RESUMO
Systemic sclerosis (SSc) is a chronic disease, with early activation of the immune system. The aim of our work was to address how SSc-mesenchymal stem cells (MSCs), although senescent, might preserve specific immunomodulatory abilities during SSc. MSCs were obtained from 10 SSc patients and 10 healthy controls (HC). Senescence was evaluated by assessing cell cycle, ß-galactosidase (ß-Gal) activity, p21 and p53 expression; doxorubicin was used as acute senescence stimulus to evaluate their ability to react in stressed conditions. Immunomodulatory abilities were studied co-culturing MSCs with peripheral blood mononuclear cells (PBMCs) and CD4(+) cells, in order to establish both their ability to block proliferation in mixed lymphocyte reaction and in regulatory T cells (Tregs) induction. SSc-MSC showed an increase of senescence biomarkers. Eighty per cent of MSCs were in G0-G1 phase, without significant differences between SSc and HC. SSc-MSCs showed an increased positive ß-Gal staining and higher p21 transcript level compared to HC cells. After doxorubicin, ß-Gal staining increased significantly in SSc-MSCs. On the contrary, doxorubicin abolished p21 activation and elicited p53 induction both in SSc- and HC-MSCs. Interleukin (IL)-6 and transforming growth factor (TGF)-ß-related transcripts and their protein levels were significantly higher in SSc-MSCs. The latter maintained their immunosuppressive effect on lymphocyte proliferation and induced a functionally regulatory phenotype on T cells, increasing surface expression of CD69 and restoring the regulatory function which is impaired in SSc. Increased activation of the IL-6 pathway observed in our cells might represent an adaptive mechanism to senescence, but preserving some specific cellular functions, including immunosuppression.
Assuntos
Células-Tronco Mesenquimais/imunologia , Escleroderma Sistêmico/imunologia , Linfócitos T Reguladores/imunologia , Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Proliferação de Células/efeitos dos fármacos , Terapia Baseada em Transplante de Células e Tecidos , Células Cultivadas , Senescência Celular/efeitos dos fármacos , Senescência Celular/imunologia , Técnicas de Cocultura , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Doxorrubicina/farmacologia , Humanos , Imunomodulação , Interleucina-6/genética , Interleucina-6/metabolismo , Lectinas Tipo C/metabolismo , Escleroderma Sistêmico/terapia , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Proteína Supressora de Tumor p53/metabolismo , beta-Galactosidase/metabolismoRESUMO
Basic helix-loop-helix (bHLH) transcription factors are involved in neuroendocrine cell growth and differentiation. Though NeuroD1 is viewed as corticotroph specific, its overexpression in non-corticotroph pituitary adenomas (PAs) may reflect the activation of molecular pathways involving other bHLH factors, like neurogenins. To search for neurogenin-NeuroD1 molecular pathways in the human normal and tumoural pituitary. Fifty-one PAs--22 clinically non-secreting (CNS) and 29 secreting respectively--and normal human pituitaries (NP) were studied for NeuroD1 and neurogenins (Ngn1, Ngn2 and Ngn3) gene expression by RT-PCR and quantitative real-time RT-PCR (qRT-PCR). Immunohistochemistry for Ngn2/3 was performed in some cases. NeuroD1, Ngn2, Ngn3 and Ngn1 were observed in up to 84.3, 76.5, 30.4 and 9.1% of PA respectively, only NeuroD1 and Ngn2 being frequently overexpressed when compared with NP. Whereas NeuroD1 expression was higher in corticotroph and CNS adenomas (P=0.0001 versus Pit-1-dependent PA), Ngn2 expression was higher in secreting PA, especially in Pit-1-dependent PA (P=0.007 and P=0.0006 versus CNS respectively). Pit-1-dependent PA which received pre-operative pharmacological treatment expressed higher Ngn2 levels than untreated cases (P=0.025). Nuclear Ngn2 was observed in NP and in most PA, especially ACTH- and GH-secreting adenomas. Nuclear Ngn3 was observed in a minority of secreting PA. Ngn2 is normally expressed in the anterior pituitary and frequently expressed in PA, but does not account for NeuroD1 overexpression where present. Owing to their low and inconstant expression, the biological significance of Ngn1/3 in the adult pituitary is uncertain.
