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1.
Am Surg ; 88(6): 1224-1229, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33605784

RESUMO

BACKGROUND: Sleeve gastrectomy (SG) is the most frequently performed bariatric procedure in the world. Our purpose was to evaluate the percentage of excess weight loss (%EWL), resolution of obesity-related comorbidities after SG, and identify predictive factors of weight loss failure. METHODS: A prospective cohort study of adults who underwent SG during 2014 in 7 Belgian-French centers. Their demographic, preoperative, and postoperative data were prospectively collected and analyzed statistically. RESULTS: Overall, 529 patients underwent SG, with a mean preoperative weight and body mass index (BMI) of 118.9 ± 19.9 kg and 42.9 ± 5.5 kg/m2, respectively. Body mass index significantly decreased to 32.2 kg/m2 at 5 years (P < .001). The mean %EWL was 63.6% at 5 years. A significant reduction in dyslipidemia (28.0%-18.2%), obstructive sleep apnea (OSAS) (34.6%-25.1%), and arterial hypertension (HTN) (30.4%-21.5%) was observed after 5 years, but not for diabetes and gastroesophageal reflux disease (GERD). At multivariate analysis, age >50 years old, BMI >50 kg/m2, and previous laparoscopic adjustable gastric banding (LAGB) remained independent predictors of weight loss failure. CONCLUSIONS: Five years after SG, weight loss was satisfactory; the reduction of comorbidities was significant for dyslipidemia, OSAS, and HTN, but not diabetes and GERD. Age >50 years old, BMI >50 kg/m2, and previous LAGB were independent predictors of weight loss failure.


Assuntos
Refluxo Gastroesofágico , Hipertensão , Laparoscopia , Obesidade Mórbida , Apneia Obstrutiva do Sono , Adulto , Índice de Massa Corporal , Gastrectomia/métodos , Refluxo Gastroesofágico/cirurgia , Humanos , Laparoscopia/métodos , Pessoa de Meia-Idade , Obesidade Mórbida/complicações , Obesidade Mórbida/cirurgia , Estudos Prospectivos , Estudos Retrospectivos , Apneia Obstrutiva do Sono/cirurgia , Resultado do Tratamento , Redução de Peso
2.
Acta Chir Belg ; 121(6): 413-419, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33086992

RESUMO

INTRODUCTION: Laparoscopic sleeve gastrectomy (LSG) became the most frequently performed bariatric procedure worldwide, gaining rapidly popularity thanks to its technical simplicity and the relatively good results. The aim of this Belgian-French study was to evaluate postoperative complications, weight loss, and resolution of obesity-related comorbidities after LSG, and identify predictive factors of weight loss failure. PATIENTS AND METHODS: A prospective multicenter study was conducted on all LSG performed during 2014 in 7 centers. Their demographic, preoperative, and postoperative data were prospectively collected and analyzed statistically. RESULTS: Overall 529 patients underwent LSG, with a mean preoperative weight and body mass index (BMI) of 118.9 ± 19.9 kg and 42.9 ± 5.5 kg/m2, respectively. Postoperative mortality was null and early postoperative morbidity was 6%, including 2.5% of gastric leakage. BMI significantly decreased to 31.1 kg/m2 and 30.0 kg/m2 at 1 and 3 years, respectively (p < .001). The mean %EWL was 77.2 and 74.6% at 1 and 3 years. A significant reduction in dyslipidemia (28.0-16.8%), obstructive sleep apnea (OSAS) (34.6-23.3%) and arterial hypertension (HTN) (30.4-20.2%) was observed after 3 years, but it does not concern diabetes and gastroesophageal reflux disease (GERD). At multivariate analysis, age > 50 years old, BMI >50 kg/m2 and previous laparoscopic adjustable gastric banding (LAGB) remained independent predictors of weight loss failure. CONCLUSIONS: LSG for morbid obesity is safe and effective. Satisfactory outcome after 3 years can be achieved regarding %EWL and some comorbidities such as dyslipidemia, OSAS, and HTN, but not diabetes and GERD. Age > 50 years old, BMI > 50 kg/m2 and previous LAGB were independent predictors of weight loss failure.


