienos/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular Tumoral , Inibidores Enzimáticos/administração & dosagem , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Nitrilas/administração & dosagem , Paclitaxel/administração & dosagem , Proteína Desglicase DJ-1 , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteômica/métodos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Inibidores da Dissociação do Nucleotídeo Guanina rho-Específico
17.
J Am Soc Mass Spectrom ; 14(10): 1076-85, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14530088

RESUMO

A method has been developed for rapid and sensitive identification of epitope-containing peptides, based on direct MALDI-MS/MS analysis of epitope-containing peptides affinity bound to affinity beads. This technique provides sequence information of the epitope that allows unambiguous identification of the epitope either by database searching or de novo sequencing. With MALDI-MS, affinity beads with bound peptides can be placed directly on the MALDI target and analyzed. Coupling a MALDI source to an orthogonal injection quadrupole time-of-flight (QqTOF) mass spectrometer allows direct sequencing of the bound peptides. In contrast to ESI-MS/MS, elution of the affinity-bound peptides followed by additional concentration and purification steps is not required, thus reducing the potential for sample loss. Direct mass spectrometric sequencing of affinity-bound peptides eliminates the need for chemical or enzymatic sequencing. Other advantages of this direct MALDI-MS/MS analysis of epitope-containing peptides bound to the affinity beads include its sensitivity (femtomole levels) and speed. In addition, direct analysis of peptides on affinity beads does not adversely affect the high mass accuracy of a QqTOF, and database searching can be performed on the MS/MS spectra obtained. In proof-of-principle experiments, this method has been demonstrated on beads containing immobilized antibodies against phosphotyrosine, the c-myc epitope tag, as well as immobilized avidin. Furthermore, de novo sequencing of epitope-containing peptides is demonstrated. The first application of this method was with anti-FLAG-tag affinity beads, where direct MALDI MS/MS was used to determine an unexpected enzymatic cleavage site on a growth factor protein.


Assuntos
Anticorpos/imunologia , Epitopos/análise , Epitopos/imunologia , Peptídeos/análise , Peptídeos/imunologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Sequência de Aminoácidos , Anticorpos Fosfo-Específicos/imunologia , Especificidade de Anticorpos , Avidina/metabolismo , Biotina/metabolismo , Epitopos/química , Microesferas , Peptídeos/química , Fosfotirosina/imunologia , Ligação Proteica , Proteínas Proto-Oncogênicas c-myc/imunologia , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/instrumentação , Fatores de Tempo
18.
J Biol Chem ; 278(46): 45468-75, 2003 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-12963724

RESUMO

Vitamin K-dependent gamma-glutamyl carboxylase is a 758 amino acid integral membrane glycoprotein that catalyzes the post-translational conversion of certain protein glutamate residues to gamma-carboxyglutamate. Carboxylase has ten cysteine residues, but their form (sulfhydryl or disulfide) is largely unknown. Pudota et al. in Pudota, B. N., Miyagi, M., Hallgren, K. W., West, K. A., Crabb, J. W., Misono, K. S., and Berkner, K. L. (2000) Proc. Natl. Acad. Sci. U. S. A. 97, 13033-13038 reported that Cys-99 and Cys-450 are the carboxylase active site residues. We determined the form of all cysteines in carboxylase using in-gel protease digestion and matrix-assisted laser desorption/ionization mass spectrometry. The spectrum of non-reduced, trypsin-digested carboxylase revealed a peak at m/z 1991.9. Only this peak disappeared in the spectrum of the reduced sample. This peak's m/z is consistent with the mass of peptide 92-100 (Cys-99) disulfide-linked with peptide 446-453 (Cys-450). To confirm its identity, the m/z 1991.9 peak was isolated by a timed ion selector as the precursor ion for further MS analysis. The fragmentation pattern exhibited two groups of triplet ions characteristic of the symmetric and asymmetric cleavage of disulfide-linked tryptic peptides containing Cys-99 and Cys-450. Mutation of either Cys-99 or Cys-450 caused loss of enzymatic activity. We created a carboxylase variant with both C598A and C700A, leaving Cys-450 as the only remaining cysteine residue in the 60-kDa fragment created by limited trypsin digestion. Analysis of this fully active mutant enzyme showed a 30- and the 60-kDa fragment were joined under non-reducing conditions, thus confirming Cys-450 participates in a disulfide bond. Our results indicate that Cys-99 and Cys-450 form the only disulfide bond in carboxylase.


