RESUMEN
CD4+CD8+ T lymphocytes account for 1-2% of circulating human T lymphocytes, but their frequency is augmented in several diseases. The phenotypic and functional properties of these T lymphocytes are still ill-defined. We performed an ex vivo characterization of CD4+CD8+ T lymphocytes from the blood of healthy individuals. We observed that CD4+CD8+ T lymphocytes exhibit several characteristics associated with memory T lymphocytes including the expression of chemokine receptors (e.g. CCR7, CXCR3, CCR6) and activation markers (e.g. CD57, CD95). Moreover, we showed that a greater proportion of CD4+CD8+ T lymphocytes have an enhanced capacity to produce cytokines (IFNγ, TNFα, IL-2, IL-4, IL-17A) and lytic enzymes (perforin, granzyme B) compared to CD4+ and/or CD8+ T lymphocytes. Finally, we assessed the impact of three key cytokines in T cell biology on these cells. We observed that IL-2, IL-7 and IL-15 triggered STAT5 phosphorylation in a greater proportion of CD4+CD8+ T lymphocytes compared to CD4 and CD8 counterparts. We demonstrate that CD4+CD8+ T lymphocytes from healthy donors exhibit a phenotypic profile associated with memory T lymphocytes, an increased capacity to produce cytokines and lytic enzymes, and a higher proportion of cells responding to key cytokines implicated in T cell survival, homeostasis and activation.
Asunto(s)
Citocinas/metabolismo , Memoria Inmunológica , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Biomarcadores , Antígenos CD4/metabolismo , Antígenos CD8/metabolismo , Células Cultivadas , Citocinas/farmacología , Citotoxicidad Inmunológica , Humanos , Inmunofenotipificación , Interleucina-15/metabolismo , Interleucina-15/farmacología , Interleucina-2/metabolismo , Interleucina-2/farmacología , Interleucina-7/metabolismo , Interleucina-7/farmacología , Fenotipo , Subgrupos de Linfocitos T/efectos de los fármacosRESUMEN
Immune cells have been implicated in the pathogenesis of hypertension. We hypothesized that under the influence of chromosome (chr)2, T lymphocytes contribute to vascular inflammation in genetic salt-sensitive hypertension. Normotensive (Brown Norway), hypertensive (Dahl salt-sensitive), and consomic rats (SSBN2; in which chr2 has been transferred from Brown Norway to Dahl rats) were studied. Systolic blood pressure, measured by tail cuff, and aortic preproendothelin mRNA, measured by quantitative RT-PCR, were elevated in Dahl rats compared with Brown Norway rats and were reduced in SSBN2 rats compared with Dahl rats (P < 0.01). Compared with Brown Norway rats, Dahl rats exhibited increased inflammatory markers and mediators such as nuclear translocation of the aortic p65 subunit of NF-kappaB as well as VCAM-1, ICAM-1, chemokine (C-C motif) receptor 5, and CD4 mRNA, all of which were reduced in SSBN2 rats. Aortic CD8 mRNA was equally increased in Dahl and SSBN2 rats relative to Brown Norway rats. CD4(+) T cell infiltration in the aorta of SSBN2 rats was reduced compared with Dahl rats, whereas the aortic protein expression of Foxp3b and immunosuppressors transforming growth factor (TGF)-beta(1) and IL-10, the three markers associated with the regulatory T cell lineage, were enhanced in SSBN2 rats. Activation in vitro of T cells demonstrated that CD4(+)CD25(+) and CD8(+)CD25(+) cells (Tregs) produce IL-10 in SSBN2 rats. Thus, increased vascular inflammatory responses and hypertension in a genetic salt-sensitive hypertensive rodent model are reduced by transfer of chr2 from a normotensive strain, and this is associated with enhanced levels of immunosuppressive mediators.
