Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 53
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Immunity ; 52(5): 782-793.e5, 2020 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-32272082

RESUMEN

Splenic red pulp macrophages (RPMs) contribute to erythrocyte homeostasis and are required for iron recycling. Heme induces the expression of SPIC transcription factor in monocyte-derived macrophages and promotes their differentiation into RPM precursors, pre-RPMs. However, the requirements for differentiation into mature RPMs remain unknown. Here, we have demonstrated that interleukin (IL)-33 associated with erythrocytes and co-cooperated with heme to promote the generation of mature RPMs through activation of the MyD88 adaptor protein and ERK1/2 kinases downstream of the IL-33 receptor, IL1RL1. IL-33- and IL1RL1-deficient mice showed defective iron recycling and increased splenic iron deposition. Gene expression and chromatin accessibility studies revealed a role for GATA transcription factors downstream of IL-33 signaling during the development of pre-RPMs that retained full potential to differentiate into RPMs. Thus, IL-33 instructs the development of RPMs as a response to physiological erythrocyte damage with important implications to iron recycling and iron homeostasis.


Asunto(s)
Proteína 1 Similar al Receptor de Interleucina-1/inmunología , Interleucina-33/inmunología , Hierro/metabolismo , Macrófagos/inmunología , Transducción de Señal/inmunología , Bazo/metabolismo , Animales , Eritrocitos/inmunología , Eritrocitos/metabolismo , Hemo/inmunología , Hemo/metabolismo , Homeostasis/inmunología , Proteína 1 Similar al Receptor de Interleucina-1/genética , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Interleucina-33/genética , Interleucina-33/metabolismo , Macrófagos/metabolismo , Ratones Noqueados , Proteína Quinasa 1 Activada por Mitógenos/inmunología , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/inmunología , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Factor 88 de Diferenciación Mieloide/inmunología , Factor 88 de Diferenciación Mieloide/metabolismo , Bazo/citología
2.
Nature ; 594(7864): 560-565, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-34040253

RESUMEN

Myocardial infarction is a major cause of premature death in adults. Compromised cardiac function after myocardial infarction leads to chronic heart failure with systemic health complications and a high mortality rate1. Effective therapeutic strategies are needed to improve the recovery of cardiac function after myocardial infarction. More specifically, there is a major unmet need for a new class of drugs that can improve cardiomyocyte contractility, because inotropic therapies that are currently available have been associated with high morbidity and mortality in patients with systolic heart failure2,3 or have shown a very modest reduction of risk of heart failure4. Microtubule detyrosination is emerging as an important mechanism for the regulation of cardiomyocyte contractility5. Here we show that deficiency of microtubule-affinity regulating kinase 4 (MARK4) substantially limits the reduction in the left ventricular ejection fraction after acute myocardial infarction in mice, without affecting infarct size or cardiac remodelling. Mechanistically, we provide evidence that MARK4 regulates cardiomyocyte contractility by promoting phosphorylation of microtubule-associated protein 4 (MAP4), which facilitates the access of vasohibin 2 (VASH2)-a tubulin carboxypeptidase-to microtubules for the detyrosination of α-tubulin. Our results show how the detyrosination of microtubules in cardiomyocytes is finely tuned by MARK4 to regulate cardiac inotropy, and identify MARK4 as a promising therapeutic target for improving cardiac function after myocardial infarction.


Asunto(s)
Insuficiencia Cardíaca/fisiopatología , Microtúbulos/química , Infarto del Miocardio/fisiopatología , Proteínas Serina-Treonina Quinasas/fisiología , Tirosina/química , Proteínas Angiogénicas , Animales , Carboxipeptidasas , Células Cultivadas , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Asociadas a Microtúbulos , Miocitos Cardíacos , Volumen Sistólico , Función Ventricular Izquierda
3.
Nature ; 597(7874): 92-96, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34433968

RESUMEN

Atherosclerotic cardiovascular disease causes heart attacks and strokes, which are the leading causes of mortality worldwide1. The formation of atherosclerotic plaques is initiated when low-density lipoproteins bind to heparan-sulfate proteoglycans (HSPGs)2 and become trapped in the subendothelial space of large and medium size arteries, which leads to chronic inflammation and remodelling of the artery wall2. A proliferation-inducing ligand (APRIL) is a cytokine that binds to HSPGs3, but the physiology of this interaction is largely unknown. Here we show that genetic ablation or antibody-mediated depletion of APRIL aggravates atherosclerosis in mice. Mechanistically, we demonstrate that APRIL confers atheroprotection by binding to heparan sulfate chains of heparan-sulfate proteoglycan 2 (HSPG2), which limits the retention of low-density lipoproteins, accumulation of macrophages and formation of necrotic cores. Indeed, antibody-mediated depletion of APRIL in mice expressing heparan sulfate-deficient HSPG2 had no effect on the development of atherosclerosis. Treatment with a specific anti-APRIL antibody that promotes the binding of APRIL to HSPGs reduced experimental atherosclerosis. Furthermore, the serum levels of a form of human APRIL protein that binds to HSPGs, which we termed non-canonical APRIL (nc-APRIL), are associated independently of traditional risk factors with long-term cardiovascular mortality in patients with atherosclerosis. Our data reveal properties of APRIL that have broad pathophysiological implications for vascular homeostasis.