Assuntos
Adenoma/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hipofisárias/metabolismo , Adolescente , Hormônio Adrenocorticotrópico/metabolismo , Adulto , Idoso , Fatores de Transcrição Hélice-Alça-Hélice Básicos/análise , Estudos de Casos e Controles , Distribuição de Qui-Quadrado , Criança , Feminino , Expressão Gênica , Hormônio do Crescimento/metabolismo , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/análise , Proteínas do Tecido Nervoso/genética , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estatísticas não ParamétricasRESUMO
The effects of cadmium (Cd) on phytohemoagglutinin or phorbol myristate acetate-induced lymphocyte activation were investigated and a dose-dependent inhibition of cell proliferation was found. Kinetic studies revealed that the Cd-sensitive step is an early event of T cell stimulation. Failure of IL2 secretion and reduction of IL2 receptor expression in the Cd-treated cells are also reported. Regardless of which mechanism is responsible for Cd effects, our studies show that the inhibition of lymphocyte activation is associated with reduced [3H]phorbol dibutyrate binding to Ca2+-phospholipid-dependent protein kinase and altered breakdown of phosphatidylinositols. Thus, Cd interferes with two biochemical events which play a critical role in lymphocyte signal transduction and activation.
Assuntos
Cádmio/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Adulto , Cloreto de Cádmio , Radioisótopos de Cádmio , Cálcio/farmacologia , Divisão Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Relação Dose-Resposta a Droga , Humanos , Interleucinas/metabolismo , Cinética , Linfócitos/citologia , Linfócitos/efeitos dos fármacos , Linfócitos/fisiologia , Dibutirato de 12,13-Forbol/metabolismo , Fosfatidilinositóis/metabolismo , Fosfolipídeos/farmacologia , Fito-Hemaglutininas/farmacologia , Proteínas Quinases/metabolismo , Receptores de Interleucina-2/metabolismo , Acetato de Tetradecanoilforbol/farmacologiaRESUMO
The intercellular adhesion molecule 1 (ICAM-1) can be induced on many different cell types by a set of various modulators (IL1 beta, TNF, LPS, IFN-gamma), which are released during the inflammatory process. We have investigated the possibility that other factors, related to the stress and biophysical perturbations of the inflammatory response, may also modulate ICAM-1. Here, we report that heavy metals, in particular zinc, can enhance the expression of the ICAM-1 gene on cells actively involved at different levels during inflammation. Kinetic studies of ICAM-1 gene expression shows a maximum level of induction 4 h after treatment with metals, followed by a rapid decrease to basal levels within 12 h. The effect on enhanced gene expression is mostly due to a rapid increase of the transcriptional rate as shown by nuclear run-on experiments. In B lymphoblastoid cells, but not in fibroblasts, the increase in RNA expression seems significantly greater that the subsequent increase in protein expression, suggesting that a further point of post-transcriptional regulation of ICAM-1 occurs and may be linked to the cellular specificity. may be linked to the cellular specificity.
Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Molécula 1 de Adesão Intercelular/biossíntese , Zinco/farmacologia , Cádmio/farmacologia , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Ensaio de Imunoadsorção Enzimática , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Humanos , Molécula 1 de Adesão Intercelular/genética , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/metabolismo , Especificidade de Órgãos , Transcrição Gênica/efeitos dos fármacosRESUMO
BACKGROUND: We evaluated whether angiotensin II (Ang II) influenced intercellular adhesion molecule (ICAM)-1 expression by human vascular endothelial cells derived from umbilical cord veins (HUVECs) and plasma soluble ICAM-1 levels in vivo. METHODS AND RESULTS: Cultured HUVECs were incubated with Ang II (from 10(-9) to 10(-6) mol/L) with or without candesartan and PD12319 (inhibitors of Ang II AT(1) and AT(2) receptors, respectively) for various times up to 4 hours. Total RNA was then extracted from HUVECs, and Northern blots were probed with a 1.9-kb ICAM-1 cDNA fragment. HUVEC supernatants were used to assess soluble ICAM-1 release by ELISA. Northern blot analysis detected a strong increase of ICAM-1 mRNA after 2-hour incubation with Ang II. The response was inhibited by candesartan. Soluble ICAM-1 release by HUVECs also increased (P<0. 002) after 2-hour Ang II stimulation. In vivo, Ang II (at an initial rate of 1.0 ng. kg(-1). min(-1), to be increased each 30 minutes by 2.0 ng. kg(-1). min(-1) to the final rate of 7.0 ng. kg(-1). min(-1)) was infused in 8 normotensive and 12 essential hypertensive individuals. In the latter, Ang II was reinfused after 4 weeks on either placebo (n=3), losartan (50 mg UID, n=5), or atenolol (50 mg UID, n=4) treatment. Plasma soluble ICAM-1 levels increased after Ang II infusion in hypertensives and normotensives (P<0.0001 after 90 minutes). Losartan reduced baseline soluble ICAM-1 levels (P<0.05) and Ang II-related ICAM-1 increments. CONCLUSIONS: Ang II upregulates ICAM-1 expression by HUVECs and stimulates in vitro and in vivo soluble ICAM-1 release. AT(1) receptor blockade inhibits such endothelial effects of Ang II.
