RESUMEN
OBJECTIVES: Systemic vasculitis is a heterogenous group of autoimmune diseases characterized by enhanced cardiovascular mortality. Endothelial dysfunction is associated with accelerated vascular damage, representing a core pathophysiologic mechanism contributing to excess CV risk. Recent studies have also shown that complement activation holds significant role in the pathogenesis of Anti-Neutrophilic Cytoplasmic Autoantibody (ANCA) -associated vasculitis (AAV). Given the potential crosstalk between the endothelium and complement, we aimed to assess, for the first time simultaneously, easily accessible biomarkers of endothelial dysfunction and complement activation in SV. METHODS: We measured circulating endothelial microvesicles (EMVs) and soluble complement components representative of alternative, classical and terminal activation (C5b-9, C1q, Bb fragments, respectively) in a meticulously selected group of patients with systemic vasculitis, but without cardiovascular disease. Individuals free from systemic diseases, who were matched with patients for cardiovascular risk factors(hypertension, diabetes, smoking, dyslipidemia), comprised the control group. RESULTS: We studied 60 individuals (30 in each group). Patients with systemic vasculitis had elevated EMVs, higher levels of C5b-9 [536.4(463.4) vs 1200.94457.3), p = 0.003] and C1q [136.2(146.5 vs 204.2(232.9), p = 0.0129], compared to controls [232.0 (243.5) vs 139.3(52.1), p < 0.001]. In multivariate analysis both EMVs and C5b-9 were independently associated with disease duration (p = 0.005 and p = 0.004 respectively), yet not with disease activity. CONCLUSION: Patients with systemic vasculitis exhibit impaired endothelial function and complement activation, both assessed by easily accessible biomarkers, even in the absence of cardiovascular disease manifestations. EMVs and soluble complement components such as C5b-9 and C1q could be used as early biomarkers of endothelial dysfunction and complement activation, respectively, in clinical practice during the course of SV, yet their predictive value in terms of future cardiovascular disease warrants further verification in appropriately designed studies.
Asunto(s)
Biomarcadores , Activación de Complemento , Endotelio Vascular , Humanos , Masculino , Femenino , Persona de Mediana Edad , Biomarcadores/sangre , Factores de Tiempo , Endotelio Vascular/fisiopatología , Endotelio Vascular/inmunología , Adulto , Anciano , Estudios de Casos y Controles , Micropartículas Derivadas de Células/metabolismo , Micropartículas Derivadas de Células/patología , Micropartículas Derivadas de Células/inmunología , Complejo de Ataque a Membrana del Sistema Complemento/metabolismo , Complejo de Ataque a Membrana del Sistema Complemento/inmunología , Complemento C1q/metabolismo , Complemento C1q/inmunología , Células Endoteliales/patología , Células Endoteliales/inmunología , Células Endoteliales/metabolismo , Vasculitis Sistémica/inmunología , Vasculitis Sistémica/sangre , Vasculitis Sistémica/fisiopatología , Vasculitis Sistémica/diagnósticoRESUMEN
Rather than being mere biomarkers reflecting generalized vascular injury, endothelial- (EMVs) and platelet-derived (PMVs) microvesicles have emerged as potent regulators of intercellular communication with significant biologic effects in vascular homeostasis and several pathophysiological responses including inflammation and thrombosis. So far, studies in hypertension are scarce, whereas no studies exist in masked hypertension (MH). We measured EMVs and PMVs in untreated, newly diagnosed hypertensives (HTs) and MHs compared to normotensive controls (NTs), and associated them with various cardiovascular risk factors. Sustained hypertension (SHT) and MH were defined according to standard blood pressure (BP) criteria. All HTs were free of cardiovascular disease and medications. Microvesicles' quantitation and detection were performed by flow cytometry by using cell-specific antibodies and corresponding isotypes (anti-CD105 and anti-CD144 for EMVs, anti-CD42a for PMVs, and Annexin V-fluorescein isothiocyanate for all microvesicles). In this study, we included 59 HTs (44 SHTs and 15 MHs) and 27 NTs. HTs had significantly elevated EMVs (p = 0.004), but not PMVs compared to NTs. MHs had significantly elevated EMVs compared to NTs (p = 0.012) but not compared to SHTs. Furthermore, EMVs significantly correlated with ambulatory (r = 0.214-0.284), central BP (r = 0.247-0.262), and total vascular resistance (r = 0.327-0.361). EMVs are increased not only in SHTs but also in MHs, a hypertension phenotype with a cardiovascular risk close to SHT. EMVs have emerged as active contributors to thromboinflammation and vascular damage and may explain, in part, the adverse cardiovascular profile of SHTs and MHs.
Asunto(s)
Micropartículas Derivadas de Células , Hipertensión , Trombosis , Humanos , Hipertensión/diagnóstico , Inflamación , FenotipoRESUMEN
BACKGROUND: Acute exercise may exert deleterious effects on the cardiovascular system through a variety of pathophysiological mechanisms, including increased platelet activation. However, the degree of exercise-induced platelet activation in untreated hypertensive (UH) individuals as compared with normotensive (NT) individuals has yet to be established. Furthermore, the effect of antihypertensive treatment on exercise-induced platelet activation in essential hypertension (EH) remains unknown. METHODS: Study 1 consisted of 30 UH and 15 NT subjects. UH subjects who received treatment were included in study 2 and were followed-up after a 3-month treatment period with an angiotensin II receptor blocker (ARB; valsartan). Circulating monocyte-platelet aggregates (MPA) and platelet P-selectin were measured as platelet activation markers at baseline, immediately after a treadmill exercise test, and 10, 30, and 90 minutes later. RESULTS: Maximal platelet activation was observed at 10 minutes after peak exercise in both groups. In UH subjects, MPA levels remained increased at 30 minutes after peak exercise, despite BP fall to baseline levels. MPA levels were significantly higher in UH subjects than NT subjects at maximal exercise and at 10 and 30 minutes of recovery. Post-treatment MPA levels increased significantly only at 10 minutes into recovery and were similar to those of NT subjects. CONCLUSIONS: Acute high-intensity exercise exaggerates platelet activation in untreated patients with EH compared with NT individuals. Angiotensin II receptor blockade with adequate BP control greatly improves exercise-induced platelet activation in EH. Further studies are needed to clarify whether this phenomenon depends purely on BP lowering or benefits also from the pleiotropic effects of ARBs.
Asunto(s)
Antagonistas de Receptores de Angiotensina/uso terapéutico , Ejercicio Físico/fisiología , Hipertensión/fisiopatología , Activación Plaquetaria/efectos de los fármacos , Tetrazoles/uso terapéutico , Valina/análogos & derivados , Adulto , Antihipertensivos/uso terapéutico , Grosor Intima-Media Carotídeo , Hipertensión Esencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valina/uso terapéutico , ValsartánRESUMEN
Indoleamine 2,3-dioxygenase (IDO) suppresses adaptive immunity. T-cell proliferation and differentiation to effector cells require increased glucose consumption, aerobic glycolysis and glutaminolysis. The effect of IDO on the above metabolic pathways was evaluated in alloreactive T-cells. Mixed lymphocyte reaction (MLR) in the presence or not of the IDO inhibitor, 1-methyl-dl-tryptophan (1-MT), was used. In MLRs, 1-MT decreased tryptophan consumption, increased cell proliferation, glucose influx and lactate production, whereas it decreased tricarboxylic acid cycle activity. In T-cells, from the two pathways that could sense tryptophan depletion, i.e. general control nonrepressed 2 (GCN2) kinase and mammalian target of rapamycin complex 1, 1-MT reduced only the activity of the GCN2 kinase. Additionally 1-MT treatment of MLRs altered the expression and/or the phosphorylation state of glucose transporter-1 and of key enzymes involved in glucose metabolism and glutaminolysis in alloreactive T-cells in a way that favors glucose influx, aerobic glycolysis and glutaminolysis. Thus in alloreactive T-cells, IDO through activation of the GCN2 kinase, decreases glucose influx and alters key enzymes involved in metabolism, decreasing aerobic glycolysis and glutaminolysis. Acting in such a way, IDO could be considered as a constraining factor for alloreactive T-cell proliferation and differentiation to effector T-cell subtypes.
Asunto(s)
Glucosa/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenasa/antagonistas & inhibidores , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Adulto , Ciclo del Ácido Cítrico/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Transportador de Glucosa de Tipo 1/genética , Transportador de Glucosa de Tipo 1/metabolismo , Glucólisis , Humanos , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/metabolismo , Prueba de Cultivo Mixto de Linfocitos , Masculino , Diana Mecanicista del Complejo 1 de la Rapamicina , Complejos Multiproteicos/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Subgrupos de Linfocitos T/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Triptófano/análogos & derivados , Triptófano/metabolismo , Triptófano/farmacologíaRESUMEN
PURPOSE: Acquired immunity is impaired in hemodialysis (HD) patients, and decreased T cell number may contribute. Receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) are expressed in cells of the immune system and affect T cell development, homeostasis and proliferation. Serum levels of RANKL and OPG and their relation to blood T cell number were evaluated in HD patients. METHODS: Thirty-four HD patients and 20 healthy controls participated in the study. Serum RANKL and OPG were measured by ELISA and T cell number was assessed by flow cytometry. RESULTS: Median RANKL concentration did not differ between HD patients and healthy volunteers (300.00 pmol/L; range, 3,340.00 vs. 330.00 pmol/L; range, 440.00 pmol/L; p = 0.528). Median OPG was markedly higher in HD patients than in healthy volunteers (13.12 ± 4.71 vs. 4.71 ± 0.93 pmol/L, p < 0.001). The T cell count was significantly lower in HD patients than in healthy controls (1,177.00 ± 567.71 vs. 1,519.80 ± 594.96 cells/mm(3), p = 0.044). In HD patients, blood T cell number was correlated positively with serum RANKL (ρ = 0.462, p = 0.007) and negatively to serum OPG (r = -0.449, p = 0.008). CONCLUSION: Serum OPG concentration is markedly increased in HD patients and may contribute to decreased blood T cell count and impaired acquired immunity that characterizes this population.
