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1.
Int J Tuberc Lung Dis ; 16(7): 886-90, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22583556

RESUMO

OBJECTIVE: To identify for the first time in Scotland the epidemiological characteristics of tuberculosis (TB) patients who misuse alcohol. DESIGN: A retrospective cohort study using Enhanced Surveillance of Mycobacterial Infections (ESMI) scheme data for adult (aged ≥ 18 years) TB cases notified in Scotland, 2001-2007. Characteristics and treatment outcomes of TB cases with and without recorded alcohol misuse were compared. RESULTS: Of 2419 adult TB cases, alcohol misuse was recorded in 426 (18%). Alcohol misuse was associated with male sex, White ethnicity, birth in the United Kingdom, unemployment, urban residence and socio-economic deprivation. Alcohol misusers were more likely than other TB cases to have pulmonary TB (92% vs. 61%, P < 0.001), be sputum smear-positive (74% vs. 58%, P < 0.001) and be enrolled on directly observed treatment (30% vs. 3%, P < 0.001). Treatment completion rates were respectively 77% and 79% (P = 0.34) in alcohol misusers and other TB cases. CONCLUSION: We have identified epidemiological characteristics associated with alcohol misuse among TB patients in Scotland, notably socio-economic deprivation. We suggest improvements in data collection to allow more robust findings to inform policy decisions to assist the prevention and management of alcohol misuse and reduce the TB incidence in Scotland.


Assuntos
Alcoolismo/epidemiologia , Tuberculose Pulmonar/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alcoolismo/complicações , Alcoolismo/etnologia , Estudos de Coortes , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Vigilância da População , Estudos Retrospectivos , Escócia/epidemiologia , Distribuição por Sexo , Fatores Socioeconômicos , Resultado do Tratamento , Tuberculose Pulmonar/complicações , Reino Unido/epidemiologia , Adulto Jovem
2.
J Urban Health ; 87(4): 576-85, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20535641

RESUMO

In January 2005, passage of California Senate Bill 1159 enabled California's county or city governments to establish disease prevention demonstration projects (DPDPs) through which pharmacies could subsequently register to legally sell up to 10 syringes to adults without a prescription. California's 61 local health jurisdictions (LHJs) were surveyed annually in 2005-2007 to monitor the progress of DPDP implementation and assess program coverage, facilitators, and barriers. Completed surveys were returned by mail, fax, e-mail, phone, or internet. We analyzed 2007 survey data to describe current DPDP status; data from all years were analyzed for trends in approval and implementation status. By 2007, 17 (27.9%) LHJs approved DPDPs, of which 14 (82.4%) had registered 532 (17.8%) of the 2,987 pharmacies in these 14 LHJs. Although only three LHJs added DPDPs since 2006, the number of registered pharmacies increased 102% from 263 previously reported. Among the LHJs without approved DPDPs in 2007, one (2.3%) was in the approval process, seven (16.3%) planned to seek approval, and 35 (81.4%) reported no plans to seek approval. Of 35 LHJs not planning to seek approval, the top four reasons were: limited health department time (40%) or interest (34%), pharmacy disinterest (31%), and law enforcement opposition (26%). Among eight LHJs pursuing approval, the main barriers were "time management" (13%), educating stakeholders (13%), and enlisting pharmacy participation (13%). The17 LHJs with DPDP represent 52% of California's residents; they included 62% of persons living with HIV and 59% of IDU-related HIV cases, suggesting that many LHJs with significant numbers of HIV cases have approved DPDPs. Outcome studies are needed to determine whether SB 1159 had the desired impact on increasing syringe access and reducing blood-borne viral infection risk among California IDUs.


Assuntos
Serviços Comunitários de Farmácia/legislação & jurisprudência , Serviços Comunitários de Farmácia/estatística & dados numéricos , Programas de Troca de Agulhas/legislação & jurisprudência , Programas de Troca de Agulhas/estatística & dados numéricos , Abuso de Substâncias por Via Intravenosa , California , Infecções por HIV/prevenção & controle , Hepatite C/prevenção & controle , Humanos
3.
Crit Rev Oncol Hematol ; 49(3): 245-58, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15036264

