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1.
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
2.
Biochim Biophys Acta ; 487(1): 231-42, 1977 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-870056

RESUMO

In pig and sheep thyroid, the arachidonate content of phosphatidylinositol (14.3--17.5%) is much higher than in the other phospholipids. In the thyroid, phosphatidylinositol seems to play an important role in the biosynthesis of prostaglandins. In neutral thyroid lipids, the arachidonate content is much higher in diacylglycerols (15.8%) than in monoacylglycerols (2.9%) or triacylglycerols (4.2%). However, the most important pool of esterified arachidonate is triacylglycerols (1030 nmol of arachidonate/g tissue). Arachidonate represents a very small part of total free fatty acids measured in the presence of albumin and indomethacin (0.65% or 16.4 nmol/g tissue). Thyrotropin (50 munits/ml) causes after 1 h a 2-fold increase in the level of free arachidonate (37.3 nmol/g tissue). Pig thyroid slices rapidly take up [14C]arachidonate and incorporate it into neutral lipids and phospholipids. Specific activity of phosphatidylinositol is 3-fold higher than that of phosphatidylcholine after an hour incubation. Specific activity of diacylglycerols is 8-fold higher than that of triacylglycerols. Thyrotropin (50 munits/ml) causes a significant decrease (32--33%) of incorporation of radioactivity in lipids as compared with standard incubation. This result is compatible with the isotopic dilution of the labeled [14C]arachidonate by nonradioactive arachidonate liberated in the incubation medium under thyrotropin action. Slices and homogenates of pig thyroid weakly convert [14C]arachidonate to prostaglandins E2 and F2alpha (1--2%. Thyrotropin (50 munits/ml) always diminishes the conversion of radioactivity to prostaglandins as compared with standard incubation. This result is compatible with the above-mentioned hypothesis.


Assuntos
Ácidos Araquidônicos/metabolismo , Lipídeos/biossíntese , Prostaglandinas/biossíntese , Glândula Tireoide/metabolismo , Animais , Cromatografia Gasosa , Ácidos Graxos não Esterificados/metabolismo , Glicerídeos/biossíntese , Cinética , Fosfolipídeos/biossíntese , Prostaglandinas E/biossíntese , Prostaglandinas F/biossíntese , Suínos
3.
Biochim Biophys Acta ; 710(3): 359-69, 1982 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-6280773

RESUMO

The 32P incorporation into phospholipids of isolated porcine thyroid cells, cultured for 1-4 days, has been studied in subsequent 2-h incubations. Along with culture ageing, decreased 32P incorporation into total phospholipid of control cells was observed. The presence of 40 munits/ml TSH during the 2 h incubation yielded a relative increase in labelling of phosphatidylinositol, named 'acute phospholipid effect'. A chronic treatment of the cells with TSH concentration ranging from 0.1 to 10 munits/ml ensured the maintenance of a high turnover rate of total phospholipids. The analysis of individual phospholipids revealed that 1-day culture cells in the presence of 0.1 munits/ml TSH presented a strong increase of phosphatidylinositol labelling. This 'chronic phospholipid effect' of TSH can be reproduced by a chronic treatment with dibutyryl cyclic AMP (10(-3)M) or prostaglandin E2 (10(-6)M), which did not evoke a classical phospholipid effect in a 2 h incubation. If TSH (40 munits/ml) is added to the cells in a 2 h incubation, control cells show the classical phospholipid effect whereas cells chronically treated with TSH, dibutyryl cyclic AMP or prostaglandin E2 presented a 'reverse phospholipid effect' i.e. a relative decrease in phosphatidylinositol labelling. 10(-4)M cycloheximide presence during the last 12 h of culture prevented the establishment of the 'chronic phospholipid effect' and of its consequence, 'the reverse phospholipid effect'. On the basis of these results a scheme is proposed in keeping with current hypotheses concerning phosphatidylinositol metabolism.