Asunto(s)
Aterosclerosis/metabolismo , Aterosclerosis/prevención & control , Proteoglicanos de Heparán Sulfato/metabolismo , Miembro 13 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/metabolismo , Animales , Antígeno de Maduración de Linfocitos B/metabolismo , Sitios de Unión , Enfermedades Cardiovasculares/sangre , Enfermedades Cardiovasculares/mortalidad , Femenino , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Unión Proteica , Proteína Activadora Transmembrana y Interactiva del CAML/metabolismo , Miembro 13 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/sangre , Miembro 13 de la Superfamilia de Ligandos de Factores de Necrosis Tumoral/deficiencia
4.
J Am Soc Nephrol ; 34(7): 1207-1221, 2023 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-37022108

RESUMEN

SIGNIFICANCE STATEMENT: Kidney-derived thrombopoietin (TPO) increases myeloid cell and platelet production during antibody-mediated chronic kidney disease (AMCKD) in a mouse model, exacerbating chronic thromobinflammation in microvessels. The effect is mirrored in patients with extracapillary glomerulonephritis associated with thromboinflammation, TGF ß -dependent glomerulosclerosis, and increased bioavailability of TPO. Neutralization of TPO in mice normalized hematopoiesis, reduced chronic thromboinflammation, and ameliorated renal disease. The findings suggest that TPO is a relevant biomarker and a promising therapeutic target for patients with CKD and other chronic thromboinflammatory diseases.Neutralization of TPO in mice normalized hematopoiesis, reduced chronic thromboinflammation, and ameliorated renal disease. The findings suggest that TPO is a relevant biomarker and a promising therapeutic target for patients with CKD and other chronic thromboinflammatory diseases. BACKGROUND: Chronic thromboinflammation provokes microvascular alterations and rarefaction, promoting organ dysfunction in individuals with various life-threatening diseases. Hematopoietic growth factors (HGFs) released by the affected organ may sustain emergency hematopoiesis and fuel the thromboinflammatory process. METHODS: Using a murine model of antibody-mediated chronic kidney disease (AMCKD) and pharmacological interventions, we comprehensively monitored the response to injury in the circulating blood, urine, bone marrow, and kidney. RESULTS: Experimental AMCKD was associated with chronic thromboinflammation and the production of HGFs, especially thrombopoietin (TPO), by the injured kidney, which stimulated and skewed hematopoiesis toward myelo-megakaryopoiesis. AMCKD was characterized by vascular and kidney dysfunction, TGF ß -dependent glomerulosclerosis, and microvascular rarefaction. In humans, extracapillary glomerulonephritis is associated with thromboinflammation, TGF ß -dependent glomerulosclerosis, and increased bioavailability of TPO. Analysis of albumin, HGF, and inflammatory cytokine levels in sera from patients with extracapillary glomerulonephritis allowed us to identify treatment responders. Strikingly, TPO neutralization in the experimental AMCKD model normalized hematopoiesis, reduced chronic thromboinflammation, and ameliorated renal disease. CONCLUSION: TPO-skewed hematopoiesis exacerbates chronic thromboinflammation in microvessels and worsens AMCKD. TPO is both a relevant biomarker and a promising therapeutic target in humans with CKD and other chronic thromboinflammatory diseases.


Asunto(s)
Glomerulonefritis , Insuficiencia Renal Crónica , Trombosis , Humanos , Ratones , Animales , Trombopoyetina/metabolismo , Trombopoyetina/farmacología , Receptores de Trombopoyetina , Inflamación , Tromboinflamación , Hematopoyesis/fisiología , Anticuerpos/farmacología , Riñón/metabolismo , Insuficiencia Renal Crónica/etiología , Factor de Crecimiento Transformador beta/farmacología
5.
J Neurochem ; 157(3): 561-573, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33382098

RESUMEN

Hepatic encephalopathy (HE) is a debilitating neurological complication of cirrhosis. By definition, HE is considered a reversible disorder, and therefore HE should resolve following liver transplantation (LT). However, persisting neurological complications are observed in as many as 47% of LT recipients. LT is an invasive surgical procedure accompanied by various perioperative factors such as blood loss and hypotension which could influence outcomes post-LT. We hypothesize that minimal HE (MHE) renders the brain frail and susceptible to hypotension-induced neuronal cell death. Six-week bile duct-ligated (BDL) rats with MHE and respective SHAM-controls were used. Several degrees of hypotension (mean arterial pressure of 30, 60 and 90 mm Hg) were induced via blood withdrawal from the femoral artery and maintained for 120 min. Brains were collected for neuronal cell count and apoptotic analysis. In a separate group, BDL rats were treated for MHE with the ammonia-lowering strategy ornithine phenylacetate (OP; MNK-6105), administered orally (1 g/kg) for 3 weeks before induction of hypotension. Hypotension 30 and 60 mm Hg (not 90 mm Hg) significantly decreased neuronal marker expression (NeuN) and cresyl violet staining in the frontal cortex compared to respective hypotensive SHAM-operated controls as well as non-hypotensive BDL rats. Neuronal degeneration was associated with an increase in cleaved caspase-3, suggesting the mechanism of cell death was apoptotic. OP treatment attenuated hyperammonaemia, improved anxiety and activity, and protected the brain against hypotension-induced neuronal cell death. Our findings demonstrate that rats with chronic liver disease and MHE are more susceptible to hypotension-induced neuronal cell degeneration. This highlights MHE at the time of LT is a risk factor for poor neurological outcome post-transplant and that treating for MHE pre-LT might reduce this risk.