RESUMO

Thrombospondins belong to a family of extracellular matrix (ECM) proteins widely found from embryonic to adult tissues. The modular structure of thrombospondins contains a series of peptide sequences implicated in a multiplicity of biological functions. Extracellular matrix undergoes important alterations under proteolysis that occurs in pathological processes like tumorigenesis. An elevated secretion of thrombospondin 1 (TSP1) is often observed in tumors and is sometimes considered as a predictive factor. However, the role of TSP1 in cancer progression remains controversial and must be carefully apprehended. The regulation of cell adhesion, proliferation, apoptosis by TSP1 is examined in the present review and it is clear from the literature and from our investigations that TSP1 presents both stimulatory and inhibitory effects. The exposition of cryptic sites upon conformational changes can partially explain this contradiction. More interestingly, the analysis of TSP1-directed intracellular signaling pathways activated through specific receptors or supramolecular receptors docking systems may be useful to discriminate the precise function of TSP1 in tumor progression. The central role played by TSP1 in the control of matrix-degrading enzyme activation and catabolism reveals attractive tracks of research and highlights the involvement of the lipoprotein receptor-related protein (LRP) receptor in these events. Therefore, TSP1-derived peptides constitute a source of potentially active matrikins which could provide essential tools in cancer therapy.


Assuntos
Invasividade Neoplásica/patologia , Trombospondina 1/fisiologia , Apoptose/fisiologia , Antígenos CD36/metabolismo , Adesão Celular/fisiologia , Divisão Celular/fisiologia , Progressão da Doença , Endocitose/fisiologia , Ativação Enzimática/fisiologia , Matriz Extracelular/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Trombospondina 1/química
4.
FEBS Lett ; 546(2-3): 195-202, 2003 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-12832039

RESUMO

Annexins are widely distributed and have been described in lung as well as in other cells and tissues. Annexin I (ANX AI) is a member of the calcium-dependent phospholipid binding protein family. Besides its anti-inflammatory function, ANX AI has been involved in several mechanisms such as the Erk repression pathway or apoptosis. To investigate the role of ANX AI on apoptosis in broncho-alveolar cells, we have constructed a plasmid containing the ANX AI full length cDNA. Transfected BZR cells displayed a higher level of both forms of ANX AI (37 and 33 kDa) as well as a decrease in cell viability (two-fold versus cells transfected with an empty vector). In order to analyse the endogenous ANX AI processing during stimulus-induced apoptosis, BZR cells were treated with a commonly used inducer, i.e. C2 ceramides. In these conditions, microscopic analysis revealed chromatin condensation in dying cells and the Bcl-2, Bcl-x(L)/Bax mRNA balance was altered. Caspase-3 is one of the key executioners of apoptosis, being responsible for the cleavage of many proteins such as the nuclear enzyme poly(ADP-ribose) polymerase (PARP). We demonstrate that caspase-3 was activated after 4 h treatment in the presence of ceramide leading to the cleavage of PARP. Dose-response experiments revealed that cell morphology and viability modifications following ceramide treatment were accompanied by an increase in endogenous ANX AI processing. Interestingly, in both ceramide and transfection experiments, the ANX AI cleaved form was enhanced whereas pre-treatment with the caspase inhibitor Z-VAD-fmk abolished ANX AI cleavage. In conclusion, this study demonstrates a complex regulatory role of caspase-dependent apoptosis where ANX AI is processed at the N-terminal region which could give susceptibility to apoptosis upon ceramide treatment.


Assuntos
Anexina A1/metabolismo , Apoptose , Processamento de Proteína Pós-Traducional , Sequência de Bases , Western Blotting , Caspases/metabolismo , Linhagem Celular , Primers do DNA , Ativação Enzimática , Poli(ADP-Ribose) Polimerases/metabolismo
5.
J Endocrinol ; 173(2): 345-55, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12010642

RESUMO

Thyrotropin (TSH) and transforming growth factor beta 1 (TGFbeta1) have major roles in the regulation of folliculogenesis and differentiation in thyroid cells. Isolated porcine thyroid cells cultured in the presence of TSH on a plastic surface recover a follicular architecture and exhibit normal functional properties. The addition of TGFbeta1 to the culture medium induces important morphological changes and extracellular matrix remodelling. Similarly, thyroid cells lose their ability to organify iodine and their responsiveness to adenylate cyclase. The aim of this study was to analyse the influence of TGFbeta1 on the functional activity of thyrocytes in suspension culture, independent of follicle disruption. In this system, we demonstrate that TGFbeta1 inhibits expression of thyroperoxidase, NADPH oxidase activity, iodine uptake and, consequently, iodine organification. Moreover, TGFbeta1 decreases basal and TSH-stimulated cAMP production and TSH receptor expression. Taken together, these data converge to demonstrate an essential role of TGFbeta1 in the regulation of the thyroid cell function.