Assuntos
Fosfatidilinositóis/metabolismo , Glândula Tireoide/metabolismo , Animais , Bucladesina/farmacologia , Células Cultivadas , AMP Cíclico/metabolismo , Dinoprosta , Dinoprostona , Cinética , Prostaglandinas E/farmacologia , Prostaglandinas F/farmacologia , Suínos , Glândula Tireoide/efeitos dos fármacos , Tireotropina/farmacologia
4.
Cell Signal ; 9(1): 41-6, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9067628

RESUMO

In this work, we show that erythropoietin and inositolphosphate-glycan activate Raf-1 and the mitogen-activated protein kinases (MAP kinases) in normal erythropoietin-responsive cells. Using a protein kinase C (PKC) activator such as the phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate and the PKC inhibitor GF109203X, we investigated a possible involvement of PKC during activation of Raf-1 and MAP kinase by erythropoietin or inositolphosphate-glycan. We found that erythropoietin increased MAP kinase level with a maximum stimulation reached at 5-10 min. Inositolphosphate-glycan and 12-O-tetradecanoyl-phorbol-13-acetate increased MAP kinase activity in the same manner. This activity was inhibited by cell preincubation with GF109203X. Two MAP kinase isoforms were present in erythroid progenitor cells, the 44 and 42 kDa proteins. We report here that erythropoietin, inositolphosphate-glycan, and 12-O-tetradecanoyl-phorbol-13-acetate activated only the p44 form (erk-1) of MAP kinase and the Raf-1 protein. GF109203X was used at a concentration which inhibited by 50% erythroid colonie (CFU-E) proliferation and differentiation induced by erythropoietin or inositolphosphate-glycan. These results support the hypothesis that erythropoietin and inositolphosphate-glycan activate Raf-1 and MAP kinases in normal erythroid progenitor cells and suggest that this activation involves PKC.


Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Eritropoetina/farmacologia , Fosfatos de Inositol/farmacologia , Polissacarídeos/farmacologia , Proteína Quinase C/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Diferenciação Celular , Divisão Celular , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Células Precursoras Eritroides/efeitos dos fármacos , Humanos , Indóis/farmacologia , Maleimidas/farmacologia , Proteínas Proto-Oncogênicas c-raf , Coelhos , Ratos
5.
Cell Signal ; 6(5): 513-22, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7818987

RESUMO

In porcine thyroid cell cultures, phospholipid-dependent protein kinases (PKCs) have the same characteristics as intact glands. The overall PKC activity, presence of PKC isozymes, chromatographic pattern and endogenous substrates specificity were not modified during the two-day culture period. Three PKC isozymes (cPKC epsilon, nPKC epsilon and aPKC zeta) were identified by immunoblot analysis in the two subcellular fractions: cytosol and particulate extract, both in intact glands and two-day-old cultures. In cells cultured for two days in the presence of TSH (0.1 mU/ml), the overall PKC activity was stimulated (ca. 200%) in the two compartments. This stimulation was parallel to the increase in protein expression of the three PKC isoforms (as demonstrated by immunoblot analysis) and was accompanied by a redistribution of cPKC alpha and nPKC epsilon toward the particulate fraction. In TSH-treated cells, hydroxyapatite chromatography of cytosolic PKC revealed an additional peak of PKC activity eluted at 195 mM potassium phosphate. Its elution molarity did not correspond to the molarity of any known PKC isozyme, and it did not cross-react with antibodies directed against cPKC isozymes--: alpha, beta, or gamma. When TSH was replaced by forskolin (10(-5) M), identical quantitative and qualitative modifications were obtained, suggesting that, in thyroid cells, the cyclic AMP-dependent regulatory cascade could be involved in the control of PKC isoforms expression by TSH.