Asunto(s)
Amoníaco/metabolismo , Conductos Biliares , Hipotensión/patología , Enfermedades Neurodegenerativas/patología , Neuronas/patología , Amoníaco/sangre , Animales , Antígenos Nucleares/metabolismo , Ansiedad/psicología , Apoptosis , Conducta Animal , Caspasa 3/metabolismo , Circulación Cerebrovascular/efectos de los fármacos , Modelos Animales de Enfermedad , Encefalopatía Hepática/patología , Hiperamonemia , Ligadura , Masculino , Proteínas del Tejido Nervioso/metabolismo , Enfermedades Neurodegenerativas/metabolismo , Enfermedades Neurodegenerativas/psicología , Ornitina/análogos & derivados , Ornitina/uso terapéutico , Ratas , Ratas Sprague-Dawley
6.
Circ Res ; 125(11): 1019-1034, 2019 11 08.
Artículo en Inglés | MEDLINE | ID: mdl-31610723

RESUMEN

RATIONALE: Atherosclerosis is a chronic inflammatory disease. Recent studies have shown that dysfunctional autophagy in endothelial cells, smooth muscle cells, and macrophages, plays a detrimental role during atherogenesis, leading to the suggestion that autophagy-stimulating approaches may provide benefit. OBJECTIVE: Dendritic cells (DCs) are at the crossroad of innate and adaptive immune responses and profoundly modulate the development of atherosclerosis. Intriguingly, the role of autophagy in DC function during atherosclerosis and how the autophagy process would impact disease development has not been addressed. METHODS AND RESULTS: Here, we show that the autophagic flux in atherosclerosis-susceptible Ldlr-/- (low-density lipoprotein receptor-deficient) mice is substantially higher in splenic and aortic DCs compared with macrophages and is further activated under hypercholesterolemic conditions. RNA sequencing and functional studies on selective cell populations reveal that disruption of autophagy through deletion of Atg16l1 differentially affects the biology and functions of DC subsets in Ldlr-/- mice under high-fat diet. Atg16l1 deficient CD11b+ DCs develop a TGF (transforming growth factor)-ß-dependent tolerogenic phenotype and promote the expansion of regulatory T cells, whereas no such effects are seen with Atg16l1 deficient CD8α+ DCs. Atg16l1 deletion in DCs (all CD11c-expressing cells) expands aortic regulatory T cells in vivo, limits the accumulation of T helper cells type 1, and reduces the development of atherosclerosis in Ldlr-/- mice. In contrast, no such effects are seen when Atg16l1 is deleted selectively in conventional CD8α+ DCs and CD103+ DCs. Total T-cell or selective regulatory T-cell depletion abrogates the atheroprotective effect of Atg16l1 deficient DCs. CONCLUSIONS: In contrast to its proatherogenic role in macrophages, autophagy disruption in DCs induces a counter-regulatory response that maintains immune homeostasis in Ldlr-/- mice under high-fat diet and limits atherogenesis. Selective modulation of autophagy in DCs could constitute an interesting therapeutic target in atherosclerosis.


Asunto(s)
Aorta/inmunología , Enfermedades de la Aorta/prevención & control , Aterosclerosis/prevención & control , Autofagia , Antígeno CD11b/inmunología , Comunicación Celular , Proliferación Celular , Células Dendríticas/inmunología , Activación de Linfocitos , Linfocitos T Reguladores/inmunología , Animales , Aorta/metabolismo , Aorta/patología , Enfermedades de la Aorta/inmunología , Enfermedades de la Aorta/metabolismo , Enfermedades de la Aorta/patología , Aterosclerosis/inmunología , Aterosclerosis/metabolismo , Aterosclerosis/patología , Proteína 5 Relacionada con la Autofagia/metabolismo , Proteínas Relacionadas con la Autofagia/genética , Proteínas Relacionadas con la Autofagia/metabolismo , Trasplante de Médula Ósea , Antígenos CD11/genética , Antígenos CD11/metabolismo , Antígeno CD11b/metabolismo , Células Cultivadas , Células Dendríticas/metabolismo , Modelos Animales de Enfermedad , Femenino , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Placa Aterosclerótica , Receptores Inmunológicos/genética , Receptores Inmunológicos/metabolismo , Receptores de LDL/genética , Receptores de LDL/metabolismo , Transducción de Señal , Linfocitos T Reguladores/metabolismo
7.
Circ Res ; 122(6): 813-820, 2018 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-29436389

RESUMEN

RATIONALE: Despite an established role for adaptive immune responses in atherosclerosis, the contribution of dendritic cells (DCs) and their various subsets is still poorly understood. OBJECTIVE: Here, we address the role of IRF8 (interferon regulatory factor 8)-dependent DCs (lymphoid CD8α+ and their developmentally related nonlymphoid CD103+ DCs) in the induction of proatherogenic immune responses during high fat feeding. METHODS AND RESULTS: Using a fate-mapping technique to track DCs originating from a DNGR1+ (dendritic cell natural killer lectin group receptor 1) precursor (Clec9a+/creRosa+/EYFP mice), we first show that YFPhiCD11chiMHCIIhi (major histocompatibility complex class II) DCs are present in the atherosclerotic aorta of low-density lipoprotein receptor-deficient (Ldlr-/-) mice and are CD11b-CD103+IRF8hi. Restricted deletion of IRF8 in DCs (Irf8flox/floxCd11cCre ) reduces the accumulation of CD11chiMHCIIhi DCs in the aorta without affecting CD11b+CD103- DCs or macrophages but completely abolishes the accumulation of aortic CD11b-CD103+ DCs. Lymphoid CD8α+ DCs are also deleted. This is associated with a significant reduction of aortic T-cell accumulation and a marked reduction of high-fat diet-induced systemic T-cell priming, activation, and differentiation toward T helper type 1 cells, T follicular helper cells, and regulatory T cells. As a consequence, B-cell activation and germinal center responses to high-fat diet are also markedly reduced. IRF8 deletion in DCs significantly reduces the development of atherosclerosis, predominantly in the aortic sinus, despite a modest increase in total plasma cholesterol levels. CONCLUSIONS: IRF8 expression in DCs plays a nonredundant role in the development of proatherogenic adaptive immunity.


