RESUMO
Interleukin (IL)-6 is a multifunctional cytokine with a critical role in inflammatory, immunoregulatory and haemopoietic responses. Its receptor consists of an ubiquitously expressed membrane transducing element (gp130) and of the specific element IL-6R-alpha (gp80), present only on hepatocytes and some leukocyte subsets. IL-6R-alpha also exists as soluble protein (sIL-6R) that, in the presence of IL-6, forms a complex able to bind gp130 and, thanks to the mechanism called trans-signaling, transduces IL-6 effect through tyrosine phosphorylation and activation of the signal transducer and transcription activator (STAT)-3. The aim of this study was to analyze the bidirectional relationships between platelet aggregation and IL-6-dependent effects. While platelets do not produce IL-6, we found that resting platelets express gp130, but not gp80, on their membranes. Upon activation by thrombin or calcium ionophore A23187, but not by ADP, the IL-6R-alpha is released in soluble form, while cangrelor, the specific inhibitor of P2Y12 receptor, can partially inhibit sIL-6R release. This sIL-6R is biologically active and, in the presence of IL-6, can trigger IL-6 trans-signaling, inducing an autocrine activation loop (as measured by an increase in gp80 and gp130 content) and STAT3 phosphorylation. On the other hand, IL-6 trans-signaling has no effect on platelet degranulation or aggregation by itself, nor on thrombin-induced platelet aggregation. Our data add an important piece to the puzzle of thrombosis and inflammation: in the presence of IL-6, which can be produced by stressed endothelial cells, the platelet-derived IL-6 trans-signaling could be crucial for the evolution of inflammation within a damaged vessel.
Assuntos
Plaquetas/fisiologia , Interleucina-6/farmacologia , Receptores de Interleucina-6/fisiologia , Transdução de Sinais/fisiologia , Trombina/farmacologia , Difosfato de Adenosina/farmacologia , Plaquetas/efeitos dos fármacos , Calcimicina/farmacologia , Humanos , Agregação Plaquetária/efeitos dos fármacos , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
The skeletal muscles are the major living component of the human body. They are constituted by stable cells, the myofibres, and by adult multipotent stem cells, the satellite cells, which can multiply to regenerate and repair the damaged tissues. Injections of DNA in muscle cells have been used to produce recombinant proteins with opposite goals: somatic reparation of genetic defects, which needs to elicit no inflammatory or immune response, and DNA vaccination, which needs a robust immune response. Because of possible therapeutical interventions, a growing body of information is being produced dealing with every aspect of the myofibres during inflammatory and autoimmune responses: skeletal muscle-antigen presenting cell (APC) interaction and intrinsic APC capabilities of myoblasts and myocytes, the response to released cytokines and their endogenous production, the regulation of Toll-like receptors and major histocompatibility complex expression. According to these data, the muscle tissue is now emerging no longer as a passive bystander, but more as an active player that, when correctly manipulated, can drive tolerance or immunization to these de novo produced proteins. In the present review, we summarize the recent developments on the control of muscle immune function.
Assuntos
Imunidade Ativa , Inflamação/imunologia , Músculo Esquelético/imunologia , Proteínas Aviárias/metabolismo , Citocinas/metabolismo , Técnicas de Transferência de Genes , Humanos , Imunomodulação , Linfócitos T/imunologia , Receptores Toll-Like/fisiologia , Vacinas de DNARESUMO
EBV-associated post transplant lymphoproliferative disease (EBV-PTLD) is a life-threatening complication that may occur after hemopoietic SCT. We prospectively screened 80 children on a weekly basis using nested quantitative PCR to evaluate EBV genome copies. EBV viral load <1000 copies per 10(5) PBMC was observed in 63% of transplants, whereas it was between 1000 and 9999 copies per 10(5) PBMC in 13%, and between 10 000 and 19 999 in 10%, with no significant increase in percentage of CD20+ lymphocytes. Viral load reached > or = 20 000 copies per 10(5) PBMC in 14% of patients, and rituximab was administered to 75% of them. None of the patients except one developed a lymphoproliferative disease. Our study found that only 13% of unrelated donor HSCT recipients had a very high risk of EBV-PTLD defined as > or = 20 000 geq per 10(5) PBMC associated with an increase in CD20+ lymphocyte. We suggest that rituximab could be administered in the presence of very high levels of EBV-DNA viral load or in the presence of mid levels of EBV-DNA viral load associated with an increase in the percentage of CD20+ lymphocytes. Through this approach, we significantly reduced the number of patients treated with rituximab, and consequently the acute and chronic adverse events related to this treatment.