Assuntos
Colforsina/farmacologia , Isoenzimas/metabolismo , Proteína Quinase C/metabolismo , Glândula Tireoide/enzimologia , Tireotropina/farmacologia , Animais , Células Cultivadas , Cromatografia por Troca Iônica , AMP Cíclico/metabolismo , Immunoblotting , Isoenzimas/isolamento & purificação , Mimetismo Molecular , Proteína Quinase C/isolamento & purificação , Especificidade por Substrato , Suínos , Glândula Tireoide/citologia , Glândula Tireoide/efeitos dos fármacos
6.
Cell Signal ; 6(5): 523-9, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7818988

RESUMO

The involvement of a glycosylphosphatidylinositol/inositolphosphate glycan (GPI/IPG) system in the erythropoietin (Epo) signal transduction was investigated. Endogenous GPI was evidenced in extracts of normal Epo-responsive cells after incorporation of [3H]glucosamine, [3H]inositol and [32P]orthophosphate. Incubation of these cells with Epo produced a rapid and transient hydrolysis of GPI with parallel release of IPG. IPG production was Epo dose dependent and the maximal effect was obtained with the same concentration of Epo which gave the maximal mitogenic effect, i.e. 1 U/ml. The number and size of erythroid colonies (CFU-E) were increased by the addition of purified rat erythroid IPG to the culture medium, but not to the same extent as with a maximal Epo treatment. Exogenous IPG effect was dose dependent. In the presence of suboptimal Epo concentrations, IPG has been found to potentiate Epo-induced CFU-E growth. These results support the hypothesis that a GPI/IPG based signal transduction system may be involved in Epo-induced cell proliferation.


Assuntos
Células Precursoras Eritroides/metabolismo , Eritropoetina/farmacologia , Glicosilfosfatidilinositóis/metabolismo , Fosfatos de Inositol/farmacologia , Polissacarídeos/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Células Precursoras Eritroides/efeitos dos fármacos , Glucosamina/metabolismo , Hidrólise , Inositol/metabolismo , Fosfatos de Inositol/metabolismo , Fígado/citologia , Fígado/embriologia , Fosfatos/metabolismo , Polissacarídeos/metabolismo , Ratos , Transdução de Sinais
7.
Cell Signal ; 2(1): 21-7, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2176799

RESUMO

The increased turnover of phosphatidylinositol promoted by thyrotropin (TSH) in pig thyroid tissue does not seem to be caused by an increased production of inositol tris-phosphate. We have explored another possibility, the synthesis of an inositol phosphate-glycan (IP-gly). Our results show that thyroid cells in culture produced this substance from a precursor phosphatidylinositol-glycan (Gly-PI). The obtained IP-gly seemed, by its analytical and biological properties, to be identical, or similar, to the previously described insulin mediator.


Assuntos
Fosfatos de Inositol/biossíntese , Polissacarídeos/biossíntese , Sistemas do Segundo Mensageiro/efeitos dos fármacos , Glândula Tireoide/efeitos dos fármacos , Tireotropina/farmacologia , Animais , Células Cultivadas , Colforsina/farmacologia , Fosfatos de Inositol/farmacologia , Insulina/farmacologia , Lipólise/efeitos dos fármacos , Masculino , Lipídeos de Membrana/metabolismo , Fosfatidilinositol 4,5-Difosfato , Fosfatidilinositóis/metabolismo , Fosfolipídeos/metabolismo , Polissacarídeos/farmacologia , Ratos , Ratos Endogâmicos , Suínos , Glândula Tireoide/metabolismo
8.
Cell Signal ; 6(2): 173-80, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8086280

