RESUMO
Excessive exposure to UV, especially UVB, is the most important risk factor for skin cancer and premature skin aging. The identification of the specialized pro-resolving lipid mediators (SPMs) challenged the preexisting paradigm of how inflammation ends. Rather than a passive process, the resolution of inflammation relies on the active production of SPMs, such as Lipoxins (Lx), Maresins, protectins, and Resolvins. LXA4 is an SPM that exerts its action through ALX/FPR2 receptor. Stable ALX/FPR2 agonists are required because SPMs can be quickly metabolized within tissues near the site of formation. BML-111 is a commercially available synthetic ALX/FPR2 receptor agonist with analgesic, antioxidant, and anti-inflammatory properties. Based on that, we aimed to determine the effect of BML-111 in a model of UVB-induced skin inflammation in hairless mice. We demonstrated that BML-111 ameliorates the signs of UVB-induced skin inflammation by reducing neutrophil recruitment and mast cell activation. Reduction of these cells by BML-111 led to lower number of sunburn cells formation, decrease in epidermal thickness, collagen degradation, cytokine production (TNF-α, IL-1ß, IL-6, TGF, and IL-10), and oxidative stress (observed by an increase in total antioxidant capacity and Nrf2 signaling pathway), indicating that BML-111 might be a promising drug to treat skin disorders.
Assuntos
Dermatite/prevenção & controle , Ácidos Heptanoicos/administração & dosagem , Protetores contra Radiação/administração & dosagem , Receptores de Lipoxinas/antagonistas & inibidores , Animais , Antígenos CD59/metabolismo , Dermatite/etiologia , Dermatite/metabolismo , Modelos Animais de Doenças , Ácidos Docosa-Hexaenoicos/metabolismo , Relação Dose-Resposta a Droga , Ácidos Heptanoicos/farmacologia , Lipoxinas/metabolismo , Camundongos , Camundongos Pelados , Protetores contra Radiação/farmacologia , Raios Ultravioleta/efeitos adversosRESUMO
Complement dysregulation plays a key role in the pathogenesis of age-related macular degeneration (AMD), but the specific mechanisms are incompletely understood. Complement also potentiates retinal degeneration in the murine light damage model. To test the retinal function of CD59a, a complement inhibitor, CD59a knockout (KO) mice were used for light damage (LD) experiments. Retinal degeneration and function were compared in WT versus KO mice following light damage. Gene expression changes, endoplasmic reticulum (ER) stress, and glial cell activation were also compared. At baseline, the ERG responses and rhodopsin levels were lower in CD59aKO compared to wild-type (WT) mice. Following LD, the ERG responses were better preserved in CD59aKO compared to WT mice. Correspondingly, the number of photoreceptors was higher in CD59aKO retinas than WT controls after LD. Under normal light conditions, CD59aKO mice had higher levels than WT for GFAP immunostaining in Müller cells, mRNA and protein levels of two ER-stress markers, and neurotrophic factors. The reduction in photon capture, together with the neurotrophic factor upregulation, may explain the structural and functional protection against LD in the CD59aKO.
Assuntos
Antígenos CD59/genética , Luz , Células Fotorreceptoras de Vertebrados/efeitos da radiação , Degeneração Retiniana/patologia , Animais , Antígenos CD59/metabolismo , Citocinas/genética , Citocinas/metabolismo , Modelos Animais de Doenças , Eletrorretinografia , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático/efeitos da radiação , Células Ependimogliais/metabolismo , Enucleação Ocular , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microscopia de Fluorescência , Fatores de Crescimento Neural/genética , Fatores de Crescimento Neural/metabolismo , Neuroglia/citologia , Neuroglia/metabolismo , Neuroglia/efeitos da radiação , Fagocitose/efeitos da radiação , Células Fotorreceptoras de Vertebrados/metabolismo , RNA Mensageiro/metabolismo , Retina/diagnóstico por imagem , Retina/metabolismo , Degeneração Retiniana/metabolismo , Degeneração Retiniana/veterinária , Retinaldeído/análise , Rodopsina/genética , Rodopsina/metabolismo , Regulação para Cima/efeitos da radiaçãoRESUMO
Although the majority of B cells express surface CD20 in chronic lymphocytic leukaemia (B-CLL), only â¼50% of patients respond to treatment with rituximab. Decreased CD20 expression on these tumour B cells could be responsible for the lack of response observed in some patients treated with rituximab. Despite the potential critical role of CD20 in the biology of B cell malignancies, the mechanisms controlling its expression are poorly understood. At the bone marrow level, mesenchymal stromal cells (MSC) may regulate and support the survival of malignant cells, such as B-CLL cells. In this study, we investigated whether MSC may regulate the CD20 expression on B-CLL. For this purpose, B cells from CLL patients were isolated and co-cultured on MSC. B-CLL cells were collected from B-CLL/MSC co-cultures and examined for their expression of CD20. We demonstrate decreased CD20 expression in B-CLL cells after 2 weeks of co-culture with MSC, under contact and non-contact conditions, which was associated with a decreased susceptibility to rituximab. Additionally, B cells co-cultured with MSCs show an increase in CD59 expression. Our findings strongly suggest that the interaction between B-CLL cells and MSC may play a major role in the resistance to rituximab-induced apoptosis of B-CLL cells.
Assuntos
Antígenos CD20/metabolismo , Leucemia Linfocítica Crônica de Células B/metabolismo , Células-Tronco Mesenquimais/metabolismo , Anticorpos Monoclonais Murinos/farmacologia , Anticorpos Monoclonais Murinos/uso terapêutico , Citotoxicidade Celular Dependente de Anticorpos/imunologia , Antígenos CD20/genética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose , Antígenos CD59/genética , Antígenos CD59/metabolismo , Comunicação Celular , Técnicas de Cocultura , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos/genética , Expressão Gênica , Humanos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/genética , Células-Tronco Mesenquimais/efeitos dos fármacos , RituximabRESUMO
The control of complement activation in the embryo-maternal environment has been demonstrated to be critical for embryo survival. Complement proteins are expressed in the human endometrium; however, the modulation of this expression by embryo signals has not been explored. To assess the expression of complement proteins in response to human chorionic gonadotropin (hCG), we designed an experimental study using in vivo and in vitro models. Twelve fertile women were treated with hCG or left untreated during the mid-luteal phase, and an endometrial biopsy was performed 24 hours later. The localizations of C3, membrane cofactor protein (MCP; CD46), decay-accelerating factor (DAF; CD55), and protectin (CD59) were assessed by immunohistochemistry, and the messenger RNA (mRNA) levels of these proteins were quantified by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) in cells harvested from endometrial compartments using laser capture microdissection. Endometrial explants were cultured with or without hCG for 24 hours, and the C3 and DAF protein levels were measured by Western blotting. Elevated C3 mRNA levels in stromal cells and elevated DAF levels in epithelial luminal cells were detected after hCG treatment. In the endometrial explant model, the progesterone receptor antagonist RU486 inhibited the increases in the levels of C3 and DAF in response to hCG. The findings of this study indicate that hCG plays a role in embryo-endometrium communication and affects the expression of complement proteins in endometrial compartments during the implantation window.
Assuntos
Antígenos CD55/metabolismo , Gonadotropina Coriônica/administração & dosagem , Complemento C3/metabolismo , Implantação do Embrião/efeitos dos fármacos , Endométrio/efeitos dos fármacos , Adulto , Antígenos CD55/genética , Antígenos CD59/genética , Antígenos CD59/metabolismo , Complemento C3/genética , Endométrio/imunologia , Endométrio/metabolismo , Feminino , Antagonistas de Hormônios/farmacologia , Humanos , Ciclo Menstrual/imunologia , Ciclo Menstrual/metabolismo , Mifepristona/farmacologia , RNA Mensageiro/metabolismo , Receptores de Progesterona/efeitos dos fármacos , Receptores de Progesterona/metabolismo , Fatores de Tempo , Técnicas de Cultura de TecidosRESUMO
CD55, CD59, CD46, and CD35 are proteins with complement regulatory (Creg) properties that ensure cell and tissue integrity when this system is activated. The aim of this study was to evaluate the Creg expression on peripheral blood cells from SLE patients and its association with cytopenia and disease activity. Flow cytometric analyses were performed on blood cells from 100 SLE patients and 61 healthy controls. Compared with healthy controls, we observed in SLE patients with lymphopenia and neutropenia decreased expression of CD55, CD59, and CD46 (P < 0.05). In SLE patients with anemia, CD59 and CD35 were decreased on red blood cells. Furthermore, there was a negative correlation between CD55 and CD59 on neutrophils and the disease activity. The results suggest there is an altered pattern of Creg expression on the peripheral blood cells of SLE patients, and the expression is correlated with disease activity and/or with activation of the complement system.
Assuntos
Antígenos CD/metabolismo , Células Sanguíneas/metabolismo , Proteínas do Sistema Complemento/metabolismo , Lúpus Eritematoso Sistêmico/metabolismo , Adulto , Células Sanguíneas/imunologia , Antígenos CD55/metabolismo , Antígenos CD59/metabolismo , Proteínas do Sistema Complemento/imunologia , Eritrócitos/metabolismo , Feminino , Humanos , Imunofenotipagem , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Proteína Cofatora de Membrana/metabolismo , Pessoa de Meia-Idade , Monócitos/metabolismo , Neutrófilos/metabolismo , Receptores de Complemento 3b/metabolismoRESUMO
The present study describes the temporal expression of complement regulatory molecules membrane cofactor protein (MCP), decay accelerating factor (DAF), CR1, and CD59 in the human endometrium throughout the normal menstrual cycle and in patients submitted to ovarian hyperstimulation. During its proliferative phase, the endometrium expresses MCP, with increased expression during the secretory phase. Phase-dependent expression also was observed for DAF and CD59, mainly in the secretory phase. Expression of CR1 was not detected. These results suggest the presence of complement system activity during the menstrual cycle, with greater expression of regulatory molecules during the secretory phase to protect the epithelial integrity of human endometrium.
Assuntos
Antígenos CD55/metabolismo , Antígenos CD59/metabolismo , Proteínas do Sistema Complemento/metabolismo , Proteína Cofatora de Membrana/metabolismo , Ciclo Menstrual/metabolismo , Indução da Ovulação , Receptores de Complemento 3b/metabolismo , Adulto , Feminino , Expressão Gênica , Humanos , Ovulação/metabolismoRESUMO
In this study we have optimised the enzyme immunoassay (ELISA) to quantify CD59 antigen in human serum or plasma. The glycosyl-phosphatidylinositol (GPI)-linked form of CD59 is known to complex with serum high-density lipoprotein. For ELISA optimisation, therefore, we investigated the effect of detergents, added to the sample diluent, on the determined values of CD59. Values obtained in the presence of octyl-glucoside (OG) for 20 adults aged 18-35 years and 17 children 1-5 years old were, respectively, 33-119 ng/ml (mean +/- S.D.: 66+/-22 ng/ml) and 37-143 ng/ml (76+/-33 ng/ml). These results were higher than those measured without OG and were in contrast with published results showing absence, or eight to nine times lower levels, of the protein in serum. A known range for serum concentrations of CD59 in healthy individuals will establish an important reference point for clinical work and for the investigation of diseases involving the complement membrane attack complex (MAC) and its regulation.