Assuntos
Angiotensina II/farmacologia , Endotélio Vascular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Molécula 1 de Adesão Intercelular/biossíntese , Adulto , Antagonistas de Receptores de Angiotensina , Anti-Hipertensivos/farmacologia , Anti-Hipertensivos/uso terapêutico , Atenolol/farmacologia , Células Cultivadas , Endotélio Vascular/citologia , Feminino , Humanos , Hipertensão/metabolismo , Molécula 1 de Adesão Intercelular/genética , Losartan/farmacologia , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/biossíntese , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores de Angiotensina/efeitos dos fármacos , Veias UmbilicaisRESUMO
Ceramide is an intracellular lipid mediator generated through the sphingomyelin cycle in response to several extracellular signals. Ceramide has been shown to induce growth inhibition, c-myc downmodulation and apoptosis. In this paper we examined the mechanism by which ceramide induces growth suppression and the role of the G1-CDK/pRb/E2F pathway in this process. The addition of exogenous, cell-permeable C2-ceramide to the Hs 27 human diploid fibroblast cell line resulted in a dose-dependent induction of the p21WAF1/CIP1/Sdi1 kinase inhibitor with reduction of cyclin-D1 associated kinase activity. Furthermore, significant dephosphorylation of pRb was observed, with increased association of pRb and the E2F transcription factor into a transcriptionally inactive complex. Ceramide was also capable of inhibiting the transcriptional activity of a CAT reporter vector driven by E2F binding sites containing c-myc promoter transfected into Hs 27 cells. The requirement of the pRb protein for ceramide-induced c-myc downregulation was supported by the failure of ceramide to inhibit promoter activity in HeLa cells, in which pRb function is abrogated by the presence of the E7 Papilloma virus oncoprotein, and in pRb-deleted SAOS2 AT cells. Ceramide-induced downregulation of the c-myc promoter was restored in SAOS2 #1 cells in which a functional Rb gene was reintroduced. Our studies demonstrate that pRb dephosphorylation, induced by ceramide, is at least partly necessary for c-myc downregulation, and therefore the CDK-Rb-E2F pathway appears to be a target for the ceramide-induced modulation of cell cycle regulated gene transcription.
Assuntos
Apoptose/efeitos dos fármacos , Apoptose/genética , Proteínas de Transporte , Proteínas de Ciclo Celular , Proteínas de Ligação a DNA , Genes myc/genética , Esfingosina/análogos & derivados , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p21 , Ciclinas/metabolismo , Fatores de Transcrição E2F , Regulação da Expressão Gênica/efeitos dos fármacos , Genes Reporter/genética , Humanos , Fosforilação , Regiões Promotoras Genéticas/genética , Proteína do Retinoblastoma/química , Proteína do Retinoblastoma/metabolismo , Proteína 1 de Ligação ao Retinoblastoma , Esfingosina/farmacologia , Fator de Transcrição DP1 , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo , Transcrição Gênica/efeitos dos fármacos , TransfecçãoRESUMO
The DNA synthesis of lymphocytes triggered by phytohemagglutinin or phorbol-myristate-acetate is strongly reduced by the externally applied electromagnetic field (ELF). Ca2+ uptake by stimulated lymphocytes is also reduced by ELF. The effect appears to be synergistic with that of the well-known calcium blocker agent, verapamil.
Assuntos
Cálcio/metabolismo , Fenômenos Eletromagnéticos , Ativação Linfocitária/efeitos dos fármacos , Humanos , Linfócitos/metabolismo , Fito-Hemaglutininas/farmacologia , Acetato de Tetradecanoilforbol/farmacologia , Timidina/metabolismo , Verapamil/farmacologiaRESUMO
The effects of pulsed extremely low frequency electromagnetic fields on human peripheral blood lymphocyte mitogenesis induced by phytohaemoagglutinin, concanavalin A or calcium ionophore A23187 were studied. The dependence of the field effect on mitogen concentrations was investigated. Field exposure produced strong inhibition of DNA synthesis when optimal doses of mitogens were used, confirming our previous findings. Opposite effects were observed at suboptimal concentration of mitogens. Experiments performed by exposing cell cultures to the field for short periods indicated that a field application of at least 6 h is needed to influence irreversibly lymphocyte blastogenesis.
Assuntos
Calcimicina/farmacologia , Concanavalina A/farmacologia , Campos Eletromagnéticos , Fenômenos Eletromagnéticos , Ativação Linfocitária , Fito-Hemaglutininas/farmacologia , Cálcio/metabolismo , Células Cultivadas , Replicação do DNA/efeitos dos fármacos , Replicação do DNA/efeitos da radiação , Relação Dose-Resposta a Droga , Humanos , Ativação Linfocitária/efeitos dos fármacos , Ativação Linfocitária/efeitos da radiação , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Linfócitos/efeitos da radiação , Fatores de TempoRESUMO
Blastogenesis of human peripheral blood lymphocytes stimulated in vitro by non-specific mitogens (PHA, ConA, PWM) upon exposure to extremely low frequency EMF has been studied. Different frequencies of square waveforms have been used. PHA-stimulation resulted in strong inhibitions as measured by [3H]thymidine incorporation. A frequency window (3-50 Hz) within which ConA-induced blastogenesis was significantly inhibited has been individuated. The mitogenic effect of PWM was significantly affected only at 3 Hz.
Assuntos
Campos Eletromagnéticos , Fenômenos Eletromagnéticos , Lectinas/farmacologia , Ativação Linfocitária , Adulto , Células Cultivadas , Concanavalina A/farmacologia , Humanos , Fito-Hemaglutininas/farmacologia , Mitógenos de Phytolacca americana/farmacologia , Timidina/metabolismoRESUMO
OBJECTIVE: Pituitary adenomas are usually sporadic, although rare familial cases have been described. Here we report two first degree female cousins with giant pituitary adenoma and overweight. Both presented with secondary amenorrhoea, occasional headache and weight gain. MATERIALS AND METHODS: In both patients clinical, morphological and genetic studies were performed. Both patients underwent surgery and post-operative medical therapy with somatostatin analogues and dopamine agonist, followed by a conventional radiotherapy course. RESULTS: Clinical examination at presentation revealed an acromegaloid habitus only in the second patient. Basal and dynamic hormonal evaluation showed high serum GH and serum IGF-I values, higher in the second than in the first patient, and a mild hyperprolactinaemia only in the first patient. On optical and electron microscopy, both tumours were oncocytic adenomas, immunopositive for GH in the first patient and GH/prolactin in the second. The genetic analysis for germ-line mutations of the multiple endocrine neoplasia type 1 gene was negative. Two years after radiotherapy a remarkable shrinkage of both tumours was observed, whereas the overweight worsened in both patients, accompanied by high plasma leptin values. CONCLUSION: To our knowledge, this is the first report of familial pituitary adenomas including one case of a clinically silent GH-secreting adenoma. In addition, it provides further evidence that familial pituitary tumours can occur as a multiple endocrine neoplasia type 1 unrelated disease.