Asunto(s)
Inmunidad Adaptativa , Aterosclerosis/inmunología , Células Dendríticas/inmunología , Factores Reguladores del Interferón/metabolismo , Animales , Aorta/citología , Aterosclerosis/etiología , Antígenos CD11/genética , Antígenos CD11/metabolismo , Células Cultivadas , Dieta Alta en Grasa/efectos adversos , Femenino , Antígenos de Histocompatibilidad Clase II/genética , Antígenos de Histocompatibilidad Clase II/metabolismo , Factores Reguladores del Interferón/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Linfocitos T/inmunología
8.
Arterioscler Thromb Vasc Biol ; 39(6): 1149-1159, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30943775

RESUMEN

Objective- Recent studies suggested the occurrence of phenotypic switching of vascular smooth muscle cells (VSMCs) during the development of aortic aneurysm (AA). However, lineage-tracing studies are still lacking, and the behavior of VSMCs during the formation of dissecting AA is poorly understood. Approach and Results- We used multicolor lineage tracing of VSMCs to track their fate after injury in murine models of Ang II (angiotensin II)-induced dissecting AA. We also addressed the direct impact of autophagy on the response of VSMCs to AA dissection. Finally, we studied the relevance of these processes to human AAs. Here, we show that a subset of medial VSMCs undergoes clonal expansion and that VSMC outgrowths are observed in the adventitia and borders of the false channel during Ang II-induced development of dissecting AA. The clonally expanded VSMCs undergo phenotypic switching with downregulation of VSMC differentiation markers and upregulation of phagocytic markers, indicative of functional changes. In particular, autophagy and endoplasmic reticulum stress responses are activated in the injured VSMCs. Loss of autophagy in VSMCs through deletion of autophagy protein 5 gene ( Atg5) increases the susceptibility of VSMCs to death, enhances endoplasmic reticulum stress activation, and promotes IRE (inositol-requiring enzyme) 1α-dependent VSMC inflammation. These alterations culminate in increased severity of aortic disease and higher incidence of fatal AA dissection in mice with VSMC-restricted deletion of Atg5. We also report increased expression of autophagy and endoplasmic reticulum stress markers in VSMCs of human dissecting AAs. Conclusions- VSMCs undergo clonal expansion and phenotypic switching in Ang II-induced dissecting AAs in mice. We also identify a critical role for autophagy in regulating VSMC death and endoplasmic reticulum stress-dependent inflammation with important consequences for aortic wall homeostasis and repair.


Asunto(s)
Aneurisma de la Aorta/patología , Disección Aórtica/patología , Autofagia , Plasticidad de la Célula , Músculo Liso Vascular/patología , Miocitos del Músculo Liso/patología , Adulto , Anciano , Disección Aórtica/inducido químicamente , Disección Aórtica/metabolismo , Angiotensina II , Animales , Aorta/metabolismo , Aorta/patología , Aneurisma de la Aorta/inducido químicamente , Aneurisma de la Aorta/metabolismo , Proteína 5 Relacionada con la Autofagia/genética , Proteína 5 Relacionada con la Autofagia/metabolismo , Linaje de la Célula , Células Cultivadas , Modelos Animales de Enfermedad , Endorribonucleasas/metabolismo , Femenino , Humanos , Masculino , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Ratones Noqueados para ApoE , Persona de Mediana Edad , Músculo Liso Vascular/metabolismo , Miocitos del Músculo Liso/metabolismo , Fenotipo , Proteínas Serina-Treonina Quinasas/metabolismo , Transducción de Señal
9.
Arterioscler Thromb Vasc Biol ; 39(8): 1645-1651, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31167564

RESUMEN

OBJECTIVE: MARK4 (microtubule affinity-regulating kinase 4) regulates NLRP3 (nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 3) inflammasome activation. The aim of the study is to examine the role of MARK4 in hematopoietic cells during atherosclerosis. METHODS AND RESULTS: We show increased MARK4 expression in human atherosclerotic lesions compared with adjacent areas. MARK4 is coexpressed with NLRP3, and they colocalize in areas enriched in CD68-positive but α-SMA (α-smooth muscle actin)-negative cells. Expression of MARK4 and NLRP3 in the atherosclerotic lesions is associated with the production of active IL (interleukin)-1ß and IL-18. To directly assess the role of hematopoietic MARK4 in NLRP3 inflammasome activation and atherosclerotic plaque formation, Ldlr (low-density lipoprotein receptor)-deficient mice were lethally irradiated and reconstituted with either wild-type or Mark4-deficient bone marrow cells, and were subsequently fed a high-fat diet and cholesterol diet for 9 weeks. Mark4 deficiency in bone marrow cells led to a significant reduction of lesion size, together with decreased circulating levels of IL-18 and IFN-γ (interferon-γ). Furthermore, Mark4 deficiency in primary murine bone marrow-derived macrophages prevented cholesterol crystal-induced NLRP3 inflammasome activation, as revealed by reduced caspase-1 activity together with reduced production of IL-1ß and IL-18. CONCLUSIONS: MARK4-dependent NLRP3 inflammasome activation in the hematopoietic cells regulates the development of atherosclerosis.


Asunto(s)
Aterosclerosis/etiología , Inflamasomas/fisiología , Proteína con Dominio Pirina 3 de la Familia NLR/fisiología , Proteínas Serina-Treonina Quinasas/fisiología , Anciano , Anciano de 80 o más Años , Animales , Células Cultivadas , Humanos , Interleucina-18/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Receptores de LDL/fisiología
10.
J Vasc Surg ; 70(2): 588-598.e2, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30792060