Assuntos
Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Animais , Western Blotting , Células Cultivadas , AMP Cíclico/biossíntese , Eletroforese em Gel de Poliacrilamida , Iodeto Peroxidase/metabolismo , Radioisótopos do Iodo/metabolismo , Microscopia Eletrônica , NADPH Oxidases/metabolismo , Receptores da Tireotropina/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Suínos , Trombospondina 1/metabolismo , Glândula Tireoide/ultraestrutura , Tireotropina/farmacologia , Fator de Crescimento Transformador beta1
6.
J Soc Biol ; 195(2): 165-72, 2001.
Artigo em Francês | MEDLINE | ID: mdl-11723829

RESUMO

Soluble elastin-derived peptides from alkaline or elastase hydrolysis of insoluble elastin, as well as tropoelastin, increase matrix metalloproteinase-2 (MMP-2) production by human skin fibroblasts in culture as determined by gelatin zymography and ELISA. Such an effect is time and concentration dependent; it can be reproduced by synthetic elastin: VGVAPG, PGAIPG, and laminin: LGTIPG, hexapeptides and inhibited by lactose and is therefore elastin receptor-mediated. The steady state levels of MMP-2 mRNAs are invariant following elastin-fibroblasts interaction. Inhibition of phospholipase C (D-609), ADP-ribosylation factor (brefeldin), protein kinase C (RO-318220) and phospholipase D (1-propanol) totally abolished the elastin-mediated increase of MMP-2 production. It suggested that the post-transcriptional mechanism controlling the elastin-mediated overproduction of MMP-2 involved a cascade leading to phospholipase D activation.


Assuntos
Elastina/farmacologia , Fibroblastos/efeitos dos fármacos , Metaloproteinase 2 da Matriz/biossíntese , Fragmentos de Peptídeos/farmacologia , Fatores de Ribosilação do ADP/antagonistas & inibidores , Animais , Brefeldina A/farmacologia , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Bovinos , Dactinomicina/farmacologia , Elastina/química , Eletroforese em Gel de Poliacrilamida , Ativação Enzimática/efeitos dos fármacos , Indução Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Ensaio de Imunoadsorção Enzimática , Fibroblastos/enzimologia , Humanos , Indóis/farmacologia , Lactose/farmacologia , Laminina/farmacologia , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 3 da Matriz/biossíntese , Metaloproteinase 3 da Matriz/genética , Norbornanos , Inibidores da Síntese de Ácido Nucleico/farmacologia , Fragmentos de Peptídeos/síntese química , Fosfatidilinositol Diacilglicerol-Liase , Fosfolipase D/metabolismo , Proteína Quinase C/antagonistas & inibidores , Processamento de Proteína Pós-Traducional/efeitos dos fármacos , Transdução de Sinais , Pele/citologia , Tiocarbamatos , Tionas/farmacologia , Tropoelastina/química , Tropoelastina/farmacologia , Fosfolipases Tipo C/antagonistas & inibidores
7.
Biomaterials ; 22(22): 2993-8, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11575473

RESUMO

Controlling cell shape induced by cell-substrata interaction appears of prime importance to influence subsequent biological processes such as cell migration, proliferation, differentiation or apoptosis. Studies on Swiss 3T3 fibroblasts have recently provided evidence that cell spreading is mediated by integrins and RhoA. Our previous studies showed that on Cuprophan, a cellulose membrane (CU) to which vitronectin adhesive protein is poorly adsorbed, Swiss 3T3 cells are rounded and undergo cAMP-dependent aggregation. In contrast, on a polyacrylonitrile membrane (AN69) that favours the adsorption of vitronectin and fibronectin, cells spread out and contain low concentrations of cAM P. We have now examined the parts played by the three components in the cAMP pathway (receptors, G-proteins and adenylyl cyclase itself) in cAM P-dependent cell aggregation on CU. Experiments with intact cells showed no interaction between the CU and receptors, or between the CU and G-proteins. Assays on membrane preparations plus the Mn-ATP substrate, which uncouples G-proteins and adenylyl cyclase, demonstrated that activation of the cAMP pathway by CU depends primarily on the catalytic activity of the adenylyl cyclase. These investigations provide essential data for the development of biomaterials that favour cell functionality.


