RESUMEN
Background The abnormal biological activity of cytokines plays an important role in the pathophysiology of both systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). Several studies have highlighted the association of vitamin D and certain pro-inflammatory cytokines with disease activity in SLE. However, there are limited data on the association of vitamin D and antiphospholipid antibodies (aPL) with various proinflammatory biomarkers in these patients and their relative impact on clinical outcomes. Methods The serum levels of several aPL, 25-hydroxy-vitamin D, pro-inflammatory cytokines including IFNα, IL-1ß, IL-6, IL-8, IP10, sCD40L, TNFα and VEGF were measured in 312 SLE patients from the Jamaican ( n = 45) and Hopkins ( n = 267) lupus cohorts using commercial Milliplex and ELISA assays. Oxidized LDL/ß2glycoprotein antigenic complexes (oxLß2Ag) and their associated antibodies were also measured in the Jamaican cohort. Healthy controls for oxidative marker and cytokine testing were used. Results Abnormally low vitamin D levels were present in 61.4% and 73.3% of Hopkins and Jamaican SLE patients, respectively. Median concentrations of IP10, TNFα, sCD40L and VEGF were elevated in both cohorts, oxLß2Ag and IL-6 were elevated in the Jamaican cohort, and IFNα, IL-1ß and IL-8 were the same or lower in both cohorts compared to controls. IP10 and VEGF were independent predictors of disease activity, aPL, IP10 and IL-6 were independent predictors of thrombosis and IL-8, and low vitamin D were independent predictors of pregnancy morbidity despite there being no association of vitamin D with pro-inflammatory cytokines. Conclusions Our results indicate that aPL-mediated pro-inflammatory cytokine production is likely a major mechanism of thrombus development in SLE patients. We provide presumptive evidence of the role IL-8 and hypovitaminosis D play in obstetric pathology in SLE but further studies are required to characterize the subtle complexities of vitamin D's relationship with cytokine production and disease activity in these patients.
Asunto(s)
Citocinas/sangre , Lupus Eritematoso Sistémico/fisiopatología , Estrés Oxidativo , Vitamina D/análogos & derivados , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antifosfolípidos/sangre , Biomarcadores/sangre , Estudios de Casos y Controles , Estudios de Cohortes , Ensayo de Inmunoadsorción Enzimática , Femenino , Humanos , Mediadores de Inflamación/sangre , Lupus Eritematoso Sistémico/sangre , Masculino , Persona de Mediana Edad , Trombosis/etiología , Vitamina D/sangre , Adulto JovenRESUMEN
Activation of the complement cascade is an important mechanism for antiphospholipid antibody-mediated thrombosis. We examined the effects of rEV576 (coversin), a recombinant protein inhibitor of complement factor 5 activation, on antiphospholipid antibody-mediated tissue factor up-regulation and thrombosis. Groups of C57BL/6J mice (n=5) received either IgG from a patient with antiphospholipid syndrome (APS) or control IgG from normal human serum (NHS). Each of these groups of mice had IgG administration preceded by either rEV576, or phosphate buffer control. For each of the four treatment groups, the size of induced thrombus, tissue factor activity in carotid homogenates, anticardiolipin and anti-ß2glycoprotein I (anti-ß2GPI) levels were measured 72 h after the first injection. Mice treated with IgG-APS had significantly higher titers of anticardiolipin antibodies and anti-ß2GPI at thrombus induction compared with those treated with IgG-NHS. The IgG-APS/phosphate buffer treatment induced significantly larger thrombi and tissue factor activity compared with other groups. Mice treated with IgG-APS/rEV576 had significantly smaller thrombi and reduced tissue factor activity than those treated with IgG-APS/phosphate buffer. The data confirm involvement of complement activation in antiphospholipid antibody-mediated thrombogenesis and suggest that complement inhibition might ameliorate this effect.