RESUMEN

OBJECTIVE: Macrophages play a critical role in the initiation and progression of abdominal aortic aneurysm (AAA) and are classically distinguished into M1 "proinflammatory" and M2 "anti-inflammatory" macrophages. Topical application of elastase associated with transforming growth factor ß (TGF-ß) systemic neutralization reproduces the main pathologic features of human AAA, offering a new model to investigate their role. The aim of this study was to investigate whether macrophages contribute to the expression of canonical M1/M2 markers in the aorta in the AAA model induced by elastase and systemic blockade of TGF-ß and whether blocking of TGF-ß activity affects macrophage phenotype and the expression of the M2 marker arginase 1 (ARG1). METHODS: C57Bl/6J male mice (6-8 weeks old) were randomly assigned to three experimental groups: mice that had local application of heat-inactivated elastase or elastase and mice that had elastase application and received injection of anti-TGF-ß (elastase + anti-TGF-ß group). Monocyte-macrophage depletion was achieved in the elastase + anti-TGF-ß group using liposome clodronate. Macrophage phenotype was characterized by quantitative polymerase chain reaction, flow cytometry, and immunohistochemistry. Human infrarenal AAA tissues (n = 10) were obtained to analyze ARG1 expression. RESULTS: Analysis of gene expression in the infrarenal aortic wall revealed that after 14 days, no significant difference for the expression of CCL2, NOS2, and Ym1/2 was observed in the elastase group compared with the elastase + anti-TGF-ß group, whereas the expression of ARG1, interleukin (IL) 1ß, and IL-6 was significantly increased. Macrophage depletion in the elastase + anti-TGF-ß group led to a significant decrease of IL-1ß, IL-6, ARG1, and Ym1/2 gene expression. Immunofluorescent staining confirmed that TGF-ß neutralization significantly enhanced ARG1 protein expression in the aneurysmal tissue. Flow cytometry analysis revealed an increase of macrophages expressing ARG1 in the aorta of mice treated with elastase + anti-TGF-ß compared with the elastase group, and their proportion increased with aneurysmal dilation. In humans, ARG1 protein expression was increased in aneurysmal tissues compared with controls, and positive cells were mainly found in the adventitia. CONCLUSIONS: TGF-ß neutralization finely tunes macrophage phenotype in elastase-induced AAA and leads to an increase in ARG1 gene and protein expression in the aortic wall. Even if further studies are required to elucidate its role in AAA development, ARG1 could represent a new prognostic or therapeutic target in aneurysmal disease.


Asunto(s)
Anticuerpos Neutralizantes , Aorta Abdominal/enzimología , Aneurisma de la Aorta Abdominal/enzimología , Arginasa/metabolismo , Macrófagos/enzimología , Elastasa Pancreática , Factor de Crecimiento Transformador beta/metabolismo , Animales , Aorta Abdominal/inmunología , Aorta Abdominal/patología , Aneurisma de la Aorta Abdominal/inducido químicamente , Aneurisma de la Aorta Abdominal/inmunología , Aneurisma de la Aorta Abdominal/patología , Modelos Animales de Enfermedad , Humanos , Mediadores de Inflamación/metabolismo , Macrófagos/inmunología , Macrófagos/patología , Masculino , Ratones Endogámicos C57BL , Fenotipo , Transducción de Señal , Factor de Crecimiento Transformador beta/inmunología , Regulación hacia Arriba
11.
Circ Res ; 121(3): 234-243, 2017 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-28607102

RESUMEN

RATIONALE: Necrotic core formation during the development of atherosclerosis is associated with a chronic inflammatory response and promotes accelerated plaque development and instability. However, the molecular links between necrosis and the development of atherosclerosis are not completely understood. Clec9a (C-type lectin receptor) or DNGR-1 (dendritic cell NK lectin group receptor-1) is preferentially expressed by the CD8α+ subset of dendritic cells (CD8α+ DCs) and is involved in sensing necrotic cells. We hypothesized that sensing of necrotic cells by DNGR-1 plays a determinant role in the inflammatory response of atherosclerosis. OBJECTIVE: We sought to address the impact of total, bone marrow-restricted, or CD8α+ DC-restricted deletion of DNGR-1 on atherosclerosis development. METHODS AND RESULTS: We show that total absence of DNGR-1 in Apoe (apolipoprotein e)-deficient mice (Apoe-/-) and bone marrow-restricted deletion of DNGR-1 in Ldlr (low-density lipoprotein receptor)-deficient mice (Ldlr-/-) significantly reduce inflammatory cell content within arterial plaques and limit atherosclerosis development in a context of moderate hypercholesterolemia. This is associated with a significant increase of the expression of interleukin-10 (IL-10). The atheroprotective effect of DNGR-1 deletion is completely abrogated in the absence of bone marrow-derived IL-10. Furthermore, a specific deletion of DNGR-1 in CD8α+ DCs significantly increases IL-10 expression, reduces macrophage and T-cell contents within the lesions, and limits the development of atherosclerosis. CONCLUSIONS: Our results unravel a new role of DNGR-1 in regulating vascular inflammation and atherosclerosis and potentially identify a new target for disease modulation.


Asunto(s)
Aterosclerosis/metabolismo , Aterosclerosis/patología , Células Dendríticas/metabolismo , Células Dendríticas/patología , Interleucina-10/biosíntesis , Lectinas Tipo C/deficiencia , Receptores Inmunológicos/deficiencia , Animales , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados
12.
Liver Int ; 38(1): 102-112, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-28665498