Assuntos
Linfócitos B/patologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Herpesvirus Humano 4/fisiologia , Carga Viral , Ativação Viral , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Murinos , Antígenos CD20 , Criança , Pré-Escolar , DNA Viral/sangue , Feminino , Humanos , Contagem de Linfócitos , Transtornos Linfoproliferativos/etiologia , Transtornos Linfoproliferativos/prevenção & controle , Masculino , Estudos Prospectivos , Rituximab , Transplante HomólogoAssuntos
Predisposição Genética para Doença/genética , Antígenos HLA-DQ/genética , Antígenos de Histocompatibilidade Classe II/genética , Miastenia Gravis/genética , Junção Neuromuscular/genética , Receptores Proteína Tirosina Quinases/genética , Receptores Colinérgicos/genética , Adolescente , Adulto , Idade de Início , Criança , Análise Mutacional de DNA , Feminino , Frequência do Gene , Testes Genéticos , Cadeias alfa de HLA-DQ , Cadeias beta de HLA-DQ , Antígenos HLA-DR/genética , Cadeias HLA-DRB1 , Haplótipos/genética , Humanos , Masculino , Pessoa de Meia-Idade , Miastenia Gravis/imunologia , Miastenia Gravis/metabolismo , Junção Neuromuscular/imunologia , Junção Neuromuscular/metabolismo , Distribuição por Sexo , Adulto JovemRESUMO
The impact of bone marrow (BM) GD2-positive cells on survival has been evaluated in 145 Italian children with localised neuroblastoma (NB) evaluated at diagnosis by anti-GD2 immunocytochemistry. Nineteen of these (13.1%) were found to be BM GD2-positive, with the number of positive cells ranging between 1 and 155 out of 1 x 10(6) total cells analysed. Seven/19 (38.8%) GD2-positive vs 12/126 (9.5%) GD2-negative patients relapsed. The 5-year event-free survival (EFS) and overall survival of the GD2-positive patients was significantly worse than that of the GD2-negative ones (62.2 vs 89.9%, P<0.001; and 74.9 vs 95.9%, P=0.005, respectively). GD2 positivity was not associated to other known risk factors, and in particular to Myc-N amplification and 1p deletion. Among Myc-N-negative patients, the EFS of those negative for both GD2 and 1p deletion was significantly better than in children positive for either one of these two markers (EFS=96.9 vs 66.0%, P<0.001). In conclusion, GD2 positivity may represent a prognostic marker for patients with non-metastatic NB without Myc-N amplification, and its combination with genetic alterations might help identifying patients that require a more careful follow-up.
Assuntos
Células da Medula Óssea/metabolismo , N-Acetilgalactosaminiltransferases/metabolismo , Neuroblastoma/diagnóstico , Neuroblastoma/mortalidade , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/metabolismo , Biópsia por Agulha , Criança , Pré-Escolar , Feminino , Amplificação de Genes , Genes myc , Humanos , Lactente , Recém-Nascido , Masculino , N-Acetilgalactosaminiltransferases/análise , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Prognóstico , Análise de SobrevidaRESUMO
The authors measured anti-muscle-specific tyrosine kinase (anti-MuSK) antibodies (Abs) in 83 serum samples from 40 patients and evaluated their correlation with myasthenia gravis severity and treatment response. Ab concentrations were often reduced by immunosuppression but not after thymectomy. Both in individual cases and in the whole population, a correlation between Ab levels and disease severity was found.