Assuntos
Acrilonitrila/análogos & derivados , Adenilil Ciclases/metabolismo , Materiais Biocompatíveis , Tamanho Celular/fisiologia , Celulose/análogos & derivados , AMP Cíclico/metabolismo , Células 3T3 , Resinas Acrílicas , Animais , Adesão Celular , Membrana Celular/metabolismo , Proteínas de Ligação ao GTP/metabolismo , Ligantes , Teste de Materiais , Membranas Artificiais , Camundongos , Receptores de Superfície Celular/metabolismo , Transdução de Sinais
8.
J Endocrinol ; 169(3): 603-11, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11375131

RESUMO

TSH-treated pig thyroid cells reorganize into follicle-like structures and exhibit differentiated functions. TSH also induces a phosphotyrosine phosphatase (PTPase) activity evaluated by phosphorylated substrate hydrolysis. Incubation of thyrocytes with various concentrations of 8-bromo-cyclic AMP or forskolin induces an increase of PTPase activity in a dose-dependent manner. During the culture period, adenylyl cyclase sensitivity, protein binding iodine and PTPase activity progressively increase from the first to the fourth day of the culture. Chronic treatment with phorbol 12-myristate 13-acetate (PMA) significantly inhibits PTPase activity during the first 24 h following PMA addition. GF 109203X, a specific inhibitor of protein kinase C, abolishes the inhibitory effect of PMA. Electrophoresis of membrane extracts allowed us to demonstrate a phosphatase activity at 111 kDa (p111). Vanadate inhibits this activity, indicating that p111 is a PTPase. This p111 is significantly reduced in PMA-treated cells. These data suggest that PTPase activity evidenced at 111 kDa is correlated with a differentiated state of primary cultured pig thyroid cells induced by TSH.


Assuntos
Proteínas Tirosina Fosfatases/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Glândula Tireoide/enzimologia , Tireotropina/farmacologia , Adenilil Ciclases/metabolismo , Animais , Técnicas de Cultura de Células , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , AMP Cíclico/fisiologia , Inibidores Enzimáticos/farmacologia , Indóis/farmacologia , Iodo/metabolismo , Maleimidas/farmacologia , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/fisiologia , Proteínas Tirosina Fosfatases/efeitos dos fármacos , Suínos , Glândula Tireoide/citologia , Glândula Tireoide/efeitos dos fármacos
9.
Cytokine ; 13(3): 174-8, 2001 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-11161461

RESUMO

Interleukin 1 beta (IL-1beta) is often associated with thyroidal autoimmune diseases. This cytokine has been largely described to trigger an important biological signalling pathway: the sphingomyelin/ceramide pathway. In this report we show that IL-1beta induces ceramide formation and sphingomyelin degradation in porcine thyroid cells via the activation of a neutral sphingomyelinase. Among the potential targets of IL-1beta and ceramides action, we have investigated the role of an atypical protein kinase C (PKC), the PKC zeta. We show that both IL-1beta and ceramides lead to an increase of PKCzeta activity. All these results suggest an important role for ceramides and IL-1beta in regulation of thyroid function, leading to cell survival or to apoptosis.


Assuntos
Ceramidas/fisiologia , Interleucina-1/fisiologia , Transdução de Sinais/imunologia , Glândula Tireoide/imunologia , Animais , Células Cultivadas , Isoenzimas/fisiologia , Proteína Quinase C/fisiologia , Esfingomielinas/fisiologia , Suínos , Glândula Tireoide/citologia , Glândula Tireoide/enzimologia
10.
J Biol Chem ; 276(7): 5222-7, 2001 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-11084020

