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1.
Mol Ther ; 32(4): 1061-1079, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38382529

RESUMO

Complement-mediated diseases can be treated using systemic inhibitors. However, complement components are abundant in circulation, affecting systemic inhibitors' exposure and efficacy. Furthermore, because of complement's essential role in immunity, systemic treatments raise infection risk in patients. To address these challenges, we developed antibody fusion proteins combining the alternative-pathway complement inhibitor factor H (fH1-5) with an anti-C3d monoclonal antibody (C3d-mAb-2fH). Because C3d is deposited at sites of complement activity, this molecule localizes to tissue complement while minimizing circulating complement engagement. These fusion proteins bind to deposited complement in diseased human skin sections and localize to activated complement in a primate skin injury model. We further explored the pharmacology of C3d-mAb-2fH proteins in rodent models with robust tissue complement activation. Doses of C3d-mAb-2fH >1 mg/kg achieved >75% tissue complement inhibition in mouse and rat injury models while avoiding circulating complement blockade. Glomerular-specific complement inhibition reduced proteinuria and preserved podocyte foot-process architecture in rat membranous nephropathy, indicating disease-modifying efficacy. These data indicate that targeting local tissue complement results in durable and efficacious complement blockade in skin and kidney while avoiding systemic inhibition, suggesting broad applicability of this approach in treating a range of complement-mediated diseases.


Assuntos
Fator H do Complemento , Nefropatias , Humanos , Camundongos , Ratos , Animais , Fator H do Complemento/genética , Complemento C3d/metabolismo , Nefropatias/etiologia , Anticorpos , Ativação do Complemento
2.
BMJ Qual Saf ; 2022 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-35552253

RESUMO

BACKGROUND: Documenting an indication when prescribing antimicrobials is considered best practice; however, a better understanding of the evidence is needed to support broader implementation of this practice. OBJECTIVES: We performed a scoping review to evaluate antimicrobial indication documentation as it pertains to its implementation, prevalence, accuracy and impact on clinical and utilisation outcomes in all patient populations. ELIGIBILITY CRITERIA: Published and unpublished literature evaluating the documentation of an indication for antimicrobial prescribing. SOURCES OF EVIDENCE: A search was conducted in MEDLINE, Embase, CINAHL and International Pharmaceutical Abstracts in addition to a review of the grey literature. CHARTING AND ANALYSIS: Screening and extraction was performed by two independent reviewers. Studies were categorised inductively and results were presented descriptively. RESULTS: We identified 123 peer-reviewed articles and grey literature documents for inclusion. Most studies took place in a hospital setting (109, 89%). The median prevalence of antimicrobial indication documentation was 75% (range 4%-100%). Studies evaluating the impact of indication documentation on prescribing and patient outcomes most commonly examined appropriateness and identified a benefit to prescribing or patient outcomes in 17 of 19 studies. Qualitative studies evaluating healthcare worker perspectives (n=10) noted the common barriers and facilitators to this practice. CONCLUSION: There is growing interest in the importance of documenting an indication when prescribing antimicrobials. While antimicrobial indication documentation is not uniformly implemented, several studies have shown that multipronged approaches can be used to improve this practice. Emerging evidence demonstrates that antimicrobial indication documentation is associated with improved prescribing and patient outcomes both in community and hospital settings. But setting-specific and larger trials are needed to provide a more robust evidence base for this practice.

3.
Chembiochem ; 22(12): 2107-2110, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-33838082

RESUMO

PARP14 is an interferon-stimulated gene that is overexpressed in multiple tumor types, influencing pro-tumor macrophage polarization as well as suppressing the antitumor inflammation response by modulating IFN-γ and IL-4 signaling. PARP14 is a 203 kDa protein that possesses a catalytic domain responsible for the transfer of mono-ADP-ribose to its substrates. PARP14 also contains three macrodomains and a WWE domain which are binding modules for mono-ADP-ribose and poly-ADP-ribose, respectively, in addition to two RNA recognition motifs. Catalytic inhibitors of PARP14 have been shown to reverse IL-4 driven pro-tumor gene expression in macrophages, however it is not clear what roles the non-enzymatic biomolecular recognition motifs play in PARP14-driven immunology and inflammation. To further understand this, we have discovered a heterobifunctional small molecule designed based on a catalytic inhibitor of PARP14 that binds in the enzyme's NAD+ -binding site and recruits cereblon to ubiquitinate it and selectively target it for degradation.