Assuntos
Anticorpos/imunologia , Miastenia Gravis/imunologia , Receptores Proteína Tirosina Quinases/imunologia , Receptores Colinérgicos/imunologia , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Miastenia Gravis/fisiopatologia , Índice de Gravidade de Doença , Estatística como AssuntoRESUMO
OBJECTIVE: To compare the electrophysiological and histopathological features of immunological myasthenia gravis (MG) subtypes. METHODS: Fifty MG patients underwent clinical examination, MuSK-Ab and AChR-Ab analysis. The majority underwent quantitative and single-fiber electromyography (QEMG, SFEMG), repetitive nerve stimulation and deltoid muscle biopsy. From muscle specimens with histological mitochondrial dysfunction, we amplified mitochondrial DNA (mtDNA). In specimens with mtDNA deletions, the nuclear gene POLG1 was sequenced. RESULTS: Five AChR-Ab seropositive [AChR(+)] and 5 seronegative [AChR(-)] patients were MuSK-Ab seropositive [MuSK(+)]. Five of 7 neurophysiologically examined MuSK(+) patients (71%) had proximal myopathic pattern, compared to 7 of 31 MuSK(-)/AChR(+) patients (23%) (P=0.012). SFEMG was abnormal in all examined MuSK(+) patients. All 7 biopsied MuSK(+) and 32 MuSK(-) patients (89%) had cytochrome c oxidase (COX) negative fibers. Three of five MuSK(+) and 13 of 20 MuSK(-) patients analyzed had multiple mtDNA deletions but no POLG1 mutations. CONCLUSIONS: Similar degree of SFEMG abnormalities was present in proximal muscles among MuSK(+) and AChR(+) patients. Proximal myopathy was over-represented in MuSK(+) patients; however, both MuSK(+) and MuSK(-) patients had mild myopathy with frequent mitochondrial abnormalities. SIGNIFICANCE: The weakness in MuSK(+) patients is most likely due to disturbed neuromuscular transmission. The frequently encountered mitochondrial dysfunction in MG warrants further study.
Assuntos
Mitocôndrias Musculares/patologia , Músculo Esquelético , Miastenia Gravis , Receptores Proteína Tirosina Quinases/imunologia , Receptores Colinérgicos/imunologia , Potenciais de Ação/fisiologia , Adulto , Idoso , Anticorpos/metabolismo , Estudos de Casos e Controles , DNA Mitocondrial/genética , Estimulação Elétrica/métodos , Eletromiografia/métodos , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Feminino , Humanos , Imunoglobulinas/metabolismo , Masculino , Pessoa de Meia-Idade , Mitocôndrias Musculares/imunologia , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Fibras Musculares Esqueléticas/fisiologia , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Miastenia Gravis/imunologia , Miastenia Gravis/patologia , Miastenia Gravis/fisiopatologia , Estudos Prospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodosRESUMO
AIMS: To verify the efficiency of Calamintha officinalis essential oil as natural preservative in two current formulations. METHODS AND RESULTS: The 1.0 and 2.0% (v/v) C. officinalis essential oil was assayed for its preservative activity in two product types (cream and shampoo). The microbial challenge test was performed following the standards proposed by the European Pharmacopoeia Commission (E.P.) concerning topical preparations using standard micro-organisms and in addition wild strains, either in single or mixed cultures were used. The results clearly demonstrated that the C. officinalis essential oil at 2.0% concentration reduced the microbial inoculum satisfying the criterion A of the E.P. in the cream formulation and the criterion B in the shampoo formulation. Standard and wild strains showed a behaviour similar, both in cream and in shampoo formulation, with no significant difference (gerarchic variance, P > 0.05). CONCLUSION: C. officinalis essential oil confirmed its preservative properties but at higher concentration than that shown in previous studies on cetomacrogol cream. SIGNIFICANCE AND IMPACT OF THE STUDY: The nature of the formulation in which an essential oil is incorporated as preservative could have considerable effect on its efficacy.
Assuntos
Lamiaceae , Óleos Voláteis , Óleos de Plantas , Conservantes Farmacêuticos , Anti-Infecciosos , Cosméticos , Contaminação de Medicamentos/prevenção & controle , Testes de Sensibilidade Microbiana/métodos , Pomadas , Plantas MedicinaisRESUMO
We studied a well-selected population of patients with active rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) without immunosuppressive therapy. Control and patient peripheral blood mononuclear cells (PBMC) were incubated with IL-1beta, IL-10, TGF-beta or LPS for 20 h and the in vitro basal and stimulated secretions of IL-6, TNF-alpha, IL-1beta and IL-1ra were measured by ELISA. We found that in the SLE patients the basal secretion of IL-6 was significantly lower and that of IL-1ra significantly higher than in control subjects, while in the RA group the basal IL-1ra secretion was higher than in healthy subjects. SLE and RA PBMC responded to LPS and IL-1beta reaching higher cytokine secretion values than controls. The in vitro response of SLE and RA PBMC to TGFbeta was normal, while that to IL-10 was defective: IL-10 was able to stimulate the production of IL-6 and IL-1ra in PBMC from normal subjects, but it was unable to enhance IL-6 secretion in RA cells and it was also completely ineffective in inducing IL-1ra secretion in both SLE and RA PBMC. Our work add new data useful for the evaluation of IL-10 and IL-1ra as therapeutic agents in rheumatic diseases.