RESUMO

We have established that treatment of cultured human skin fibroblasts with tropoelastin or with heterogenic peptides, obtained after organo-alkaline or leukocyte elastase hydrolysis of insoluble elastin, induces a high expression of pro-collagenase-1 (pro-matrix metalloproteinase-1 (pro-MMP-1)). The identical effect was achieved after stimulation with a VGVAPG synthetic peptide, reflecting the elastin-derived domain known to bind to the 67-kDa elastin-binding protein. This clearly indicated involvement of this receptor in the described phenomenon. This notion was further reinforced by the fact that elastin peptides-dependent MMP-1 up-regulation has not been demonstrated in cultures preincubated with 1 mm lactose, which causes shedding of the elastin-binding protein and with pertussis toxin, which blocks the elastin-binding protein-dependent signaling pathway involving G protein, phospholipase C, and protein kinase C. Moreover, we demonstrated that diverse peptides maintaining GXXPG sequences can also induce similar cellular effects as a "principal" VGVAPG ligand of the elastin receptor. Results of our biophysical studies suggest that this peculiar consensus sequence stabilizes a type VIII beta-turn in several similar, but not identical, peptides that maintain a sufficient conformation to be recognized by the elastin receptor. We have also established that GXXPG elastin-derived peptides, in addition to pro-MMP-1, cause up-regulation of pro-matrix metalloproteinase-3 (pro-stromelysin 1). Furthermore, we found that the presence of plasmin in the culture medium activated these MMP proenzymes, leading to a consequent degradation of collagen substrate. Our results may be, therefore, relevant to pathobiology of inflammation, in which elastin-derived peptides bearing the GXXPG conformation (created after leukocyte-dependent proteolysis) bind to the elastin receptor of local fibroblasts and trigger signals leading to expression and activation of MMP-1 and MMP-3, which in turn exacerbate local connective tissue damage.


Assuntos
Colagenases/genética , Elastina/química , Elastina/farmacologia , Precursores Enzimáticos/genética , Fibroblastos/metabolismo , Regulação para Cima , Células Cultivadas , Dicroísmo Circular , Colágeno/metabolismo , Colagenases/biossíntese , Colagenases/metabolismo , Sequência Consenso , Precursores Enzimáticos/biossíntese , Precursores Enzimáticos/metabolismo , Humanos , Metaloproteinase 1 da Matriz , Metaloendopeptidases/biossíntese , Metaloendopeptidases/genética , Metaloendopeptidases/metabolismo , Peptídeos/química , Peptídeos/farmacologia , Conformação Proteica , RNA Mensageiro/biossíntese , Receptores de Superfície Celular/fisiologia
11.
Lipids ; 35(11): 1259-68, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11132185

RESUMO

Neutral sphingomyelinase (Smase) is a cell membrane-associated phospholipase that hydrolyzes sphingomyelin to phosphocholine and ceramide, a lipid second messenger involved in cell differentiation and/or apoptosis. We first evidenced that porcine cultured thyroid cells could express neutral Smase activity even if thyrotropin (TStH), an essential hormone in thyroid cell differentiation, was found to induce a 1.7-fold decrease in Smase activity. Triggering the ceramide pathway by exogenous addition of neutral bacterial Smase (0.1 U/mL for 48 h), which transiently increased ceramide level by fourfold, drastically modified thyroid cell morphology. The follicle-like structures generated by TSH were disrupted, and the Smase-induced cell spreading was accompanied by a parallel loss of cell ability to iodinate proteins as well as a decrease of the adenylate cyclase system response. These inhibitory effects have been reproduced using short-chain exogenous ceramide analogs (C2-ceramides). Overall these data showed that ceramides emerged as potential mediators of dedifferentiation in thyroid cells.


Assuntos
Diferenciação Celular , Ceramidas/metabolismo , Transdução de Sinais , Glândula Tireoide/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Esfingomielina Fosfodiesterase/metabolismo , Esfingomielina Fosfodiesterase/farmacologia , Suínos , Glândula Tireoide/citologia , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/enzimologia , Tireotropina/farmacologia
12.
Cell Growth Differ ; 11(11): 573-80, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11095246

RESUMO

In the present study, we demonstrate that erythropoietin (Epo) induces the expression and the release of tissue inhibitors of metalloproteinase-1 (TIMP-1) in a time- and dose-dependent manner in Epo-dependent cell line UT-7 cells and in normal human erythroid progenitor cells from cord blood (CD36+) and required de novo protein synthesis. TIMP-1 was not expressed in the absence of Epo. Inhibition of the mitogen-activated protein kinase pathway by the specific inhibitors PD98059 and U0126 and of phosphatidylinositol 3-kinase by LY294002, strongly inhibited Epo-induced TIMP-1 expression and secretion. In the absence of Epo, both latent and active forms of matrix metalloproteinase-9 (MMP-9) were secreted into media. Upon Epo stimulation, MMP-9 and pro-MMP-9 secretion was inhibited in a dose-dependent manner parallel to TIMP-1 induction. The addition of PD98059, U0126, and LY294002 in the presence of Epo restored MMP-9 production in UT-7 and CD36+ cells. Our findings strongly suggest an inversely coordinated regulation of the TIMP-1 gene and MMP-9 production by Epo via mitogen-activated protein kinase and phosphatidylinositol 3-kinase pathways.