Assuntos
Poli(ADP-Ribose) Polimerases/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Estrutura Molecular , Bibliotecas de Moléculas Pequenas/síntese química , Bibliotecas de Moléculas Pequenas/química
4.
Cell Chem Biol ; 28(8): 1158-1168.e13, 2021 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-33705687

RESUMO

PARP14 has been implicated by genetic knockout studies to promote protumor macrophage polarization and suppress the antitumor inflammatory response due to its role in modulating interleukin-4 (IL-4) and interferon-γ signaling pathways. Here, we describe structure-based design efforts leading to the discovery of a potent and highly selective PARP14 chemical probe. RBN012759 inhibits PARP14 with a biochemical half-maximal inhibitory concentration of 0.003 µM, exhibits >300-fold selectivity over all PARP family members, and its profile enables further study of PARP14 biology and disease association both in vitro and in vivo. Inhibition of PARP14 with RBN012759 reverses IL-4-driven protumor gene expression in macrophages and induces an inflammatory mRNA signature similar to that induced by immune checkpoint inhibitor therapy in primary human tumor explants. These data support an immune suppressive role of PARP14 in tumors and suggest potential utility of PARP14 inhibitors in the treatment of cancer.


Assuntos
Antineoplásicos/farmacologia , Inflamação/tratamento farmacológico , Interleucina-4/antagonistas & inibidores , Neoplasias Renais/tratamento farmacológico , Macrófagos/efeitos dos fármacos , Poli(ADP-Ribose) Polimerases/metabolismo , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Relação Dose-Resposta a Droga , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Células HEK293 , Humanos , Inflamação/genética , Inflamação/metabolismo , Interleucina-4/genética , Neoplasias Renais/genética , Neoplasias Renais/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Estrutura Molecular , Poli(ADP-Ribose) Polimerases/genética , Células RAW 264.7 , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
5.
Artigo em Inglês | MEDLINE | ID: mdl-30646551

RESUMO

Doxing is a form of cyberbullying in which personal information on others is sought and released, thereby violating their privacy and facilitating further harassment. This study examined adolescents' doxing participation using a representative sample of 2120 Hong Kong secondary school students. Just over one in 10 had engaged in doxing, and doxing behavior significantly increased the probability of disclosing personal information on others (odds ratio ranged between 2.705 and 5.181). Social and hostile doxing were the two most common forms of doxing. Girls were significantly more likely to conduct social doxing (χ² = 11.84, p < 0.001), where their target was to obtain social information (χ² = 4.79, p = 0.029), whereas boys were more likely to engage in hostile doxing aimed at obtaining personally identifiable information (χ² = 4.31, p = 0.038) and information on others' current living situations (χ² = 4.17, p = 0.041). Students who had perpetrated doxing acts were more likely to have experienced information disclosure as victims, perpetrators, or bystanders. Future studies should examine doxing's impacts and its relationship with other forms of cyberbullying and traditional bullying. Because doxing may lead to on- and off-line harassment, family, adolescents, schools, and communities must work together to develop effective approaches for combating it.


Assuntos
Comportamento do Adolescente , Bullying/psicologia , Internet , Adolescente , Vítimas de Crime , Revelação , Feminino , Hong Kong , Hostilidade , Humanos , Intenção , Masculino , Privacidade , Instituições Acadêmicas , Estudantes
6.
Artigo em Inglês | MEDLINE | ID: mdl-30486402

RESUMO

Doxing is the searching for and intentional disclosure of private information about a particular individual on the Internet without his or her consent, and is often used to exact punishment. The aim of this study was to investigate the associations between doxing victimization and emotional problems in secondary school students, paying particular regard to the impacts of different types of doxed information, the relationship between the perpetrators and victims of doxing, and the nature of the online platforms where doxing occurs. A sample of 2120 Hong Kong secondary school students of differing socioeconomic backgrounds participated in the study. The results show that almost all types of disclosed personal information result in negative feelings in victims, including depression, anxiety, and stress. Girls were also found to be more likely than boys to be doxed. Significant associations were found between emotional problems and the disclosure of mobile phone numbers and personal photos and videos; doxing conducted by schoolmates and anxiety and depression, and doxing through Instant Messenger and anxiety. Further exploration of integrated cyber violence prevention programs and research on the details of doxing are recommended.