Assuntos
Adenoma/genética , Adenoma/patologia , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/patologia , Aumento de Peso/genética , Adenoma/sangue , Adenoma/terapia , Adulto , Amenorreia/complicações , Antropometria , Análise Mutacional de DNA , Saúde da Família , Feminino , Testes Genéticos , Cefaleia/complicações , Hormônio do Crescimento Humano/sangue , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Leptina/sangue , Imageamento por Ressonância Magnética , Microscopia Eletrônica , Neoplasia Endócrina Múltipla Tipo 1/genética , Mutação/genética , Neoplasias Hipofisárias/sangue , Neoplasias Hipofisárias/terapia , Prolactina/sangueRESUMO
OBJECTIVE: To evaluate the ability of two different combination therapies with prednisone (PDN), methotrexate (MTX) and cyclosporine (CSA) to modulate both TNFalpha transcription and production in early rheumatoid arthritis (RA). METHODS: 24 patients with early RA received a step-down bridge therapy with MTX and PDN (group A). Twelve patients out of the 24 randomly received also CSA (group B). Blood samples and peripheral blood mononuclear cells (PBMC) were collected at different times. TNFalpha levels were measured both in sera and in PBMC supernatants. TNFalpha mRNA was assessed by use of RT-PCR. RESULTS: 10 patients in group A and 9 in group B improved. At baseline, RA patients serum TNFalpha levels were increased compared to controls (p < 0.001) and did not correlate with clinical and serological parameters. These levels decreased within the first month of therapy in both groups, the lower levels being observed in the sera of CSA treated patients. After 30 days of therapy, TNFalpha levels in group B supernatants were significantly lower than those observed in group A, both after 24 and 48 hours of PHA stimulation (p < 0.03 and p < 0.05 respectively). TNFalpha mRNA levels never differed between patients and controls, independently of both the clinical picture and the assigned therapy. CONCLUSION: The addition of CSA to a treatment regimen of PDN + MTX lowers TNFalpha production in vitro without decreasing TNFalpha mRNA expression. This effect could help to induce early immunosoppressive and therapeutic effects during RA.
Assuntos
Antirreumáticos/administração & dosagem , Artrite Reumatoide/tratamento farmacológico , Ciclosporina/administração & dosagem , Metotrexato/administração & dosagem , Fator de Necrose Tumoral alfa/genética , Adulto , Artrite Reumatoide/metabolismo , Células Cultivadas , Quimioterapia Combinada , Feminino , Expressão Gênica/efeitos dos fármacos , Humanos , Técnicas In Vitro , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/metabolismo , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Fator de Necrose Tumoral alfa/metabolismoRESUMO
High concentrations of the non-steroid anti-inflammatory drugs, alone and in association, reduce the blastogenesis of human lymphocytes in vitro. This effect is probably due to the toxicity of these agents and not to the inhibition of prostaglandin (PG) prosuction. Therefore drugs, such as, salicylates and associations of salicylates with other non-steroid anti-inflammatory drugs, which have a weak action on PG-synthesis, also inhibit proliferation of lymphocytes.
Assuntos
Anti-Inflamatórios/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Salicilatos/farmacologia , Aspirina/farmacologia , Diflunisal/farmacologia , Humanos , Técnicas In Vitro , Indometacina/farmacologia , Linfócitos/efeitos dos fármacos , Fito-Hemaglutininas/farmacologia , Antagonistas de Prostaglandina/farmacologia , Salicilato de Sódio/farmacologiaRESUMO
PMN's were cultivated in vitro and treated with supernatants obtained from mitogenic-induced lymphocytes of human tonsil. Cytoplasmic vacuolization increased with time and there was a lower number of neutrophilic clumps in the culture treated with a supernatant containing lymphotoxin. In addition, the PMN's released more thromboxane B2 which was inhibited by indomethacin. We conclude that the action of lymphotoxin on the target PMN's is not mediated by the production of thromboxane B2.
Assuntos
Linfocinas/farmacologia , Neutrófilos/metabolismo , Organoides/metabolismo , Tromboxano B2/biossíntese , Vacúolos/metabolismo , Adulto , Animais , Bovinos , Criança , Humanos , Técnicas In Vitro , Indometacina/farmacologia , Linfócitos/efeitos dos fármacos , Linfotoxina-alfa/metabolismo , Camundongos , Fito-Hemaglutininas/farmacologia , Estimulação Química , Fatores de TempoRESUMO
The authors compare the effect of indomethacin and proglumetacin on the production of prostacyclin in the rat gastric mucosa, and investigate the potential ulcerogenic effect elicited by the two drugs. The results show that indomethacin and proglumetacin, at doses giving similar inhibition of gastric-protacyclin synthesis, drastically differ in their gastric ulcerogenic effects.