Asunto(s)
Inmunidad Adaptativa/fisiología , Presión Sanguínea/fisiología , Hipertensión/genética , Hipertensión/fisiopatología , Vasculitis/fisiopatología , Animales , Aorta/metabolismo , Aorta/patología , Aorta/fisiopatología , Recuento de Células , Modelos Animales de Enfermedad , Factores de Transcripción Forkhead/metabolismo , Predisposición Genética a la Enfermedad , Interleucina-10/metabolismo , Masculino , Ratas , Ratas Endogámicas BN , Ratas Endogámicas Dahl , Ratas Endogámicas , Linfocitos T Reguladores/patología , Factor de Crecimiento Transformador beta1/metabolismo , Vasculitis/metabolismo , Vasculitis/patologíaRESUMEN
Vascular superoxide anion (O(2)(*-)) levels are increased in DOCA-salt hypertensive rats. We hypothesized that the endothelin (ET)-1-induced generation of ROS in the aorta and resistance arteries of DOCA-salt rats originates partly from xanthine oxidase (XO) and mitochondria. Accordingly, we blocked XO and the mitochondrial oxidative phosphorylation chain to investigate their contribution to ROS production in mesenteric resistance arteries and the aorta from DOCA-salt rats. Systolic blood pressure rose in DOCA-salt rats and was reduced after 3 wk by apocynin [NAD(P)H oxidase inhibitor and/or radical scavenger], allopurinol (XO inhibitor), bosentan (ET(A/B) receptor antagonist), BMS-182874 (BMS; ET(A) receptor antagonist), and hydralazine. Plasma uric acid levels in DOCA-salt rats were similar to control unilaterally nephrectomized (UniNx) rats, reduced with allopurinol and bosentan, and increased with BMS. Levels of thiobarbituric acid-reacting substances were increased in DOCA-salt rats versus UniNx rats, and BMS, bosentan, and hydralazine prevented their increase. Dihydroethidium staining showed reduced O(2)(*-) production in mesenteric arteries and the aorta from BMS- and bosentan-treated DOCA-salt rats compared with untreated DOCA-salt rats. Increased O(2)(*-) derived from XO was reduced or prevented by all treatments in mesenteric arteries, whereas bosentan and BMS had no effect on aortas from DOCA-salt rats. O(2)(*-) generation decreased with in situ treatment by tenoyltrifluoroacetone and CCCP, inhibitors of mitochondrial electron transport complexes II and IV, respectively, whereas rotenone (mitochondrial complex I inhibitor) had no effect. Our findings demonstrate the involvement of ET(A) receptor-modulated O(2)(*-) derived from XO and from mitochondrial oxidative enzymes in arteries from DOCA-salt rats.
Asunto(s)
Aorta/metabolismo , Hipertensión/metabolismo , Arterias Mesentéricas/metabolismo , Mitocondrias/metabolismo , Superóxidos/metabolismo , Xantina Oxidasa/metabolismo , Animales , Antihipertensivos/farmacología , Aorta/efectos de los fármacos , Aorta/enzimología , Aorta/fisiopatología , Presión Sanguínea , Creatinina/sangre , Desoxicorticosterona , Modelos Animales de Enfermedad , Antagonistas de los Receptores de Endotelina , Endotelina-1/metabolismo , Inhibidores Enzimáticos/farmacología , Depuradores de Radicales Libres/farmacología , Hipertensión/inducido químicamente , Hipertensión/enzimología , Hipertensión/fisiopatología , Peroxidación de Lípido , Masculino , Arterias Mesentéricas/efectos de los fármacos , Arterias Mesentéricas/enzimología , Arterias Mesentéricas/fisiopatología , Mitocondrias/efectos de los fármacos , Mitocondrias/enzimología , NADPH Oxidasas/antagonistas & inhibidores , NADPH Oxidasas/metabolismo , Nefrectomía , Fosforilación Oxidativa , Ratas , Ratas Sprague-Dawley , Receptores de Endotelina/metabolismo , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Desacopladores/farmacología , Ácido Úrico/sangre , Resistencia Vascular , Xantina Oxidasa/antagonistas & inhibidoresRESUMEN
Angiotensin (Ang) II is implicated in hypertension, vascular remodeling, and insulin resistance. Peroxisome proliferator-activated receptor (PPAR) gamma activators increase insulin sensitivity and improve Ang II-induced vascular remodeling. We evaluated the effects of the PPAR-gamma activator rosiglitazone on Ang II signaling in aorta and mesenteric arteries. Rats received Ang II by subcutaneous infusion and/or rosiglitazone per os for 7 days. Blood pressure rise in Ang II-infused rats was attenuated by rosiglitazone. Ang II significantly increased Ang II type 1 receptor expression in the mesenteric arteries (P<0.001), whereas that of the aorta was decreased (P<0.05), changes which were reversed by rosiglitazone. Akt activity was increased by Ang II and returned to basal levels under rosiglitazone in both vascular beds. However, Ang II-induced extracellular signal-regulated kinase 1/2 activity increased in aorta but not in mesenteric vessels (P<0.001), where 4E-binding protein 1 activity was significantly increased by Ang II and inhibited by PPAR-gamma activation. In response to Ang II, Src homology (SH) 2-containing inositol phosphatase 2 activity was increased (P<0.05) in both vascular beds. In conclusion, PPAR-gamma activator rosiglitazone attenuated Ang II-induced blood pressure elevation and intracellular signaling on aorta and mesenteric vessels. There was differential inhibition of Ang II type 1 receptor receptors/phosphatidylinositol 3-kinase/Akt and extracellular signal-regulated kinase 1/2 in both vessels. Effects of PPAR-gamma activators on these pathways could contribute to regression of vascular remodeling in models of hypertension and diabetes and, accordingly, in hypertensive diabetic patients.
Asunto(s)
Angiotensina II/farmacología , Aorta/enzimología , Arterias Mesentéricas/enzimología , Proteínas Quinasas Activadas por Mitógenos/metabolismo , PPAR gamma/fisiología , Fosfatidilinositol 3-Quinasas/metabolismo , Vasoconstrictores/farmacología , Animales , Aorta/metabolismo , Presión Sanguínea/efectos de los fármacos , Masculino , Arterias Mesentéricas/metabolismo , PPAR gamma/metabolismo , Ratas , Ratas Sprague-Dawley , Receptor de Angiotensina Tipo 1/metabolismo , Rosiglitazona , Transducción de Señal/efectos de los fármacos , Tiazolidinedionas/farmacología , Vasodilatadores/farmacologíaRESUMEN
BACKGROUND: The aim of this study was to investigate the involvement of angiotensin II and oxidative stress on cardiovascular damage induced by chronic subcutaneous aldosterone infusion in the absence of salt loading. METHODS: Sprague-Dawley rats were infused with d-aldosterone (0.75 microg/h subcutaneously) for 6 weeks. Blood pressure was measured with the tail-cuff method. Small arteries were investigated on a pressurized myograph. Cardiovascular and renal collagen was evaluated by Sirius red staining. Systemic oxidant excess was measured with plasma 8-isoprostane by ELISA and by measurement of thiobarbituric acid-reactive substances. Vascular reactive oxygen species were studied using hydroethidine and NADPH-generated superoxide anion measured by lucigenin chemiluminescence. RESULTS: After 6 weeks of treatment, systolic blood pressure was significantly increased in aldosterone-infused rats (170+/-8 v 123+/-2 mm Hg in controls, P < .05). Progression of hypertension was partially prevented by co-administration of losartan (AT1 receptor blocker) or tempol (superoxide dismutase mimetic): 140+/-4 and 149+/-6 mm Hg, respectively, P < .05 versus the aldosterone group. Aldosterone induced renal but not cardiac hypertrophy, which was not prevented by losartan or by tempol. Moreover, losartan and tempol failed to prevent vascular hypertrophy of resistance mesenteric vessels. However, losartan (0.77%+/-0.05%) and tempol (0.65%+/-0.10%) prevented cardiac fibrosis in the midmyocardium in the aldosterone group (1.03%+/-0.12% v 0.68%+/-0.07% positive staining per area in control, P < .05). In the kidney, collagen accumulation of aldosterone-infused rats was also significantly decreased by losartan (-77%) and tempol (-60%). Similar effects were obtained on aortic fibrosis. Aldosterone increased serum 8-isoprostane levels.This increase was blunted by losartan and tempol. Losartan and tempol totally prevented vascular, cardiac, and renal increase of NADPH-induced superoxide production stimulated by aldosterone. CONCLUSIONS: Our data suggest that the profibrotic but not the hypertrophic action of aldosterone are mediated at least in part by reactive oxygen species generation and involve an interaction with the renin-angiotensin system.
Asunto(s)
Aldosterona/administración & dosificación , Estrés Oxidativo/efectos de los fármacos , Sistema Renina-Angiotensina/efectos de los fármacos , Animales , Antihipertensivos/administración & dosificación , Antioxidantes/administración & dosificación , Biomarcadores/sangre , Presión Sanguínea/efectos de los fármacos , Óxidos N-Cíclicos/administración & dosificación , Modelos Animales de Enfermedad , Endocardio/efectos de los fármacos , Endocardio/patología , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/metabolismo , Endotelio Vascular/fisiopatología , Fibrosis , Infusiones Intraarteriales , Riñón/efectos de los fármacos , Riñón/patología , Losartán/administración & dosificación , Masculino , Modelos Cardiovasculares , NADP/efectos de los fármacos , NADP/metabolismo , Nitroprusiato/administración & dosificación , Pericardio/efectos de los fármacos , Pericardio/patología , Ratas , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismo , Marcadores de Spin , Sístole/efectos de los fármacos , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Vasodilatadores/administración & dosificaciónRESUMEN
Peroxisome proliferator-activated receptor (PPAR) activation may prevent cardiac hypertrophy and inhibit production of endothelin-1 (ET-1), a hypertrophic agent. The aim of this in vivo study was to investigate the effects of PPAR activators on cardiac remodeling in DOCA-salt rats, a model overexpressing ET-1. Unilaterally nephrectomized 16-week-old Sprague-Dawley rats (Uni-Nx) were randomly divided into 4 groups: control rats, DOCA-salt, DOCA-salt+rosiglitazone (PPAR-gamma activator, 5 mg/kg per day), and DOCA-salt+fenofibrate (PPAR-alpha activator, 100 mg/kg per day). After 3 weeks of treatment, mean arterial blood pressure was significantly increased in DOCA-salt by 36 mm Hg. Mean arterial blood pressure was normalized by coadministration of rosiglitazone but not by fenofibrate. Both PPAR activators prevented cardiac fibrosis and abrogated the increase in prepro-ET-1 mRNA content in the left ventricle of DOCA-salt rats. Coadministration of rosiglitazone or fenofibrate failed to prevent thickening of left ventricle (LV) walls as measured by echocardiography and the increase in atrial natriuretic peptide mRNA levels. However, rosiglitazone and fenofibrate prevented the decrease in LV internal diameter and thus concentric remodeling of the LV found in DOCA-salt rats. Taken together, these data indicate a modulatory role of PPAR activators on cardiac remodeling in mineralocorticoid-induced hypertension, in part associated with decreased ET-1 production.