Asunto(s)
Anticuerpos Antifosfolípidos/inmunología , Complemento C5/antagonistas & inhibidores , Trombosis/prevención & control , Animales , Ratones , Ratones Endogámicos C57BL , Proteínas Recombinantes/farmacología , Tromboplastina/análisis , Trombosis/etiología , beta 2 Glicoproteína I/inmunologíaRESUMEN
BACKGROUND: Complement activation plays a role in pathogenesis of the antiphospholipid syndrome (APS), but the involvement of the C5b-9 membrane attack complex (MAC) is unknown. Here we studied the effects of human polyclonal antiphospholipid (aPL) antibodies on thrombosis and tissue factor (TF) up-regulation in C6 deficient (C6(-/-)) mice. METHODS: C6(-/-) mice or the wild-type C3H/HeJ (C6(+/+)) mice were injected twice with IgG-APS (n = 2) or IgM-APS (n = 1) isolated from APS patients or with the corresponding control immunoglobulins (Igs) of normal human serum, (NHS) (IgG-NHS or IgM-NHS). Then, the sizes of induced thrombi in the femoral vein were determined 72 hours after the first injection. Tissue factor was determined in homogenates of carotid arteries and in peritoneal macrophages. RESULTS: Thrombus sizes were significantly larger in C6(+/+) treated with IgG-APS1 or with IgG-APS2 or with IgM-APS when compared with C6(+/+) mice treated with IgG-NHS or with IgM-NHS, respectively. The sizes of thrombi were significantly smaller in the C6(-/-) mice injected with IgG-APS1, IgG-APS2 or IgM-APS (p < 0.001), compared to their C6(+/+) counterparts showing an important abrogation of thrombus formation in mice lacking C6. The TF expression and activity in the C6(-/-) mice treated with IgG-APS or IgM-APS were diminished when compared to C3H/HeJ (C6(+/+)) mice treated with the same Igs. All mice injected with IgG-APS and IgM-APS had medium-high titers of anticardiolipin (aCL) and anti-ß(2)glycoprotein I (aß(2)GPI) antibodies. CONCLUSIONS: These data indicate that the C6 component of the complement system mediates aPL-thrombogenic effects, underscoring an important pathogenic mechanism and indicating the possibility of inhibiting complement to ameliorate APS-related manifestations.
Asunto(s)
Anticuerpos Antifosfolípidos/inmunología , Síndrome Antifosfolípido/inmunología , Complemento C6/genética , Trombofilia/inmunología , Adulto , Animales , Arterias Carótidas/metabolismo , Femenino , Vena Femoral , Humanos , Inmunoglobulina G/inmunología , Inmunoglobulina M/inmunología , Macrófagos Peritoneales/metabolismo , Masculino , Ratones , Ratones Endogámicos C3H , Ratones Noqueados , Persona de Mediana Edad , Tromboplastina/inmunología , Trombosis/inmunología , Trombosis/patología , Regulación hacia Arriba/inmunologíaRESUMEN
SUMMARY OBJECTIVES: In the antiphospholipid syndrome (APS), the immunodominant epitope for the majority of circulating pathogenic antiphospholipid antibodies (aPLs) is the N-terminal domain I (DI) of beta(2)-glycoprotein I. We have previously shown that recombinant DI inhibits the binding of aPLs in fluid phase to immobilized native antigen, and that this inhibition is greater with the DI(D8S/D9G) mutant and absent with the DI(R39S) mutant. Hence, we hypothesized that DI and DI(D8S/D9G) would inhibit aPL-induced pathogenicity in vivo. METHODS: C57BL/6 mice (n = 5, each group) were injected with purified IgG derived from APS patients (IgG-APS, 500 microg) or IgG from normal healthy serum (IgG-NHS) and either recombinant DI, DI(R39S), DI(D8S/D9G), or an irrelevant control peptide (at 10-40 microg). Outcome variables measured were femoral vein thrombus dynamics in treated and control groups following standardized vessel injury, expression of vascular cell adhesion molecule-1 (VCAM-1) on the aortic endothelial surface, and tissue factor (TF) activity in murine macrophages. RESULTS: IgG-APS significantly increased thrombus size as compared with IgG-NHS. The IgG-APS thrombus enhancement effect was abolished in mice pretreated with recombinant DI (P Asunto(s)
Anticuerpos Antifosfolípidos/inmunología
, beta 2 Glicoproteína I/metabolismo
, Animales
, Anticuerpos Antifosfolípidos/fisiología
, Ensayo de Inmunoadsorción Enzimática
, Macrófagos Peritoneales/metabolismo
, Ratones
, Ratones Endogámicos C57BL
, Tromboplastina/metabolismo
, beta 2 Glicoproteína I/química
RESUMEN