Assuntos
Eritropoetina/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Butadienos/farmacologia , Antígenos CD36/metabolismo , Cromonas/farmacologia , Cicloeximida/farmacologia , Relação Dose-Resposta a Droga , Células Precursoras Eritroides/efeitos dos fármacos , Células Precursoras Eritroides/metabolismo , Eritropoetina/antagonistas & inibidores , Flavonoides/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , MAP Quinase Quinase 1 , Metaloproteinase 9 da Matriz/biossíntese , Metaloproteinase 9 da Matriz/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Morfolinas/farmacologia , Nitrilas/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase , Fosforilação/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Inibidor Tecidual de Metaloproteinase-1/genética , Células Tumorais Cultivadas
13.
FEBS Lett ; 485(2-3): 117-21, 2000 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-11094152

RESUMO

We examined the role of the mitogen-activated protein (MAP) kinase pathway in tissue inhibitor of metalloproteinases-1 (TIMP-1)-mediated cellular effects in a human erythroleukemic cell line UT-7. We show that TIMP-1 induced both UT-7 cell erythroid differentiation and proliferation and tyrosine phosphorylation of many intracellular proteins. Using a panel of phosphospecific antibodies, we also demonstrate that phosphorylation of the p38 and c-Jun N-terminal kinases is increased by TIMP-1 whereas phosphorylation of extracellular signal-regulated kinase 1/2 is not induced. Moreover, inhibition of the p38 activity by SB203580 significantly reduces erythroid differentiation induced by TIMP-1, suggesting that the p38 MAP kinase pathway is involved in TIMP-1-induced erythroid differentiation.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Eritrócitos/citologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Inibidor Tecidual de Metaloproteinase-1/farmacologia , Divisão Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Humanos , Imidazóis/farmacologia , Leucemia Eritroblástica Aguda , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Fosforilação , Fosfotirosina/metabolismo , Piridinas/farmacologia , Células Tumorais Cultivadas , Proteínas Quinases p38 Ativadas por Mitógeno
14.
FEMS Microbiol Lett ; 186(1): 67-71, 2000 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-10779714

RESUMO

An alpha-amylase encoding gene from the extremely thermophilic Archaea Thermococcus hydrothermalis was cloned and expressed in Escherichia coli. The encoded alpha-amylase possesses molecular characteristics specific to the Archaea, especially from Pyrococcus species, with biochemical characteristics of the alpha-amylases from Thermococcus. The gene is 1374 bp long and encodes a protein of 457 amino acids composed of a 22 amino acid putative signal peptide and a 435 amino acid mature protein (calculated molecular mass 49236 Da). The T. hydrothermalis recombinant alpha-amylase is optimally active at 75-85 degrees C and at pH 5.0-5.5.


Assuntos
Proteínas Recombinantes/metabolismo , Thermococcus/enzimologia , Thermococcus/genética , alfa-Amilases/genética , alfa-Amilases/metabolismo , Sequência de Aminoácidos , Clonagem Molecular , Escherichia coli/enzimologia , Escherichia coli/genética , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Análise de Sequência de DNA , Temperatura , alfa-Amilases/química , alfa-Amilases/isolamento & purificação
15.
Biomaterials ; 21(10): 1031-8, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10768755

RESUMO

Our previous studies have shown that cells adhering to biomaterials in serum-free conditions increase their content of cyclic AMP (cAMP) and become aggregated. In cells on an acrylonitrile membrane (AN69), these biochemical and morphological changes are prevented by adding 10% foetal calf serum (FCS) to the medium; cells on the cellulose membrane Cuprophan (CU) remain unaffected. The present study examines the roles of vitronectin (VN)- and/or fibronectin (FN)-integrin binding in this inhibition. Competitively blocking VN- and FN-receptors with echistatin increased intracellular cAMP significantly and caused cells on AN69 to aggregate, but did not modify cAMP-dependent cell aggregation on CU. VN or FN adsorbed onto CU also inhibited cAMP production by attached cells and prevented their aggregation, whereas adsorbed BSA had no effect. Therefore, the binding of VN or FN to cell-surface integrins seems to limit the activation of the cAMP pathway initiated by the substratum itself.