Assuntos
Carbono-Carbono Ligases/química , Carbono-Carbono Ligases/metabolismo , Vitamina K/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Linhagem Celular , Quimotripsina/farmacologia , Cisteína/química , Dissulfetos , Glicosilação , Humanos , Insetos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Mutação , Peptídeos/química , Estrutura Terciária de Proteína , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Tripsina/farmacologia
19.
J Biol Chem ; 277(36): 33456-67, 2002 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-12080045

RESUMO

Herpes simplex virus type 1 utilizes cell surface heparan sulfate as receptors to infect target cells. The unique heparan sulfate saccharide sequence offers the binding site for viral envelope proteins and plays critical roles in assisting viral infections. A specific 3-O-sulfated heparan sulfate is known to facilitate the entry of herpes simplex virus 1 into cells. The 3-O-sulfated heparan sulfate is generated by the heparan sulfate d-glucosaminyl-3-O-sulfotransferase isoform 3 (3-OST-3), and it provides binding sites for viral glycoprotein D (gD). Here, we report the purification and structural characterization of an oligosaccharide that binds to gD. The isolated gD-binding site is an octasaccharide, and has a binding affinity to gD around 18 microm, as determined by affinity coelectrophoresis. The octasaccharide was prepared and purified from a heparan sulfate oligosaccharide library that was modified by purified 3-OST-3 enzyme. The molecular mass of the isolated octasaccharide was determined using both nanoelectrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry. The results from the sequence analysis suggest that the structure of the octasaccharide is a heptasulfated octasaccharide. The proposed structure of the octasaccharide is DeltaUA-GlcNS-IdoUA2S-GlcNAc-UA2S-GlcNS-IdoUA2S-GlcNH(2)3S6S. Given that the binding of 3-O-sulfated heparan sulfate to gD can mediate viral entry, our results provide structural information about heparan sulfate-assisted viral entry.


Assuntos
Polissacarídeos/química , Proteínas do Envelope Viral/química , Animais , Cromatografia Líquida de Alta Pressão , Dissacarídeos/química , Eletroforese Capilar , Insetos , Cinética , Modelos Químicos , Polissacarídeos/metabolismo , Ligação Proteica , Isoformas de Proteínas , Estrutura Terciária de Proteína , Proteínas Recombinantes de Fusão/metabolismo , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Fatores de Tempo , Raios Ultravioleta , Proteínas do Envelope Viral/metabolismo
20.
J Rheumatol Suppl ; 64: 28-31, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11642500

RESUMO

There is little information about the clinical course of patients with rheumatoid arthritis (RA) who relapse after autologous blood stem cell transplantation (ASCT). We describe 6 patients with severe RA who received ASCT in 3 US centers. Duration of followup was between 24 and 42 months posttransplant. Five patients achieved major responses but relapsed 3-22 months posttransplant. Two patients with relapse improved remarkably after restarting disease modifying antirheumatic drugs (DMARD). Two patients developed a mild RA flare at 3 and 5 months posttransplant and improved spontaneously. All 4 patients who improved after an initial disease flare remained highly functional at 14-22 months posttransplant. All patients in this study were anti-tumor necrosis factor (TNF) drug naive; all received a TNF blocker as a second line posttransplant salvage therapy, but only 3 responded. Future ASCT strategies need to focus on improving the durability of the early posttransplant responses.


Assuntos
Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Imunossupressores/uso terapêutico , Adulto , Artrite Reumatoide/etiologia , Artrite Reumatoide/imunologia , Etanercepte , Feminino , Seguimentos , Humanos , Imunoglobulina G/uso terapêutico , Masculino , Pessoa de Meia-Idade , Receptores do Fator de Necrose Tumoral/uso terapêutico , Recidiva , Transplante Autólogo , Resultado do Tratamento
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