Assuntos
Comportamento do Adolescente/psicologia , Bullying/psicologia , Vítimas de Crime/psicologia , Internet , Estresse Psicológico , Estudantes/psicologia , Adolescente , Bullying/estatística & dados numéricos , Vítimas de Crime/estatística & dados numéricos , Feminino , Hong Kong , Humanos , Masculino , Estudantes/estatística & dados numéricos
7.
Fluids Barriers CNS ; 15(1): 10, 2018 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-29558954

RESUMO

BACKGROUND: Many studies have focused on the challenges of small molecule uptake across the blood-brain barrier, whereas few in-depth studies have assessed the challenges with the uptake of antibodies into the central nervous system (CNS). In drug development, cerebrospinal fluid (CSF) sampling is routinely used as a surrogate for assessing CNS drug exposure and biomarker levels. In this report, we have studied the kinetic correlation between CSF and serum drug concentration-time profiles for five humanized monoclonal antibodies in rats and cynomolgus monkeys and analyzed factors that affect their CSF exposure. RESULTS: Upon intravenous (IV) bolus injection, antibodies entered the CNS slowly and reached maximum CSF concentration ( CSF T max ) in one to several days in both rats and monkeys. Antibody serum and CSF concentration-time curves converged until they became parallel after CSF T max was reached. Antibody half-lives in CSF ( CSF t ½ ) approximated their serum half-lives ( serum t ½ ). Although the intended targets of these antibodies were different, the steady-state CSF to serum concentration ratios were similar at 0.1-0.2% in both species. Independent of antibody target and serum concentration, CSF-to-serum concentration ratios for individual monkeys ranged by up to tenfold from 0.03 to 0.3%. CONCLUSION: Upon systemic administration, average antibodies CSF-to-serum concentration ratios in rats and monkeys were 0.1-0.2%. The CSF t ½ of the antibodies was largely determined by their long systemic t ½ ( systemic t ½ ).


Assuntos
Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/líquido cefalorraquidiano , Administração Intravesical , Animais , Anticorpos Monoclonais/sangue , Encéfalo/metabolismo , Líquido Cefalorraquidiano/metabolismo , Humanos , Cinética , Macaca fascicularis , Masculino , Ratos Sprague-Dawley , Medula Espinal/metabolismo , Fatores de Tempo
8.
Child Abuse Negl ; 77: 180-187, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29407606

RESUMO

The sustained increase in their use of social networking facilitates the development of adolescents but comes with the risk of cyberbullying, which creates new challenges in regard to adolescent protection. Past evidence shows that family victimization may play an essential role in the way adolescents learn cyberbullying behaviors. Yet, research on the co-occurrence of family victimization and cyberbullying is limited. This study aims to investigate the associations between cyberbullying and family victimization among adolescents, and to examine the health correlates of cyberbullying and family poly-victimization. A large sample of 18,341 students, aged 15-17, from six cities in China, collected between 2009 and 2010 is employed in the present study, which investigated the association between various kinds of family victimization and adolescent cyberbullying. Data analysis was conducted in 2017. In-law conflict, intimate partner violence, elder abuse and neglect, and child maltreatment were associated with a higher possibility of children becoming internet victims. Parents' divorce and separation, low family income, mother's low level of education, and father's unemployment were all associated with cyberbullying victimization. Cyber victimization was positively correlated to symptoms of PTSD and depression, self-harm, and other physical and mental health variables. Possible explanations for the relationships found in this study are discussed and implications for future research and services are provided. Proactive screening for family poly-victimization and cyberbullying is suggested. Schools are highly recommended to cooperate with parents to promote cyber safety.


Assuntos
Vítimas de Crime/psicologia , Cyberbullying/psicologia , Adolescente , Comportamento do Adolescente/psicologia , Idoso , Maus-Tratos Infantis/psicologia , Maus-Tratos Infantis/estatística & dados numéricos , China/epidemiologia , Vítimas de Crime/estatística & dados numéricos , Cyberbullying/estatística & dados numéricos , Depressão/epidemiologia , Depressão/psicologia , Abuso de Idosos/psicologia , Abuso de Idosos/estatística & dados numéricos , Família , Feminino , Humanos , Internet , Masculino , Saúde Mental , Instituições Acadêmicas , Comportamento Autodestrutivo/epidemiologia , Comportamento Autodestrutivo/psicologia , Estudantes/psicologia
10.
Am J Pathol ; 187(6): 1399-1412, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28408124