Assuntos
Laparoscopia , Obesidade Mórbida , Bélgica/epidemiologia , Índice de Massa Corporal , Gastrectomia , Humanos , Pessoa de Meia-Idade , Obesidade Mórbida/cirurgia , Complicações Pós-Operatórias/epidemiologia , Estudos Prospectivos , Estudos Retrospectivos , Resultado do Tratamento , Redução de Peso
3.
Eur J Vasc Endovasc Surg ; 60(1): 16-25, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32184061

RESUMO

OBJECTIVE: A significant decrease in aneurysm related survival is observed at long term follow up after infrarenal endovascular aneurysm repair (EVAR) compared with open repair. Therefore, longer term results with new generation endografts are essential. The aim of this post-approval French multicentre prospective observational study (EPI-ANA-01) was to evaluate the technical success and five year mortality and secondary intervention rates of the third generation AnacondaTM endograft. METHODS: From June 2012 to October 2013, 176 consecutive unruptured infrarenal abdominal aortic aneurysms were included (160 male patients, mean age 75.3 ± 8.4 years). Survival, freedom from type Ia endoleak, limb events, and re-interventions were estimated using the Kaplan-Meier method. Anatomical and clinical characteristics were compared according to the occurrence of migration, conversion, adverse limb events, endoleak, and sac enlargement. RESULTS: The primary technical and clinical success rates were 98.3% and 94.9%, respectively. A hostile neck was identified in 33.9% of patients and 10.7% were treated outside instructions for use (IFU). An early post-operative (≤30 days) mortality rate of 1.7% was observed. At one and five years, respectively, the overall survival rate was 94.9% and 65.9% (aneurysm related in four patients [2.3%]) and the clinical success rate was 90.9% and 70.6%. Secondary interventions were performed in 35 of 176 patients (19.9%). The overall limb occlusion rate was 7.9% and the aneurysm sac diameter decreased significantly (pre-operative diameter 53.9 ± 8.6 mm vs. 42.3 ± 14.7 mm at five years; p < .001). Patients treated outside the instructions for use (IFU) had significantly higher rates of migration, surgical conversion, and aneurysm sac expansion (p = .03). CONCLUSION: The Anaconda endograft provides high technical success and satisfactory five year aneurysm exclusion and clinical success rates. However, implantation outside the IFU should be avoided, as it leads to significantly worse outcomes, and caution over the risk of limb occlusion and distal embolisation should be observed.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Procedimentos Endovasculares , Idoso , Aneurisma da Aorta Abdominal/mortalidade , Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/métodos , Implante de Prótese Vascular/mortalidade , Endoleak/epidemiologia , Endoleak/etiologia , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/métodos , Procedimentos Endovasculares/mortalidade , Feminino , França , Humanos , Masculino , Estudos Prospectivos , Sistema de Registros , Análise de Sobrevida , Resultado do Tratamento
4.
Chemistry ; 24(44): 11417-11425, 2018 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-29770508

RESUMO

A formal [4+1]-annulation strategy between sulfur ylides and 1,3-dienes was developed to afford functionalized cyclopentanoids. The process consists of a stereoselective cyclopropanation reaction followed, in situ, by a stereospecific MgI2 -catalyzed vinylcyclopropane-cyclopentene rearrangement. The use of chiral sulfur ylides provided cyclopentanoids with excellent enantiocontrol. A combined experimental and computational mechanistic study showed that the stereospecificity of the rearrangement could be accounted for by a double SN 2 reaction mechanism involving iodide.