RESUMO

Labelling with [3H]glucosamine was used to prepare a transforming growth factor-beta 1 (TGF-beta 1)-sensitive glycosylphosphatidylinositol (GPI) from monolayer cultures of rabbit articular chondrocytes (RAC), which may be involved in control of the cell cycle. The polar headgroup of this glycosylphosphatidylinositol was generated by both phosphatidylinositol-specific phospholipase C (PI-PLC) and pronase E digestion. The molecule emerged in only one peak on a Dowex AG1-X8 chromatogram, eluted at 0.1 N ammonium formate. In contrast, similar experiments performed on cellular extract from cultures previously labelled with [3H]glucosamine displayed four radioactive peaks eluting at 0.1, 0.2, 0.5 and 1 N ammonium formate, respectively. Evidence that the eluting position of these peaks was dependent on the number of phosphate residues present in each fraction was demonstrated by both [32P]phosphorus labelling and change in the position of alkaline phosphatase-induced shift in elution volume. We also demonstrated that the GPI-derived inositolphosphate glycan (IPG) could be hyperphosphorylated into the cell under the action of a kinase whose activity was enhanced by TGF-beta 1 itself. We have also shown that all of these IPG forms could mimic the TGF-beta-induced increase of DNA replication rate of RAC, with a higher activity for peaks III and IV than peaks I and II.


Assuntos
Fosfatos de Inositol/metabolismo , Polissacarídeos/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo , Animais , Cartilagem Articular/citologia , Cartilagem Articular/metabolismo , Ciclo Celular , Divisão Celular , Células Cultivadas , Cromatografia por Troca Iônica , Replicação do DNA/efeitos dos fármacos , Glucosamina/metabolismo , Glicosilfosfatidilinositóis/metabolismo , Humanos , Fosforilação , Proteínas Quinases/metabolismo , Coelhos
9.
Cell Signal ; 4(2): 219-29, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1319725

RESUMO

We examine the autocrine activity of glycosyl inositol phosphate (InP-gly) on thyroid metabolism. The cAMP accumulation promoted by thyrotropin (TSH) or forskolin was modulated by InP-gly, stimulated by the lowest tested concentration (10(-8) M) and progressively inhibited by higher concentrations. Iodide uptake and iodine organification were decreased in a concentration-dependent manner by InP-gly alone, or in the presence of TSH. The IAP component of pertussis toxin blocked the inhibitory action of InP-gly on cAMP accumulation by reconstituted thyroid follicles (RTF), suggesting the participation of Gi protein. But the same treatment with IAP was without effect on iodine metabolism, suggesting that there is a second target for InP-gly, more distal than Gi protein, or coupled to another G protein which is insensitive to the toxin.


Assuntos
Proteínas de Ligação ao GTP/fisiologia , Fosfatos de Inositol/fisiologia , Toxina Pertussis , Glândula Tireoide/metabolismo , Fatores de Virulência de Bordetella/farmacologia , Animais , Células Cultivadas , Colforsina/farmacologia , AMP Cíclico/metabolismo , Proteínas de Ligação ao GTP/efeitos dos fármacos , Glicosilação/efeitos dos fármacos , Fosfatos de Inositol/biossíntese , Iodetos/metabolismo , Iodo/metabolismo , Cinética , Ligação Proteica , Suínos , Glândula Tireoide/citologia , Tireotropina/farmacologia
10.
Endocrinology ; 137(3): 1007-12, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8603567

RESUMO

Hydrogen peroxide (H2O2) is an essential electron acceptor for thyroid peroxidase-catalyzed iodination and coupling reactions. In the presence of iodide, its production is a limiting step in thyroid hormone biosynthesis. Several studies have demonstrated that the thyroid particulate fraction contains a Ca2+- and NADPH- dependent H@O@ generator (NADPH-O2:oxidoreductase), the so- called thyroid NADPH-oxidase. It has recently been demonstrated that cellular H2O2 release is under the tonic control of TSH in primary cultures of dog thyrocytes. The present study evaluates the effect of TSH on the thyroid NADPH-oxidase and cytochrome c reductase activities, two enzymes believed to be involved on H2O2 generation in the thyroid gland. There was almost no detectable NADPH-dependent H2O2 generator in the membranes of cells grown for 18 h without TSH. But cells grown in the presence of TSH (0.1 mU/ml) had a CA2+- and NADPH-dependent H2O2-generating activity that increased up to the third day in culture, as did the cell iodide organification capacity. This increase was also partially blocked by 12-O-tetradecanoylphorbol 13-acetate and cycloheximide. Forskolin and 8-bromo-cAMP both reproduced the action of TSH on the Ca2+- and NADPH-dependent H2O2 generator. In contrast, the thyroid NADPH-cytochrome c reductase activity in particles from control cells was similar to that of TSH-treated cells and was unaffected by forskolin or 12-O-tetradecanoylphorbol 13-acetate. These results suggest that NADPH-cytochrome c reductase activity is not regulated by TSH and, thus, reinforce the idea that this enzyme is not involved in thyroid H2O2 generation. On the other hand, the Ca2+- and NADPH-dependent H2O2 generator, so-called thyroid NADPH- oxidase, is induced by TSH through the cAMP cascade. Thus, it seems to be another marker of thyroid differentiation, in addition to thyroperoxidase and thyroglobulin, and could play a key role in thyroid hormone production.