Assuntos
Materiais Biocompatíveis , Adesão Celular/fisiologia , AMP Cíclico/fisiologia , Fibronectinas/fisiologia , Integrinas/fisiologia , Vitronectina/fisiologia , 1-Metil-3-Isobutilxantina/farmacologia , Células 3T3 , Adsorção , Animais , Proteínas Sanguíneas/fisiologia , Celulose/análogos & derivados , Meios de Cultura Livres de Soro , Camundongos , Microscopia Eletrônica de Varredura
16.
Biochem Biophys Res Commun ; 266(1): 15-8, 1999 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-10581157

RESUMO

The protein expression and the enzyme activity of the catalytic subunit (C) of the cAMP-dependent protein kinases were studied in porcine thyroid cell primary cultures stimulated with two doses of TSH (0.1 mU/ml and 1 mU/ml) for 1 to 3 days. In TSH-stimulated cells the desensitization of the catalytic subunit activity was accompanied by a simultaneous and parallel decrease of its immunoreactivity. The loss of catalytic subunit was rapid and reached its maximum after 1 day of culture. It is similar in the two subcellular compartments: cytosol and particulate extracts. Contrary to the observed loss of the C subunit protein molecules in TSH-stimulated cells, the expression of the Cbeta subunit mRNA in these cells was increased fivefold compared to controls, while no significant change was observed on the Calpha subunit mRNA. These results suggest that TSH controls the Cbeta subunits of PKA at two levels: at the transcriptional level it increases Cbeta mRNA expression, and at the translational or posttranslational level TSH decreases the amount and the activity of the Cbeta protein molecules.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Glândula Tireoide/enzimologia , Tireotropina/farmacologia , Animais , Western Blotting , Domínio Catalítico/imunologia , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/genética , Proteínas Quinases Dependentes de AMP Cíclico/imunologia , Citosol/efeitos dos fármacos , Citosol/enzimologia , Relação Dose-Resposta a Droga , Isoenzimas/genética , Isoenzimas/imunologia , Isoenzimas/metabolismo , Cinética , Biossíntese de Proteínas/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Suínos , Glândula Tireoide/citologia , Glândula Tireoide/efeitos dos fármacos
17.
J Biol Chem ; 274(48): 33966-72, 1999 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-10567359

RESUMO

We showed that erythropoietin induced rapid glycosylphosphatidylinositol (GPI) hydrolysis and tyrosine phosphorylation of phospholipase C (PLC)-gamma(2) in FDC-P1 cells transfected with the wild-type erythropoietin-receptor. Erythropoietin-induced tyrosine phosphorylation of PLC-gamma(2) was time- and dose-dependent. By using FDC-P1 cells transfected with an erythropoietin receptor devoid of tyrosine residues, we showed that both effects required the tyrosine residues of intracellular domain on the erythropoietin receptor. Erythropoietin-activated PLC-gamma(2) hydrolyzed purified [(3)H]GPI indicating that GPI hydrolysis and PLC-gamma(2) activation under erythropoietin stimulation were correlated. Results obtained on FDC-P1 cells transfected with erythropoietin receptor mutated on tyrosine residues suggest that tyrosines 343, 401, 464, and/or 479 are involved in erythropoietin-induced GPI hydrolysis and tyrosine phosphorylation of PLC-gamma(2), whereas tyrosines 429 and/or 431 seem to be involved in an inhibition of both effects. Thus, our results suggest that erythropoietin regulates GPI hydrolysis via tyrosine phosphorylation of its receptor and PLC-gamma(2) activation.


Assuntos
Eritropoetina/farmacologia , Glicosilfosfatidilinositóis/metabolismo , Animais , Linhagem Celular , Hidrólise/efeitos dos fármacos , Isoenzimas/metabolismo , Mutação , Fosfolipase C gama , Fosforilação/efeitos dos fármacos , Receptores da Eritropoetina/química , Receptores da Eritropoetina/genética , Receptores da Eritropoetina/metabolismo , Transfecção , Fosfolipases Tipo C/metabolismo , Tirosina/metabolismo
18.
Biomed Chromatogr ; 13(7): 465-71, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10534758

RESUMO

Metabolic labelling of inositolphosphate glycan with radioactive precursors is not sufficient to characterize and assess the involvement of the glycosyl phosphatidylinositol/inositolphosphate glycan (GPI/IPG) system in porcine thyroid cell signal transduction machinery. A protocol is described for the isolation and purification of free GPI using differential polarity of lipids and sequential thin layer chromatography. The purification until homogeneity of GPI constitutes a required step for gas chromatographic analysis. Next, successive chemical treatments allowed us to remove the neutral glycan moiety of thyroidal GPI, and its composition was obtained by gas chromatography. The proposed structure is consistent with data available for GPI anchor, but differs from compositional analysis data reported for insulin-sensitive GPI. Our results support the existence in porcine thyroid cells of the GPI/IPG system, which can take part in TSH-dependent signal transduction processes.