5.
Polymers (Basel) ; 9(11)2017 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-30965895

RESUMO

The insertion of rigid monomers such as isosorbide into poly(ethylene terephthalate) (PET) allows for the access of polymers with improved properties, notably in terms of thermal stability. This biobased monomer is however poorly reactive, and harsh reaction conditions lead to color concerns regarding the resulting polymer. This has motivated the development of catalytic systems enabling an increase of the reaction rate and a good coloration. In this study, we have assessed bimetallic catalytic systems based on the main metals used for PET catalysis, i.e., antimony, germanium and titanium, for the synthesis of poly(ethylene terephthalate-co-isosorbide terephthalate) (PEIT). The Sb2O3/Ti(OiPr)4 combination leads to a high reaction rate while maintaining an acceptable coloration. On the other hand, combining Sb2O3 with GeO2 affords the formation of poly(ethylene terephthalate-co-isosorbide terephthalate) without coloration concerns and a reaction rate higher than that observed using the single metal catalysts. Molecular weights and microstructure including diethyleneglycol (DEG) and isosorbide contents are also discussed, together with the thermal properties of the resulting PEIT. The GeO2/Ti(OiPr)4 is also assessed, and leads to average performances.

6.
Chemistry ; 21(37): 12899-902, 2015 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-26235566

RESUMO

A highly enantioselective synthesis of functionalized cyclopentanoids by a formal asymmetric (4+1) annulation strategy was developed. The methodology consists of a stereoselective cyclopropanation reaction between chiral sulfur ylides and 1,3-dienes followed by a, in situ, stereospecific MgI2 -catalyzed rearrangement of vinylcyclopropanes. This method is distinguished by a remarkable compatibility with functional groups and a high stereocontrol.

7.
Chemistry ; 16(39): 11876-89, 2010 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-20839373

RESUMO

Synthesis of alternating pyridine-pyrrole molecular strands composed of two electron-rich pyrrole units (donors) sandwiched between three pyridinic cores (acceptors) is described. The envisioned strategy was a smooth electrosynthesis process involving ring contraction of corresponding tripyridyl-dipyridazine precursors. 2,6-Bis[6-(pyridazin-3-yl)]pyridine ligands 2a-c bearing pyridine residues at the terminal positions were prepared in suitable quantities by a Negishi metal cross-coupling procedure. The yields of heterocyclic coupling between 2-pyridyl zinc bromide reagents 12a-c and 2,6-bis(6-trifluoromethanesulfonylpyridazin-3-yl)pyridine increased from 68 to 95% following introduction of electron-donating methyl groups on the metallated halogenopyridine units. Favorable conditions for preparative electrochemical reduction of tripyridyl-dipyridazines 2b,c were established in THF/acetate buffer (pH 4.6)/acetonitrile to give the targeted 2,6-bis[5-(pyridin-2-yl)pyrrol-2-yl]pyridines 1b and 1c in good yields. The absorption behavior of the donor-acceptor tripyridyl-dipyrrole ligands was evaluated and compared to theoretical calculations. Highly fluorescent properties of these chromophores were found (ν(em)≈2 × 10(4) cm(-1) in MeOH and CH(2)Cl(2)), and both pyrrolic ligands exhibit a remarkable quantum yield in CH(2)Cl(2) (φ(f)=0.10). Structural studies in the solid state established the preferred cis conformation of the dipyrrolic ligands, which adopting a planar arrangement with an embedded molecule of water having a complexation energy exceeding 10 kcal mol(-1). The ability of the tripyridyl-dipyrrole to complex two copper(II) ions in a pentacoordinate square was investigated.


Assuntos
Antineoplásicos/síntese química , Cobre/química , Nitrogênio/química , Piridinas/síntese química , Pirróis/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Sítios de Ligação , Catálise , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Técnicas Eletroquímicas , Feminino , Humanos , Ligantes , Masculino , Modelos Químicos , Estrutura Molecular , Piridinas/química , Piridinas/farmacologia , Pirróis/química , Pirróis/farmacologia
8.
Org Lett ; 12(15): 3328-31, 2010 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-20597542

RESUMO

The [3 + 2] dipolar cycloaddition of 4-halosydnones with 1-haloalkynes opens a straightforward access to 3,5-dihalopyrazoles, valuable scaffolds for the elaboration of unsymmetrically 3,5-substituted pyrazole derivatives via site-selective Pd-catalyzed cross-coupling reactions. For instance, the flexible introduction of different (hetero)aryl substituents at the C-5 and C-3 positions of the PMP-protected pyrazole nucleus was achieved in a one-pot operation via sequential reactions with various boronic acids.