Assuntos
Cálcio/metabolismo , Peróxido de Hidrogênio/metabolismo , NADH NADPH Oxirredutases/metabolismo , NADPH Oxidases , Glândula Tireoide/metabolismo , Tireotropina/farmacologia , Animais , Células Cultivadas , NADPH-Ferri-Hemoproteína Redutase , Suínos , Tireotropina/metabolismo
11.
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
12.
FEBS Lett ; 148(2): 281-8, 1982 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-6185361

RESUMO

The arachidonate inhibition of the adenylate-cyclase system of cultured pig thyroid cells was not mediated by cyclooxygenase, lipoxygenase or peroxidase metabolites. Indeed ETYA, an inhibitor of cyclooxygenase and lipoxygenase, and methimazole, an inhibitor of peroxidase and iodination were without effect on the arachidonate inhibition. Moreover the effect of arachidonate was amplified by a combination with ETYA. In 32P incorporation experiments we observed a modification of the labelling of individual phospholipids of cultured pig thyroid cells resulting in a decrease into phosphatidylinositol (PI) and an increase into phosphatidate (PA) of arachidonate and ETYA-treated cells. These results may be explained by an inhibition of CDP-diacylglycerol: inositol transferase and conversely a stimulation of PI specific phospholipase C yielding a decrease in PI and an increase in PA, which inhibits in turn adenylate cyclase activity possibly by Ca2+ translocation.


Assuntos
Ácido 5,8,11,14-Eicosatetrainoico/farmacologia , AMP Cíclico/metabolismo , Ácidos Graxos Insaturados/farmacologia , Ácidos Fosfatídicos/metabolismo , Fosfatidilinositóis/metabolismo , Glândula Tireoide/metabolismo , Tireotropina/farmacologia , 1-Metil-3-Isobutilxantina/farmacologia , Animais , Células Cultivadas , Iodetos/metabolismo , Cinética , Fosfolipídeos/biossíntese , Suínos , Glândula Tireoide/efeitos dos fármacos
13.
FEBS Lett ; 181(2): 390-6, 1985 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-2982667

RESUMO

The respective effects of cholera and Bordetella pertussis toxins were studied in time and concentration dependent experiments, following glycerol and fatty acid release, GTP and cAMP levels. Cholera toxin, after a lag time of 30 min, stimulated linearly GTP and cAMP accumulation and lipolysis (maximal effect: 2-fold increase at 5 micrograms/ml). Pertussis toxin presented a biphasic effect both in time and concentration dependent studies. Up to a maximum reached after 2 h with 1.4 units LPF/ml the stimulation affected GTP (3 fold) and cAMP (7 fold) levels, glycerol and fatty acid release (15 fold). Beyond this, an inhibition occurred, yielding a decrease towards basal values of GTP and cAMP content whereas the glycerol and fatty acid release was stopped. These results, which are the first reporting the fluctuation of the GTP content of intact cells challenged with bacterial toxins, show a close relationship between GTP and cyclic AMP levels and lipolytic activity.