RESUMO

The clinical progression of Alzheimer disease (AD) is associated with the accumulation of tau neurofibrillary tangles, which may spread throughout the cortex by interneuronal tau transfer. If so, targeting extracellular tau species may slow the spreading of tau pathology and possibly cognitive decline. To identify suitable target epitopes, we tested the effects of a panel of tau antibodies on neuronal uptake and aggregation in vitro. Immunodepletion was performed on brain extract from tau-transgenic mice and postmortem AD brain and added to a sensitive fluorescence resonance energy transfer-based tau uptake assay to assess blocking efficacy. The antibodies reduced tau uptake in an epitope-dependent manner: N-terminal (Tau13) and middomain (6C5 and HT7) antibodies successfully prevented uptake of tau species, whereas the distal C-terminal-specific antibody (Tau46) had little effect. Phosphorylation-dependent (40E8 and p396) and C-terminal half (4E4) tau antibodies also reduced tau uptake despite removing less total tau by immunodepletion, suggesting specific interactions with species involved in uptake. Among the seven antibodies evaluated, 6C5 most efficiently blocked uptake and subsequent aggregation. More important, 6C5 also blocked neuron-to-neuron spreading of tau in a unique three-chamber microfluidic device. Furthermore, 6C5 slowed down the progression of tau aggregation even after uptake had begun. Our results imply that not all antibodies/epitopes are equally robust in terms of blocking tau uptake of human AD-derived tau species.


Assuntos
Doença de Alzheimer/metabolismo , Neurônios/metabolismo , Proteínas tau/metabolismo , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Animais , Anticorpos Monoclonais/biossíntese , Anticorpos Monoclonais/imunologia , Encéfalo/metabolismo , Encéfalo/patologia , Células Cultivadas , Epitopos/imunologia , Feminino , Humanos , Interneurônios/metabolismo , Masculino , Camundongos Transgênicos , Técnicas Analíticas Microfluídicas , Terapia de Alvo Molecular/métodos , Emaranhados Neurofibrilares/metabolismo , Emaranhados Neurofibrilares/patologia , Fosforilação , Proteínas tau/antagonistas & inibidores , Proteínas tau/imunologia
11.
MAbs ; 7(4): 681-92, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25879139

RESUMO

Polyomavirus JC (JCV) is the causative agent of progressive multifocal leukoencephalopathy (PML), a rare and frequently fatal brain disease that afflicts a small fraction of the immune-compromised population, including those affected by AIDS and transplantation recipients on immunosuppressive drug therapy. Currently there is no specific therapy for PML. The major capsid viral protein 1 (VP1) involved in binding to sialic acid cell receptors is believed to be a key player in pathogenesis. PML-specific mutations in JCV VP1 sequences present at the binding pocket of sialic acid cell receptors, such as L55F and S269F, abolish sialic acid recognition and might favor PML onset. Early diagnosis of these PML-specific mutations may help identify patients at high risk of PML, thus reducing the risks associated with immunosuppressive therapy. As a first step in the development of such early diagnostic tools, we report identification and characterization of affinity reagents that specifically recognize PML-specific mutations in VP1 variants using phage display technology. We first identified 2 peptides targeting wild type VP1 with moderate specificity. Fine-tuning via selection of biased libraries designed based on 2 parental peptides yielded peptides with different, yet still moderate, bindinspecificities. In contrast, we had great success in identifying synthetic antibodies that recognize one of the PML-specific mutations (L55F) with high specificity from the phage-displayed libraries. These peptides and synthetic antibodies represent potential candidates for developing tailored immune-based assays for PML risk stratification in addition to complementing affinity reagents currently available for the study of PML and JCV.


Assuntos
Proteínas do Capsídeo/imunologia , Vírus JC/imunologia , Leucoencefalopatia Multifocal Progressiva/imunologia , Mutação , Peptídeos/imunologia , Anticorpos de Cadeia Única/imunologia , Proteínas do Capsídeo/genética , Humanos , Vírus JC/genética , Leucoencefalopatia Multifocal Progressiva/genética , Peptídeos/genética , Anticorpos de Cadeia Única/genética
12.
Eur J Cancer ; 47(11): 1736-46, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21458984

RESUMO

BIIB015 is an immunoconjugate created for the treatment of solid tumours and is currently in Phase I of clinical evaluation. BIIB015 consists of a humanised monoclonal antibody against the Cripto protein carrying a payload, via a hindered disulphide linker, of the maytansinoid derivative, DM4. Cripto is a GPI-linked protein required for signal transduction of the TGF-beta ligand, Nodal. Cripto has been previously described as an oncogene and fits the classic pattern of an embryonic gene that is re-expressed in a transformed tumour cell. Cripto expression is highly prevalent on a number of solid tumours, including greater than 75% of breast, lung, and colorectal tumours. Our report documents for the first time that targeting the cell surface Cripto protein with an anti-Cripto antibody-cytotoxic conjugate is an effective means of inhibiting or regressing growth of Cripto positive tumours. BIIB015 which utilises a 'cleavable' linker containing a disulphide bond exhibits superior activity when compared to huB3F6 mAb conjugates with different linker systems, including one with a 'non-cleavable' linker. BIIB015 displays specificity for Cripto in both in vitro and in vivo experiments. In human xenograft models originating from lung (Calu-6), colon (CT-3), testicular (NCCIT) and breast (MDA-MB-231) tumour samples, BIIB015 shows robust activity with results ranging from >50% tumour inhibition to complete tumour regression. The efficacy seen in the MDA-MB-231 model, a triple negative (-HER2, -ER, and -PR) tumour, is particularly exciting since there is currently no approved therapy for this indication. In addition, BIIB015 can be combined with standard of care chemotherapeutics for enhanced efficacy.


Assuntos
Anticorpos Monoclonais/farmacologia , Anticorpos/química , Antineoplásicos/farmacologia , Regulação Neoplásica da Expressão Gênica , Imunoconjugados/farmacologia , Neoplasias/metabolismo , Animais , Linhagem Celular Tumoral , Sobrevivência Celular , Feminino , Proteínas Ligadas por GPI/metabolismo , Humanos , Imuno-Histoquímica/métodos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Masculino , Camundongos , Camundongos SCID , Modelos Químicos , Proteínas de Neoplasias/metabolismo , Transplante de Neoplasias
13.
Br J Nutr ; 105(2): 282-6, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20854699

RESUMO

Ageing women may choose to drink soya milk to reduce menopausal symptoms. As fermentation enriches soya milk with isoflavone aglycones, its beneficial qualities may improve. To reduce osteoporotic risk, however, soya milk must be Ca enriched, and it is not known how fermentation affects Ca bioavailability. A randomised crossover pilot study was undertaken to compare the Ca absorption of fortified soya milk with that of fermented and fortified soya milk in twelve Australian osteopenic post-menopausal women. The fortified soya milk was inoculated with Lactobacillus acidophilus American Type Culture Collection (ATCC) 4962 and fermented for 24 h at 37°C. Ca absorption from soya milk samples was measured using a single isotope radiocalcium method. Participants had a mean age of 54·8 (sd 12·3) years, with mean BMI of 26·5 (sd 5·5) kg/m2 and subnormal to normal serum 25-hydroxyvitamin D (mean 62·5 (sd 19·1) nmol/l). Participants consumed 185 kBq of 45Ca in 44 mg of Ca carrier. The mean fractional Ca absorption (α) from soya milk and fermented soya milk was 0·64 (sd 0·23) and 0·71 (sd 0·29), respectively, a difference not of statistical significance (P = 0·122). Although fermentation of soya milk may provide other health benefits, fermentation had little effect on acute Ca absorption.


Assuntos
Doenças Ósseas Metabólicas/dietoterapia , Cálcio da Dieta/administração & dosagem , Cálcio da Dieta/farmacocinética , Absorção Intestinal , Leite de Soja/administração & dosagem , Idoso , Disponibilidade Biológica , Doenças Ósseas Metabólicas/fisiopatologia , Estudos Cross-Over , Feminino , Fermentação , Alimentos Fortificados , Humanos , Lactobacillus acidophilus , Pessoa de Meia-Idade , Projetos Piloto , Pós-Menopausa , Probióticos , Leite de Soja/química
14.
Ann Neurol ; 68(3): 295-303, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20737510

RESUMO

OBJECTIVE: A study was undertaken to establish an enzyme-linked immunosorbent assay (ELISA) to detect JC virus (JCV)-specific antibodies in multiple sclerosis (MS) patients, and to evaluate its potential utility for identifying patients at higher or lower risk (ie, risk stratification) of developing progressive multifocal leukoencephalopathy (PML). METHODS: A 2-step assay for detecting and confirming the presence of anti-JCV antibodies in human serum and plasma was developed and demonstrated to be both sensitive and specific. ELISA cutpoints were statistically established using sera from >800 MS patients from natalizumab clinical studies. Subsequently, this assay was used to determine the presence of anti-JCV antibodies in natalizumab-treated PML patients where serum samples were collected 16-180 months prior to the diagnosis of PML. RESULTS: In our evaluation of natalizumab-treated MS patients, 53.6% tested positive for anti-JCV antibodies, with a 95% confidence interval of 49.9 to 57.3%. The false-negative rate of the ELISA was calculated to be approximately 2.5%, with an upper 1-sided confidence limit of 4.4%. Notably, we observed anti-JCV antibodies in all 17 available pre-PML sera samples, which was significantly different from the 53.6% seropositivity observed in the overall MS study population (p < 0.0001). INTERPRETATION: This 2-step assay provides a means to classify MS patients as having detectable or not detectable levels of anti-JCV antibodies. The finding that all 17 of the pre-PML samples that were available tested seropositive, and none tested seronegative, warrants further research on the clinical utility of the anti-JCV antibody assay as a potential tool for stratifying MS patients for higher or lower risk of developing PML.


Assuntos
Anticorpos Anti-Idiotípicos/uso terapêutico , Vírus JC/imunologia , Leucoencefalopatia Multifocal Progressiva , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados , DNA Viral/imunologia , Ensaio de Imunoadsorção Enzimática , Humanos , Leucoencefalopatia Multifocal Progressiva/diagnóstico , Leucoencefalopatia Multifocal Progressiva/imunologia , Leucoencefalopatia Multifocal Progressiva/terapia , Natalizumab , Fatores de Risco , Carga Viral/métodos
15.
J Med Chem ; 53(11): 4522-30, 2010 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-20462258

RESUMO

A series of saligenin beta(2) adrenoceptor agonist antedrugs having high clearance were prepared by reacting a protected saligenin oxazolidinone with protected hydroxyethoxyalkoxyalkyl bromides, followed by removal of the hydroxy-protecting group, alkylation, and final deprotection. The compounds were screened for beta(2), beta(1), and beta(3) agonist activity in CHO cells. The onset and duration of action in vitro of selected compounds were assessed on isolated superfused guinea pig trachea. Compound 13f had high potency, selectivity, fast onset, and long duration of action in vitro and was found to have long duration in vivo, low oral bioavailability in the rat, and to be rapidly metabolized. Crystalline salts of 13f (vilanterol) were identified that had suitable properties for inhaled administration. A proposed binding mode for 13f to the beta(2)-receptor is presented.


Assuntos
Agonistas de Receptores Adrenérgicos beta 2 , Agonistas Adrenérgicos beta/química , Agonistas Adrenérgicos beta/farmacologia , Agonistas Adrenérgicos beta/síntese química , Agonistas Adrenérgicos beta/metabolismo , Animais , Álcool Benzílico/química , Álcoois Benzílicos/síntese química , Álcoois Benzílicos/química , Álcoois Benzílicos/metabolismo , Álcoois Benzílicos/farmacologia , Células CHO , Clorobenzenos/síntese química , Clorobenzenos/química , Clorobenzenos/metabolismo , Clorobenzenos/farmacologia , Cricetinae , Cricetulus , Humanos , Modelos Moleculares , Conformação Proteica , Ratos , Receptores Adrenérgicos beta 2/química , Relação Estrutura-Atividade
16.
Cancer Biol Ther ; 9(6): 437-45, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-20061819

RESUMO

Integrin alpha6beta4 signaling interactions have been implicated in tumor progression, and beta4 expression has been linked to poor prognosis in certain breast cancer subtypes. We generated human antibodies to alpha6beta4 to further evaluate its role in tumor cell signaling. Biochemical characterization indicated these antibodies are specific for alpha6beta4, recognize distinct epitopes and have low nanomolar affinities for both human and murine protein. The antibodies demonstrated differing effects on alpha6beta4-mediated cellular adhesion, highlighting the existence of different functional epitopes on alpha6beta4. Interestingly however both antibodies blocked adhesion-independent growth in a panel of breast cancer cell lines. Antibody induced apoptosis and inhibition of phosphoinositide 3-kinase (PI3K) signaling were also observed within the context of matrix adhesion. Enhanced inhibitory effects were observed when the alpha6beta4 antibodies were used in combination with antibodies to epidermal growth factor receptor (EGFR) or erythoblastic leukemia viral oncogene homolog 2 (ErbB2). These findings illustrate a role for both the adhesive and signaling functions of alpha6beta4 in breast cancer cell survival. The antibodies and data generated herein advance our understanding of alpha6beta4 in regulating tumorigenic processes, and suggest that combination therapies involving alpha6beta4 may be therapeutically effective in breast cancer.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Integrina alfa6beta4/metabolismo , Integrina alfa6beta4/fisiologia , Anticorpos/metabolismo , Apoptose/efeitos dos fármacos , Adesão Celular/fisiologia , Linhagem Celular , Receptores ErbB/metabolismo , Feminino , Humanos , Integrinas/metabolismo , Neoplasias/metabolismo , Transdução de Sinais
17.
Cell Commun Adhes ; 15(4): 317-31, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18979297

RESUMO

Integrin alpha6beta4-mediated adhesion interactions play key roles in keratinocyte and epithelial tumor cell biology. In order to evaluate how alpha6beta4 adhesion interactions contribute to these important cellular processes, the authors generated soluble versions of the integrin by recombinant expression of the subunit ectodomains fused to a human immunoglobulin G (IgG) Fc constant domain. Coexpression of the appropriate subunits enabled dimerization, secretion and purification of stable Fc-containing alpha6beta4 heterodimers. The soluble proteins exhibited the same metal ion and ligand dependency in their binding characteristics as intact alpha6beta4. Using these reagents in combination with anti-beta4 antibodies, the authors identified two distinct functional epitopes on the beta4 subunit. They demonstrated the involvement of one epitope in adhesion interactions and the other in regulating adhesion-independent growth in alpha6beta4-expressing tumor cell lines. The availability of these soluble integrin reagents and the data provided herein help to further delineate the structure-function relationships regulating alpha6beta4 signaling biology.


Assuntos
Integrina alfa6beta4/fisiologia , Integrina beta4/química , Animais , Anticorpos/metabolismo , Células CHO , Adesão Celular , Comunicação Celular , Linhagem Celular Tumoral , Cricetinae , Cricetulus , Dimerização , Humanos , Integrina beta4/imunologia , Integrina beta4/fisiologia , Células K562 , Queratinócitos/citologia , Queratinócitos/metabolismo , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais , Relação Estrutura-Atividade
18.
Structure ; 16(5): 798-808, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18462684

RESUMO

The phosphorylation of IkappaB by the IKK complex targets it for degradation and releases NF-kappaB for translocation into the nucleus to initiate the inflammatory response, cell proliferation, or cell differentiation. The IKK complex is composed of the catalytic IKKalpha/beta kinases and a regulatory protein, NF-kappaB essential modulator (NEMO; IKKgamma). NEMO associates with the unphosphorylated IKK kinase C termini and activates the IKK complex's catalytic activity. However, detailed structural information about the NEMO/IKK interaction is lacking. In this study, we have identified the minimal requirements for NEMO and IKK kinase association using a variety of biophysical techniques and have solved two crystal structures of the minimal NEMO/IKK kinase associating domains. We demonstrate that the NEMO core domain is a dimer that binds two IKK fragments and identify energetic hot spots that can be exploited to inhibit IKK complex formation with a therapeutic agent.


Assuntos
Quinase I-kappa B/química , Sequência de Aminoácidos , Sítios de Ligação , Biofísica/métodos , Dimerização , Escherichia coli/genética , Humanos , Interações Hidrofóbicas e Hidrofílicas , Quinase I-kappa B/isolamento & purificação , Quinase I-kappa B/metabolismo , Corpos de Inclusão/química , Modelos Moleculares , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular , Ligação Proteica , Conformação Proteica , Dobramento de Proteína , Estrutura Terciária de Proteína , Homologia de Sequência de Aminoácidos , Análise Espectral Raman
19.
Eur J Biochem ; 270(17): 3610-8, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12919325

RESUMO

The disulfide structure of the CRIPTO/FRL-1/CRYPTIC (CFC) domain of human Cripto protein was determined by a combination of enzymatic and chemical fragmentation, followed by chromatographic separation of the fragments, and characterization by mass spectrometry and N-terminal sequencing. These studies showed that Cys115 forms a disulfide bond with Cys133, Cys128 with Cys149, and Cys131 with Cys140. Protein database searching and molecular modeling revealed that the pattern of disulfide linkages in the CFC domain of Cripto is the same as that in PARS intercerebralis major Peptide C (PMP-C), a serine protease inhibitor, and that the EGF-CFC domains of Cripto are predicted to be structurally homologous to the EGF-VWFC domains of the C-terminal extracellular portions of Jagged 1 and Jagged 2. Biochemical studies of the interactions of ALK4 with the CFC domain of Cripto by fluorescence-activated cell sorter analysis indicate that the CFC domain binds to ALK4 independent of the EGF domain. A molecular model of the CFC domain of Cripto was constructed based on the nuclear magnetic resonance structure of PMP-C. This model reveals a hydrophobic patch in the domain opposite to the presumed ALK4 binding site. This hydrophobic patch may be functionally important for the formation of intra or intermolecular complexes.


Assuntos
Ciclotídeos , Fator de Crescimento Epidérmico , Proteínas de Membrana , Proteínas de Neoplasias/química , Proteínas de Neoplasias/metabolismo , Proteínas , Receptores de Ativinas Tipo I/metabolismo , Sequência de Aminoácidos , Animais , Células CHO , Proteínas de Transporte/química , Proteínas de Transporte/genética , Cricetinae , Dissulfetos/química , Citometria de Fluxo , Proteínas Ligadas por GPI , Humanos , Proteínas de Insetos/química , Proteínas de Insetos/genética , Peptídeos e Proteínas de Sinalização Intercelular , Proteína Jagged-2 , Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Modelos Moleculares , Dados de Sequência Molecular , Proteínas de Neoplasias/genética , Fragmentos de Peptídeos/análise , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
20.
J Clin Invest ; 112(4): 575-87, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12925698

RESUMO

Cripto, a cell surface-associated protein belonging to the EGF-CFC family of growth factor-like molecules, is overexpressed in many human solid tumors, including 70-80% of breast and colon tumors, yet how it promotes cell transformation is unclear. During embryogenesis, Cripto complexes with Alk4 via its unique cysteine-rich CFC domain to facilitate signaling by the TGF-beta ligand Nodal. We report, for the first time to our knowledge, that Cripto can directly bind to another TGF-beta ligand, Activin B, and that Cripto overexpression blocks Activin B growth inhibition of breast cancer cells. This result suggests a novel mechanism for antagonizing Activin signaling that could promote tumorigenesis by deregulating growth homeostasis. We show that an anti-CFC domain antibody, A8.G3.5, both disrupts Cripto-Nodal signaling and reverses Cripto blockade of Activin B-induced growth suppression by blocking Cripto's association with either Alk4 or Activin B. In two xenograft models, testicular and colon cancer, A8.G3.5 inhibited tumor cell growth by up to 70%. Both Nodal and Activin B expression was found in the xenograft tumor, suggesting that either ligand could be promoting tumorigenesis. These data validate that functional blockade of Cripto inhibits tumor growth and highlight antibodies that block Cripto signaling mediated through its CFC domain as an important class of antibodies for further therapeutic development.


Assuntos
Fator de Crescimento Epidérmico , Glicoproteínas de Membrana , Proteínas de Neoplasias/química , Proteínas de Neoplasias/imunologia , Proteínas , Receptores de Ativinas Tipo I/metabolismo , Ativinas/metabolismo , Animais , Anticorpos Monoclonais/metabolismo , Neoplasias da Mama/patologia , Células CHO , Divisão Celular , Separação Celular , Transformação Celular Neoplásica , Cricetinae , Relação Dose-Resposta a Droga , Epitopos , Citometria de Fluxo , Proteínas Ligadas por GPI , Humanos , Immunoblotting , Imunoglobulina G/metabolismo , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intercelular , Ligantes , Masculino , Camundongos , Camundongos Nus , Transplante de Neoplasias , Proteína Nodal , Plasmídeos/metabolismo , Testes de Precipitina , Ligação Proteica , Estrutura Terciária de Proteína , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Fatores de Tempo , Transfecção , Fator de Crescimento Transformador beta/metabolismo , Células Tumorais Cultivadas
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