Asunto(s)
Osteoprotegerina/sangre , Ligando RANK/sangre , Diálisis Renal , Linfocitos T , Anciano , Proteína C-Reactiva/metabolismo , Estudios de Casos y Controles , Femenino , Humanos , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Hormona Paratiroidea/sangreRESUMEN
BACKGROUND: Acquired immunity is impaired in hemodialysis (HD) patients, and decreased T-cell number may contribute. Indoleamine 2,3-dioxygenase (IDO) and arginase type I (ARG) catabolize tryptophane and arginine, respectively, and exert proapoptotic and antiproliferative effects on T-cells. Plasma levels of IDO and ARG and their relation to blood T-cell number were evaluated in HD patients. METHODS: Thirty-two HD patients and 20 healthy controls participated in the study. Plasma IDO and ARG were measured by means of enzyme-linked immunosorbent assay. T-cell number was assessed by means of flow cytometry. RESULTS: IDO concentration was significantly higher in HD patients than in healthy volunteers (44.30 ± 31.83 ng/mL vs. 21.28 ± 26.21 ng/mL, p = 0.009). There was a trend for higher ARG concentration in HD patients (13.43 ± 11.91 ng/mL) than in healthy volunteers (9.56 ± 4.03 ng/mL), which, however, did not reach statistic significance (p = 0.099). Absolute T-cell count was significantly lower in HD patients than in healthy controls (1176.99 ± 567.71 cells/mm3 vs. 1519.85 ± 594.96 cells/mm3, p = 0.040). Absolute blood T-cell number was inversely related to plasma IDO (r = -0.490, p = 0.004) and to plasma ARG (r = -0.387, p = 0.029) concentrations. CONCLUSIONS: Plasma IDO and ARG may contribute to decreased blood T-cell count in HD patients.
Asunto(s)
Inmunidad Adaptativa , Arginasa/sangre , Indolamina-Pirrol 2,3,-Dioxigenasa/sangre , Fallo Renal Crónico/sangre , Diálisis Renal , Linfocitos T/patología , Apoptosis , Biomarcadores/sangre , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Estudios de Seguimiento , Humanos , Fallo Renal Crónico/inmunología , Fallo Renal Crónico/terapia , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , PronósticoRESUMEN
AIM: Clinical and experimental data indicate a deficient immune response in haemodialysis (HD) patients. Natural killer-like (NKL) T cells express on their surface both the T-cell antigen receptor (TCR) and a diverse set of NK-cell receptors (NKR) and share properties of both T cells and NK cells. zeta-Chain phosphorylation is an early event that follows TCR activation or some NKR activation. The zeta-chain of both T cell and NK cells is downregulated in many chronic inflammatory states, HD included. In the present study, NKL T-cell percentage and zeta-chain expression in HD patients were evaluated. METHODS: Thirty-three stable HD patients and 30 healthy volunteers were enrolled into the study. NKL T-cell percentage and NKL T-cell zeta-chain mean fluorescence intensity (MFI) were evaluated with flow cytometry. The inflammatory markers C-reactive protein, interleukin-6 and tumour necrosis factor-alpha were measured in the serum by means of enzyme-linked immunosorbent assay. RESULTS: All the evaluated markers of inflammation were increased in HD patients. In these patients, NKL T-cell percentage (1.71 +/- 1.69% vs 3.94 +/- 3.86%) and zeta-chain MFI (3.66 +/- 2.79 vs 7.03 +/- 7.91) were decreased. CONCLUSIONS: NKL T-cell percentage and zeta-chain expression is decreased in HD patients. Taking into consideration the continuously increasing age of the HD patients and that normally NKL T-cell numbers increase with age counteracting the impaired T-cell and NK-cell function accompanying advancing age, the above NKL T-cell disturbances could contribute to the impaired immune response in this population. Measures towards alleviating chronic inflammation could partially restore NKL T-cell impairment.
Asunto(s)
Complejo CD3/análisis , Inflamación/etiología , Fallo Renal Crónico/inmunología , Células Asesinas Naturales/inmunología , Receptores de Antígenos de Linfocitos T/análisis , Receptores de IgG/análisis , Diálisis Renal , Adulto , Anciano , Envejecimiento/inmunología , Proteína C-Reactiva/análisis , Enfermedad Crónica , Femenino , Humanos , Interleucina-6/sangre , Masculino , Persona de Mediana EdadRESUMEN
The aim of this study was to evaluate the effects of 3 dentin bonding agents on cell survival and proliferation and on cell cycle progression of cultured cells. The experiments were performed on RPC-C2A and L929 cells. Specimens of the 3 dentin bonding agents (Clearfil Tri-S, AdheSE, and XP BOND) were placed in culture medium, and the extraction media were applied to cells as experimental material. The effect of the bonding materials on cell survival and proliferation was assessed by a modified sulforhodamine B staining assay, and the effect on DNA synthesis was assessed by bromodeoxyuridine uptake. Flow cytometry was used for cell cycle analysis. Cell viability and proliferation decreased in a dose-dependent manner after exposure of cells to the tested materials. XP BOND expressed the highest activity of all tested bonding agents (P < .05). The self-etch bonding agents tested did not produce any significant effects on cell cycle distribution. However, exposure of cells to the total-etch agent XP BOND induced a G(2)-phase arrest in both cell lines, and this effect was more evident in L929 cells than in RPC-C2A cells.
Asunto(s)
Ciclo Celular/efectos de los fármacos , Pulpa Dental/efectos de los fármacos , Recubrimientos Dentinarios/toxicidad , Fibroblastos/efectos de los fármacos , Cementos de Resina/toxicidad , Resinas Acrílicas/toxicidad , Animales , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , ADN/biosíntesis , Pulpa Dental/citología , Células L , Ensayo de Materiales , Ratones , RatasRESUMEN
BACKGROUND: Natural killer (NK) cell activity is decreased in hemodialysis (HD) patients. Zeta-chain phosphorylation is an early event that follows the triggering of some NK cell-activating receptors. NK cell zeta-chain is downregulated in patients with cancer due to chronic inflammation. HD is also a chronic inflammatory state. NK cell zeta-chain expression in HD was evaluated. PATIENTS AND METHODS: Thirty-three HD patients and 30 healthy volunteers were enrolled into the study. The CD3-CD16+ subpopulation was examined, since it corresponds to 90% of all NK cells and has the highest cytotoxicity.NK cell count and zeta-chain mean fluorescence intensity were evaluated with flow cytometry. The inflammatory markers C-reactive protein, IL-6 and tumor necrosis factor-alpha were measured with ELISA. RESULTS: The inflammatory markers were increased in HD patients. NK cell count did not differ between HD patients and healthy volunteers. NK cell zeta-chain mean fluorescence intensity was decreased in the patient group. CONCLUSIONS: Chronic inflammation could be responsible for the NK cell zeta- chain downregulation in HD patients, contributing to the decreased NK cell activity.
Asunto(s)
Inflamación/patología , Fallo Renal Crónico/patología , Células Asesinas Naturales/patología , Receptores de Antígenos de Linfocitos T/análisis , Anciano , Biomarcadores/análisis , Complejo CD3 , Estudios de Casos y Controles , Enfermedad Crónica , Regulación hacia Abajo , Femenino , Citometría de Flujo , Humanos , Recuento de Linfocitos , Masculino , Persona de Mediana Edad , Receptores de IgG , Diálisis RenalRESUMEN
BACKGROUND: Clinical and experimental data indicate a deficient immune response in hemodialysis (HD) patients. zeta-Chain phosphorylation is an early and central event in the process that follows antigen recognition by the T cell antigen receptor (TCR). T cell zeta-chain is downregulated in many chronic inflammatory states, such as cancer, autoimmune disease and chronic infection. HD is also characterized as a chronic inflammatory state. The aim of the present study was to evaluate T cell zeta-chain expression in HD patients. PATIENTS AND METHODS: Thirty-three stable HD patients and 30 healthy volunteers were enrolled into the study. T cell count, the percentage of zeta-chain-positive T cells, as well as T cell zeta-chain mean fluorescence intensity (MFI) were evaluated with flow cytometry. The inflammatory markers C-reactive protein, interleukin-6 and tumor necrosis factor-alpha were measured in the serum by means of ELISA. RESULTS: All the evaluated markers of inflammation were increased in HD patients. In these patients, T cell zeta-chain MFI was decreased. CD3-epsilon MFI did not differ between the two groups indicating that among the TCR complex constituents, zeta-chain is selectively downregulated. CONCLUSIONS: HD is a state of chronic inflammation. Like in other pathological chronic inflammatory conditions, T cell zeta-chain is downregulated in HD patients. Since zeta-chain plays a key role in the transduction of the signal that follows antigen recognition by the TCR, its downregulation could be responsible for the deficient cellular immune response observed in HD patients.