Assuntos
Artrite Reumatoide/imunologia , Citocinas/metabolismo , Lúpus Eritematoso Sistêmico/imunologia , Adolescente , Adulto , Anti-Inflamatórios não Esteroides/farmacologia , Estudos de Casos e Controles , Feminino , Humanos , Técnicas In Vitro , Mediadores da Inflamação/farmacologia , Proteína Antagonista do Receptor de Interleucina 1 , Interleucina-1/metabolismo , Interleucina-1/farmacologia , Interleucina-10/farmacologia , Interleucina-6/metabolismo , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Lipopolissacarídeos/farmacologia , Pessoa de Meia-Idade , Proteínas Recombinantes/farmacologia , Sialoglicoproteínas/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Prolactin (PRL) and glucocorticoids are hormones involved in the regulation of the immune system. Rheumatoid arthritis (RA) is an inflammatory condition that presents a diurnal rhythm of disease activity. ACTH, PRL, cortisol, IL-1 beta and TNF-alpha circadian rhythms have been studied in active RA (aRA) to evaluate a possible relationship between the neuroendocrine system and immunological activity in rheumatoid patients. ACTH, PRL, cortisol, PRL/cortisol ratio and IL-1 beta and TNF-alpha levels were determined in aRA patients and in control subjects at 6.00, 10.00, 14.00, 18.00, 22.00 and 02.00 h. In aRA patients we observed lower ACTH and cortisol levels at 22.00 h and 2.00 h, respectively and higher PRL and PRL/cortisol ratio at 2.00 h when compared to controls. IL-1 beta and TNF-alpha reached their highest serum levels in aRA patients at 2.00 and 6.00 h. This study provides evidence that in aRA there could be a temporary and probably causal relationship between diurnal disease activity, hormonal disequilibrium and cytokine secretion. An imbalance in favour of proinflammatory hormones (PRL and cytokines) as opposed to levels of anti-inflammatory hormones could be responsible for the diurnal rhythm of activity disease observed in aRA patients.
Assuntos
Hormônio Adrenocorticotrópico/sangue , Artrite Reumatoide/sangue , Hidrocortisona/sangue , Prolactina/sangue , Artrite Reumatoide/fisiopatologia , Ritmo Circadiano , Regulação para Baixo , Feminino , Humanos , Interleucina-1/sangue , Pessoa de Meia-Idade , Pós-Menopausa , Fator de Necrose Tumoral alfa/análise , Regulação para CimaRESUMO
Anticardiolipin antibodies (aCL) of the immunoglobulin (Ig) G isotype have been significantly associated with neurological manifestations of antiphospholipid syndrome (APS). In a previous study we described the direct pathogenic effects of IgG aCL on living neurons in culture. Therefore, we studied the IgG aCL titre as a factor influencing the extent of this effect. Seventeen patients with a history of primary antiphospholipid syndrome were grouped according to their IgG aCL titre into low positive (GPL < or = 40), high positive (40< GPL <100) and very high positive (GPL >100). IgG from these patients were incubated with cerebellar neurons in primary culture for 24h and the effect was evaluated by using the tetrazolium salt (MTT) assay. We found that almost all patients' IgGs reduced cell viability in vitro, but the differences in the extent of the effect were statistically significant only for patients with >40 GPL. Our results reinforce the causal association between increasing level of IgG aCL and clinical features of aPS.
Assuntos
Anticorpos Anticardiolipina/análise , Síndrome Antifosfolipídica/sangue , Doenças do Sistema Nervoso Central/imunologia , Imunoglobulina G/sangue , Adulto , Análise de Variância , Biomarcadores/análise , Estudos de Casos e Controles , Sobrevivência Celular/imunologia , Sobrevivência Celular/fisiologia , Células Cultivadas , Doenças do Sistema Nervoso Central/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neurônios , Probabilidade , Valores de Referência , Estudos de Amostragem , Sensibilidade e Especificidade , Índice de Gravidade de DoençaRESUMO
OBJECTIVE: To compare secretory immunity in cecal and ileal orthotopic neobladders, and to detect its permanence over time. PATIENTS AND METHODS: IgA was studied in the urine of 33 patients with ileocecourethrostomy (ICUS) and 13 patients with ileal reservoir (IR). The mean follow-up was 55 months. Results were compared in terms of the type of operation, a healthy control group, and the time since surgery. RESULTS: Urinary IgA levels were significantly higher in ICUS and IR patients than in normal controls. No significant differences in IgA concentrations were detected in patients with different reservoirs and with regard to time. CONCLUSION: Both the reservoirs maintain the function of producing IgA. In particular no differences were detected over time and urine could be a permanent antigenic stimulus. IgA could be considered an adjunctive factor for upper urinary tract protection. For this reason we prefer to use a simple, indirect antireflux mechanism, thus avoiding direct manipulation of the uretero-intestinal anastomosis.
Assuntos
Imunoglobulina A Secretora/fisiologia , Coletores de Urina , Idoso , Ceco/cirurgia , Seguimentos , Humanos , Íleo/cirurgia , Masculino , Pessoa de Meia-Idade , Fatores de TempoRESUMO
We studied the expression of MHC-I and MHC-II molecules and ICAM-1 in cultured human myoblasts in response to IL-1beta, IL-4, IL-6, IFN-gamma and LPS. IFN-gamma, LPS and IL-4 greatly increase MHC-I molecule expression. MHC-II molecule expression is induced only by IFN-gamma. Membrane ICAM-1 and mRNA expression are absent under basal conditions, but can be induced by IFN-gamma, IL-1beta, IL-4, LPS and IL-6 with different efficiencies and time-courses. Soluble ICAM-1 secretion can be induced to a different extent by all cytokines. Our study shows that the expression of adhesion-related molecules in muscle is finely regulated by these cytokines.
Assuntos
Citocinas/farmacologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , Músculo Esquelético/metabolismo , Células Cultivadas , Citometria de Fluxo , Humanos , Molécula 1 de Adesão Intercelular/genética , Músculo Esquelético/citologia , RNA Mensageiro/metabolismoRESUMO
Molecular analysis of antigen receptor genes (Ig and TCR) has been useful for clonal studies in acute lymphoblastic leukaemia (ALL) patients. Rearrangements of these genes can be used to track the persistence of the leukaemic clone during the therapy. The purpose of our study was to analyse the percentage and the pattern of the rearrangements at the TCR D locus in a series of ALL patients, comparing the results obtained by Southern blot and PCR. Genomic DNA was extracted from mononuclear BM cells of 40 paediatric ALL cases, digested with different restriction enzymes and hybridized to TCRDJ1 probe to study the TCR delta locus. Amplification of the rearranged TCR delta genes was performed by PCR to define the gene segments involved. The junctional region was deduced from the sequence to obtain patient-specific primers. Among the 31 B lineage ALL samples, one or two TCR delta alleles proved to be rearranged in 53% of cases. Two different types of rearrangements were chiefly detected: Vdelta2Ddelta3 and Ddelta2Ddelta3. In T-ALL patients, the predominant rearrangement involved the Vdelta1 and the Jdelta1 gene segments.
Assuntos
Rearranjo Gênico da Cadeia delta dos Receptores de Antígenos dos Linfócitos T/genética , Leucemia-Linfoma de Células T do Adulto/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Alelos , Sequência de Bases , Southern Blotting , Criança , Pré-Escolar , DNA de Neoplasias/química , DNA de Neoplasias/genética , Feminino , Humanos , Imunofenotipagem , Lactente , Leucemia-Linfoma de Células T do Adulto/imunologia , Masculino , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/genética , Análise de Sequência de DNARESUMO
BACKGROUND AND OBJECTIVE: The feasibility of gene marking or gene therapy protocols making use of purified CD34+ cells greatly depends on the efficiency of their stable transduction. The great potential of umbilical cord blood as a source of CD34+ cells combined with the availability of advanced cell purification procedures prompted us to evaluate whether incubation with growth factors might influence the type of cells effectively transduced by retroviral vectors. DESIGN AND METHODS: Isolated, at least 95% pure, CD34+ cells were infected with the LXSN murine retrovirus carrying the neomycin-resistance gene. Different schedules of CD34+ cell infection were performed with or without incubation for different times in the presence of Interleukin-3 (IL-3), Interleukin-6 (IL-6) and stem cell factor (SCF). Efficiency of transduction was evaluated by clonogenic assays, semiquantitative PCR and RT-PCR analyses performed either immediately or after 7 day expansion of CD34+ cells in liquid culture in the presence of erythropoietin (EPO), IL-3 and granulocyte-macrophage colony-stimulating factor (GM-CSF). RESULTS: The results obtained indicated that the amount of transduced cells increased with the lenght of incubation with growth factors, either before or during infections. However, different types of cells were transduced depending on the duration of stimulation and infection. Thus, following one week culture of CD34+ cells in the presence of EPO, IL-3 and GM-CSF the clonogenic potential was affected dyshomogeneously. Precisely, with a single 3-hour infection performed after 12 hours of stimulation with growth factors, the clonogenic potential of the transduced cells greatly increased after one week in culture. In contrast, with a 48 hour infection, the transduced cells completely lost their clonogenic potential after one week in culture. INTERPRETATION AND CONCLUSIONS: These results demonstrate that a reasonably high transduction efficiency of purified CD34+ cells can be achieved with short schedules of incubation/infection in the absence of stroma or extracellular matrix.
