RESUMO
Autoreactive B cells and plasma cells appear to be of central importance in the pathogenesis of systemic lupus erythematosus (SLE) characterized by a plethora of autoantibodies. Recent insights into abnormalities of B cell and plasma cell compartments in human SLE have identified a number of cellular disturbances within these compartments that in part correlate with the disease activity. This review discusses these findings and the potential underlying extrinsic and/or intrinsic influences apparently driving general B cell activation in this entity.
Assuntos
Autoanticorpos/imunologia , Linfócitos B/citologia , Linfócitos B/imunologia , Lúpus Eritematoso Sistêmico/imunologia , HumanosRESUMO
Cartilage-specific extracellular matrix synthesis is the prerequisite for chondrocyte survival and cartilage function, but is affected by the pro-inflammatory cytokine TNF-alpha in arthritis. The aim of the present study was to characterize whether the immunoregulatory cytokine IL-10 might modulate cartilage matrix and cytokine expression in response to TNF-alpha. Primary human articular chondrocytes were treated with either recombinant IL-10, TNF-alpha or a combination of both (at 10ng/mL each) or transduced with an adenoviral vector overexpressing human IL-10 and subsequently stimulated with 10ng/ml TNF-alpha for 6 or 24h. The effects of IL-10 on the cartilage-specific matrix proteins collagen type II, aggrecan, matrix-metalloproteinases (MMP)-3, -13 and pro-inflammatory cytokines were evaluated by real-time RT-PCR and immunohistochemistry. Transduced chondrocytes overexpressed high levels of IL-10 which significantly up-regulated collagen type II expression. TNF-alpha suppressed collagen type II and aggrecan, but increased MMP and cytokine expression in chondrocytes compared to the non-stimulated controls. The TNF-alpha mediated down-regulation of aggrecan expression was significantly antagonized by IL-10 overexpression, whereas the suppression of collagen type II was barely affected. The MMP-13 and IL-1beta expression by TNF-alpha was slightly reduced by IL-10. These results suggest that IL-10 overexpression modulates some catabolic features of TNF-alpha in chondrocytes.
Assuntos
Condrócitos/efeitos dos fármacos , Condrócitos/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Glicoproteínas/metabolismo , Interleucina-10/metabolismo , Adenoviridae/genética , Adenoviridae/metabolismo , Idoso , Idoso de 80 Anos ou mais , Artérias/metabolismo , Proteína de Matriz Oligomérica de Cartilagem , Células Cultivadas , Condrócitos/ultraestrutura , Colágeno Tipo II/genética , Colágeno Tipo II/metabolismo , Proteínas da Matriz Extracelular/genética , Vetores Genéticos/genética , Glicoproteínas/genética , Humanos , Interleucina-10/genética , Proteínas Matrilinas , Metaloproteinase 13 da Matriz/genética , Metaloproteinase 13 da Matriz/metabolismo , Metaloproteinase 3 da Matriz/genética , Metaloproteinase 3 da Matriz/metabolismo , Microscopia Eletrônica de Transmissão , Pessoa de Meia-Idade , RNA Mensageiro/genética , Fator de Necrose Tumoral alfaRESUMO
OBJECTIVE: Multiply traumatised patients often suffer from blood loss and from subsequent therapy-resistant anaemia, possibly mediated by apoptosis, necrosis, or humoral factors. Therefore, the underlying mechanisms were investigated in bone marrow (BM) and peripheral blood in a murine resuscitated haemorrhagic shock (HS) model. METHODS: In healthy male mice, pressure-controlled HS was induced for 60 min. The BM was analysed for Annexin-V, 7-amino-actinomycin D, apoptotic enzymes (caspases-3/7, -8, and -9), expression of death receptors (CD120a, CD95), mitochondrial proteins (Bax, Bcl-2, Bcl-x), as well as erythropoietin (EPO) receptor (EPO-R). Blood cell count, peripheral EPO, and tumour necrosis factor-alpha response were additionally monitored. RESULTS: Twenty-four and 72 h after HS, EPO and EPO-R were strongly up-regulated in peripheral blood and BM, respectively. Decreasing numbers of erythroid progenitors in BM after HS correlated with significant apoptotic changes confirmed by increased caspases-3/7, -8, -9 activity in total BM, death receptor CD95 and CD120a expression on erythroid progenitors, and down-regulated mitochondrial Bcl-2 expression in total BM. Erythroid progenitors in peripheral blood were found to be increased after 72 h. CONCLUSION: Despite the massive EPO response and up-regulation of EPO-R, BM erythroblasts (EBs) decreased. This could be due to deficient maturation of erythroid progenitors. Furthermore, the increased intrinsic and extrinsic apoptosis activation suggests programmed death of erythroid progenitors. We propose that both apoptosis and negatively regulated erythropoiesis contribute to BM dysfunction, while erythroid progenitor egress plays an additional role.
Assuntos
Apoptose/fisiologia , Células Precursoras Eritroides/metabolismo , Eritropoetina/metabolismo , Receptores da Eritropoetina/metabolismo , Choque Hemorrágico/metabolismo , Análise de Variância , Animais , Anexina A5/análise , Apoptose/genética , Inibidores de Caspase , Caspases/metabolismo , Proliferação de Células , Modelos Animais de Doenças , Células Precursoras Eritroides/citologia , Eritropoese/genética , Eritropoese/fisiologia , Eritropoetina/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Choque Hemorrágico/fisiopatologia , Fatores de Tempo , Fator de Necrose Tumoral alfa/fisiologiaRESUMO
The aim of this study is to determine if there is an antagonistic effect between tumour necrosis factor (TNF)-alpha and the immunoregulatory interleukin (IL)-10 on chondrocytes survival. Serum-starved primary human articular chondrocytes were stimulated with either 10 ng/ml recombinant TNF-alpha, IL-10 or a combination of both (at 10 ng/ml each). Chondrocyte apoptosis was determined by measuring caspase-3/7, -8 and -9 activities using caspase assays. Mitochondrial apoptotic inducer bax, and the suppressor bcl-2 were evaluated using western blotting at 48 h. Results indicated that TNF-alpha increased caspase activities and resulted in a significant (p = 0.001) increase in bax/bcl-2 ratio. Stimulation with IL-10 did not alter caspase activities, while co-treatment with IL-10 and TNF-alpha inhibited TNF-alpha induced caspase activities and significantly (p > 0.004) impaired bax/bcl-2 ratio. At 24 h, mRNA levels for collagen type II, TNF-alpha and IL-10 were determined using real-time RT-PCR. Stimulation with TNF-alpha or TNF-alpha and IL-10 significantly inhibited collagen type II and increased IL-10 and TNF-alpha mRNA expression. IL-10 modulated the pro-apoptotic capacity of TNF-alpha in chondrocytes as shown by the decrease in caspase activities and bax/bcl-2 ratio compared to TNF-alpha stimulated chondrocytes, suggesting a mostly antagonistic interplay of IL-10 and TNF-alpha on mitochondrial apoptotic pathways.