RESUMEN

BACKGROUND & AIMS: Recent studies suggest that heparins reduce liver fibrosis and the risk of decompensation of liver disease. Here, we evaluated the effects of enoxaparin in several experimental models of advanced cirrhosis. METHODS: Cirrhosis was induced in male Sprague-Dawley (SD) rats by: (i) Oral gavage with carbon tetrachloride (CCl4ORAL ), (ii) Bile duct ligation (BDL) and (iii) CCl4 inhalation (CCl4INH ). Rats received saline or enoxaparin s.c. (40 IU/Kg/d or 180 IU/Kg/d) following various protocols. Blood biochemical parameters, liver fibrosis, endothelium- and fibrosis-related genes, portal pressure, splenomegaly, bacterial translocation, systemic inflammation and survival were evaluated. Endothelial dysfunction was assessed by in situ bivascular liver perfusions. RESULTS: Enoxaparin did not ameliorate liver function, liver fibrosis, profibrogenic gene expression, portal hypertension, splenomegaly, ascites development and infection, serum IL-6 levels or survival in rats with CCl4ORAL or BDL-induced cirrhosis. Contrarily, enoxaparin worsened portal pressure in BDL rats and decreased survival in CCl4ORAL rats. In CCl4INH rats, enoxaparin had no effects on hepatic endothelial dysfunction, except for correcting the hepatic arterial dysfunction when enoxaparin was started with the CCl4 exposure. In these rats, however, enoxaparin increased liver fibrosis and the absolute values of portal venous and sinusoidal resistance. CONCLUSIONS: Our results do not support a role of enoxaparin for improving liver fibrosis, portal hypertension or endothelial dysfunction in active disease at advanced stages of cirrhosis. These disease-related factors and the possibility of a limited therapeutic window should be considered in future studies evaluating the use of anticoagulants in cirrhosis.


Asunto(s)
Anticoagulantes/farmacología , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Enoxaparina/farmacología , Hipertensión Portal/prevención & control , Cirrosis Hepática Experimental/prevención & control , Hígado/efectos de los fármacos , Presión Portal/efectos de los fármacos , Animales , Anticoagulantes/toxicidad , Traslocación Bacteriana/efectos de los fármacos , Biomarcadores/sangre , Coagulación Sanguínea/efectos de los fármacos , Enfermedad Hepática Inducida por Sustancias y Drogas/sangre , Enfermedad Hepática Inducida por Sustancias y Drogas/patología , Enfermedad Hepática Inducida por Sustancias y Drogas/fisiopatología , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Células Endoteliales/patología , Enoxaparina/toxicidad , Hipertensión Portal/sangre , Hipertensión Portal/patología , Hipertensión Portal/fisiopatología , Mediadores de Inflamación/sangre , Hígado/metabolismo , Hígado/patología , Circulación Hepática/efectos de los fármacos , Cirrosis Hepática Experimental/sangre , Cirrosis Hepática Experimental/patología , Cirrosis Hepática Experimental/fisiopatología , Masculino , Microcirculación/efectos de los fármacos , Ratas Sprague-Dawley
14.
Arterioscler Thromb Vasc Biol ; 37(11): 2171-2181, 2017 11.
Artículo en Inglés | MEDLINE | ID: mdl-28912363

RESUMEN

OBJECTIVE: Current experimental models of abdominal aortic aneurysm (AAA) do not accurately reproduce the major features of human AAA. We hypothesized that blockade of TGFß (transforming growth factor-ß) activity-a guardian of vascular integrity and immune homeostasis-would impair vascular healing in models of nondissecting AAA and would lead to sustained aneurysmal growth until rupture. APPROACH AND RESULTS: Here, we test this hypothesis in the elastase-induced AAA model in mice. We analyze AAA development and progression using ultrasound in vivo, synchrotron-based ultrahigh resolution imaging ex vivo, and a combination of biological, histological, and flow cytometry-based cellular and molecular approaches in vitro. Systemic blockade of TGFß using a monoclonal antibody induces a transition from a self-contained aortic dilatation to a model of sustained aneurysmal growth, associated with the formation of an intraluminal thrombus. AAA growth is associated with wall disruption but no medial dissection and culminates in fatal transmural aortic wall rupture. TGFß blockade enhances leukocyte infiltration both in the aortic wall and the intraluminal thrombus and aggravates extracellular matrix degradation. Early blockade of IL-1ß or monocyte-dependent responses substantially limits AAA severity. However, blockade of IL-1ß after disease initiation has no effect on AAA progression to rupture. CONCLUSIONS: Endogenous TGFß activity is required for the healing of AAA. TGFß blockade may be harnessed to generate new models of AAA with better relevance to the human disease. We expect that the new models will improve our understanding of the pathophysiology of AAA and will be useful in the identification of new therapeutic targets.


Asunto(s)
Anticuerpos Monoclonales/toxicidad , Aorta Abdominal/efectos de los fármacos , Aneurisma de la Aorta Abdominal/inducido químicamente , Rotura de la Aorta/inducido químicamente , Elastasa Pancreática , Factor de Crecimiento Transformador beta/antagonistas & inhibidores , Remodelación Vascular/efectos de los fármacos , Animales , Aorta Abdominal/inmunología , Aorta Abdominal/metabolismo , Aorta Abdominal/patología , Aneurisma de la Aorta Abdominal/inmunología , Aneurisma de la Aorta Abdominal/metabolismo , Aneurisma de la Aorta Abdominal/patología , Rotura de la Aorta/inmunología , Rotura de la Aorta/metabolismo , Rotura de la Aorta/patología , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Quimiotaxis de Leucocito/efectos de los fármacos , Dilatación Patológica , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Matriz Extracelular/efectos de los fármacos , Matriz Extracelular/metabolismo , Matriz Extracelular/patología , Interleucina-1beta/metabolismo , Cinética , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Sincrotrones , Trombosis/inducido químicamente , Trombosis/metabolismo , Trombosis/patología , Factor de Crecimiento Transformador beta/inmunología , Factor de Crecimiento Transformador beta/metabolismo , Ultrasonografía , Cicatrización de Heridas/efectos de los fármacos
15.
Circulation ; 134(14): 1039-1051, 2016 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-27587433