Assuntos
Antígenos CD34/sangue , Ensaio de Unidades Formadoras de Colônias , Sangue Fetal/imunologia , Substâncias de Crescimento/farmacologia , Retroviridae/genética , Transdução Genética , Células Cultivadas , Sangue Fetal/citologia , HumanosRESUMO
Transforming growth factor-beta (TGF-beta) is involved in several autoimmune neurological diseases. It is still unclear whether its local action can be pro-inflammatory or anti-inflammatory in the muscle tissue, because of the few reports on this subject. We have previously shown that human myoblasts secrete interleukin-6 (IL-6) when stimulated with inflammatory cytokine such as interleukin-1beta (IL-1beta) or tumor necrosis factor alpha. In the present report, we show that TGF-beta1 can induce IL-6 production; moreover, costimulation or short term pre-incubation with TGF-beta1 increases IL-1beta effect, while a longer incubation inhibits its action.
Assuntos
Interleucina-6/metabolismo , Músculos/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Sinergismo Farmacológico , Humanos , Interleucina-1/farmacologia , Músculos/citologia , Músculos/efeitos dos fármacos , Fatores de TempoRESUMO
Muscle fibers are the target of T cell-mediated cytotoxic reactions in polymyositis and inclusion body myositis, while the success of myoblast transplantation depends on the absence of an immune rejection against the myofibers. In order to study the behaviour of muscle cells in an inflammatory milieu, we investigated the production of IL-6 and its modulation, including the second messenger pathways controlling it, in in vitro highly purified human myoblast cultures. We found that IL-1beta, tumor necrosis factor (TNF)-alpha and lipopolysaccharide (LPS) stimulated myoblast IL-6 secretion in a dose- and time-dependent manner, whereas forskolin and cholera toxin did not. HA1004 at 10 microM did not significantly affect the IL-1beta- and TNF-alpha-induced IL-6 secretion, suggesting that cAMP and protein kinase A are not sufficient to stimulate this process. To investigate the role of protein kinase C (PKC) in this signal transduction, we employed the inhibitor calphostin C, and the activators phorbol-12-myristate-13-acetate (PMA) and calcium ionophore A23187. Calphostin C blocked IL-6 secretion, PMA had a small stimulatory effect and A23187 had no effect; moreover, PKC down-regulation by PMA did not inhibit IL-1beta stimulation, while it reduced TNF-alpha stimulation. These data indicate that different PKC isoforms may be involved in TNF-alpha and IL-1beta signal transduction. Such a difference can distinguish the action of two traditionally 'overlapping' inflammatory cytokines. Our data suggest that muscle cells, like myoblasts, satellite cells and in vivo regenerating myofibers, may discriminate between different stimuli and produce IL-6 when activated in response to muscle injury.
Assuntos
Inflamação/imunologia , Interleucina-6/biossíntese , Músculos/metabolismo , Adenilil Ciclases/metabolismo , Calcimicina/farmacologia , Células Cultivadas , Humanos , Interleucina-1/farmacologia , Músculos/citologia , Acetato de Tetradecanoilforbol/farmacologia , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
The occurrence and clinical value of anticardiolipin antibodies (aCL) were studied in 33 patients with giant cell arteritis (GCA) and in seven patients with polymyalgia rheumatica (PMR), at onset and during follow-up. aCL were present in 19/40 (47.5%) GCA/PMR cases, most of them of the IgG isotype, whereas all controls (21 subjects) were aCL negative. The presence of aCL was not associated with inflammatory parameters or clinical signs of arteritis; however, they disappeared in a significant percentage (56%) of patients during steroid therapy. No correlation was found between ischaemic events and aCL, suggesting that they are not important for the development of vascular complications in GCA/PMR patients. Moreover, a retrospective evaluation of our data showed a correlation between aCL positivity and anaemia, whose significance remains to be elucidated.