Assuntos
Alcinos/química , Ácidos Borônicos/química , Hidrocarbonetos Halogenados/química , Hidrocarbonetos Halogenados/síntese química , Paládio/química , Pirazóis/síntese química , Sidnonas/química , Catálise , Técnicas de Química Combinatória , Estrutura Molecular , Pirazóis/química
9.
PLoS One ; 3(7): e2543, 2008 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-18648536

RESUMO

The CXCL12gamma chemokine arises by alternative splicing from Cxcl12, an essential gene during development. This protein binds CXCR4 and displays an exceptional degree of conservation (99%) in mammals. CXCL12gamma is formed by a protein core shared by all CXCL12 isoforms, extended by a highly cationic carboxy-terminal (C-ter) domain that encompass four overlapped BBXB heparan sulfate (HS)-binding motifs. We hypothesize that this unusual domain could critically determine the biological properties of CXCL12gamma through its interaction to, and regulation by extracellular glycosaminoglycans (GAG) and HS in particular. By both RT-PCR and immunohistochemistry, we mapped the localization of CXCL12gamma both in mouse and human tissues, where it showed discrete differential expression. As an unprecedented feature among chemokines, the secreted CXCL12gamma strongly interacted with cell membrane GAG, thus remaining mostly adsorbed on the plasmatic membrane upon secretion. Affinity chromatography and surface plasmon resonance allowed us to determine for CXCL12gamma one of the higher affinity for HS (K(d) = 0.9 nM) ever reported for a protein. This property relies in the presence of four canonical HS-binding sites located at the C-ter domain but requires the collaboration of a HS-binding site located in the core of the protein. Interestingly, and despite reduced agonist potency on CXCR4, the sustained binding of CXCL12gamma to HS enabled it to promote in vivo intraperitoneal leukocyte accumulation and angiogenesis in matrigel plugs with much higher efficiency than CXCL12alpha. In good agreement, mutant CXCL12gamma chemokines selectively devoid of HS-binding capacity failed to promote in vivo significant cell recruitment. We conclude that CXCL12gamma features unique structural and functional properties among chemokines which rely on the presence of a distinctive C-ter domain. The unsurpassed capacity to bind to HS on the extracellular matrix would make CXCL12gamma the paradigm of haptotactic proteins, which regulate essential homeostatic functions by promoting directional migration and selective tissue homing of cells.


Assuntos
Quimiocina CXCL12/fisiologia , Fatores Quimiotáticos/química , Animais , Células CHO , Movimento Celular , Quimiocina CXCL12/química , Colágeno/química , Cricetinae , Cricetulus , Combinação de Medicamentos , Glicosaminoglicanos/metabolismo , Humanos , Cinética , Laminina/química , Camundongos , Ligação Proteica , Proteoglicanas/química , Receptores CXCR4/química , Ressonância de Plasmônio de Superfície
10.
J Gen Virol ; 88(Pt 9): 2605-2610, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17698673

RESUMO

A panel of 19 monoclonal antibodies (mAbs) was used to study the immunological variability of Lettuce mosaic virus (LMV), a member of the genus Potyvirus, and to perform a first epitope characterization of this virus. Based on their specificity of recognition against a panel of 15 LMV isolates, the mAbs could be clustered in seven reactivity groups. Surface plasmon resonance analysis indicated the presence, on the LMV particles, of at least five independent recognition/binding regions, correlating with the seven mAbs reactivity groups. The results demonstrate that LMV shows significant serological variability and shed light on the LMV epitope structure. The various mAbs should prove a new and efficient tool for LMV diagnostic and field epidemiology studies.