RESUMEN

BACKGROUND: Atherosclerotic lesion expansion is characterized by the development of a lipid-rich necrotic core known to be associated with the occurrence of complications. Abnormal lipid handling, inflammation, and alteration of cell survival or proliferation contribute to necrotic core formation, but the molecular mechanisms involved in this process are not properly understood. C-type lectin receptor 4e (Clec4e) recognizes the cord factor of Mycobacterium tuberculosis but also senses molecular patterns released by necrotic cells and drives inflammation. METHODS: We hypothesized that activation of Clec4e signaling by necrosis is causally involved in atherogenesis. We addressed the impact of Clec4e activation on macrophage functions in vitro and on the development of atherosclerosis using low-density lipoprotein receptor-deficient (Ldlr-/-) mice in vivo. RESULTS: We show that Clec4e is expressed within human and mouse atherosclerotic lesions and is activated by necrotic lesion extracts. Clec4e signaling in macrophages inhibits cholesterol efflux and induces a Syk-mediated endoplasmic reticulum stress response, leading to the induction of proinflammatory mediators and growth factors. Chop and Ire1a deficiencies significantly limit Clec4e-dependent effects, whereas Atf3 deficiency aggravates Clec4e-mediated inflammation and alteration of cholesterol efflux. Repopulation of Ldlr-/- mice with Clec4e-/- bone marrow reduces lipid accumulation, endoplasmic reticulum stress, and macrophage inflammation and proliferation within the developing arterial lesions and significantly limits atherosclerosis. CONCLUSIONS: Our results identify a nonredundant role for Clec4e in coordinating major biological pathways involved in atherosclerosis and suggest that it may play similar roles in other chronic inflammatory diseases.


Asunto(s)
Aterosclerosis/metabolismo , Lectinas Tipo C/metabolismo , Macrófagos/metabolismo , Proteínas de la Membrana/metabolismo , Receptores Inmunológicos/metabolismo , Respuesta de Proteína Desplegada/fisiología , Animales , Aterosclerosis/patología , Humanos , Inflamación/patología , Mediadores de Inflamación/metabolismo , Lectinas Tipo C/genética , Lipoproteínas LDL/metabolismo , Proteínas de la Membrana/genética , Ratones , Ratones Noqueados , Necrosis/metabolismo , Necrosis/patología , Fenotipo , Receptores de LDL/genética , Receptores de LDL/metabolismo
16.
Proc Natl Acad Sci U S A ; 111(12): E1101-10, 2014 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-24616502

RESUMEN

CD31 is a transhomophilic tyrosine-based inhibitory motif receptor and is expressed by both dendritic cells (DCs) and T lymphocytes. Previous studies have established that the engagement of CD31 drives immune-inhibitory signaling in T lymphocytes, but the effect exerted by CD31 signaling in DCs remains elusive. Here, we show that CD31 is a key coinhibitory receptor on stimulated DCs, favoring the development of tolerogenic functions and finally resulting in T-cell tolerance. The disruption of CD31 signaling favored the immunogenic maturation and migration of resident DCs to the draining lymph nodes. In contrast, sustaining the CD31/SHP-1 signaling during DC maturation resulted in reduced NF-κB nuclear translocation, expression of costimulatory molecules, and production of immunogenic cytokines (e.g., IL-12, IL-6), whereas the expression of TGF-ß and IL-10 were increased. More importantly, CD31-conditioned DCs purified from the draining lymph nodes of ovalbumin-immunized mice favored the generation of antigen-specific regulatory T cells (CD25(+) forkhead box P3(+)) at the expense of effector (IFN-γ(+)) cells upon coculture with naive ovalbumin-specific CD4(+) T lymphocytes ex vivo. Finally, the adoptive transfer of CD31-conditioned myelin oligodendrocyte glycoprotein-loaded DCs carried immune tolerance against the subsequent development of MOG-induced experimental autoimmune encephalomyelitis in vivo. The key coinhibitory role exerted by CD31 on DCs highlighted by the present study may have important implications both in settings where the immunogenic function of DCs is desirable, such as infection and cancer, and in settings where tolerance-driving DCs are preferred, such as autoimmune diseases and transplantation.


Asunto(s)
Células Dendríticas/inmunología , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/inmunología , Animales , Diferenciación Celular , Movimiento Celular , Células Dendríticas/citología , Citometría de Flujo , Inmunofenotipificación , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/genética , Transducción de Señal
17.
Circulation ; 131(6): 560-70, 2015 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-25552357

RESUMEN

BACKGROUND: The atheromodulating activity of B cells during the development of atherosclerosis is well documented, but the mechanisms by which these cells are regulated have not been investigated. METHODS AND RESULTS: Here, we analyzed the contribution of Qa-1-restricted CD8(+) regulatory T cells to the control of the T follicular helper-germinal center B-cell axis during atherogenesis. Genetic disruption of CD8(+) regulatory T cell function in atherosclerosis-prone apolipoprotein E knockout mice resulted in overactivation of this axis in secondary lymphoid organs, led to the increased development of tertiary lymphoid organs in the aorta, and enhanced disease development. In contrast, restoring control of the T follicular helper-germinal center B-cell axis by blocking the ICOS-ICOSL pathway reduced the development of atherosclerosis and the formation of tertiary lymphoid organs. Moreover, analyses of human atherosclerotic aneurysmal arteries by flow cytometry, gene expression analysis, and immunofluorescence confirmed the presence of T follicular helper cells within tertiary lymphoid organs. CONCLUSIONS: This study is the first to demonstrate that the T follicular helper-germinal center B-cell axis is proatherogenic and that CD8(+) regulatory T cells control the germinal center reaction in both secondary and tertiary lymphoid organs. Therefore, disrupting this axis represents an innovative therapeutic approach.