Assuntos
Cromatografia Gasosa/métodos , Cromatografia em Camada Fina/métodos , Glicosilfosfatidilinositóis/química , Polissacarídeos/isolamento & purificação , Glândula Tireoide/química , Animais , Células Cultivadas , Traçadores Radioativos , Suínos , Glândula Tireoide/citologia
19.
Biochem Biophys Res Commun ; 260(3): 634-40, 1999 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-10403818

RESUMO

Triggering the ceramide pathway by exogenous treatment with neutral sphingomyelinase (Smase) inhibited human keratinocyte growth rate, while having no influence on cell apoptosis. Increasing the ceramide content of keratinocytes with Smase (100 U/ml) or C6-ceramide (1 microM) enhanced matrix metalloproteinase (MMP)-9 production. On the contrary, levels of MMP-2 secretion were unchanged. The inhibition of keratinocyte growth rate induced by ceramide could be annihilated by a peptide hydroxamate MMP inhibitor or an MMP-9 blocking antibody. In addition, inhibiting MMP-9 activity in control keratinocyte culture was found to stimulate keratinocyte proliferation. These data suggest a pivotal function of MMP-9 in the control of keratinocyte growth.


Assuntos
Divisão Celular/efeitos dos fármacos , Ceramidas/farmacologia , Colagenases/metabolismo , Queratinócitos/citologia , Anticorpos/imunologia , Anticorpos/farmacologia , Apoptose/efeitos dos fármacos , Células Cultivadas , Ceramidas/metabolismo , Colagenases/biossíntese , Colagenases/imunologia , Relação Dose-Resposta a Droga , Fator de Crescimento Epidérmico/farmacologia , Gelatinases/antagonistas & inibidores , Gelatinases/metabolismo , Células HL-60 , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/enzimologia , Queratinócitos/metabolismo , Metaloproteinase 2 da Matriz , Metaloproteinase 9 da Matriz , Inibidores de Metaloproteinases de Matriz , Metaloendopeptidases/antagonistas & inibidores , Metaloendopeptidases/metabolismo , Fenilalanina/análogos & derivados , Fenilalanina/farmacologia , Esfingomielina Fosfodiesterase/metabolismo , Esfingosina/análogos & derivados , Esfingosina/farmacologia , Tiofenos/farmacologia , Fatores de Tempo
20.
J Cell Sci ; 112 ( Pt 9): 1405-16, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10194419

RESUMO

Transforming growth factor beta1 (TGF-beta1) is a secreted polypeptide that is thought to play a major role in the regulation of folliculogenesis and differentiation of thyroid cells. On porcine thyroid follicular cells cultured on plastic substratum, TGF-beta1, in a concentration-dependent way, promoted the disruption of follicles, cell spreading, migration and confluency by a mechanism that did not involve cell proliferation. TGF-beta1 strongly activated the production of thrombospondin-1 and (alpha)vbeta3 integrin in a concentration-dependent manner whereas the expression of thyroglobulin was unaffected. Anisomycin, an inhibitor of protein synthesis, inhibited the effect of TGF-beta1 on cell organization. Thrombospondin-1 reproduced the effect of TGF-beta1. In the presence of thrombospondin-1 cells did not organize in follicle-like structures but, in contrast, spreaded and reached confluency independently of cell proliferation. This effect is suppressed by an RGD-containing peptide. The adhesive properties of thrombospondin-1 for thyroid cells were shown to be mediated by both the amino-terminal heparin-binding domain and the RGD domain of thrombospondin-1. Adhesion was shown to involve (alpha)vbeta3 integrin. The results show that TGF-beta1 exerted an influence upon function and behaviour of follicle cells partly mediated by the synthesis of thrombospondin-1 and of its receptor (alpha)vbeta3 integrin.


Assuntos
Células Epiteliais/efeitos dos fármacos , Trombospondina 1/biossíntese , Glândula Tireoide/efeitos dos fármacos , Tireotropina/farmacologia , Fator de Crescimento Transformador beta/farmacologia , Animais , Adesão Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Células Epiteliais/metabolismo , Receptores de Vitronectina/fisiologia , Suínos , Glândula Tireoide/citologia , Glândula Tireoide/metabolismo
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