Assuntos
Anticorpos Monoclonais , Variação Genética , Lactuca/virologia , Vírus do Mosaico/genética , Vírus de Plantas/genética , Geografia , Vírus do Mosaico/classificação , Vírus do Mosaico/isolamento & purificação , Filogenia , Vírus de Plantas/classificação , Vírus de Plantas/isolamento & purificação , Ressonância de Plasmônio de Superfície/métodos
11.
AIDS Res Hum Retroviruses ; 22(7): 630-9, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16831087

RESUMO

HIV-1 Vpr is a 96-amino acid auxiliary protein that performs numerous activities during viral infection. In the present study, 10 antibodies were generated after mice immunization with either the N- or the C-terminus domain of Vpr, respectively, Vpr(1-51) and Vpr(52-96). ELISA and immunoblot experiments using pure synthetic overlapping Vpr peptides suggested that these anti-Vpr antibodies could be classified into five groups and that they recognized conformational or linear Vpr epitopes. Further analysis revealed the effect of C-terminal arginine mutations on the antibody binding. Two of the antibodies precipitated Vpr expressed after transfection of a Vpr-encoding vector in human cells. More importantly, one of them was able to detect Vpr in HIV-1-infected U1 cells and in HIV-1-infected human PBMC. Surface plasmon resonance experiments demonstrated that some of these antibodies prevented the interaction between Vpr and one of its cellular partners, the adenine nucleotide translocator. Thus, these anti-Vpr monoclonal antibodies may be useful to any laboratory working on the molecular mechanism of HIV-1 infection.


Assuntos
Anticorpos Monoclonais/biossíntese , Produtos do Gene vpr/imunologia , HIV-1/imunologia , Leucócitos Mononucleares/virologia , Animais , Anticorpos Monoclonais/imunologia , Mapeamento de Epitopos/métodos , Feminino , Humanos , Imunoprecipitação/métodos , Camundongos , Camundongos Endogâmicos BALB C , Ressonância de Plasmônio de Superfície , Produtos do Gene vpr do Vírus da Imunodeficiência Humana
12.
Cell ; 121(3): 335-48, 2005 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-15882617

RESUMO

Fibroblasts often constitute the majority of the stromal cells within a breast carcinoma, yet the functional contributions of these cells to tumorigenesis are poorly understood. Using a coimplantation tumor xenograft model, we demonstrate that carcinoma-associated fibroblasts (CAFs) extracted from human breast carcinomas promote the growth of admixed breast carcinoma cells significantly more than do normal mammary fibroblasts derived from the same patients. The CAFs, which exhibit the traits of myofibroblasts, play a central role in promoting the growth of tumor cells through their ability to secrete stromal cell-derived factor 1 (SDF-1); CAFs promote angiogenesis by recruiting endothelial progenitor cells (EPCs) into carcinomas, an effect mediated in part by SDF-1. CAF-secreted SDF-1 also stimulates tumor growth directly, acting through the cognate receptor, CXCR4, which is expressed by carcinoma cells. Our findings indicate that fibroblasts within invasive breast carcinomas contribute to tumor promotion in large part through the secretion of SDF-1.


Assuntos
Carcinoma Ductal de Mama/patologia , Quimiocinas CXC/metabolismo , Fibroblastos/metabolismo , Neovascularização Patológica/patologia , Células Estromais/metabolismo , Actinas/metabolismo , Animais , Carcinoma Ductal de Mama/metabolismo , Comunicação Celular , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células , Separação Celular , Quimiocina CXCL12 , Quimiocinas CXC/genética , Quimiotaxia/fisiologia , Células Endoteliais/patologia , Feminino , Fibroblastos/patologia , Fibroblastos/transplante , Expressão Gênica/genética , Humanos , Camundongos , Camundongos Nus , Modelos Biológicos , Neovascularização Patológica/metabolismo , Comunicação Parácrina/fisiologia , Receptores CXCR4/antagonistas & inibidores , Receptores CXCR4/genética , Células-Tronco/patologia , Células Estromais/patologia , Células Estromais/transplante , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Biochemistry ; 43(46): 14555-65, 2004 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-15544326

RESUMO

The conformational preferences of a 22-amino acid peptide (LIDRLIERAEDpSGNEpSEGEISA) that mimics the phosphorylated HIV-1-encoded virus protein U (Vpu) antigen have been investigated by NMR spectroscopy. Degradation of HIV receptor CD4 by the proteasome, mediated by the HIV-1 protein Vpu, is crucial for the release of fully infectious virions. Phosphorylation of Vpu at sites Ser52 and Ser56 on the DSGXXS motif is required for the interaction of Vpu with the ubiquitin ligase SCF(beta)(-TrCP) which triggers CD4 degradation by the proteasome. This motif is conserved in several signaling proteins known to be degraded by the proteasome. The interaction of the P-Vpu(41-62) peptide with its monoclonal antibody has been studied by transferred nuclear Overhauser effect NMR spectroscopy (TRNOESY) and saturation transfer difference NMR (STD NMR) spectroscopy. The peptide was found to adopt a bend conformation upon binding to the antibody; the peptide residues (Asp51-pSer56) forming this bend are recognized by the antibody as demonstrated by STD NMR experiments. The three-dimensional structure of P-Vpu(41-62) in the bound conformation was determined by TRNOESY spectra; the peptide adopts a compact structure in the presence of mAb with formation of several bends around Leu45 and Ile46 and around Ile60 and Ser61, with a tight bend created by the DpS(52)GNEpS(56) motif. STD NMR studies provide evidence for the existence of a conformational epitope containing tandem repeats of phosphoserine motifs. The peptide's epitope is predominantly located in the large bend and in the N-terminal segment, implicating bidentale association. These findings are in excellent agreement with a recently published NMR structure required for the interaction of Vpu with the SCF(beta)(-TrCP) protein.


Assuntos
Anticorpos Monoclonais/metabolismo , Sítios de Ligação de Anticorpos , Mapeamento de Epitopos , HIV-1 , Fragmentos de Peptídeos/metabolismo , Proteínas Virais Reguladoras e Acessórias/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Mapeamento de Epitopos/métodos , Proteínas do Vírus da Imunodeficiência Humana , Modelos Moleculares , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular/métodos , Fragmentos de Peptídeos/imunologia , Fosforilação , Ligação Proteica , Conformação Proteica , Proteínas Virais Reguladoras e Acessórias/química , Proteínas Virais Reguladoras e Acessórias/imunologia
14.
Immunity ; 17(5): 653-64, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12433371

RESUMO

Cytomegalovirus (CMV) infection is characterized by host immunosuppression and multiorganic involvement. CMV-infected dendritic cells (DC) were recently shown to display reduced immune functions, but their role in virus dissemination is not clear. In this report, we demonstrated that CMV could be captured by DC through binding on DC-SIGN and subsequently transmitted to permissive cells. Moreover, blocking DC-SIGN by specific antibodies inhibited DC infection by primary CMV isolates and expression of DC-SIGN or its homolog DC-SIGNR rendered susceptible cells permissive to CMV infection. We demonstrated that CMV envelope glycoprotein B is a viral ligand for DC-SIGN and DC-SIGNR. These results provide new insights into the molecular interactions contributing to cell infection by CMV and extend DC-SIGN implication in virus propagation.