Assuntos
Tecido Adiposo/metabolismo , Toxinas Bacterianas/farmacologia , Toxina da Cólera/farmacologia , AMP Cíclico/metabolismo , Guanosina Trifosfato/metabolismo , Lipólise/efeitos dos fármacos , Animais , Ácidos Graxos não Esterificados/metabolismo , Glicerol/metabolismo , Cinética , Masculino , Toxina Pertussis , Ratos , Ratos Endogâmicos , Fatores de Virulência de Bordetella
14.
FEBS Lett ; 274(1-2): 131-5, 1990 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-2147659

RESUMO

Evidence is obtained for the presence of lipocortin-like proteins in human tracheal gland cells in culture. Using polyclonal antibodies to lipocortin I, indirect immunofluorescence studies demonstrate that lipocortin I is mainly confined to the tracheal gland cell surface. From cell membranes, four Ca2(+)-dependent proteins (35, 40, 45 and 67 kDa) were identified as lipocortin related proteins by using immunoblotting and fluorography following [35S]methionine metabolic labeling experiments. A strong immunoreactivity for the 35 kDa protein was observed. In addition, lipocortin-like proteins with apparent Mr33, 35, 37 and 67 kDa, respectively, were released in the apical culture medium by tracheal gland cells cultured on microporous membrane of a double chamber culture system.


Assuntos
Proteínas de Ligação ao Cálcio/biossíntese , Traqueia/metabolismo , Anexinas , Proteínas de Ligação ao Cálcio/isolamento & purificação , Células Cultivadas , Eletroforese em Gel de Poliacrilamida , Imunofluorescência , Glicoproteínas/biossíntese , Humanos , Cinética , Metionina/metabolismo , Peso Molecular , Mucosa/metabolismo
15.
FEBS Lett ; 286(1-2): 105-9, 1991 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-1650710

RESUMO

In fat-cells, insulin increases synergistically the inhibitory effects of adenosine and prostaglandin E2 on adenylyl cyclase activity. When the endogenous production of these feedback inhibitors is suppressed, insulin is no more active in conditions where glycosyl inositol-phosphate which is a putative mediator of its action, is always efficient. Moreover, glycosyl inositol-phosphate signal is transduced by a G protein sensitive to IAP intoxication.


Assuntos
Toxina Adenilato Ciclase , AMP Cíclico/biossíntese , Proteínas de Ligação ao GTP/metabolismo , Glicolipídeos/fisiologia , Toxina Pertussis , Fosfatidilinositóis/fisiologia , Fatores de Virulência de Bordetella/farmacologia , Adenosina/fisiologia , Tecido Adiposo/citologia , Sequência de Aminoácidos , Animais , Células Cultivadas , Dinoprostona/fisiologia , Proteínas de Ligação ao GTP/efeitos dos fármacos , Glicosilfosfatidilinositóis , Insulina/fisiologia , Masculino , Dados de Sequência Molecular , Ratos , Ratos Endogâmicos , Transdução de Sinais , Suínos
16.
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
17.
FEBS Lett ; 235(1-2): 252-6, 1988 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-2969830

RESUMO

A 32 kDa phospholipase A2 inhibitory protein was isolated from pig thyroid gland after calcium precipitation and fast protein liquid anion-exchange chromatography. SDS-polyacrylamide gel electrophoresis revealed the purity of the protein. The protein activity was assessed by the inhibition of pancreatic phospholipase A2 on [3H]oleic acid-labelled Escherichia coli membranes as substrate and on the prostaglandin E2 production of cultured thyroid cells. The amino acid composition and the isoelectric point were quite similar to those of endonexin previously described in other tissues or cells. The cross-reactivity of a polyclonal antibody against a 32 kDa lipocortin from human peripheral blood mononuclear cells with our thyroidal 32 kDa protein confirmed its lipocortin nature. Before the purification by fast protein liquid chromatography, the Ca2+ pellet contained lipocortin I (35 kDa and its core protein 33 kDa) identified by its cross-reactivity with a polyclonal antibody.