Assuntos
6-Cetoprostaglandina F1 alfa/metabolismo , Mucosa Gástrica/metabolismo , Ácidos Indolacéticos/farmacologia , Indometacina/farmacologia , Úlcera Gástrica/induzido quimicamente , Animais , Epoprostenol/metabolismo , Ácidos Indolacéticos/toxicidade , Indometacina/toxicidade , Masculino , Ratos , Ratos EndogâmicosRESUMO
Peritoneal rat macrophages incubated with human recombinant tumour necrosis factor (hrTNF alpha) released 2-3 times more thromboxane (TxB2) than untreated macrophage controls, a result similar to that obtained by incubating them with endotoxin (ET) or calcium ionophore A23187.
Assuntos
Glicoproteínas/farmacologia , Macrófagos/efeitos dos fármacos , Tromboxano B2/metabolismo , Animais , Ácido Araquidônico , Ácidos Araquidônicos/metabolismo , Calcimicina/farmacologia , Macrófagos/metabolismo , Masculino , Ratos , Ratos Endogâmicos , Proteínas Recombinantes/farmacologia , Fator de Necrose Tumoral alfaAssuntos
Ceramidas/análise , Infecções por HIV/imunologia , HIV-1 , Apoptose , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD4-Positivos/patologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Contagem de Células , Humanos , Masculino , Fatores de TempoRESUMO
Cultures of lymphocytes from a patient with a suppressed immune-system were set up, and a low response was seen after treatment with mitogenic substances such as PHA and ConA. Other lymphocyte cultures from the same patient were treated with Levamisole, and after this it was noted that the percentage of T-cell rosettes with sheep erythrocytes was increased.
Assuntos
Síndromes de Imunodeficiência/sangue , Levamisol/farmacologia , Linfócitos/efeitos dos fármacos , Animais , Células Cultivadas , Concanavalina A/farmacologia , Humanos , Linfócitos/metabolismo , Fito-Hemaglutininas/farmacologia , Formação de Roseta , Linfócitos T/metabolismoRESUMO
Macrophages (M phi) and polymorphonuclear leukocytes (PMNs) are cell types that interact with bacterial endotoxin and play key roles in mediating the inflammatory reaction. We examined the ability of rat peritoneal macrophages and human PMNs to synthesize thromboxane A2 (detected as TxB2) in response to human recombinant interleukin 1 (hrIL1). TxB2 levels were measured by radioimmunoassay in the cell-free supernatant of cell suspensions after 1 hr incubation at 37 degrees C. TxB2 release by both PMNs and M phis was increased in a dose-dependent manner by hrIL1.
Assuntos
Interleucina-1/fisiologia , Macrófagos/metabolismo , Neutrófilos/metabolismo , Proteínas Recombinantes/fisiologia , Tromboxano B2/sangue , Animais , Humanos , Masculino , Ratos , Ratos Endogâmicos , Proteínas Recombinantes/farmacologia , Especificidade da EspécieRESUMO
Human peripheral blood polymorphonuclear leukocytes (PMNs) and murine peritoneal macrophages (M phi) were stimulated to generate thromboxane upon treatment with highly purified human interleukin 1/leukocytic pyrogen (IL1/LP) at various concentrations. Thromboxane B2 was measured by radioimmunoassay in the cell-free supernatants of cell suspensions after 1 hour incubation at 37 degrees C. Thromboxane B2 amounts increased in a way which depended on the dose of IL1 added to the cell cultures.
Assuntos
Interleucina-1/farmacologia , Macrófagos/metabolismo , Neutrófilos/metabolismo , Tromboxanos/biossíntese , Animais , Humanos , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos BALB C , Radioimunoensaio , Tromboxano B2/biossínteseRESUMO
The present study involves the determination of the effect of supernatants obtained from mitogen-induced lymphocytes of human tonsils and containing lymphotoxins on human peripheral blood polymorphonuclear leukocytes (PMNs). PMNs treated with supernatants from phytohemagglutinin-stimulated lymphocytes were found to increase the release of thromboxane B2, compared to normal control levels. This increase was blocked by the preincubation of PMNs with indomethacin. The production or increase in production of thromboxanes may be induced by lymphotoxins since these substances have been reported to activate phospholipase A2 in target cell membranes, which may result in release of the thromboxane precursor, arachidonic acid.