Assuntos
Moléculas de Adesão Celular/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Células Dendríticas/virologia , Lectinas Tipo C/imunologia , Receptores de Superfície Celular/imunologia , Moléculas de Adesão Celular/metabolismo , Citomegalovirus/metabolismo , Infecções por Citomegalovirus/metabolismo , Infecções por Citomegalovirus/virologia , Células Dendríticas/imunologia , Células HeLa , Humanos , Lectinas Tipo C/metabolismo , Ligantes , Receptores de Superfície Celular/metabolismo , Proteínas do Envelope Viral/imunologia , Proteínas do Envelope Viral/metabolismo , Replicação Viral/imunologia
15.
J Gen Virol ; 83(Pt 7): 1765-1770, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12075097

RESUMO

Monoclonal antibodies were raised against helper component-proteinase (HcPro) purified from plants infected with the potyvirus Lettuce mosaic virus (LMV). These antibodies were used in a two-site triple antibody sandwich ELISA assay together with polyclonal antibodies directed against purified virions. An interaction between HcPro and the viral coat protein (CP) was demonstrated in extracts of LMV-infected leaves, as well as for two other potyviruses, Plum pox virus and Potato virus Y. The CP-HcPro interaction was not abolished in LMV derivatives with an HcPro GFP N-terminal fusion, or with a deletion from the CP of the amino acids involved in aphid transmission. Electron microscopy indicated that HcPro probably does not interact with the CP in the form of assembled virions or virus-like particles. Together, these results suggest that the interaction detected between CP and HcPro might be involved in a process of the potyvirus cycle different from aphid transmission.


Assuntos
Capsídeo/metabolismo , Cisteína Endopeptidases/metabolismo , Lactuca/metabolismo , Potyvirus/metabolismo , Proteínas Virais/metabolismo , Capsídeo/genética , Cisteína Endopeptidases/genética , Deleção de Genes , Proteínas de Fluorescência Verde , Lactuca/virologia , Proteínas Luminescentes , Doenças das Plantas/virologia , Ligação Proteica , Sequências Repetidas Terminais , Proteínas Virais/genética
16.
J Biol Chem ; 277(18): 15677-89, 2002 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-11867624

RESUMO

Activation of CXCR4 by the CXC chemokine stromal cell-derived factor-1 (SDF-1) requires interaction of the amino-terminal domains of both molecules. We report that proteinases released from either mononucleated blood cells or polymorphonuclear neutrophils degranulated by inflammatory stimuli generate an SDF-1 fragment that is deleted from amino-terminal residues Lys(1)-Pro(2)-Val(3), as characterized by mass spectrometry analysis. The proteolyzed chemokine fails to induce agonistic functions and is unable to prevent the fusogenic capacity of CXCR4-tropic human immunodeficiency viruses. Furthermore, we observed that exposure of CXCR4-expressing cells to leukocyte proteinases results in the proteolysis of the extracellular amino-terminal domain of the receptor, as assessed by flow cytometry analysis and electrophoretic separation of immunoprecipitated CXCR4. Blockade of SDF-1 and CXCR4 proteolysis by the specific leukocyte elastase inhibitor, N-methoxysuccinyl-alanine-alanine-proline-valine-chloromethyl ketone, identified elastase as the major enzyme among leukocyte-secreted proteinases that accounts for inactivation of both SDF-1 and CXCR4. Indeed, purified leukocyte elastase generated in either SDF-1 or CXCR4 a pattern of cleavage indistinguishable from that observed with leukocyte-secreted proteinases. Our findings suggest that elastase-mediated proteolysis of SDF-1/CXCR4 is part of a mechanism regulating their biological functions in both homeostatic and pathologic processes.


Assuntos
Quimiocinas CXC/metabolismo , Elastase de Leucócito/metabolismo , Receptores CXCR4/metabolismo , Animais , Anticorpos Monoclonais/farmacologia , Sítios de Ligação , Cálcio/metabolismo , Fusão Celular , Quimiocina CXCL12 , Quimiocinas CXC/farmacologia , Citosol/metabolismo , HIV-1/fisiologia , Humanos , Células Jurkat , Leucócitos Mononucleares/enzimologia , Leucócitos Mononucleares/fisiologia , Camundongos , Oligopeptídeos/metabolismo , Oligopeptídeos/farmacologia , Deleção de Sequência , Espectrometria de Massas por Ionização por Electrospray , Células Estromais/metabolismo , Especificidade por Substrato
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