It has been shown that endothelial cell (EC) activation and tissue factor (TF) upregulation in EC and monocytes by antiphospholipid antibodies (aPL Abs) leads to a prothrombotic state and involves translocation of nuclear factor-kappa B (NF-kappaB). Here we examined the effects of an NF-kappaB inhibitor on aPL-induced thrombosis, TF activity, and EC in vivo. We treated CD1 mice with IgG from a patient with antiphospholipid syndrome (IgG-APS) or with control IgG (IgG-NHS). The adhesion of leukocytes (number of white blood cells) to EC in cremaster muscle (as an indication of EC activation) as well as the size of an induced thrombus in the femoral vein of the mice were examined. Some mice in each group were infused with 10 microM MG132 (an inhibitor of NF-kappaB). TF activity was determined using a chromogenic assay in homogenates of carotid arteries and in peritoneal cells of mice. In vivo, IgG-APS increased significantly the number of white blood cells adhering to ECs (4.7 +/- 2.2) when compared to control mice (1.5 +/- 0.8), and these effects were significantly reduced when mice were pretreated with MG132 (0.8 +/- 0.2). IgG-APS increased significantly the thrombus size and MG132 inhibited that effect (93%). Treatment of the mice with IgG-APS also induced significantly increased TF function in peritoneal cells and in homogenates of carotid arteries. Pretreatment of the mice with MG132 abrogated those effects significantly. Mice injected with IgG-APS or with IgM-APS with or without the inhibitor had medium-high titers of anticardiolipin antibodies in serum at the time of the surgical procedures. The data show that prothrombotic and proinflammatory properties of IgG-APS and IgM-APS are downregulated in vivo by an NF-kappaB inhibitor. These findings may be important in designing new modalities of targeted therapies to treat thrombosis in patients with APS.
Asunto(s)
Anticuerpos Antifosfolípidos/metabolismo , Adhesión Celular/efectos de los fármacos , Leupeptinas/farmacología , FN-kappa B/antagonistas & inhibidores , Trombosis/metabolismo , Animales , Síndrome Antifosfolípido/sangre , Síndrome Antifosfolípido/inmunología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Humanos , Masculino , Ratones , Persona de Mediana Edad , FN-kappa B/efectos de los fármacos , Tromboplastina/efectos de los fármacosRESUMEN
BACKGROUND: The purpose of this study was to examine whether SB 203580, a p38 mitogen-activated protein kinase (MAPK) inhibitor, is effective in reversing the pathogenic effects of antiphospholipid antibodies. METHODS: The adhesion of THP-1 monocytes to cultured endothelial cells (EC) treated with immunoglobulin G (IgG) from a patient with antiphospholipid syndrome (IgG-APS) or control IgG (IgG-NHS) in the presence and absence of SB 203580 was examined. The size of an induced thrombus in the femoral vein, the adhesion of leukocytes to EC of cremaster muscle, tissue factor (TF) activity in carotid artery and in peritoneal macrophages, the ex vivo expression of vascular cell adhesion molecule-1 (VCAM-1) in aorta preparations and platelet aggregation were studied in mice injected with IgG-APS or control IgG-NHS and with or without SB 203580. RESULTS: SB 203580 significantly reduced the increased adhesion of THP-1 to EC in vitro, the number of leukocytes adhering to EC, the thrombus size, the TF activity in carotid arteries and in peritoneal mononuclear cells, and the expression of VCAM-1 in aorta of mice, and completely abrogated platelet aggregation induced by IgG-APS. CONCLUSION: These data suggest that targeting the p38 MAPK pathway may be valuable in designing new therapy modalities for treating thrombosis in patients with APS.
Asunto(s)
Anticuerpos Antifosfolípidos/inmunología , Endotelio Vascular/metabolismo , Trombosis/enzimología , Trombosis/inmunología , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Adhesión Celular , Células Cultivadas , Endotelio Vascular/citología , Humanos , Imidazoles/farmacología , Leucocitos/citología , Ratones , Activación Plaquetaria , Piridinas/farmacologíaRESUMEN
The fatty acid composition of twelve Bdellovibrio strains isolated upon the growth on bacteria of various taxonomic groups was studied. A dependence of the lipid composition of bdellovibrios on that of bacteria they were parasitizing on was shown. Data pointing to the selective incorporation of fatty acids of host bacteria by bdellovibrios were obtained. Bdellovibrio membranes were shown to contain monounsatured fatty acids with different positions of double bonds indicating that there are at least two alternative mechanisms of synthesis of these acids in the parasites.