Asunto(s)
Aterosclerosis/inmunología , Linfocitos B/inmunología , Linfocitos T CD8-positivos/inmunología , Centro Germinal/inmunología , Adventicia/inmunología , Adventicia/patología , Animales , Femenino , Humanos , Técnicas In Vitro , Ligando Coestimulador de Linfocitos T Inducibles/inmunología , Ligando Coestimulador de Linfocitos T Inducibles/metabolismo , Ratones , Ratones Noqueados , Linfocitos T Reguladores
18.
J Cell Sci ; 126(Pt 11): 2343-52, 2013 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-23761922

RESUMEN

Although it is expressed by all leukocytes, including T-, B-lymphocytes and dendritic cells, the immunoglobulin-like receptor CD31 is generally regarded by immunologists as a marker of endothelial cell lineage that lacks an established functional role in adaptive immunity. This perception has recently been challenged by studies that reveal a key role for this molecule in the regulation of T-cell homeostasis, effector function and trafficking. The complexity of the biological functions of CD31 results from the integration of its adhesive and signaling functions in both the immune and vascular systems. Signaling by means of CD31 is induced by homophilic engagement during the interactions of immune cells and is mediated by phosphatase recruitment or activation through immunoreceptor tyrosine inhibitory motifs (ITIMs) that are located in its cytoplasmic tail. Loss of CD31 function is associated with excessive immunoreactivity and susceptibility to cytotoxic killing. Here, we discuss recent findings that have brought to light a non-redundant, complex role for this molecule in the regulation of T-cell-mediated immune responses, with large impact on our understanding of immunity in health and disease.


Asunto(s)
Movimiento Celular/inmunología , Inmunidad Celular , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/inmunología , Transducción de Señal/inmunología , Linfocitos T/inmunología , Animales , Adhesión Celular/genética , Adhesión Celular/inmunología , Movimiento Celular/genética , Humanos , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/genética , Transducción de Señal/genética
19.
J Autoimmun ; 63: 59-67, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26183767

RESUMEN

Cardiovascular disease due to accelerated atherosclerosis is the leading cause of death in patients with systemic lupus erythematosus (SLE). Noteworthy, accelerated atherosclerosis in SLE patients appears to be independant of classical Framingham risk factors. This suggests that aggravated atherosclerosis in SLE patients may be a result of increased inflammation and altered immune responses. However, the mechanisms that mediate the acceleration of atherosclerosis in SLE remain elusive. Based on experimental data which includes both humans (SLE patients and control subjects) and rodents (ApoE-/- mice), we herein propose a multi-step model in which the immune dysfunction associated with SLE (i.e. high level of IFN-α production by TLR 9-stimulated pDCs) is associated with, first, an increased frequency of circulating pro inflammatory CD4+CXCR3+ T cells; second, an increased production of CXCR3 ligands by endothelial cells; third, an increased recruitment of pro-inflammatory CD4+CXCR3+ T cells into the arterial wall, and fourth, the development of atherosclerosis. In showing how SLE may promote accelerated atherosclerosis, our model also points to hypotheses for potential interventions, such as pDCs-targeted therapy, that might be studied in the future.


Asunto(s)
Aterosclerosis/etiología , Linfocitos T CD4-Positivos/metabolismo , Células Dendríticas/metabolismo , Lupus Eritematoso Sistémico/complicaciones , Receptores CXCR3 , Animales , Aterosclerosis/inmunología , Linfocitos T CD4-Positivos/inmunología , Células Dendríticas/inmunología , Humanos , Lupus Eritematoso Sistémico/inmunología , Ratones , Ratones Noqueados , Modelos Inmunológicos
20.
J Autoimmun ; 56: 23-33, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25277651

RESUMEN

CD31, a trans-homophilic inhibitory receptor expressed on both T- and B-lymphocytes, drives the mutual detachment of interacting leukocytes. Intriguingly, T cell CD31 molecules relocate to the immunological synapse (IS), where the T and B cells establish a stable interaction. Here, we show that intact CD31 molecules, which are able to drive an inhibitory signal, are concentrated at the periphery of the IS but are excluded from the center of the IS. At this site, were the cells establish the closest contact, the CD31 molecules are cleaved, and most of the extracellular portion of the protein, including the trans-homophilic binding sites, is shed from the cell surface. T cells lacking CD31 trans-homophilic binding sites easily establish stable interactions with B cells; at the opposite, CD31 signaling agonists inhibit T/B IS formation as well as the ensuing helper T cell activation and function. Confocal microscopy and flow cytometry analysis of experimental T/B IS shows that the T cell inhibitory effects of CD31 agonists depend on SHP-2 signaling, which reduces the phosphorylation of ZAP70. The analysis of synovial tissue biopsies from patients affected by rheumatoid arthritis showed that T cell CD31 molecules are excluded from the center of the T/B cell synapses in vivo. Interestingly, the administration of CD31 agonists in vivo significantly attenuated the development of the clinical signs of collagen-induced arthritis in DBA1/J mice. Altogether, our data indicate that the T cell co-inhibitory receptor CD31 prevents the formation of functional T/B immunological synapses and that therapeutic strategies aimed at sustaining CD31 signaling will attenuate the development of autoimmune responses in vivo.


Asunto(s)
Artritis Experimental/inmunología , Enfermedades Autoinmunes/inmunología , Linfocitos B/inmunología , Sinapsis Inmunológicas/inmunología , Sinapsis Inmunológicas/metabolismo , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Anciano , Animales , Artritis Experimental/metabolismo , Enfermedades Autoinmunes/diagnóstico , Enfermedades Autoinmunes/metabolismo , Biopsia , Comunicación Celular/efectos de los fármacos , Comunicación Celular/inmunología , Línea Celular , Femenino , Humanos , Activación de Linfocitos/inmunología , Ratones , Persona de Mediana Edad , Proteína Tirosina Fosfatasa no Receptora Tipo 11/metabolismo , Transducción de Señal , Membrana Sinovial/inmunología , Membrana Sinovial/patología , Subgrupos de Linfocitos T/efectos de los fármacos , Proteína Tirosina Quinasa ZAP-70/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA