RESUMO
The incidences of lung tumors and thymic lymphomas were increased in young adult male RF mice receiving 30 milligrams of methyl meth anesulfonate per kilogram of body weight daily in the drinking water throughout life. Differences in oncogenicity between treatment with methyl methanesulfonate and with dimethylnitrosamine or diethylnitrosamine suggest a qualitative difference between the site (or sites) of alkylation by methyl methanesulfonate and by dimethylnitrosamine or diethylnitrosamine within the nucleic acids.
Assuntos
Carcinógenos , Neoplasias Pulmonares/induzido quimicamente , Linfoma/induzido quimicamente , Neoplasias Experimentais/induzido quimicamente , Nitrosaminas , Ácidos Sulfônicos , Neoplasias do Timo/induzido quimicamente , Alquilação , Animais , Animais Recém-Nascidos , Leucemia Mieloide/induzido quimicamente , Neoplasias Hepáticas/induzido quimicamente , Masculino , Camundongos , Neoplasias Gástricas/induzido quimicamenteRESUMO
Angiogenic sprouting can contribute adaptively, or mal-adaptively, to a myriad of conditions including ischemic heart disease and cancer. While the cellular and molecular systems that regulate tip versus stalk endothelial cell (EC) specification during angiogenesis are known, those systems that regulate their distinct actions remain poorly understood. Pre-clinical and clinical findings support sustained adrenergic signaling in promoting angiogenesis, but links between adrenergic signaling and angiogenesis are lacking; importantly, adrenergic agents alter the activation status of the cAMP signaling system. Here, we show that the cAMP effector, PKA, acts in a cell autonomous fashion to constitutively reduce the in vitro and ex vivo angiogenic sprouting capacity of ECs. At a cellular level, we observed that silencing or inhibiting PKA in human ECs increased their invasive capacity, their generation of podosome rosettes and, consequently, their ability to degrade a collagen matrix. While inhibition of either Src-family kinases or of cdc42 reduced these events in control ECs, only cdc42 inhibition, or silencing, significantly impacted them in PKA(Cα)-silenced ECs. Consistent with these findings, cell-based measurements of cdc42 activity revealed that PKA activation inhibits EC cdc42 activity, at least in part, by promoting its interaction with the inhibitory regulator, guanine nucleotide dissociation inhibitor-α (RhoGDIα).
Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/fisiologia , Células Endoteliais/metabolismo , Neovascularização Patológica , Neovascularização Fisiológica/efeitos dos fármacos , Podossomos , Proteína cdc42 de Ligação ao GTP/fisiologia , Linhagem Celular , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Células Endoteliais/citologia , Células Endoteliais/patologia , Humanos , Neovascularização Fisiológica/fisiologia , Podossomos/efeitos dos fármacos , Proteína cdc42 de Ligação ao GTP/antagonistas & inibidores , Inibidor alfa de Dissociação do Nucleotídeo Guanina rho/farmacologia , Quinases da Família src/antagonistas & inibidores , Quinases da Família src/fisiologiaRESUMO
The ubiquitous Fer protein-tyrosine kinase has been proposed to regulate diverse processes such as cell growth, cell adhesion, and neurite outgrowth. To gain insight into the biological function of Fer, we have targeted the fer locus with a kinase-inactivating missense mutation (fer(D743R)). Mice homozygous for this mutation develop normally, have no overt phenotypic differences from wild-type mice, and are fertile. Since these mice lack both Fer and the testis-specific FerT kinase activities, these proteins are clearly not essential for development and survival. No differences were observed in overall cellularity of bone marrow, spleen, or thymus in the absence of Fer activity. While most platelet-derived growth factor (PDGF)-induced tyrosine phosphorylation was unchanged in fer(D743R) homozygous embryonic fibroblasts, cortactin phosphorylation was reduced. However, Fer kinase activity was not required for PDGF-induced Stat3, p120(ctn), or epidermal growth factor (EGF)-induced beta-catenin phosphorylation. Also, no defects were observed in changes to the actin cytoskeleton, adherens junctions, or focal adhesions in PDGF- or EGF-stimulated fer(D743R) homozygous embryonic fibroblasts. Therefore, Fer likely serves a redundant role in regulating cell growth, cell adhesion, retinal development, and spermatogenesis but is required for efficient phosphorylation of cortactin.
Assuntos
Fertilidade/genética , Deleção de Genes , Proteínas dos Microfilamentos/metabolismo , Proteínas Proto-Oncogênicas/deficiência , Transativadores , Actinas/metabolismo , Alelos , Animais , Cateninas , Moléculas de Adesão Celular/metabolismo , Cortactina , Proteínas do Citoesqueleto/metabolismo , Citoesqueleto/química , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Fator de Crescimento Epidérmico/farmacologia , Fibroblastos , Marcação de Genes , Genótipo , Imuno-Histoquímica , Camundongos , Camundongos Knockout , Fenótipo , Fosfoproteínas/metabolismo , Fosforilação/efeitos dos fármacos , Fator de Crescimento Derivado de Plaquetas/farmacologia , Proteínas Tirosina Quinases , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Taxa de Sobrevida , beta Catenina , delta CateninaRESUMO
The La autoantigen is an RNA-binding protein that is involved in initiation and termination of RNA polymerase III transcription. It also binds several viral RNAs, including those of poliovirus and human immunodeficiency virus (HIV). Binding of the La protein to these RNAs enhances their translation in vitro (K. Meerovitch, Y.V. Svitkin, H.S. Lee, F. Lejbkowicz, D.J. Kenan, E.K.L. Chan, V.L. Agol, J.D. Keene, and N. Sonenberg, J. Virol. 67:3798-3807, 1993, and Y.V. Svitkin, A. Pause, and N. Sonenberg, J. Virol. 68:7001-7007, 1994). Here, a functional domain in the carboxy-terminal half of La that is distinct from the RNA-binding domain is described. Deletion of this domain abrogated the ability of La protein to enhance translation of poliovirus RNA and a hybrid HIV trans-activation-response element-chloramphenicol acetyltransferase mRNA. Far-Western assays indicated that the La protein homodimerized in vitro, and the C-terminal deletions that caused a loss of activity in translation also abrogated the dimerization signal. Gel filtration chromatography of recombinant La protein confirmed that La protein exists as a dimer under native conditions. Addition of the purified dimerization domain resulted in a loss of translation stimulatory activity of La protein in cell-free-translation reactions.
Assuntos
Autoantígenos/química , Autoantígenos/farmacologia , Biossíntese de Proteínas/efeitos dos fármacos , Ribonucleoproteínas/química , Ribonucleoproteínas/farmacologia , Autoantígenos/genética , Autoantígenos/isolamento & purificação , Cloranfenicol O-Acetiltransferase/genética , Dimerização , HIV-1/genética , Humanos , Peso Molecular , Poliovirus/genética , RNA/metabolismo , RNA Mensageiro/metabolismo , RNA Viral/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/isolamento & purificação , Ribonucleoproteínas/genética , Ribonucleoproteínas/isolamento & purificação , Deleção de Sequência , Antígeno SS-BRESUMO
Aberrant epidermal growth factor receptor (EGFR) signaling in non-small cell lung cancer (NSCLC) is linked to tumor progression, metastasis and poor survival rates. Here we report the role of Cdc42-interacting protein 4 (CIP4) in the regulation of NSCLC cell invasiveness and tumor metastasis. CIP4 was highly expressed in a panel of NSCLC cell lines and normal lung epithelial cell lines. Stable knockdown (KD) of CIP4 in lung adenocarcinoma H1299 cells, expressing wild-type EGFR, led to increased EGFR levels on the cell surface and defects in sustained activation of Erk kinase in H1299 cells treated with EGF. CIP4 localized to leading edge projections in NSCLC cells, and CIP4 KD cells displayed defects in EGF-induced cell motility and invasion through extracellular matrix. This correlated with reduced expression and activity of matrix metalloproteinase-2 (MMP-2) in CIP4 KD cells compared with control. In xenograft assays, CIP4 silencing had no effect on tumor growth but resulted in significant defects in spontaneous metastases to the lungs from these subcutaneous tumors. This correlated with reduced expression of the Erk target gene Zeb1 and the Zeb1 target gene MMP-2 in CIP4 KD tumors compared with control. CIP4 also enhanced rates of metastasis to the liver and lungs in an intrasplenic experimental metastasis model. In human NSCLC tumor sections, CIP4 expression was elevated greater than or equal to twofold in 43% of adenocarcinomas and 32% of squamous carcinomas compared with adjacent normal lung tissues. Analysis of microarray data for NSCLC patients also revealed that high CIP4 transcript levels correlated with reduced overall survival. Together, these results identify CIP4 as a positive regulator of NSCLC metastasis and a potential poor prognostic biomarker in lung adenocarcinoma.
Assuntos
Adenocarcinoma/diagnóstico , Adenocarcinoma/patologia , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/patologia , Proteínas Associadas aos Microtúbulos/fisiologia , Adenocarcinoma/genética , Adenocarcinoma/mortalidade , Adenocarcinoma de Pulmão , Idoso , Animais , Biomarcadores Tumorais/fisiologia , Carcinoma Pulmonar de Células não Pequenas/diagnóstico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Células Cultivadas , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidade , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Antígenos de Histocompatibilidade Menor , Metástase Neoplásica , Prognóstico , Análise de SobrevidaRESUMO
BACKGROUND: Proteases play a major role in inflammatory diseases of the gastrointestinal tract. Activatable probes are a major technological advance, enabling sensitive detection of active proteases in tissue samples. Our aim was to synthesize an activatable probe for cathepsin S and validate its use in a mouse model of colitis. METHODS: We designed and synthesized a new fluorescent activatable probe, NB200, for the detection of active cathepsin S. Colitis was induced in C57BL/6 mice by the administration of 3% dextran sulfate sodium (DSS). Homogenized mouse colons, with or without the addition of the specific cathepsin S inhibitor MV026031, were incubated with NB200 in a fluorescent plate reader. KEY RESULTS: NB200 selectively detected purified cathepsin S and not other common inflammatory proteases. Homogenates of colon from mice with DSS colitis induced a significant fluorescent increase when compared to control animals (control vs DSS: p < 0.05 at 200 min and p < 0.01 at 220-240 min), indicating cathepsin S activation. The cathepsin S inhibitor abolished this increase in fluorescence (DSS vs DSS + MV026031: p < 0.05 at 140 min, p < 0.01 at 180 min, p < 0.001 at 200-240 min), which confirms cathepsin S activation. Cathepsin S activity correlated with the disease activity index (Spearman r = 0.77, p = 0.017). CONCLUSIONS & INFERENCES: Our investigation has demonstrated the utility of activatable probes for detecting protease activity in intestinal inflammation. Panels of such probes may allow 'signature' protease profiles to be established for a range of inflammatory diseases and disorders.
Assuntos
Catepsinas/análise , Colite/enzimologia , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/farmacologia , Animais , Colite/induzido quimicamente , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Fps/Fes and Fer proto-oncoproteins are structurally related non-receptor protein-tyrosine kinases implicated in signaling downstream from cytokines, growth factors and immune receptors. We show that Fps/Fes and Fer are expressed in human and mouse platelets, and are activated following stimulation with collagen and collagen-related peptide (CRP), suggesting a role in GPVI receptor signaling. Fer was also activated following stimulation with thrombin and a protease-activated receptor4 (PAR4)-activating peptide, suggesting a role in signaling downstream from the G protein-coupled PAR4. There were no detectable perturbations in CRP-induced activation of Syk, PLCgamma2, cortactin, Erk, Jnk, Akt or p38 in platelets from mice lacking Fps/Fes, Fer, or both kinases. Platelets lacking Fps/Fes, from a targeted fps/fes null strain of mice, showed increased rates and amplitudes of collagen-induced aggregation, relative to wild-type platelets. P-Selectin expression was also elevated on the surface of Fps/Fes-null platelets in response to CRP. Fer-deficient platelets, from mice targeted with a kinase-inactivating mutation, disaggregated more rapidly than wild-type platelets in response to ADP. This report provides the first evidence that Fps/Fes and Fer are expressed in platelets and become activated downstream from the GPVI collagen receptor, and that Fer is activated downstream from a G-protein coupled receptor. Furthermore, using targeted mouse models we show that deficiency in Fps/Fes or Fer resulted in disregulated platelet aggregation and disaggregation, demonstrating a role for these kinases in regulating platelet functions.
Assuntos
Proteínas de Fusão gag-onc/fisiologia , Agregação Plaquetária , Proteínas Tirosina Quinases/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Difosfato de Adenosina/farmacologia , Animais , Plaquetas/enzimologia , Colágeno/farmacologia , Proteínas de Fusão gag-onc/análise , Humanos , Camundongos , Camundongos Transgênicos , Fosforilação/efeitos dos fármacos , Agregação Plaquetária/efeitos dos fármacos , Glicoproteínas da Membrana de Plaquetas , Proteínas Tirosina Quinases/análise , Proteínas Proto-Oncogênicas/análise , Receptores de Superfície Celular , Transdução de SinaisRESUMO
A method is described of measuring the response of human lymphocytes to phytohaemagglutinin stimulation using iododeoxyuridine labelled with the gamma-emitting isotope (125)I. The results indicate useful clinical applications.