Assuntos
Glicoproteínas/isolamento & purificação , Fosfolipases A/antagonistas & inibidores , Fosfolipases/antagonistas & inibidores , Glândula Tireoide/análise , Aminoácidos/análise , Animais , Anexinas , Cromatografia Líquida de Alta Pressão , Dinoprostona , Eletroforese em Gel de Poliacrilamida , Glicoproteínas/farmacologia , Imunoensaio , Peso Molecular , Fosfolipases A2 , Prostaglandinas E/biossíntese , Suínos , Glândula Tireoide/efeitos dos fármacos , Glândula Tireoide/metabolismo
18.
FEBS Lett ; 258(2): 346-50, 1989 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-2532154

RESUMO

Four proteins of the lipocortin family, lipocortin I (35 kDa), lipocortin II (36 kDa), lipocortin V (32 kDa) and lipocortin VI (67-70 kDa), were identified in the cytosols of 2-day-old cultures of thyroid cells. Only lipocortin I was phosphorylated in vitro in fully differentiated, thyroid stimulating hormone-treated cells (0.1 mU/ml). Protein kinase C was the only kinase activity which phosphorylated lipocortin I. Phosphorylation shifted its pI from 6.9 to 6.6. The in vitro phosphorylation of lipocortin I was impaired in cultures exposed for 2 days to phorbol ester (10(-7) M), although it was present in both the cytosol and the particulate fraction of these cells.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Glicoproteínas/metabolismo , Proteína Quinase C/metabolismo , Glândula Tireoide/metabolismo , Animais , Anexinas , Western Blotting , Proteínas de Ligação ao Cálcio/isolamento & purificação , Células Cultivadas , Citosol/metabolismo , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Peso Molecular , Fosforilação , Suínos , Glândula Tireoide/efeitos dos fármacos , Tireotropina/farmacologia
19.
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
20.
Biochimie ; 61(8): 905-12, 1979.
Artigo em Inglês | MEDLINE | ID: mdl-118772

RESUMO

The "phospholipid effect" which is the enhanced turnover of the phosphorylinositol group of phosphatidylinositol (PI) occurs in the thyroid of response to thyreostimulin (TSH). The possibility that Ca2+ ions are involved in this stimulation has been investigated with pig thyroid slices. Experiments performed in media without Ca2+ or containing E.G.T.A. (2 mM), indicate that it is not the extracellular Ca2+ which is implied, but rather the intracellular Ca2+. The ionophore A23187 (6.10(-6) M) increases the specific radioactivity of the acid soluble precursors, but has also a specific effect on the PI turnover, which is additive with the effect of a high concentration of TSH (50 mU/ml). Washing and loading of slices with various Ca2+ concentrations show that 0.9 mM restores the TSH phospholipid effect. Verapamil (10(-3) M) and Chlorpromazine (10(-3) M) redirect glycerolipid metabolism by increasing PI and phosphatidic acid (PA) synthesis at the expense of other glycerolipids, as phosphatidylcholine (PC) and phosphatidylethanolamine (PE). These results suggest that the "phospholipid effect" is not a result of Ca2+ entry into the thyroid cells. On the contrary, it seems that this increased turnover of PI in "long term" incubations (3 hr). An additive and acute effect of TSH effect is more pronounced when Ca2+ movements


Assuntos
Cálcio/fisiologia , Fosfatidilinositóis/metabolismo , Glândula Tireoide/metabolismo , Animais , Calcimicina/farmacologia , Cálcio/farmacologia , Bovinos , Clorpromazina/farmacologia , Ácido Edético/farmacologia , Ácido Egtázico/farmacologia , Técnicas In Vitro , Suínos , Glândula Tireoide/efeitos dos fármacos , Tireotropina/farmacologia , Verapamil/farmacologia
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