Assuntos
Idoxuridina , Linfócitos/imunologia , DNA/biossíntese , Humanos , Técnicas In Vitro , Isótopos de Iodo , Lectinas/farmacologia , Ativação Linfocitária , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Métodos , TrítioRESUMO
The removal of the promutagenic DNA alkylation product O6-methylguanine from different fractions of rat liver DNA has been examined using the technique of DNA-DNA reassociation. Male Wistar rats were given a low non-toxic dose of N,N-dimethylnitrosamine (DMN) (2 mg/kg) and killed 3 or 18 h later (a period corresponding to the removal of 50% of the O6-methylguanine from 'total' liver (DNA). DNA was extracted from liver, denatured in alkali and incubated at 60 degrees C for periods corresponding to the reassociation of highly repetitive (polycopy), middle repetitive and 'unique' sequences i.e. different 'kinetic' classes of DNA. Reassociated and single-stranded DNA were separated by hydroxyapatite chromatography and analyse for O6-methylguanine content. Three hours after administration of DMN the levels of O6-methylguanine in the reassociated and single-stranded DNA were the same after each period of reassociation indicating that O6-methylguanine was randomly distributed among the DNA classes. At 18 h the levels of O6-methylguanine were again the same in the reassociated and single-stranded DNA but approx. 50% lower than in the 3 h DNA samples. The rate of loss of O6-methylguanine from the three DNA classes was thus the same and there was therefore no indication of preferential removal of this base from any one kinetic class of DNA under the conditions used.
Assuntos
Reparo do DNA , Dimetilnitrosamina/farmacologia , Guanina/análogos & derivados , Fígado/metabolismo , Animais , Cromatina/metabolismo , DNA de Cadeia Simples/metabolismo , Guanina/metabolismo , Masculino , Metilação , Desnaturação de Ácido Nucleico , RatosRESUMO
Metastatic breast adenocarcinomas display activation signatures for signaling pathways that trigger cell motility and tissue invasion. Here, we report that the adaptor protein transducer of Cdc42-dependent actin assembly-1 (Toca-1) is expressed in highly invasive breast cancers and regulates their metastatic phenotypes. We show that Toca-1 localizes to the filamentous actin-rich core of invadopodial protrusions actively degrading the extracellular matrix (ECM). Toca-1 colocalizes with Cortactin, and we show that this interaction is mediated by the SH3 domain of Toca-1. Stable knockdown (KD) of Toca-1 expression in MDA-MB-231 cells led to a significant defect in epidermal growth factor (EGF)-induced cell migration and invasion. Toca-1 KD cells also showed significant defects in EGF- and Src-induced ECM digestion and formation of invadopodial membrane protrusions. To test the role of Toca-1 in metastasis, we achieved stable Toca-1 KD in both human and rat metastatic breast adenocarcinoma cell lines. Orthotopic tumor xenografting of control and Toca-1 KD cells in natural-killer /B-/T-cell-deficient mice revealed a significant defect in spontaneous lung metastases with Toca-1 silencing in vivo. In contrast, no defects in primary tumor growth or lung seeding following tail vein injection of Toca-1 KD cells was observed, suggesting that Toca-1 functions at an early step in the dissemination of metastatic breast tumor cells. Taken together, our results identify Toca-1 as a proinvasive protein in breast adenocarcinoma and a potential therapeutic target to limit tumor metastasis.
Assuntos
Adenocarcinoma/patologia , Neoplasias da Mama/patologia , Proteínas de Transporte/metabolismo , Matriz Extracelular/metabolismo , Adenocarcinoma/metabolismo , Animais , Neoplasias da Mama/metabolismo , Proteínas de Transporte/genética , Linhagem Celular Tumoral , Movimento Celular , Extensões da Superfície Celular/metabolismo , Cortactina , Fator de Crescimento Epidérmico/metabolismo , Feminino , Humanos , Camundongos , Invasividade Neoplásica , Metástase Neoplásica , RatosAssuntos
Carcinoma Hepatocelular/induzido quimicamente , Carcinoma de Células Escamosas/induzido quimicamente , Neoplasias Esofágicas/induzido quimicamente , Neoplasias Pulmonares/induzido quimicamente , Nitrosaminas , Neoplasias Gástricas/induzido quimicamente , Adenoma/induzido quimicamente , Adenoma/epidemiologia , Animais , Neoplasias Hepáticas , Masculino , Camundongos , Neoplasias Experimentais/induzido quimicamenteAssuntos
Neoplasias Hepáticas/induzido quimicamente , Neoplasias Pulmonares/induzido quimicamente , Nitrosaminas , Adenoma/induzido quimicamente , Animais , Hemangioendotelioma/induzido quimicamente , Hemangiossarcoma/induzido quimicamente , Masculino , Metilação , Metástase Neoplásica , Ratos , Fatores de TempoRESUMO
BACKGROUND: Imidocarb or a combination of atovaquone and azithromycin (A&A) has been suggested for treatment of cats with cytauxzoonosis, but neither has been prospectively evaluated for efficacy. HYPOTHESIS/OBJECTIVES: That survival to hospital discharge is improved by treatment with A&A as compared with imidocarb. ANIMALS: Eighty acutely ill cats with Cytauxzoon felis infection treated at one of 18 veterinary clinics in 5 states. METHODS: An open-label, randomized prospective study compared survival in cats treated with atovaquone (15 mg/kg p.o. q8h) and azithromycin (10 mg/kg p.o. q24h) or imidocarb (3.5 mg/kg i.m.). All received heparin, fluids, and supportive care. Clinical and clinicopathologic data from initial presentation were collated. Parasitemia was quantified (n = 79) and pathogens genotyped (n = 60). Logistic regression was used to determine the impact of treatment group on the primary endpoint, survival to hospital discharge or death. Covariants were analyzed by rank-sum testing. RESULTS: Of 53 cats treated with A&A, 32 (60%) survived to discharge while only 7 of 27 cats (26%) treated with imidocarb survived (P = .0036; odds ratio 7.2, 95% CI 2.2, 24). Cats with a lower parasitemia were more likely to survive, as were cats with higher white blood cell counts and lower total bilirubin. Unique pathogen genotypes were identified from 15 cats, while genotype isolated from 21 cats had been described previously. There were multiple pathogen genotypes identified in 24 cats. CONCLUSIONS AND CLINICAL IMPORTANCE: Survival to discharge was more likely in cats treated with A&A as compared with imidocarb, although case fatality rate remained high.
Assuntos
Antiprotozoários/uso terapêutico , Atovaquona/uso terapêutico , Azitromicina/uso terapêutico , Doenças do Gato/tratamento farmacológico , Imidocarbo/análogos & derivados , Piroplasmida/isolamento & purificação , Infecções Protozoárias em Animais/tratamento farmacológico , Animais , Doenças do Gato/parasitologia , Gatos , DNA de Protozoário/química , DNA de Protozoário/genética , Quimioterapia Combinada/veterinária , Feminino , Genótipo , Imidocarbo/uso terapêutico , Modelos Logísticos , Masculino , Parasitemia/tratamento farmacológico , Parasitemia/parasitologia , Parasitemia/veterinária , Piroplasmida/genética , Reação em Cadeia da Polimerase/veterinária , Estudos Prospectivos , Infecções Protozoárias em Animais/parasitologia , Análise de SobrevidaAssuntos
DNA/análise , Guanina/análise , Regeneração Hepática , Nitrosaminas/farmacologia , Animais , Animais Recém-Nascidos , Radioisótopos de Carbono , Divisão Celular , Cromatografia por Troca Iônica , DNA/metabolismo , Dimetilaminas , Interações Medicamentosas , Estabilidade de Medicamentos , Feminino , Guanina/metabolismo , Meia-Vida , Hepatectomia , Fígado/metabolismo , Masculino , Ácido Orótico/metabolismo , Ratos , Fatores de Tempo , TrítioAssuntos
Ácidos Sulfônicos/metabolismo , Animais , Bussulfano/metabolismo , Dióxido de Carbono/análise , Isótopos de Carbono , Cromatografia em Papel , Ésteres/metabolismo , Fezes/análise , Fêmur/análise , Glicóis/urina , Haplorrinos , Intestinos/análise , Rim/análise , Fígado/análise , Pulmão/análise , Camundongos , Músculos/análise , Miocárdio/análise , Coelhos , Ratos , Especificidade da Espécie , Baço/análise , Ácidos Sulfônicos/administração & dosagem , Ácidos Sulfônicos/análise , Ácidos Sulfônicos/sangue , Ácidos Sulfônicos/urina , Isótopos de EnxofreAssuntos
Alquilantes , Infertilidade Masculina/induzido quimicamente , Inseticidas , Espermatozoides/efeitos dos fármacos , Ácidos Sulfônicos , Animais , Antracenos , Autorradiografia , Azirinas , Bussulfano/toxicidade , Ésteres , Feminino , Fertilidade/efeitos dos fármacos , Inseticidas/administração & dosagem , Masculino , Camundongos , RatosAssuntos
DNA , Guanina/metabolismo , Fígado/metabolismo , Alquilantes/farmacologia , Animais , Isótopos de Carbono , Cromatografia por Troca Iônica , Estabilidade de Medicamentos , Hidrólise , Cinética , Fígado/efeitos dos fármacos , Masculino , Metilação , RNA Ribossômico/metabolismo , Ratos , Fatores de TempoAssuntos
Leucemia Experimental/induzido quimicamente , Metilcolantreno , Animais , Carcinoma de Células Escamosas/induzido quimicamente , Diagnóstico Diferencial , Leucemia/diagnóstico , Leucemia Linfoide/induzido quimicamente , Leucemia Mieloide/diagnóstico , Contagem de Leucócitos , Linfoma/induzido quimicamente , Camundongos , Transplante de Neoplasias , Sarcoma Experimental , Transplante HomólogoRESUMO
BACKGROUND AND AIMS: Fer kinase is activated by a number of growth factors and cytokines, and phosphorylates cortactin during cell shape change induced cortical actin reorganisation. In addition, Fer participates in cytoskeletal interactions mediated by cadherins, platelet endothelial cell adhesion molecule 1 (PECAM-1), and integrins, and has recently been implicated in limiting the innate immune response. Here we examined the role of Fer in modulating leucocyte recruitment and epithelial barrier function in the gut in response to lipopolysaccharide (LPS). METHODS: Mice targeted with a kinase inactivating mutation (FerDR) or strain matched wild-type (129Sv/J) mice were studied after intraperitoneal injection of LPS. Intravital microscopy was used to examine intestinal leucocyte kinetics, and leucocyte infiltration was assessed by fluorescence activated cell sorting. Systemic inflammation was assessed by measuring lung myeloperoxidase activity. Epithelial barrier function was assessed in vivo using blood to lumen 51Cr-EDTA clearance, with or without antibody based depletion of circulating neutrophils. RESULTS: LPS induced a significant increase in leucocyte adhesion and neutrophil infiltration into the intestinal tissue, and increased blood to lumen 51Cr-EDTA clearance. Pretreatment with neutrophil depleting antibody completely abrogated this response in wild-type mice. In FerDR mice, LPS induced leucocyte adhesion within the intestinal venules was exacerbated and associated with a trend towards increased neutrophil transmigration relative to wild-type mice. Surprisingly, LPS induced epithelial barrier permeability was increased 2.5-fold in FerDR mice relative to wild-type mice, and this barrier defect was only partly attenuated by depleting circulating neutrophils by >93 %. CONCLUSIONS: Fer plays a role in regulating LPS induced epithelial barrier dysfunction in vivo through both neutrophil dependent and neutrophil independent mechanisms.
Assuntos
Células Epiteliais/imunologia , Intestinos/imunologia , Leucócitos/imunologia , Proteínas Proto-Oncogênicas/fisiologia , Animais , Adesão Celular/imunologia , Movimento Celular/imunologia , Imunidade Celular , Intestino Delgado/imunologia , Contagem de Leucócitos/métodos , Lipopolissacarídeos/imunologia , Camundongos , Neutrófilos/imunologia , Permeabilidade , Proteínas Tirosina Quinases/imunologia , Proteínas Proto-Oncogênicas/imunologiaRESUMO
Dibutylnitrosamine has been administered continuously in the drinking water to two groups of C57BL/6 mice. The first group (50 males, 50 females) received 30 mg./kg./day and the second (50 males, 50 females) 7.6 mg./kg./day. Of mice reaching autopsy squamous cell carcinoma of the bladder was found in 44/90 at the high dose and 19/89 at the low dose. Bladder tumours were found predominantly in males, the ratio of tumours in males and females being 4.4: 1 and 8.5: 1 at the high and low dose levels, respectively. Carcinomas and papillomas of the oesophagus were found in all but 2 of the females and all but 6 of the males. In addition 5 carcinomas of the fore-stomach in the low dose group and a total in both groups of 13 tumours of the soft palate and tongue were found. The mean cumulative doses and respective induction times for the high and low dose groups were 7.4 and 2.0 g./kg., and 240 and 260 days.